Dwarf Fortress Wiki - User contributions [en]

Tracker

2016-04-03T04:28:04Z

NW Kohaku:

{{Quality|Fine|21:55, 30 December 2010 (UTC)}}
{{Skill
| color = 3:0
| skill = Tracker
| profession = Unknown
| job name = None
| tasks = None
| attributes =
* Unknown
}}
{{av}}

Tracker is a [[skill]] currently only used in [[Adventurer mode]] which allows an adventurer to track creatures. Higher levels let you spot more tracks and help distinguish different tracks.

Historical figures that have done scouting, beast hunting or wandering in the past always seem to have some level of this skill.

In fortress mode, this is used by [[scholar]]s who are [[naturalist]]s.

{{skills}}

Skill

2016-04-02T18:13:28Z

NW Kohaku: /* Skills in use */

{{Quality|Exceptional|01:07, 4 February 2015 (UTC)}}
{{av}}
''See also: [[Combat skill]]''

'''Skills''' are used by dwarves to accomplish almost every task in the game. A higher level of a skill allows a dwarf to accomplish the respective task more quickly and/or more effectively. Whenever a skill is used, [[experience]] is gained for that skill, allowing the dwarf to progress to higher skill levels.

If a dwarf does not use a skill for a prolonged period of time, the skill will be labeled "rusty." If the rusty skill continues to remain unused, it will eventually be labeled "very rusty," or "V rusty" in game. Skills remaining at very rusty for prolonged periods of time will gradually suffer permanent experience loss. It is not possible in-game to know whether a given skill has suffered level loss, but any utility capable of reading exact XP levels will show a skill with a lost level as being at 100% of the XP required to take it to the next skill level. See [[#Skill rust|Rust]] below for more details.

To determine what skills a dwarf has, press {{K|v}} and highlight the dwarf, then press {{K|g}} to ensure you are on the general information page. The skills will be grouped into three toggleable types: {{K|c}}ombat, la{{K|b}}or and {{K|m}}iscellaneous skills. Included on the list are the levels of each skill, and, if applicable, "rusty" or "V rusty" notifications.

== Skill level names ==

The names of skill levels are as follows, in order of the experience required to achieve them:
* Not (No skill)
* {{Raw Tile|Dabbling|6:0:0}}
* {{Raw Tile|Novice|7:0:0}}
* {{Raw Tile|Adequate|7:0:1}}
* {{Raw Tile|Competent|3:0:0}}
* {{Raw Tile|Skilled|3:0:0}}
* {{Raw Tile|Proficient|3:0:0}}
* {{Raw Tile|Talented|3:0:1}}
* {{Raw Tile|Adept|3:0:1}}
* {{Raw Tile|Expert|3:0:1}}
* {{Raw Tile|Professional|2:0:1}}
* {{Raw Tile|Accomplished|2:0:1}}
* {{Raw Tile|Great|2:0:1}}
* {{Raw Tile|Master|2:0:1}}
* {{Raw Tile|High Master|2:0:1}}
* {{Raw Tile|Grand Master|2:0:1}}
* {{Raw Tile|Legendary|5:0:1}}

== Skills in use ==
Skills are never referred to in-game by "level number", but for all practical purposes, that is how they are treated by the game. "Dabbling" is not functionally a level, with "Novice" being level 1, and "Legendary" being any level 15 and up.

All skills take (400 + 100 * the new level)experience points to gain a level, meaning Novice takes 500 experience points, and reaching Legendary from Grand Master takes 1900 experience points, or 18000 total experience.

Many skills can gain practical levels beyond level 15, or "Legendary". Crafting skills with quality have a functional maximum of level 20, or "Legendary +5" as it is often called. This is used in determining [[item quality], where skill level is tested with a series of "dice rolls" against successively higher targets. A Legendary +5 dwarf has a skill level of 20, which means they are guaranteed exceptional quality (quality level 4) unless they "critically fail" one of the quality rolls, and they additionally have a fairly decent percentage roll to succeed at making a masterwork. [[Attributes]] and [[trait]]s now play a role in crafting, however, so there are subtle layers of complexity in that.

Labors with or without quality often have a time period associated with them, and skill levels reduce this significantly. Legendary +5 can eliminate all time required to do a job down to a single action, exponentially increasing productivity.

Combat skills can scale upwards to a functionally impossible to reach degree, meaning that simply reaching Legendary in a combat skill only means they've just started climbing the ranks of the legendary warriors of Dwarf Fortress. A Legendary +100 warrior will more regularly hit and deal more damage than a "mere" Legendary +10, although it takes nearly three-quarters of a million more experience points to get there.

==Skill penalties==
Dwarves that are [[status icon|hungry, tired, or thirsty]] will work slower and produce lower quality goods. This is unimportant for some tasks such as wood cutting or furnace operating but you may want to halt construction of [[aluminum]] [[statue]]s if your [[blacksmith]] is famished and hollow-eyed from lack of sleep.

==Skills==

{| style="margin: 0 auto"
|-
| valign='top' |

{{Skill Box|Miner|7:0|7:0|
* [[Miner]]
}}

{{Skill Box|[[Woodworker]]|6:1|6:1|
* [[Bowyer]]
* [[Carpenter]]
* [[Wood cutter]]
}}

{{Skill Box|[[Stoneworker]]|7:1|7:1|
* [[Engraver]]
* [[Mason]]
}}

{{Skill Box|[[Ranger]]|2:0|2:0|
* [[Ambusher]]
* [[Animal caretaker]]
* [[Animal dissector]]
* [[Animal trainer]]
* [[Trapper]]
}}

{{Skill Box|[[Doctor]]|5:0|5:0|
* [[Bone doctor]]
* [[Crutch-walker]]
* [[Diagnostician]]
* [[Surgeon]]
* [[Suturer]]
* [[Wound dresser]]
}}

| valign='top' |

{{Skill Box|[[Farmer]]|6:0|6:0|
* [[Beekeeper]]
* [[Brewer]]
* [[Butcher]]
* [[Cheese maker]]
* [[Cook]]
* [[Dyer]]
* [[Gelder]]
* [[Grower]]
* [[Herbalist]]
* [[Lye maker]]
* [[Milker]]
* [[Miller]]
* [[Potash maker]]
* [[Presser]]
* [[Shearer]]
* [[Soaper]]
* [[Spinner]]
* [[Tanner]]
* [[Thresher]]
* [[Wood burner]]
}}

{{Skill Box|[[Fishery worker]]|1:0|1:0|
* [[Fish cleaner]]
* [[Fish dissector]]
* [[Fisherdwarf]]
}}

{{Skill Box|[[Metalsmithing|Metalsmith]]|0:1|0:1|
* [[Armorsmith]]
* [[Furnace operator]]
* [[Metal crafter]]
* [[Blacksmith|Metalsmith]]
* [[Weaponsmith]]
}}

| valign='top' |

{{Skill Box|[[Jeweler]]|2:1|2:1|
* [[Gem cutter]]
* [[Gem setter]]
}}

{{Skill Box|[[Craftsdwarf]]|1:1|1:1|
* [[Bookbinder]]
* [[Bone carver]]
* [[Clothier]]
* [[Glassmaker]]
* [[Glazer]]
* [[Leatherworker]]
* [[Papermaker]]
* [[Potter]]
* [[Stone crafter]]
* [[Strand extractor]]
* [[Wax worker]]
* [[Weaver]]
* [[Wood crafter]]
}}

{{Skill Box|[[Engineer]]|4:1|4:1|
* [[Mechanic]]
* [[Pump operator]]
* [[Siege engineer]]
* [[Siege operator]]
}}

{{Skill Box|Other Jobs|3:0|3:0|
* [[Alchemy|Alchemist]]
* [[Knapper]]
}}

{{Skill Box|[[Administrator]]|5:0|5:0|
* [[Appraiser]]
* [[Building designer]]
* [[Organizer]]
* [[Record keeper]]
}}

| valign='top' |

{{Skill Box|[[Military]]|0:1|0:0|
* [[Archer]]
* [[Armor user]]
* [[Axeman]]
* [[Biter]]
* [[Blowgunner]]
* [[Bowman]]
* [[Crossbowman]]
* [[Dodger]]
* [[Discipline]]
* [[Fighter]]
* [[Hammerman]]
* [[Kicker]]
* [[Knife user]]
* [[Lasher]]
* [[Maceman]]
* [[Misc. object user]]
* [[Pikeman]]
* [[Shield user]]
* [[Spearman]]
* [[Striker]]
* [[Swordsman]]
* [[Thrower]]
* [[Wrestler]]
}}

{{Skill Box|[[Broker]]|3:0|3:0|
* [[Comedian]]
* [[Conversationalist]]
* [[Flatterer]]
* [[Intimidator]]
* [[Judge of intent]]
* [[Liar]]
* [[Negotiator]]
* [[Persuader]]
}}

| valign='top' |

{{Skill Box|Miscellaneous|3:0|3:0|
* [[Climber]]
* [[Concentration]]
* [[Consoler]]
* [[Leader]]
* [[Observer]]
* [[Pacifier]]
* [[Reader]]
* [[Student]]
* [[Swimmer]]
* [[Teacher]]
* [[Tracker]]
}}

{{Skill Box|Performance|3:0|3:0|
* [[Dancer]]
* [[Singer]]
* [[Musician]]
* [[Poet]]
* [[Speaker]]
* [[Keyboardist]]
* [[Stringed instrumentalist]]
* [[Wind instrumentalist]]
* [[Percussionist]]
}}

{{Skill Box|Scholar|3:0|3:0|
* [[Critical thinker]]
* [[Logician]]
* [[Mathematician]]
* [[Astronomer]]
* [[Chemist]]
* [[Geographer]]
* [[Optics engineer]]
* [[Fluid engineer]]
* [[Wordsmith]]
* [[Writer]]
}}

{{Skill Box|Unused|3:0|3:0|
* [[Balance]]
* [[Coordination]]
* [[Druid]]
* [[Military tactics]]
}}

|}

==Skills, attributes and traits==
*'''Skills''':
**are trained by being used in some activity.
**train '''[[attribute]]s'''.
**the same [[attribute]] can be trained by various skills.
**it's assumed that the skills also use some of the [[attribute]]s that they train.
**certain skills are required or important for certain [[noble]], [[military]] and civilian professions.
**certain professions require several skills.
**the same skill can be used by various professions.
**are increased by [[Preferences]], but capped, so the dwarf will make items beyond its skill level but won't affect the chances of making more high value items at the highest skill level.

*'''[[Personality trait|Traits]]''':
**cannot be modified in-game.{{verify}}
**affect which [[social skill]]s gain experience ''(if the dwarf has X trait it will not gain experience in X skill)'' at all.
**have other in-game effects that can be useful for certain professions.
**give [[thought]]s when performing certain activities.

To summarize it goes like this:
Trait --> Skill <--> Attribute
| ^
v |
affect |
| v
'--> Profession

Since the same skills can be used by various professions, and the same [[attribute]]s are trained by various skills, this allows for [[cross-training]].

Being [[Personality trait|traits]] the unmodifiable{{verify}}, limiting factor on which skills can be learned or having useful effects, and certain professions requiring various skills, the need arises to:
*avoid appointing a dwarf that will never learn a certain skill to a profession that uses it:
**''appointing a [[Personality trait|straightforward]] dwarf as a [[broker]] will result in a [[consoler]], non-[[flatterer]], non-[[liar]] [[broker]]''.
*appoint a dwarf with a useful effect given by a [[Personality trait|trait]] to a profession that benefits from it:
**''appointing an [[Personality trait|undisciplined]] dwarf to an important job will result in [[fun|fun]]''.
**''appointing an [[Personality trait|angry]] dwarf to [[soldier]] will result in more [[Status_icon|enraged]] bonuses.

==Skill rust==
Every skill has the following set of improvement and decay counters, which are caste specific:

{{token|SKILL_RATE|c}} (Default is {{token|SKILL_RATE|cr|100:8:16:16}})
* % of improvement points you get (Default 100)
* unused counter rate (Default 8)
* rust counter rate (Default 16)
* demotion counter rate (Default 16)

The unused counter starts incrementing while a dwarf isn't using a skill. Once it reaches the cap, it will reset to zero, and the rust counter rate will increment by 1. This continues until the rust counter's cap is reached, and then the demotion counter is incremented by 1, and the rust counter is reset to zero. When the demotion counter finally reaches its cap, a 'layer' of rust is added to the skill, and the demotion counter is reset to zero.

The {{DFtext|Rusty}} and {{DFtext|V.Rusty}} descriptions which are appended to a skill within Dwarf Fortress are determined by the following conditions:

*Rusty: A skill level greater than 0 and less than 4, and the skill level * 0.5 <= the number of rust layers.
*Very Rusty: A skill level greater than or equal to 4, and the skill level * 0.75 <= the number of rust layers.

For example, a level 3 skill with 4 layers of rust: 3 * 0.5 = 1.5 which is less than the 4 layers of rust, so it's a Rusty skill. A level 8 with 6 layers of rust: 8 * 0.75 = 6 which is equal to the layers of rust, so it's a Very Rusty skill.

In testing it appears that the layers of rust are limited to a maximum of 6. If the counters reach the maximum and it attempts to increase to a 7th layer of rust, all counters are stopped, and the 'Rusty' and 'V. Rusty' descriptions are erroneously removed from the skill descriptions within Dwarf Fortress.

{{Category|Skills| }}

Skill

2016-04-02T15:41:36Z

NW Kohaku:

{{Quality|Exceptional|01:07, 4 February 2015 (UTC)}}
{{av}}
''See also: [[Combat skill]]''

'''Skills''' are used by dwarves to accomplish almost every task in the game. A higher level of a skill allows a dwarf to accomplish the respective task more quickly and/or more effectively. Whenever a skill is used, [[experience]] is gained for that skill, allowing the dwarf to progress to higher skill levels.

If a dwarf does not use a skill for a prolonged period of time, the skill will be labeled "rusty." If the rusty skill continues to remain unused, it will eventually be labeled "very rusty," or "V rusty" in game. Skills remaining at very rusty for prolonged periods of time will gradually suffer permanent experience loss. It is not possible in-game to know whether a given skill has suffered level loss, but any utility capable of reading exact XP levels will show a skill with a lost level as being at 100% of the XP required to take it to the next skill level. See [[#Skill rust|Rust]] below for more details.

To determine what skills a dwarf has, press {{K|v}} and highlight the dwarf, then press {{K|g}} to ensure you are on the general information page. The skills will be grouped into three toggleable types: {{K|c}}ombat, la{{K|b}}or and {{K|m}}iscellaneous skills. Included on the list are the levels of each skill, and, if applicable, "rusty" or "V rusty" notifications.

== Skill level names ==

The names of skill levels are as follows, in order of the experience required to achieve them:
* Not (No skill)
* {{Raw Tile|Dabbling|6:0:0}}
* {{Raw Tile|Novice|7:0:0}}
* {{Raw Tile|Adequate|7:0:1}}
* {{Raw Tile|Competent|3:0:0}}
* {{Raw Tile|Skilled|3:0:0}}
* {{Raw Tile|Proficient|3:0:0}}
* {{Raw Tile|Talented|3:0:1}}
* {{Raw Tile|Adept|3:0:1}}
* {{Raw Tile|Expert|3:0:1}}
* {{Raw Tile|Professional|2:0:1}}
* {{Raw Tile|Accomplished|2:0:1}}
* {{Raw Tile|Great|2:0:1}}
* {{Raw Tile|Master|2:0:1}}
* {{Raw Tile|High Master|2:0:1}}
* {{Raw Tile|Grand Master|2:0:1}}
* {{Raw Tile|Legendary|5:0:1}}

== Skills in use ==
Skills are never referred to in-game by "level number", but for all practical purposes, that is how they are treated by the game. "Dabbling" is not functionally a level, with "Novice" being level 1, and "Legendary" being any level 15 and up.

All skills take (400 + 100 * the new level)experience points to gain a level, meaning Novice takes 500 experience points, and reaching Legendary from Grand Master takes 1900 experience points, or 18000 total experience.

Many skills can gain practical levels beyond level 15, or "Legendary". Crafting skills with quality have a functional maximum of level 20, or "Legendary +5" as it is often called. This is used in determining [[item quality], where skill level is tested with a series of "dice rolls" against successively higher targets. A Legendary +5 dwarf has a skill level of 20, which means they are guaranteed exceptional quality (quality level 4) unless they "critically fail" one of the quality rolls, and they additionally have a fairly decent percentage roll to succeed at making a masterwork. [[Attributes]] and [[traits]] now play a role in crafting, however, so there are subtle layers of complexity in that.

Labors with or without quality often have a time period associated with them, and skill levels reduce this significantly. Legendary +5 can eliminate all time required to do a job down to a single action, exponentially increasing productivity.

Combat skills can scale upwards to a functionally impossible to reach degree, meaning that simply reaching Legendary in a combat skill only means they've just started climbing the ranks of the legendary warriors of Dwarf Fortress. A Legendary +100 warrior will more regularly hit and deal more damage than a "mere" Legendary +10, although it takes nearly three-quarters of a million more experience points to get there.

==Skill penalties==
Dwarves that are [[status icon|hungry, tired, or thirsty]] will work slower and produce lower quality goods. This is unimportant for some tasks such as wood cutting or furnace operating but you may want to halt construction of [[aluminum]] [[statue]]s if your [[blacksmith]] is famished and hollow-eyed from lack of sleep.

==Skills==

{| style="margin: 0 auto"
|-
| valign='top' |

{{Skill Box|Miner|7:0|7:0|
* [[Miner]]
}}

{{Skill Box|[[Woodworker]]|6:1|6:1|
* [[Bowyer]]
* [[Carpenter]]
* [[Wood cutter]]
}}

{{Skill Box|[[Stoneworker]]|7:1|7:1|
* [[Engraver]]
* [[Mason]]
}}

{{Skill Box|[[Ranger]]|2:0|2:0|
* [[Ambusher]]
* [[Animal caretaker]]
* [[Animal dissector]]
* [[Animal trainer]]
* [[Trapper]]
}}

{{Skill Box|[[Doctor]]|5:0|5:0|
* [[Bone doctor]]
* [[Crutch-walker]]
* [[Diagnostician]]
* [[Surgeon]]
* [[Suturer]]
* [[Wound dresser]]
}}

| valign='top' |

{{Skill Box|[[Farmer]]|6:0|6:0|
* [[Beekeeper]]
* [[Brewer]]
* [[Butcher]]
* [[Cheese maker]]
* [[Cook]]
* [[Dyer]]
* [[Gelder]]
* [[Grower]]
* [[Herbalist]]
* [[Lye maker]]
* [[Milker]]
* [[Miller]]
* [[Potash maker]]
* [[Presser]]
* [[Shearer]]
* [[Soaper]]
* [[Spinner]]
* [[Tanner]]
* [[Thresher]]
* [[Wood burner]]
}}

{{Skill Box|[[Fishery worker]]|1:0|1:0|
* [[Fish cleaner]]
* [[Fish dissector]]
* [[Fisherdwarf]]
}}

{{Skill Box|[[Metalsmithing|Metalsmith]]|0:1|0:1|
* [[Armorsmith]]
* [[Furnace operator]]
* [[Metal crafter]]
* [[Blacksmith|Metalsmith]]
* [[Weaponsmith]]
}}

| valign='top' |

{{Skill Box|[[Jeweler]]|2:1|2:1|
* [[Gem cutter]]
* [[Gem setter]]
}}

{{Skill Box|[[Craftsdwarf]]|1:1|1:1|
* [[Bookbinder]]
* [[Bone carver]]
* [[Clothier]]
* [[Glassmaker]]
* [[Glazer]]
* [[Leatherworker]]
* [[Papermaker]]
* [[Potter]]
* [[Stone crafter]]
* [[Strand extractor]]
* [[Wax worker]]
* [[Weaver]]
* [[Wood crafter]]
}}

{{Skill Box|[[Engineer]]|4:1|4:1|
* [[Mechanic]]
* [[Pump operator]]
* [[Siege engineer]]
* [[Siege operator]]
}}

{{Skill Box|Other Jobs|3:0|3:0|
* [[Alchemy|Alchemist]]
* [[Knapper]]
}}

{{Skill Box|[[Administrator]]|5:0|5:0|
* [[Appraiser]]
* [[Building designer]]
* [[Organizer]]
* [[Record keeper]]
}}

| valign='top' |

{{Skill Box|[[Military]]|0:1|0:0|
* [[Archer]]
* [[Armor user]]
* [[Axeman]]
* [[Biter]]
* [[Blowgunner]]
* [[Bowman]]
* [[Crossbowman]]
* [[Dodger]]
* [[Discipline]]
* [[Fighter]]
* [[Hammerman]]
* [[Kicker]]
* [[Knife user]]
* [[Lasher]]
* [[Maceman]]
* [[Misc. object user]]
* [[Pikeman]]
* [[Shield user]]
* [[Spearman]]
* [[Striker]]
* [[Swordsman]]
* [[Thrower]]
* [[Wrestler]]
}}

{{Skill Box|[[Broker]]|3:0|3:0|
* [[Comedian]]
* [[Conversationalist]]
* [[Flatterer]]
* [[Intimidator]]
* [[Judge of intent]]
* [[Liar]]
* [[Negotiator]]
* [[Persuader]]
}}

| valign='top' |

{{Skill Box|Miscellaneous|3:0|3:0|
* [[Climber]]
* [[Concentration]]
* [[Consoler]]
* [[Leader]]
* [[Observer]]
* [[Pacifier]]
* [[Reader]]
* [[Student]]
* [[Swimmer]]
* [[Teacher]]
* [[Tracker]]
}}

{{Skill Box|Performance|3:0|3:0|
* [[Dancer]]
* [[Singer]]
* [[Musician]]
* [[Poet]]
* [[Speaker]]
* [[Keyboardist]]
* [[Stringed instrumentalist]]
* [[Wind instrumentalist]]
* [[Percussionist]]
}}

{{Skill Box|Scholar|3:0|3:0|
* [[Critical thinker]]
* [[Logician]]
* [[Mathematician]]
* [[Astronomer]]
* [[Chemist]]
* [[Geographer]]
* [[Optics engineer]]
* [[Fluid engineer]]
* [[Wordsmith]]
* [[Writer]]
}}

{{Skill Box|Unused|3:0|3:0|
* [[Balance]]
* [[Coordination]]
* [[Druid]]
* [[Military tactics]]
}}

|}

==Skills, attributes and traits==
*'''Skills''':
**are trained by being used in some activity.
**train '''[[attribute]]s'''.
**the same [[attribute]] can be trained by various skills.
**it's assumed that the skills also use some of the [[attribute]]s that they train.
**certain skills are required or important for certain [[noble]], [[military]] and civilian professions.
**certain professions require several skills.
**the same skill can be used by various professions.
**are increased by [[Preferences]], but capped, so the dwarf will make items beyond its skill level but won't affect the chances of making more high value items at the highest skill level.

*'''[[Personality trait|Traits]]''':
**cannot be modified in-game.{{verify}}
**affect which [[social skill]]s gain experience ''(if the dwarf has X trait it will not gain experience in X skill)'' at all.
**have other in-game effects that can be useful for certain professions.
**give [[thought]]s when performing certain activities.

To summarize it goes like this:
Trait --> Skill <--> Attribute
| ^
v |
affect |
| v
'--> Profession

Since the same skills can be used by various professions, and the same [[attribute]]s are trained by various skills, this allows for [[cross-training]].

Being [[Personality trait|traits]] the unmodifiable{{verify}}, limiting factor on which skills can be learned or having useful effects, and certain professions requiring various skills, the need arises to:
*avoid appointing a dwarf that will never learn a certain skill to a profession that uses it:
**''appointing a [[Personality trait|straightforward]] dwarf as a [[broker]] will result in a [[consoler]], non-[[flatterer]], non-[[liar]] [[broker]]''.
*appoint a dwarf with a useful effect given by a [[Personality trait|trait]] to a profession that benefits from it:
**''appointing an [[Personality trait|undisciplined]] dwarf to an important job will result in [[fun|fun]]''.
**''appointing an [[Personality trait|angry]] dwarf to [[soldier]] will result in more [[Status_icon|enraged]] bonuses.

==Skill rust==
Every skill has the following set of improvement and decay counters, which are caste specific:

{{token|SKILL_RATE|c}} (Default is {{token|SKILL_RATE|cr|100:8:16:16}})
* % of improvement points you get (Default 100)
* unused counter rate (Default 8)
* rust counter rate (Default 16)
* demotion counter rate (Default 16)

The unused counter starts incrementing while a dwarf isn't using a skill. Once it reaches the cap, it will reset to zero, and the rust counter rate will increment by 1. This continues until the rust counter's cap is reached, and then the demotion counter is incremented by 1, and the rust counter is reset to zero. When the demotion counter finally reaches its cap, a 'layer' of rust is added to the skill, and the demotion counter is reset to zero.

The {{DFtext|Rusty}} and {{DFtext|V.Rusty}} descriptions which are appended to a skill within Dwarf Fortress are determined by the following conditions:

*Rusty: A skill level greater than 0 and less than 4, and the skill level * 0.5 <= the number of rust layers.
*Very Rusty: A skill level greater than or equal to 4, and the skill level * 0.75 <= the number of rust layers.

For example, a level 3 skill with 4 layers of rust: 3 * 0.5 = 1.5 which is less than the 4 layers of rust, so it's a Rusty skill. A level 8 with 6 layers of rust: 8 * 0.75 = 6 which is equal to the layers of rust, so it's a Very Rusty skill.

In testing it appears that the layers of rust are limited to a maximum of 6. If the counters reach the maximum and it attempts to increase to a 7th layer of rust, all counters are stopped, and the 'Rusty' and 'V. Rusty' descriptions are erroneously removed from the skill descriptions within Dwarf Fortress.

{{Category|Skills| }}

Minecart

2016-03-25T19:40:45Z

NW Kohaku: /* Sub-tile Positions and Velocity */ Correcting a demonstration's mistyped direction.

{{Quality|Masterwork|08:15, 19 May 2015 (UTC)}}
{{av}}
[[File:Leitnagel Hund.png|thumb|Minecarts]]
A '''minecart''' is a [[tool]] intended for [[hauling]], introduced in version 0.34.08. It can be made of [[wood]] at a [[carpenter's workshop]] or [[metal]] at a [[metalsmith's forge]] (using the [[Metal crafter|metalcrafting]] labor.) Minecarts store up to five times as many items as [[wheelbarrow]]s and are quite a bit faster than dwarves hauling objects by hand, but have the disadvantages of requiring a dedicated track network, a complex route planning phase, and the possibility of dwarves [[Fun|blundering into the path of carts filled with lead ore]]. Tracks may be carved into stone, or [[Construction|constructed]]; the latter allows above-ground routes, but these are more difficult to set up due to their additional [[building material|material requirements]].

Just like wheelbarrows, minecarts are considered [[item]]s and are stored in a [[furniture]] [[stockpile]]. Despite their five-times-greater capacity, they are only 33% larger than wheelbarrows and are identical in base [[item value|value]] when made from the same [[material]] (the value may differ due to the [[item quality]]). [[thief|Thieves]] or even mischievous animals can steal minecarts, even when they are moving on a track{{cite forum|109460/3289070}}. However, minecarts moving fast enough or being ridden cannot be stolen.

Although most of the utility of minecarts is in [[fortress mode]], an [[adventure mode|adventurer]] can also ride in a minecart. Adventurers can also pick up and relocate minecarts.

The invention of minecarts revolutionized the [[minecart logic|Science of Dwarfputing]] by enabling smaller, faster logic systems to be built.

== Basic Minecart Usage ==
Minecarts can be used to swiftly transport dwarves, [[flow|fluids]], and/or large amounts of items, but before you have a functional minecart there are several preconditions that need to be met. First of all you need an actual minecart, constructed either in a [[carpenter's workshop]] or [[metalsmith's forge]]. For the minecart to be able to move you also need to carve (with {{k|d}} {{k|T}}) or construct (with {{k|b}} {{k|C}} {{k|T}}) a track, which could be as simple as a straight line. Finally you need to construct stops on your track (with {{k|b}} {{k|C}} {{k|S}}) where the minecart will start and stop.

After you have created the stops and assigned a cart to the track, you must create logic routes connecting several stops and designate starting conditions for each stop. This is done with the {{k|h}}auling key. The most basic conditions are how the cart's movement is initiated and in which direction the cart should start moving. Carts can be either be Pushed (a dwarf stands at a stop and gives the cart a single push) or Guided (a dwarf continually pushes the cart forward, guiding it along the track). The [[hauling]] [[labor]] required for pushing and guiding carts is called "Push/Haul Vehicles" and is turned on by default.

To control which items to transport you can add conditions specifying: (1) which kind of items to be loaded, and unloaded, (2) stockpile links to define which stockpile(s) the items should be un/loaded to and from.

===Capacity and weights ===
Minecarts have five times the [[Weight|capacity]] of [[wheelbarrow]]s.

'''Examples of the capacity of one cart'''
{| class="wikitable"
|-
! Item
! Amount
|-
| [[stone]]
| 5
|-
| [[wood|log]]
| 10
|-
| [[block]]/[[bar]]
| 83
|-
| [[Kitchen|prepared meals]]
| 500
|-
| [[Trap_component#Spiked_ball|spiked balls]]
| 500
|-
| [[Weapon#Native_weapons|mace]]
| 625
|-
| [[Weapon#Native_weapons|spears]]
| 1250
|-
| [[cloth]]
| 2500
|}

The weight of the loaded minecart does not affect the initial velocity received from pushing or launching from a roller. However, the load of a minecart ''does'' affect whether a [[pressure plate]] triggers or not, based on the pressure plate's setting.

'''Weights of different carts'''

{| class="wikitable"
|-
! Type of cart
! Empty cart
! Fully loaded (items)
|-
| oaken minecart
| 28Γ
| 378Γ (10 oak logs)
|-
| platinum minecart
| 856Γ
| 10482Γ (83 gold bars)
|}

The weight of a minecart is one twenty-fifth (1/25) the [[density]] of its material in Urists. Because pressure plates can be set to trigger at intervals of 50 Urists, minecarts with weights just under a multiple of 50 are ideal for switching based on whether they're full or empty. The best minecart materials for full/empty switching are as follows:

{| class="wikitable sortable"
|-
! Material !! Minecart weight !! Content weight required to trigger !! Banana roasts required to trigger (for scale)
|-
| [[Glumprong]] || 48 || 2 || 4
|-
| [[Electrum]] || 596 || 4 || 7
|-
| [[Nickel silver]] || 346 || 4 || 7
|-
| [[Brass]] || 342 || 8 || 14
|-
| [[Bismuth]] (moods only) || 391 || 9 || 15
|-
| [[Fine pewter]] || 291 || 9 || 15
|-
| [[Lay pewter]] || 291 || 9 || 15
|-
| [[Tin]] || 291 || 9 || 15
|-
| [[Trifle pewter]] || 291 || 9 || 15
|}

=== Creating tracks ===
Minecart tracks are made up of contiguous track, tracked ramp, or bridge tiles. Track tiles and tracked ramp tiles have a direction or series of directions associated with them. These directions dictate which directions a minecart on a given tile may move from that tile. For example, a Track NE (northeast) tile allows a minecart on it to move either north or east from its present position. Therefore, if you want your minecart to move east along a straight piece of track, then return west using that same track, you would need to use EW tracks so that the cart could travel east initially, then return west over the same track. Excluding designs in which the cart will "jump" tracks via a drop or other ramp, tracks must be valid end to end to work for most looped or straight-track applications. A single east only track tile in your line of east-west tracks will cause any route using the track to fail the moment it tries to go the wrong way over that tile. Minecart tracks can be built in two ways: Engraved/carved or constructed. A given minecart track need not use engraved or constructed elements exclusively, as the two methods can be used interchangeably depending on the needs of a given section of track. The way the tracks are built is slightly different between the two, as explained below.

====Simple tracks====

'''Carved'''

A single-tile wide strip of natural stone can be designated to be [[Engraver|carved]] (with {{K|d}} {{k|T}}), which will create a straight two-way track. The creation of corners, crossings, and T-junctions is as simple as designating another strip of track that overlaps an existent or newly designated track. Engraved tracks are removed by [[smoothing]] the rock they're on, which results in a smooth floor (that can be re-engraved if necessary), or by building a [[floor]] on top and subsequently removing it. Dwarves can carve corner tracks in one pass by designating the track carving twice and canceling unwanted carvings (with {{K|d}} {{K|x}}). Tracks can be engraved in any natural floor tile, rough, smooth and even over engravings, providing an easy method to remove low-quality or undesired floor engravings. Once a track has been engraved, it's important to check the track directions for each tile in the route carefully to make sure no mistakes were made by yourself or the game's track engraving logic.

'''Constructed'''

Tracks can also be built as regular [[construction]]s (through {{K|b}} {{K|C}} {{K|T}}). This method is resource-expensive, since each track tile requires one stone, [[bar]], or [[block]] for construction, and time-consuming, since you can't designate strips longer than 10 tiles at a time. Corners, crossings, T-junctions, and ramps also have to be designated individually. However, it is usually the only way to build tracks above ground or on soil (barring the [[Obsidian farming|creation of obsidian]]). Constructed tracks are designated for removal like any regular construction; be aware that removing track ramps built on top of natural ones will also remove the original ramp, leaving a flat floor.

====Ramps====

'''Carved'''

The carving of natural ramps is a little more confusing: to carve a two-way track on a ramp (natural only, does not work on constructed ramps), you must designate the track '''starting on the ramp and one square beyond''' in the direction you want the track to go. For the side of the ramp square you want to head upward, there '''must''' be either a natural or constructed wall in the square next to it, otherwise the game assumes you are trying to carve it on the same level -- this can result in the track being carved underneath a door or other object. If you have accidentally done this, you can correct it by smoothing the ramp and constructing a single square of wall next to it, then re-carving the ramp correctly. (However, the wall must stay there permanently; removing it will disconnect the track.)

'''Constructed'''

When constructing track ramps, the stated direction should be the same as the connected tracks. For example, a track going up from West to East would require, starting from the West, a Track (EW), a Track/Ramp (EW) and a Wall behind the ramp, underneath the section of track above it. Incorrectly placed ramps result in minecarts ignoring the ramp and crashing into the supporting wall. They will not, however, display as unusable as when the supporting wall is missing.

'''Examples of ramps'''

A simple ramp would look like this:
{{diagram|spaces=yes|\
z +0 z +1
░░░░ ░░░░
═▲o ░▼═
░░░░ ░░░░
o : wall
}}

Carving track corners into ramps is rather unintuitive and complicated. Since engraving tracks always requires two tiles to connect in a straight line as input, you have to give two separate designations for a single job: a track bit from the ramp tile to the "below" direction and another one to the wall of the "upward" direction. If you wanted to change direction on a ramp from east to north:
{{diagram|spaces=yes|\
z +0 z +1
░░░░░ ░░░░░
░░░░░ ══╗░░
══▲░░ ░░▼░░
░░░░░ ░░░░░
}}

you would need to connect the ramp on z +0 both to the west and to the north by issuing two "carve track" commands, one selecting the ramp and the track tile to the west, and another connecting the ramp tile with the wall to the north. An engraver would then carve a NW track corner into the ramp, allowing carts to pass the corner correctly both going up and down. Such track corners are perfectly serviceable for guided carts, but moving down a route of several of them by pushed or ridden cart is problematic - ramps on corners behave very counter-intuitively, resulting in loss of speed when going down and diagonal movement when going up.

Moving to and from ramps (or between ramps "pointing" in different directions) causes some non-trivial adjustments to speed and even moving along the tiles at a fixed speed ''unrelated to the entry/exit velocity values'', because transitions to/from ramps are processed differently and are not to be "skipped". This affects compact track/ramp combinations (such as e.g. a simple 2x2 ramp spiral) most, and combined with bouncing often makes them work not in the way one could expect. {{cite forum|144328/5705102}}

{{anchor|Tracks}}

=== Hauling route ===
A hauling route is a list of directions describing how and under what conditions a minecart will move. The proper setting up of routes is essential for a working rail system. Routes, stops, departure conditions and stockpile links are managed from the {{k|h}}auling menu.

==== Route ====
A route defines the path a minecart will take along a track, as well as under what conditions it will move or stop moving. A route is made up of stops. Stops are precisely what they sound like, a position on the track at which you want a minecart to stop. A minecart track might use as little as a single stop for a looped track, which will serve as both a starting and stopping point for the cart, or it could contain many stops, perhaps to load supplies or wait for a bridge to be manually lowered, before reaching its destination or returning to its starting point. It is important to note that you only need to place stops on a route where you actually want the cart to stop and wait for some action to occur. They are not needed to help navigate the cart along the track beyond telling it where on the track to stop.

New routes are created with the {{k|h}}auling key. Existing ones can be removed (without confirmation) with the {{k|x}} key, and also {{k|n}}icknamed. Before operating, the route must have a {{k|v}}ehicle assigned to it (this can be done with either the route or a stop selected). Assigning a full minecart to a route may result in a slow hauling job if the contents are heavy.

==== Stops ====
Stops are the individual waypoints that make up a hauling route. A given stop consists of the location of a tile, as well as conditions describing when, where, and how a cart should be moved after being stopped at that tile. Stops can be created from within the {{k|h}}auling menu, by placing the cursor over a tile and hitting {{k|s}} while highlighting the route (or a stop within) you've already designated. A minecart will begin its route at the first stop created, and continue through each subsequent stop, being guided, pushed, or ridden from each stop to the next depending on the conditions specified. In many basic minecart applications, the cart will end up at the same stop it began at, though this is not always the case. It is important to note that hauling stop order is enforced, even if there is no track. A dwarf will drag the cart overland back to a skipped stop in the route's list if your tracks bypass it somehow.

Once a stop has been placed, it is given a default set of conditions under which to move the minecart if it is stopped there. Each new stop gets the same default conditions regardless of the track it is placed upon (e.g. guide the cart to the north). For this reason new stops might get marked by yellow exclamation marks ({{DFtext|!|#ff0}}) due to invalid directions. One important thing to note is that as you place additional stops, the display will show paths between the stops you have defined. However, this is '''not''' necessarily the actual route the minecart will take once the route is in operation. For example, if a route were defined with two stops at opposite ends of a track with many twists and turns, a line will be drawn directly between those stops to show the order in which they will be visited. These route lines may crisscross all over the tracks, but so long as the track is valid end to end, the cart will follow the track from one stop to the next, even across twists, turns, and z-level changes. Route stops, which are the steps that make up a route, should not be confused with physical Track Stops, described below.

===== Stockpile links =====
By placing the cursor on top of a stockpile and using {{k|s}}, you can create stockpile links while defining a hauling stop. Links can also be redefined by selecting them, placing the cursor over a different stockpile, and pressing {{k|p}}. The cart will then be filled by items present in its various linked stockpiles in preference to other items. Note that bins should be used with caution in stockpiles that are linked to minecarts. Bins cause problems when used with the "Desired Items" list in a stop's conditions. For example, if a minecart is set to accept only granite blocks, and to depart north when it is 100% full of granite blocks, it will not depart if any of those granite blocks are in bins, even if bins are also included in the desired items list. Two solutions to this problem exist as of v0.40.24. First, bins can be disallowed in stockpiles that are linked to stops. Alternatively, bins '''can''' be used in conjunction with minecarts provided that the minecart's departure conditions use only "any items" instead of "desired items." This option can be toggled in the advanced conditions menu for a stop, accessible via the {{key|C|}} key. The cart's contents can still be controlled by specifying what items are allowed in the linked stockpile.

===== Departure condition =====
Departure conditions involve setting conditions in which the minecart will leave on the route. Each condition includes:
# A departure mode (Guide, Ride or Push).
# An initial departure direction (NSEW). Note that this defines the initial direction of movement only. Even if a track includes many turns, as long as the initial movement direction is valid the cart will follow the minecart track thereafter.
# A timer, before which the departure condition cannot be met.
# Conditions on the amount of items in the cart.
Departure conditions are created with the {{k|n}} key. A new departure condition will read: "guide north immediately when empty of desired items". This condition can be changed between basic presets with {{k|c}}. "Advanced" mode ({{k|C}}) allows for more precise control over departure conditions: fine tuning the percentage from 0 to 100 in 25% steps ({{k|f}} and {{k|F}}), switching it being either the maximum or the minimum amount of items for the condition to be met ({{k|m}}), and whether the cart accepts all or only a specific set of items ({{k|l}}). Common to both screens are the departure mode ({{k|p}}, Push, Ride or Guide), {{k|d}}irection, and timer ({{k|t}} and {{k|T}}) options.

To have a cart only carry a specific set of items, the stop can be set to only carry "desired" items, opening the selection screen with the {{k|Enter}} key while having said stop condition selected, and toggling as desired, or it can simply be linked to a stockpile and set to depart once it is full of items from its linked stockpiles, regardless of type.

=== Track Stops ===
A Track Stop, not to be confused with a route stop, is an optional, single-tile construction which serves two purposes. First, it can be used to cancel a cart's momentum in order to slow or stop it as it passes over the Track Stop. This might be necessary if a cart were pushed down a series of ramps to its destination. Second, a Track Stop can cause a cart to automatically dump its contents as it passes over the Track Stop. Track Stops are constructed via {{k|b}} {{k|C}} {{k|S}}, and must be constructed atop an existing piece of track. If a Track Stop has been set to automatically dump a cart's contents, the cart will dump its contents in the direction indicated when it passes over the Track Stop. Depending on the friction settings chosen for the Track Stop, the cart might then stop after dumping, or it might continue on its route to another destination.

Track Stops are not mandatory; in fact, their main use is in automated rail systems. However, even in basic rail systems it can be useful to set a Track Stop to dump items: this saves time that dwarves would otherwise spend in removing items from the cart, time that is better spent driving the cart back to where it's needed. Dumping will occur even with a guided cart. '''Take care not to set Track Stops at a loading site to dump their contents''', or dwarves will never be able to fill the cart. It will dump any contents the moment they are loaded.

Counter-intuitive to their construction method, Track Stops are considered [[building]]s and must be removed by {{k|q}} {{k|x}}.
* See [[#More_on_Track_stop |More on Track Stops]]

=== Step-by-step tutorial ===

Let's construct a simple minecart route. This route will move stone blocks from an input stockpile to an output stockpile. We'll begin by creating the stockpiles:

[[File:minecart-example-1.png|Stockpiles designated.]]

The input stockpile is on the left; the output stockpile is on the right. We'll be moving blocks from left to right. Disable bins in both stockpiles, and set the input stockpile to accept only from links. Then make the stockpile take from the mason's workshop where the blocks are being produced.

Next, carve the track:

[[File:minecart-example-2.png|Track carving designation.]]

Note that the ends of the designation are uniquely shaped; this is automatic, and not anything you need to control. Now, wait for your engravers to come along and carve the track into the stone. (Your haulers will probably also fill up the input stockpile while you wait.)

In addition, while we're waiting for that to happen, we'll build an iron minecart in the forge.

[[File:minecart-example-3.png|Track carved.]]

When the track has been carved, it will look like the above (the track will be solid instead of flashing). Now, order a track stop to be constructed next to the output stockpile:

{|
| [[File:minecart-example-4.png|Track stop designation.]]
| [[File:minecart-example-5.png|Select dumping direction.]]
|}

You must press {{k|d}} three times to select the dumping direction ''before'' placing the track stop. We want our blocks to be dumped into the output stockpile east of the track stop. Then wait for a mechanic to come along and build the track stop.

[[File:minecart-example-6.png|Track stop constructed.]]

Now we'll define the actual ''route''. This is done in the {{k|h}}auling menu. Press {{k|r}} to begin defining a route. Next, move the cursor to the input end of the track, and then press {{k|s}} to define the first stop:

{|
| [[File:minecart-example-7.png|Stop 1 designation.]]
| [[File:minecart-example-8.png|Route definition, in progress.]]
|}

Move the cursor again, to the output end of the track, and press {{k|s}} again to define the second stop:

{|
| [[File:minecart-example-9.png|Stop 2 designation.]]
| [[File:minecart-example-10.png|Route definition, two stops.]]
|-
|
| [[File:minecart-example-11.png|Stops are not defined yet.]]
|}

There are several user interface features to note at this point. The stops have been positioned, but they haven't been ''defined'' yet, so there is a warning {{DFtext|!|#ff0}} symbol by each of them. In the lower right corner, we see what the {{DFtext|!|#ff0}} means. Also, note that the second stop is labeled in white, while the other two lines are grey. The white text is a selection indicator, and can be moved up and down by pressing {{k|+}}/{{k|-}}.

Next we need to define what our stops do. We want the minecart to be filled with blocks at the first stop, then travel to the second stop where it will dump its cargo, and then return. Press {{k|-}} to move the selection up to stop 1, and {{k|Enter}} to open it up. By default, the stop has three conditions:

[[File:minecart-example-12.png|Default stop definition.]]

We don't want any of these, so press {{k|x}} three times to delete them. This leaves us with a blank stop. Now we can add the conditions we actually want. Press {{k|n}} to begin adding the first condition, then {{k|d}} twice to change the direction from north to east. Then press {{k|c}} to change the condition from empty to full. This will instruct the minecart to be guided east when full of desired items.

To set the desired items, we create a stockpile link. Press {{k|s}}, then move the cursor to the input stockpile, then press {{k|p}} to select that stockpile. Now press {{k|Enter}}; this opens up a selection screen that resembles the stockpile customization screen. Move down to Blocks, {{k|e}}nable them, then (if you wish) restrict it to stone blocks.

When you've done all that, stop 1 should look like this:

[[File:minecart-example-13.png|Stop 1, defined.]]

Stop 2 is much simpler. All we need to do is have the minecart return to the input stop. So, make a condition and change the direction:

[[File:minecart-example-14.png|Stop 2, defined.]]

Finally, we just have to assign our minecart. Go back to the route definition screen, and press {{k|v}}. Select the minecart, and press {{k|Enter}}.

Now we've got everything set up:

[[File:minecart-example-15.png|Route, fully defined.]]

The V is red because the minecart hasn't been moved onto the track yet. Some dwarf will have to haul it from the forge to the first stop, by hand; this will take a while, especially if the forge is far away.

Once the minecart is in place, dwarves should fill it with blocks from the input stockpile, which will in turn be filled with blocks from the workshop where your mason has been toiling dutifully. When the minecart is full, the blocks will be dumped into the 1x1 stockpile on the right. Automatic quantum dumping!

=== Troubleshooting ===

Because of the complexity of the system, all but the most careful and experienced minecart users will encounter issues. Most route issues can be diagnosed and fixed from the {{k|h}}auling menu.

'''Symptom:''' {{DFtext|! Set dir/connect track|6:1}} message appears to the right of one or more stops

'''Possible Causes:'''
* In basic terms, the game checks if there is a valid path for a cart along the rails to reach the next stop in the route, and whether a dwarf ''guiding'' a cart would be able to find a path to the destination without carrying the cart. This warning pops up if the cart can't find a valid path based upon guided carts.
** If your cart path relies upon advanced tricks like deliberate falling into pits or ignoring floor types, even a path designed entirely as you intended will still trigger the yellow warning. (But double-check to make sure it's fine...)
* The departure direction of the stop might be invalid. Edit the stop using {{k|Enter}} and press{{k|d}} until it is pointing in a valid direction.
* The track stop might not be built on top of a track. The track stop must be deconstructed to remedy this issue.
* Your track might not be built correctly. Make sure all connected tracks between destinations are not one-way tracks.
** This can be especially confusing with ramps. To carve a two-way track on a (natural) ramp, you must designate the ramp and one square beyond in the direction you want the track to go.
** Ramps '''must''' have a solid block on the side opposite to the track, or they will neither work nor be marked as "unusable". The solid block can be natural or constructed.
* The desired/kept items might not be configured correctly.

'''Symptom:''' The status '''0% V''' always appears to the right of one stop.

'''Possible Causes:'''
* The stop may not be set to take from a stockpile. Edit the Stop using {{k|Enter}} and make sure you see a message like "Take from Stockpile #1".
* The take conditions must correspond with the contents of the stockpile.
* The track stop may be set to dump. A track stop set to dump cannot be filled. You must either set the stop to a time-based departure or deconstruct the track stop and rebuild it without dumping. (Alternatively, with [[DFHack]] you can modify "Dump on arrival" to "No" using the {{key|q}} menu without rebuilding the stop.)
* Make sure the minecart itself has not been designated to be dumped (such as when using mass-dump).

'''Symptom:''' Dwarves fill the minecart properly, but will not move it thereafter.

'''Possible Causes:'''
* The minecart may contain items which are not included in its current stop's desired items. Check inside the minecart using the {{key|k}} and {{key|z}} keys and ensure that all items in the cart are desired items.
* The minecart may contain desired items in bins. Minecarts seem to have problems realizing that they are in fact full of desired items if some of those items are in bins, even if bins are also among the desired items for that stop. '''This cannot be solved by adding the appropriate bins to the stop's desired items.''' Either disallow bins in stockpiles you intend to load minecarts from, or set the departure conditions to rely only on percentage of total load rather than percentage of desired items using the advanced conditions menu ({{key|C}} key).

'''Symptom:''' Dwarves repeatedly attempt to load the minecart, but no items are ever loaded into it.

'''Possible Causes:'''
* This can be caused by using a Track Stop with autodumping enabled at a loading site. Every time a dwarf places an item into a cart resting on such a track stop, the item will be immediately dumped, causing unlimited, useless cart loading jobs. Autodumping Track Stops should never be used at a loading site.

'''Symptom:''' A dwarf picks up the minecart and carries it to its destination.
* See [[#Quirks|Quirks]]

=== Danger ===
Minecarts are not without <strike>danger</strike> [[fun]]. Although designating a track automatically sets the [[traffic]] designation to low, dwarves ''may'' still walk on them, and [[creature]]s ignore traffic designations altogether. If an unlucky dwarf or creature fails to [[dodger|dodge]] a minecart, they can be injured. Most of this danger can be avoided by setting the minecart {{k|h}}auling commands to guide instead of push or ride (dwarves guiding minecarts will ignore traffic restrictions), as well as by [[pasture|pasturing]] domestic animals and preventing the access of other creatures to the tracks. Note that removing the track doesn't reset that tile back to normal traffic priority, so you may wish to manually clean up traffic designation afterward. Also note that bridges that are used as tracks don't have their traffic priority changed automatically (since they're just normal bridges), which could cause dwarves to pathfind normally through dangerous minecart entrances in your fort's walls if you're not careful.

The only <s>fool</s>''dwarf''-proof method is to make the tracks inaccessible. There are several ways to create a track which works for minecarts but doesn't allow creature-traversal; the simplest is perhaps building a [[statue]] on the tracks. Other options include adding single-tile holes (minecarts moving at reasonable speed will jump the gap), vertical drops, minecart-triggered doors, small pools of liquid (4/7 water or 2/7 magma), and hostile creatures overlooking the tracks. For safety, both ends of the track should be isolated, making the dangerous center sections completely inaccessible (though maintenance access can be provided by a locked door).

Danger does not always involve living victims: careless route designation can also result in minecarts careening off tracks or colliding with each other. If this occurs, the [[item]]s may be scattered; this can cause even more hauling jobs than the minecart aimed to eliminate. Even <s>better</s> worse, scattered items, especially [[weapon]]s, can injure passing [[dwarf|dwarves]] or other [[creature]]s; in the words of Toady One the Great, "Accidental grapeshotting of the dining room should be possible now."

Of course, the danger of using minecarts means they can also be [[Trap_design#Minecarts|used as weapons]] by imaginative players.

== Advanced usage and automation ==
Minecart-specific effects are implemented via track stops, rollers and [[pressure plate]]s with "track" condition set. Since all three are considered [[building]]s, they can't be built on the same square (however convenient track stop + pressure plate would be) nor a simple ramp, and are removed by {{k|q}} {{k|x}}.

=== More on Track stop ===
Track stops are constructions that allow further automation of minecart systems via adjustable features such as braking by friction and automatic dumping of contents. They can be built from logs, bars and blocks through {{K|b}} {{K|C}} {{K|S}}; friction amount, dumping toggle and dumping direction must be set '''before''' construction, and these settings can be neither changed nor seen thereafter; however, track stops can be linked to [[pressure plate]]s or [[lever]]s to toggle friction and dumping On or Off (trigger state is inverted: switch On = track stop Off).

If a [[stockpile]] is placed on the tile that a track stop is set to dump to, it can act as a [[Exploit#Quantum_stockpiles|quantum stockpile]] and any items dumped from a minecart that match the storage settings of the stockpile will remain there and accumulate. Normally trackstops are built on top of existing track to operate on moving minecarts, but they can also be used without tracks to create [[Exploit#The_Minecart_Stop|automatic quantum stockpiles]] (see also [[#Step-by-step_tutorial|step-by-step tutorial]]). It is not always desirable to collect ALL of certain items into one quantum stockpile, such as when distributing a material to multiple separate industries. You can link your quantum stockpile to various other stockpiles, ensuring that your dwarves will keep them supplied as necessary. Because quantum stockpiles never fill up like regular stockpiles, it may be a good idea to add a switch to turn them off.

Items dumped from a minecart at a track stop (or dumped by any other means) into open space fall through z-levels until they land on a solid surface. Items falling onto a designated [[stockpile]] will automatically be considered part of that stockpile, even if the stockpile is set to disallow those items (they will, however, be automatically moved to a more appropriate stockpile, if available). Items falling on top of a minecart will '''not''' fall "inside" the minecart. Use with caution; dwarves have fragile skulls.{{bug|5945}}

=== Automated propulsion ===
==== Roller ====
{{Main|Roller}}

A '''roller''' is a [[power]]ed [[machine component]] for the automated propulsion of minecarts. They are built over the top of existing tracks with {{K|b|M|r}}, requiring a [[mechanic]], ''(length/4)+1'' [[mechanism]]s and a [[rope]]. Rollers may also be placed directly on ramps to help pull carts up Z levels. Rollers are very useful to maintain a cart's momentum along long routes, to get them to climb Z-levels without dwarfpower involved, and to get them to reach speeds unattainable by guiding dwarves. These devices are variable-length (1-10), variable-direction and variable-speed ([[Minecart#Numbers_behind_the_scene|see below]]), all traits that can be set at construction time; a roller uses two units of power per tile it is long.

Single-tile rollers transfer power in all four cardinal directions, while other rollers generally only transfer power perpendicular to their activity direction. Longer rollers can also transfer power along their activity direction if built in the correct order, although this can be hard to accomplish and is easily broken. Rollers cannot be powered from above.

Rollers have great acceleration and capped speed. Carts going faster than the roller are unaffected. If a cart moves across an active roller in the direction the roller works and moves slower than the roller's specified speed, the cart will be set to the roller's speed. A cart going against a roller's movement direction will be sent back the way it came (once again at the roller's speed), unless it was moving extremely fast: speed increment of 100000 allows to reverse carts from the full "highest" (50000) speed roller to full "highest" speed back, but ramps can accelerate a cart beyond this. {{cite forum|144328/5702453}}
A cart crossing over a roller perpendicular to its current movement direction will gain the roller's amount of speed in the perpendicular direction without directly changing its forward motion. Without an adjacent wall to constrict its movement, this will typically send a cart off the rails on a diagonal path, completely unable to follow any tracks until it collides with a wall or is otherwise brought to rest. However, if the roller is placed over a track turn and pushes ''from'' the direction of that turn's track, the turn affects carts ''after'' the roller, so they will be forced into the turn rather than derailed in a diagonal direction. {{cite forum|144328/5702453}}

{{diagram|spaces=yes|\
tracks: full:
║ ║
═╗═ ═╢═
║ ║

╢ : roller pushing from W to E
}}
If the roller is powered, carts from ''all'' directions (unless too fast) exit S, because speed imparted by the roller forces carts toward E and ''then'' into the turn.
If not powered, carts from W and N exit S, carts from E and S exit W. Carts above derail speed will ignore the turn, of course.

{{diagram|spaces=yes|\
║ ║
═╗═ ═╟═
║ ║

╟ : Roller pushing from E to W
}}
Carts from the E or W: exit W.
Carts from N: derailed diagonally, exit SW.
Carts from S: derailed diagonally, exit NW.

Rollers affects carts on a track - if placed on a floor or ramp without any tracks, they are ignored. Depowered rollers are also ignored, friction is determined by the tiles underneath.

Because of their one-way nature, rollers are unsuitable for most two-way minecart tracks (unless you set gears toggling roller A->B off while toggling A<-B rollers on). However, a minecart set to be ''guided'' is not affected by rollers at all{{cite forum|109460/3286235}} — this allows a one-way track to be used in both directions. In addition, unpowered rollers do not affect minecarts.

Care must be taken in [[glacier]]s and other extremely cold [[biome]]s, since rollers (and the machinery used to power them) will not operate when constructed on natural [[ice]] floors.

==== Impulse ramps ====
Carts can be given momentum without rollers or changing z-level through a phenomenon called "impulse ramps". A track ramp which is connected both to a wall and to a floor will ''always'' accelerate a cart towards the connected floor tile, no matter where the cart enters the tile from. This means carts can be accelerated as though dropping z-levels, even if the cart doesn't actually change z-level at all. If a track ramp faces three directions such as ╩, then two of those directions need to be facing walls for the cart to be accelerated towards the remaining direction.

Example of straight impulse acceleration:

{{diagram|spaces=yes|\
▒▒▒▒▒▒▒▒▒▒ ▒▒▒▒▒▒▒▒▒▒
═▲▲▲▲▲▲▲▲▲▲═ ═╚╚╚╚╚╚╚╚╚╚═
▒ : Wall
═ : Normal track
▲/╚ : N/E Track/Ramp
}}

If a cart enters from the left, it will speed up on every track/ramp and exit to the right going very very fast - more than one tile every step. If it enters from the right then it will bounce back impulsed by the ramp if it's going slow enough.

As another oddity, carts coming from ramps will in some cases "teleport" through most of the next tile. This is called the "checkpoint effect", and is explained in detail in the Physics section, below. This negates the deceleration of the next tile if it is a ramp "angled" in a different direction. You can just make an upward spiral alternating impulse ramps and regular upward ramps. It takes no power, is quick and cheap to build, requiring only channeling and track carving, and the cart goes up fast, but not so fast that it launches its contents.

Example of an impulse elevator:

{{diagram|spaces=yes|\
z +0 z +1 z +2 z +3
░░░░░ ░░░░░ ░░░░░ ░░░░░
░╔░░░ ░▼╚╗░ ░░▼▼░ ░░░░░
░╝░░░ ░▼░░░ ░░░╔░ ░░░▼░
░▼▼░░ ░░░░░ ░░░╝░ ░╚╗▼░
░░░░░ ░░░░░ ░░░░░ ░░░░░

░ : Wall
╔,╚,╗,╝ : Track/Ramp
▼ : Down Ramp (empty space)
}}

Note that this impulse elevator, due to the checkpoint effect and upward curved ramp effect, will not actually result in carts traveling straight up the ramp. They will lose speed, bounce off a ramp, then be accelerated back into the spiral after a 9-turn delay on both tiles on the floor where they are stopped. This is because the checkpoint effect allows carts to travel up the ramps in a single turn, but also prevents the impulse ramps from adding acceleration unless the cart is slowed to staying on the ramp for more than one turn. Initial acceleration will carry the cart up a variable number of floors before this effect occurs, but this bouncing back and forth will occur every 5 z-levels after the first time the cart stops. When the cart ''is'' traveling upwards, it will pass every tile at a rate of one tile per turn regardless of its actual speed, due to the checkpoint effect. In tracks with only a single cart, this is negligible, but when multiple carts are on the same track (such as when you place multiple carts on a magma cart lift) this can cause collisions which derail carts or cause other unexpected or undesired behaviors.

The following impulse ramp (while larger) should alleviate these problems by using a straight ramp to go upwards, preceded by an impulse ramp to exploit the checkpoint effect and negate up ramp costs. Corners still decelerate carts, so the cart will tend towards a velocity of 72k, which is derail speed. Derail speed breaks (see Controlling Speed, below) may be necessary at the top.

{{diagram|spaces=yes|\
z +0 z +1 z +2 z +3
░░░░░░ ░░░░░░ ░░░░░░ ░░░░░░
░░░░░░ ░╔╔═░░ ░░▼▼╗░ ░░░░░░
░║░░░░ ░▼░░░░ ░░░░╗░ ░░░░▼░
░╚░░░░ ░▼░░░░ ░░░░║░ ░░░░▼░
░╚▼▼░░ ░░░░░░ ░░░░░░ ░░═╝╝░
░░░░░░ ░░░░░░ ░░░░░░ ░░░░░░

░ : Wall
║,═,╔,╚,╗,╝ : Track/Ramp
▼ : Down Ramp (empty space)
}}

Also, if you want to have a cart following a below-derail speed, the following track works well:
{{diagram|spaces=yes|\
z +0 z +1 z +2 z +3
░░░░░ ░░░░░ ░░░░░ ░░░░░
░░░░░ ░══░░ ░▼▼║░ ░░░▼░
░║░░░ ░▼░░░ ░░░║░ ░░░▼░
░║▼▼░ ░▼░░░ ░░░░░ ░░══░
░░░░░ ░░░░░ ░░░░░ ░░░░░

░ : Wall
║,═ : Track/Ramp
▼ : Down Ramp (empty space)
}}
In this elevator, the cart collides with the walls in the corners, but then realigns on the ramp, picks up speed, checkpoints through the next ramp, and slams into the next wall. It is slower (10 ticks per floor) but produces reliable speeds, and will exit the impulse elevator at little more than push speeds.

A sort of opposite effect to impulse ramps also exists: ramps lacking the proper "up" and "down" connections are treated as flat track, even if they actually go up or down z-levels. This allows building "anti-impulse" slopes consisting entirely of ramps only connected up, which a minecart can travel up forty levels and more, needing no more than a single push.

=== Controlling traffic ===

==== Switching ====

As constructions or tile features, [[door]]s and other furniture can be built on tracks. A [[door]] or [[floodgate]] can be turned on or off by a [[lever]], effectively controlling the flow of automated minecarts. This may be <s>dangerous</s> [[fun]], however.
{{diagram|spaces=yes|\
->
A ════┤≡════ B
┤ : roller pushing to East
≡ : door
}}
The roller pushes the cart east, but until the "departure condition" is fulfilled, the door remains closed and blocks the path.

[[Bridge]]s can also act as tracks, but only if they're lowered or not retracted. This property can enable levers to turn tracks on and off. However, care should be taken to ensure that such bridges are never operated while a cart is on top of them, as the cart will be flung off the track. It's worth noting that it's often faster, and cheaper, to construct large bridges than long sections of constructed track.

A powered track switch can be constructed by building an "inverted" corner as illustrated below.
{{diagram|spaces=yes|\
B B
║ -> ║
║ ║
════╚═══ ════├════
A C A C
├ : roller pushing to West.
}}

If the cart is pushed East from the stop at 'A' while the roller is activated, it will arrive at 'B'. If the roller is not running, it will arrive at 'C'. The switch works by the roller first reversing the incoming cart's movement and the cart ''then'' following the track corner.

This switch is very reliable, reacts instantly to on/off signals, and carts of any speed can be switched by this design, although very fast carts will require rollers that are several tiles long, up to three. The requirement for power can be inconvenient or impractical. Non-powered solutions may use controlled derailment, or a connecting bridge.
{{diagram|spaces=yes|\
B ╥
║
║
╞════╝ ════╡
A D C
}}
Here the track between A and C is not continuous. The only continuous track is A->B, with a corner (not a T section). Fast moving carts will tend to derail at D and rejoin the track to C. Placing a door at D will prevent the derailment, so the cart continues to B. The door is operated by mechanisms elsewhere (typically, a lever, but some fun can be had with pressure plates).

Since it depends on derailing, this switch requires a very fast cart, faster than what can be achieved with rollers alone. To gain sufficient speed, a cart must be accelerated further, usually by descending several levels or through impulse ramps. The high speed makes the cart much more dangerous and harder to control.

If carts are moving too slowly to derail at the corner, a retractable bridge may be used as a connector between A and C.
{{diagram|spaces=yes|\
B╥
║
║
A╞════bbb════╡C
}}
The bridge must overlap the corner. Bridges behave like a track crossing, allowing carts to pass in a straight line. When retracted, the corner reappears, so the carts will continue to B. Bridges take 100 steps to react to a signal, necessitating rather long "lead times" when switching tracks via bridge.

As mentioned above, special care must be taken to make sure the bridge doesn't change state while the cart is passing over it. Retracting bridges will throw the cart, causing it to stop dead. Raising bridges can even crush the cart.

==== Controlling Speed ====


Minecarts can reach extremely high speeds, especially when descending multiple Z-levels. A minecart will derail at a track corner if its speed exceeds 0.5 t/st (tiles per step), '''unless''' the route in the direction of travel is blocked:

Will derail at > 0.5 t/st:

{{diagram|spaces=yes|\
in ══╗ -> derailing
║
out
}}

Will not derail at > 0.5 t/st:
{{diagram|spaces=yes|\
in ══╗O
║
out

O : wall/column.
}}

This behavior can be used to build a "speed limiter", that will ensure that when a minecart exits it is traveling below derail speed:
{{diagram|spaces=yes|\
░░░░ ░░░░░ ░░░░░
in ═╔═╗░ ░╔S╗░ ░╔S╗░
out ═╬═╝░ out ═╗═╝░ out ═╗═╝░
░╚S╝░ ░╚═╝═ in ░╚S╝░
░░░░░ ░░░░ ║░░░
in
░ : wall
S : Track Stop (High Friction or lower)
}}
If the minecart is traveling below derailment speed, it will not be affected; if above, will be slowed down and checked again. Granted, you could do the same just with track turns, but it may take a lot of turns and time.

Since all the derailings, bounces and ramps can impart a sideway component of speed small enough to start visible drift many tiles away (say, [[Fun|in the middle of a bridge]]), track turns have one more use: forcing the carts to move strictly along the grid directions. Carts passing a turn below derailing speed convert one component of velocity into another, thus eliminating the drift.

=== Loading liquids ===
[[Water]] and [[magma]] can also be loaded into minecarts by submerging them to a depth of at least 6/7 while standing still or moving at speeds of at most 10000. Loading fluids onto minecarts can be difficult because the added friction provided by fluids can stop a cart in a submerged tile. Curiously, filling a minecart with magma does not injure a dwarf ''riding'' it. A minecart will hold enough fluid to increase the depth of a single tile by 2. This amount is listed as 833 units, which weigh 459Γ (water) or 999Γ (magma). An iron or steel cart filled with magma weighs 1313Γ, while an adamantine cart filled with magma weighs 1007Γ. Since you need a minecart above the liquid's level, possible arrangements may include pressure-activated sluices, rollers (with magma-safe chains for magma), pouring from above to "submerge" it briefly on the same level and drain excess away (dig deeper and leave a vaporizer, though if you could have power for rollers, may as well use a pump) and exploits with ramps (not necessarily impulse ramps, "same height" passing dip does it).
The liquids can be dumped by a constructed track stop.

== Quirks ==
This little quirk concerns dwarf-managed minecarts. If a track which was previously open becomes blocked (ex. flipping a switch connected to a floodgate you've built on the track to raise it) and the conditions for departure are met, instead of refusing to ride/guide the minecart or ride/guide it until it reaches the obstacle, the dwarf will pick up the minecart off the tracks and haul it to its scheduled destination on foot. If the distance is long enough and the weight of the cart heavy enough (due to being filled with heavy items such as stones), the dwarf may drop the cart because of fatigue/hunger/thirst before reaching the destination. This will cancel that vehicle setting job and make another dwarf come by and attempt to haul the cart to the nearest appropriate stockpile where another dwarf will pick up the cart and attempt to haul it to its initial stop. If the stockpile is far enough from initial stop, this second dwarf who is attempting to place the minecart on its tracks may also drop the minecart out of fatigue/hunger/thirst creating a loop that will go on until a dwarf with enough endurance manages to place the minecart where it belongs.

In fact, it seems dwarves are more than happy to attempt to carry a minecart from one stop to another even if just waiting until the track is open again would be the more sane option.

Dwarves will also carry a minecart to its next stop if the direction specified is incorrect (or invalid). This can often occur when using the default departure settings and forgetting to set the direction of each condition.

Dwarves can admire buildings while riding mine carts. Dwarves will not fall asleep during a ride (at least not from being drowsy). If riding on a continuous powered track loop, the dwarf will die of dehydration/starvation as they can not jump off to get sustenance{{cite forum|109460/3377228}}. Dwarves riding in submerged minecarts will gain experience in [[swimming]].{{cite forum|129889}}

Tracks block wagon access to trade depots, unless they're on a ramp. [[Bridge]]s can also be used, as they function as tracks but do not block wagons.

== Physics ==


Minecart physics depend greatly on the departure mode set in the route stop conditions.

When set to "Push" or "Ride", minecarts will move according to the regular laws of momentum, gaining speed when going downhill, losing it slowly due to friction when on a flat plane, and more quickly when going uphill. In these modes, minecarts will move in a straight line until they either are brought to a stop by friction or an obstacle, or until they encounter a turn. A minecart will roll straight past "blocked" ends of T-junctions or track ends, they have no power to restrict a cart's movement. The cart's behavior is largely independent of the weight of its contents (including fluids and dwarves): heavily loaded carts gain more momentum when accelerating, but this only plays a role in collisions: a heavy cart gains just as much speed and is as easy to stop as a light one. In either case, dwarves can not push nor ride an unpowered cart up a ramp, bouncing back the direction it came. At best, this is a waste of time; at worst, it will give your cart-pushing dwarf a [[fun|fun surprise]]. To solve this, the player can either use Rollers (see below) or set the cart to be Guided.

The difference between "Push" and "Ride" is whether the dwarf will go along with the cart or not.
{{DFtext|Push}}: the dwarf will give the cart an initial push, not enough to go up a ramp, but enough to go some way along flat track, and the dwarf will remain at the first stop, ready for a new job.
{{DFtext|Ride}}: the dwarf will give the cart the same initial push and then hop aboard the cart riding with it to the next stop.
{{DFtext|Guide}}: minecarts seem to ignore all laws of physics. That is:
*Ignore the weight of any and all items inside. Therefore:
**Move at the speed of the dwarf that is guiding them. It is thus recommended to pick the most [[attribute#Agility|agile]] of your dwarves for cart-guiding tasks.
*Ignore working rollers.
*Will ''not'' collide with other guided carts even when a full frontal collision would be expected.
*Will go up ramps like nobody's business.
This is therefore the recommended method of transport for simple non-powered rail systems, despite it diverting a dwarf from other, potentially more important tasks.

Some samples with behavior:
{{diagram|spaces=yes|\
A <-> B A <-> C A <-> B
B B B
║ ║ ║
A══╝ A══╩══C A══╬╗
You can only go A->B ╚╝
Works when the cart Works
is in Guide mode.
}}
In the second example above, a cart "pushed" from B will go over the junction and roll off into the unknown south.

=== Numbers behind the scene ===

According to early research by '''expwnent'''{{cite forum|112831/3536975}}:

The minecart has 3 variables for velocity. Velocity can be thought of as tiles per 100000 ticks, so a velocity of one hundred thousand means a cart travels one tile per tick. By going down a large number of ramps, a maximum velocity of 270,000 can be reached, which presents the limit for most practical applications. Short bursts of (much) higher speeds are possible through carefully planned collisions of high-speed carts {{cite forum|137557/5145499}}. (See [[#Perfectly Elastic Collisions|Perfectly Elastic Collisions]].)

Every tick the cart adjusts sub-tile position units by the amount of their velocity, as well as adjusts velocity depending on current tile (speed is reduced by the "friction" of the tile, or accelerated if going "down" a ramp). On flat (non-ramp) tiles, the cart will move to the next tile when the sub-tile position goes either above 100,000 or below 0, (or several tiles if velocity is over 100,000,) and 100,000 is either added or subtracted to sub-tile position to restart the count to the next tile change.

Since most deceleration and acceleration is applied per step, with the notable exception of corners, a cart going at twice the speed of another one can cover about four times the distance in a straight line, but only twice the distance along a winding track with very many corners.

A push will teleport a cart to the middle of the next tile in one tick with 19990 speed (10 speed is lost due to track friction), while a roller will directly give a cart the roller's set speed and the cart starts accumulating distance from its standing position. When a cart leaves a ramp it will emerge after one tick at the very end of the next regular tile.

Friction of tiles:
{| class="wikitable"
|-
! Tile
! Friction
! Comment
|-
| Tracks
| 10
|-
| Ground/Floor
| 200
|-
| Unusable ramp
| 10
|-
| Upwards ramp
| 4910 (10+4900)
|-
| Downwards ramp
| -4890 (10-4900)
|-
| Roller
| ±100000 (but capped by the set speed)
|-
| Corner track
| 10
| Speed reduced by 1000 upon leaving the corner tile
|-
| Track stop (highest)
| 50000
|-
| Track stop (high)
| 10000
|-
| Track stop (medium)
| 500
|-
| Track stop (low)
| 50
|-
| Track stop (lowest)
| 10
|-
| Water 1-6
| Additional (WaterLevel - 1) * 100
| rowspan="2" | [[#Skipping|See Skipping]]
|-
| Magma 1-6
| Additional (WaterLevel - 1) * 500
|-
| Empty space
| 0
|}

Water of depth 7/7 provides a friction of about 10000 per step, as does maximum-depth magma. This higher friction may not apply to very slow-moving carts.

Impulse sources:
{| class="wikitable"
|-
! Feature
! Speed
|-
| Push
| 20000
|-
| Roller lowest
| 10000
|-
| Roller low
| 20000
|-
| Roller medium
| 30000
|-
| Roller high
| 40000
|-
| Roller Highest
| 50000
|-
|}

Note, again, that nearly all of these values are applied ''per tick'', rather than ''per tile''. The exceptions are curves, which is 1k deceleration per direction change at the half-way point of the tile, and rollers, which ''set'' the speed every tick. This makes rollers particularly useful in high-deceleration situations, such as underwater, but require that ''nearly every tile'' in such high-deceleration situations have a roller.

A cart heading up a ramp can experience deceleration on multiple ticks, (and stays on the tile more ticks the slower it is going, resulting in greater deceleration,) and as such, a cart leaving a "Highest Speed" roller with 50k velocity will not be able to climb 10 consecutive straight ramps, since they are ''not'' "5k deceleration each". In fact, the first ramp not on a roller will be -15k velocity, and, depending slightly upon other factors of "remainder" x position, the second may completely cancel forward momentum, and send it rolling back down, where it will bounce off the roller repeatedly. Using rollers to power carts up ramps reliably requires rollers every other un-rollered ramp. Fortunately, rollers can be built upon ramps, themselves, which allows for rollers to only need to be built every other floor. (Exploiting the [[#Checkpoint Effect|checkpoint effect]] can allow one to bypass this requirement.)

=== Sub-tile Positions and Velocity ===
Carts store six values that are unique to them. Three sub-tile position values, and three velocity values. (X, Y, and Z.)

Note that the Z position and velocity only matter when a cart is in flight. (See [[#Falling|Falling]] and [[#Cart Jumps|Cart Jumps]].)

Each non-ramp tile is functionally composed of a value between 0 and 100,000, with a "centered" cart sitting at the 50,000 point in all three directions. When a cart has velocity, it is added or subtracted from the current position every tick, and then a friction force is applied to the cart.

In essence, every sub-tile position unit is a decimal value of a tile, 0.000001 tiles, in a game that largely prefers integer values.

When carts move beyond the maximum or minimum value of a tile, they physically move a tile on the map, and start at the far end of the sub-tile position the next tile. (I.E., traveling West, a cart that starts a tick at 15,000 X sub-tile position and has an X velocity of -20,000 would move to -5000 X sub-tile position, which is out of bounds for that tile. As such, it will travel one tile West, and start the next tick at 95,000 X sub-tile position. It will also lose 10 velocity in that tick due to friction with the track if it is on a track, or 100 velocity if it is on regular ground, or no velocity if it is airborne.)

Ramp tiles are longer, approximately 144,000 in the direction where it "slants downward", (to approximate a 45 degree slope, it is square root of two times longer,) and centered at 72,000. Because of this, a cart with no velocity dropped from a hatch will land at the center of a tile, at position 72,000, and 72,000, and will start rolling in the ramp's "downward" direction, picking up the ramp's acceleration (4890 per tick in the direction of the ramp's "downward" direction) every single tick, then moving that sub-tile amount every tick. (This results in a cart that takes 5 ticks of acceleration to leave its ramp - 6 ticks overall - and to leave the ramp with about 23k velocity, slightly more than a push.) When it enters another ramp ''facing the same direction downwards'', a cart will start at the 0 or 144,000 position, and have twice as far to travel. This means that if a cart enters a ramp from the side, it will gain twice the momentum of simply starting at the midpoint of a ramp.

Note that passing from one direction of ramp to another or to flat terrain causes unintuitive behavior, "teleporting" to the midpoint of another tile in what is called the "[[#Checkpoint Effect|checkpoint effect]]".

Note, however, that sub-tile positions are carried over from tile-to-tile. This separate tracking of velocity and position between X and Y can lead to problems with diagonal motion:

{{diagram|spaces=yes|\
z0 z-1
▒║▒ ▒▒▒
═▼═ ▒╬▒
▒ ▒ ▒║▒
▒ : Wall
═, ║ : Track
╬ : Track and Ramp
}}

If a cart is passing West-to-East over this setup, the valid ramp to the South will apply "Southward" acceleration to the cart (-Y velocity) as it passes through the ramp tile. Assuming it only spends one tick in that tile, it will still have gained about -5k Y velocity, which will still apply motion Southward. If the tracks continue straight for another 11 tiles, it will have accumulated enough Southward motion to try to move a tile South, even if all tracks are facing East-West.

'''Non-curving tracks do not correct this motion'''.

They don't "tip back over" without adjustments in the track. Any value of sideways motion on tracks larger than 990 will lead to a derailment. (Lower values will be nullified by friction before they are enough to lead to derailment, but there is currently no way to apply such a small amount of velocity.)

If the tile to the South is a wall at that point, it will be considered a collision with a wall that ''halts all motion''. If the tile is open, it will generate a diagonal track derailment that will send a cart flying until it strikes a wall, at which point it will not re-rail itself. In almost any circumstance, this is undesirable behavior.

The only way to appropriately deal with this is to either cancel out this behavior with an equal amount of acceleration in the opposite direction, or to take a curve.

Note, again, that sub-track position is saved in both directions, so when a cart approaches a curve, it will already have a shorter or longer distance past the curve when it makes the turn.

Curves are applied "halfway through" a tile. If a cart is moving East, and approaches a North-West track at 20k velocity, and friction is eliminated for the purposes of a cleaner demonstration, then when it enters the tile at sub-tile point 0 X, and 50k Y at the start of a tick, it will then move 20k East (+X) the next tick, and be at 20k X sub-tile position, and 50k Y sub-tile position. Next tick, it is at 40k X sub-tile position, and 50k Y sub-tile position. The next tick would take it to 60k X, but that's past the halfway point, so it stops at 50k, turns (and thus loses 1k velocity, but translates the rest from X-velocity to Y-velocity) and travels another 10k. It is now at 50k X sub-tile position, and 60k Y sub-tile position. Next tick, it travels at 19k velocity North, and so moves to 50k X sub-tile position, and 79k Y sub-tile position. Then in two more turns, it leaves to the North.

In the case of diagonal motion due to having velocities in X and Y at the same time, it is critical that the direction the cart is heading in reaches that halfway point in a curve before the cart leaves the track off its sideways velocity direction. If it does so, all sideways velocity is lost, as forwards velocity ''overwrites'' sideways velocity in a curve. If, in that example in the paragraph above, the cart entered at 0 X sub-tile position with 20k X velocity, and 40k Y sub-tile position and -1k Y sub-tile position, it would take that "curve" (or rather, redirection of velocity) on the third turn, while it is at 38k Y sub-tile position to start with, and then move to 47k Y sub-tile position at the end of that tick. It would then move to 56k Y sub-tile position in the following turn, and take 3 turns, rather than just 2, to clear the tile.

But, most importantly, it would be centered in the X sub-tile position, and with the negligible difference of an extra tick, all sideways velocity could be safely ignored.

There are two common ways to gain sideways velocity: Rollers facing perpendicular to the cart's travel path (which, as covered above, are almost always a bad idea, as it is easier to push ''against'' the travel direction of a cart into a curve, which redirects all velocity in the new direction,) and [[#Corner Ramp Derail|corner ramps]], and require a curved track to compensate for sideways velocity within a few tiles.

=== Track Direction Irrelevance ===
Carts that are traveling independently, (that is, not guided,) only care that tracks ''are'' on the tile, not which direction the tracks actually move. Tracks respect only curves (with two exits) and ramps.

This means, for example, that the following tracks, when a (non-guided) cart travels from West-to-East, are functionally identical in effect:

{{diagram|spaces=yes|\
A════════════B A╬║╚╔╣╩╦╠╥╨╞╡B
}}

This is because so far as the cart is concerned, only valid ramps and curves with two exits where there is no exit in the path they are traveling matters.

Hence, if a minecart encounters the end of the track or a T junction with no "exit" in its movement direction, it will simply leave the track and continue on its course in a straight line until it encounters an obstacle, slows to a stop, or encounters another track even if the tile at which it joins the new track instantly sends it around a corner.

In fact, in a track designed for pushes or rides, a "║", a "╦", a "╬", and a "╥" are ''only different in appearance'', and are ignored by an unguided cart, which will continue in its current direction, regardless of the track. For any purpose but guided tracks, ''only curves and ramps matter at all''.

Tracks like T-junctions, however, ''are'' respected by dwarves guiding carts, who will lift and carry carts if they cannot find a valid track to their destination, and can choose to follow any orthogonal direction at a four-way junction in much the same way as they normally pathfind. What this functionally means is that T and four-way junctions ''only guide dwarves hauling a cart, not carts, themselves''.

Carts only check for curves when they are halfway through a tile. When they get there, they look to see if their path has no exit. (That is, if it is traveling East, it checks if there is an East exit.) If there is, it ignores all other track directions, and keeps traveling. If there is not, it checks to see if there are only two exits to the track, and if one of those directions was the direction it "came from". (That is, if traveling West from the East, it checks if there is a valid exit to the West, and if not, if there is an East exit and EITHER a North or South exit.) If there is not, it ignores the track anyway, and keeps on traveling as though it were still on track.

If there is a curve the cart will respect, it checks for derailment. Carts derail at a speed whose exact number is currently unquantified, but is over 50k. Carts at this critical speed will then check for blockages of their forward path. If there is an obstacle to their path, which may be a wall or even furniture or buildings like a door or impassible workshop tile, they will not derail and respect the curve, anyway. Derailing carts do not "[[#Cart Jumps|jump]]" unless they hit completely untracked tile or an invalid ramp, but simply ignore the layout of the tracks entirely. With invalid ramps, this means not respecting the ramp, and likely results in collision with a wall, zeroing of all velocity, and a cart that requires manual retrieval.

If the cart is traveling at a speed that will not derail, or is forced to turn by a supporting wall, it will subtract 1000 from the "forwards" velocity of the cart, and redirect all forward velocity to the direction of the curve. This change in the direction of velocity ''overwrites'' any "diagonal" velocity, which can prevent diagonal velocity derailments, but any perpendicular velocity is not preserved, and is instead discarded.

=== Valid and Invalid Ramps ===
Ramps are functionally defined for cart purposes as being a tile which exerts an acceleration force upon its "downward slope", and which allows connection to tracks a z-level above or below. This downward slope requires a cart to have one ''and exactly one'' carved exit to the tile that is the "bottom" of the ramp. Ramps accelerate carts in this "downward" direction (possibly leading to [[#Corner Ramp Derail|diagonal movement]]), and the deceleration of an "uphill" ramp is actually just the acceleration being applied against the direction of a cart's movement.

This is where players can find an exploit in the behavior of ramps - if there are ''two'' "downhill" exits to a ramp (such as a "T junction" on a ramp where only one exit faces a wall), then the ramp provides no acceleration ''or'' deceleration, allowing carts to travel up ramps without any loss of momentum except for the standard "flat track" deceleration, because as far as the cart is concerned, the track ''is'' flat. (A T junction is also not a curve, so the track is considered flat and straight no matter what direction the cart is traveling.)

Similar effects can be achieved when there are ''no'' "downhill" exits to a ramp. This may be the case if you have, for example, an East-West track with a one-tile channel with a ramp in it. The cart will travel through the "dip" with no change in velocity. It can also be the case if you abuse the [[#Track Direction Irrelevance|Track Direction Irrelevance]], and set only exits ''up'' the ramp, and none leading ''down'' the ramp. For example, if a cart is traveling from West to East up a slope, only carving East exits on each tile of ramp will make the cart travel up the ramp, and then recognize the tile it is on as being a "flat" tile, thus ignoring any deceleration from traveling uphill.

Note that this effect only reliably occurs at below-derail speeds as the cart will treat the ramp as an invitation for a ramp jump otherwise. (This almost always results in a collision with a wall that will stop forward progress.)

=== Falling ===
When falling, a minecart appears to cause no damage upon collision, possibly to allow cart "stacking" across Z-levels.{{cite devlog|2012|04|06}} A dwarf riding in a minecart that is dropped multiple z-levels suffers normal fall damage. Minecarts can fall through up/down stairs.

While airborne, carts do not feel the effects of friction in any horizontal direction, and will continue until they strike an obstacle. Carts that land on tracks instantly re-rail themselves regardless of track directionality.

Falling carts accelerate similarly to the way that a ramp will accelerate a cart in a special z-only velocity that only applies to airborne carts. (Actually, acceleration due to gravity in freefall seems curiously slightly ''slower'' than ramp acceleration.) Ramp acceleration, while it logically should be partially z-directional, is only recorded as x- or y-directional, and there is no translation of z-directional velocity upon landing. Landing carts zero out their vertical velocity upon landing, even when landing on ramps, although carts that had horizontal momentum while falling preserve it.

This means a cart falling (from a hatch, thus with no horizontal speed) onto a track ramp is accelerated as if starting from the middle of the ramp - i.e. to the same speed, no matter how many Z-levels it was dropped, vertical velocity is negated. {{cite forum|144328/5701211}}

Carts falling onto a floor can, however, cause damage to creatures ''one tile below the floor''. This can be used in an [[exploit]] called a "thumper", where carts are caused to repeatedly fall on a floor above an entrance to the fort, inflicting significant damage (as though it were a collision) on those below the cart.

=== Cart Jumps ===
Carts that cross off of "up" ramps relative to their current direction of travel, which do not have a ceiling above them, are traveling above derail speed, and do not have valid ramp track before them can translate a portion of their horizontal velocity into vertical velocity, causing a cart to be projected into the air until vertical velocity is negated and overcome by the gravitational acceleration. Because downwards acceleration is applied per-tick, this creates a reasonable facsimile of the parabolic motion of an actual object rolled up a ramp and launched with significant speed.

{{diagram|spaces=yes|\
z0 z0 hiding ramps z+1 A z+1 B (hidden ramp)
▒▒▒▒▒▒▒▒▒▒▒▒ ▒▒▒▒▒▒▒▒▒▒▒▒ ▒▒▒▒▒▒▒▒▒▒▒▒ ▒▒▒▒▒▒▒▒▒▒▒▒
═▲▲▲▲▲══▲▒▲═ ═╚╚╚╚╚═══▒══ ▼▼▼▼▼ ▼═▼ ▼▼▼▼▼ ▼╚▼
▒ : Wall
═ : track
▲ : Ramp
}}
In this diagram, if there is no ceiling above it, the track in z+1 A will launch its carts airborne when they travel across the ramp. z+1 B (with a ramp on the tile on the hill) will not launch the cart. The cart would also not be launched with ''any'' valid ramp, even if it does not travel in an appropriate direction, such as North/South (which the cart will ignore, as it is not a curve, anyway, although it may produce acceleration that may cause diagonal movement.)

Carts that are traveling at derail velocity will also start "jumping" from the track if it hits an un-tracked tile, flying over and ignoring any tracks until it is ready to land. Carts that land upon tracked tiles re-rail themselves, and clever designers use this feature to jump over curved track sections in one direction or another. (Retracting bridges over untracked tiles can cause jumps or not cause jumps depending upon the status of the bridge.) Minecart speed must be carefully regulated to ensure reliability of jump length.

Hitting untracked tiles at around 70k velocity creates a vertical component to acceleration that allows for jumps of around 6 (horizontal) tiles that do not actually leave the z-level the cart is on, but which do apply z-direction velocity on the cart, as per falling.

Carts that approach a downward slope at a high enough velocity will also make a jump, (or rather, ignore the ramp and fly forwards) but will not do so if the [[#Checkpoint Effect|Checkpoint Effect]] is exploited through an impulse ramp before the actual downhill as the impulse ramp "tricks" the cart into thinking it has already started going downhill. The cart will also not fly off the ramp if there is a wall and ceiling preventing any motion but going down the ramp.

=== Skipping ===
If a minecart is moving fast enough, it can skip over [[water]] or [[magma]], making splashes of [[mist]] (or [[magma mist]]) as it attempts to move on them horizontally. This horizontal movement is independent of the minecart and its content's [[weight]].

Skipping causes significant friction on the cart, and even a cart going at max speed from ramps can only make about 50 tiles without requiring re-acceleration. (Carts that decelerate enough that they do not trigger the skipping effect will, of course, sink.)

=== Corner Ramp Derail ===

Corners on upward ramps can cause diagonal movement, forcing a derail even if the cart has a wall next to it, which will force a stop when it touches a wall that forces dwarves to manually reset the cart.

This is caused by the fact that a cart, after turning the bend in the track halfway through the length of the tile, will still "accelerate down", which is now perpendicular to the movement of the cart, causing acceleration to occur in two directions. (Down corner ramps do not have this problem, as when they pass the halfway point, all perpendicular motion is added to forward motion, and after that curve, all downward acceleration is in the forward direction.)

There are two fixes to this problem. One is to simply not put corners on up ramps. The other is to "cancel" the lateral speed after a cart has passed the ramp, either by sending the cart through another corner or by putting a high-friction track stop on the exit tile. In the latter case, the cart will lose 10000 speed in the desired direction, but the same speed loss will apply to the undesired lateral speed, nullifying it.

=== Checkpoint Effect ===
The checkpoint effect, [http://www.bay12forums.com/smf/index.php?topic=144328.0 explained in depth by Larix], is an odd and highly exploitable feature of ramps where minecarts "teleport" through the next tile of track, ignoring nearly all minecart physics (except that they stop at all walls or other obstacles and only respect curves with no backing wall and invalid ramps if they are below derail speed) and passing through that tile in just a single tick, and into the next tile at the halfway point.

This effect occurs when a cart leaves a downward ramp for any other direction of tile. (This includes ramps which accelerate in different directions, even a ramp which goes from accelerating East to accelerating North due to a bend in a chain of standard down ramps in a curve.) This allows, for example, two valid straight ramps directly next to one another with a cart dropped onto one or the other with no momentum to have the cart pick up acceleration going "down" the ramp as normal, but then flying up through the "up" ramp it travels into with no loss of momentum, as though it had come from an impulse ramp. If the two ramps had at least one space of distance between them, and then a cart were dropped in, the cart would instead "rock" back and forth between the two ramps.

This seems to be because ramps have a slightly longer length than regular tiles - 144,000, rather than 100,000 distance. When this "snaps back" after a ramp, it seems to project the cart suddenly further along the track, making it jump a tile ahead even when otherwise moving at relatively low speeds.

This [[bug]] is the cause of a ''wide array'' of unexpected behavior among people who do not take this bug into account. It causes derailments or failure to climb up seemingly valid impulse elevators. In general, it makes a system that behaves extremely counter-intuitively, and operates ''any time a cart encounters a valid ramp''. At the same time, when its effect is accounted for, it is highly exploitable: It causes "perpetual motion devices" using no power when two opposing ramps are placed next to one another, since the "uphill" effect of the opposing ramp is ignored, preventing deceleration.

Another useful thing to note about this exploit is that carts traveling at no less than 72,000 or so speed (enough to travel half a ramp tile in a single tick) can travel through every tile in just one tick at no change in velocity as long as the tiles alternate between impulse ramp or actual down ramp and any other tile type. The cart checkpoints through the non-down-ramp tiles, and can pass through the (impulse) down ramp tiles in a single tick, before they can actually start gaining momentum.

{{diagram|spaces=yes|\
▒▒▒▒▒▒▒▒▒▒ ▒▒▒▒▒▒▒▒▒▒
═▲═▲═▲═▲═▲═ ═╚═╚═╚═╚═╚═
▒ : Wall
═ : Normal track
▲/╚ : N/E Track/Ramp
}}

If the cart enters from the West at less than 72,000 speed, some of those ramps will cause Eastward acceleration.

This means that an impulse ramp not contiguous to other impulse ramps has a top speed of around 75k:

{{diagram|spaces=yes|\
▒▒▒▒▒ ▒▒▒▒▒
▒╔═╗▒ ▒╔═╗▒
▒╚▲╝▒ ▒╚╗╝▒
▒▒▒▒▒ ▒▒▒▒▒
}}
This setup makes a cart that travels clockwise at a speed that fluctuates around 75k velocity. If the cart has more than 72k velocity, it fails to accelerate in the ramp, as it leaves the ramp in a single turn due to checkpointing to the halfway point. After that, the curves sap 1k velocity, and every tick saps 10 velocity.

Two contiguous impulse ramps with a same-facing "downwards slope", however, do not suffer the checkpoint effect in the second tile, giving functionally triple the space to accelerate. This means it will add velocity (at the standard rate of 4.9k per tick) up to a maximum speed of 216k.
{{diagram|spaces=yes|\
▒▒▒▒▒▒ ▒▒▒▒▒▒
▒╔══╗▒ ▒╔══╗▒
▒╚▲▲╝▒ ▒╚╗╗╝▒
▒▒▒▒▒▒ ▒▒▒▒▒▒
}}
This example results in a cart moving three times as fast as the previous cart.

Three successive ramps results in the highest attainable speeds.

In practical terms, this means that only consecutive ramps should be used for high acceleration, but singleton ramps can be used to have speeds that are somewhat regulated.

=== Stacking ===
If a minecart lands on top of another minecart, they may form a stack, with the upper cart on the z-level above the lower. Subsequent carts do not form a stack, but rather quantum stockpile in the same space. This behaviour is useful for [[megaprojects]] and [[trap design]] with minecarts as the weaponry. Moderation should still be exercised: carts take longer to fall into a "stacking" tile already occupied by other carts and will spend that time "hanging" in the air above the stack. This can lead to following carts striking them, which can cause all kinds of malfunctions. The extra time is two game steps for every cart already in the stack, which doesn't hurt stacks of ten carts very much but makes stacks of 100+ rather impractical.

These minecarts on the upper level generally need to be struck with another minecart to move out, or have their support removed. The latter option is safest done by shooting it away with another minecart, manual removal of a stack-supporting cart typically causes the next cart from the stack to [[fun|fall on top]] of the hauler.

=== Perfectly Elastic Collisions ===
Minecart collisions are perfectly elastic, meaning that not only do minecarts not take damage, but that two carts that are rolling which have frontal collisions of near-similar speed, and where one cart is no more than twice the mass of the other cart, will result in a billiard-ball-like effect of the lighter cart bouncing off the heavier cart with a proportional speed increase dependent upon the relative momentum behind the heavier cart.

Using this trick with carts already at the 270,000 maximum speed from ramps can result in "supersonic" carts traveling at speeds in the millions (travelling a dozen tiles per tick), but where they are suddenly subject to 10,000 units of "terminal velocity" friction per tick. [http://www.bay12forums.com/smf/index.php?topic=137557.0 Thread with SCIENCE here].

While hypothetically capable of launching a minecart into orbit when used in conjunction with a ramp, no cargo can be contained in the launched cart, as the collisions will force ejections of the cargo. Your "unwilling volunteer" [[goblin]] space pioneers will simply become paste underneath the wheels of an extreme high-speed cart.

== Non-standard uses ==
Minecarts include some interesting characteristics that have motivated uses beyond hauling. They can be useful for creating fully-automated [[exploit|quantum stockpiles]] and [[garbage disposal]]s. Storing perishable goods (meat, meals, etc.) inside a minecart appears to guard against rot and vermin.
Minecarts can be [[Trap_design#Minecarts|used as weapons]], or as (hopefully non-fatal) triggers to restart stalled [[healthcare]]. They can also be used to time/control game events, either using a basic [[repeater]] or much more advanced [[minecart logic]].
Minecarts trigger [[pressure plate]]s, which means a trap can be designed to trigger when a thief attempts to steal a minecart.
A pressure plate can be used as automatic and more precise custom "launch when full enough" system - as long as weight of your minecarts stays the same. You cannot build a hatch or roller on the same tile, so launch by bumping with another cart. {{cite forum|15096/4580050}}
Dwarves riding minecarts can attack enemies within reach (which goes back to dev log). This applies to shooting, and they actually can hit targets while riding by.{{cite forum|109460/5266119}} Whether a minecart protects the rider and how it interacts with dodging is not known yet. Minecart riders can also [[Swimming#Minecart_training|train swimming]] and [[Megaprojects#Surveillance_Track|detect ambushers]].

== Adventure mode ==
In addition to being used for hauling, minecarts can also be ridden in [[adventure mode]]. (Adapted from forum thread {{cite forum|122903/4258212}})

# If the minecart is in your inventory, drop it. If it is already on the ground, proceed to step 2.
# Press {{k|u}} when you are 1 tile away from the minecart (or standing on the same tile as the minecart).
# You will be presented with the following options:
[[File:minecart adventure mode menu.png|left]]
{{clear}}
* If you {{DFtext|Push}} the minecart, it will move a few tiles in the direction you chose. Physics comes into play here, so it will gain/lose speed depending on the usual factors.
* If you {{DFtext|Ride}} the minecart, you will hop into the minecart, even if you were a tile away, and it will move in the chosen direction with you in it. It will gain/lose speed depending on the usual factors. Whilst the minecart is in motion, you should press {{k|.}} to skip your turn; if you attempt to move whilst the minecart is still in motion, the laws of physics come into play, and you will take [[wound|damage]]. Alternatively, you can push the minecart whilst it's still in motion (although it's unclear how one can bend [[physics]] so as to push a moving minecart whilst inside the minecart). If you push it in the same direction you are already travelling in, you will greatly increase the minecart's velocity. You can also push it in different directions, and this will cause it to gradually change direction-the amount of pushes this requires depends on the minecart's velocity. Once the minecart has stopped moving, you may move out of it safely, or you may want to give it another push. Note that if you push a minecart right after having ridden it (still on the same tile as the minecart), it will act as though you chose to ''ride'' it.

If you want to test this out without creating an adventurer, the [[object testing arena]] allows you to spawn minecarts ({{k|k}}-{{k|c}}-{{k|n}})

== Forging and Melting ==
* Metal minecarts cost '''two''' [[metal]] bars to forge, or '''six''' [[adamantine]] wafers.
* When a non-adamantine metal minecart is melted down, it will return '''1.8''' metal bars, for an '''efficiency of 90%'''.
* When an adamantine minecart is melted down, it will produce '''1.8''' wafers, for an '''efficiency of 30%'''.

== See also ==
* [http://www.bay12forums.com/smf/index.php?topic=109460.0 The "How Does Minecart" Thread] by '''Girlinhat''' et al.
* [http://www.bay12forums.com/smf/index.php?topic=112831.0 SCIENCE: Quantifying minecart physics] by '''Snaake''' et al.
* [http://www.bay12forums.com/smf/index.php?topic=129676.0 How to build a Multi-cart Ore to Magma Minecart Project without needing power] by '''WanderingKid'''.
* [http://www.bay12forums.com/smf/index.php?topic=144328.0 My very own Minecart Education Thread. Ten Lessons, now complete.] by '''Larix'''.

== Bugs ==
*A dwarf will drop her [[child|baby]], if she has one, when boarding a minecart set to be ridden.
*Dwarves have no concept of traffic safety and will walk into busy minecart lines to retrieve objects, often with deadly consequences. This is especially problematic in [[Swimming#Minecart_training|clever applications]] depending on dwarves riding the carts very frequently, because they have a bad habit of dumping their worn clothes on the tracks after a minecart ride. Adding an automatically-operated [[hatch cover]] at the end of such a ride can help prevent [[unfortunate accident]]s.
*Dwarves cannot guide a minecart through an unlocked door unless another dwarf opens the door.{{bug|6056}}
*It is possible for a creature and minecart moving towards each other to pass without collision if they exchange tiles in the same tick.
*After a minecart ride, a dwarf will sometimes haul the minecart to a storage stockpile, leaving another dwarf to haul the vehicle back to the route.
*Minecarts falling onto a floor injure creatures in the tile below the floor.{{bug|6068}}
*A minecart's initial velocity is not affected by weight, when pushed or launched from rollers.{{bug|6296}}
*Removing a stop that has a vehicle waiting on it may cause the game to crash.{{bug|5980}}

{{Category|Fortress mode}}
{{Category|Interface}}

[[ru:Minecart]]

Minecart

2015-07-04T23:32:03Z

NW Kohaku: /* Troubleshooting */ Set dir/connect track description expansion

{{Quality|Masterwork|08:15, 19 May 2015 (UTC)}}
{{av}}
A '''minecart''' is a [[tool]] intended for [[hauling]], introduced in version 0.34.08. It can be made of [[wood]] at a [[carpenter's workshop]] or [[metal]] at a [[metalsmith's forge]] (using the [[Metal crafter|metalcrafting]] labor.) Minecarts store up to five times as many items as [[wheelbarrow]]s and are quite a bit faster than dwarves hauling objects by hand, but have the disadvantages of requiring a dedicated track network, a complex route planning phase, and the possibility of dwarves [[Fun|blundering into the path of carts filled with lead ore]]. Tracks may be carved into stone, or [[Construction|constructed]]; the latter allows above-ground routes, but these are more difficult to set up due to their additional [[building material|material requirements]].

Just like wheelbarrows, minecarts are considered [[item]]s and are stored in a [[furniture]] [[stockpile]]. Despite their five-times-greater capacity, they are only 33% larger than wheelbarrows and are identical in base [[item value|value]] when made from the same [[material]] (the value may differ due to the [[item quality]]). [[thief|Thieves]] or even mischievous animals can steal minecarts, even when they are moving on a track{{cite forum|109460/3289070}}. However, minecarts moving fast enough or being ridden cannot be stolen.

Although most of the utility of minecarts is in [[fortress mode]], an [[adventure mode|adventurer]] can also ride in a minecart. Adventurers can also pick up and relocate minecarts.

The invention of minecarts revolutionized the [[minecart logic|Science of Dwarfputing]] by enabling smaller, faster logic systems to be built.

== Basic Minecart Usage ==
Minecarts can be used to swiftly transport dwarves, [[flow|fluids]], and/or large amounts of items, but before you have a functional minecart there are several preconditions that need to be met. First of all you need an actual minecart, constructed either in a [[carpenter's workshop]] or [[metalsmith's forge]]. For the minecart to be able to move you also need to carve (with {{k|d}} {{k|T}}) or construct (with {{k|b}} {{k|C}} {{k|T}}) a track, which could be as simple as a straight line. Finally you need to construct stops on your track (with {{k|b}} {{k|C}} {{k|S}}) where the minecart will start and stop.

After you have created the stops and assigned a cart to the track, you must create logic routes connecting several stops and designate starting conditions for each stop. This is done with the {{k|h}}auling key. The most basic conditions are how the cart's movement is initiated and in which direction the cart should start moving. Carts can be either be Pushed (a dwarf stands at a stop and gives the cart a single push) or Guided (a dwarf continually pushes the cart forward, guiding it along the track). The [[hauling]] [[labor]] required for pushing and guiding carts is called "Push/Haul Vehicles" and is turned on by default.

To control which items to transport you can add conditions specifying: (1) which kind of items to be loaded, and unloaded, (2) stockpile links to define which stockpile(s) the items should be un/loaded to and from.

===Capacity and weights ===
Minecarts have five times the [[Weight|capacity]] of [[wheelbarrow]]s.

'''Examples of the capacity of one cart'''
{| class="wikitable"
|-
! Item
! Amount
|-
| [[stone]]
| 5
|-
| [[wood|log]]
| 10
|-
| [[block]]/[[bar]]
| 83
|-
| [[Kitchen|prepared meals]]
| 500
|-
| [[Trap_component#Spiked_ball|spiked balls]]
| 500
|-
| [[Weapon#Native_weapons|mace]]
| 625
|-
| [[Weapon#Native_weapons|spears]]
| 1250
|-
| [[cloth]]
| 2500
|}

The weight of the loaded minecart does not affect the initial velocity received from pushing or launching from a roller. However, the load of a minecart ''does'' affect whether a [[pressure plate]] triggers or not, based on the pressure plate's setting.

'''Weights of different carts'''

{| class="wikitable"
|-
! Type of cart
! Empty cart
! Fully loaded (items)
|-
| oaken minecart
| 28Γ
| 378Γ (10 oak logs)
|-
| platinum minecart
| 856Γ
| 10482Γ (83 gold bars)
|}

The weight of a minecart is one twenty-fifth (1/25) the [[density]] of its material in Urists. Because pressure plates can be set to trigger at intervals of 50 Urists, minecarts with weights just under a multiple of 50 are ideal for switching based on whether they're full or empty. The best minecart materials for full/empty switching are as follows:

{| class="wikitable sortable"
|-
! Material !! Minecart weight !! Content weight required to trigger !! Banana roasts required to trigger (for scale)
|-
| [[Bismuth]] (moods only) || 391 || 9 || 15
|-
| [[Brass]] || 342 || 8 || 14
|-
| [[Electrum]] || 596 || 4 || 7
|-
| [[Fine pewter]] || 291 || 9 || 15
|-
| [[Glumprong]] || 48 || 2 || 4
|-
| [[Lay pewter]] || 291 || 9 || 15
|-
| [[Nickel silver]] || 346 || 4 || 7
|-
| [[Tin]] || 291 || 9 || 15
|-
| [[Trifle pewter]] || 291 || 9 || 15
|}

=== Creating tracks ===
Minecart tracks are made up of contiguous track, tracked ramp, or bridge tiles. Track tiles and tracked ramp tiles have a direction or series of directions associated with them. These directions dictate which directions a minecart on a given tile may move from that tile. For example, a Track NE (northeast) tile allows a minecart on it to move either north or east from its present position. Therefore, if you want your minecart to move east along a straight piece of track, then return west using that same track, you would need to use EW tracks so that the cart could travel east initially, then return west over the same track. Excluding designs in which the cart will "jump" tracks via a drop or other ramp, tracks must be valid end to end to work for most looped or straight-track applications. A single east only track tile in your line of east-west tracks will cause any route using the track to fail the moment it tries to go the wrong way over that tile. Minecart tracks can be built in two ways: Engraved/carved or constructed. A given minecart track need not use engraved or constructed elements exclusively, as the two methods can be used interchangeably depending on the needs of a given section of track. The way the tracks are built is slightly different between the two, as explained below.

====Simple tracks====

'''Carved'''

A single-tile wide strip of natural stone can be designated to be [[Engraver|carved]] (with {{K|d}} {{k|T}}), which will create a straight two-way track. The creation of corners, crossings, and T-junctions is as simple as designating another strip of track that overlaps an existent or newly designated track. Engraved tracks are removed by [[smoothing]] the rock they're on, which results in a smooth floor (that can be re-engraved if necessary), or by building a [[floor]] on top and subsequently removing it. Dwarves can carve corner tracks in one pass by designating the track carving twice and canceling unwanted carvings (with {{K|d}} {{K|x}}). Tracks can be engraved in any natural floor tile, rough, smooth and even over engravings, providing an easy method to remove low-quality or undesired floor engravings. Once a track has been engraved, it's important to check the track directions for each tile in the route carefully to make sure no mistakes were made by yourself or the game's track engraving logic.

'''Constructed'''

Tracks can also be built as regular [[construction]]s (through {{K|b}} {{K|C}} {{K|T}}). This method is resource-expensive, since each track tile requires one stone, [[bar]], or [[block]] for construction, and time-consuming, since you can't designate strips longer than 10 tiles at a time. Corners, crossings, T-junctions, and ramps also have to be designated individually. However, it is usually the only way to build tracks above ground or on soil (barring the [[Obsidian farming|creation of obsidian]]). Constructed tracks are designated for removal like any regular construction; be aware that removing track ramps built on top of natural ones will also remove the original ramp, leaving a flat floor.

====Ramps====

'''Carved'''

The carving of natural ramps is a little more confusing: to carve a two-way track on a ramp (natural only, does not work on constructed ramps), you must designate the track '''starting on the ramp and one square beyond''' in the direction you want the track to go. For the side of the ramp square you want to head upward, there '''must''' be either a natural or constructed wall in the square next to it, otherwise the game assumes you are trying to carve it on the same level -- this can result in the track being carved underneath a door or other object. If you have accidentally done this, you can correct it by smoothing the ramp and constructing a single square of wall next to it, then re-carving the ramp correctly. (However, the wall must stay there permanently; removing it will disconnect the track.)

'''Constructed'''

When constructing track ramps, the stated direction should be the same as the connected tracks. For example, a track going up from West to East would require, starting from the West, a Track (EW), a Track/Ramp (EW) and a Wall behind the ramp, underneath the section of track above it. Incorrectly placed ramps result in minecarts ignoring the ramp and crashing into the supporting wall. They will not, however, display as unusable as when the supporting wall is missing.

'''Examples of ramps'''

A simple ramp would look like this:
{{diagram|spaces=yes|\
z +0 z +1
░░░░ ░░░░
═▲o ░▼═
░░░░ ░░░░
o : wall
}}

Carving track corners into ramps is rather unintuitive and complicated. Since engraving tracks always requires two tiles to connect in a straight line as input, you have to give two separate designations for a single job: a track bit from the ramp tile to the "below" direction and another one to the wall of the "upward" direction. If you wanted to change direction on a ramp from east to north:
{{diagram|spaces=yes|\
z +0 z +1
░░░░░ ░░░░░
░░░░░ ══╗░░
=▲░░ ░░▼░░
░░░░░ ░░░░░
}}
you would need to connect the ramp on z +0 both to the west and to the north by issuing two "carve track" commands, one selecting the ramp and the track tile to the west, and another connecting the ramp tile with the wall to the north. An engraver would then carve a NW track corner into the ramp, allowing carts to pass the corner correctly both going up and down. Such track corners are perfectly serviceable for guided carts, but moving down a route of several of them by pushed or ridden cart is problematic - ramps on corners behave very counter-intuitively, resulting in loss of speed when going down and diagonal movement when going up.

Moving to and from ramps (or between ramps "pointing" in different directions0 causes some non-trivial adjustments to speed and even moving along the tiles at a fixed speed ''unrelated to the entry/exit velocity values'', because transitions to/from ramps are processed differently and are not to be "skipped". This affects compact track/ramp combinations (such as e.g. a simple 2x2 ramp spiral) most, and combined with bouncing often makes them work not in the way one could expect. {{cite forum|144328/5705102}}

{{anchor|Tracks}}

=== Hauling route ===
A hauling route is a list of directions describing how and under what conditions a minecart will move. The proper setting up of routes is essential for a working rail system. Routes, stops, departure conditions and stockpile links are managed from the {{k|h}}auling menu.

==== Route ====
A route defines the path a minecart will take along a track, as well as under what conditions it will move or stop moving. A route is made up of stops. Stops are precisely what they sound like, a position on the track at which you want a minecart to stop. A minecart track might use as little as a single stop for a looped track, which will serve as both a starting and stopping point for the cart, or it could contain many stops, perhaps to load supplies or wait for a bridge to be manually lowered, before reaching its destination or returning to its starting point. It is important to note that you only need to place stops on a route where you actually want the cart to stop and wait for some action to occur. They are not needed to help navigate the cart along the track beyond telling it where on the track to stop.

New routes are created with the {{k|h}}auling key. Existing ones can be removed (without confirmation) with the {{k|x}} key, and also {{k|n}}icknamed. Before operating, the route must have a {{k|v}}ehicle assigned to it (this can be done with either the route or a stop selected). Assigning a full minecart to a route may result in a slow hauling job if the contents are heavy.

==== Stops ====
Stops are the individual waypoints that make up a hauling route. A given stop consists of the location of a tile, as well as conditions describing when, where, and how a cart should be moved after being stopped at that tile. Stops can be created from within the {{k|h}}auling menu, by placing the cursor over a tile and hitting {{k|s}} while highlighting the route (or a stop within) you've already designated. A minecart will begin its route at the first stop created, and continue through each subsequent stop, being guided, pushed, or ridden from each stop to the next depending on the conditions specified. In many basic minecart applications, the cart will end up at the same stop it began at, though this is not always the case. It is important to note that hauling stop order is enforced, even if there is no track. A dwarf will drag the cart overland back to a skipped stop in the route's list if your tracks bypass it somehow.

Once a stop has been placed, it is given a default set of conditions under which to move the minecart if it is stopped there. Each new stop gets the same default conditions regardless of the track it is placed upon (e.g. guide the cart to the north). For this reason new stops might get marked by yellow exclamation marks ({{DFtext|!|#ff0}}) due to invalid directions. One important thing to note is that as you place additional stops, the display will show paths between the stops you have defined. However, this is '''not''' necessarily the actual route the minecart will take once the route is in operation. For example, if a route were defined with two stops at opposite ends of a track with many twists and turns, a line will be drawn directly between those stops to show the order in which they will be visited. These route lines may crisscross all over the tracks, but so long as the track is valid end to end, the cart will follow the track from one stop to the next, even across twists, turns, and z-level changes. Stops, which are the steps that make up a route, should not be confused with Track Stops, described below.

===== Stockpile links =====
By placing the cursor on top of a stockpile and using {{k|s}}, you can create stockpile links while defining a hauling stop. Links can also be redefined by selecting them, placing the cursor over a different stockpile, and pressing {{k|p}}. The cart will then be filled by items present in its various linked stockpiles in preference to other items. Note that bins should be used with caution in stockpiles that are linked to minecarts. Bins cause problems when used with the "Desired Items" list in a stop's conditions. For example, if a minecart is set to accept only granite blocks, and to depart north when it is 100% full of granite blocks, it will not depart if any of those granite blocks are in bins, even if bins are also included in the desired items list. Two solutions to this problem exist as of v0.40.24. First, bins can be disallowed in stockpiles that are linked to stops. Alternatively, bins '''can''' be used in conjunction with minecarts provided that the minecart's departure conditions use only "any items" instead of "desired items." This option can be toggled in the advanced conditions menu for a stop, accessible via the {{key|C|}} key. The cart's contents can still be controlled by specifying what items are allowed in the linked stockpile.

===== Departure condition =====
Departure conditions involve setting conditions in which the minecart will leave on the route. Each condition includes:
# A departure mode (Guide, Ride or Push).
# An initial departure direction (NSEW). Note that this defines the initial direction of movement only. Even if a track includes many turns, as long as the initial movement direction is valid the cart will follow the minecart track thereafter.
# A timer, before which the departure condition cannot be met.
# Conditions on the amount of items in the cart.
Departure conditions are created with the {{k|n}} key. A new departure condition will read: "guide north immediately when empty of desired items". This condition can be changed between basic presets with {{k|c}}. "Advanced" mode ({{k|C}}) allows for more precise control over departure conditions: fine tuning the percentage from 0 to 100 in 25% steps ({{k|f}} and {{k|F}}), switching it being either the maximum or the minimum amount of items for the condition to be met ({{k|m}}), and whether the cart accepts all or only a specific set of items ({{k|l}}). Common to both screens are the departure mode ({{k|p}}, Push, Ride or Guide), {{k|d}}irection, and timer ({{k|t}} and {{k|T}}) options.

To have a cart only carry a specific set of items, the stop can be set to only carry "desired" items, opening the selection screen with the {{k|Enter}} key while having said stop condition selected, and toggling as desired, or it can simply be linked to a stockpile and set to depart once it is full of items from its linked stockpiles, regardless of type.

=== Track Stops ===
A Track Stop, not to be confused with a route stop, is an optional, single-tile construction which serves two purposes. First, it can be used to cancel a cart's momentum in order to slow or stop it as it passes over the Track Stop. This might be necessary if a cart were pushed down a series of ramps to its destination. Second, a Track Stop can cause a cart to automatically dump its contents as it passes over the Track Stop. Track Stops are constructed via {{k|b}} {{k|C}} {{k|S}}, and must be constructed atop an existing piece of track. If a Track Stop has been set to automatically dump a cart's contents, the cart will dump its contents in the direction indicated when it passes over the Track Stop. Depending on the friction settings chosen for the Track Stop, the cart might then stop after dumping, or it might continue on its route to another destination.

Track Stops are not mandatory; in fact, their main use is in automated rail systems. However, even in basic rail systems it can be useful to set a Track Stop to dump items: this saves time that dwarves would otherwise spend in removing items from the cart, time that is better spent driving the cart back to where it's needed. Dumping will occur even with a guided cart. '''Take care not to set Track Stops at a loading site to dump their contents''', or dwarves will never be able to fill the cart. It will dump any contents the moment they are loaded.

Counter-intuitive to their construction method, Track Stops are considered [[building]]s and must be removed by {{k|q}} {{k|x}}.
* See [[#More_on_Track_stop |More on Track Stops]]

=== Step-by-step tutorial ===

Let's construct a simple minecart route. This route will move stone blocks from an input stockpile to an output stockpile. We'll begin by creating the stockpiles:

[[File:minecart-example-1.png|Stockpiles designated.]]

The input stockpile is on the left; the output stockpile is on the right. We'll be moving blocks from left to right. Disable bins in both stockpiles, and set the input stockpile to accept only from links. Then make the stockpile take from the mason's workshop where the blocks are being produced.

Next, carve the track:

[[File:minecart-example-2.png|Track carving designation.]]

Note that the ends of the designation are uniquely shaped; this is automatic, and not anything you need to control. Now, wait for your engravers to come along and carve the track into the stone. (Your haulers will probably also fill up the input stockpile while you wait.)

In addition, while we're waiting for that to happen, we'll build an iron minecart in the forge.

[[File:minecart-example-3.png|Track carved.]]

When the track has been carved, it will look like the above (the track will be solid instead of flashing). Now, order a track stop to be constructed next to the output stockpile:

{|
| [[File:minecart-example-4.png|Track stop designation.]]
| [[File:minecart-example-5.png|Select dumping direction.]]
|}

You must press {{k|d}} three times to select the dumping direction ''before'' placing the track stop. We want our blocks to be dumped into the output stockpile east of the track stop. Then wait for a mechanic to come along and build the track stop.

[[File:minecart-example-6.png|Track stop constructed.]]

Now we'll define the actual ''route''. This is done in the {{k|h}}auling menu. Press {{k|r}} to begin defining a route. Next, move the cursor to the input end of the track, and then press {{k|s}} to define the first stop:

{|
| [[File:minecart-example-7.png|Stop 1 designation.]]
| [[File:minecart-example-8.png|Route definition, in progress.]]
|}

Move the cursor again, to the output end of the track, and press {{k|s}} again to define the second stop:

{|
| [[File:minecart-example-9.png|Stop 2 designation.]]
| [[File:minecart-example-10.png|Route definition, two stops.]]
|-
|
| [[File:minecart-example-11.png|Stops are not defined yet.]]
|}

There are several user interface features to note at this point. The stops have been positioned, but they haven't been ''defined'' yet, so there is a warning {{DFtext|!|#ff0}} symbol by each of them. In the lower right corner, we see what the {{DFtext|!|#ff0}} means. Also, note that the second stop is labeled in white, while the other two lines are grey. The white text is a selection indicator, and can be moved up and down by pressing {{k|+}}/{{k|-}}.

Next we need to define what our stops do. We want the minecart to be filled with blocks at the first stop, then travel to the second stop where it will dump its cargo, and then return. Press {{k|-}} to move the selection up to stop 1, and {{k|Enter}} to open it up. By default, the stop has three conditions:

[[File:minecart-example-12.png|Default stop definition.]]

We don't want any of these, so press {{k|x}} three times to delete them. This leaves us with a blank stop. Now we can add the conditions we actually want. Press {{k|n}} to begin adding the first condition, then {{k|d}} twice to change the direction from north to east. Then press {{k|c}} to change the condition from empty to full. This will instruct the minecart to be guided east when full of desired items.

To set the desired items, we create a stockpile link. Press {{k|s}}, then move the cursor to the input stockpile, then press {{k|p}} to select that stockpile. Now press {{k|Enter}}; this opens up a selection screen that resembles the stockpile customization screen. Move down to Blocks, {{k|e}}nable them, then (if you wish) restrict it to stone blocks.

When you've done all that, stop 1 should look like this:

[[File:minecart-example-13.png|Stop 1, defined.]]

Stop 2 is much simpler. All we need to do is have the minecart return to the input stop. So, make a condition and change the direction:

[[File:minecart-example-14.png|Stop 2, defined.]]

Finally, we just have to assign our minecart. Go back to the route definition screen, and press {{k|v}}. Select the minecart, and press {{k|Enter}}.

Now we've got everything set up:

[[File:minecart-example-15.png|Route, fully defined.]]

The V is red because the minecart hasn't been moved onto the track yet. Some dwarf will have to haul it from the forge to the first stop, by hand; this will take a while, especially if the forge is far away.

Once the minecart is in place, dwarves should fill it with blocks from the input stockpile, which will in turn be filled with blocks from the workshop where your mason has been toiling dutifully. When the minecart is full, the blocks will be dumped into the 1x1 stockpile on the right. Automatic quantum dumping!

=== Troubleshooting ===

Because of the complexity of the system, all but the most careful and experienced minecart users will encounter issues. Most route issues can be diagnosed and fixed from the {{k|h}}auling menu.

'''Symptom:''' {{DFtext|! Set dir/connect track|6:1}} message appears to the right of one or more stops

'''Possible Causes:'''
* In basic terms, the game checks if there is a valid path for a cart along the rails to reach the next stop in the route, and whether a dwarf ''guiding'' a cart would be able to find a path to the destination without carrying the cart. This warning pops up if the cart can't find a valid path based upon guided carts.
** If your cart path relies upon advanced tricks like deliberate falling into pits or ignoring floor types, even a path designed entirely as you intended will still trigger the yellow warning. (But double-check to make sure it's fine...)
* The departure direction of the stop might be invalid. Edit the stop using {{k|Enter}} and press{{k|d}} until it is pointing in a valid direction.
* The track stop might not be built on top of a track. The track stop must be deconstructed to remedy this issue.
* Your track might not be built correctly. Make sure all connected tracks between destinations are not one-way tracks.
** This can be especially confusing with ramps. To carve a two-way track on a (natural) ramp, you must designate the ramp and one square beyond in the direction you want the track to go.
** Ramps '''must''' have a solid block on the side opposite to the track, or they will neither work nor be marked as "unusable". The solid block can be natural or constructed.
* The desired/kept items might not be configured correctly.

'''Symptom:''' The status '''0% V''' always appears to the right of one stop.

'''Possible Causes:'''
* The stop may not be set to take from a stockpile. Edit the Stop using {{k|Enter}} and make sure you see a message like "Take from Stockpile #1".
* The take conditions must correspond with the contents of the stockpile.
* The track stop may be set to dump. A track stop set to dump cannot be filled. You must either set the stop to a time-based departure or deconstruct the track stop and rebuild it without dumping. (Alternatively, with [[DFHack]] you can modify "Dump on arrival" to "No" using the {{key|q}} menu without rebuilding the stop.)
* Make sure the minecart itself has not been designated to be dumped (such as when using mass-dump).

'''Symptom:''' Dwarves fill the minecart properly, but will not move it thereafter.

'''Possible Causes:'''
* The minecart may contain items which are not included in its current stop's desired items. Check inside the minecart using the {{key|k}} and {{key|z}} keys and ensure that all items in the cart are desired items.
* The minecart may contain desired items in bins. Minecarts seem to have problems realizing that they are in fact full of desired items if some of those items are in bins, even if bins are also among the desired items for that stop. '''This cannot be solved by adding the appropriate bins to the stop's desired items.''' Either disallow bins in stockpiles you intend to load minecarts from, or set the departure conditions to rely only on percentage of total load rather than percentage of desired items using the advanced conditions menu ({{key|C}} key).

'''Symptom:''' Dwarves repeatedly attempt to load the minecart, but no items are ever loaded into it.

'''Possible Causes:'''
* This can be caused by using a Track Stop with autodumping enabled at a loading site. Every time a dwarf places an item into a cart resting on such a track stop, the item will be immediately dumped, causing unlimited, useless cart loading jobs. Autodumping Track Stops should never be used at a loading site.

'''Symptom:''' A dwarf picks up the minecart and carries it to its destination.
* See [[#Quirks|Quirks]]

=== Danger ===
Minecarts are not without <strike>danger</strike> [[fun]]. Although designating a track automatically sets the [[traffic]] designation to low, dwarves ''may'' still walk on them, and [[creature]]s ignore traffic designations altogether. If an unlucky dwarf or creature fails to [[dodger|dodge]] a minecart, they can be injured. Most of this danger can be avoided by setting the minecart {{k|h}}auling commands to guide instead of push or ride (dwarves guiding minecarts will ignore traffic restrictions), as well as by [[pasture|pasturing]] domestic animals and preventing the access of other creatures to the tracks. Note that removing the track doesn't reset that tile back to normal traffic priority, so you may wish to manually clean up traffic designation afterward. Also note that bridges that are used as tracks don't have their traffic priority changed automatically (since they're just normal bridges), which could cause dwarves to pathfind normally through dangerous minecart entrances in your fort's walls if you're not careful.

The only <s>fool</s>''dwarf''-proof method is to make the tracks inaccessible. There are several ways to create a track which works for minecarts but doesn't allow creature-traversal; the simplest is perhaps building a [[statue]] on the tracks. Other options include adding single-tile holes (minecarts moving at reasonable speed will jump the gap), vertical drops, minecart-triggered doors, small pools of liquid (4/7 water or 2/7 magma), and hostile creatures overlooking the tracks. For safety, both ends of the track should be isolated, making the dangerous center sections completely inaccessible (though maintenance access can be provided by a locked door).

Danger does not always involve living victims: careless route designation can also result in minecarts careening off tracks or colliding with each other. If this occurs, the [[item]]s may be scattered; this can cause even more hauling jobs than the minecart aimed to eliminate. Even <s>better</s> worse, scattered items, especially [[weapon]]s, can injure passing [[dwarf|dwarves]] or other [[creature]]s; in the words of Toady One the Great, "Accidental grapeshotting of the dining room should be possible now."

Of course, the danger of using minecarts means they can also be [[Trap_design#Minecarts|used as weapons]] by imaginative players.

== Advanced usage and automation ==
Minecart-specific effects are implemented via track stops, rollers and [[pressure plate]]s with "track" condition set. Since all three are considered [[building]]s, they can't be built on the same square (however convenient track stop + pressure plate would be) nor a simple ramp, and are removed by {{k|q}} {{k|x}}.

=== More on Track stop ===
Track stops are constructions that allow further automation of minecart systems via adjustable features such as braking by friction and automatic dumping of contents. They can be built from logs, bars and blocks through {{K|b}} {{K|C}} {{K|S}}; friction amount, dumping toggle and dumping direction must be set '''before''' construction, and these settings can be neither changed nor seen thereafter; however, track stops can be linked to [[pressure plate]]s or [[lever]]s to toggle friction and dumping On or Off (trigger state is inverted: switch On = track stop Off).

If a [[stockpile]] is placed on the tile that a track stop is set to dump to, it can act as a [[Exploit#Quantum_stockpiles|quantum stockpile]] and any items dumped from a minecart that match the storage settings of the stockpile will remain there and accumulate. Normally trackstops are built on top of existing track to operate on moving minecarts, but they can also be used without tracks to create [[Exploit#The_Minecart_Stop|automatic quantum stockpiles]] (see also [[#Step-by-step_tutorial|step-by-step tutorial]]). It is not always desirable to collect ALL of certain items into one quantum stockpile, such as when distributing a material to multiple separate industries. You can link your quantum stockpile to various other stockpiles, ensuring that your dwarves will keep them supplied as necessary. Because quantum stockpiles never fill up like regular stockpiles, it may be a good idea to add a switch to turn them off.

Items dumped from a minecart at a track stop (or dumped by any other means) into open space fall through z-levels until they land on a solid surface. Items falling onto a designated [[stockpile]] will automatically be considered part of that stockpile, even if the stockpile is set to disallow those items (they will, however, be automatically moved to a more appropriate stockpile, if available). Items falling on top of a minecart will '''not''' fall "inside" the minecart. Use with caution; dwarves have fragile skulls.{{bug|5945}}

=== Automated propulsion ===
==== Roller ====
{{Main|Roller}}

A '''roller''' is a [[power]]ed [[machine component]] for the automated propulsion of minecarts. They are built over the top of existing tracks with {{K|b|M|r}}, requiring a [[mechanic]], ''(length/4)+1'' [[mechanism]]s and a [[rope]]. Rollers may also be placed directly on ramps to help pull carts up Z levels. Rollers are very useful to maintain a cart's momentum along long routes, to get them to climb Z-levels without dwarfpower involved, and to get them to reach speeds unattainable by guiding dwarves. These devices are variable-length (1-10), variable-direction and variable-speed ([[Minecart#Numbers_behind_the_scene|see below]]), all traits that can be set at construction time; a roller uses two units of power per tile it is long.

Single-tile rollers transfer power in all four cardinal directions, while other rollers generally only transfer power perpendicular to their activity direction. Longer rollers can also transfer power along their activity direction if built in the correct order, although this can be hard to accomplish and is easily broken. Rollers cannot be powered from above.

Rollers have great acceleration and capped speed. Carts going faster than the roller are unaffected. If a cart moves across an active roller in the direction the roller works and moves slower than the roller's specified speed, the cart will be set to the roller's speed. A cart going against a roller's movement direction will be sent back the way it came (once again at the roller's speed), unless it was moving extremely fast: speed increment of 100000 allows to reverse carts from the full "highest" (50000) speed roller to full "highest" speed back, but ramps can accelerate a cart beyond this. {{cite forum|144328/5702453}}
A cart crossing over a roller perpendicular to its current movement direction will gain the roller's amount of speed in the perpendicular direction without directly changing its forward motion. Without an adjacent wall to constrict its movement, this will typically send a cart off the rails on a diagonal path, completely unable to follow any tracks until it collides with a wall or is otherwise brought to rest. However, if the roller is placed over a track turn and pushes ''from'' the direction of that turn's track, the turn affects carts ''after'' the roller, so they will be forced into the turn rather than derailed in a diagonal direction. {{cite forum|144328/5702453}}

{{diagram|spaces=yes|\
tracks: full:
║ ║
═╗═ ═╢═
║ ║

╢ : roller pushing from W to E
}}
If the roller is powered, carts from ''all'' directions (unless too fast) exit S, because speed imparted by the roller forces carts toward E and ''then'' into the turn.
If not powered, carts from W and N exit S, carts from E and S exit W. Carts above derail speed will ignore the turn, of course.

{{diagram|spaces=yes|\
║ ║
═╗═ ═╟═
║ ║

╟ : Roller pushing from E to W
}}
Carts from the E or W: exit W.
Carts from N: derailed diagonally, exit SW.
Carts from S: derailed diagonally, exit NW.

Rollers affects carts on a track - if placed on a floor or ramp without any tracks, they are ignored. Depowered rollers are also ignored, friction is determined by the tiles underneath.

Because of their one-way nature, rollers are unsuitable for most two-way minecart tracks (unless you set gears toggling roller A->B off while toggling A<-B rollers on). However, a minecart set to be ''guided'' is not affected by rollers at all{{cite forum|109460/3286235}} — this allows a one-way track to be used in both directions. In addition, unpowered rollers do not affect minecarts.

Care must be taken in [[glacier]]s and other extremely cold [[biome]]s, since rollers (and the machinery used to power them) will not operate when constructed on natural [[ice]] floors.

==== Impulse ramps ====
Carts can be given momentum without rollers or changing z-level through a phenomenon called "impulse ramps". A track ramp which is connected both to a wall and to a floor will ''always'' accelerate a cart towards the connected floor tile, no matter where the cart enters the tile from. This means carts can be accelerated as though dropping z-levels, even if the cart doesn't actually change z-level at all. If a track ramp faces three directions such as ╩, then two of those directions need to be facing walls for the cart to be accelerated towards the remaining direction.

Example of straight impulse acceleration:

{{diagram|spaces=yes|\
▒▒▒▒▒▒▒▒▒▒ ▒▒▒▒▒▒▒▒▒▒
═▲▲▲▲▲▲▲▲▲▲═ ═╚╚╚╚╚╚╚╚╚╚═
▒ : Wall
═ : Normal track
▲/╚ : N/E Track/Ramp
}}

If a cart enters from the left, it will speed up on every track/ramp and exit to the right going very very fast - more than one tile every step. If it enters from the right then it will bounce back impulsed by the ramp if it's going slow enough.

As another oddity, carts coming from ramps will in some cases "teleport" through most of the next tile. This is called the "checkpoint effect", and is explained in detail in the Physics section, below. This negates the deceleration of the next tile if it is a ramp "angled" in a different direction. You can just make an upward spiral alternating impulse ramps and regular upward ramps. It takes no power, is quick and cheap to build, requiring only channeling and track carving, and the cart goes up fast, but not so fast that it launches its contents.

Example of an impulse elevator:

{{diagram|spaces=yes|\
z +0 z +1 z +2 z +3
░░░░░ ░░░░░ ░░░░░ ░░░░░
░╔░░░ ░▼╚╗░ ░░▼▼░ ░░░░░
░╝░░░ ░▼░░░ ░░░╔░ ░░░▼░
░▼▼░░ ░░░░░ ░░░╝░ ░╚╗▼░
░░░░░ ░░░░░ ░░░░░ ░░░░░

░ : Wall
╔,╚,╗,╝ : Track/Ramp
▼ : Down Ramp (empty space)
}}

Note that this impulse elevator, due to the checkpoint effect and upward curved ramp effect, will not actually result in carts traveling straight up the ramp. They will lose speed, bounce off a ramp, then be accelerated back into the spiral after a 9-turn delay on both tiles on the floor where they are stopped. This is because the checkpoint effect allows carts to travel up the ramps in a single turn, but also prevents the impulse ramps from adding acceleration unless the cart is slowed to staying on the ramp for more than one turn. Initial acceleration will carry the cart up a variable number of floors before this effect occurs, but this bouncing back and forth will occur every 5 z-levels after the first time the cart stops. When the cart ''is'' traveling upwards, it will pass every tile at a rate of one tile per turn regardless of its actual speed, due to the checkpoint effect. In tracks with only a single cart, this is negligible, but when multiple carts are on the same track (such as when you place multiple carts on a magma cart lift) this can cause collisions which derail carts or cause other unexpected or undesired behaviors.

The following impulse ramp (while larger) should alleviate these problems by using a straight ramp to go upwards, preceded by an impulse ramp to exploit the checkpoint effect and negate up ramp costs. Corners still decelerate carts, so the cart will tend towards a velocity of 72k, which is derail speed. Derail speed breaks (see Controlling Speed, below) may be necessary at the top.

{{diagram|spaces=yes|\
z +0 z +1 z +2 z +3
░░░░░░ ░░░░░░ ░░░░░░ ░░░░░░
░░░░░░ ░╔╔═░░ ░░▼▼╗░ ░░░░░░
░║░░░░ ░▼░░░░ ░░░░╗░ ░░░░▼░
░╚░░░░ ░▼░░░░ ░░░░║░ ░░░░▼░
░╚▼▼░░ ░░░░░░ ░░░░░░ ░░═╝╝░
░░░░░░ ░░░░░░ ░░░░░░ ░░░░░░

░ : Wall
║,═,╔,╚,╗,╝ : Track/Ramp
▼ : Down Ramp (empty space)
}}

Also, if you want to have a cart following a below-derail speed, the following track works well:
{{diagram|spaces=yes|\
z +0 z +1 z +2 z +3
░░░░░ ░░░░░ ░░░░░ ░░░░░
░░░░░ ░══░░ ░▼▼║░ ░░░▼░
░║░░░ ░▼░░░ ░░░║░ ░░░▼░
░║▼▼░ ░▼░░░ ░░░░░ ░░══░
░░░░░ ░░░░░ ░░░░░ ░░░░░

░ : Wall
║,═ : Track/Ramp
▼ : Down Ramp (empty space)
}}
In this elevator, the cart collides with the walls in the corners, but then realigns on the ramp, picks up speed, checkpoints through the next ramp, and slams into the next wall. It is slower (10 ticks per floor) but produces reliable speeds, and will exit the impulse elevator at little more than push speeds.

A sort of opposite effect to impulse ramps also exists: ramps lacking the proper "up" and "down" connections are treated as flat track, even if they actually go up or down z-levels. This allows building "anti-impulse" slopes consisting entirely of ramps only connected up, which a minecart can travel up forty levels and more, needing no more than a single push.

=== Controlling traffic ===

==== Switching ====

As constructions or tile features, [[door]]s and other furniture can be built on tracks. A [[door]] or [[floodgate]] can be turned on or off by a [[lever]], effectively controlling the flow of automated minecarts. This may be <s>dangerous</s> [[fun]], however.
{{diagram|spaces=yes|\
->
A ════┤≡════ B
┤ : roller pushing to East
≡ : door
}}
The roller pushes the cart east, but until the "departure condition" is fulfilled, the door remains closed and blocks the path.

[[Bridge]]s can also act as tracks, but only if they're lowered or not retracted. This property can enable levers to turn tracks on and off. However, care should be taken to ensure that such bridges are never operated while a cart is on top of them, as the cart will be flung off the track. It's worth noting that it's often faster, and cheaper, to construct large bridges than long sections of constructed track.

A powered track switch can be constructed by building an "inverted" corner as illustrated below.
{{diagram|spaces=yes|\
B B
║ -> ║
║ ║
════╚═══ ════├════
A C A C
├ : roller pushing to West.
}}

If the cart is pushed East from the stop at 'A' while the roller is activated, it will arrive at 'B'. If the roller is not running, it will arrive at 'C'. The switch works by the roller first reversing the incoming cart's movement and the cart ''then'' following the track corner.

This switch is very reliable, reacts instantly to on/off signals, and carts of any speed can be switched by this design, although very fast carts will require rollers that are several tiles long, up to three. The requirement for power can be inconvenient or impractical. Non-powered solutions may use controlled derailment, or a connecting bridge.
{{diagram|spaces=yes|\
B ╥
║
║
╞════╝ ════╡
A D C
}}
Here the track between A and C is not continuous. The only continuous track is A->B, with a corner (not a T section). Fast moving carts will tend to derail at D and rejoin the track to C. Placing a door at D will prevent the derailment, so the cart continues to B. The door is operated by mechanisms elsewhere (typically, a lever, but some fun can be had with pressure plates).

Since it depends on derailing, this switch requires a very fast cart, faster than what can be achieved with rollers alone. To gain sufficient speed, a cart must be accelerated further, usually by descending several levels or through impulse ramps. The high speed makes the cart much more dangerous and harder to control.

If carts are moving too slowly to derail at the corner, a retractable bridge may be used as a connector between A and C.
{{diagram|spaces=yes|\
B╥
║
║
A╞════bbb════╡C
}}
The bridge must overlap the corner. Bridges behave like a track crossing, allowing carts to pass in a straight line. When retracted, the corner reappears, so the carts will continue to B. Bridges take 100 steps to react to a signal, necessitating rather long "lead times" when switching tracks via bridge.

As mentioned above, special care must be taken to make sure the bridge doesn't change state while the cart is passing over it. Retracting bridges will throw the cart, causing it to stop dead. Raising bridges can even crush the cart.

==== Controlling Speed ====


Minecarts can reach extremely high speeds, especially when descending multiple Z-levels. A minecart will derail at a track corner if its speed exceeds 0.5 t/st (tiles per step), '''unless''' the route in the direction of travel is blocked:

Will derail at > 0.5 t/st:

{{diagram|spaces=yes|\
in ══╗ -> derailing
║
out
}}

Will not derail at > 0.5 t/st:
{{diagram|spaces=yes|\
in ══╗O
║
out

O : wall/column.
}}

This behavior can be used to build a "speed limiter", that will ensure that when a minecart exits it is traveling below derail speed:
{{diagram|spaces=yes|\
░░░░ ░░░░░ ░░░░░
in ═╔═╗░ ░╔S╗░ ░╔S╗░
out ═╬═╝░ out ═╗═╝░ out ═╗═╝░
░╚S╝░ ░╚═╝═ in ░╚S╝░
░░░░░ ░░░░ ║░░░
in
░ : wall
S : Track Stop (High Friction or lower)
}}
If the minecart is traveling below derailment speed, it will not be affected; if above, will be slowed down and checked again. Granted, you could do the same just with track turns, but it may take a lot of turns and time.

Since all the derailings, bounces and ramps can impart a sideway component of speed small enough to start visible drift many tiles away (say, [[Fun|in the middle of a bridge]]), track turns have one more use: forcing the carts to move strictly along the grid directions. Carts passing a turn below derailing speed convert one component of velocity into another, thus eliminating the drift.

=== Loading liquids ===
[[Water]] and [[magma]] can also be loaded into minecarts by submerging them to a depth of at least 6/7 while standing still or moving at speeds of at most 10000. Loading fluids onto minecarts can be difficult because the added friction provided by fluids can stop a cart in a submerged tile. Curiously, filling a minecart with magma does not injure a dwarf ''riding'' it. A minecart will hold enough fluid to increase the depth of a single tile by 2. This amount is listed as 833 units, which weigh 459Γ (water) or 999Γ (magma). An iron or steel cart filled with magma weighs 1313Γ, while an adamantine cart filled with magma weighs 1007Γ. Since you need a minecart above the liquid's level, possible arrangements may include pressure-activated sluices, rollers (with magma-safe chains for magma), pouring from above to "submerge" it briefly on the same level and drain excess away (dig deeper and leave a vaporizer, though if you could have power for rollers, may as well use a pump) and exploits with ramps (not necessarily impulse ramps, "same height" passing dip does it).
The liquids can be dumped by a constructed track stop.

== Quirks ==
This little quirk concerns dwarf-managed minecarts. If a track which was previously open becomes blocked (ex. flipping a switch connected to a floodgate you've built on the track to raise it) and the conditions for departure are met, instead of refusing to ride/guide the minecart or ride/guide it until it reaches the obstacle, the dwarf will pick up the minecart off the tracks and haul it to its scheduled destination on foot. If the distance is long enough and the weight of the cart heavy enough (due to being filled with heavy items such as stones), the dwarf may drop the cart because of fatigue/hunger/thirst before reaching the destination. This will cancel that vehicle setting job and make another dwarf come by and attempt to haul the cart to the nearest appropriate stockpile where another dwarf will pick up the cart and attempt to haul it to its initial stop. If the stockpile is far enough from initial stop, this second dwarf who is attempting to place the minecart on its tracks may also drop the minecart out of fatigue/hunger/thirst creating a loop that will go on until a dwarf with enough endurance manages to place the minecart where it belongs.

In fact, it seems dwarves are more than happy to attempt to carry a minecart from one stop to another even if just waiting until the track is open again would be the more sane option.

Dwarves will also carry a minecart to its next stop if the direction specified is incorrect (or invalid). This can often occur when using the default departure settings and forgetting to set the direction of each condition.

Dwarves can admire buildings while riding mine carts. Dwarves will not fall asleep during a ride (at least not from being drowsy). If riding on a continuous powered track loop, the dwarf will die of dehydration/starvation as they can not jump off to get sustenance{{cite forum|109460/3377228}}. Dwarves riding in submerged minecarts will gain experience in [[swimming]].{{cite forum|129889}}

Tracks block wagon access to trade depots, unless they're on a ramp. [[Bridge]]s can also be used, as they function as tracks but do not block wagons.

== Physics ==


Minecart physics depend greatly on the departure mode set in the route stop conditions.

When set to "Push" or "Ride", minecarts will move according to the regular laws of momentum, gaining speed when going downhill, losing it slowly due to friction when on a flat plane, and more quickly when going uphill. In these modes, minecarts will move in a straight line until they either are brought to a stop by friction or an obstacle, or until they encounter a turn. A minecart will roll straight past "blocked" ends of T-junctions or track ends, they have no power to restrict a cart's movement. The cart's behavior is largely independent of the weight of its contents (including fluids and dwarves): heavily loaded carts gain more momentum when accelerating, but this only plays a role in collisions: a heavy cart gains just as much speed and is as easy to stop as a light one. In either case, dwarves can not push nor ride an unpowered cart up a ramp, bouncing back the direction it came. At best, this is a waste of time; at worst, it will give your cart-pushing dwarf a [[fun|fun surprise]]. To solve this, the player can either use Rollers (see below) or set the cart to be Guided.

The difference between "Push" and "Ride" is whether the dwarf will go along with the cart or not.
{{DFtext|Push}}: the dwarf will give the cart an initial push, not enough to go up a ramp, but enough to go some way along flat track, and the dwarf will remain at the first stop, ready for a new job.
{{DFtext|Ride}}: the dwarf will give the cart the same initial push and then hop aboard the cart riding with it to the next stop.
{{DFtext|Guide}}: minecarts seem to ignore all laws of physics. That is:
*Ignore the weight of any and all items inside. Therefore:
**Move at the speed of the dwarf that is guiding them. It is thus recommended to pick the most [[attribute#Agility|agile]] of your dwarves for cart-guiding tasks.
*Ignore working rollers.
*Will ''not'' collide with other guided carts even when a full frontal collision would be expected.
*Will go up ramps like nobody's business.
This is therefore the recommended method of transport for simple non-powered rail systems, despite it diverting a dwarf from other, potentially more important tasks.

Some samples with behavior:
{{diagram|spaces=yes|\
A <-> B A <-> C A <-> B
B B B
║ ║ ║
A══╝ A══╩══C A══╬╗
You can only go A->B ╚╝
Works when the cart Works
is in Guide mode.
}}
In the second example above, a cart "pushed" from B will go over the junction and roll off into the unknown south.

=== Numbers behind the scene ===

According to early research by '''expwnent'''{{cite forum|112831/3536975}}:

The minecart has 3 variables for velocity. Velocity can be thought of as tiles per 100000 ticks, so a velocity of one hundred thousand means a cart travels one tile per tick. By going down a large number of ramps, a maximum velocity of 270,000 can be reached, which presents the limit for most practical applications. Short bursts of (much) higher speeds are possible through carefully planned collisions of high-speed carts {{cite forum|137557/5145499}}. (See [[#Perfectly Elastic Collisions|Perfectly Elastic Collisions]].)

Every tick the cart adjusts sub-tile position units by the amount of their velocity, as well as adjusts velocity depending on current tile (speed is reduced by the "friction" of the tile, or accelerated if going "down" a ramp). On flat (non-ramp) tiles, the cart will move to the next tile when the sub-tile position goes either above 100,000 or below 0, (or several tiles if velocity is over 100,000,) and 100,000 is either added or subtracted to sub-tile position to restart the count to the next tile change.

Since most deceleration and acceleration is applied per step, with the notable exception of corners, a cart going at twice the speed of another one can cover about four times the distance in a straight line, but only twice the distance along a winding track with very many corners.

A push will teleport a cart to the beginning of the next tile (NOT the middle!) in one tick with 19990 speed (10 speed is lost due to track friction), while a roller will give a cart the roller's set speed, and it will start to accumulate regular track friction past the middle of the roller tile. Some track features will affect a minecart when it is past the middle of the previous tile: entering a ramp or a hole/drop will happen when the cart has left the middle of the previous tile, and the ramp will gain additional distance unit depending on the leftover units from the previous tile. When a cart leaves a ramp it will emerge after one tick in the middle of the next regular tile, so its entry coordinate is "50000-speed+friction". Rollers also affect the speed of minecart from the middle of the previous tile.

Friction of tiles:
{| class="wikitable"
|-
! Tile
! Friction
! Comment
|-
| Tracks
| 10
|-
| Ground/Floor
| 200
|-
| Unusable ramp
| 10
|-
| Upwards ramp
| 4910 (10+4900)
|-
| Downwards ramp
| -4890 (10-4900)
|-
| Roller
| ±100000 (but capped by the set speed)
|-
| Corner track
| 10
| Speed reduced by 1000 upon leaving the corner tile
|-
| Track stop (highest)
| 50000
|-
| Track stop (high)
| 10000
|-
| Track stop (medium)
| 500
|-
| Track stop (low)
| 50
|-
| Track stop (lowest)
| 10
|-
| Water 1-6
| Additional (WaterLevel - 1) * 100
| rowspan="2" | [[#Skipping|See Skipping]]
|-
| Magma 1-6
| Additional (WaterLevel - 1) * 500
|-
| Empty space
| 0
|}

Water of depth 7/7 provides a friction of about 10000 per step, as does maximum-depth magma. This higher friction may not apply to very slow-moving carts.

Impulse sources:
{| class="wikitable"
|-
! Feature
! Speed
|-
| Push
| 20000
|-
| Roller lowest
| 10000
|-
| Roller low
| 20000
|-
| Roller medium
| 30000
|-
| Roller high
| 40000
|-
| Roller Highest
| 50000
|-
|}

Note, again, that nearly all of these values are applied ''per tick'', rather than ''per tile''. The exceptions are curves, which is 1k deceleration per direction change at the half-way point of the tile, and rollers, which ''set'' the speed every tick. This makes rollers particularly useful in high-deceleration situations, such as underwater, but require that ''nearly every tile'' in such high-deceleration situations have a roller.

A cart heading up a ramp can experience deceleration on multiple ticks, (and stays on the tile more ticks the slower it is going, resulting in greater deceleration,) and as such, a cart leaving a "Highest Speed" roller with 50k velocity will not be able to climb 10 consecutive straight ramps, since they are ''not'' "5k deceleration each". In fact, the first ramp not on a roller will be -15k velocity, and, depending slightly upon other factors of "remainder" x position, the second may completely cancel forward momentum, and send it rolling back down, where it will bounce off the roller repeatedly. Using rollers to power carts up ramps reliably requires rollers every other un-rollered ramp. Fortunately, rollers can be built upon ramps, themselves, which allows for rollers to only need to be built every other floor. (Exploiting the [[#Checkpoint Effect|checkpoint effect]] can allow one to bypass this requirement.)

=== Sub-tile Positions and Velocity ===
Carts store six values that are unique to them. Three sub-tile position values, and three velocity values. (X, Y, and Z.)

Note that the Z position and velocity only matter when a cart is in flight. (See [[#Falling|Falling]] and [[#Cart Jumps|Cart Jumps]].)

Each non-ramp tile is functionally composed of a value between 0 and 100,000, with a "centered" cart sitting at the 50,000 point in all three directions. When a cart has velocity, it is added or subtracted from the current position every tick, and then a friction force is applied to the cart.

In essence, every sub-tile position unit is a decimal value of a tile, 0.000001 tiles, in a game that largely prefers integer values.

When carts move beyond the maximum or minimum value of a tile, they physically move a tile on the map, and start at the far end of the sub-tile position the next tile. (I.E., traveling West, a cart that starts a tick at 15,000 X sub-tile position and has an X velocity of -20,000 would move to -5000 X sub-tile position, which is out of bounds for that tile. As such, it will travel one tile West, and start the next tick at 95,000 X sub-tile position. It will also lose 10 velocity in that tick due to friction with the track if it is on a track, or 100 velocity if it is on regular ground, or no velocity if it is airborne.)

Ramp tiles are longer, approximately 144,000 in the direction where it "slants downward", (to approximate a 45 degree slope, it is square root of two times longer,) and centered at 72,000. Because of this, a cart with no velocity dropped from a hatch will land at the center of a tile, at position 72,000, and 72,000, and will start rolling in the ramp's "downward" direction, picking up the ramp's acceleration (4890 per tick in the direction of the ramp's "downward" direction) every single tick, then moving that sub-tile amount every tick. (This results in a cart that takes 5 ticks of acceleration to leave its ramp - 6 ticks overall - and to leave the ramp with about 23k velocity, slightly more than a push.) When it enters another ramp ''facing the same direction downwards'', a cart will start at the 0 or 144,000 position, and have twice as far to travel. This means that if a cart enters a ramp from the side, it will gain twice the momentum of simply starting at the midpoint of a ramp.

Note that passing from one direction of ramp to another or to flat terrain causes unintuitive behavior, "teleporting" to the midpoint of another tile in what is called the "[[#Checkpoint Effect|checkpoint effect]]".

Note, however, that sub-tile positions are carried over from tile-to-tile. This separate tracking of velocity and position between X and Y can lead to problems with diagonal motion:

{{diagram|spaces=yes|\
z0 z-1
▒║▒ ▒▒▒
═▼═ ▒╬▒
▒ ▒ ▒║▒
▒ : Wall
═, ║ : Track
╬ : Track and Ramp
}}

If a cart is passing West-to-East over this setup, the valid ramp to the South will apply "Southward" acceleration to the cart (-Y velocity) as it passes through the ramp tile. Assuming it only spends one tick in that tile, it will still have gained about -5k Y velocity, which will still apply motion Southward. If the tracks continue straight for another 11 tiles, it will have accumulated enough Southward motion to try to move a tile South, even if all tracks are facing East-West.

'''Non-curving tracks do not correct this motion'''.

They don't "tip back over" without adjustments in the track. Any value of sideways motion on tracks larger than 990 will lead to a derailment. (Lower values will be nullified by friction before they are enough to lead to derailment, but there is currently no way to apply such a small amount of velocity.)

If the tile to the South is a wall at that point, it will be considered a collision with a wall that ''halts all motion''. If the tile is open, it will generate a diagonal track derailment that will send a cart flying until it strikes a wall, at which point it will not re-rail itself. In almost any circumstance, this is undesirable behavior.

The only way to appropriately deal with this is to either cancel out this behavior with an equal amount of acceleration in the opposite direction, or to take a curve.

Note, again, that sub-track position is saved in both directions, so when a cart approaches a curve, it will already have a shorter or longer distance past the curve when it makes the turn.

Curves are applied "halfway through" a tile. If a cart is moving East, and approaches a North-East track at 20k velocity, and friction is eliminated for the purposes of a cleaner demonstration, then when it enters the tile at sub-tile point 0 X, and 50k Y at the start of a tick, it will then move 20k East (+X) the next tick, and be at 20k X sub-tile position, and 50k Y sub-tile position. Next tick, it is at 40k X sub-tile position, and 50k Y sub-tile position. The next tick would take it to 60k X, but that's past the halfway point, so it stops at 50k, turns (and thus loses 1k velocity, but translates the rest from X-velocity to Y-velocity) and travels another 10k. It is now at 50k X sub-tile position, and 60k Y sub-tile position. Next tick, it travels at 19k velocity North, and so moves to 50k X sub-tile position, and 79k Y sub-tile position. Then in two more turns, it leaves to the North.

In the case of diagonal motion due to having velocities in X and Y at the same time, it is critical that the direction the cart is heading in reaches that halfway point in a curve before the cart leaves the track off its sideways velocity direction. If it does so, all sideways velocity is lost, as forwards velocity ''overwrites'' sideways velocity in a curve. If, in that example in the paragraph above, the cart entered at 0 X sub-tile position with 20k X velocity, and 40k Y sub-tile position and -1k Y sub-tile position, it would take that "curve" (or rather, redirection of velocity) on the third turn, while it is at 38k Y sub-tile position to start with, and then move to 47k Y sub-tile position at the end of that tick. It would then move to 56k Y sub-tile position in the following turn, and take 3 turns, rather than just 2, to clear the tile.

But, most importantly, it would be centered in the X sub-tile position, and with the negligible difference of an extra tick, all sideways velocity could be safely ignored.

There are two common ways to gain sideways velocity: Rollers facing perpendicular to the cart's travel path (which, as covered above, are almost always a bad idea, as it is easier to push ''against'' the travel direction of a cart into a curve, which redirects all velocity in the new direction,) and [[#Corner Ramp Derail|corner ramps]], and require a curved track to compensate for sideways velocity within a few tiles.

=== Track Direction Irrelevance ===
Carts that are traveling independently, (that is, not guided,) only care that tracks ''are'' on the tile, not which direction the tracks actually move. Tracks respect only curves (with two exits) and ramps.

This means, for example, that the following tracks, when a (non-guided) cart travels from West-to-East, are functionally identical in effect:

{{diagram|spaces=yes|\
A════════════B A╬║╚╔╣╩╦╠╥╨╞╡B
}}

This is because so far as the cart is concerned, only valid ramps and curves with two exits where there is no exit in the path they are traveling matters.

Hence, if a minecart encounters the end of the track or a T junction with no "exit" in its movement direction, it will simply leave the track and continue on its course in a straight line until it encounters an obstacle, slows to a stop, or encounters another track even if the tile at which it joins the new track instantly sends it around a corner.

In fact, in a track designed for pushes or rides, a "║", a "╦", a "╬", and a "╥" are ''only different in appearance'', and are ignored by an unguided cart, which will continue in its current direction, regardless of the track. For any purpose but guided tracks, ''only curves and ramps matter at all''.

Tracks like T-junctions, however, ''are'' respected by dwarves guiding carts, who will lift and carry carts if they cannot find a valid track to their destination, and can choose to follow any orthogonal direction at a four-way junction in much the same way as they normally pathfind. What this functionally means is that T and four-way junctions ''only guide dwarves hauling a cart, not carts, themselves''.

Carts only check for curves when they are halfway through a tile. When they get there, they look to see if their path has no exit. (That is, if it is traveling East, it checks if there is an East exit.) If there is, it ignores all other track directions, and keeps traveling. If there is not, it checks to see if there are only two exits to the track, and if one of those directions was the direction it "came from". (That is, if traveling West from the East, it checks if there is a valid exit to the West, and if not, if there is an East exit and EITHER a North or South exit.) If there is not, it ignores the track anyway, and keeps on traveling as though it were still on track.

If there is a curve the cart will respect, it checks for derailment. Carts derail at a speed whose exact number is currently unquantified, but is over 50k. Carts at this critical speed will then check for blockages of their forward path. If there is an obstacle to their path, which may be a wall or even furniture or buildings like a door or impassible workshop tile, they will not derail and respect the curve, anyway. Derailing carts do not "[[#Cart Jumps|jump]]" unless they hit completely untracked tile or an invalid ramp, but simply ignore the layout of the tracks entirely. With invalid ramps, this means not respecting the ramp, and likely results in collision with a wall, zeroing of all velocity, and a cart that requires manual retrieval.

If the cart is traveling at a speed that will not derail, or is forced to turn by a supporting wall, it will subtract 1000 from the "forwards" velocity of the cart, and redirect all forward velocity to the direction of the curve. This change in the direction of velocity ''overwrites'' any "diagonal" velocity, which can prevent diagonal velocity derailments, but any perpendicular velocity is not preserved, and is instead discarded.

=== Valid and Invalid Ramps ===
Ramps are functionally defined for cart purposes as being a tile which exerts an acceleration force upon its "downward slope", and which allows connection to tracks a z-level above or below. This downward slope requires a cart to have one ''and exactly one'' carved exit to the tile that is the "bottom" of the ramp. Ramps accelerate carts in this "downward" direction (possibly leading to [[#Corner Ramp Derail|diagonal movement]]), and the deceleration of an "uphill" ramp is actually just the acceleration being applied against the direction of a cart's movement.

This is where players can find an exploit in the behavior of ramps - if there are ''two'' "downhill" exits to a ramp (such as a "T junction" on a ramp where only one exit faces a wall), then the ramp provides no acceleration ''or'' deceleration, allowing carts to travel up ramps without any loss of momentum except for the standard "flat track" deceleration, because as far as the cart is concerned, the track ''is'' flat. (A T junction is also not a curve, so the track is considered flat and straight no matter what direction the cart is traveling.)

Similar effects can be achieved when there are ''no'' "downhill" exits to a ramp. This may be the case if you have, for example, an East-West track with a one-tile channel with a ramp in it. The cart will travel through the "dip" with no change in velocity. It can also be the case if you abuse the [[#Track Direction Irrelevance|Track Direction Irrelevance]], and set only exits ''up'' the ramp, and none leading ''down'' the ramp. For example, if a cart is traveling from West to East up a slope, only carving East exits on each tile of ramp will make the cart travel up the ramp, and then recognize the tile it is on as being a "flat" tile, thus ignoring any deceleration from traveling uphill.

Note that this effect only reliably occurs at below-derail speeds as the cart will treat the ramp as an invitation for a ramp jump otherwise. (This almost always results in a collision with a wall that will stop forward progress.)

=== Falling ===
When falling, a minecart appears to cause no damage upon collision, possibly to allow cart "stacking" across Z-levels.{{cite devlog|2012|04|06}} A dwarf riding in a minecart that is dropped multiple z-levels suffers normal fall damage. Minecarts can fall through up/down stairs.

While airborne, carts do not feel the effects of friction in any horizontal direction, and will continue until they strike an obstacle. Carts that land on tracks instantly re-rail themselves regardless of track directionality.

Falling carts accelerate similarly to the way that a ramp will accelerate a cart in a special z-only velocity that only applies to airborne carts. (Actually, acceleration due to gravity in freefall seems curiously slightly ''slower'' than ramp acceleration.) Ramp acceleration, while it logically should be partially z-directional, is only recorded as x- or y-directional, and there is no translation of z-directional velocity upon landing. Landing carts zero out their vertical velocity upon landing, even when landing on ramps, although carts that had horizontal momentum while falling preserve it.

This means a cart falling (from a hatch, thus with no horizontal speed) onto a track ramp is accelerated as if starting from the middle of the ramp - i.e. to the same speed, no matter how many Z-levels it was dropped, vertical velocity is negated. {{cite forum|144328/5701211}}

Carts falling onto a floor can, however, cause damage to creatures ''one tile below the floor''. This can be used in an [[exploit]] called a "thumper", where carts are caused to repeatedly fall on a floor above an entrance to the fort, inflicting significant damage (as though it were a collision) on those below the cart.

=== Cart Jumps ===
Carts that cross off of "up" ramps relative to their current direction of travel, which do not have a ceiling above them, are traveling above derail speed, and do not have valid ramp track before them can translate a portion of their horizontal velocity into vertical velocity, causing a cart to be projected into the air until vertical velocity is negated and overcome by the gravitational acceleration. Because downwards acceleration is applied per-tick, this creates a reasonable facsimile of the parabolic motion of an actual object rolled up a ramp and launched with significant speed.

{{diagram|spaces=yes|\
z0 z0 hiding ramps z+1 A z+1 B (hidden ramp)
▒▒▒▒▒▒▒▒▒▒▒▒ ▒▒▒▒▒▒▒▒▒▒▒▒ ▒▒▒▒▒▒▒▒▒▒▒▒ ▒▒▒▒▒▒▒▒▒▒▒▒
═▲▲▲▲▲══▲▒▲═ ═╚╚╚╚╚═══▒══ ▼▼▼▼▼ ▼═▼ ▼▼▼▼▼ ▼╚▼
▒ : Wall
═ : track
▲ : Ramp
}}
In this diagram, if there is no ceiling above it, the track in z+1 A will launch its carts airborne when they travel across the ramp. z+1 B (with a ramp on the tile on the hill) will not launch the cart. The cart would also not be launched with ''any'' valid ramp, even if it does not travel in an appropriate direction, such as North/South (which the cart will ignore, as it is not a curve, anyway, although it may produce acceleration that may cause diagonal movement.)

Carts that are traveling at derail velocity will also start "jumping" from the track if it hits an un-tracked tile, flying over and ignoring any tracks until it is ready to land. Carts that land upon tracked tiles re-rail themselves, and clever designers use this feature to jump over curved track sections in one direction or another. (Retracting bridges over untracked tiles can cause jumps or not cause jumps depending upon the status of the bridge.) Minecart speed must be carefully regulated to ensure reliability of jump length.

Hitting untracked tiles at around 70k velocity creates a vertical component to acceleration that allows for jumps of around 6 (horizontal) tiles that do not actually leave the z-level the cart is on, but which do apply z-direction velocity on the cart, as per falling.

Carts that approach a downward slope at a high enough velocity will also make a jump, (or rather, ignore the ramp and fly forwards) but will not do so if the [[#Checkpoint Effect|Checkpoint Effect]] is exploited through an impulse ramp before the actual downhill as the impulse ramp "tricks" the cart into thinking it has already started going downhill. The cart will also not fly off the ramp if there is a wall and ceiling preventing any motion but going down the ramp.

=== Skipping ===
If a minecart is moving fast enough, it can skip over [[water]] or [[magma]], making splashes of [[mist]] (or [[magma mist]]) as it attempts to move on them horizontally. This horizontal movement is independent of the minecart and its content's [[weight]].

Skipping causes significant friction on the cart, and even a cart going at max speed from ramps can only make about 50 tiles without requiring re-acceleration. (Carts that decelerate enough that they do not trigger the skipping effect will, of course, sink.)

=== Corner Ramp Derail ===

Corners on upward ramps can cause diagonal movement, forcing a derail even if the cart has a wall next to it, which will force a stop when it touches a wall that forces dwarves to manually reset the cart.

This is caused by the fact that a cart, after turning the bend in the track halfway through the length of the tile, will still "accelerate down", which is now perpendicular to the movement of the cart, causing acceleration to occur in two directions. (Down corner ramps do not have this problem, as when they pass the halfway point, all perpendicular motion is added to forward motion, and after that curve, all downward acceleration is in the forward direction.)

There are two fixes to this problem. One is to simply not put corners on up ramps. The other is to take advantage of the [[#Checkpoint Effect|Checkpoint Effect]], by making a ramp (possibly including an impulse ramp) one tile in front of the ramp to make it skip through most of the tile before sideways momentum can be built.

=== Checkpoint Effect ===
The checkpoint effect, [http://www.bay12forums.com/smf/index.php?topic=144328.0 explained in depth by Larix], is an odd and highly exploitable feature of ramps where minecarts "teleport" through the next tile of track, ignoring nearly all minecart physics (except that they stop at all walls or other obstacles and only respect curves with no backing wall and invalid ramps if they are below derail speed) and passing through that tile in just a single tick, and into the next tile at the halfway point.

This effect occurs when a cart leaves a downward ramp for any other direction of tile. (This includes ramps which accelerate in different directions, even a ramp which goes from accelerating East to accelerating North due to a bend in a chain of standard down ramps in a curve.) This allows, for example, two valid straight ramps directly next to one another with a cart dropped onto one or the other with no momentum to have the cart pick up acceleration going "down" the ramp as normal, but then flying up through the "up" ramp it travels into with no loss of momentum, as though it had come from an impulse ramp. If the two ramps had at least one space of distance between them, and then a cart were dropped in, the cart would instead "rock" back and forth between the two ramps.

This seems to be because ramps have a slightly longer length than regular tiles - 144,000, rather than 100,000 distance. When this "snaps back" after a ramp, it seems to project the cart suddenly further along the track, making it jump a tile ahead even when otherwise moving at relatively low speeds.

This [[bug]] is the cause of a ''wide array'' of unexpected behavior among people who do not take this bug into account. It causes derailments or failure to climb up seemingly valid impulse elevators. In general, it makes a system that behaves extremely counter-intuitively, and operates ''any time a cart encounters a valid ramp''. At the same time, when its effect is accounted for, it is highly exploitable: It causes "perpetual motion devices" using no power when two opposing ramps are placed next to one another, since the "uphill" effect of the opposing ramp is ignored, preventing deceleration.

Another useful thing to note about this exploit is that carts traveling at no less than 72,000 or so speed (enough to travel half a ramp tile in a single tick) can travel through every tile in just one tick at no change in velocity as long as the tiles alternate between impulse ramp or actual down ramp and any other tile type. The cart checkpoints through the non-down-ramp tiles, and can pass through the (impulse) down ramp tiles in a single tick, before they can actually start gaining momentum.

{{diagram|spaces=yes|\
▒▒▒▒▒▒▒▒▒▒ ▒▒▒▒▒▒▒▒▒▒
═▲═▲═▲═▲═▲═ ═╚═╚═╚═╚═╚═
▒ : Wall
═ : Normal track
▲/╚ : N/E Track/Ramp
}}

If the cart enters from the West at less than 72,000 speed, some of those ramps will cause Eastward acceleration.

This means that an impulse ramp not contiguous to other impulse ramps has a top speed of around 75k:

{{diagram|spaces=yes|\
▒▒▒▒▒ ▒▒▒▒▒
▒╔═╗▒ ▒╔═╗▒
▒╚▲╝▒ ▒╚╗╝▒
▒▒▒▒▒ ▒▒▒▒▒
}}
This setup makes a cart that travels clockwise at a speed that fluctuates around 75k velocity. If the cart has more than 72k velocity, it fails to accelerate in the ramp, as it leaves the ramp in a single turn due to checkpointing to the halfway point. After that, the curves sap 1k velocity, and every tick saps 10 velocity.

Two contiguous impulse ramps with a same-facing "downwards slope", however, do not suffer the checkpoint effect in the second tile, giving functionally triple the space to accelerate. This means it will add velocity (at the standard rate of 4.9k per tick) up to a maximum speed of 216k.
{{diagram|spaces=yes|\
▒▒▒▒▒▒ ▒▒▒▒▒▒
▒╔══╗▒ ▒╔══╗▒
▒╚▲▲╝▒ ▒╚╗╗╝▒
▒▒▒▒▒▒ ▒▒▒▒▒▒
}}
This example results in a cart moving three times as fast as the previous cart.

Three successive ramps results in the highest attainable speeds.

In practical terms, this means that only consecutive ramps should be used for high acceleration, but singleton ramps can be used to have speeds that are somewhat regulated.

=== Stacking ===
If a minecart lands on top of another minecart, they may form a stack, with the upper cart on the z-level above the lower. Subsequent carts do not form a stack, but rather quantum stockpile in the same space. This behaviour is useful for [[megaprojects]] and [[trap design]] with minecarts as the weaponry. Moderation should still be exercised: carts take longer to fall into a "stacking" tile already occupied by other carts and will spend that time "hanging" in the air above the stack. This can lead to following carts striking them, which can cause all kinds of malfunctions. The extra time is two game steps for every cart already in the stack, which doesn't hurt stacks of ten carts very much but makes stacks of 100+ rather impractical.

These minecarts on the upper level generally need to be struck with another minecart to move out, or have their support removed. The latter option is safest done by shooting it away with another minecart, manual removal of a stack-supporting cart typically causes the next cart from the stack to [[fun|fall on top]] of the hauler.

=== Perfectly Elastic Collisions ===
Minecart collisions are perfectly elastic, meaning that not only do minecarts not take damage, but that two carts that are rolling which have frontal collisions of near-similar speed, and where one cart is no more than twice the mass of the other cart, will result in a billiard-ball-like effect of the lighter cart bouncing off the heavier cart with a proportional speed increase dependent upon the relative momentum behind the heavier cart.

Using this trick with carts already at the 270,000 maximum speed from ramps can result in "supersonic" carts traveling at speeds in the millions (travelling a dozen tiles per tick), but where they are suddenly subject to 10,000 units of "terminal velocity" friction per tick. [http://www.bay12forums.com/smf/index.php?topic=137557.0 Thread with SCIENCE here].

While hypothetically capable of launching a minecart into orbit when used in conjunction with a ramp, no cargo can be contained in the launched cart, as the collisions will force ejections of the cargo. Your "unwilling volunteer" [[goblin]] space pioneers will simply become paste underneath the wheels of an extreme high-speed cart.

== Non-standard uses ==
Minecarts include some interesting characteristics that have motivated uses beyond hauling. They can be useful for creating fully-automated [[exploit|quantum stockpiles]] and [[garbage disposal]]s. Storing perishable goods (meat, meals, etc.) inside a minecart appears to guard against rot and vermin.
Minecarts can be [[Trap_design#Minecarts|used as weapons]], or as (hopefully non-fatal) triggers to restart stalled [[healthcare]]. They can also be used to time/control game events, either using a basic [[repeater]] or much more advanced [[minecart logic]].
Minecarts trigger [[pressure plate]]s, which means a trap can be designed to trigger when a thief attempts to steal a minecart.
A pressure plate can be used as automatic and more precise custom "launch when full enough" system - as long as weight of your minecarts stays the same. You cannot build a hatch or roller on the same tile, so launch by bumping with another cart. {{cite forum|15096/4580050}}
Dwarves riding minecarts can attack enemies within reach (which goes back to dev log). This applies to shooting, and they actually can hit targets while riding by.{{cite forum|109460/5266119}} Whether a minecart protects the rider and how it interacts with dodging is not known yet. Minecart riders can also [[Swimming#Minecart_training|train swimming]] and [[Megaprojects#Surveillance_Track|detect ambushers]].

== Adventure mode ==
In addition to being used for hauling, minecarts can also be ridden in [[adventure mode]]. (Adapted from forum thread {{cite forum|122903/4258212}})

# If the minecart is in your inventory, drop it. If it is already on the ground, proceed to step 2.
# Press {{k|u}} when you are 1 tile away from the minecart (or standing on the same tile as the minecart).
# You will be presented with the following options:
[[File:minecart adventure mode menu.png|left]]
{{clear}}
* If you {{DFtext|Push}} the minecart, it will move a few tiles in the direction you chose. Physics comes into play here, so it will gain/lose speed depending on the usual factors.
* If you {{DFtext|Ride}} the minecart, you will hop into the minecart, even if you were a tile away, and it will move in the chosen direction with you in it. It will gain/lose speed depending on the usual factors. Whilst the minecart is in motion, you should press {{k|.}} to skip your turn; if you attempt to move whilst the minecart is still in motion, the laws of physics come into play, and you will take [[wound|damage]]. Alternatively, you can push the minecart whilst it's still in motion (although it's unclear how one can bend [[physics]] so as to push a moving minecart whilst inside the minecart). If you push it in the same direction you are already travelling in, you will greatly increase the minecart's velocity. You can also push it in different directions, and this will cause it to gradually change direction-the amount of pushes this requires depends on the minecart's velocity. Once the minecart has stopped moving, you may move out of it safely, or you may want to give it another push. Note that if you push a minecart right after having ridden it (still on the same tile as the minecart), it will act as though you chose to ''ride'' it.

If you want to test this out without creating an adventurer, the [[object testing arena]] allows you to spawn minecarts ({{k|k}}-{{k|c}}-{{k|n}})

== Forging and Melting ==
* Metal minecarts cost '''two''' [[metal]] bars to forge, or '''six''' [[adamantine]] wafers.
* When a non-adamantine metal minecart is melted down, it will return '''1.8''' metal bars, for an '''efficiency of 90%'''.
* When an adamantine minecart is melted down, it will produce '''1.8''' wafers, for an '''efficiency of 30%'''.

== See also ==
* [http://www.bay12forums.com/smf/index.php?topic=109460.0 The "How Does Minecart" Thread] by '''Girlinhat''' et al.
* [http://www.bay12forums.com/smf/index.php?topic=112831.0 SCIENCE: Quantifying minecart physics] by '''Snaake''' et al.
* [http://www.bay12forums.com/smf/index.php?topic=129676.0 How to build a Multi-cart Ore to Magma Minecart Project without needing power] by '''WanderingKid'''.
* [http://www.bay12forums.com/smf/index.php?topic=144328.0 My very own Minecart Education Thread. Ten Lessons, now complete.] by '''Larix'''.

== Bugs ==
*A dwarf will drop her [[child|baby]], if she has one, when boarding a minecart set to be ridden.
*Dwarves have no concept of traffic safety and will walk into busy minecart lines to retrieve objects, often with deadly consequences. This is especially problematic in [[Swimming#Minecart_training|clever applications]] depending on dwarves riding the carts very frequently, because they have a bad habit of dumping their worn clothes on the tracks after a minecart ride. Adding an automatically-operated [[hatch cover]] at the end of such a ride can help prevent [[unfortunate accident]]s.
*Dwarves cannot guide a minecart through an unlocked door unless another dwarf opens the door.{{bug|6056}}
*It is possible for a creature and minecart moving towards each other to pass without collision if they exchange tiles in the same tick.
*After a minecart ride, a dwarf will sometimes haul the minecart to a storage stockpile, leaving another dwarf to haul the vehicle back to the route.
*Minecarts falling onto a floor injure creatures in the tile below the floor.{{bug|6068}}
*A minecart's initial velocity is not affected by weight, when pushed or launched from rollers.{{bug|6296}}
*Removing a stop that has a vehicle waiting on it may cause the game to crash.{{bug|5980}}

{{Category|Fortress mode}}
{{Category|Interface}}

[[ru:Minecart]]

Two-legged rhino lizard

2015-07-04T05:53:36Z

NW Kohaku:

{{Quality|Exceptional|01:29, 10 June 2010 (UTC)}}
{{verminlookup/0|wiki=no}}
{{av}}
{{creaturedesc}}

[[File:Vermin-TwoLeggedRhinoLizard.JPG|thumb|left|Admired for its crawl.]]

'''Two-legged rhino lizards''' are a (fictional) type of [[vermin]] unique to [[savage]] areas. Aside from the savage requirement, however, they are ubiquitous, from scorching desert to glaciers. They are essentially a lizard larger than a crow with only two legs. They are VERMIN_EATER with a PENETRATE_POWER of 2, which means they're better at gnawing their way through your barrels than most vermin.

They are also different from regular lizards in that they are not hateable creatures, and are worth twice as much as pets as normal vermin, as a "reward" for savage embarks.

{{gamedata}}
{{vermin}}

Two-legged rhino lizard

2015-07-04T05:51:37Z

NW Kohaku:

{{Quality|Exceptional|01:29, 10 June 2010 (UTC)}}
{{verminlookup/0|wiki=no}}
{{av}}
{{creaturedesc}}

[[File:Vermin-TwoLeggedRhinoLizard.JPG|thumb|left|Admired for its crawl.]]

'''Two-legged rhino lizards''' are a (fictional) type of [[vermin]] unique to [[savage]] areas. They are essentially a lizard larger than a crow with only two legs. They are VERMIN_EATER with a PENETRATE_POWER of 2, which means they're better at gnawing their way through your barrels than most vermin.

They are also different from regular lizards in that they are not hateable creatures, and are worth twice as much as pets as normal vermin, as a "reward" for savage embarks.

{{gamedata}}
{{vermin}}

Large rat

2015-07-04T00:37:21Z

NW Kohaku:

{{Quality|Exceptional|14:24, 26 July 2010 (UTC)}}
{{Creaturelookup/0
|wiki=no
|contrib=no
|skin=hide
|lung=0-2
|heart=0-1
|intestine=0-1
|liver=0-1
|tripe=0-1
|sweetbread=0-1
|spleen=0-1
|kidney=0-2
|skull=1
|meat=6-13
|fat=6-13
|brain=0-1
|bone=4-12
}}
{{av}}
{{creaturedesc}}

Not to be confused with the even bigger [[giant rat]].

'''Large rats''' are cavern-dwelling rodents that are not very dangerous but surprisingly quick. If one manages to sneak into your fortress, it will attempt to steal your [[food]] and [[alcohol|booze]]. Fresh recruits may have a hard time catching these pests if they have room to run.

While they aren't hard to capture with some bait food surrounded by traps, they have a very short lifespan that forces micromanagement to keep breeding pairs going, and their meager butchery products are not worth the effort when there are much better animals lurking in the caverns.

{{gamedata}}
{{Creatures}}
{{Category|Animals}}

Farm size calculations

2015-06-30T03:10:03Z

NW Kohaku: Corrected math mistake, added advice about slower-growing crops

{{Quality|Fine|21:40, 3 April 2012 (UTC)}}
{{av}}

[[Dwarves]] require approximately 8 units of [[food]] and 15 units of [[drink]] each year. [[Farming]] can produce enough [[crop]]s to satisfy part or all of these requirements. However, be aware that the more and larger your farms are, the more labor time must be accorded to their maintenance.

==The math==
Your dwarves can plant 1 [[seed]] per tile on each [[farm plot]], and depending on the [[skill]] of the [[grower]], whether the farm plot was [[fertilizer|fertilized]], and random chance, each planted tile will yield a stack of anywhere from 0 to 9 crops, depending on farmer skill and fertilization. Legendary farmers can consistently produce either 4 or 5 (average of about 4.7) without fertilizer, while they will produce 8 or 9 with fertilizer.

[[Brewing]] always quintuples stack sizes; for example, a stack of [[cave wheat]] [5] is brewed into a [[barrel]] of [[Dwarven beer]] [25] at a [[still]]. Processing [[quarry bush]] plants into quarry bush leaves at a [[farmer's workshop]] also quintuples stack size, as does processing [[sweet pod]]s into [[Dwarven syrup]]. ([[Mill]]ing does ''not'' increase stack size.) These larger stacks are generally not usable directly as food, but can be [[cook]]ed into prepared meals. [[Cave wheat]], [[sweet pod]]s and [[quarry bush]]es grow 67% slower than other crops, (although, except for cave wheat, are the ones that produce 5 times as much food,) and as long as the mature plants are harvested promptly, it is not hard to grow multiple crops of either plant each season from the same plot.

{| class="wikitable"
! Plant Name
! Active Seasons
! Days Per Harvest
! Harvests Per Tile Per Season
! Harvests Per Tile Per Year
! Average Plants Harvested Per Tile Per Year
! Average Processed Processed Food/Drink Per Tile Per Year
|-
|Plump helmet
|4
|25
|3
|12
|60
|300
|-
|Pig tail
|2
|25
|3
|6
|30
|150
|-
|Cave wheat
|2
|42
|2
|4
|20
|100
|-
|Sweet pod
|2
|42
|2
|4
|20
|100
|-
|Quarry bush
|3
|42
|2
|6
|30
|150
|-
|Prickle berry
|4
|25
|3
|12
|60
|300
|-
|Wild strawberry
|4
|25
|3
|12
|60
|300
|-
|Longland grass
|4
|25
|3
|12
|60
|300
|-
|Rat weed
|4
|25
|3
|12
|60
|300
|-
|Fisher berry
|4
|25
|3
|12
|60
|300
|-
|Rope reed
|4
|25
|3
|12
|60
|300
|-
|Sliver barb
|4
|25
|3
|12
|60
|300
|-
|Sun berry
|4
|25
|3
|12
|60
|300
|-
|Whip vine
|4
|25
|3
|12
|60
|300
|}

All garden [[crop]]s take 25 days to reach maturity, and have identical stats to all other above-ground crops, aside from whether it is brewable, millable, or other features.

This calculation assumes all your planters have Legendary skill, and that there are enough of them to avoid any significant labor shortages at planting times.

The general limitation, then, is not the size of the farm, but the skill of the growers, as well as other [[labor]] issues: The availability of seeds, (including ensuring prompt brewing or threshing to regain seeds from crops,) ensuring no [[labor]] shortage for planting or harvesting, keeping [[stockpiles]] close to the farm for minimal travel time, availability of [[bag]]s and [[barrel]]s for threshing and brewing, and that crops are properly stored (in more barrels) away from [[vermin]].

(For a similar reason, the slower-growing crops are not actually any worse crops in terms of labor. You may need to plant crops in more tiles to achieve the same yield, but the ''labor'' is the same 1 labor per seed planted and 1 labor per harvest, and farm plot tiles are cheap.)

Although fertilization hypothetically doubles yields, in practice, it is almost always better to just have twice as much farm than to have to constantly designate more trees to chop, and spend another dwarf labor to burn the logs into ash and ''another'' to turn ash into potash. Since the size of even a fully-fledged fortress's farmland is generally trivial compared to the overall fortress, the only meaningful measurement of efficiency is amount of time spent in dwarf labor per unit of food. Since fertilization takes more than three times as many labors per tile to produce less than twice as much food, it is never particularly worthwhile to fertilize crops unless you are low on seeds for a given plant, and want to turn one seed into twice as many as you would get normally.

A beginning fortress has 7 dwarves, each of which consumes 8 units of food and 15 drink per dwarf per year, or 56 food and 105 drink for the whole fortress for the year. The starting group can theoretically be supported by a single farm tile, but in practice a larger farm will be necessary since a young fortress is unable to use farm tiles to their fullest potential. (Using brewed plump helmets half the year and processed quarry bushes the other half of the year.)

Taking up a "Plump helmets half the year, quarry bushes the other half" strategy with only legendary farmers, you can hypothetically produce up to 150 dwarven wine and 100 quarry bush leaves per year per tile, which is enough for 10 dwarves per tile. A whole 200-dwarf fortress can be kept fed and drunk on just 20 tiles, or a mere single 4x5 farm plot, which is small enough that a single farmer can easily work all the tiles.

Keep in mind, however, that a single farmer will likely not be able to immediately replant all seeds, (especially on the turning of Spring, and the need to replant all plots at once,) and occasionally goes on break and eats, him/herself, probably leading to getting one less harvest per year than expected on several tiles.

Also, remember dwarves require booze variety to avoid bad [[thought]]s and desire food variety to create good thoughts. Even using less-efficient crops, like eating a (non-brewed) fisher berry is capable of feeding 7.5 dwarves per tile, and keeping 20 dwarves drunk per tile. That amounts to 10 tiles for drink and about 28 for food, or 38 total tiles even without booze-cooking or threshing for a full 200-dwarf fortress. Again, however, your farmers will not always be able to get maximum yields, but even so, about 50 tiles of farmland will provide all the food your fortress will ever need, even if divided between disparate types of less-efficient crops, and that is still within the range of what a single farmer can farm.

Additionally, if your dwarves are going to grow textiles (and [[dye]]s) for [[clothing]] they will need more farmland.

At bare minimum, each dwarf needs 4 types of clothing (torso, head, legs, and feet), taking 4 units of cloth per 3 years to prevent unhappy thoughts. Dye does nothing for happiness and is useless unless making a trade good for [[value]]. This totals up to extremely little cloth necessary to keep a fortress running - 268 cloth per year is only about 4 tiles of dedicated rope reed farm, or 8 tiles of dedicated pig tail farm for even a 200-dwarf fortress. (Just don't brew your cloth.) Additional tiles will probably be necessary for cloth to create more bags and possibly rope.

==Approaches==
Some fortresses begin with a single large farm (5x5) with [[plump helmet]]s. However, if you embark with crops and brew them immediately, it is better to start with a few smaller farms (3x3 or 1x5 are common) with a wider variety of crops. Given the small number of dwarves, only a few tiles (about 10 total) are needed for a beginning fortresses, although you can plow a plot and leave it fallow until you have more dwarfpower to spare your farmer to dedicated farming. As the growers [[experience|level up]], farm yields will increase, lowering the need for large plots. Smaller plots with diverse crops can be used, instead. The more tiles of farm plot you have, the more growers (and harvesters) you will need. A single legendary farmer can seed up to about 100 tiles of farmland if they never harvest themselves and the seed stockpile is only a half-dozen tiles from all farm plot tiles. Consider making the seed stockpile in the middle of a ring of farms to save travel time.

Since a tile is "aboveground" if it has EVER been the top non-open space tile, underground and aboveground farms can be placed side-by-side, and the pit you dug to make the aboveground farm can be [[bridge]]d, [[floor]]ed, or [[wall]]ed over.

If you plan to [[farming|fertilize]], farm plots should ideally be one less than a multiple of 4 tiles -- ex. (1x3), (1x7), (3x5), (3x9), (5x7), (7x9)

{{Template:Farming FAQ}}

Farm size calculations

2015-06-29T22:20:43Z

NW Kohaku: /* The math */

{{Quality|Fine|21:40, 3 April 2012 (UTC)}}
{{av}}

[[Dwarves]] require approximately 8 units of [[food]] and 15 units of [[drink]] each year. [[Farming]] can produce enough [[crop]]s to satisfy part or all of these requirements. However, be aware that the more and larger your farms are, the more labor time must be accorded to their maintenance.

==The math==
Your dwarves can plant 1 [[seed]] per tile on each [[farm plot]], and depending on the [[skill]] of the [[grower]], whether the farm plot was [[fertilizer|fertilized]], and random chance, each planted tile will yield a stack of anywhere from 0 to 9 crops, depending on farmer skill and fertilization. Legendary farmers can consistently produce either 4 or 5 (average of about 4.7) without fertilizer, while they will produce 8 or 9 with fertilizer.

[[Brewing]] always quintuples stack sizes; for example, a stack of [[cave wheat]] [5] is brewed into a [[barrel]] of [[Dwarven beer]] [25] at a [[still]]. Processing [[quarry bush]] plants into quarry bush leaves at a [[farmer's workshop]] also quintuples stack size, as does processing [[sweet pod]]s into [[Dwarven syrup]]. ([[Mill]]ing does ''not'' increase stack size.) These larger stacks are generally not usable directly as food, but can be [[cook]]ed into prepared meals. [[Cave wheat]], [[sweet pod]]s and [[quarry bush]]es grow 40% slower than other crops, (although, except for cave wheat, are the ones that produce 5 times as much food,) and as long as the mature plants are harvested promptly, it is not hard to grow multiple crops of either plant each season from the same plot.

{| class="wikitable"
! Plant Name
! Active Seasons
! Days Per Harvest
! Harvests Per Tile Per Season
! Harvests Per Tile Per Year
! Average Plants Harvested Per Tile Per Year
! Average Processed Processed Food/Drink Per Tile Per Year
|-
|Plump helmet
|4
|25
|3
|12
|60
|300
|-
|Pig tail
|2
|25
|3
|6
|30
|150
|-
|Cave wheat
|2
|42
|2
|4
|20
|100
|-
|Sweet pod
|2
|42
|2
|4
|20
|100
|-
|Quarry bush
|3
|42
|2
|6
|30
|150
|-
|Prickle berry
|4
|25
|3
|12
|60
|300
|-
|Wild strawberry
|4
|25
|3
|12
|60
|300
|-
|Longland grass
|4
|25
|3
|12
|60
|300
|-
|Rat weed
|4
|25
|3
|12
|60
|300
|-
|Fisher berry
|4
|25
|3
|12
|60
|300
|-
|Rope reed
|4
|25
|3
|12
|60
|300
|-
|Sliver barb
|4
|25
|3
|12
|60
|300
|-
|Sun berry
|4
|25
|3
|12
|60
|300
|-
|Whip vine
|4
|25
|3
|12
|60
|300
|}

All garden [[crop]]s take 25 days to reach maturity, and have identical stats to all other above-ground crops, aside from whether it is brewable, millable, or other features.

This calculation assumes all your planters have Legendary skill, and that there are enough of them to avoid any significant labor shortages at planting times.

The general limitation, then, is not the size of the farm, but the skill of the growers, as well as other [[labor]] issues: The availability of seeds, (including ensuring prompt brewing or threshing to regain seeds from crops,) ensuring no [[labor]] shortage for planting or harvesting, keeping [[stockpiles]] close to the farm for minimal travel time, availability of [[bag]]s and [[barrel]]s for threshing and brewing, and that crops are properly stored (in more barrels) away from [[vermin]].

Although fertilization hypothetically doubles yields, in practice, it is almost always better to just have twice as much farm than to have to constantly designate more trees to chop, and spend another dwarf labor to burn the logs into ash and ''another'' to turn ash into potash. Since the size of even a fully-fledged fortress's farmland is generally trivial compared to the overall fortress, the only meaningful measurement of efficiency is amount of time spent in dwarf labor per unit of food. Since fertilization takes more than three times as many labors per tile to produce less than twice as much food, it is never particularly worthwhile to fertilize crops unless you are low on seeds for a given plant, and want to turn one seed into twice as many as you would get normally.

A beginning fortress has 7 dwarves, each of which consumes 8 units of food and 15 drink per dwarf per year, or 56 food and 105 drink for the whole fortress for the year. The starting group can theoretically be supported by a single farm tile, but in practice a larger farm will be necessary since a young fortress is unable to use farm tiles to their fullest potential. (Using brewed plump helmets half the year and processed quarry bushes the other half of the year.)

Taking up a "Plump helmets half the year, quarry bushes the other half" strategy with only legendary farmers, you can hypothetically produce up to 150 dwarven wine and 100 quarry bush leaves per year per tile, which is enough for 10 dwarves per tile. A whole 200-dwarf fortress can be kept fed and drunk on just 20 tiles, or a mere single 4x5 farm plot, which is small enough that a single farmer can easily work all the tiles.

Keep in mind, however, that a single farmer will likely not be able to immediately replant all seeds, (especially on the turning of Spring, and the need to replant all plots at once,) and occasionally goes on break and eats, him/herself, probably leading to getting one less harvest per year than expected on several tiles.

Also, remember dwarves require booze variety to avoid bad [[thought]]s and desire food variety to create good thoughts. Even using less-efficient crops, like eating a (non-brewed) fisher berry is capable of feeding 7.5 dwarves per tile, and keeping 20 dwarves drunk per tile. That amounts to 10 tiles for drink and about 28 for food, or 38 total tiles even without booze-cooking or threshing for a full 200-dwarf fortress. Again, however, your farmers will not always be able to get maximum yields, but even so, about 50 tiles of farmland will provide all the food your fortress will ever need, even if divided between disparate types of less-efficient crops, and that is still within the range of what a single farmer can farm.

Additionally, if your dwarves are going to grow textiles (and [[dye]]s) for [[clothing]] they will need more farmland.

At bare minimum, each dwarf needs 4 types of clothing (torso, head, legs, and feet), taking 4 units of cloth per 3 years to prevent unhappy thoughts. Dye does nothing for happiness and is useless unless making a trade good for [[value]]. This totals up to extremely little cloth necessary to keep a fortress running - 268 cloth per year is only about 4 tiles of dedicated rope reed farm, or 8 tiles of dedicated pig tail farm for even a 200-dwarf fortress. (Just don't brew your cloth.) Additional tiles will probably be necessary for cloth to create more bags and possibly rope.

==Approaches==
Some fortresses begin with a single large farm (5x5) with [[plump helmet]]s. However, if you embark with crops and brew them immediately, it is better to start with a few smaller farms (3x3 or 1x5 are common) with a wider variety of crops. Given the small number of dwarves, only a few tiles (about 10 total) are needed for a beginning fortresses, although you can plow a plot and leave it fallow until you have more dwarfpower to spare your farmer to dedicated farming. As the growers [[experience|level up]], farm yields will increase, lowering the need for large plots. Smaller plots with diverse crops can be used, instead. The more tiles of farm plot you have, the more growers (and harvesters) you will need. A single legendary farmer can seed up to about 100 tiles of farmland if they never harvest themselves and the seed stockpile is only a half-dozen tiles from all farm plot tiles. Consider making the seed stockpile in the middle of a ring of farms to save travel time.

Since a tile is "aboveground" if it has EVER been the top non-open space tile, underground and aboveground farms can be placed side-by-side, and the pit you dug to make the aboveground farm can be [[bridge]]d, [[floor]]ed, or [[wall]]ed over.

If you plan to [[farming|fertilize]], farm plots should ideally be one less than a multiple of 4 tiles -- ex. (1x3), (1x7), (3x5), (3x9), (5x7), (7x9)

{{Template:Farming FAQ}}

Farming

2015-06-29T22:18:15Z

NW Kohaku: /* See also */

{{Quality|Masterwork|23:04, 8 April 2015 (UTC)}}
{{av}}
[[Image:Df-crops-diagram.png|thumb|200px|General farming flowchart.]]

'''Farming''' is the act of growing [[crop|crops]] for [[food]], [[alcohol]] production and [[cloth]] manufacturing. While small forts can easily be sustained by plant gathering, [[hunting]] and trading, farming is vital to large settlements.

Farming is done at a '''farm plot''' building ({{k|b}}-{{k|p}}, resize with {{k|u}}{{k|m}}{{k|k}}{{k|h}}). Building uses no resources, and can only be done on soil or muddied rock. Mud-free stone will not allow the building of a farm plot on top. The "Farming (Fields)" [[labor]] must be enabled. Farm plots only display the kind of crops that they are able to grow when selected with the {{k|q}}uery key.

Depending on where the farm plot is constructed, different crops may be planted. Farm plots built [[above ground]] are not suitable for the crops grown on [[Tile_attributes | subterranean]] farm plots and vice versa. Note that the attributes {{DFtext|Inside|6:0:0}}, {{DFtext|Outside|3:0:1}} are of no relevance. You can grow surface plants indoors by channelling out the roof above the desired plot and then constructing a floor ({{k|b}}-{{k|C}}-{{k|f}}) over the open space. Doing this changes the tile from {{DFtext|Dark|0:0:1}} to {{DFtext|Light|6:0:1}}, despite there being a roof (you do '''not''' need to make the roof out of [[glass]] for this to work).

Note that although you can construct a farm plot anywhere there is either a soil floor or a mud covering, this does not always mean seeds can be planted there. Certain biomes will not allow planting certain seeds, and some biomes will prevent the planting of '''all''' above-ground crops.

The yellow warning message, {{DFtext|No mud/soil for farm, Mud is left by water|6:0:1}}, is displayed on all above-ground tiles, regardless of whether the farm will function.{{version|0.34.11}} This warning may be ignored. Tiles that actually lack mud or soil are excluded from the construction entirely with a red warning message (either {{DFtext|Blocked|4:0:1}} or {{DFtext|Needs soil or mud|4:0:1}}).

See the article on [[crop]]s for details on the conditions needed to grow the available plants.

== Introduction to Farming ==

First, build a farm plot "building" ({{k|b}}-{{k|p}}, resize with {{k|u}}{{k|m}}{{k|k}}{{k|h}}) on [[soil]] or [[irrigation|muddy]] rock. Keep your farms ''small'' -- 2x2 up to 4x4 or so. Farms are surprisingly productive. You can always make more farms later if you run low on plants, and having several small farms lets you diversify your crops. (Each farm plot can only grow one kind of plant per season.)

Once the farm plot has been built, you must select which crops to grow. Press {{k|q}} and move the cursor over the farm. You will see a list of crops you can select to grow in the current season. You can change which season is displayed by pressing {{k|a}},{{k|b}},{{k|c}}, or {{k|d}}. Move the blue selector up and down with {{k|-}} and {{k|+}}, and press {{k|Enter}} to choose a crop to plant during that season (highlighted in white). Crops displayed in red cannot be grown at the moment, either due to a lack of seeds, or a lack of growing days left before the crop goes out of season.

You must have the appropriate [[seed]]s to plant a crop on a plot. To easily see how many of each seed you have, you can go to the Kitchen menu ({{k|z}} {{k|right}} {{k|Enter}}).

Since your dwarves require food, booze and clothing, you should set up a combination of plants that will supply all of these. [[Plump helmet]]s are a good beginning crop for a first cave farm, and [[Strawberry|strawberries]] are a good choice for outdoor fields -- both can be eaten raw, or brewed. [[Pig tail]]s produce cloth, which will become important once your clothing starts to [[wear]]. Check the [[crop]]s page for details on different seeds.

Cooking plants destroys their seeds, so you should disable the cooking of plants in the Kitchen menu. Eating them, brewing them, or processing them through a farmer's workshop, quern or millstone will produce seeds.

Instructing a plot to remain fallow ({{k|z}}) during a particular season will tell dwarves not to plant in that plot during that season. Note that, unlike in real life, crop rotation is not necessary; soil productivity is only affected by fertilizing, and the same crop may be grown indefinitely without a decrease in performance, even without fertilizer.

=== Yield and Fertilization ===
{| class="wikitable" style="float:right"
! Farm Size !! Potash !! Per Square
|-
| 1 || 1 || 1.000
|-
| 2 || 1 || 0.500
|-
| 3 || 1 || 0.333
|-
| 4 || 2 || 0.500
|-
| 5 || 2 || 0.400
|-
| 6 || 2 || 0.333
|-
| 7 || 2 || 0.286
|-
| 8 || 3 || 0.375
|-
| 11 || 3 || 0.272
|-
| 15 || 4 || 0.266
|-
| 19 || 5 || 0.263
|-
| 23 || 6 || 0.260
|-
| 27 || 7 || 0.259
|}
Each farm tile requires a single seed to be planted. Unfertilized farm tiles can produce a stack of 0-6 plants when harvested, depending upon the skill of the planter and random chance. Experimentally, fertilizing a farm plot boosts production by 1-3 additional plants per stack each harvest, though the exact mechanism is unknown. For unskilled planters, yield can be effectively doubled with the use of fertilizer. This can be particularly important early on, when your fortress's seed supply is limited, because those extra plants mean more seeds for planting next season. Many crops, like quarry bushes, are impossible to farm effectively in the beginning without fertilizer.

To fertilize a farm plot, one needs [[potash]], which is produced by processing [[ash]]. Each plot must be re-fertilized each season, and the fertilizer must be in place at the time the seeds reach maturity. It does not matter whether the plot is fertilized at the time of planting. {{cite forum|139382/5375231}}

Fertilizing a farm plot requires ''floor(plot_size / 4) + 1'' potash. The table on the right illustrates the efficiency of potash as a function of plot size. Generally, larger farms use less, approaching a limit of 1/4 bar per square. The worst yields per tile are multiples of 4; if one plants to optimize harvest yield, it's most efficient to have plots of size ''4n - 1'', where n is the number of potash used. Suitable sizes are 1x3, 1x7, 3x5, 3x9, 5x7, and 7x9. If one plans to optimize farmer experience, plots of size 2 or 4 can fertilized and seeded quickest, and experience can be distributed among more farmers. This ensures that if a bounty of crop is needed in the future, your farmers can yield more without potash, can plant and harvest quicker, and will have more time for other jobs in between.

Fertilizer may be applied to a plot by pressing {{k|f}} while viewing the plot. Only dwarves with the Farming (Fields) labor will apply fertilizer; this grants 30 XP of farming experience for each unit of potash used. Pressing {{k|s}} toggles seasonal fertilization. This does nothing until the next [[season]], at which time the plot will be automatically fertilized. Note that if you do not have a potash stockpile near your farm plots, your legendary farmers may spend all of their time hauling single bars of potash from all the way on the other side of your fortress, rather than growing food.

'''Potash Production Chain:'''
Wood [[Stockpile]] > Wood [[Furnace]] produces [[Ash]] (as [[bars]]) > [[Ashery]] produces [[potash]] (as [[bars]]).
Note: 5 bars are stored in a [[bin]]. An [[Ashery]] requires a [[block]], barrel, and bucket as components.

=== Subterranean Farming ===

To grow the six "dwarven" plants, you will need an underground farm plot. The seeds and spawn available to your dwarves at embark will only grow underground. Underground farm plots must be placed on soil or [[mud]]dy stone.

Muddying a stone floor requires temporarily covering it with water; common methods include a [[Irrigation#via_Buckets|bucket brigade]] or '''controlled''' [[flood]]ing (see: [[Irrigation]]) by temporarily diverting a river or pool, using a [[floodgate]] or [[door]] to stop the flow. You may also find a muddied area in a [[cavern]], but note that each tile underneath the farm plot must be muddied. Most caverns have entire open areas which will be permanently covered in mud, but if you dig into the walls of a cavern or chisel away a pillar, the freshly cut floor area will not be muddied until you get it wet. Underground caverns are dirty, and frequently contain [[Mud|piles of mud]] that are perfect for quickly setting up farms. However, given the wide variety of creatures found in caverns, you may want to take precautions. Consider keeping a [[squad]] close at hand to guard the farm, or walling off a muddied area for your dwarves' exclusive use.

Underground farming is not restricted to soil layers and caverns; underground floor of any material -- rough stone, smoothed stone, ore, gem -- can support subterranean farm plots once there is a layer of mud covering it. See [[irrigation]] for tips on getting the right amount of water to the farm plots.

=== Above Ground Farming ===
Farming of above ground crops is only possible on tiles that lie in a biome supporting their growth. Those are "land" biomes excluding the notoriously cold [[Glacier]] and [[Tundra]], but also all [[Mountain]] [[biome]]s. [[Ocean]] biomes are also excluded, since they are not "land". The biomes where above ground farming is possible are internally referred to as NOT_FREEZING, but that label is somewhat misleading, since it's a [[Biome token|shorthand]] for a group of specific biomes and doesn't imply anything about the actual temperature - mountains and oceans are generally infertile, no matter what temperature range the embark screen lists, and a [[Taiga]] with "freezing" temperatures allows farming above ground plants.

Above ground farming is basically the same as underground farming, with the simplifying distinction that above ground plots typically do not require preparatory work. However, there are some complications.

The first complication is that seeds cannot be chosen at embark, as dwarven civilizations do not have access to those sort of plants. They can be bought from [[Elves|elven]] and [[human]] caravans; above-ground plants can be gathered using the [[Plant gathering]] designation, and then [[brewer|brewed]], [[miller|milled]], [[thresher|threshed]] or [[food|eaten]] directly (depending on the plant) to produce seeds.

The second complication is that the farming must be done on [[soil]] or muddied rock, which is [[above ground]]. Typically, it is done on the surface, which is dangerous (due to aggressive animals, ambushes and sieges). However, any land which has ever been exposed to sunlight becomes permanently marked as "above ground". So, if you have multiple Z-layers of soil, you can channel some above-ground land, remove the resulting ramps, then construct a floor above, where the surface once was. The (now inside and protected) lower soil will still be suitable for farming outdoor plants like [[strawberry|strawberries]], [[longland grass]], [[rope reed]], and anything else you may find. If your soil is not thick enough, you may still get a secure above ground farm by doing the same with any stone and muddying it. Alternatively, you may build a greenhouse by [[wall]]ing around some soil.

Some crops require a particular environment to grow. On an embark which crosses multiple biomes, it's not unusual for aboveground farms in different biomes to have different lists of available crops. Whether this varies only with temperature or also with other climate factors is not yet known.

Note that when creating an above ground plot, the interface may incorrectly display "No mud/soil for farm", even though mud is present. {{bug|249}} The message can be ignored.

== Farm plots in action ==

Once a farm plot has been built and crops have been selected for the current season, dwarves with the [[growing]] labor enabled will begin planting the selected seeds. One seed is used per tile. The higher a Dwarf's grower skill in planting, the more plants will be harvested from each seed planted. The farming labor is fairly low in priority, so if you want a full-time farmer, it is best to disable all other labors.

Plants take time to grow, depending on their type. Once a plant is fully grown, a dwarf will harvest it. By default, any dwarf will do this. Harvesting plants is not affected by any skill, although it provides a small amount of grower experience. So it's a good idea to set only your planters to harvest, not anyone. To do that, set option "Only Farmers Harvest" {{k|o}}{{k|h}}. This is useful only to train your planter faster; once they're skilled enough, everyone can be allowed to harvest again so the haulers can take care of half the farming work.

<div style="float:right">
{| style="border-spacing: 0"
|{{RT|≈|6:0}}||{{RT|`|0:1}}||{{RT|τ|6:1}}||{{RT|═|6:0}}||{{RT|≈|6:0}}
|-
|{{RT|≈|6:0}}||{{RT|≈|6:0}}||{{RT|τ|6:1}}||{{RT|═|6:0}}||{{RT|≈|6:0}}
|-
|{{RT|≈|6:0}}||{{RT|≈|6:0}}||{{RT|τ|6:1}}||{{RT|═|6:0}}||{{RT|≈|6:0}}
|-
|{{RT|≈|6:0}}||{{RT|τ|6:1}}||{{RT|═|6:0}}||{{RT|≈|6:0}}||{{RT|≈|6:0}}
|-
|{{RT|≈|6:0}}||{{RT|τ|6:1}}||{{RT|═|6:0}}||{{RT|≈|6:0}}||{{RT|≈|6:0}}
|}
</div>
In the farm plot shown on the right, {{Tile|≈|6:0}} indicates tiles awaiting planting, {{Tile|═|6:0}} indicates tiles that have been planted and are now growing, and {{Tile|τ|6:1}} indicates [[longland grass]] plants that are ready for harvesting.

If harvested plants are not moved to a stockpile in time, they will wither. These plants will eventually [[rot]] away. There's no use for withered plants. If, when the seasons change, the previous crop can not grow anymore, all immature plants will be destroyed yielding neither seed nor plant. If the farmers are "aware" of this limitation, they will automatically stop planting crops that haven't enough time to ripen, but you might lose a few seeds in your first year when growers of insufficient skill plant seeds too close to the cutoff.

Depending on the number of growers and their experience and the rate at which the plant grows, not all squares of large plots may be used.

Any farm plot that has both Above Ground and Subterranean tile attributes within the plot will only be partially planted, if at all. Verify using {{k|k}} over each square of the plot and remake as needed to follow the proper attributes.

== Management ==

Create a custom [[stockpile]] near your [[farm]] which only accepts [[seed]]s. This will consolidate your seeds into one place, instead of having them littered all through the [[dining room]]. As a single barrel can hold up to 10 seed [[bag]]s (each of which can hold 100 seeds of a specific type), and there is a maximum of 200 seeds of each type in the whole fortress, this stockpile need only be three or four tiles. (For DF2014 the theoretical maximum is 31 tiles for 200 seeds of each of 155 crops, but the actual maximum needed is much less because no fort will be situated in the right place to grow all of those. Four tiles gives enough space for 20 different crops.) Unfortunately, due to an outstanding bug, consolidating your seeds will increase the amount of planting job cancellation spam; see the [[#Bugs|Bugs]] section below for workarounds.

It may also be a good idea to set aside a few seeds from each type of crop and [[forbid]] them, as a seed bank in case of [[fun|fun times]].

You can also create a custom stockpile that will only accept [[plant]]s, to avoid having it all mixed up with your [[meat]] and [[drink]]s. It would be a good idea to have this stockpile near your [[still]], [[farmer's workshop]], [[kitchen]], etc. If you suffer from plump helmet overflow, create a plump-helmet-only stockpile, forbid plump helmets from all other food stockpiles, and let the crops in the field die if they can't be picked. It is worth noting that withering crops in the field do not produce miasma.

Use the [[stocks]] menu, and go to the Kitchen tab. From here you can see how many of each kind of food you have. If you're running out of a certain kind of seed, toggle the corresponding plant "Cook" setting to red. [[Cooking]] plants doesn't leave a seed. If you have too many of a certain kind of seed, or of plump helmet, as noted above, toggle the seed "Cook" setting to blue. Just make sure you check on the stocks and toggle it back before you run out, or use the seed bank idea above.

===Managing Seeds===
[[Seed]]s are used to grow [[crop]]s. You may begin the game with a certain number of seeds, [[trade]] for them, or [[plant gathering|gather]] them. In addition to this, eating, [[milling]] and [[brewing]] plants often yield a seed (assuming your fortress hasn't hit the seed cap for that plant). [[Cooking]] plants does not yield seeds, and cooking seeds makes them unusable for planting, so you may want to watch out and make sure you don't convert the last of your plants into +strawberry roast+ without the ability to make more.

You can create a custom [[stockpile]] near your [[farm]] which will only accept [[seed]]s. This will consolidate your seeds into one place, instead of having them littered all through the [[dining room]]. Seeds are stored in [[bag]]s (up to 100 seeds per bag), and seed bags can be stored in barrels. It is recommended not to use barrels on seeds stockpiles, however, since the hauling habits of the current version lead to barrels getting carted around to collect each and every loose seed, interrupting the planting work.

Each plant has a seed cap set at 200 (this value can be adjusted in [[d_init.txt]]). [[Brewing]], [[milling]], and [[food|eating]] raw plants will not generate additional seeds once the cap is reached, although you may still get additional seed bags via [[trading]] and thus exceed this limit. Once the count of seeds falls below 200, new seeds will again be generated.

There is also a fortress-wide total seed cap, initially set at 3000 (also configurable in [[d_init.txt]]). Once your fortress reaches this cap new seeds will still be generated, but the oldest seeds on the map will disappear. Unfortunately, this cap counts all seeds on the map, including those carried by traders {{bug|8108}}, and removes old seeds even if they have already been planted {{bug|8107}}. Finally, because the two caps behave differently, they can cause undesirable behavior when both are in operation {{bug|8091}}.

Seeds may be toggled for [[cooking]] on the Kitchen tab of the [[stocks]] menu. Disabling seed cooking will keep your seeds safe from starving dwarves. Although the item properties label them as EDIBLE_RAW, [[quarry bush|rock nuts]], like all other seeds, are ''not'' consumed as-is.

===Managing Crops===
When your [[crop]]s are ripe, your dwarves will harvest them from the farm plots. This will yield one or more [[stack]]s of [[plant]]s, which will be [[hauling|hauled]] to the appropriate [[stockpile]]. It is generally a good idea to have sufficient [[barrel]]s to hold the food, as [[food]] is subject to [[wear|withering]] and the predation of [[vermin]]. [[Metal]] barrels are especially effective against vermin.

You can create a custom stockpile that will only accept [[plant]]s, to avoid having it all mixed up with your [[meat]] and [[drink]]s. It would be a good idea to have this stockpile near your [[still]], [[farmer's workshop]], [[kitchen]], etc. You may also choose to make more specialized stockpiles, for instance if your [[windmill]] is located far away from your farms, you might have small nearby stockpiles dedicated solely to millable plants and [[flour]] so as to save on hauling.

The Kitchen tab on the [[stocks]] menu allows you to control which crops, if any, your dwarves will use as ingredients when cooking. Be careful when you are cultivating new crops or running low on others, and make sure you don't cook the last of them instead of recovering the valuable seeds. Note that experienced [[farmer]]s and crop [[fertilize|fertilization]] significantly increase the return on planted seeds, and can be quite useful when attempting to build your seed stockpile.

==Bugs==

* Haulers will frequently take a full, heavy seed barrel from a stockpile to go pick up a single seed bag, having the unfortunate side effect of making all of the hauled seeds unusable for planting and spamming job cancellations. {{bug|5964}}
** Workaround #1: set your seed stockpile to only take from links ({{k|a}}). When seed supplies run low, toggle it back to "anywhere" temporarily to gather up all the loose seeds.
** Workaround #2: disable barrels ({{k|E}}) in the seed stockpile. This means making the stockpile larger, as only one seed bag will be stored per tile. However, at 100 seeds per bag and with the 200 seed cap per seed type (cf. [[seed]]), this still only amounts to 12 tiles for a full underground-crop seed stockpile, assuming each seed type is only stored in 2 bags. Haulers will still take a whole bag to gather individual seeds, but this is better than taking a whole barrel full of seed bags.
** Workaround #3: create two custom [[stockpile]]s which only accept [[seed]]s. Disable barrels in the first stockpile, and set it to give to the second stockpile. Set the second to only take from links.
** Workaround #4: disable seeds in all stockpiles and recruit a few extra farmers. No hauled seeds means no planting job cancellation spam.

* Fortress-wide seed cap counts seeds carried by traders {{bug|8108}}
* Fortress-wide seed cap removes seeds that have already been planted {{bug|8107}}
* Conflict between seed caps can cause all seeds for a crop to disappear {{bug|8091}}

{{Farming FAQ}}

== See also ==
* [[Irrigation]]
* [[Tile attributes]]
* [[Crops]]
* [[How large a farm do i need|How large a farm do I need?]]

{{Category|Buildings}}
{{Industry}}

Food

2015-06-29T22:17:47Z

NW Kohaku: /* See Also */

{{Quality|Superior|01:05, 4 February 2015 (UTC)}}
{{av}}

Dwarves may be [[alcohol]]ics, but they cannot live on drink alone; they also need '''food'''. Hungry dwarves are indicated by a flashing brown arrow. Unfed dwarves will progress from hunger to starvation and, ultimately, to death.

== Mechanics of Eating and Hunger ==
Dwarves require about 2 units of food each season. Dwarves that go without food will do the obvious: become increasingly hungry, work more slowly, become more and more unhappy, and eventually [[death|die]] of starvation. Hungry dwarves that cannot get at fortress resources will steal food from any [[caravan]]s that arrive; the merchants do not particularly care, but it is added to their expenses when the caravan leaves the map. Additionally, when starving, dwarves will catch and consume [[vermin]] to survive, resulting in an unhappy thought.

Dwarves will forgo food, drink, and [[sleep]] for a while to complete tasks they are currently performing; how long they will go on depends on their [[personality]], but dwarves will generally not endanger their lives to finish a job. Dwarves without a current job will perform these activities if they are even a little thirsty, hungry, or drowsy, and will only snap to "No job" once they have done so. The only task that can actually lead to death by preventing a dwarf from covering their vital necessities is a mother trying to find her [[children|infant]]{{verify}}.

Dwarves who don't get enough exercise will quickly become fat, a change that can only be seen by examining their [[thoughts and preferences]] screen. Not surprisingly, fat dwarves are slower at moving around, but the extra fat provides additional insulation from extreme temperatures, a small amount of additional protection against attacks, and longer "burn time" when exposed to [[fire]]. A dwarf's fat stores are depleting by the mere fact of existing, but this happens very slowly. As a dwarf becomes hungrier, they use up more fat, and will die when their reserves are completely exhausted. Fat dwarves can be made fit by giving them more physical and less intellectual things to do; a [[hauling]] regimen works wonders, for instance, and leaves the player wondering why it's so hard for people to shed weight in real life, when all they have to do is move [[stone]] from place to place.

Thirst, Hunger, and Drowsiness each increment by 1 during each game tick (e.g. 1200 per day, 33600 per month, 403200 per year), possibly more if the dwarf is a mother carrying her child. When they reach certain thresholds, the following things happen.

Thirst:
* 20000 - dwarf starts considering getting something to drink (1/120 chance per tick) if idle
* 22000 - dwarf decides to go get something to drink if idle
* 25000 - dwarf starts flashing "Thirsty"
* 35000 - dwarf gets an unhappy thought about being Thirsty and cancels its current job to get something to drink
* 50000 - dwarf starts flashing "Dehydrated"
* 60000 - dwarf gets an unhappy thought about being Dehydrated
* 75000 - dwarf dies of thirst

Hunger:
* 40000 - dwarf starts considering getting something to eat (1/120 chance per tick) if idle
* 45000 - dwarf decides to go get something to eat if idle
* 50000 - dwarf starts flashing "Hungry"
* 65000 - dwarf gets an unhappy thought about being Hungry and cancels its current job to get something to eat
* 75000 - dwarf starts flashing "Starving" and begins hunting for vermin
* 85000 - dwarf gets an unhappy thought about being Starving
* 100000 - dwarf starves to death (unless it still has stored fat, at which point it starts burning through it rapidly)

Drowsiness:
* 50000 - dwarf starts considering going to bed (1/120 chance per tick) if idle
* 54000 - dwarf decides to go to bed if idle
* 57600 - dwarf starts flashing "Drowsy"
* 65000 - dwarf get an unhappy thought about being Tired
* 150000 - dwarf starts flashing "Very Drowsy"
* 160000 - dwarf get an unhappy thought about being Exhausted
* 200000 - dwarf goes insane

Completing an Eat/Drink job decreases the relevant counter by 50000 (to a minimum of zero), though they may also decrement it additional times during the job's progress.

Prior to version 0.31.07 (and going all the way back to the 2D versions), the unhappy Thoughts resulting from hunger/thirst/drowsiness occurred at the exact same time that the dwarf started flashing, but all of the other numbers were otherwise the same. Additionally, in earlier versions (most notably 40d and earlier) dwarves cancelled jobs for food/drink/sleep much more readily.

== Thoughts ==
There are a number of good and bad [[thoughts]] associated with food. Food cooked from or consisting of ingredients the dwarf [[preferences|likes]] will generate a happy thought. High quality food will improve this happy thought, making a good [[cook]] a valuable addition to the fort.

Dining in a high-quality setting will also bring a happy thought, making a legendary [[dining room]] an easy way to bring up happiness.

On the other hand, eating the same food over and over again will make the dwarf tire of it, and they will crave new dining. Having a particularly limited dining selection will cause this thought to manifest, more likely early in a fortress's life. For this reason, it is important to get your food industry running, to provide more of a selection to the dwarves. Additional food of most categories can also be purchased from a [[caravan]].

== Food groups ==
Food can be divided into several food groups; the state of the fortress's food reserves can be seen on the [[status]] screen, with the 2 important groups being 'drink' and 'other' (includes prepared meals). Any sort of accurate count will require a [[bookkeeper]]. The same goes for the {{k|z}}-stocks screen that gives a fully detailed overview.

*[[Plant]]s can be [[farming|farmed]] or [[plant gathering|gathered]], and are also the only food group besides [[honey]] that can be processed into drink. Farms are reliable and (usually) easily extendable sources of food, and generally form the backbone of most fortresses' food production.
*[[Meat]] can be sourced from [[meat industry|livestock]], [[hunting|hunted]], [[cage trap|caught live]] and then killed for [[arena|military training]], or stripped from siege [[mount]]s. Meat is more difficult to procure, but comes with important secondary resources ([[leather]], [[fat]], [[bones]]) and provides more variety than plants at a significantly easier rate.
*[[Fish]] can be caught, either via [[fishing]] or [[drowning chamber|fishing chambers]]. This is the most dependent of the industries, requiring a body of water (be it an [[ocean]], a [[lake]], or a [[river]]). Larger fish caught via fish traps are slaughtered, and their parts counted as part of the meat industry.
*[[Egg]]s can be sourced from a [[egg production|hatchery]]. Any [[tame]] [[Egg_production#Egg-laying_Animals|egg-laying]] female animal will do so occasionally when allowed access to an unclaimed [[nest box]], including very exotic animals like [[alligator]]s and [[roc]]s. These eggs can then be cooked.
*[[Milk]] can be [[milking|milked]] from certain tame female animals, including more exotic ones like [[kangaroo]]s and [[tapir]]s. Milk can be cooked or processed into higher-value [[cheese]].
*[[Honey]] and [[royal jelly]] can be produced via [[beekeeping]], and can be cooked or processed into [[mead]].

Note that most food is subject to [[Miasma#Food_rot|rotting]] if not stored properly.

==See Also==
*[[How large a farm do i need|How large a farm do I need?]]
*[[Egg production]]
*[[Meat industry]]

{{Category|Food|*}}
{{Industry}}

Food

2015-06-29T22:17:34Z

NW Kohaku:

{{Quality|Superior|01:05, 4 February 2015 (UTC)}}
{{av}}

Dwarves may be [[alcohol]]ics, but they cannot live on drink alone; they also need '''food'''. Hungry dwarves are indicated by a flashing brown arrow. Unfed dwarves will progress from hunger to starvation and, ultimately, to death.

== Mechanics of Eating and Hunger ==
Dwarves require about 2 units of food each season. Dwarves that go without food will do the obvious: become increasingly hungry, work more slowly, become more and more unhappy, and eventually [[death|die]] of starvation. Hungry dwarves that cannot get at fortress resources will steal food from any [[caravan]]s that arrive; the merchants do not particularly care, but it is added to their expenses when the caravan leaves the map. Additionally, when starving, dwarves will catch and consume [[vermin]] to survive, resulting in an unhappy thought.

Dwarves will forgo food, drink, and [[sleep]] for a while to complete tasks they are currently performing; how long they will go on depends on their [[personality]], but dwarves will generally not endanger their lives to finish a job. Dwarves without a current job will perform these activities if they are even a little thirsty, hungry, or drowsy, and will only snap to "No job" once they have done so. The only task that can actually lead to death by preventing a dwarf from covering their vital necessities is a mother trying to find her [[children|infant]]{{verify}}.

Dwarves who don't get enough exercise will quickly become fat, a change that can only be seen by examining their [[thoughts and preferences]] screen. Not surprisingly, fat dwarves are slower at moving around, but the extra fat provides additional insulation from extreme temperatures, a small amount of additional protection against attacks, and longer "burn time" when exposed to [[fire]]. A dwarf's fat stores are depleting by the mere fact of existing, but this happens very slowly. As a dwarf becomes hungrier, they use up more fat, and will die when their reserves are completely exhausted. Fat dwarves can be made fit by giving them more physical and less intellectual things to do; a [[hauling]] regimen works wonders, for instance, and leaves the player wondering why it's so hard for people to shed weight in real life, when all they have to do is move [[stone]] from place to place.

Thirst, Hunger, and Drowsiness each increment by 1 during each game tick (e.g. 1200 per day, 33600 per month, 403200 per year), possibly more if the dwarf is a mother carrying her child. When they reach certain thresholds, the following things happen.

Thirst:
* 20000 - dwarf starts considering getting something to drink (1/120 chance per tick) if idle
* 22000 - dwarf decides to go get something to drink if idle
* 25000 - dwarf starts flashing "Thirsty"
* 35000 - dwarf gets an unhappy thought about being Thirsty and cancels its current job to get something to drink
* 50000 - dwarf starts flashing "Dehydrated"
* 60000 - dwarf gets an unhappy thought about being Dehydrated
* 75000 - dwarf dies of thirst

Hunger:
* 40000 - dwarf starts considering getting something to eat (1/120 chance per tick) if idle
* 45000 - dwarf decides to go get something to eat if idle
* 50000 - dwarf starts flashing "Hungry"
* 65000 - dwarf gets an unhappy thought about being Hungry and cancels its current job to get something to eat
* 75000 - dwarf starts flashing "Starving" and begins hunting for vermin
* 85000 - dwarf gets an unhappy thought about being Starving
* 100000 - dwarf starves to death (unless it still has stored fat, at which point it starts burning through it rapidly)

Drowsiness:
* 50000 - dwarf starts considering going to bed (1/120 chance per tick) if idle
* 54000 - dwarf decides to go to bed if idle
* 57600 - dwarf starts flashing "Drowsy"
* 65000 - dwarf get an unhappy thought about being Tired
* 150000 - dwarf starts flashing "Very Drowsy"
* 160000 - dwarf get an unhappy thought about being Exhausted
* 200000 - dwarf goes insane

Completing an Eat/Drink job decreases the relevant counter by 50000 (to a minimum of zero), though they may also decrement it additional times during the job's progress.

Prior to version 0.31.07 (and going all the way back to the 2D versions), the unhappy Thoughts resulting from hunger/thirst/drowsiness occurred at the exact same time that the dwarf started flashing, but all of the other numbers were otherwise the same. Additionally, in earlier versions (most notably 40d and earlier) dwarves cancelled jobs for food/drink/sleep much more readily.

== Thoughts ==
There are a number of good and bad [[thoughts]] associated with food. Food cooked from or consisting of ingredients the dwarf [[preferences|likes]] will generate a happy thought. High quality food will improve this happy thought, making a good [[cook]] a valuable addition to the fort.

Dining in a high-quality setting will also bring a happy thought, making a legendary [[dining room]] an easy way to bring up happiness.

On the other hand, eating the same food over and over again will make the dwarf tire of it, and they will crave new dining. Having a particularly limited dining selection will cause this thought to manifest, more likely early in a fortress's life. For this reason, it is important to get your food industry running, to provide more of a selection to the dwarves. Additional food of most categories can also be purchased from a [[caravan]].

== Food groups ==
Food can be divided into several food groups; the state of the fortress's food reserves can be seen on the [[status]] screen, with the 2 important groups being 'drink' and 'other' (includes prepared meals). Any sort of accurate count will require a [[bookkeeper]]. The same goes for the {{k|z}}-stocks screen that gives a fully detailed overview.

*[[Plant]]s can be [[farming|farmed]] or [[plant gathering|gathered]], and are also the only food group besides [[honey]] that can be processed into drink. Farms are reliable and (usually) easily extendable sources of food, and generally form the backbone of most fortresses' food production.
*[[Meat]] can be sourced from [[meat industry|livestock]], [[hunting|hunted]], [[cage trap|caught live]] and then killed for [[arena|military training]], or stripped from siege [[mount]]s. Meat is more difficult to procure, but comes with important secondary resources ([[leather]], [[fat]], [[bones]]) and provides more variety than plants at a significantly easier rate.
*[[Fish]] can be caught, either via [[fishing]] or [[drowning chamber|fishing chambers]]. This is the most dependent of the industries, requiring a body of water (be it an [[ocean]], a [[lake]], or a [[river]]). Larger fish caught via fish traps are slaughtered, and their parts counted as part of the meat industry.
*[[Egg]]s can be sourced from a [[egg production|hatchery]]. Any [[tame]] [[Egg_production#Egg-laying_Animals|egg-laying]] female animal will do so occasionally when allowed access to an unclaimed [[nest box]], including very exotic animals like [[alligator]]s and [[roc]]s. These eggs can then be cooked.
*[[Milk]] can be [[milking|milked]] from certain tame female animals, including more exotic ones like [[kangaroo]]s and [[tapir]]s. Milk can be cooked or processed into higher-value [[cheese]].
*[[Honey]] and [[royal jelly]] can be produced via [[beekeeping]], and can be cooked or processed into [[mead]].

Note that most food is subject to [[Miasma#Food_rot|rotting]] if not stored properly.

==See Also==
*[[Egg production]]
*[[Meat industry]]
*[[How large a farm do i need|How large a farm do I need?]]

{{Category|Food|*}}
{{Industry}}

Farm size calculations

2015-06-29T22:12:38Z

NW Kohaku: You can not longer booze-cook whole roasts since a couple major versions ago. Previous math was wrong.

{{Quality|Fine|21:40, 3 April 2012 (UTC)}}
{{av}}

[[Dwarves]] require approximately 8 units of [[food]] and 15 units of [[drink]] each year. [[Farming]] can produce enough [[crop]]s to satisfy part or all of these requirements. However, be aware that the more and larger your farms are, the more labor time must be accorded to their maintenance.

==The math==
Your dwarves can plant 1 [[seed]] per tile on each [[farm plot]], and depending on the [[skill]] of the [[grower]], whether the farm plot was [[fertilizer|fertilized]], and random chance, each planted tile will yield a stack of anywhere from 0 to 9 crops, depending on farmer skill and fertilization. Legendary farmers can consistently produce either 4 or 5 (average of about 4.7) without fertilizer, while they will produce 8 or 9 with fertilizer.

[[Brewing]] always quintuples stack sizes; for example, a stack of [[cave wheat]] [5] is brewed into a [[barrel]] of [[Dwarven beer]] [25] at a [[still]]. Processing [[quarry bush]] plants into quarry bush leaves at a [[farmer's workshop]] also quintuples stack size, as does processing [[sweet pod]]s into [[Dwarven syrup]]. ([[Mill]]ing does ''not'' increase stack size.) These larger stacks are generally not usable directly as food, but can be [[cook]]ed into prepared meals. [[Cave wheat]], [[sweet pod]]s and [[quarry bush]]es grow 40% slower than other crops, (although, except for cave wheat, are the ones that produce 5 times as much food,) and as long as the mature plants are harvested promptly, it is not hard to grow multiple crops of either plant each season from the same plot.

{| class="wikitable"
! Plant Name
! Active Seasons
! Days Per Harvest
! Harvests Per Tile Per Season
! Harvests Per Tile Per Year
! Average Plants Harvested Per Tile Per Year
! Average Processed Processed Food/Drink Per Tile Per Year
|-
|Plump helmet
|4
|25
|3
|12
|60
|300
|-
|Pig tail
|2
|25
|3
|6
|30
|150
|-
|Cave wheat
|2
|42
|2
|4
|20
|100
|-
|Sweet pod
|2
|42
|2
|4
|20
|100
|-
|Quarry bush
|3
|42
|2
|6
|30
|150
|-
|Prickle berry
|4
|25
|3
|12
|60
|300
|-
|Wild strawberry
|4
|25
|3
|12
|60
|300
|-
|Longland grass
|4
|25
|3
|12
|60
|300
|-
|Rat weed
|4
|25
|3
|12
|60
|300
|-
|Fisher berry
|4
|25
|3
|12
|60
|300
|-
|Rope reed
|4
|25
|3
|12
|60
|300
|-
|Sliver barb
|4
|25
|3
|12
|60
|300
|-
|Sun berry
|4
|25
|3
|12
|60
|300
|-
|Whip vine
|4
|25
|3
|12
|60
|300
|}

All garden [[crop]]s take 25 days to reach maturity, and have identical stats to all other above-ground crops, aside from whether it is brewable, millable, or other features.

This calculation assumes all your planters have Legendary skill, and that there are enough of them to avoid any significant labor shortages at planting times.

The general limitation, then, is not the size of the farm, but the skill of the growers, as well as other [[labor]] issues: The availability of seeds, (including ensuring prompt brewing or threshing to regain seeds from crops,) ensuring no [[labor]] shortage for planting or harvesting, keeping [[stockpiles]] close to the farm for minimal travel time, availability of [[bag]]s and [[barrel]]s for threshing and brewing, and that crops are properly stored (in more barrels) away from [[vermin]].

Although fertilization hypothetically doubles yields, in practice, it is almost always better to just have twice as much farm than to have to constantly designate more trees to chop, and send another dwarf to burn the logs into potash. Since the size of even a fully-fledged fortress's farmland is generally trivial compared to the overall fortress, the only meaningful measurement of efficiency is amount of time spent in dwarf labor per unit of food. Since fertilization takes more than twice as many labors per tile to produce less than twice as much food, it is never particularly worthwhile to fertilize crops unless you are low on seeds for a given plant, and want to turn one seed into twice as many as you would get normally.

A beginning fortress has 7 dwarves, each of which consumes 8 units of food and 15 drink per dwarf per year, or 56 food and 105 drink for the whole fortress for the year. The starting group can theoretically be supported by a single farm tile, but in practice a larger farm will be necessary since a young fortress is unable to use farm tiles to their fullest potential. (Using brewed plump helmets half the year and processed quarry bushes the other half of the year.)

Taking up a "Plump helmets half the year, quarry bushes the other half" strategy with only legendary farmers, you can hypothetically produce up to 150 dwarven wine and 100 quarry bush leaves per year per tile, which is enough for 10 dwarves per tile. A whole 200-dwarf fortress can be kept fed and drunk on just 20 tiles, or a mere single 4x5 farm plot, which is small enough that a single farmer can easily work all the tiles.

Keep in mind, however, that a single farmer will likely not be able to immediately replant all seeds, (especially on the turning of Spring, and the need to replant all plots at once,) and occasionally goes on break and eats, him/herself, probably leading to getting one less harvest per year than expected on several tiles.

Also, remember dwarves require booze variety to avoid bad [[thought]]s and desire food variety to create good thoughts. Even using less-efficient crops, like eating a (non-brewed) fisher berry is capable of feeding 7.5 dwarves per tile, and keeping 20 dwarves drunk per tile. That amounts to 10 tiles for drink and about 28 for food, or 38 total tiles even without booze-cooking or threshing for a full 200-dwarf fortress. Again, however, your farmers will not always be able to get maximum yields, but even so, about 50 tiles of farmland will provide all the food your fortress will ever need, even if divided between disparate types of less-efficient crops, and that is still within the range of what a single farmer can farm.

Additionally, if your dwarves are going to grow textiles (and [[dye]]s) for [[clothing]] they will need more farmland.

At bare minimum, each dwarf needs 4 types of clothing (torso, head, legs, and feet), taking 4 units of cloth per 3 years to prevent unhappy thoughts. Dye does nothing for happiness and is useless unless making a trade good for [[value]]. This totals up to extremely little cloth necessary to keep a fortress running - 268 cloth per year is only about 4 tiles of dedicated rope reed farm, or 8 tiles of dedicated pig tail farm for even a 200-dwarf fortress. (Just don't brew your cloth.) Additional tiles will probably be necessary for cloth to create more bags and possibly rope.

==Approaches==
Some fortresses begin with a single large farm (5x5) with [[plump helmet]]s. However, if you embark with crops and brew them immediately, it is better to start with a few smaller farms (3x3 or 1x5 are common) with a wider variety of crops. Given the small number of dwarves, only a few tiles (about 10 total) are needed for a beginning fortresses, although you can plow a plot and leave it fallow until you have more dwarfpower to spare your farmer to dedicated farming. As the growers [[experience|level up]], farm yields will increase, lowering the need for large plots. Smaller plots with diverse crops can be used, instead. The more tiles of farm plot you have, the more growers (and harvesters) you will need. A single legendary farmer can seed up to about 100 tiles of farmland if they never harvest themselves and the seed stockpile is only a half-dozen tiles from all farm plot tiles. Consider making the seed stockpile in the middle of a ring of farms to save travel time.

Since a tile is "aboveground" if it has EVER been the top non-open space tile, underground and aboveground farms can be placed side-by-side, and the pit you dug to make the aboveground farm can be [[bridge]]d, [[floor]]ed, or [[wall]]ed over.

If you plan to [[farming|fertilize]], farm plots should ideally be one less than a multiple of 4 tiles -- ex. (1x3), (1x7), (3x5), (3x9), (5x7), (7x9)

{{Template:Farming FAQ}}

Farm size calculations

2015-06-29T21:09:37Z

NW Kohaku: /* Approaches */

{{Quality|Fine|21:40, 3 April 2012 (UTC)}}
{{av}}

[[Dwarves]] require approximately 2 units of [[food]] and 5 units of [[drink]] each season. [[Farming]] can produce enough [[crop]]s to satisfy part or all of these requirements. However, be aware that the more and larger your farms are, the more time and effort must be accorded to their maintenance.

==The math==
Your dwarves can plant 1 [[seed]] per tile on each [[farm plot]], and depending on the [[skill]] of the [[grower]], whether the farm plot was [[fertilizer|fertilized]], and random chance, each planted tile will yield a stack of 1-9 (average: 5) plants each harvest cycle. [[Brewing]] always quintuples stack sizes; for example, a stack of [[cave wheat]] [5] is brewed into a [[barrel]] of [[Dwarven beer]] [25] at a [[still]]. Processing [[quarry bush]] plants into quarry bush leaves at a [[farmer's workshop]] also quintuples stack size, as does processing [[sweet pod]]s into [[Dwarven syrup]]. ([[Mill]]ing does ''not'' increase stack size.) These larger stacks are generally not usable directly as food, but can be [[cook]]ed into prepared meals. [[Pig tail]]s and [[plump helmet]]s grow faster than other crops, and as long as the mature plants are harvested promptly, it is not hard to grow multiple crops of either plant each season from the same plot.

{| class="wikitable"
! Plant Name
! Active Seasons
! Days Per Harvest
! Harvests Per Tile Per Season
! Harvests Per Tile Per Year
! Average Plants Harvested Per Tile Per Year
! Average Processed Food/Drink Per Tile Per Year
|-
|Plump helmet
|4
|25
|3
|12
|60
|300
|-
|Pig tail
|2
|25
|3
|6
|30
|150
|-
|Cave wheat
|2
|42
|2
|4
|20
|100
|-
|Sweet pod
|2
|42
|2
|4
|20
|100
|-
|Quarry bush
|3
|42
|2
|6
|30
|150
|-
|Prickle berry
|4
|25
|3
|12
|60
|300
|-
|Wild strawberry
|4
|25
|3
|12
|60
|300
|-
|Longland grass
|4
|25
|3
|12
|60
|300
|-
|Rat weed
|4
|25
|3
|12
|60
|300
|-
|Fisher berry
|4
|25
|3
|12
|60
|300
|-
|Rope reed
|4
|25
|3
|12
|60
|300
|-
|Sliver barb
|4
|25
|3
|12
|60
|300
|-
|Sun berry
|4
|25
|3
|12
|60
|300
|-
|Whip vine
|4
|25
|3
|12
|60
|300
|}

A beginning fortress has 7 dwarves, each of which consumes 7 [[Main:urist|urist]]s of food and drink per dwarf per season, or 196 for the whole fortress for the year. The starting group can theoretically be supported by a single farm tile, but in practice a larger farm will be necessary since a young fortress is unable to use farm tiles to their fullest potential.

A properly-managed and fully-utilized 3x3 plot growing plump helmets can produce an average of up to 2700 units of alcohol per year, enough to provide food (through booze-[[cooking]] with seeds) and drink for a fortress of 95 dwarves. A similar 5x5 plot can produce up to 7500 units of food and drink per year, enough to support 265 dwarves.

This calculation assumes the farm tiles are fertilized, all your planters have Legendary skill, and that there are enough of them to avoid any labor shortages at planting times. The general limitation, then, is not the size of the farm, but the skill of the growers, the availability of seeds and [[potash]] for fertilizer, and careful management of [[labor]], [[stockpiles]], and the food industry to ensure that crops are harvested (rather than left to [[wear|wither]] in the field), are properly stored away from [[vermin]], the plants are processed, and seeds are recovered so that the cycle can continue next season. However, since adding farm tiles is practically free, most overseers find it easier to create larger farms than to optimize production on a smaller plot.

In practice, dwarves require booze variety to avoid bad [[thought]]s and desire food variety to create good thoughts. Additionally, if your dwarves are going to grow textiles (and [[dye]]s) for [[clothing]] they will need more farmland.

==Approaches==
Some fortresses begin with a single large farm (5x5) with [[plump helmet]]s. However, if you embark with crops and brew them immediately, it is better to start with several smaller farms (3x3 or 1x5 are common) with a wider variety of crops. Given the small number of dwarves, only a few tiles (10 total) are needed for a beginning fortresses, although you can plow a plot and leave it fallow until you have more dwarfpower to spare your farmer to dedicated farming. As the growers [[experience|level up]] and farm yields increase the farm can be expanded and newer, smaller farms with different crops can be added to enable new growers to practice their skills. The more tiles of farm plot you have, the more growers (and harvesters) you will need. A single legendary farmer can seed up to about 100 tiles of farmland if they never harvest themselves and the seed stockpile is only a half-dozen tiles from all farm plot tiles. Consider making the seed stockpile in the middle of a ring of farms to save travel time.

If you plan to [[farming|fertilize]], farm plots should ideally be one less than a multiple of 4 tiles -- ex. (1x3), (1x7), (3x5), (3x9), (5x7), (7x9)

{{Template:Farming FAQ}}

Silk farming

2015-06-29T07:02:42Z

NW Kohaku: Testing shows must be active military

{{Quality|Exceptional|23:22, 4 February 2015 (UTC)}}
{{projects}}{{av}}

'''Silk farming''' is the process of harvesting large quantities of silk from [[web]]slinging creatures like [[giant cave spider]]s. Several setups have been devised to farm silk quickly and safely, but successful silk farms have a few traits in common:

# The webslinging creature must be aggressive toward the bait, and willing to web it. Tame giant cave spiders are not willing to web invaders{{verify}}, while wild spiders appear to only be willing to web ''active military'' dwarves. [[forgotten beast|Various other untamable creatures]] remain willing to web most tame animals (with [[cat]]s being a possible exception). Tame spiders are not aggressive toward animals on restraints.
# The webslinging creature must not be able to reach its bait; if it can, the bait (or creature) will die and no further silk will be generated. Spiders can destroy wooden doors but not stone or metal doors. They cannot pass through forbidden doors or doors that have been "tightly closed". Other silk-spewing creatures can destroy all non-[[artifact]] doors, requiring drawbridges or walls for containment
# Web collection cannot occur in sight of wild webslingers or invaders serving as bait; either will cause dwarves to interrupt collection. Drawbridges work well to block line of sight in either case, as webs will not prevent them from raising.

==Simple silk farm==
{{diagram|spaces=yes|color=#888|\
╔═════════╗
║+++++++++║
║+++++++++╠═╗
║+++++++++┼+║
┼++++++++[#080]╥║[#0F0]^║
║++++++++[#080]║[#F00]╬┼╣
║++++++++[#080]║[#F00]╬S║
║++++++++[#080]║[#F00]╬═╝
┼++++++++[#080]╨║
║+++++++++║
║+++++++++║
║+++++++++║
╚═════════╝
}}
# Dig out (and optionally smooth) a sufficiently large room (example shown is 9x11)
# Build a [[cage]] containing an *untamed* spider at the gray "S", and link it to a lever
# Build a '''non-wooden''' [[door]] above the spider cage, and mark it forbidden and pet-inaccessible
# Recommended: build a [[cage trap]] on the green "^" to recapture your spider later
# [[Construction|Construct]] all of the red [[fortification]]s
# Build the green [[bridge]], raising lengthwise to form a long wall.
# Build a [[lever]] somewhere convenient in your fortress and link it to the green bridge
# Pull the lever to release the spider
# Order a *non-ranged* military dwarf to station or patrol in the room (but *not* on the green bridge)
# Raise the green bridge periodically to allow your bait dwarf to escape, then lower it again to resume production
# Your weavers *may* collect webs during production if they have sufficient discipline; if not, leave the green bridge raised while they collect the webs
# Set pull lever on repeat to have automatic production and collection

==High-volume silk farm==

{{diagram|spaces=yes|color=#888|\
z z-1 z-2
╔═════╦┼══╗ ╔═════╗ ╔═════╗
║[#080]╔[#080]═[#080]═[#080]═[#080]╗┼+++║ ║[#0AA]╔[#0AA]═[#0AA]═[#0AA]═[#0AA]╗┼ ║+++++┼
║[#080]║[#080]+[#080]+[#080]+[#080]║[#F00]╬+║[#0F0]^║ ║[#0AA]║[#0AA]+[#0AA]+[#0AA]+[#0AA]║╠═┼╗ ║+++++║
║[#080]║[#080]+[#080]+[#080]+[#080]║[#F00]╬+╠[#888]┼╣ ║[#0AA]║[#0AA]+[#0AA]+[#0AA]+[#0AA]║║++║ ║+++++║
║[#080]║[#080]+[#080]+[#080]+[#080]║[#F00]╬[#FF0]H[#F00]╬[#CCC]S║ ║[#0AA]║[#0AA]+[#0AA]+[#0AA]+[#0AA]║║++║ ║+++++║
║[#080]║[#080]+[#080]+[#080]+[#080]║[#F00]╬+╠═╝ ║[#0AA]║[#0AA]+[#0AA]+[#0AA]+[#0AA]║║++║ ║+++++║
║[#080]║[#080]+[#080]+[#080]+[#080]║[#F00]╬+║ ║[#0AA]║[#0AA]+[#0AA]+[#0AA]+[#0AA]║╠══╝ ║+++++║
║[#080]╚[#080]═[#080]═[#080]═[#080]╝║[#59F]!║ ║[#0AA]╚[#0AA]═[#0AA]═[#0AA]═[#0AA]╝║ ║+++++║
╚═════╩═╝ ╚═════╝ ╚═════╝

}}

# Dig out the three chambers as shown.
# Smooth and carve the red [[fortification]]s.
# [[Channel]] out the areas in green and cyan, linking all three levels
# Build the large green [[bridge]] (retracting) and large cyan bridge (retracting)
# Construct a [[pressure plate]] in a well-traveled area (or a [[repeater]]) and link it to the green bridge
# Build a [[lever]] and link it to the cyan bridge
# Build a [[cage]] containing an *untamed* spider at the gray "S", and link it to a lever
# Build a '''non-wooden''' [[door]] above the spider cage, and mark it forbidden and pet-inaccessible
# Channel the yellow "H", build a [[hatch cover]] there, and link it to a lever. This will allow you to remove the bait dwarf and stop production.
# Recommended: build a [[cage trap]] on the green "^" to recapture your spider later
# Evacuate the upper two chambers and forbid the bridge-access doors
# Pull the lever linked to the cage to release the spider
# Station or order a melee dwarf to patrol to the blue '!'; lock the door after he enters the chamber
# The spider will blast the bait with webs. When the green bridge automatically retracts, the webs will fall and stack on the cyan bridge
# Pull the lever linked to the cyan bridge to drop the stacked webs to the bottom level for collection
# Remember to release your bait dwarf periodically

Note that a simple pit in the harvesting chamber will not work--the bridge is required to cause the "web objects" to drop to the next level (and stack). Because falling items are deadly (a falling web managed to break the spine of one of my aspiring weavers), it is necessary to collect the webs on the "holding" bridge and only drop them into the collection chamber when your weavers are clear. Also, webs "tossed" by the retracting bridge can injure anything they hit, so your bait dwarf may require occasional replacement. One spider can easily keep several weavers busy, and collecting all the webs provides a great opportunity for [[cross-training]].

'''Extra automisation of the silk farm'''
#Station an weredwarf or vampire as spiderbait. Now your melee dwarf do not need to be replaced and can be totaly locked in.

==Notes on exotic webslingers==

Farming silk from other [[forgotten beast|procedurally]] [[titan|generated]] creatures is somewhat more difficult and less rewarding. As level 2 [[building destroyer]]s, these creatures can only be contained by [[bridge]]s or [[artifact]] [[door]]ways. They are also immune to [[trap]]s, making positioning in the farm rather more complicated. Finally, without a value modifier, the collected silk will be equivalent in [[value]] to common [[cave spider]] silk. They do still provide a nearly-inexhaustible source of silk thread, and with some effort their webs can also be used to [[cage trap|cage]] other trap immune creatures. Also, webslingers with modified material properties (e.g. IGNITE_POINT) can produce webs that retain those properties (e.g. fire-safe or magma-safe silk).

Strange mood

2015-06-22T03:28:29Z

NW Kohaku: /* Caveats */

{{Quality|Exceptional|00:23, 18 May 2015 (UTC)}}
{{av}}

{{buggy|bugsection=Bugs}}
{{minorspoiler}}
Periodically, individual dwarves are struck with an idea for a [[legendary artifact]] and enter a '''strange mood'''. Dwarves which enter a strange mood will stop whatever they are doing and pursue the construction of this artifact to the exclusion of all else. They will not stop to eat, drink, sleep, or even run away from dangerous creatures. If they do not manage to begin construction of the artifact within a handful of months, they will go [[#Failure|insane]] and die soon afterward.

Note: All controllable civilizations are currently able to enter strange moods, though in earlier versions of DF the only civilization this applies to is dwarves.

==Overview==

# The conditions necessary for a strange mood to occur are not fully understood, although they may possess even dwarf children.
# The game will pause, center on a dwarf, and announce that the dwarf has entered one of five different types of strange moods. The [[#Types of moods|types of moods]] are listed below. While in a mood, a dwarf will display a blinking exclamation point (see [[Status icon|status icons]]).
# For the duration of the mood, the dwarf will claim a workshop related to the skill that the mood affects (not all skills are eligible), kick out any dwarf who was using it, and render it otherwise unusable until the mood has ended. If a moody dwarf does not claim a workshop, it is because the appropriate workshop does not exist. (See [[#Skills and workshops|skills and workshops]] below to determine which workshop(s) might be required.) A moody dwarf will ''not'' be able to build a needed workshop; another dwarf with the appropriate [[labor]] designation must do so for them, if one is necessary. Furnaces are also counted as a workshop.
# After claiming a workshop, the dwarf will set about collecting the required materials for their artifact. If the dwarf remains idle inside the workshop, it's because they cannot find the right material. Reference the [[#Demands|demands]] section to determine what may be required. Important Note: They will only collect these materials in the order that they require them. In other words, you have to determine where they are on the list of required materials and then provide the next one before they will continue collecting other materials.
# Once all materials have been gathered, the game will once again pause and center, and the moody dwarf will begin construction. Upon completion the dwarf will create a semi-random artifact related to the skill affected and gain [[legendary]] (or higher) status in that skill (unless the mood type is [[#Possessed|possessed]]). See the [[#Skills and workshops|skills and workshops]] for information on which skills can be gained, or the [[#Artifacts created|artifacts created]] section for more details on the artifacts themselves.

== Types of moods ==
For each of the following types of moods, the first message is how the mood is [[Announcement|announced]]; the second message appears in the dwarf's profile when he or she is viewed with the {{K|v}} key. All moody dwarves will have "Strange Mood" listed as their active task and are "quite content", regardless of any recent [[thought]]s they may have had.

=== Fey ===
* {{Gametext|<dwarf> is taken by a fey mood!|7:1}}
: ''Has the aspect of one fey!''

This is the most basic strange mood. Fey dwarves will clearly state their demands when the workshop they are in is examined.

=== Secretive ===
* {{Gametext|<dwarf> withdraws from society...|7:0}}
: ''Peculiarly secretive...''

Secretive moods are the same as fey moods, except a secretive dwarf will sketch pictures of their required materials instead of clearly stating their demands if they cannot find what they need. Descriptions of all these [[#Demands|secretive requirements]] can be seen only by viewing the workshop that the moody dwarf has claimed, with {{k|q}}, and then only while the dwarf is waiting inside it. More than one "picture" is likely; these will cycle through the entire list automatically if any one is not available. (Since materials are gathered ''in order'', it's quite possible that only one of a long list is needed to allow the moody dwarf to continue on their project. If the dwarf has gathered some of the materials (seen as "tasked" when looking at the workshop with {{k|t}}), then the next in the list is what they are looking for.)

=== Possessed ===
* {{Gametext|<dwarf> has been possessed!|5:1}}
: ''Possessed by unknown forces!''

Possessed dwarves have cryptic material requests, and have the unfortunate distinction of not receiving any experience upon successful construction of an artifact. No controllable circumstances lead to a possessed mood instead of one of the more desirable fey or secretive moods. It is pure luck-based. Possessed dwarves will mutter the name of the artifact they are working on (which, under some circumstances, might end up being ''their own name'') once they have all the materials they need.

A possession is the only mood that does '''''not''''' result in a jump in [[experience]].

A possessed dwarf that "keeps muttering <name of the artifact>..." has already gathered everything it needs.

=== Fell ===
* {{Gametext|<dwarf> looses a roaring laughter, fell and terrible!|5:0}}
: ''Has a horrible fell look!''

A dwarf that goes into a fell mood will always take over a [[butcher's shop]] or a [[tanner's shop]]. If neither are available, any other workshop will be used instead. The dwarf will then ''murder'' the nearest dwarf, drag the corpse into the shop and make some sort of object out of dwarf [[leather]] or [[bone]]. Once the artifact is completed, the fell dwarf will become a legendary [[bone carver]] or [[leatherworker]]. Only unhappy dwarves may enter a fell mood.

Amusingly, it seems fell dwarves can murder [[ghost]]s as well.

Aside from the loss of a potentially important dwarf in the wrong place at the wrong time, there doesn't seem to be any downside to a fell mood. The end result is always an artifact and a legendary craftsdwarf. Since the only ingredient used (a dwarf) is available in abundance, a fell mood will only fail if the fell dwarf is completely isolated from other dwarves, or if the proper workshop does not exist.

If no one is around to witness the murder, whichever dwarf Urist McEmo decides to slaughter will be reported as missing some time after his death. If the murder is witnessed, the moody dwarf will be subject to dwarven [[justice]].

=== Macabre ===
* {{Gametext|<dwarf> begins to stalk and brood...|0:1}}
: ''Brooding darkly...''

Macabre moods are similar to fell moods, but the dwarf will not murder a fellow dwarf. A macabre dwarf may require bones, skulls{{verify}}, or vermin remains; if you do not happen to have any, you will have to make some, e.g. by butchering an animal and/or allowing a [[cat]] to go hunting, or let the moody dwarf go insane. Like fell moods, only unhappy dwarves can enter macabre moods.

==Caveats==
* Shells are perhaps the most difficult to obtain material for a strange mood, though there are several {{catlink|Shell|creatures}} that produce shells. Some of these, such as [[armadillo]]s and [[common snapping turtle]]s, are butcherable. Vermin from [[fishing]] are the easiest and most renewable source of shells. [[Pond turtle]]s are common in many embarks in [[murky pool]]s, but usually only appear in small numbers, and can go extinct easily. A stream or river almost guarantees a functionally inexhaustible supply of [[mussel]]s. [[Nautilus]]es can also serve as sources of shells when cleaned at a fishery. Nevertheless, shells are rare and hard to acquire. Currently, the only way of trading for shells is to hope that the [[elven]] caravan brings some tamed shell-producing large creature. Traded [[cave lobster]]s and [[turtle]]s are ''processed'' fish (with the shells already removed). Tamed vermin with shells cannot be butchered for their shells, since the only way to get a vermin's shell is to [[Fish cleaning|clean]] it. Since all shelled non-vermin animals are [[exotic pet|exotic]], only elves will bring them. If you should be fortunate enough to acquire some breeding shelled butcherable animals, it's probably worth keeping a breeding pair around in case of future need. Only dwarves with a [[preference]] for shells will demand shells in a strange mood.
* Should the claimed workshop be a [[magma forge]] and lose power due to insufficient magma beneath it, the mood will fail immediately and the dwarf will go [[insanity|insane]]. Should the forge be in danger of losing power, you should forbid it before it is claimed and wait until it is powered up reliably. Once magma forges are built, at least some dwarves will no longer be satisfied with a regular forge.
* The mood's primary material will only be mentioned ''once'' in the dwarf's requests, even if the dwarf wants more than one unit of it. [http://www.bay12forums.com/smf/index.php?topic=75139.0]
* The item type of the artifact to be created is not decided until the instant the mood ''ends''. Saving (even after a dwarf has begun to gather materials) will allow you to reload and the result may be a different artifact (unless the moody dwarf's preferences force a particular item type). If you want to get an artifact platinum warhammer, make sure to have platinum nearby and/or block access to any other materials. You can reload the artifact creating process, even after the dwarf has gathered most of components by forbidding the claimed items (use {{k|t}} to view the contents of the workshop, select the undesired material, and press {{k|f}} to forbid it). If other items of that type are available, the dwarf will immediately switch to them.
* Requests for bones are actually requests for any kind of bone stacks, not individual bones. Slaughter a puppy. [http://www.bay12forums.com/smf/index.php?topic=105002.0]

== Demands ==
Once a workshop is claimed, the dwarf will begin collecting materials. Each artifact will require 1-3 "base items" and up to 7 additional items for decorations. The dwarf may well need several items of one material! If the moody dwarf remains idle, then the necessary materials are not available. [[Forbid|Forbidden]] items must be reclaimed ({{K|d}} - {{K|b}} - {{K|c}}) before they may be used, but moody dwarves will ignore settings regarding [[economic stone]]. Press {{K|q}} and highlight the workshop to receive a series of clues about what the dwarf needs. Hints that stay active for longer than 2 seconds mean that multiple pieces of that material will be required; each single demand will be displayed for 2 seconds, so if it says "gems... shining" for 6 seconds, 3 gems are demanded. However, the mood's '''primary''' material will always be shown for only 2 seconds even if more than one is required. Materials will always be fetched ''in order'', so if at least one item has already been retrieved (the items will show up with "TSK" ("task") next to them when the workshop is viewed with the {{K|t}} context menu), it will usually be possible to tell what item is required next.

If you want your dwarves to construct their artifacts out of valuable materials instead of whatever useless thing happens to be close at hand, you can selectively forbid types of material through the stocks screen so that only the material you want them to use is available; though this might interfere with the normal crafting operations of your fortress, the disruption is generally short-lived (as long as you remember to unforbid them again afterwards!). You can even forbid something a moody dwarf is carrying (which may be necessary sometimes, since while they are not waiting in the workshop they will not tell you what they need); the dwarf will finish hauling it to the workshop, but then immediately go searching for another. This trick can mean the difference between a bauxite statue decorated with moss agates and a native platinum statue encrusted with diamonds. Be aware that this may not always work - see below for more information.

Burrows allow even better control over a moody dwarf's material usage. Simply by creating a burrow around the claimed workshop and another part over the desired material, a moody dwarf can be controlled without forbidding every single stone in the fortress. A moody dwarf will follow the burrow-definitions just like a regular worker, but be mindful that they will not leave the burrow to get materials that are outside of their assigned burrow. A problem can arise when bones from an outside refuse stockpile are needed by a moody dwarf that is assigned to a burrow.

The various demands are translated here:

:{| class="wikitable" style="text-align:left;width:90%;"
|-
! Material
! Fey
! Secretive
! Possessed
|-
|
| <dwarf> screams "I must have <demand>!"
| <dwarf> sketches pictures of <demand>.
| <dwarf> mutters "<artifact> needs <demand>..."
|-
| [[Stone]]
| rock
| a quarry
| stone... rock
|-
| Stone/metal [[block]]s
| rock blocks
| square blocks
| blocks... bricks
|-
| [[Wood]]
| wood logs
| a forest
| tree... life
|-
| Metal [[bar]]
| metal bars
| shining bars of metal
| bars... metal
|-
| [[Gem]]s (cut)
| cut gems
| cut gems
| gems... shining
|-
| [[Gem]]s (raw)
| rough gems
| rough gems
| rough... color
|-
| Green [[glass]]
| raw green glass
| glass
| raw... green
|-
| Clear glass
| raw clear glass{{verify}}
| glass and burning wood
| raw... clear
|-
| Crystal glass
| raw crystal glass{{verify}}
| rough gems and glass
| raw... crystal
|-
| [[Bone]] [http://www.bay12forums.com/smf/index.php?topic=105002.0;topicseen stack] {{verify}}
| bones
| skeletons
| bones... yes
|-
| [[Shell]]{{verify}}
| shells
| shells
| a shell...
|-
| [[Leather]]
| tanned hides
| stacked leather
| leather... skin
|-
| [[Cloth]] (plant fiber)
| plant cloth
| stacked cloth
| cloth... thread
|-
| [[Cloth]] (silk)
| silk cloth
| stacked cloth
| cloth... thread
|-
| [[Cloth]] (yarn)
| yarn cloth
| stacked cloth
| cloth... thread
|-
| [[Skull]]{{verify}}
| body parts
| death
| a corpse
|}

Dwarves in macabre moods will list their demands in the same fashion as those in fey moods (though with them brooding "Yes. I need <item>." instead of screaming "I must have <item>!"). They may also say "Leave me. I need... things... certain things", in which case they want special items such as [[skull]]s or vermin [[remains]].

Related to the above behavior, moody dwarves demanding rock blocks will also accept blocks forged from metal bars.

*The first item demanded by the dwarf is based on the mood skill being used - stoneworkers (miners, engravers, masons, stone crafters, and mechanics) will demand boulders, woodworkers (carpenters, wood crafters, and bowyers) will demand logs, leatherworkers and tanners will demand leather, weavers and clothiers will demand cloth, metalworkers will demand metal bars, gem cutters/setters will demand rough gems, glassmakers will demand raw glass, and bone carvers will demand bones.
**Metalworkers will demand their favorite type of metal '''if''' you have smelted any bars of it - fey moods will state this outright, while for secretive moods and possessions you will need to check the dwarf's [[preferences]] to see which metal they like. If you have any [[adamantine]] wafers available, then they will demand that instead.
**Weavers and clothiers who have a preference for any type of silk, plant fiber cloth, or yarn will demand that generic type (e.g. a dwarf that likes cave spider silk will require ''any'' type of silk), and a dwarf who likes more than one type of cloth will demand whichever one appears first in their list. If you have any [[adamantine]] cloth available, then they will demand that instead.
**Glassmakers will demand their preferred type of glass, whether you've produced it or not; if they don't prefer any type of glass, they will randomly select one type of glass you've produced (though they will always assume you have created green glass). Note that acquiring raw glass from a caravan does '''not''' count as producing it.
**Dwarves in macabre moods will select either 1 vermin remains, 1 stack of bones, or 1-3 skulls.
**Bone carvers will demand shells if they like a type of shell; if not, they will demand bones.
*The remaining "decoration" items are selected randomly from the following list: wood logs, metal bars, small gems, rock blocks, rough gems, boulders, bones, leather, plant/silk/yarn cloth, or green/clear/crystal glass (based on what you've produced).
**Decoration items will never be the same type as the primary mood material.
**Certain mood professions will also explicitly avoid using certain items for decorations - most of these match up with the primary mood material, but miners, engravers, masons, and stone crafters will additionally avoid requesting rock blocks.
**If you have not produced any raw glass in your fortress, moody dwarves will never request it.
**Dwarves in macabre moods have a 50% chance to request additional remains, bones, or ''nothing'' (in previous versions, they would request additional skulls) instead of one of the above items.
*Gem cutters and gem setters have a 50% chance of only gathering a single rough gem and nothing else, producing a perfect gem with a single decoration.

Once all materials have been gathered, viewing the workshop with {{K|q}} will display a special message depending on the type of mood:
* Fey - "<dwarf> works furiously!"
* Secretive - "<dwarf> works secretly..."
* Possessed - "<dwarf> keeps muttering <artifact>..."
* Macabre - "<dwarf> works, darkly brooding..."
* Fell - "<dwarf> works with menacing fury!"

== The mechanics of moods ==

=== Frequency===
When a fortress is started, an internal counter is set to 1000. Every 100 frames (12 times per day), this counter is decremented by 1, running down to zero in about 3 months. When the counter would ordinarily be decremented when it has already reached zero, there is a 1 in 500 chance that a strange mood will strike. This means that, once all conditions are met and the clock is ticking, while there is approximately a 2.4% chance of a strange mood per day, or a ~52% chance of at least one strange mood per month, there is no guarantee when a mood will strike - might be sooner, might be (almost) never.

=== Conditions ===
In order for a dwarf to be struck with a strange mood, three conditions must be met:
:* There is no currently active strange mood,
:* The maximum number of artifacts is not met,
:* There are at least 20 eligible dwarves ''(see below)'', including dwarves who have already created artifacts.

If all three of these conditions are true, the game may trigger a strange mood according to the frequency.

==== Maximum number of artifacts ====
The maximum number of artifacts in any one fortress is limited by the lower of:
* The number of items created divided by 100.1 Mined-out rock '''does''' count as an "item created", though it is not clear whether bolts or units of drink are counted individually.
* The number of revealed [[subterranean]] tiles divided by 2304 (this is an area equivalent to a 48x48 square). Once you discover and explore the [[cavern]]s and [[magma sea]], this limit becomes largely irrelevant, and using a [[utilities#DFHack|"reveal" utility]] will eliminate it altogether, though strip-mining an area entirely and exposing it to the surface will count ''against'' this.
:1 - actually the sum of all items by type '''and''' by type+subtype+material, divided by 200. Furthermore, destroying items does '''not''' decrement these counters, so casting and mining [[obsidian]] will count toward this.

==== Eligibility ====
The deciding factor for eligibility is a dwarf's actual [[profession]]. ''(Note that "[[Skill#Custom profession labels|custom professions]]" have no effect on this!)'' Thus, dwarves may enter strange moods regardless of what skills they have or don't have, so long as they are of an acceptable profession. Dwarves who have already created an artifact are not eligible to create another, and since every mood ends in either an artifact or death, every dwarf may enter at most one mood. Dwarves who have obtained one or more legendary skills without creating artifacts '''may''' enter strange moods and will simply become even ''more'' legendary.

Dwarves with a [[Soldier#Soldier professions|military profession]] other than "Recruit" '''cannot''' enter moods. Incidental military skills make no difference - eligibility (and weighting) depends purely on the actual ''[[profession]]'' as listed at the time, so soldiers '''can''' enter moods if they are ''off duty'' and thus in Civilian mode. Children may enter moods, but babies will not.

Any other profession is eligible to enter a mood, but not all have the same ''chance'' to enter a mood...

:''('''Note''' - Specifically, and to avoid previous misunderstandings, [[Strand extractor]], [[Clerk]]/[[Administrator]]/[[Trader]], [[Doctor]] (and related), [[Building designer|Architect]], [[Soldier#Recruits|Recruit]] and [[Child]] '''are''' moodable professions.)''

There are several additional factors which will prevent a dwarf from entering a mood:
* Being unable to pick up items ("cannot grasp")
* Being dragged by another unit (off to [[jail]])
* Dragging another unit (leading livestock to a [[cage]], [[chain]], [[pasture]], [[Activity zone#Pit/Pond|pit/pond zone]], or to the [[butcher's shop]])

=== Chance ===
When determining who will have a strange mood, each eligible dwarf is put into a weighted lottery, where the chance of being selected is based on the dwarf's [[profession]]. Most professions receive 6 tickets, but some receive additional tickets to improve their odds.

{| class="wikitable" cellspacing="0" border="2" cellpadding="5"
|-
! Weighting
! Professions

|-
| 21 ||Armorer, Blacksmith, Bone Carver, Clothier, Craftsdwarf, Jeweler, Gem Cutter, Gem Setter, Glassmaker, Leatherworker, Metalcrafter, Metalsmith, Stonecrafter, Weaponsmith, Weaver, Woodcrafter
|-
| 11 ||Bowyer, Carpenter, Stoneworker, Mason, Woodworker
|-
| 6 ||Engraver, Mechanic, Miner, Tanner, & all other [[profession]]s (including Peasant).

|}

:'''''Example:''' What this means is: if you had 21 dwarves, made up of 20 eligible farmers, furnace operators, miners, woodcutters etc. (with 6 chances each) plus one Armorer (with 21 chances), that one Armorer would have a 21 in 141 chance (20 dwarves x 6 chances each = 120 + 21 chances more = 141 total) of the mood striking them. That's about 1 in 7, while the other 20 have a 6 in 141 chance each, or about 1 in 24. The odds are still against the armorer, but much better than for any other single dwarf.''

Note that not every profession is from a moodable skill. A Soaper, Architect, Furnace Operator or Strand Extractor can be taken by a mood, but that will not make those skills legendary, nor will they create an artifact bar of soap, building, bar of metal or wafer of adamantine.

=== Skills and workshops ===

{| class="wikitable sortable" cellpadding="4" style="border:1px solid black;border-collapse:collapse;text-align:left;float:right;margin:0 0 20px 30px;vertical-align:top;"
|-
! Highest skill
! Workshop required
|-
| [[Armorsmith]]
| [[Metalsmith's forge]] (or [[Magma forge]])
|-
| [[Bone carver]]
| [[Craftsdwarf's workshop]]
|-
| [[Bowyer]]
| [[Bowyer's workshop]]
|-
| [[Carpenter]]
| [[Carpenter's workshop]]
|-
| [[Clothier]]
| [[Clothier's shop]]
|-
| [[Engraver]]
| [[Craftsdwarf's workshop]]
|-
| [[Gem cutter]]
| [[Jeweler's workshop]]
|-
| [[Gem setter]]
| [[Jeweler's workshop]]
|-
| [[Glassmaker]]
| [[Glass furnace]] (or [[Magma glass furnace]])
|-
| [[Leatherworker]]
| [[Leather works]]
|-
| [[Mason]]
| [[Mason's workshop]]
|-
| [[Mechanic]]
| [[Mechanic's workshop]]
|-
| [[Metal crafter]]
| [[Metalsmith's forge]] (or [[Magma forge]])
|-
| [[Metalsmith]]
| [[Metalsmith's forge]] (or [[Magma forge]])
|-
| [[Miner]]
| [[Mason's workshop]]
|-
| [[Stone crafter]]
| [[Craftsdwarf's workshop]]
|-
| [[Tanner]]
| [[Leather works]]
|-
| [[Weaponsmith]]
| [[Metalsmith's forge]] (or [[Magma forge]])
|-
| [[Weaver]]
| [[Clothier's shop]]
|-
| [[Wood crafter]]
| [[Craftsdwarf's workshop]]
|-
| <none>
| [[Craftsdwarf's workshop]]
|}

A dwarf will claim a workshop according to their highest applicable skill, and upon completion of the artifact, gain 20,000 [[experience]] in that skill (excepting [[Strange mood#Possessed|possessed]] dwarves). This will give the dwarf a legendary-level [[skill]] (specifically, "legendary+1" or higher, depending on the dwarf's initial skill level). The table to the right describes all applicable skills and their potential workshop requirements - there are only 20 skills that determine the workshop and that can be affected by a mood (sometimes referred to as '''moodable''' skills.) If a dwarf does not possess at least one of the moodable skills listed to the right, they will take over a [[craftsdwarf's workshop]] and gain one of [[bone carver]], [[stone crafter]], or [[wood crafter]] skills, producing an artifact [[craft]].

When selecting the desired mood skill, only the level itself is checked, and if the highest level found is shared by multiple skills, then one will be selected randomly.

This fact can be utilized to maximize the possibility of getting a dwarf with the specific legendary skill you want: since ''non''-moodable skills are ignored, whenever possible make sure that each dwarf's highest ''moodable'' skill is one of those you want. Have all your peasants, [[farmer]]s, non-professional military and other dwarves without any moodable skills do a tiny bit of work in the skill(s) you most want; if a "[[experience|dabbling]]" skill is the highest moodable skill they have, that is the skill that will be used.

[[Weaponsmith]], [[Armorsmith]], [[Bowyer]], [[Leatherworker]], [[Clothier]], and [[Mechanic]] are the only skills that provide a uniquely beneficial item other than an extremely valuable trinket or piece of furniture. Note that artifact furniture is useful for increasing [[room value]].

== Artifacts created ==
The type of artifact created depends on the type of mood, the dwarf's highest moodable skill, and the base material. Masons and miners will always create some kind of stone furniture; bone carvers, a bone or shell object (including furniture); carpenters, a piece of wooden furniture; engravers and stone crafters, a stone craft; metalworkers, metal crafts, weapons, or armor (depending on the type of metalworker); weavers and clothiers, an article of clothing; tanners and leatherworkers, a leather armor or object. If a dwarf has no moodable skills, they will randomly select stone crafting, wood crafting, or bone carving as their mood skill and produce their artifact accordingly. The precise type of craft created is usually somewhat random, but if a dwarf has a personality preference for a particular thing, such as gauntlets or floodgates or crowns, and that thing is an available choice given the dwarf's profession, they are guaranteed to create an object of that type (if multiple preferences match, one will be randomly selected).

The first object grabbed by the dwarf will be the base material; all other materials will be used as [[decoration]]s. If a dwarf grabs a piece of [[chalk]] and makes a statue, for instance, it will be a "chalk statue", but an artifact can potentially include bone, cloth, gems, leather, metal, shell, stone, and wood decorations all at once. In some cases, a moody dwarf will produce an item which normally cannot be made from that material, leading to such odd constructions as an [[obsidian]] [[bed]], [[ruby]] [[floodgate]], or turtle [[shell]] [[cage]], but the actual item types available for each mood type are still very much restricted (e.g. only a glassmaker or jeweler can make a [[window]], and a moody clothier cannot produce an article of clothing that could not normally be made from cloth).

{| class="wikitable" cellpadding="4" style="border:1px solid black;border-collapse:collapse;text-align:left;"
|-
! Mood / Skill
! Artifact type
|-
| [[Armorsmith]]
| Each equipment item with [METAL] (mail shirt, breastplate, leggings, greaves, gauntlet, low boot, high boot, cap, helm, mask), any shield
|-
| [[Bone carver]] (bone)
| Each equipment item with [BARRED] (leggings, greaves, gauntlet, helm), any shield, instrument, toy, door, bed, chair, table, statue, coffer, bin, armor stand, weapon rack, cabinet, coffin, floodgate, hatch cover, grate, chain, cage, animal trap, figurine, amulet, scepter, crown, ring, earring, bracelet, any weapon, any trap component†
|-
| [[Bone carver]] (shell)
| Each equipment item with [SCALED] (leggings, gauntlet, helm), figurine, amulet, crown, ring, earring, bracelet, chain, cage, animal trap, instrument, toy
|-
| [[Bowyer]]
| Crossbow, bow, blowgun
|-
| [[Carpenter]]
| Door, bed, chair, table, statue, chest, bin, armor stand, weapon rack, cabinet, coffin, floodgate, hatch cover, grate, cage, barrel, bucket, animal trap, splint, crutch
|-
| [[Clothier]]
| rowspan=2| Each equipment item with [SOFT] (dress, shirt, tunic, toga, vest, robe, coat, cloak, cape, trousers, loincloth, thong, short skirt, skirt, long skirt, braies, glove, mitten, sock, sandal, shoe, chausses, cap, hood, mask, turban, head veil, face veil, headscarf), bag, rope
|-
| [[Weaver]]
|-
| [[Engraver]]
| Figurine, amulet, scepter, crown, ring, earring, bracelet, goblet, instrument, toy
|-
| Fell Mood
| rowspan=3| Each equipment item with [LEATHER] (dress, shirt, tunic, toga, vest, robe, coat, cloak, cape, armor, trousers, loincloth, thong, short skirt, skirt, long skirt, braies, leggings, glove, mitten, sock, sandal, shoe, chausses, low boot, high boot, cap, hood, mask, turban, head veil, face veil, headscarf, helm), any shield, bag, backpack, quiver, instrument
|-
| [[Leatherworker]]
|-
| [[Tanner]]
|-
| [[Gem cutter]]
| rowspan=3| Perfect gem‡, door, bed, chair, table, statue, box, armor stand, weapon rack, cabinet, coffin, floodgate, hatch cover, grate, figurine, amulet, scepter, crown, ring, earring, bracelet, chain, flask, goblet, cage, barrel, bucket, animal trap, window, instrument, toy
|-
| [[Gem setter]]
|-
| [[Glassmaker]]
|-
| Macabre Mood (vermin remains)
| Amulet, bracelet, earring
|-
| [[Mason]]
| rowspan=2| Door, bed, chair, table, statue, quern, millstone, coffer, armor stand, weapon rack, cabinet, coffin, floodgate, hatch cover, grate
|-
| [[Miner]]
|-
| [[Mechanic]]
| Mechanism
|-
| [[Metal crafter]]
| Figurine, amulet, scepter, crown, ring, earring, bracelet, chain, flask, goblet, instrument, toy
|-
| [[Metalsmith]]
| Door, bed, chair, table, statue, coffer, armor stand, weapon rack, cabinet, anvil, coffin, floodgate, hatch cover, grate, cage, barrel, bucket, animal trap, pipe section†, splint, crutch
|-
| [[Stone crafter]]
| Figurine, amulet, scepter, crown, ring, earring, bracelet, goblet, instrument, toy
|-
| [[Weaponsmith]]
| Any weapon, any trap component†
|-
| [[Wood crafter]]
| Figurine, amulet, scepter, crown, ring, earring, bracelet, goblet, instrument, toy
|}
:† ''chance of selection for this entry is reduced by 90%''
:‡ ''this item will always be made from exactly one rough gem and will never use any additional decoration materials''

If your dwarf does not have a preference for any possible items, the game will randomly select one from the list. Entries with "any" are treated as collective entries with a single chance and will randomly choose a subtype which your civilization is capable of making. This explains why bowyers and clothiers will regularly produce foreign artifacts, while weaponsmiths will not.

== Success ==
Once created, most [[artifact]]s will be available for use just like a normal item of its type. Artifact [[armor]] and [[weapon]]s gain extra bonuses in combat, while artifact clothing is immune to [[wear]]. Artifact mechanisms installed in weapon traps will improve attack rolls. Artifact furniture is useful for raising the value of a [[noble]]'s room. Artifact mechanisms, trap components, or weapons in [[weapon trap|weapon trap]]s can also boost a room's value considerably. Other artifacts that can be used in construction (such as [[barrel]]s, [[bucket]]s, and [[anvil]]s) may be used similarly. Artifact [[door]]s and [[hatch]]es are immune to [[building destroyer]]s. Artifact crafts are currently useless, and artifact [[cage]]s should ''not'' be used to hold hostile creatures--due to a bug they can escape.

Successfully creating an artifact grants a very strong happy [[thought]] (enough to make the creator totally ecstatic for several months) as well as granting the creator partial '''immunity to insanity''' - even if your fortress enters a [[tantrum]] spiral, any dwarf who has created an artifact is exempt from going [[insane]] due to prolonged unhappiness.

== Failure ==
If you can't provide the desired workshop and all the required component materials within a couple of months, the dwarf will go [[insanity|insane]], which cancels the mood and the artifact. As if that's not bad enough, any dwarf who goes insane will soon die, one way or another.

A dwarf who is '''stark raving mad''' or '''melancholy''' is harmless to others (until they die and start a [[tantrum]] spiral), but a '''berserk''' dwarf will attack other dwarves and possibly pull levers at random. You may want to station a squad nearby or assign a few war dogs to the dwarf on the chance that they will lash out. If you build your workshops inside enclosed rooms with doors you can also lock the moody dwarf in the room until he or she starves. In extreme cases, building a wall around an open workshop is the best precaution.

==Bugs==
There are many bugs reported related to moody dwarves. As has been the case in 40d, most turned out to be (understandable) failures of the player to grasp the mechanics of artifact creation and demands. ([http://bay12games.com/dwarves/mantisbt/view_all_bug_page.php Bug tracker])
* Moody dwarves don't respect burrows when grabbing a workshop, but ''do'' when looking for items. {{bug|1416}} If a dwarf's claimed workshop is outside their assigned burrow, the dwarf will continue to grab materials until all materials of the needed type are exhausted within the assigned burrow. (See [[Main:Planepacked|Planepacked]]).
* If a dwarf dies due to failing to complete an artifact, a memorial made to the dwarf will read that the dwarf did create it, despite the failure, and will even list the name of the artifact that never came to be. {{bug|3640}}
* When producing an item that is normally made in pairs (gloves, boots, etc.), only a single artifact will be created.

== Troubleshooting ==

'''Problem''': Moody dwarf does not claim a workshop
:'''Solution''': Check for highest moodable skill and build the corresponding workshop. If no moodable skills, build a craftsdwarf's workshop. Once [[magma forge]]s have been built, some dwarves may demand to work at a magma forge. Note that [[forbid]]den workshops cannot be claimed.

'''Problem''': Moody dwarf waits in claimed workshop
:'''Solution''': Desired material is unavailable. Determine which material is requested next (materials are collected in the same order as shown in the dwarf's request list), and make some available, if possible. Note that dwarves with [[preference]]s may demand a specific type of material ([[brass]] bars or [[yarn]] cloth, for example). [[Forbid]]den and inaccessible materials cannot be collected, nor can material located outside the moody dwarf's [[burrow]].

'''Problem''': Moody dwarf collects base material continually
:'''Solution''': The claimed workshop is outside of the dwarf's [[burrow]], resulting in the [[Main:Planepacked|Planepacked]] glitch. Add the workshop to the burrow or remove the dwarf from the burrow to finish collecting materials.

'''Problem''': No dwarf has entered a mood for a long time
:'''Solution''': Strange moods require at least 20 dwarves; if you have that many you've probably hit one of the two caps. Exploring the caverns can increase the number of revealed tiles very quickly, while [[craft]]ing [[goblet]]s will quickly raise your item count; [[exploratory mining]] will count toward ''both'' caps, simultaneously revealing tiles and producing boulders, though slower than exploring or crafting. Exposing excavated terrain to the sky is counterproductive, as it will '''lower''' your artifact cap (since the cap only counts revealed ''subterranean'' tiles).

{{Category|Dwarves}}

Strange mood

2015-06-22T03:27:41Z

NW Kohaku: /* Caveats */

{{Quality|Exceptional|00:23, 18 May 2015 (UTC)}}
{{av}}

{{buggy|bugsection=Bugs}}
{{minorspoiler}}
Periodically, individual dwarves are struck with an idea for a [[legendary artifact]] and enter a '''strange mood'''. Dwarves which enter a strange mood will stop whatever they are doing and pursue the construction of this artifact to the exclusion of all else. They will not stop to eat, drink, sleep, or even run away from dangerous creatures. If they do not manage to begin construction of the artifact within a handful of months, they will go [[#Failure|insane]] and die soon afterward.

Note: All controllable civilizations are currently able to enter strange moods, though in earlier versions of DF the only civilization this applies to is dwarves.

==Overview==

# The conditions necessary for a strange mood to occur are not fully understood, although they may possess even dwarf children.
# The game will pause, center on a dwarf, and announce that the dwarf has entered one of five different types of strange moods. The [[#Types of moods|types of moods]] are listed below. While in a mood, a dwarf will display a blinking exclamation point (see [[Status icon|status icons]]).
# For the duration of the mood, the dwarf will claim a workshop related to the skill that the mood affects (not all skills are eligible), kick out any dwarf who was using it, and render it otherwise unusable until the mood has ended. If a moody dwarf does not claim a workshop, it is because the appropriate workshop does not exist. (See [[#Skills and workshops|skills and workshops]] below to determine which workshop(s) might be required.) A moody dwarf will ''not'' be able to build a needed workshop; another dwarf with the appropriate [[labor]] designation must do so for them, if one is necessary. Furnaces are also counted as a workshop.
# After claiming a workshop, the dwarf will set about collecting the required materials for their artifact. If the dwarf remains idle inside the workshop, it's because they cannot find the right material. Reference the [[#Demands|demands]] section to determine what may be required. Important Note: They will only collect these materials in the order that they require them. In other words, you have to determine where they are on the list of required materials and then provide the next one before they will continue collecting other materials.
# Once all materials have been gathered, the game will once again pause and center, and the moody dwarf will begin construction. Upon completion the dwarf will create a semi-random artifact related to the skill affected and gain [[legendary]] (or higher) status in that skill (unless the mood type is [[#Possessed|possessed]]). See the [[#Skills and workshops|skills and workshops]] for information on which skills can be gained, or the [[#Artifacts created|artifacts created]] section for more details on the artifacts themselves.

== Types of moods ==
For each of the following types of moods, the first message is how the mood is [[Announcement|announced]]; the second message appears in the dwarf's profile when he or she is viewed with the {{K|v}} key. All moody dwarves will have "Strange Mood" listed as their active task and are "quite content", regardless of any recent [[thought]]s they may have had.

=== Fey ===
* {{Gametext|<dwarf> is taken by a fey mood!|7:1}}
: ''Has the aspect of one fey!''

This is the most basic strange mood. Fey dwarves will clearly state their demands when the workshop they are in is examined.

=== Secretive ===
* {{Gametext|<dwarf> withdraws from society...|7:0}}
: ''Peculiarly secretive...''

Secretive moods are the same as fey moods, except a secretive dwarf will sketch pictures of their required materials instead of clearly stating their demands if they cannot find what they need. Descriptions of all these [[#Demands|secretive requirements]] can be seen only by viewing the workshop that the moody dwarf has claimed, with {{k|q}}, and then only while the dwarf is waiting inside it. More than one "picture" is likely; these will cycle through the entire list automatically if any one is not available. (Since materials are gathered ''in order'', it's quite possible that only one of a long list is needed to allow the moody dwarf to continue on their project. If the dwarf has gathered some of the materials (seen as "tasked" when looking at the workshop with {{k|t}}), then the next in the list is what they are looking for.)

=== Possessed ===
* {{Gametext|<dwarf> has been possessed!|5:1}}
: ''Possessed by unknown forces!''

Possessed dwarves have cryptic material requests, and have the unfortunate distinction of not receiving any experience upon successful construction of an artifact. No controllable circumstances lead to a possessed mood instead of one of the more desirable fey or secretive moods. It is pure luck-based. Possessed dwarves will mutter the name of the artifact they are working on (which, under some circumstances, might end up being ''their own name'') once they have all the materials they need.

A possession is the only mood that does '''''not''''' result in a jump in [[experience]].

A possessed dwarf that "keeps muttering <name of the artifact>..." has already gathered everything it needs.

=== Fell ===
* {{Gametext|<dwarf> looses a roaring laughter, fell and terrible!|5:0}}
: ''Has a horrible fell look!''

A dwarf that goes into a fell mood will always take over a [[butcher's shop]] or a [[tanner's shop]]. If neither are available, any other workshop will be used instead. The dwarf will then ''murder'' the nearest dwarf, drag the corpse into the shop and make some sort of object out of dwarf [[leather]] or [[bone]]. Once the artifact is completed, the fell dwarf will become a legendary [[bone carver]] or [[leatherworker]]. Only unhappy dwarves may enter a fell mood.

Amusingly, it seems fell dwarves can murder [[ghost]]s as well.

Aside from the loss of a potentially important dwarf in the wrong place at the wrong time, there doesn't seem to be any downside to a fell mood. The end result is always an artifact and a legendary craftsdwarf. Since the only ingredient used (a dwarf) is available in abundance, a fell mood will only fail if the fell dwarf is completely isolated from other dwarves, or if the proper workshop does not exist.

If no one is around to witness the murder, whichever dwarf Urist McEmo decides to slaughter will be reported as missing some time after his death. If the murder is witnessed, the moody dwarf will be subject to dwarven [[justice]].

=== Macabre ===
* {{Gametext|<dwarf> begins to stalk and brood...|0:1}}
: ''Brooding darkly...''

Macabre moods are similar to fell moods, but the dwarf will not murder a fellow dwarf. A macabre dwarf may require bones, skulls{{verify}}, or vermin remains; if you do not happen to have any, you will have to make some, e.g. by butchering an animal and/or allowing a [[cat]] to go hunting, or let the moody dwarf go insane. Like fell moods, only unhappy dwarves can enter macabre moods.

==Caveats==
* Shells are perhaps the most difficult to obtain material for a strange mood, though there are several {{catlink|Shell|creatures}} that produce shells. Some of these, such as [[armadillo]]s and [[common snapping turtle]]s, are butcherable. Vermin from [[fishing]] are the easiest and most renewable source of shells. [[Pond turtle]]s are common in many embarks in [[murky pools]], but usually only appear in small numbers, and can go extinct easily. A stream or river almost guarantees a functionally inexhaustible supply of [[mussel]]s. [[Nautilus]]es can also serve as sources of shells when cleaned at a fishery. Nevertheless, shells are rare and hard to acquire. Currently, the only way of trading for shells is to hope that the [[elven]] caravan brings some tamed shell-producing large creature. Traded [[cave lobster]]s and [[turtle]]s are ''processed'' fish (with the shells already removed). Tamed vermin with shells cannot be butchered for their shells, since the only way to get a vermin's shell is to [[Fish cleaning|clean]] it. Since all shelled non-vermin animals are [[exotic pet|exotic]], only elves will bring them. If you should be fortunate enough to acquire some breeding shelled butcherable animals, it's probably worth keeping a breeding pair around in case of future need. Only dwarves with a [[preference]] for shells will demand shells in a strange mood.
* Should the claimed workshop be a [[magma forge]] and lose power due to insufficient magma beneath it, the mood will fail immediately and the dwarf will go [[insanity|insane]]. Should the forge be in danger of losing power, you should forbid it before it is claimed and wait until it is powered up reliably. Once magma forges are built, at least some dwarves will no longer be satisfied with a regular forge.
* The mood's primary material will only be mentioned ''once'' in the dwarf's requests, even if the dwarf wants more than one unit of it. [http://www.bay12forums.com/smf/index.php?topic=75139.0]
* The item type of the artifact to be created is not decided until the instant the mood ''ends''. Saving (even after a dwarf has begun to gather materials) will allow you to reload and the result may be a different artifact (unless the moody dwarf's preferences force a particular item type). If you want to get an artifact platinum warhammer, make sure to have platinum nearby and/or block access to any other materials. You can reload the artifact creating process, even after the dwarf has gathered most of components by forbidding the claimed items (use {{k|t}} to view the contents of the workshop, select the undesired material, and press {{k|f}} to forbid it). If other items of that type are available, the dwarf will immediately switch to them.
* Requests for bones are actually requests for any kind of bone stacks, not individual bones. Slaughter a puppy. [http://www.bay12forums.com/smf/index.php?topic=105002.0]

== Demands ==
Once a workshop is claimed, the dwarf will begin collecting materials. Each artifact will require 1-3 "base items" and up to 7 additional items for decorations. The dwarf may well need several items of one material! If the moody dwarf remains idle, then the necessary materials are not available. [[Forbid|Forbidden]] items must be reclaimed ({{K|d}} - {{K|b}} - {{K|c}}) before they may be used, but moody dwarves will ignore settings regarding [[economic stone]]. Press {{K|q}} and highlight the workshop to receive a series of clues about what the dwarf needs. Hints that stay active for longer than 2 seconds mean that multiple pieces of that material will be required; each single demand will be displayed for 2 seconds, so if it says "gems... shining" for 6 seconds, 3 gems are demanded. However, the mood's '''primary''' material will always be shown for only 2 seconds even if more than one is required. Materials will always be fetched ''in order'', so if at least one item has already been retrieved (the items will show up with "TSK" ("task") next to them when the workshop is viewed with the {{K|t}} context menu), it will usually be possible to tell what item is required next.

If you want your dwarves to construct their artifacts out of valuable materials instead of whatever useless thing happens to be close at hand, you can selectively forbid types of material through the stocks screen so that only the material you want them to use is available; though this might interfere with the normal crafting operations of your fortress, the disruption is generally short-lived (as long as you remember to unforbid them again afterwards!). You can even forbid something a moody dwarf is carrying (which may be necessary sometimes, since while they are not waiting in the workshop they will not tell you what they need); the dwarf will finish hauling it to the workshop, but then immediately go searching for another. This trick can mean the difference between a bauxite statue decorated with moss agates and a native platinum statue encrusted with diamonds. Be aware that this may not always work - see below for more information.

Burrows allow even better control over a moody dwarf's material usage. Simply by creating a burrow around the claimed workshop and another part over the desired material, a moody dwarf can be controlled without forbidding every single stone in the fortress. A moody dwarf will follow the burrow-definitions just like a regular worker, but be mindful that they will not leave the burrow to get materials that are outside of their assigned burrow. A problem can arise when bones from an outside refuse stockpile are needed by a moody dwarf that is assigned to a burrow.

The various demands are translated here:

:{| class="wikitable" style="text-align:left;width:90%;"
|-
! Material
! Fey
! Secretive
! Possessed
|-
|
| <dwarf> screams "I must have <demand>!"
| <dwarf> sketches pictures of <demand>.
| <dwarf> mutters "<artifact> needs <demand>..."
|-
| [[Stone]]
| rock
| a quarry
| stone... rock
|-
| Stone/metal [[block]]s
| rock blocks
| square blocks
| blocks... bricks
|-
| [[Wood]]
| wood logs
| a forest
| tree... life
|-
| Metal [[bar]]
| metal bars
| shining bars of metal
| bars... metal
|-
| [[Gem]]s (cut)
| cut gems
| cut gems
| gems... shining
|-
| [[Gem]]s (raw)
| rough gems
| rough gems
| rough... color
|-
| Green [[glass]]
| raw green glass
| glass
| raw... green
|-
| Clear glass
| raw clear glass{{verify}}
| glass and burning wood
| raw... clear
|-
| Crystal glass
| raw crystal glass{{verify}}
| rough gems and glass
| raw... crystal
|-
| [[Bone]] [http://www.bay12forums.com/smf/index.php?topic=105002.0;topicseen stack] {{verify}}
| bones
| skeletons
| bones... yes
|-
| [[Shell]]{{verify}}
| shells
| shells
| a shell...
|-
| [[Leather]]
| tanned hides
| stacked leather
| leather... skin
|-
| [[Cloth]] (plant fiber)
| plant cloth
| stacked cloth
| cloth... thread
|-
| [[Cloth]] (silk)
| silk cloth
| stacked cloth
| cloth... thread
|-
| [[Cloth]] (yarn)
| yarn cloth
| stacked cloth
| cloth... thread
|-
| [[Skull]]{{verify}}
| body parts
| death
| a corpse
|}

Dwarves in macabre moods will list their demands in the same fashion as those in fey moods (though with them brooding "Yes. I need <item>." instead of screaming "I must have <item>!"). They may also say "Leave me. I need... things... certain things", in which case they want special items such as [[skull]]s or vermin [[remains]].

Related to the above behavior, moody dwarves demanding rock blocks will also accept blocks forged from metal bars.

*The first item demanded by the dwarf is based on the mood skill being used - stoneworkers (miners, engravers, masons, stone crafters, and mechanics) will demand boulders, woodworkers (carpenters, wood crafters, and bowyers) will demand logs, leatherworkers and tanners will demand leather, weavers and clothiers will demand cloth, metalworkers will demand metal bars, gem cutters/setters will demand rough gems, glassmakers will demand raw glass, and bone carvers will demand bones.
**Metalworkers will demand their favorite type of metal '''if''' you have smelted any bars of it - fey moods will state this outright, while for secretive moods and possessions you will need to check the dwarf's [[preferences]] to see which metal they like. If you have any [[adamantine]] wafers available, then they will demand that instead.
**Weavers and clothiers who have a preference for any type of silk, plant fiber cloth, or yarn will demand that generic type (e.g. a dwarf that likes cave spider silk will require ''any'' type of silk), and a dwarf who likes more than one type of cloth will demand whichever one appears first in their list. If you have any [[adamantine]] cloth available, then they will demand that instead.
**Glassmakers will demand their preferred type of glass, whether you've produced it or not; if they don't prefer any type of glass, they will randomly select one type of glass you've produced (though they will always assume you have created green glass). Note that acquiring raw glass from a caravan does '''not''' count as producing it.
**Dwarves in macabre moods will select either 1 vermin remains, 1 stack of bones, or 1-3 skulls.
**Bone carvers will demand shells if they like a type of shell; if not, they will demand bones.
*The remaining "decoration" items are selected randomly from the following list: wood logs, metal bars, small gems, rock blocks, rough gems, boulders, bones, leather, plant/silk/yarn cloth, or green/clear/crystal glass (based on what you've produced).
**Decoration items will never be the same type as the primary mood material.
**Certain mood professions will also explicitly avoid using certain items for decorations - most of these match up with the primary mood material, but miners, engravers, masons, and stone crafters will additionally avoid requesting rock blocks.
**If you have not produced any raw glass in your fortress, moody dwarves will never request it.
**Dwarves in macabre moods have a 50% chance to request additional remains, bones, or ''nothing'' (in previous versions, they would request additional skulls) instead of one of the above items.
*Gem cutters and gem setters have a 50% chance of only gathering a single rough gem and nothing else, producing a perfect gem with a single decoration.

Once all materials have been gathered, viewing the workshop with {{K|q}} will display a special message depending on the type of mood:
* Fey - "<dwarf> works furiously!"
* Secretive - "<dwarf> works secretly..."
* Possessed - "<dwarf> keeps muttering <artifact>..."
* Macabre - "<dwarf> works, darkly brooding..."
* Fell - "<dwarf> works with menacing fury!"

== The mechanics of moods ==

=== Frequency===
When a fortress is started, an internal counter is set to 1000. Every 100 frames (12 times per day), this counter is decremented by 1, running down to zero in about 3 months. When the counter would ordinarily be decremented when it has already reached zero, there is a 1 in 500 chance that a strange mood will strike. This means that, once all conditions are met and the clock is ticking, while there is approximately a 2.4% chance of a strange mood per day, or a ~52% chance of at least one strange mood per month, there is no guarantee when a mood will strike - might be sooner, might be (almost) never.

=== Conditions ===
In order for a dwarf to be struck with a strange mood, three conditions must be met:
:* There is no currently active strange mood,
:* The maximum number of artifacts is not met,
:* There are at least 20 eligible dwarves ''(see below)'', including dwarves who have already created artifacts.

If all three of these conditions are true, the game may trigger a strange mood according to the frequency.

==== Maximum number of artifacts ====
The maximum number of artifacts in any one fortress is limited by the lower of:
* The number of items created divided by 100.1 Mined-out rock '''does''' count as an "item created", though it is not clear whether bolts or units of drink are counted individually.
* The number of revealed [[subterranean]] tiles divided by 2304 (this is an area equivalent to a 48x48 square). Once you discover and explore the [[cavern]]s and [[magma sea]], this limit becomes largely irrelevant, and using a [[utilities#DFHack|"reveal" utility]] will eliminate it altogether, though strip-mining an area entirely and exposing it to the surface will count ''against'' this.
:1 - actually the sum of all items by type '''and''' by type+subtype+material, divided by 200. Furthermore, destroying items does '''not''' decrement these counters, so casting and mining [[obsidian]] will count toward this.

==== Eligibility ====
The deciding factor for eligibility is a dwarf's actual [[profession]]. ''(Note that "[[Skill#Custom profession labels|custom professions]]" have no effect on this!)'' Thus, dwarves may enter strange moods regardless of what skills they have or don't have, so long as they are of an acceptable profession. Dwarves who have already created an artifact are not eligible to create another, and since every mood ends in either an artifact or death, every dwarf may enter at most one mood. Dwarves who have obtained one or more legendary skills without creating artifacts '''may''' enter strange moods and will simply become even ''more'' legendary.

Dwarves with a [[Soldier#Soldier professions|military profession]] other than "Recruit" '''cannot''' enter moods. Incidental military skills make no difference - eligibility (and weighting) depends purely on the actual ''[[profession]]'' as listed at the time, so soldiers '''can''' enter moods if they are ''off duty'' and thus in Civilian mode. Children may enter moods, but babies will not.

Any other profession is eligible to enter a mood, but not all have the same ''chance'' to enter a mood...

:''('''Note''' - Specifically, and to avoid previous misunderstandings, [[Strand extractor]], [[Clerk]]/[[Administrator]]/[[Trader]], [[Doctor]] (and related), [[Building designer|Architect]], [[Soldier#Recruits|Recruit]] and [[Child]] '''are''' moodable professions.)''

There are several additional factors which will prevent a dwarf from entering a mood:
* Being unable to pick up items ("cannot grasp")
* Being dragged by another unit (off to [[jail]])
* Dragging another unit (leading livestock to a [[cage]], [[chain]], [[pasture]], [[Activity zone#Pit/Pond|pit/pond zone]], or to the [[butcher's shop]])

=== Chance ===
When determining who will have a strange mood, each eligible dwarf is put into a weighted lottery, where the chance of being selected is based on the dwarf's [[profession]]. Most professions receive 6 tickets, but some receive additional tickets to improve their odds.

{| class="wikitable" cellspacing="0" border="2" cellpadding="5"
|-
! Weighting
! Professions

|-
| 21 ||Armorer, Blacksmith, Bone Carver, Clothier, Craftsdwarf, Jeweler, Gem Cutter, Gem Setter, Glassmaker, Leatherworker, Metalcrafter, Metalsmith, Stonecrafter, Weaponsmith, Weaver, Woodcrafter
|-
| 11 ||Bowyer, Carpenter, Stoneworker, Mason, Woodworker
|-
| 6 ||Engraver, Mechanic, Miner, Tanner, & all other [[profession]]s (including Peasant).

|}

:'''''Example:''' What this means is: if you had 21 dwarves, made up of 20 eligible farmers, furnace operators, miners, woodcutters etc. (with 6 chances each) plus one Armorer (with 21 chances), that one Armorer would have a 21 in 141 chance (20 dwarves x 6 chances each = 120 + 21 chances more = 141 total) of the mood striking them. That's about 1 in 7, while the other 20 have a 6 in 141 chance each, or about 1 in 24. The odds are still against the armorer, but much better than for any other single dwarf.''

Note that not every profession is from a moodable skill. A Soaper, Architect, Furnace Operator or Strand Extractor can be taken by a mood, but that will not make those skills legendary, nor will they create an artifact bar of soap, building, bar of metal or wafer of adamantine.

=== Skills and workshops ===

{| class="wikitable sortable" cellpadding="4" style="border:1px solid black;border-collapse:collapse;text-align:left;float:right;margin:0 0 20px 30px;vertical-align:top;"
|-
! Highest skill
! Workshop required
|-
| [[Armorsmith]]
| [[Metalsmith's forge]] (or [[Magma forge]])
|-
| [[Bone carver]]
| [[Craftsdwarf's workshop]]
|-
| [[Bowyer]]
| [[Bowyer's workshop]]
|-
| [[Carpenter]]
| [[Carpenter's workshop]]
|-
| [[Clothier]]
| [[Clothier's shop]]
|-
| [[Engraver]]
| [[Craftsdwarf's workshop]]
|-
| [[Gem cutter]]
| [[Jeweler's workshop]]
|-
| [[Gem setter]]
| [[Jeweler's workshop]]
|-
| [[Glassmaker]]
| [[Glass furnace]] (or [[Magma glass furnace]])
|-
| [[Leatherworker]]
| [[Leather works]]
|-
| [[Mason]]
| [[Mason's workshop]]
|-
| [[Mechanic]]
| [[Mechanic's workshop]]
|-
| [[Metal crafter]]
| [[Metalsmith's forge]] (or [[Magma forge]])
|-
| [[Metalsmith]]
| [[Metalsmith's forge]] (or [[Magma forge]])
|-
| [[Miner]]
| [[Mason's workshop]]
|-
| [[Stone crafter]]
| [[Craftsdwarf's workshop]]
|-
| [[Tanner]]
| [[Leather works]]
|-
| [[Weaponsmith]]
| [[Metalsmith's forge]] (or [[Magma forge]])
|-
| [[Weaver]]
| [[Clothier's shop]]
|-
| [[Wood crafter]]
| [[Craftsdwarf's workshop]]
|-
| <none>
| [[Craftsdwarf's workshop]]
|}

A dwarf will claim a workshop according to their highest applicable skill, and upon completion of the artifact, gain 20,000 [[experience]] in that skill (excepting [[Strange mood#Possessed|possessed]] dwarves). This will give the dwarf a legendary-level [[skill]] (specifically, "legendary+1" or higher, depending on the dwarf's initial skill level). The table to the right describes all applicable skills and their potential workshop requirements - there are only 20 skills that determine the workshop and that can be affected by a mood (sometimes referred to as '''moodable''' skills.) If a dwarf does not possess at least one of the moodable skills listed to the right, they will take over a [[craftsdwarf's workshop]] and gain one of [[bone carver]], [[stone crafter]], or [[wood crafter]] skills, producing an artifact [[craft]].

When selecting the desired mood skill, only the level itself is checked, and if the highest level found is shared by multiple skills, then one will be selected randomly.

This fact can be utilized to maximize the possibility of getting a dwarf with the specific legendary skill you want: since ''non''-moodable skills are ignored, whenever possible make sure that each dwarf's highest ''moodable'' skill is one of those you want. Have all your peasants, [[farmer]]s, non-professional military and other dwarves without any moodable skills do a tiny bit of work in the skill(s) you most want; if a "[[experience|dabbling]]" skill is the highest moodable skill they have, that is the skill that will be used.

[[Weaponsmith]], [[Armorsmith]], [[Bowyer]], [[Leatherworker]], [[Clothier]], and [[Mechanic]] are the only skills that provide a uniquely beneficial item other than an extremely valuable trinket or piece of furniture. Note that artifact furniture is useful for increasing [[room value]].

== Artifacts created ==
The type of artifact created depends on the type of mood, the dwarf's highest moodable skill, and the base material. Masons and miners will always create some kind of stone furniture; bone carvers, a bone or shell object (including furniture); carpenters, a piece of wooden furniture; engravers and stone crafters, a stone craft; metalworkers, metal crafts, weapons, or armor (depending on the type of metalworker); weavers and clothiers, an article of clothing; tanners and leatherworkers, a leather armor or object. If a dwarf has no moodable skills, they will randomly select stone crafting, wood crafting, or bone carving as their mood skill and produce their artifact accordingly. The precise type of craft created is usually somewhat random, but if a dwarf has a personality preference for a particular thing, such as gauntlets or floodgates or crowns, and that thing is an available choice given the dwarf's profession, they are guaranteed to create an object of that type (if multiple preferences match, one will be randomly selected).

The first object grabbed by the dwarf will be the base material; all other materials will be used as [[decoration]]s. If a dwarf grabs a piece of [[chalk]] and makes a statue, for instance, it will be a "chalk statue", but an artifact can potentially include bone, cloth, gems, leather, metal, shell, stone, and wood decorations all at once. In some cases, a moody dwarf will produce an item which normally cannot be made from that material, leading to such odd constructions as an [[obsidian]] [[bed]], [[ruby]] [[floodgate]], or turtle [[shell]] [[cage]], but the actual item types available for each mood type are still very much restricted (e.g. only a glassmaker or jeweler can make a [[window]], and a moody clothier cannot produce an article of clothing that could not normally be made from cloth).

{| class="wikitable" cellpadding="4" style="border:1px solid black;border-collapse:collapse;text-align:left;"
|-
! Mood / Skill
! Artifact type
|-
| [[Armorsmith]]
| Each equipment item with [METAL] (mail shirt, breastplate, leggings, greaves, gauntlet, low boot, high boot, cap, helm, mask), any shield
|-
| [[Bone carver]] (bone)
| Each equipment item with [BARRED] (leggings, greaves, gauntlet, helm), any shield, instrument, toy, door, bed, chair, table, statue, coffer, bin, armor stand, weapon rack, cabinet, coffin, floodgate, hatch cover, grate, chain, cage, animal trap, figurine, amulet, scepter, crown, ring, earring, bracelet, any weapon, any trap component†
|-
| [[Bone carver]] (shell)
| Each equipment item with [SCALED] (leggings, gauntlet, helm), figurine, amulet, crown, ring, earring, bracelet, chain, cage, animal trap, instrument, toy
|-
| [[Bowyer]]
| Crossbow, bow, blowgun
|-
| [[Carpenter]]
| Door, bed, chair, table, statue, chest, bin, armor stand, weapon rack, cabinet, coffin, floodgate, hatch cover, grate, cage, barrel, bucket, animal trap, splint, crutch
|-
| [[Clothier]]
| rowspan=2| Each equipment item with [SOFT] (dress, shirt, tunic, toga, vest, robe, coat, cloak, cape, trousers, loincloth, thong, short skirt, skirt, long skirt, braies, glove, mitten, sock, sandal, shoe, chausses, cap, hood, mask, turban, head veil, face veil, headscarf), bag, rope
|-
| [[Weaver]]
|-
| [[Engraver]]
| Figurine, amulet, scepter, crown, ring, earring, bracelet, goblet, instrument, toy
|-
| Fell Mood
| rowspan=3| Each equipment item with [LEATHER] (dress, shirt, tunic, toga, vest, robe, coat, cloak, cape, armor, trousers, loincloth, thong, short skirt, skirt, long skirt, braies, leggings, glove, mitten, sock, sandal, shoe, chausses, low boot, high boot, cap, hood, mask, turban, head veil, face veil, headscarf, helm), any shield, bag, backpack, quiver, instrument
|-
| [[Leatherworker]]
|-
| [[Tanner]]
|-
| [[Gem cutter]]
| rowspan=3| Perfect gem‡, door, bed, chair, table, statue, box, armor stand, weapon rack, cabinet, coffin, floodgate, hatch cover, grate, figurine, amulet, scepter, crown, ring, earring, bracelet, chain, flask, goblet, cage, barrel, bucket, animal trap, window, instrument, toy
|-
| [[Gem setter]]
|-
| [[Glassmaker]]
|-
| Macabre Mood (vermin remains)
| Amulet, bracelet, earring
|-
| [[Mason]]
| rowspan=2| Door, bed, chair, table, statue, quern, millstone, coffer, armor stand, weapon rack, cabinet, coffin, floodgate, hatch cover, grate
|-
| [[Miner]]
|-
| [[Mechanic]]
| Mechanism
|-
| [[Metal crafter]]
| Figurine, amulet, scepter, crown, ring, earring, bracelet, chain, flask, goblet, instrument, toy
|-
| [[Metalsmith]]
| Door, bed, chair, table, statue, coffer, armor stand, weapon rack, cabinet, anvil, coffin, floodgate, hatch cover, grate, cage, barrel, bucket, animal trap, pipe section†, splint, crutch
|-
| [[Stone crafter]]
| Figurine, amulet, scepter, crown, ring, earring, bracelet, goblet, instrument, toy
|-
| [[Weaponsmith]]
| Any weapon, any trap component†
|-
| [[Wood crafter]]
| Figurine, amulet, scepter, crown, ring, earring, bracelet, goblet, instrument, toy
|}
:† ''chance of selection for this entry is reduced by 90%''
:‡ ''this item will always be made from exactly one rough gem and will never use any additional decoration materials''

If your dwarf does not have a preference for any possible items, the game will randomly select one from the list. Entries with "any" are treated as collective entries with a single chance and will randomly choose a subtype which your civilization is capable of making. This explains why bowyers and clothiers will regularly produce foreign artifacts, while weaponsmiths will not.

== Success ==
Once created, most [[artifact]]s will be available for use just like a normal item of its type. Artifact [[armor]] and [[weapon]]s gain extra bonuses in combat, while artifact clothing is immune to [[wear]]. Artifact mechanisms installed in weapon traps will improve attack rolls. Artifact furniture is useful for raising the value of a [[noble]]'s room. Artifact mechanisms, trap components, or weapons in [[weapon trap|weapon trap]]s can also boost a room's value considerably. Other artifacts that can be used in construction (such as [[barrel]]s, [[bucket]]s, and [[anvil]]s) may be used similarly. Artifact [[door]]s and [[hatch]]es are immune to [[building destroyer]]s. Artifact crafts are currently useless, and artifact [[cage]]s should ''not'' be used to hold hostile creatures--due to a bug they can escape.

Successfully creating an artifact grants a very strong happy [[thought]] (enough to make the creator totally ecstatic for several months) as well as granting the creator partial '''immunity to insanity''' - even if your fortress enters a [[tantrum]] spiral, any dwarf who has created an artifact is exempt from going [[insane]] due to prolonged unhappiness.

== Failure ==
If you can't provide the desired workshop and all the required component materials within a couple of months, the dwarf will go [[insanity|insane]], which cancels the mood and the artifact. As if that's not bad enough, any dwarf who goes insane will soon die, one way or another.

A dwarf who is '''stark raving mad''' or '''melancholy''' is harmless to others (until they die and start a [[tantrum]] spiral), but a '''berserk''' dwarf will attack other dwarves and possibly pull levers at random. You may want to station a squad nearby or assign a few war dogs to the dwarf on the chance that they will lash out. If you build your workshops inside enclosed rooms with doors you can also lock the moody dwarf in the room until he or she starves. In extreme cases, building a wall around an open workshop is the best precaution.

==Bugs==
There are many bugs reported related to moody dwarves. As has been the case in 40d, most turned out to be (understandable) failures of the player to grasp the mechanics of artifact creation and demands. ([http://bay12games.com/dwarves/mantisbt/view_all_bug_page.php Bug tracker])
* Moody dwarves don't respect burrows when grabbing a workshop, but ''do'' when looking for items. {{bug|1416}} If a dwarf's claimed workshop is outside their assigned burrow, the dwarf will continue to grab materials until all materials of the needed type are exhausted within the assigned burrow. (See [[Main:Planepacked|Planepacked]]).
* If a dwarf dies due to failing to complete an artifact, a memorial made to the dwarf will read that the dwarf did create it, despite the failure, and will even list the name of the artifact that never came to be. {{bug|3640}}
* When producing an item that is normally made in pairs (gloves, boots, etc.), only a single artifact will be created.

== Troubleshooting ==

'''Problem''': Moody dwarf does not claim a workshop
:'''Solution''': Check for highest moodable skill and build the corresponding workshop. If no moodable skills, build a craftsdwarf's workshop. Once [[magma forge]]s have been built, some dwarves may demand to work at a magma forge. Note that [[forbid]]den workshops cannot be claimed.

'''Problem''': Moody dwarf waits in claimed workshop
:'''Solution''': Desired material is unavailable. Determine which material is requested next (materials are collected in the same order as shown in the dwarf's request list), and make some available, if possible. Note that dwarves with [[preference]]s may demand a specific type of material ([[brass]] bars or [[yarn]] cloth, for example). [[Forbid]]den and inaccessible materials cannot be collected, nor can material located outside the moody dwarf's [[burrow]].

'''Problem''': Moody dwarf collects base material continually
:'''Solution''': The claimed workshop is outside of the dwarf's [[burrow]], resulting in the [[Main:Planepacked|Planepacked]] glitch. Add the workshop to the burrow or remove the dwarf from the burrow to finish collecting materials.

'''Problem''': No dwarf has entered a mood for a long time
:'''Solution''': Strange moods require at least 20 dwarves; if you have that many you've probably hit one of the two caps. Exploring the caverns can increase the number of revealed tiles very quickly, while [[craft]]ing [[goblet]]s will quickly raise your item count; [[exploratory mining]] will count toward ''both'' caps, simultaneously revealing tiles and producing boulders, though slower than exploring or crafting. Exposing excavated terrain to the sky is counterproductive, as it will '''lower''' your artifact cap (since the cap only counts revealed ''subterranean'' tiles).

{{Category|Dwarves}}

Minecart

2015-06-21T03:46:02Z

NW Kohaku: /* Track Direction Irrelevance */ language clarification

{{Quality|Masterwork|08:15, 19 May 2015 (UTC)}}
{{av}}
A '''minecart''' is a [[tool]] intended for [[hauling]], introduced in version 0.34.08. It can be made of [[wood]] at a [[carpenter's workshop]] or [[metal]] at a [[metalsmith's forge]] (using the [[Metal crafter|metalcrafting]] labor.) Minecarts store up to five times as many items as [[wheelbarrow]]s and are quite a bit faster than dwarves hauling objects by hand, but have the disadvantages of requiring a dedicated track network, a complex route planning phase, and the possibility of dwarves [[Fun|blundering into the path of carts filled with lead ore]]. Tracks may be carved into stone, or [[Construction|constructed]]; the latter allows above-ground routes, but these are more difficult to set up due to their additional [[building material|material requirements]].

Just like wheelbarrows, minecarts are considered [[item]]s and are stored in a [[furniture]] [[stockpile]]. Despite their five-times-greater capacity, they are only 33% larger than wheelbarrows and are identical in base [[item value|value]] when made from the same [[material]] (the value may differ due to the [[item quality]]). [[thief|Thieves]] or even mischievous animals can steal minecarts, even when they are moving on a track{{cite forum|109460/3289070}}. However, minecarts moving fast enough or being ridden cannot be stolen.

Although most of the utility of minecarts is in [[fortress mode]], an [[adventure mode|adventurer]] can also ride in a minecart. Adventurers can also pick up and relocate minecarts.

The invention of minecarts revolutionized the [[minecart logic|Science of Dwarfputing]] by enabling smaller, faster logic systems to be built.

== Basic Minecart Usage ==
Minecarts can be used to swiftly transport dwarves, [[flow|fluids]], and/or large amounts of items, but before you have a functional minecart there are several preconditions that need to be met. First of all you need an actual minecart, constructed either in a [[carpenter's workshop]] or [[metalsmith's forge]]. For the minecart to be able to move you also need to carve (with {{k|d}} {{k|T}}) or construct (with {{k|b}} {{k|C}} {{k|T}}) a track, which could be as simple as a straight line. Finally you need to construct stops on your track (with {{k|b}} {{k|C}} {{k|S}}) where the minecart will start and stop.

After you have created the stops and assigned a cart to the track, you must create logic routes connecting several stops and designate starting conditions for each stop. This is done with the {{k|h}}auling key. The most basic conditions are how the cart's movement is initiated and in which direction the cart should start moving. Carts can be either be Pushed (a dwarf stands at a stop and gives the cart a single push) or Guided (a dwarf continually pushes the cart forward, guiding it along the track). The [[hauling]] [[labor]] required for pushing and guiding carts is called "Push/Haul Vehicles" and is turned on by default.

To control which items to transport you can add conditions specifying: (1) which kind of items to be loaded, and unloaded, (2) stockpile links to define which stockpile(s) the items should be un/loaded to and from.

===Capacity and weights ===
Minecarts have five times the [[Weight|capacity]] of [[wheelbarrow]]s.

'''Examples of the capacity of one cart'''
{| class="wikitable"
|-
! Item
! Amount
|-
| [[stone]]
| 5
|-
| [[wood|log]]
| 10
|-
| [[block]]/[[bar]]
| 83
|-
| [[Kitchen|prepared meals]]
| 500
|-
| [[Trap_component#Spiked_ball|spiked balls]]
| 500
|-
| [[Weapon#Native_weapons|mace]]
| 625
|-
| [[Weapon#Native_weapons|spears]]
| 1250
|-
| [[cloth]]
| 2500
|}

The weight of the loaded minecart does not affect the initial velocity received from pushing or launching from a roller. However, the load of a minecart ''does'' affect whether a [[pressure plate]] triggers or not, based on the pressure plate's setting.

'''Weights of different carts'''

{| class="wikitable"
|-
! Type of cart
! Empty cart
! Fully loaded (items)
|-
| oaken minecart
| 28Γ
| 378Γ (10 oak logs)
|-
| platinum minecart
| 856Γ
| 10482Γ (83 gold bars)
|}

The weight of a minecart is one twenty-fifth (1/25) the [[density]] of its material in Urists. Because pressure plates can be set to trigger at intervals of 50 Urists, minecarts with weights just under a multiple of 50 are ideal for switching based on whether they're full or empty. The best minecart materials for full/empty switching are as follows:

{| class="wikitable sortable"
|-
! Material !! Minecart weight !! Content weight required to trigger !! Banana roasts required to trigger (for scale)
|-
| [[Bismuth]] (moods only) || 391 || 9 || 15
|-
| [[Brass]] || 342 || 8 || 14
|-
| [[Electrum]] || 596 || 4 || 7
|-
| [[Fine pewter]] || 291 || 9 || 15
|-
| [[Glumprong]] || 48 || 2 || 4
|-
| [[Lay pewter]] || 291 || 9 || 15
|-
| [[Nickel silver]] || 346 || 4 || 7
|-
| [[Tin]] || 291 || 9 || 15
|-
| [[Trifle pewter]] || 291 || 9 || 15
|}

=== Creating tracks ===
Minecart tracks are made up of contiguous track, tracked ramp, or bridge tiles. Track tiles and tracked ramp tiles have a direction or series of directions associated with them. These directions dictate which directions a minecart on a given tile may move from that tile. For example, a Track NE (northeast) tile allows a minecart on it to move either north or east from its present position. Therefore, if you want your minecart to move east along a straight piece of track, then return west using that same track, you would need to use EW tracks so that the cart could travel east initially, then return west over the same track. Excluding designs in which the cart will "jump" tracks via a drop or other ramp, tracks must be valid end to end to work for most looped or straight-track applications. A single east only track tile in your line of east-west tracks will cause any route using the track to fail the moment it tries to go the wrong way over that tile. Minecart tracks can be built in two ways: Engraved/carved or constructed. A given minecart track need not use engraved or constructed elements exclusively, as the two methods can be used interchangeably depending on the needs of a given section of track. The way the tracks are built is slightly different between the two, as explained below.

====Simple tracks====

'''Carved'''

A single-tile wide strip of natural stone can be designated to be [[Engraver|carved]] (with {{K|d}} {{k|T}}), which will create a straight two-way track. The creation of corners, crossings, and T-junctions is as simple as designating another strip of track that overlaps an existent or newly designated track. Engraved tracks are removed by [[smoothing]] the rock they're on, which results in a smooth floor (that can be re-engraved if necessary), or by building a [[floor]] on top and subsequently removing it. Dwarves can carve corner tracks in one pass by designating the track carving twice and canceling unwanted carvings (with {{K|d}} {{K|x}}). Tracks can be engraved in any natural floor tile, rough, smooth and even over engravings, providing an easy method to remove low-quality or undesired floor engravings. Once a track has been engraved, it's important to check the track directions for each tile in the route carefully to make sure no mistakes were made by yourself or the game's track engraving logic.

'''Constructed'''

Tracks can also be built as regular [[construction]]s (through {{K|b}} {{K|C}} {{K|T}}). This method is resource-expensive, since each track tile requires one stone, [[bar]], or [[block]] for construction, and time-consuming, since you can't designate strips longer than 10 tiles at a time. Corners, crossings, T-junctions, and ramps also have to be designated individually. However, it is usually the only way to build tracks above ground or on soil (barring the [[Obsidian farming|creation of obsidian]]). Constructed tracks are designated for removal like any regular construction; be aware that removing track ramps built on top of natural ones will also remove the original ramp, leaving a flat floor.

====Ramps====

'''Carved'''

The carving of natural ramps is a little more confusing: to carve a two-way track on a ramp (natural only, does not work on constructed ramps), you must designate the track '''starting on the ramp and one square beyond''' in the direction you want the track to go. For the side of the ramp square you want to head upward, there '''must''' be either a natural or constructed wall in the square next to it, otherwise the game assumes you are trying to carve it on the same level -- this can result in the track being carved underneath a door or other object. If you have accidentally done this, you can correct it by smoothing the ramp and constructing a single square of wall next to it, then re-carving the ramp correctly. (However, the wall must stay there permanently; removing it will disconnect the track.)

'''Constructed'''

When constructing track ramps, the stated direction should be the same as the connected tracks. For example, a track going up from West to East would require, starting from the West, a Track (EW), a Track/Ramp (EW) and a Wall behind the ramp, underneath the section of track above it. Incorrectly placed ramps result in minecarts ignoring the ramp and crashing into the supporting wall. They will not, however, display as unusable as when the supporting wall is missing.

'''Examples of ramps'''

A simple ramp would look like this:
{{diagram|spaces=yes|\
z +0 z +1
░░░░ ░░░░
═▲o ░▼═
░░░░ ░░░░
o : wall
}}

Carving track corners into ramps is rather unintuitive and complicated. Since engraving tracks always requires two tiles to connect in a straight line as input, you have to give two separate designations for a single job: a track bit from the ramp tile to the "below" direction and another one to the wall of the "upward" direction. If you wanted to change direction on a ramp from east to north:
{{diagram|spaces=yes|\
z +0 z +1
░░░░░ ░░░░░
░░░░░ ══╗░░
=▲░░ ░░▼░░
░░░░░ ░░░░░
}}
you would need to connect the ramp on z +0 both to the west and to the north by issuing two "carve track" commands, one selecting the ramp and the track tile to the west, and another connecting the ramp tile with the wall to the north. An engraver would then carve a NW track corner into the ramp, allowing carts to pass the corner correctly both going up and down. Such track corners are perfectly serviceable for guided carts, but moving down a route of several of them by pushed or ridden cart is problematic - ramps on corners behave very counter-intuitively, resulting in loss of speed when going down and diagonal movement when going up.

Moving to and from ramps (or between ramps "pointing" in different directions0 causes some non-trivial adjustments to speed and even moving along the tiles at a fixed speed ''unrelated to the entry/exit velocity values'', because transitions to/from ramps are processed differently and are not to be "skipped". This affects compact track/ramp combinations (such as e.g. a simple 2x2 ramp spiral) most, and combined with bouncing often makes them work not in the way one could expect. {{cite forum|144328/5705102}}

{{anchor|Tracks}}

=== Hauling route ===
A hauling route is a list of directions describing how and under what conditions a minecart will move. The proper setting up of routes is essential for a working rail system. Routes, stops, departure conditions and stockpile links are managed from the {{k|h}}auling menu.

==== Route ====
A route defines the path a minecart will take along a track, as well as under what conditions it will move or stop moving. A route is made up of stops. Stops are precisely what they sound like, a position on the track at which you want a minecart to stop. A minecart track might use as little as a single stop for a looped track, which will serve as both a starting and stopping point for the cart, or it could contain many stops, perhaps to load supplies or wait for a bridge to be manually lowered, before reaching its destination or returning to its starting point. It is important to note that you only need to place stops on a route where you actually want the cart to stop and wait for some action to occur. They are not needed to help navigate the cart along the track beyond telling it where on the track to stop.

New routes are created with the {{k|h}}auling key. Existing ones can be removed (without confirmation) with the {{k|x}} key, and also {{k|n}}icknamed. Before operating, the route must have a {{k|v}}ehicle assigned to it (this can be done with either the route or a stop selected). Assigning a full minecart to a route may result in a slow hauling job if the contents are heavy.

==== Stops ====
Stops are the individual waypoints that make up a hauling route. A given stop consists of the location of a tile, as well as conditions describing when, where, and how a cart should be moved after being stopped at that tile. Stops can be created from within the {{k|h}}auling menu, by placing the cursor over a tile and hitting {{k|s}} while highlighting the route (or a stop within) you've already designated. A minecart will begin its route at the first stop created, and continue through each subsequent stop, being guided, pushed, or ridden from each stop to the next depending on the conditions specified. In many basic minecart applications, the cart will end up at the same stop it began at, though this is not always the case. It is important to note that hauling stop order is enforced, even if there is no track. A dwarf will drag the cart overland back to a skipped stop in the route's list if your tracks bypass it somehow.

Once a stop has been placed, it is given a default set of conditions under which to move the minecart if it is stopped there. Each new stop gets the same default conditions regardless of the track it is placed upon (e.g. guide the cart to the north). For this reason new stops might get marked by yellow exclamation marks ({{DFtext|!|#ff0}}) due to invalid directions. One important thing to note is that as you place additional stops, the display will show paths between the stops you have defined. However, this is '''not''' necessarily the actual route the minecart will take once the route is in operation. For example, if a route were defined with two stops at opposite ends of a track with many twists and turns, a line will be drawn directly between those stops to show the order in which they will be visited. These route lines may crisscross all over the tracks, but so long as the track is valid end to end, the cart will follow the track from one stop to the next, even across twists, turns, and z-level changes. Stops, which are the steps that make up a route, should not be confused with Track Stops, described below.

===== Stockpile links =====
By placing the cursor on top of a stockpile and using {{k|s}}, you can create stockpile links while defining a hauling stop. Links can also be redefined by selecting them, placing the cursor over a different stockpile, and pressing {{k|p}}. The cart will then be filled by items present in its various linked stockpiles in preference to other items. Note that bins should be used with caution in stockpiles that are linked to minecarts. Bins cause problems when used with the "Desired Items" list in a stop's conditions. For example, if a minecart is set to accept only granite blocks, and to depart north when it is 100% full of granite blocks, it will not depart if any of those granite blocks are in bins, even if bins are also included in the desired items list. Two solutions to this problem exist as of v0.40.24. First, bins can be disallowed in stockpiles that are linked to stops. Alternatively, bins '''can''' be used in conjunction with minecarts provided that the minecart's departure conditions use only "any items" instead of "desired items." This option can be toggled in the advanced conditions menu for a stop, accessible via the {{key|C|}} key. The cart's contents can still be controlled by specifying what items are allowed in the linked stockpile.

===== Departure condition =====
Departure conditions involve setting conditions in which the minecart will leave on the route. Each condition includes:
# A departure mode (Guide, Ride or Push).
# An initial departure direction (NSEW). Note that this defines the initial direction of movement only. Even if a track includes many turns, as long as the initial movement direction is valid the cart will follow the minecart track thereafter.
# A timer, before which the departure condition cannot be met.
# Conditions on the amount of items in the cart.
Departure conditions are created with the {{k|n}} key. A new departure condition will read: "guide north immediately when empty of desired items". This condition can be changed between basic presets with {{k|c}}. "Advanced" mode ({{k|C}}) allows for more precise control over departure conditions: fine tuning the percentage from 0 to 100 in 25% steps ({{k|f}} and {{k|F}}), switching it being either the maximum or the minimum amount of items for the condition to be met ({{k|m}}), and whether the cart accepts all or only a specific set of items ({{k|l}}). Common to both screens are the departure mode ({{k|p}}, Push, Ride or Guide), {{k|d}}irection, and timer ({{k|t}} and {{k|T}}) options.

To have a cart only carry a specific set of items, the stop can be set to only carry "desired" items, opening the selection screen with the {{k|Enter}} key while having said stop condition selected, and toggling as desired, or it can simply be linked to a stockpile and set to depart once it is full of items from its linked stockpiles, regardless of type.

=== Track Stops ===
A Track Stop, not to be confused with a route stop, is an optional, single-tile construction which serves two purposes. First, it can be used to cancel a cart's momentum in order to slow or stop it as it passes over the Track Stop. This might be necessary if a cart were pushed down a series of ramps to its destination. Second, a Track Stop can cause a cart to automatically dump its contents as it passes over the Track Stop. Track Stops are constructed via {{k|b}} {{k|C}} {{k|S}}, and must be constructed atop an existing piece of track. If a Track Stop has been set to automatically dump a cart's contents, the cart will dump its contents in the direction indicated when it passes over the Track Stop. Depending on the friction settings chosen for the Track Stop, the cart might then stop after dumping, or it might continue on its route to another destination.

Track Stops are not mandatory; in fact, their main use is in automated rail systems. However, even in basic rail systems it can be useful to set a Track Stop to dump items: this saves time that dwarves would otherwise spend in removing items from the cart, time that is better spent driving the cart back to where it's needed. Dumping will occur even with a guided cart. '''Take care not to set Track Stops at a loading site to dump their contents''', or dwarves will never be able to fill the cart. It will dump any contents the moment they are loaded.

Counter-intuitive to their construction method, Track Stops are considered [[building]]s and must be removed by {{k|q}} {{k|x}}.
* See [[#More_on_Track_stop |More on Track Stops]]

=== Step-by-step tutorial ===

Let's construct a simple minecart route. This route will move stone blocks from an input stockpile to an output stockpile. We'll begin by creating the stockpiles:

[[File:minecart-example-1.png|Stockpiles designated.]]

The input stockpile is on the left; the output stockpile is on the right. We'll be moving blocks from left to right. Disable bins in both stockpiles, and set the input stockpile to accept only from links. Then make the stockpile take from the mason's workshop where the blocks are being produced.

Next, carve the track:

[[File:minecart-example-2.png|Track carving designation.]]

Note that the ends of the designation are uniquely shaped; this is automatic, and not anything you need to control. Now, wait for your engravers to come along and carve the track into the stone. (Your haulers will probably also fill up the input stockpile while you wait.)

In addition, while we're waiting for that to happen, we'll build an iron minecart in the forge.

[[File:minecart-example-3.png|Track carved.]]

When the track has been carved, it will look like the above (the track will be solid instead of flashing). Now, order a track stop to be constructed next to the output stockpile:

{|
| [[File:minecart-example-4.png|Track stop designation.]]
| [[File:minecart-example-5.png|Select dumping direction.]]
|}

You must press {{k|d}} three times to select the dumping direction ''before'' placing the track stop. We want our blocks to be dumped into the output stockpile east of the track stop. Then wait for a mechanic to come along and build the track stop.

[[File:minecart-example-6.png|Track stop constructed.]]

Now we'll define the actual ''route''. This is done in the {{k|h}}auling menu. Press {{k|r}} to begin defining a route. Next, move the cursor to the input end of the track, and then press {{k|s}} to define the first stop:

{|
| [[File:minecart-example-7.png|Stop 1 designation.]]
| [[File:minecart-example-8.png|Route definition, in progress.]]
|}

Move the cursor again, to the output end of the track, and press {{k|s}} again to define the second stop:

{|
| [[File:minecart-example-9.png|Stop 2 designation.]]
| [[File:minecart-example-10.png|Route definition, two stops.]]
|-
|
| [[File:minecart-example-11.png|Stops are not defined yet.]]
|}

There are several user interface features to note at this point. The stops have been positioned, but they haven't been ''defined'' yet, so there is a warning {{DFtext|!|#ff0}} symbol by each of them. In the lower right corner, we see what the {{DFtext|!|#ff0}} means. Also, note that the second stop is labeled in white, while the other two lines are grey. The white text is a selection indicator, and can be moved up and down by pressing {{k|+}}/{{k|-}}.

Next we need to define what our stops do. We want the minecart to be filled with blocks at the first stop, then travel to the second stop where it will dump its cargo, and then return. Press {{k|-}} to move the selection up to stop 1, and {{k|Enter}} to open it up. By default, the stop has three conditions:

[[File:minecart-example-12.png|Default stop definition.]]

We don't want any of these, so press {{k|x}} three times to delete them. This leaves us with a blank stop. Now we can add the conditions we actually want. Press {{k|n}} to begin adding the first condition, then {{k|d}} twice to change the direction from north to east. Then press {{k|c}} to change the condition from empty to full. This will instruct the minecart to be guided east when full of desired items.

To set the desired items, we create a stockpile link. Press {{k|s}}, then move the cursor to the input stockpile, then press {{k|p}} to select that stockpile. Now press {{k|Enter}}; this opens up a selection screen that resembles the stockpile customization screen. Move down to Blocks, {{k|e}}nable them, then (if you wish) restrict it to stone blocks.

When you've done all that, stop 1 should look like this:

[[File:minecart-example-13.png|Stop 1, defined.]]

Stop 2 is much simpler. All we need to do is have the minecart return to the input stop. So, make a condition and change the direction:

[[File:minecart-example-14.png|Stop 2, defined.]]

Finally, we just have to assign our minecart. Go back to the route definition screen, and press {{k|v}}. Select the minecart, and press {{k|Enter}}.

Now we've got everything set up:

[[File:minecart-example-15.png|Route, fully defined.]]

The V is red because the minecart hasn't been moved onto the track yet. Some dwarf will have to haul it from the forge to the first stop, by hand; this will take a while, especially if the forge is far away.

Once the minecart is in place, dwarves should fill it with blocks from the input stockpile, which will in turn be filled with blocks from the workshop where your mason has been toiling dutifully. When the minecart is full, the blocks will be dumped into the 1x1 stockpile on the right. Automatic quantum dumping!

=== Troubleshooting ===

Because of the complexity of the system, all but the most careful and experienced minecart users will encounter issues. Most route issues can be diagnosed and fixed from the {{k|h}}auling menu.

'''Symptom:''' {{DFtext|! Set dir/connect track|6:1}} message appears to the right of one or more stops

'''Possible Causes:'''
* The departure direction of the stop might be invalid. Edit the stop using {{k|Enter}} and press{{k|d}} until it is pointing in a valid direction.
* The track stop might not be built on top of a track. The track stop must be deconstructed to remedy this issue.
* Your track might not be built correctly. Make sure all connected tracks between destinations are not one-way tracks.
** This can be especially confusing with ramps. To carve a two-way track on a (natural) ramp, you must designate the ramp and one square beyond in the direction you want the track to go.
** Ramps '''must''' have a solid block on the side opposite to the track, or they will neither work nor be marked as "unusable". The solid block can be natural or constructed.
* The desired/kept items might not be configured correctly.

'''Symptom:''' The status '''0% V''' always appears to the right of one stop.

'''Possible Causes:'''
* The stop may not be set to take from a stockpile. Edit the Stop using {{k|Enter}} and make sure you see a message like "Take from Stockpile #1".
* The take conditions must correspond with the contents of the stockpile.
* The track stop may be set to dump. A track stop set to dump cannot be filled. You must either set the stop to a time-based departure or deconstruct the track stop and rebuild it without dumping. (Alternatively, with [[DFHack]] you can modify "Dump on arrival" to "No" using the {{key|q}} menu without rebuilding the stop.)
* Make sure the minecart itself has not been designated to be dumped (such as when using mass-dump).

'''Symptom:''' Dwarves fill the minecart properly, but will not move it thereafter.

'''Possible Causes:'''
* The minecart may contain items which are not included in its current stop's desired items. Check inside the minecart using the {{key|k}} and {{key|z}} keys and ensure that all items in the cart are desired items.
* The minecart may contain desired items in bins. Minecarts seem to have problems realizing that they are in fact full of desired items if some of those items are in bins, even if bins are also among the desired items for that stop. '''This cannot be solved by adding the appropriate bins to the stop's desired items.''' Either disallow bins in stockpiles you intend to load minecarts from, or set the departure conditions to rely only on percentage of total load rather than percentage of desired items using the advanced conditions menu ({{key|C}} key).

'''Symptom:''' Dwarves repeatedly attempt to load the minecart, but no items are ever loaded into it.

'''Possible Causes:'''
* This can be caused by using a Track Stop with autodumping enabled at a loading site. Every time a dwarf places an item into a cart resting on such a track stop, the item will be immediately dumped, causing unlimited, useless cart loading jobs. Autodumping Track Stops should never be used at a loading site.

'''Symptom:''' A dwarf picks up the minecart and carries it to its destination.
* See [[#Quirks|Quirks]]

=== Danger ===
Minecarts are not without <strike>danger</strike> [[fun]]. Although designating a track automatically sets the [[traffic]] designation to low, dwarves ''may'' still walk on them, and [[creature]]s ignore traffic designations altogether. If an unlucky dwarf or creature fails to [[dodger|dodge]] a minecart, they can be injured. Most of this danger can be avoided by setting the minecart {{k|h}}auling commands to guide instead of push or ride (dwarves guiding minecarts will ignore traffic restrictions), as well as by [[pasture|pasturing]] domestic animals and preventing the access of other creatures to the tracks. Note that removing the track doesn't reset that tile back to normal traffic priority, so you may wish to manually clean up traffic designation afterward. Also note that bridges that are used as tracks don't have their traffic priority changed automatically (since they're just normal bridges), which could cause dwarves to pathfind normally through dangerous minecart entrances in your fort's walls if you're not careful.

The only <s>fool</s>''dwarf''-proof method is to make the tracks inaccessible. There are several ways to create a track which works for minecarts but doesn't allow creature-traversal; the simplest is perhaps building a [[statue]] on the tracks. Other options include adding single-tile holes (minecarts moving at reasonable speed will jump the gap), vertical drops, minecart-triggered doors, small pools of liquid (4/7 water or 2/7 magma), and hostile creatures overlooking the tracks. For safety, both ends of the track should be isolated, making the dangerous center sections completely inaccessible (though maintenance access can be provided by a locked door).

Danger does not always involve living victims: careless route designation can also result in minecarts careening off tracks or colliding with each other. If this occurs, the [[item]]s may be scattered; this can cause even more hauling jobs than the minecart aimed to eliminate. Even <s>better</s> worse, scattered items, especially [[weapon]]s, can injure passing [[dwarf|dwarves]] or other [[creature]]s; in the words of Toady One the Great, "Accidental grapeshotting of the dining room should be possible now."

Of course, the danger of using minecarts means they can also be [[Trap_design#Minecarts|used as weapons]] by imaginative players.

== Advanced usage and automation ==
Minecart-specific effects are implemented via track stops, rollers and [[pressure plate]]s with "track" condition set. Since all three are considered [[building]]s, they can't be built on the same square (however convenient track stop + pressure plate would be) nor a simple ramp, and are removed by {{k|q}} {{k|x}}.

=== More on Track stop ===
Track stops are constructions that allow further automation of minecart systems via adjustable features such as braking by friction and automatic dumping of contents. They can be built from logs, bars and blocks through {{K|b}} {{K|C}} {{K|S}}; friction amount, dumping toggle and dumping direction must be set '''before''' construction, and these settings can be neither changed nor seen thereafter; however, track stops can be linked to [[pressure plate]]s or [[lever]]s to toggle friction and dumping On or Off (trigger state is inverted: switch On = track stop Off).

If a [[stockpile]] is placed on the tile that a track stop is set to dump to, it can act as a [[Exploit#Quantum_stockpiles|quantum stockpile]] and any items dumped from a minecart that match the storage settings of the stockpile will remain there and accumulate. Normally trackstops are built on top of existing track to operate on moving minecarts, but they can also be used without tracks to create [[Exploit#The_Minecart_Stop|automatic quantum stockpiles]] (see also [[#Step-by-step_tutorial|step-by-step tutorial]]). It is not always desirable to collect ALL of certain items into one quantum stockpile, such as when distributing a material to multiple separate industries. You can link your quantum stockpile to various other stockpiles, ensuring that your dwarves will keep them supplied as necessary. Because quantum stockpiles never fill up like regular stockpiles, it may be a good idea to add a switch to turn them off.

Items dumped from a minecart at a track stop (or dumped by any other means) into open space fall through z-levels until they land on a solid surface. Items falling onto a designated [[stockpile]] will automatically be considered part of that stockpile, even if the stockpile is set to disallow those items (they will, however, be automatically moved to a more appropriate stockpile, if available). Items falling on top of a minecart will '''not''' fall "inside" the minecart. Use with caution; dwarves have fragile skulls.{{bug|5945}}

=== Automated propulsion ===
==== Roller ====
{{Main|Roller}}

A '''roller''' is a [[power]]ed [[machine component]] for the automated propulsion of minecarts. They are built over the top of existing tracks with {{K|b|M|r}}, requiring a [[mechanic]], ''(length/4)+1'' [[mechanism]]s and a [[rope]]. Rollers may also be placed directly on ramps to help pull carts up Z levels. Rollers are very useful to maintain a cart's momentum along long routes, to get them to climb Z-levels without dwarfpower involved, and to get them to reach speeds unattainable by guiding dwarves. These devices are variable-length (1-10), variable-direction and variable-speed ([[Minecart#Numbers_behind_the_scene|see below]]), all traits that can be set at construction time; a roller uses two units of power per tile it is long.

Single-tile rollers transfer power in all four cardinal directions, while other rollers generally only transfer power perpendicular to their activity direction. Longer rollers can also transfer power along their activity direction if built in the correct order, although this can be hard to accomplish and is easily broken. Rollers cannot be powered from above.

Rollers have great acceleration and capped speed. Carts going faster than the roller are unaffected. If a cart moves across an active roller in the direction the roller works and moves slower than the roller's specified speed, the cart will be set to the roller's speed. A cart going against a roller's movement direction will be sent back the way it came (once again at the roller's speed), unless it was moving extremely fast: speed increment of 100000 allows to reverse carts from the full "highest" (50000) speed roller to full "highest" speed back, but ramps can accelerate a cart beyond this. {{cite forum|144328/5702453}}
A cart crossing over a roller perpendicular to its current movement direction will gain the roller's amount of speed in the perpendicular direction without directly changing its forward motion. Without an adjacent wall to constrict its movement, this will typically send a cart off the rails on a diagonal path, completely unable to follow any tracks until it collides with a wall or is otherwise brought to rest. However, if the roller is placed over a track turn and pushes ''from'' the direction of that turn's track, the turn affects carts ''after'' the roller, so they will be forced into the turn rather than derailed in a diagonal direction. {{cite forum|144328/5702453}}

{{diagram|spaces=yes|\
tracks: full:
║ ║
═╗═ ═╢═
║ ║

╢ : roller pushing from W to E
}}
If the roller is powered, carts from ''all'' directions (unless too fast) exit S, because speed imparted by the roller forces carts toward E and ''then'' into the turn.
If not powered, carts from W and N exit S, carts from E and S exit W. Carts above derail speed will ignore the turn, of course.

{{diagram|spaces=yes|\
║ ║
═╗═ ═╟═
║ ║

╟ : Roller pushing from E to W
}}
Carts from the E or W: exit W.
Carts from N: derailed diagonally, exit SW.
Carts from S: derailed diagonally, exit NW.

Rollers affects carts on a track - if placed on a floor or ramp without any tracks, they are ignored. Depowered rollers are also ignored, friction is determined by the tiles underneath.

Because of their one-way nature, rollers are unsuitable for most two-way minecart tracks (unless you set gears toggling roller A->B off while toggling A<-B rollers on). However, a minecart set to be ''guided'' is not affected by rollers at all{{cite forum|109460/3286235}} — this allows a one-way track to be used in both directions. In addition, unpowered rollers do not affect minecarts.

Care must be taken in [[glacier]]s and other extremely cold [[biome]]s, since rollers (and the machinery used to power them) will not operate when constructed on natural [[ice]] floors.

==== Impulse ramps ====
Carts can be given momentum without rollers or changing z-level through a phenomenon called "impulse ramps". A track ramp which is connected both to a wall and to a floor will ''always'' accelerate a cart towards the connected floor tile, no matter where the cart enters the tile from. This means carts can be accelerated as though dropping z-levels, even if the cart doesn't actually change z-level at all. If a track ramp faces three directions such as ╩, then two of those directions need to be facing walls for the cart to be accelerated towards the remaining direction.

Example of straight impulse acceleration:

{{diagram|spaces=yes|\
▒▒▒▒▒▒▒▒▒▒ ▒▒▒▒▒▒▒▒▒▒
═▲▲▲▲▲▲▲▲▲▲═ ═╚╚╚╚╚╚╚╚╚╚═
▒ : Wall
═ : Normal track
▲/╚ : N/E Track/Ramp
}}

If a cart enters from the left, it will speed up on every track/ramp and exit to the right going very very fast - more than one tile every step. If it enters from the right then it will bounce back impulsed by the ramp if it's going slow enough.

As another oddity, carts coming from ramps will in some cases "teleport" through most of the next tile. This is called the "checkpoint effect", and is explained in detail in the Physics section, below. This negates the deceleration of the next tile if it is a ramp "angled" in a different direction. You can just make an upward spiral alternating impulse ramps and regular upward ramps. It takes no power, is quick and cheap to build, requiring only channeling and track carving, and the cart goes up fast, but not so fast that it launches its contents.

Example of an impulse elevator:

{{diagram|spaces=yes|\
z +0 z +1 z +2 z +3
░░░░░ ░░░░░ ░░░░░ ░░░░░
░╔░░░ ░▼╚╗░ ░░▼▼░ ░░░░░
░╝░░░ ░▼░░░ ░░░╔░ ░░░▼░
░▼▼░░ ░░░░░ ░░░╝░ ░╚╗▼░
░░░░░ ░░░░░ ░░░░░ ░░░░░

░ : Wall
╔,╚,╗,╝ : Track/Ramp
▼ : Down Ramp (empty space)
}}

Note that this impulse elevator, due to the checkpoint effect and upward curved ramp effect, will not actually result in carts traveling straight up the ramp. They will lose speed, bounce off a ramp, then be accelerated back into the spiral after a 9-turn delay on both tiles on the floor where they are stopped. This is because the checkpoint effect allows carts to travel up the ramps in a single turn, but also prevents the impulse ramps from adding acceleration unless the cart is slowed to staying on the ramp for more than one turn. Initial acceleration will carry the cart up a variable number of floors before this effect occurs, but this bouncing back and forth will occur every 5 z-levels after the first time the cart stops. When the cart ''is'' traveling upwards, it will pass every tile at a rate of one tile per turn regardless of its actual speed, due to the checkpoint effect. In tracks with only a single cart, this is negligible, but when multiple carts are on the same track (such as when you place multiple carts on a magma cart lift) this can cause collisions which derail carts or cause other unexpected or undesired behaviors.

The following impulse ramp (while larger) should alleviate these problems by using a straight ramp to go upwards, preceded by an impulse ramp to exploit the checkpoint effect and negate up ramp costs. Corners still decelerate carts, so the cart will tend towards a velocity of 72k, which is derail speed. Derail speed breaks (see Controlling Speed, below) may be necessary at the top.

{{diagram|spaces=yes|\
z +0 z +1 z +2 z +3
░░░░░░ ░░░░░░ ░░░░░░ ░░░░░░
░░░░░░ ░╔╔═░░ ░░▼▼╗░ ░░░░░░
░║░░░░ ░▼░░░░ ░░░░╗░ ░░░░▼░
░╚░░░░ ░▼░░░░ ░░░░║░ ░░░░▼░
░╚▼▼░░ ░░░░░░ ░░░░░░ ░░═╝╝░
░░░░░░ ░░░░░░ ░░░░░░ ░░░░░░

░ : Wall
║,═,╔,╚,╗,╝ : Track/Ramp
▼ : Down Ramp (empty space)
}}

Also, if you want to have a cart following a below-derail speed, the following track works well:
{{diagram|spaces=yes|\
z +0 z +1 z +2 z +3
░░░░░ ░░░░░ ░░░░░ ░░░░░
░░░░░ ░══░░ ░▼▼║░ ░░░▼░
░║░░░ ░▼░░░ ░░░║░ ░░░▼░
░║▼▼░ ░▼░░░ ░░░░░ ░░══░
░░░░░ ░░░░░ ░░░░░ ░░░░░

░ : Wall
║,═ : Track/Ramp
▼ : Down Ramp (empty space)
}}
In this elevator, the cart collides with the walls in the corners, but then realigns on the ramp, picks up speed, checkpoints through the next ramp, and slams into the next wall. It is slower (10 ticks per floor) but produces reliable speeds, and will exit the impulse elevator at little more than push speeds.

A sort of opposite effect to impulse ramps also exists: ramps lacking the proper "up" and "down" connections are treated as flat track, even if they actually go up or down z-levels. This allows building "anti-impulse" slopes consisting entirely of ramps only connected up, which a minecart can travel up forty levels and more, needing no more than a single push.

=== Controlling traffic ===

==== Switching ====

As constructions or tile features, [[door]]s and other furniture can be built on tracks. A [[door]] or [[floodgate]] can be turned on or off by a [[lever]], effectively controlling the flow of automated minecarts. This may be <s>dangerous</s> [[fun]], however.
{{diagram|spaces=yes|\
->
A ════┤≡════ B
┤ : roller pushing to East
≡ : door
}}
The roller pushes the cart east, but until the "departure condition" is fulfilled, the door remains closed and blocks the path.

[[Bridge]]s can also act as tracks, but only if they're lowered or not retracted. This property can enable levers to turn tracks on and off. However, care should be taken to ensure that such bridges are never operated while a cart is on top of them, as the cart will be flung off the track. It's worth noting that it's often faster, and cheaper, to construct large bridges than long sections of constructed track.

A powered track switch can be constructed by building an "inverted" corner as illustrated below.
{{diagram|spaces=yes|\
B B
║ -> ║
║ ║
════╚═══ ════├════
A C A C
├ : roller pushing to West.
}}

If the cart is pushed East from the stop at 'A' while the roller is activated, it will arrive at 'B'. If the roller is not running, it will arrive at 'C'. The switch works by the roller first reversing the incoming cart's movement and the cart ''then'' following the track corner.

This switch is very reliable, reacts instantly to on/off signals, and carts of any speed can be switched by this design, although very fast carts will require rollers that are several tiles long, up to three. The requirement for power can be inconvenient or impractical. Non-powered solutions may use controlled derailment, or a connecting bridge.
{{diagram|spaces=yes|\
B ╥
║
║
╞════╝ ════╡
A D C
}}
Here the track between A and C is not continuous. The only continuous track is A->B, with a corner (not a T section). Fast moving carts will tend to derail at D and rejoin the track to C. Placing a door at D will prevent the derailment, so the cart continues to B. The door is operated by mechanisms elsewhere (typically, a lever, but some fun can be had with pressure plates).

Since it depends on derailing, this switch requires a very fast cart, faster than what can be achieved with rollers alone. To gain sufficient speed, a cart must be accelerated further, usually by descending several levels or through impulse ramps. The high speed makes the cart much more dangerous and harder to control.

If carts are moving too slowly to derail at the corner, a retractable bridge may be used as a connector between A and C.
{{diagram|spaces=yes|\
B╥
║
║
A╞════bbb════╡C
}}
The bridge must overlap the corner. Bridges behave like a track crossing, allowing carts to pass in a straight line. When retracted, the corner reappears, so the carts will continue to B. Bridges take 100 steps to react to a signal, necessitating rather long "lead times" when switching tracks via bridge.

As mentioned above, special care must be taken to make sure the bridge doesn't change state while the cart is passing over it. Retracting bridges will throw the cart, causing it to stop dead. Raising bridges can even crush the cart.

==== Controlling Speed ====


Minecarts can reach extremely high speeds, especially when descending multiple Z-levels. A minecart will derail at a track corner if its speed exceeds 0.5 t/st (tiles per step), '''unless''' the route in the direction of travel is blocked:

Will derail at > 0.5 t/st:

{{diagram|spaces=yes|\
in ══╗ -> derailing
║
out
}}

Will not derail at > 0.5 t/st:
{{diagram|spaces=yes|\
in ══╗O
║
out

O : wall/column.
}}

This behavior can be used to build a "speed limiter", that will ensure that when a minecart exits it is traveling below derail speed:
{{diagram|spaces=yes|\
░░░░ ░░░░░ ░░░░░
in ═╔═╗░ ░╔S╗░ ░╔S╗░
out ═╬═╝░ out ═╗═╝░ out ═╗═╝░
░╚S╝░ ░╚═╝═ in ░╚S╝░
░░░░░ ░░░░ ║░░░
in
░ : wall
S : Track Stop (High Friction or lower)
}}
If the minecart is traveling below derailment speed, it will not be affected; if above, will be slowed down and checked again. Granted, you could do the same just with track turns, but it may take a lot of turns and time.

Since all the derailings, bounces and ramps can impart a sideway component of speed small enough to start visible drift many tiles away (say, [[Fun|in the middle of a bridge]]), track turns have one more use: forcing the carts to move strictly along the grid directions. Carts passing a turn below derailing speed convert one component of velocity into another, thus eliminating the drift.

=== Loading liquids ===
[[Water]] and [[magma]] can also be loaded into minecarts by submerging them to a depth of at least 6/7 while standing still or moving at speeds of at most 10000. Loading fluids onto minecarts can be difficult because the added friction provided by fluids can stop a cart in a submerged tile. Curiously, filling a minecart with magma does not injure a dwarf ''riding'' it. A minecart will hold enough fluid to increase the depth of a single tile by 2. This amount is listed as 833 units, which weigh 459Γ (water) or 999Γ (magma). An iron or steel cart filled with magma weighs 1313Γ, while an adamantine cart filled with magma weighs 1007Γ. Since you need a minecart above the liquid's level, possible arrangements may include pressure-activated sluices, rollers (with magma-safe chains for magma), pouring from above to "submerge" it briefly on the same level and drain excess away (dig deeper and leave a vaporizer, though if you could have power for rollers, may as well use a pump) and exploits with ramps (not necessarily impulse ramps, "same height" passing dip does it).
The liquids can be dumped by a constructed track stop.

== Quirks ==
This little quirk concerns dwarf-managed minecarts. If a track which was previously open becomes blocked (ex. flipping a switch connected to a floodgate you've built on the track to raise it) and the conditions for departure are met, instead of refusing to ride/guide the minecart or ride/guide it until it reaches the obstacle, the dwarf will pick up the minecart off the tracks and haul it to its scheduled destination on foot. If the distance is long enough and the weight of the cart heavy enough (due to being filled with heavy items such as stones), the dwarf may drop the cart because of fatigue/hunger/thirst before reaching the destination. This will cancel that vehicle setting job and make another dwarf come by and attempt to haul the cart to the nearest appropriate stockpile where another dwarf will pick up the cart and attempt to haul it to its initial stop. If the stockpile is far enough from initial stop, this second dwarf who is attempting to place the minecart on its tracks may also drop the minecart out of fatigue/hunger/thirst creating a loop that will go on until a dwarf with enough endurance manages to place the minecart where it belongs.

In fact, it seems dwarves are more than happy to attempt to carry a minecart from one stop to another even if just waiting until the track is open again would be the more sane option.

Dwarves will also carry a minecart to its next stop if the direction specified is incorrect (or invalid). This can often occur when using the default departure settings and forgetting to set the direction of each condition.

Dwarves can admire buildings while riding mine carts. Dwarves will not fall asleep during a ride (at least not from being drowsy). If riding on a continuous powered track loop, the dwarf will die of dehydration/starvation as they can not jump off to get sustenance{{cite forum|109460/3377228}}. Dwarves riding in submerged minecarts will gain experience in [[swimming]].{{cite forum|129889}}

Tracks block wagon access to trade depots, unless they're on a ramp. [[Bridge]]s can also be used, as they function as tracks but do not block wagons.

== Physics ==


Minecart physics depend greatly on the departure mode set in the route stop conditions.

When set to "Push" or "Ride", minecarts will move according to the regular laws of momentum, gaining speed when going downhill, losing it slowly due to friction when on a flat plane, and more quickly when going uphill. In these modes, minecarts will move in a straight line until they either are brought to a stop by friction or an obstacle, or until they encounter a turn. A minecart will roll straight past "blocked" ends of T-junctions or track ends, they have no power to restrict a cart's movement. The cart's behavior is largely independent of the weight of its contents (including fluids and dwarves): heavily loaded carts gain more momentum when accelerating, but this only plays a role in collisions: a heavy cart gains just as much speed and is as easy to stop as a light one. In either case, dwarves can not push nor ride an unpowered cart up a ramp, bouncing back the direction it came. At best, this is a waste of time; at worst, it will give your cart-pushing dwarf a [[fun|fun surprise]]. To solve this, the player can either use Rollers (see below) or set the cart to be Guided.

The difference between "Push" and "Ride" is whether the dwarf will go along with the cart or not.
{{DFtext|Push}}: the dwarf will give the cart an initial push, not enough to go up a ramp, but enough to go some way along flat track, and the dwarf will remain at the first stop, ready for a new job.
{{DFtext|Ride}}: the dwarf will give the cart the same initial push and then hop aboard the cart riding with it to the next stop.
{{DFtext|Guide}}: minecarts seem to ignore all laws of physics. That is:
*Ignore the weight of any and all items inside. Therefore:
**Move at the speed of the dwarf that is guiding them. It is thus recommended to pick the most [[attribute#Agility|agile]] of your dwarves for cart-guiding tasks.
*Ignore working rollers.
*Will ''not'' collide with other guided carts even when a full frontal collision would be expected.
*Will go up ramps like nobody's business.
This is therefore the recommended method of transport for simple non-powered rail systems, despite it diverting a dwarf from other, potentially more important tasks.

Some samples with behavior:
{{diagram|spaces=yes|\
A <-> B A <-> C A <-> B
B B B
║ ║ ║
A══╝ A══╩══C A══╬╗
You can only go A->B ╚╝
Works when the cart Works
is in Guide mode.
}}
In the second example above, a cart "pushed" from B will go over the junction and roll off into the unknown south.

=== Numbers behind the scene ===

According to early research by '''expwnent'''{{cite forum|112831/3536975}}:

The minecart has 3 variables for velocity. Velocity can be thought of as tiles per 100000 ticks, so a velocity of one hundred thousand means a cart travels one tile per tick. By going down a large number of ramps, a maximum velocity of 270,000 can be reached, which presents the limit for most practical applications. Short bursts of (much) higher speeds are possible through carefully planned collisions of high-speed carts {{cite forum|137557/5145499}}. (See [[#Perfectly Elastic Collisions|Perfectly Elastic Collisions]].)

Every tick the cart adjusts sub-tile position units by the amount of their velocity, as well as adjusts velocity depending on current tile (speed is reduced by the "friction" of the tile, or accelerated if going "down" a ramp). On flat (non-ramp) tiles, the cart will move to the next tile when the sub-tile position goes either above 100,000 or below 0, (or several tiles if velocity is over 100,000,) and 100,000 is either added or subtracted to sub-tile position to restart the count to the next tile change.

Since most deceleration and acceleration is applied per step, with the notable exception of corners, a cart going at twice the speed of another one can cover about four times the distance in a straight line, but only twice the distance along a winding track with very many corners.

A push will teleport a cart to the beginning of the next tile (NOT the middle!) in one tick with 19990 speed (10 speed is lost due to track friction), while a roller will give a cart the roller's set speed, and it will start to accumulate regular track friction past the middle of the roller tile. Some track features will affect a minecart when it is past the middle of the previous tile: entering a ramp or a hole/drop will happen when the cart has left the middle of the previous tile, and the ramp will gain additional distance unit depending on the leftover units from the previous tile. When a cart leaves a ramp it will emerge after one tick in the middle of the next regular tile, so its entry coordinate is "50000-speed+friction". Rollers also affect the speed of minecart from the middle of the previous tile.

Friction of tiles:
{| class="wikitable"
|-
! Tile
! Friction
! Comment
|-
| Tracks
| 10
|-
| Ground/Floor
| 200
|-
| Unusable ramp
| 10
|-
| Upwards ramp
| 4910 (10+4900)
|-
| Downwards ramp
| -4890 (10-4900)
|-
| Roller
| ±100000 (but capped by the set speed)
|-
| Corner track
| 10
| Speed reduced by 1000 upon leaving the corner tile
|-
| Track stop (highest)
| 50000
|-
| Track stop (high)
| 10000
|-
| Track stop (medium)
| 500
|-
| Track stop (low)
| 50
|-
| Track stop (lowest)
| 10
|-
| Water 1-6
| Additional (WaterLevel - 1) * 100
| rowspan="2" | [[#Skipping|See Skipping]]
|-
| Magma 1-6
| Additional (WaterLevel - 1) * 500
|-
| Empty space
| 0
|}

Water of depth 7/7 provides a friction of about 10000 per step, as does maximum-depth magma. This higher friction may not apply to very slow-moving carts.

Impulse sources:
{| class="wikitable"
|-
! Feature
! Speed
|-
| Push
| 20000
|-
| Roller lowest
| 10000
|-
| Roller low
| 20000
|-
| Roller medium
| 30000
|-
| Roller high
| 40000
|-
| Roller Highest
| 50000
|-
|}

Note, again, that nearly all of these values are applied ''per tick'', rather than ''per tile''. The exceptions are curves, which is 1k deceleration per direction change at the half-way point of the tile, and rollers, which ''set'' the speed every tick. This makes rollers particularly useful in high-deceleration situations, such as underwater, but require that ''nearly every tile'' in such high-deceleration situations have a roller.

A cart heading up a ramp can experience deceleration on multiple ticks, (and stays on the tile more ticks the slower it is going, resulting in greater deceleration,) and as such, a cart leaving a "Highest Speed" roller with 50k velocity will not be able to climb 10 consecutive straight ramps, since they are ''not'' "5k deceleration each". In fact, the first ramp not on a roller will be -15k velocity, and, depending slightly upon other factors of "remainder" x position, the second may completely cancel forward momentum, and send it rolling back down, where it will bounce off the roller repeatedly. Using rollers to power carts up ramps reliably requires rollers every other un-rollered ramp. Fortunately, rollers can be built upon ramps, themselves, which allows for rollers to only need to be built every other floor. (Exploiting the [[#Checkpoint Effect|checkpoint effect]] can allow one to bypass this requirement.)

=== Sub-tile Positions and Velocity ===
Carts store six values that are unique to them. Three sub-tile position values, and three velocity values. (X, Y, and Z.)

Note that the Z position and velocity only matter when a cart is in flight. (See [[#Falling|Falling]] and [[#Cart Jumps|Cart Jumps]].)

Each non-ramp tile is functionally composed of a value between 0 and 100,000, with a "centered" cart sitting at the 50,000 point in all three directions. When a cart has velocity, it is added or subtracted from the current position every tick, and then a friction force is applied to the cart.

In essence, every sub-tile position unit is a decimal value of a tile, 0.000001 tiles, in a game that largely prefers integer values.

When carts move beyond the maximum or minimum value of a tile, they physically move a tile on the map, and start at the far end of the sub-tile position the next tile. (I.E., traveling West, a cart that starts a tick at 15,000 X sub-tile position and has an X velocity of -20,000 would move to -5000 X sub-tile position, which is out of bounds for that tile. As such, it will travel one tile West, and start the next tick at 95,000 X sub-tile position. It will also lose 10 velocity in that tick due to friction with the track if it is on a track, or 100 velocity if it is on regular ground, or no velocity if it is airborne.)

Ramp tiles are longer, approximately 144,000 in the direction where it "slants downward", (to approximate a 45 degree slope, it is square root of two times longer,) and centered at 72,000. Because of this, a cart with no velocity dropped from a hatch will land at the center of a tile, at position 72,000, and 72,000, and will start rolling in the ramp's "downward" direction, picking up the ramp's acceleration (4890 per tick in the direction of the ramp's "downward" direction) every single tick, then moving that sub-tile amount every tick. (This results in a cart that takes 5 ticks of acceleration to leave its ramp - 6 ticks overall - and to leave the ramp with about 23k velocity, slightly more than a push.) When it enters another ramp ''facing the same direction downwards'', a cart will start at the 0 or 144,000 position, and have twice as far to travel. This means that if a cart enters a ramp from the side, it will gain twice the momentum of simply starting at the midpoint of a ramp.

Note that passing from one direction of ramp to another or to flat terrain causes unintuitive behavior, "teleporting" to the midpoint of another tile in what is called the "[[#Checkpoint Effect|checkpoint effect]]".

Note, however, that sub-tile positions are carried over from tile-to-tile. This separate tracking of velocity and position between X and Y can lead to problems with diagonal motion:

{{diagram|spaces=yes|\
z0 z-1
▒║▒ ▒▒▒
═▼═ ▒╬▒
▒ ▒ ▒║▒
▒ : Wall
═, ║ : Track
╬ : Track and Ramp
}}

If a cart is passing West-to-East over this setup, the valid ramp to the South will apply "Southward" acceleration to the cart (-Y velocity) as it passes through the ramp tile. Assuming it only spends one tick in that tile, it will still have gained about -5k Y velocity, which will still apply motion Southward. If the tracks continue straight for another 11 tiles, it will have accumulated enough Southward motion to try to move a tile South, even if all tracks are facing East-West.

'''Non-curving tracks do not correct this motion'''.

They don't "tip back over" without adjustments in the track. Any value of sideways motion on tracks larger than 990 will lead to a derailment. (Lower values will be nullified by friction before they are enough to lead to derailment, but there is currently no way to apply such a small amount of velocity.)

If the tile to the South is a wall at that point, it will be considered a collision with a wall that ''halts all motion''. If the tile is open, it will generate a diagonal track derailment that will send a cart flying until it strikes a wall, at which point it will not re-rail itself. In almost any circumstance, this is undesirable behavior.

The only way to appropriately deal with this is to either cancel out this behavior with an equal amount of acceleration in the opposite direction, or to take a curve.

Note, again, that sub-track position is saved in both directions, so when a cart approaches a curve, it will already have a shorter or longer distance past the curve when it makes the turn.

Curves are applied "halfway through" a tile. If a cart is moving East, and approaches a North-East track at 20k velocity, and friction is eliminated for the purposes of a cleaner demonstration, then when it enters the tile at sub-tile point 0 X, and 50k Y at the start of a tick, it will then move 20k East (+X) the next tick, and be at 20k X sub-tile position, and 50k Y sub-tile position. Next tick, it is at 40k X sub-tile position, and 50k Y sub-tile position. The next tick would take it to 60k X, but that's past the halfway point, so it stops at 50k, turns (and thus loses 1k velocity, but translates the rest from X-velocity to Y-velocity) and travels another 10k. It is now at 50k X sub-tile position, and 60k Y sub-tile position. Next tick, it travels at 19k velocity North, and so moves to 50k X sub-tile position, and 79k Y sub-tile position. Then in two more turns, it leaves to the North.

In the case of diagonal motion due to having velocities in X and Y at the same time, it is critical that the direction the cart is heading in reaches that halfway point in a curve before the cart leaves the track off its sideways velocity direction. If it does so, all sideways velocity is lost, as forwards velocity ''overwrites'' sideways velocity in a curve. If, in that example in the paragraph above, the cart entered at 0 X sub-tile position with 20k X velocity, and 40k Y sub-tile position and -1k Y sub-tile position, it would take that "curve" (or rather, redirection of velocity) on the third turn, while it is at 38k Y sub-tile position to start with, and then move to 47k Y sub-tile position at the end of that tick. It would then move to 56k Y sub-tile position in the following turn, and take 3 turns, rather than just 2, to clear the tile.

But, most importantly, it would be centered in the X sub-tile position, and with the negligible difference of an extra tick, all sideways velocity could be safely ignored.

There are two common ways to gain sideways velocity: Rollers facing perpendicular to the cart's travel path (which, as covered above, are almost always a bad idea, as it is easier to push ''against'' the travel direction of a cart into a curve, which redirects all velocity in the new direction,) and [[#Corner Ramp Derail|corner ramps]], and require a curved track to compensate for sideways velocity within a few tiles.

=== Track Direction Irrelevance ===
Carts that are traveling independently, (that is, not guided,) only care that tracks ''are'' on the tile, not which direction the tracks actually move. Tracks respect only curves (with two exits) and ramps.

This means, for example, that the following tracks, when a (non-guided) cart travels from West-to-East, are functionally identical in effect:

{{diagram|spaces=yes|\
A════════════B A╬║╚╔╣╩╦╠╥╨╞╡B
}}

This is because so far as the cart is concerned, only valid ramps and curves with two exits where there is no exit in the path they are traveling matters.

Hence, if a minecart encounters the end of the track or a T junction with no "exit" in its movement direction, it will simply leave the track and continue on its course in a straight line until it encounters an obstacle, slows to a stop, or encounters another track even if the tile at which it joins the new track instantly sends it around a corner.

In fact, in a track designed for pushes or rides, a "║", a "╦", a "╬", and a "╥" are ''only different in appearance'', and are ignored by an unguided cart, which will continue in its current direction, regardless of the track. For any purpose but guided tracks, ''only curves and ramps matter at all''.

Tracks like T-junctions, however, ''are'' respected by dwarves guiding carts, who will lift and carry carts if they cannot find a valid track to their destination, and can choose to follow any orthogonal direction at a four-way junction in much the same way as they normally pathfind. What this functionally means is that T and four-way junctions ''only guide dwarves hauling a cart, not carts, themselves''.

Carts only check for curves when they are halfway through a tile. When they get there, they look to see if their path has no exit. (That is, if it is traveling East, it checks if there is an East exit.) If there is, it ignores all other track directions, and keeps traveling. If there is not, it checks to see if there are only two exits to the track, and if one of those directions was the direction it "came from". (That is, if traveling West from the East, it checks if there is a valid exit to the West, and if not, if there is an East exit and EITHER a North or South exit.) If there is not, it ignores the track anyway, and keeps on traveling as though it were still on track.

If there is a curve the cart will respect, it checks for derailment. Carts derail at a speed whose exact number is currently unquantified, but is over 50k. Carts at this critical speed will then check for blockages of their forward path. If there is an obstacle to their path, which may be a wall or even furniture or buildings like a door or impassible workshop tile, they will not derail and respect the curve, anyway. Derailing carts do not "[[#Cart Jumps|jump]]" unless they hit completely untracked tile or an invalid ramp, but simply ignore the layout of the tracks entirely. With invalid ramps, this means not respecting the ramp, and likely results in collision with a wall, zeroing of all velocity, and a cart that requires manual retrieval.

If the cart is traveling at a speed that will not derail, or is forced to turn by a supporting wall, it will subtract 1000 from the "forwards" velocity of the cart, and redirect all forward velocity to the direction of the curve. This change in the direction of velocity ''overwrites'' any "diagonal" velocity, which can prevent diagonal velocity derailments, but any perpendicular velocity is not preserved, and is instead discarded.

=== Valid and Invalid Ramps ===
Ramps are functionally defined for cart purposes as being a tile which exerts an acceleration force upon its "downward slope", and which allows connection to tracks a z-level above or below. This downward slope requires a cart to have one ''and exactly one'' carved exit to the tile that is the "bottom" of the ramp. Ramps accelerate carts in this "downward" direction (possibly leading to [[#Corner Ramp Derail|diagonal movement]]), and the deceleration of an "uphill" ramp is actually just the acceleration being applied against the direction of a cart's movement.

This is where players can find an exploit in the behavior of ramps - if there are ''two'' "downhill" exits to a ramp (such as a "T junction" on a ramp where only one exit faces a wall), then the ramp provides no acceleration ''or'' deceleration, allowing carts to travel up ramps without any loss of momentum except for the standard "flat track" deceleration, because as far as the cart is concerned, the track ''is'' flat. (A T junction is also not a curve, so the track is considered flat and straight no matter what direction the cart is traveling.)

Similar effects can be achieved when there are ''no'' "downhill" exits to a ramp. This may be the case if you have, for example, an East-West track with a one-tile channel with a ramp in it. The cart will travel through the "dip" with no change in velocity. It can also be the case if you abuse the [[#Track Direction Irrelevance|Track Direction Irrelevance]], and set only exits ''up'' the ramp, and none leading ''down'' the ramp. For example, if a cart is traveling from West to East up a slope, only carving East exits on each tile of ramp will make the cart travel up the ramp, and then recognize the tile it is on as being a "flat" tile, thus ignoring any deceleration from traveling uphill.

Note that this effect only reliably occurs at below-derail speeds as the cart will treat the ramp as an invitation for a ramp jump otherwise. (This almost always results in a collision with a wall that will stop forward progress.)

=== Falling ===
When falling, a minecart appears to cause no damage upon collision, possibly to allow cart "stacking" across Z-levels.{{cite devlog|2012|04|06}} A dwarf riding in a minecart that is dropped multiple z-levels suffers normal fall damage. Minecarts can fall through up/down stairs.

While airborne, carts do not feel the effects of friction in any horizontal direction, and will continue until they strike an obstacle. Carts that land on tracks instantly re-rail themselves regardless of track directionality.

Falling carts accelerate similarly to the way that a ramp will accelerate a cart in a special z-only velocity that only applies to airborne carts. (Actually, acceleration due to gravity in freefall seems curiously slightly ''slower'' than ramp acceleration.) Ramp acceleration, while it logically should be partially z-directional, is only recorded as x- or y-directional, and there is no translation of z-directional velocity upon landing. Landing carts zero out their vertical velocity upon landing, even when landing on ramps, although carts that had horizontal momentum while falling preserve it.

This means a cart falling (from a hatch, thus with no horizontal speed) onto a track ramp is accelerated as if starting from the middle of the ramp - i.e. to the same speed, no matter how many Z-levels it was dropped, vertical velocity is negated. {{cite forum|144328/5701211}}

Carts falling onto a floor can, however, cause damage to creatures ''one tile below the floor''. This can be used in an [[exploit]] called a "thumper", where carts are caused to repeatedly fall on a floor above an entrance to the fort, inflicting significant damage (as though it were a collision) on those below the cart.

=== Cart Jumps ===
Carts that cross off of "up" ramps relative to their current direction of travel, which do not have a ceiling above them, are traveling above derail speed, and do not have valid ramp track before them can translate a portion of their horizontal velocity into vertical velocity, causing a cart to be projected into the air until vertical velocity is negated and overcome by the gravitational acceleration. Because downwards acceleration is applied per-tick, this creates a reasonable facsimile of the parabolic motion of an actual object rolled up a ramp and launched with significant speed.

{{diagram|spaces=yes|\
z0 z0 hiding ramps z+1 A z+1 B (hidden ramp)
▒▒▒▒▒▒▒▒▒▒▒▒ ▒▒▒▒▒▒▒▒▒▒▒▒ ▒▒▒▒▒▒▒▒▒▒▒▒ ▒▒▒▒▒▒▒▒▒▒▒▒
═▲▲▲▲▲══▲▒▲═ ═╚╚╚╚╚═══▒══ ▼▼▼▼▼ ▼═▼ ▼▼▼▼▼ ▼╚▼
▒ : Wall
═ : track
▲ : Ramp
}}
In this diagram, if there is no ceiling above it, the track in z+1 A will launch its carts airborne when they travel across the ramp. z+1 B (with a ramp on the tile on the hill) will not launch the cart. The cart would also not be launched with ''any'' valid ramp, even if it does not travel in an appropriate direction, such as North/South (which the cart will ignore, as it is not a curve, anyway, although it may produce acceleration that may cause diagonal movement.)

Carts that are traveling at derail velocity will also start "jumping" from the track if it hits an un-tracked tile, flying over and ignoring any tracks until it is ready to land. Carts that land upon tracked tiles re-rail themselves, and clever designers use this feature to jump over curved track sections in one direction or another. (Retracting bridges over untracked tiles can cause jumps or not cause jumps depending upon the status of the bridge.) Minecart speed must be carefully regulated to ensure reliability of jump length.

Hitting untracked tiles at around 70k velocity creates a vertical component to acceleration that allows for jumps of around 6 (horizontal) tiles that do not actually leave the z-level the cart is on, but which do apply z-direction velocity on the cart, as per falling.

Carts that approach a downward slope at a high enough velocity will also make a jump, (or rather, ignore the ramp and fly forwards) but will not do so if the [[#Checkpoint Effect|Checkpoint Effect]] is exploited through an impulse ramp before the actual downhill as the impulse ramp "tricks" the cart into thinking it has already started going downhill. The cart will also not fly off the ramp if there is a wall and ceiling preventing any motion but going down the ramp.

=== Skipping ===
If a minecart is moving fast enough, it can skip over [[water]] or [[magma]], making splashes of [[mist]] (or [[magma mist]]) as it attempts to move on them horizontally. This horizontal movement is independent of the minecart and its content's [[weight]].

Skipping causes significant friction on the cart, and even a cart going at max speed from ramps can only make about 50 tiles without requiring re-acceleration. (Carts that decelerate enough that they do not trigger the skipping effect will, of course, sink.)

=== Corner Ramp Derail ===

Corners on upward ramps can cause diagonal movement, forcing a derail even if the cart has a wall next to it, which will force a stop when it touches a wall that forces dwarves to manually reset the cart.

This is caused by the fact that a cart, after turning the bend in the track halfway through the length of the tile, will still "accelerate down", which is now perpendicular to the movement of the cart, causing acceleration to occur in two directions. (Down corner ramps do not have this problem, as when they pass the halfway point, all perpendicular motion is added to forward motion, and after that curve, all downward acceleration is in the forward direction.)

There are two fixes to this problem. One is to simply not put corners on up ramps. The other is to take advantage of the [[#Checkpoint Effect|Checkpoint Effect]], by making a ramp (possibly including an impulse ramp) one tile in front of the ramp to make it skip through most of the tile before sideways momentum can be built.

=== Checkpoint Effect ===
The checkpoint effect, [http://www.bay12forums.com/smf/index.php?topic=144328.0 explained in depth by Larix], is an odd and highly exploitable feature of ramps where minecarts "teleport" through the next tile of track, ignoring nearly all minecart physics (except that they stop at all walls or other obstacles and only respect curves with no backing wall and invalid ramps if they are below derail speed) and passing through that tile in just a single tick, and into the next tile at the halfway point.

This effect occurs when a cart leaves a downward ramp for any other direction of tile. (This includes ramps which accelerate in different directions, even a ramp which goes from accelerating East to accelerating North due to a bend in a chain of standard down ramps in a curve.) This allows, for example, two valid straight ramps directly next to one another with a cart dropped onto one or the other with no momentum to have the cart pick up acceleration going "down" the ramp as normal, but then flying up through the "up" ramp it travels into with no loss of momentum, as though it had come from an impulse ramp. If the two ramps had at least one space of distance between them, and then a cart were dropped in, the cart would instead "rock" back and forth between the two ramps.

This seems to be because ramps have a slightly longer length than regular tiles - 144,000, rather than 100,000 distance. When this "snaps back" after a ramp, it seems to project the cart suddenly further along the track, making it jump a tile ahead even when otherwise moving at relatively low speeds.

This [[bug]] is the cause of a ''wide array'' of unexpected behavior among people who do not take this bug into account. It causes derailments or failure to climb up seemingly valid impulse elevators. In general, it makes a system that behaves extremely counter-intuitively, and operates ''any time a cart encounters a valid ramp''. At the same time, when its effect is accounted for, it is highly exploitable: It causes "perpetual motion devices" using no power when two opposing ramps are placed next to one another, since the "uphill" effect of the opposing ramp is ignored, preventing deceleration.

Another useful thing to note about this exploit is that carts traveling at no less than 72,000 or so speed (enough to travel half a ramp tile in a single tick) can travel through every tile in just one tick at no change in velocity as long as the tiles alternate between impulse ramp or actual down ramp and any other tile type. The cart checkpoints through the non-down-ramp tiles, and can pass through the (impulse) down ramp tiles in a single tick, before they can actually start gaining momentum.

{{diagram|spaces=yes|\
▒▒▒▒▒▒▒▒▒▒ ▒▒▒▒▒▒▒▒▒▒
═▲═▲═▲═▲═▲═ ═╚═╚═╚═╚═╚═
▒ : Wall
═ : Normal track
▲/╚ : N/E Track/Ramp
}}

If the cart enters from the West at less than 72,000 speed, some of those ramps will cause Eastward acceleration.

This means that an impulse ramp not contiguous to other impulse ramps has a top speed of around 75k:

{{diagram|spaces=yes|\
▒▒▒▒▒ ▒▒▒▒▒
▒╔═╗▒ ▒╔═╗▒
▒╚▲╝▒ ▒╚╗╝▒
▒▒▒▒▒ ▒▒▒▒▒
}}
This setup makes a cart that travels clockwise at a speed that fluctuates around 75k velocity. If the cart has more than 72k velocity, it fails to accelerate in the ramp, as it leaves the ramp in a single turn due to checkpointing to the halfway point. After that, the curves sap 1k velocity, and every tick saps 10 velocity.

Two contiguous impulse ramps with a same-facing "downwards slope", however, do not suffer the checkpoint effect in the second tile, giving functionally triple the space to accelerate. This means it will add velocity (at the standard rate of 4.9k per tick) up to a maximum speed of 216k.
{{diagram|spaces=yes|\
▒▒▒▒▒▒ ▒▒▒▒▒▒
▒╔══╗▒ ▒╔══╗▒
▒╚▲▲╝▒ ▒╚╗╗╝▒
▒▒▒▒▒▒ ▒▒▒▒▒▒
}}
This example results in a cart moving three times as fast as the previous cart.

Three successive ramps results in the highest attainable speeds.

In practical terms, this means that only consecutive ramps should be used for high acceleration, but singleton ramps can be used to have speeds that are somewhat regulated.

=== Stacking ===
If a minecart lands on top of another minecart, they may form a stack, with the upper cart on the z-level above the lower. Subsequent carts do not form a stack, but rather quantum stockpile in the same space. This behaviour is useful for [[megaprojects]] and [[trap design]] with minecarts as the weaponry. Moderation should still be exercised: carts take longer to fall into a "stacking" tile already occupied by other carts and will spend that time "hanging" in the air above the stack. This can lead to following carts striking them, which can cause all kinds of malfunctions. The extra time is two game steps for every cart already in the stack, which doesn't hurt stacks of ten carts very much but makes stacks of 100+ rather impractical.

These minecarts on the upper level generally need to be struck with another minecart to move out, or have their support removed. The latter option is safest done by shooting it away with another minecart, manual removal of a stack-supporting cart typically causes the next cart from the stack to [[fun|fall on top]] of the hauler.

=== Perfectly Elastic Collisions ===
Minecart collisions are perfectly elastic, meaning that not only do minecarts not take damage, but that two carts that are rolling which have frontal collisions of near-similar speed, and where one cart is no more than twice the mass of the other cart, will result in a billiard-ball-like effect of the lighter cart bouncing off the heavier cart with a proportional speed increase dependent upon the relative momentum behind the heavier cart.

Using this trick with carts already at the 270,000 maximum speed from ramps can result in "supersonic" carts traveling at speeds in the millions (travelling a dozen tiles per tick), but where they are suddenly subject to 10,000 units of "terminal velocity" friction per tick. [http://www.bay12forums.com/smf/index.php?topic=137557.0 Thread with SCIENCE here].

While hypothetically capable of launching a minecart into orbit when used in conjunction with a ramp, no cargo can be contained in the launched cart, as the collisions will force ejections of the cargo. Your "unwilling volunteer" [[goblin]] space pioneers will simply become paste underneath the wheels of an extreme high-speed cart.

== Non-standard uses ==
Minecarts include some interesting characteristics that have motivated uses beyond hauling. They can be useful for creating fully-automated [[exploit|quantum stockpiles]] and [[garbage disposal]]s. Storing perishable goods (meat, meals, etc.) inside a minecart appears to guard against rot and vermin.
Minecarts can be [[Trap_design#Minecarts|used as weapons]], or as (hopefully non-fatal) triggers to restart stalled [[healthcare]]. They can also be used to time/control game events, either using a basic [[repeater]] or much more advanced [[minecart logic]].
Minecarts trigger [[pressure plate]]s, which means a trap can be designed to trigger when a thief attempts to steal a minecart.
A pressure plate can be used as automatic and more precise custom "launch when full enough" system - as long as weight of your minecarts stays the same. You cannot build a hatch or roller on the same tile, so launch by bumping with another cart. {{cite forum|15096/4580050}}
Dwarves riding minecarts can attack enemies within reach (which goes back to dev log). This applies to shooting, and they actually can hit targets while riding by.{{cite forum|109460/5266119}} Whether a minecart protects the rider and how it interacts with dodging is not known yet. Minecart riders can also [[Swimming#Minecart_training|train swimming]] and [[Megaprojects#Surveillance_Track|detect ambushers]].

== Adventure mode ==
In addition to being used for hauling, minecarts can also be ridden in [[adventure mode]]. (Adapted from forum thread {{cite forum|122903/4258212}})

# If the minecart is in your inventory, drop it. If it is already on the ground, proceed to step 2.
# Press {{k|u}} when you are 1 tile away from the minecart (or standing on the same tile as the minecart).
# You will be presented with the following options:
[[File:minecart adventure mode menu.png|left]]
{{clear}}
* If you {{DFtext|Push}} the minecart, it will move a few tiles in the direction you chose. Physics comes into play here, so it will gain/lose speed depending on the usual factors.
* If you {{DFtext|Ride}} the minecart, you will hop into the minecart, even if you were a tile away, and it will move in the chosen direction with you in it. It will gain/lose speed depending on the usual factors. Whilst the minecart is in motion, you should press {{k|.}} to skip your turn; if you attempt to move whilst the minecart is still in motion, the laws of physics come into play, and you will take [[wound|damage]]. Alternatively, you can push the minecart whilst it's still in motion (although it's unclear how one can bend [[physics]] so as to push a moving minecart whilst inside the minecart). If you push it in the same direction you are already travelling in, you will greatly increase the minecart's velocity. You can also push it in different directions, and this will cause it to gradually change direction-the amount of pushes this requires depends on the minecart's velocity. Once the minecart has stopped moving, you may move out of it safely, or you may want to give it another push. Note that if you push a minecart right after having ridden it (still on the same tile as the minecart), it will act as though you chose to ''ride'' it.

If you want to test this out without creating an adventurer, the [[object testing arena]] allows you to spawn minecarts ({{k|k}}-{{k|c}}-{{k|n}})

== Forging and Melting ==
* Metal minecarts cost '''two''' [[metal]] bars to forge, or '''six''' [[adamantine]] wafers.
* When a non-adamantine metal minecart is melted down, it will return '''1.8''' metal bars, for an '''efficiency of 90%'''.
* When an adamantine minecart is melted down, it will produce '''1.8''' wafers, for an '''efficiency of 30%'''.

== See also ==
* [http://www.bay12forums.com/smf/index.php?topic=109460.0 The "How Does Minecart" Thread] by '''Girlinhat''' et al.
* [http://www.bay12forums.com/smf/index.php?topic=112831.0 SCIENCE: Quantifying minecart physics] by '''Snaake''' et al.
* [http://www.bay12forums.com/smf/index.php?topic=129676.0 How to build a Multi-cart Ore to Magma Minecart Project without needing power] by '''WanderingKid'''.
* [http://www.bay12forums.com/smf/index.php?topic=144328.0 My very own Minecart Education Thread. Ten Lessons, now complete.] by '''Larix'''.

== Bugs ==
*A dwarf will drop her [[child|baby]], if she has one, when boarding a minecart set to be ridden.
*Dwarves have no concept of traffic safety and will walk into busy minecart lines to retrieve objects, often with deadly consequences. This is especially problematic in [[Swimming#Minecart_training|clever applications]] depending on dwarves riding the carts very frequently, because they have a bad habit of dumping their worn clothes on the tracks after a minecart ride. Adding an automatically-operated [[hatch cover]] at the end of such a ride can help prevent [[unfortunate accident]]s.
*Dwarves cannot guide a minecart through an unlocked door unless another dwarf opens the door.{{bug|6056}}
*It is possible for a creature and minecart moving towards each other to pass without collision if they exchange tiles in the same tick.
*After a minecart ride, a dwarf will sometimes haul the minecart to a storage stockpile, leaving another dwarf to haul the vehicle back to the route.
*Minecarts falling onto a floor injure creatures in the tile below the floor.{{bug|6068}}
*A minecart's initial velocity is not affected by weight, when pushed or launched from rollers.{{bug|6296}}
*Removing a stop that has a vehicle waiting on it may cause the game to crash.{{bug|5980}}

{{Category|Fortress mode}}
{{Category|Interface}}

[[ru:Minecart]]

Minecart

2015-06-21T03:33:14Z

NW Kohaku: /* Physics */ Adding internal links.

{{Quality|Masterwork|08:15, 19 May 2015 (UTC)}}
{{av}}
A '''minecart''' is a [[tool]] intended for [[hauling]], introduced in version 0.34.08. It can be made of [[wood]] at a [[carpenter's workshop]] or [[metal]] at a [[metalsmith's forge]] (using the [[Metal crafter|metalcrafting]] labor.) Minecarts store up to five times as many items as [[wheelbarrow]]s and are quite a bit faster than dwarves hauling objects by hand, but have the disadvantages of requiring a dedicated track network, a complex route planning phase, and the possibility of dwarves [[Fun|blundering into the path of carts filled with lead ore]]. Tracks may be carved into stone, or [[Construction|constructed]]; the latter allows above-ground routes, but these are more difficult to set up due to their additional [[building material|material requirements]].

Just like wheelbarrows, minecarts are considered [[item]]s and are stored in a [[furniture]] [[stockpile]]. Despite their five-times-greater capacity, they are only 33% larger than wheelbarrows and are identical in base [[item value|value]] when made from the same [[material]] (the value may differ due to the [[item quality]]). [[thief|Thieves]] or even mischievous animals can steal minecarts, even when they are moving on a track{{cite forum|109460/3289070}}. However, minecarts moving fast enough or being ridden cannot be stolen.

Although most of the utility of minecarts is in [[fortress mode]], an [[adventure mode|adventurer]] can also ride in a minecart. Adventurers can also pick up and relocate minecarts.

The invention of minecarts revolutionized the [[minecart logic|Science of Dwarfputing]] by enabling smaller, faster logic systems to be built.

== Basic Minecart Usage ==
Minecarts can be used to swiftly transport dwarves, [[flow|fluids]], and/or large amounts of items, but before you have a functional minecart there are several preconditions that need to be met. First of all you need an actual minecart, constructed either in a [[carpenter's workshop]] or [[metalsmith's forge]]. For the minecart to be able to move you also need to carve (with {{k|d}} {{k|T}}) or construct (with {{k|b}} {{k|C}} {{k|T}}) a track, which could be as simple as a straight line. Finally you need to construct stops on your track (with {{k|b}} {{k|C}} {{k|S}}) where the minecart will start and stop.

After you have created the stops and assigned a cart to the track, you must create logic routes connecting several stops and designate starting conditions for each stop. This is done with the {{k|h}}auling key. The most basic conditions are how the cart's movement is initiated and in which direction the cart should start moving. Carts can be either be Pushed (a dwarf stands at a stop and gives the cart a single push) or Guided (a dwarf continually pushes the cart forward, guiding it along the track). The [[hauling]] [[labor]] required for pushing and guiding carts is called "Push/Haul Vehicles" and is turned on by default.

To control which items to transport you can add conditions specifying: (1) which kind of items to be loaded, and unloaded, (2) stockpile links to define which stockpile(s) the items should be un/loaded to and from.

===Capacity and weights ===
Minecarts have five times the [[Weight|capacity]] of [[wheelbarrow]]s.

'''Examples of the capacity of one cart'''
{| class="wikitable"
|-
! Item
! Amount
|-
| [[stone]]
| 5
|-
| [[wood|log]]
| 10
|-
| [[block]]/[[bar]]
| 83
|-
| [[Kitchen|prepared meals]]
| 500
|-
| [[Trap_component#Spiked_ball|spiked balls]]
| 500
|-
| [[Weapon#Native_weapons|mace]]
| 625
|-
| [[Weapon#Native_weapons|spears]]
| 1250
|-
| [[cloth]]
| 2500
|}

The weight of the loaded minecart does not affect the initial velocity received from pushing or launching from a roller. However, the load of a minecart ''does'' affect whether a [[pressure plate]] triggers or not, based on the pressure plate's setting.

'''Weights of different carts'''

{| class="wikitable"
|-
! Type of cart
! Empty cart
! Fully loaded (items)
|-
| oaken minecart
| 28Γ
| 378Γ (10 oak logs)
|-
| platinum minecart
| 856Γ
| 10482Γ (83 gold bars)
|}

The weight of a minecart is one twenty-fifth (1/25) the [[density]] of its material in Urists. Because pressure plates can be set to trigger at intervals of 50 Urists, minecarts with weights just under a multiple of 50 are ideal for switching based on whether they're full or empty. The best minecart materials for full/empty switching are as follows:

{| class="wikitable sortable"
|-
! Material !! Minecart weight !! Content weight required to trigger !! Banana roasts required to trigger (for scale)
|-
| [[Bismuth]] (moods only) || 391 || 9 || 15
|-
| [[Brass]] || 342 || 8 || 14
|-
| [[Electrum]] || 596 || 4 || 7
|-
| [[Fine pewter]] || 291 || 9 || 15
|-
| [[Glumprong]] || 48 || 2 || 4
|-
| [[Lay pewter]] || 291 || 9 || 15
|-
| [[Nickel silver]] || 346 || 4 || 7
|-
| [[Tin]] || 291 || 9 || 15
|-
| [[Trifle pewter]] || 291 || 9 || 15
|}

=== Creating tracks ===
Minecart tracks are made up of contiguous track, tracked ramp, or bridge tiles. Track tiles and tracked ramp tiles have a direction or series of directions associated with them. These directions dictate which directions a minecart on a given tile may move from that tile. For example, a Track NE (northeast) tile allows a minecart on it to move either north or east from its present position. Therefore, if you want your minecart to move east along a straight piece of track, then return west using that same track, you would need to use EW tracks so that the cart could travel east initially, then return west over the same track. Excluding designs in which the cart will "jump" tracks via a drop or other ramp, tracks must be valid end to end to work for most looped or straight-track applications. A single east only track tile in your line of east-west tracks will cause any route using the track to fail the moment it tries to go the wrong way over that tile. Minecart tracks can be built in two ways: Engraved/carved or constructed. A given minecart track need not use engraved or constructed elements exclusively, as the two methods can be used interchangeably depending on the needs of a given section of track. The way the tracks are built is slightly different between the two, as explained below.

====Simple tracks====

'''Carved'''

A single-tile wide strip of natural stone can be designated to be [[Engraver|carved]] (with {{K|d}} {{k|T}}), which will create a straight two-way track. The creation of corners, crossings, and T-junctions is as simple as designating another strip of track that overlaps an existent or newly designated track. Engraved tracks are removed by [[smoothing]] the rock they're on, which results in a smooth floor (that can be re-engraved if necessary), or by building a [[floor]] on top and subsequently removing it. Dwarves can carve corner tracks in one pass by designating the track carving twice and canceling unwanted carvings (with {{K|d}} {{K|x}}). Tracks can be engraved in any natural floor tile, rough, smooth and even over engravings, providing an easy method to remove low-quality or undesired floor engravings. Once a track has been engraved, it's important to check the track directions for each tile in the route carefully to make sure no mistakes were made by yourself or the game's track engraving logic.

'''Constructed'''

Tracks can also be built as regular [[construction]]s (through {{K|b}} {{K|C}} {{K|T}}). This method is resource-expensive, since each track tile requires one stone, [[bar]], or [[block]] for construction, and time-consuming, since you can't designate strips longer than 10 tiles at a time. Corners, crossings, T-junctions, and ramps also have to be designated individually. However, it is usually the only way to build tracks above ground or on soil (barring the [[Obsidian farming|creation of obsidian]]). Constructed tracks are designated for removal like any regular construction; be aware that removing track ramps built on top of natural ones will also remove the original ramp, leaving a flat floor.

====Ramps====

'''Carved'''

The carving of natural ramps is a little more confusing: to carve a two-way track on a ramp (natural only, does not work on constructed ramps), you must designate the track '''starting on the ramp and one square beyond''' in the direction you want the track to go. For the side of the ramp square you want to head upward, there '''must''' be either a natural or constructed wall in the square next to it, otherwise the game assumes you are trying to carve it on the same level -- this can result in the track being carved underneath a door or other object. If you have accidentally done this, you can correct it by smoothing the ramp and constructing a single square of wall next to it, then re-carving the ramp correctly. (However, the wall must stay there permanently; removing it will disconnect the track.)

'''Constructed'''

When constructing track ramps, the stated direction should be the same as the connected tracks. For example, a track going up from West to East would require, starting from the West, a Track (EW), a Track/Ramp (EW) and a Wall behind the ramp, underneath the section of track above it. Incorrectly placed ramps result in minecarts ignoring the ramp and crashing into the supporting wall. They will not, however, display as unusable as when the supporting wall is missing.

'''Examples of ramps'''

A simple ramp would look like this:
{{diagram|spaces=yes|\
z +0 z +1
░░░░ ░░░░
═▲o ░▼═
░░░░ ░░░░
o : wall
}}

Carving track corners into ramps is rather unintuitive and complicated. Since engraving tracks always requires two tiles to connect in a straight line as input, you have to give two separate designations for a single job: a track bit from the ramp tile to the "below" direction and another one to the wall of the "upward" direction. If you wanted to change direction on a ramp from east to north:
{{diagram|spaces=yes|\
z +0 z +1
░░░░░ ░░░░░
░░░░░ ══╗░░
=▲░░ ░░▼░░
░░░░░ ░░░░░
}}
you would need to connect the ramp on z +0 both to the west and to the north by issuing two "carve track" commands, one selecting the ramp and the track tile to the west, and another connecting the ramp tile with the wall to the north. An engraver would then carve a NW track corner into the ramp, allowing carts to pass the corner correctly both going up and down. Such track corners are perfectly serviceable for guided carts, but moving down a route of several of them by pushed or ridden cart is problematic - ramps on corners behave very counter-intuitively, resulting in loss of speed when going down and diagonal movement when going up.

Moving to and from ramps (or between ramps "pointing" in different directions0 causes some non-trivial adjustments to speed and even moving along the tiles at a fixed speed ''unrelated to the entry/exit velocity values'', because transitions to/from ramps are processed differently and are not to be "skipped". This affects compact track/ramp combinations (such as e.g. a simple 2x2 ramp spiral) most, and combined with bouncing often makes them work not in the way one could expect. {{cite forum|144328/5705102}}

{{anchor|Tracks}}

=== Hauling route ===
A hauling route is a list of directions describing how and under what conditions a minecart will move. The proper setting up of routes is essential for a working rail system. Routes, stops, departure conditions and stockpile links are managed from the {{k|h}}auling menu.

==== Route ====
A route defines the path a minecart will take along a track, as well as under what conditions it will move or stop moving. A route is made up of stops. Stops are precisely what they sound like, a position on the track at which you want a minecart to stop. A minecart track might use as little as a single stop for a looped track, which will serve as both a starting and stopping point for the cart, or it could contain many stops, perhaps to load supplies or wait for a bridge to be manually lowered, before reaching its destination or returning to its starting point. It is important to note that you only need to place stops on a route where you actually want the cart to stop and wait for some action to occur. They are not needed to help navigate the cart along the track beyond telling it where on the track to stop.

New routes are created with the {{k|h}}auling key. Existing ones can be removed (without confirmation) with the {{k|x}} key, and also {{k|n}}icknamed. Before operating, the route must have a {{k|v}}ehicle assigned to it (this can be done with either the route or a stop selected). Assigning a full minecart to a route may result in a slow hauling job if the contents are heavy.

==== Stops ====
Stops are the individual waypoints that make up a hauling route. A given stop consists of the location of a tile, as well as conditions describing when, where, and how a cart should be moved after being stopped at that tile. Stops can be created from within the {{k|h}}auling menu, by placing the cursor over a tile and hitting {{k|s}} while highlighting the route (or a stop within) you've already designated. A minecart will begin its route at the first stop created, and continue through each subsequent stop, being guided, pushed, or ridden from each stop to the next depending on the conditions specified. In many basic minecart applications, the cart will end up at the same stop it began at, though this is not always the case. It is important to note that hauling stop order is enforced, even if there is no track. A dwarf will drag the cart overland back to a skipped stop in the route's list if your tracks bypass it somehow.

Once a stop has been placed, it is given a default set of conditions under which to move the minecart if it is stopped there. Each new stop gets the same default conditions regardless of the track it is placed upon (e.g. guide the cart to the north). For this reason new stops might get marked by yellow exclamation marks ({{DFtext|!|#ff0}}) due to invalid directions. One important thing to note is that as you place additional stops, the display will show paths between the stops you have defined. However, this is '''not''' necessarily the actual route the minecart will take once the route is in operation. For example, if a route were defined with two stops at opposite ends of a track with many twists and turns, a line will be drawn directly between those stops to show the order in which they will be visited. These route lines may crisscross all over the tracks, but so long as the track is valid end to end, the cart will follow the track from one stop to the next, even across twists, turns, and z-level changes. Stops, which are the steps that make up a route, should not be confused with Track Stops, described below.

===== Stockpile links =====
By placing the cursor on top of a stockpile and using {{k|s}}, you can create stockpile links while defining a hauling stop. Links can also be redefined by selecting them, placing the cursor over a different stockpile, and pressing {{k|p}}. The cart will then be filled by items present in its various linked stockpiles in preference to other items. Note that bins should be used with caution in stockpiles that are linked to minecarts. Bins cause problems when used with the "Desired Items" list in a stop's conditions. For example, if a minecart is set to accept only granite blocks, and to depart north when it is 100% full of granite blocks, it will not depart if any of those granite blocks are in bins, even if bins are also included in the desired items list. Two solutions to this problem exist as of v0.40.24. First, bins can be disallowed in stockpiles that are linked to stops. Alternatively, bins '''can''' be used in conjunction with minecarts provided that the minecart's departure conditions use only "any items" instead of "desired items." This option can be toggled in the advanced conditions menu for a stop, accessible via the {{key|C|}} key. The cart's contents can still be controlled by specifying what items are allowed in the linked stockpile.

===== Departure condition =====
Departure conditions involve setting conditions in which the minecart will leave on the route. Each condition includes:
# A departure mode (Guide, Ride or Push).
# An initial departure direction (NSEW). Note that this defines the initial direction of movement only. Even if a track includes many turns, as long as the initial movement direction is valid the cart will follow the minecart track thereafter.
# A timer, before which the departure condition cannot be met.
# Conditions on the amount of items in the cart.
Departure conditions are created with the {{k|n}} key. A new departure condition will read: "guide north immediately when empty of desired items". This condition can be changed between basic presets with {{k|c}}. "Advanced" mode ({{k|C}}) allows for more precise control over departure conditions: fine tuning the percentage from 0 to 100 in 25% steps ({{k|f}} and {{k|F}}), switching it being either the maximum or the minimum amount of items for the condition to be met ({{k|m}}), and whether the cart accepts all or only a specific set of items ({{k|l}}). Common to both screens are the departure mode ({{k|p}}, Push, Ride or Guide), {{k|d}}irection, and timer ({{k|t}} and {{k|T}}) options.

To have a cart only carry a specific set of items, the stop can be set to only carry "desired" items, opening the selection screen with the {{k|Enter}} key while having said stop condition selected, and toggling as desired, or it can simply be linked to a stockpile and set to depart once it is full of items from its linked stockpiles, regardless of type.

=== Track Stops ===
A Track Stop, not to be confused with a route stop, is an optional, single-tile construction which serves two purposes. First, it can be used to cancel a cart's momentum in order to slow or stop it as it passes over the Track Stop. This might be necessary if a cart were pushed down a series of ramps to its destination. Second, a Track Stop can cause a cart to automatically dump its contents as it passes over the Track Stop. Track Stops are constructed via {{k|b}} {{k|C}} {{k|S}}, and must be constructed atop an existing piece of track. If a Track Stop has been set to automatically dump a cart's contents, the cart will dump its contents in the direction indicated when it passes over the Track Stop. Depending on the friction settings chosen for the Track Stop, the cart might then stop after dumping, or it might continue on its route to another destination.

Track Stops are not mandatory; in fact, their main use is in automated rail systems. However, even in basic rail systems it can be useful to set a Track Stop to dump items: this saves time that dwarves would otherwise spend in removing items from the cart, time that is better spent driving the cart back to where it's needed. Dumping will occur even with a guided cart. '''Take care not to set Track Stops at a loading site to dump their contents''', or dwarves will never be able to fill the cart. It will dump any contents the moment they are loaded.

Counter-intuitive to their construction method, Track Stops are considered [[building]]s and must be removed by {{k|q}} {{k|x}}.
* See [[#More_on_Track_stop |More on Track Stops]]

=== Step-by-step tutorial ===

Let's construct a simple minecart route. This route will move stone blocks from an input stockpile to an output stockpile. We'll begin by creating the stockpiles:

[[File:minecart-example-1.png|Stockpiles designated.]]

The input stockpile is on the left; the output stockpile is on the right. We'll be moving blocks from left to right. Disable bins in both stockpiles, and set the input stockpile to accept only from links. Then make the stockpile take from the mason's workshop where the blocks are being produced.

Next, carve the track:

[[File:minecart-example-2.png|Track carving designation.]]

Note that the ends of the designation are uniquely shaped; this is automatic, and not anything you need to control. Now, wait for your engravers to come along and carve the track into the stone. (Your haulers will probably also fill up the input stockpile while you wait.)

In addition, while we're waiting for that to happen, we'll build an iron minecart in the forge.

[[File:minecart-example-3.png|Track carved.]]

When the track has been carved, it will look like the above (the track will be solid instead of flashing). Now, order a track stop to be constructed next to the output stockpile:

{|
| [[File:minecart-example-4.png|Track stop designation.]]
| [[File:minecart-example-5.png|Select dumping direction.]]
|}

You must press {{k|d}} three times to select the dumping direction ''before'' placing the track stop. We want our blocks to be dumped into the output stockpile east of the track stop. Then wait for a mechanic to come along and build the track stop.

[[File:minecart-example-6.png|Track stop constructed.]]

Now we'll define the actual ''route''. This is done in the {{k|h}}auling menu. Press {{k|r}} to begin defining a route. Next, move the cursor to the input end of the track, and then press {{k|s}} to define the first stop:

{|
| [[File:minecart-example-7.png|Stop 1 designation.]]
| [[File:minecart-example-8.png|Route definition, in progress.]]
|}

Move the cursor again, to the output end of the track, and press {{k|s}} again to define the second stop:

{|
| [[File:minecart-example-9.png|Stop 2 designation.]]
| [[File:minecart-example-10.png|Route definition, two stops.]]
|-
|
| [[File:minecart-example-11.png|Stops are not defined yet.]]
|}

There are several user interface features to note at this point. The stops have been positioned, but they haven't been ''defined'' yet, so there is a warning {{DFtext|!|#ff0}} symbol by each of them. In the lower right corner, we see what the {{DFtext|!|#ff0}} means. Also, note that the second stop is labeled in white, while the other two lines are grey. The white text is a selection indicator, and can be moved up and down by pressing {{k|+}}/{{k|-}}.

Next we need to define what our stops do. We want the minecart to be filled with blocks at the first stop, then travel to the second stop where it will dump its cargo, and then return. Press {{k|-}} to move the selection up to stop 1, and {{k|Enter}} to open it up. By default, the stop has three conditions:

[[File:minecart-example-12.png|Default stop definition.]]

We don't want any of these, so press {{k|x}} three times to delete them. This leaves us with a blank stop. Now we can add the conditions we actually want. Press {{k|n}} to begin adding the first condition, then {{k|d}} twice to change the direction from north to east. Then press {{k|c}} to change the condition from empty to full. This will instruct the minecart to be guided east when full of desired items.

To set the desired items, we create a stockpile link. Press {{k|s}}, then move the cursor to the input stockpile, then press {{k|p}} to select that stockpile. Now press {{k|Enter}}; this opens up a selection screen that resembles the stockpile customization screen. Move down to Blocks, {{k|e}}nable them, then (if you wish) restrict it to stone blocks.

When you've done all that, stop 1 should look like this:

[[File:minecart-example-13.png|Stop 1, defined.]]

Stop 2 is much simpler. All we need to do is have the minecart return to the input stop. So, make a condition and change the direction:

[[File:minecart-example-14.png|Stop 2, defined.]]

Finally, we just have to assign our minecart. Go back to the route definition screen, and press {{k|v}}. Select the minecart, and press {{k|Enter}}.

Now we've got everything set up:

[[File:minecart-example-15.png|Route, fully defined.]]

The V is red because the minecart hasn't been moved onto the track yet. Some dwarf will have to haul it from the forge to the first stop, by hand; this will take a while, especially if the forge is far away.

Once the minecart is in place, dwarves should fill it with blocks from the input stockpile, which will in turn be filled with blocks from the workshop where your mason has been toiling dutifully. When the minecart is full, the blocks will be dumped into the 1x1 stockpile on the right. Automatic quantum dumping!

=== Troubleshooting ===

Because of the complexity of the system, all but the most careful and experienced minecart users will encounter issues. Most route issues can be diagnosed and fixed from the {{k|h}}auling menu.

'''Symptom:''' {{DFtext|! Set dir/connect track|6:1}} message appears to the right of one or more stops

'''Possible Causes:'''
* The departure direction of the stop might be invalid. Edit the stop using {{k|Enter}} and press{{k|d}} until it is pointing in a valid direction.
* The track stop might not be built on top of a track. The track stop must be deconstructed to remedy this issue.
* Your track might not be built correctly. Make sure all connected tracks between destinations are not one-way tracks.
** This can be especially confusing with ramps. To carve a two-way track on a (natural) ramp, you must designate the ramp and one square beyond in the direction you want the track to go.
** Ramps '''must''' have a solid block on the side opposite to the track, or they will neither work nor be marked as "unusable". The solid block can be natural or constructed.
* The desired/kept items might not be configured correctly.

'''Symptom:''' The status '''0% V''' always appears to the right of one stop.

'''Possible Causes:'''
* The stop may not be set to take from a stockpile. Edit the Stop using {{k|Enter}} and make sure you see a message like "Take from Stockpile #1".
* The take conditions must correspond with the contents of the stockpile.
* The track stop may be set to dump. A track stop set to dump cannot be filled. You must either set the stop to a time-based departure or deconstruct the track stop and rebuild it without dumping. (Alternatively, with [[DFHack]] you can modify "Dump on arrival" to "No" using the {{key|q}} menu without rebuilding the stop.)
* Make sure the minecart itself has not been designated to be dumped (such as when using mass-dump).

'''Symptom:''' Dwarves fill the minecart properly, but will not move it thereafter.

'''Possible Causes:'''
* The minecart may contain items which are not included in its current stop's desired items. Check inside the minecart using the {{key|k}} and {{key|z}} keys and ensure that all items in the cart are desired items.
* The minecart may contain desired items in bins. Minecarts seem to have problems realizing that they are in fact full of desired items if some of those items are in bins, even if bins are also among the desired items for that stop. '''This cannot be solved by adding the appropriate bins to the stop's desired items.''' Either disallow bins in stockpiles you intend to load minecarts from, or set the departure conditions to rely only on percentage of total load rather than percentage of desired items using the advanced conditions menu ({{key|C}} key).

'''Symptom:''' Dwarves repeatedly attempt to load the minecart, but no items are ever loaded into it.

'''Possible Causes:'''
* This can be caused by using a Track Stop with autodumping enabled at a loading site. Every time a dwarf places an item into a cart resting on such a track stop, the item will be immediately dumped, causing unlimited, useless cart loading jobs. Autodumping Track Stops should never be used at a loading site.

'''Symptom:''' A dwarf picks up the minecart and carries it to its destination.
* See [[#Quirks|Quirks]]

=== Danger ===
Minecarts are not without <strike>danger</strike> [[fun]]. Although designating a track automatically sets the [[traffic]] designation to low, dwarves ''may'' still walk on them, and [[creature]]s ignore traffic designations altogether. If an unlucky dwarf or creature fails to [[dodger|dodge]] a minecart, they can be injured. Most of this danger can be avoided by setting the minecart {{k|h}}auling commands to guide instead of push or ride (dwarves guiding minecarts will ignore traffic restrictions), as well as by [[pasture|pasturing]] domestic animals and preventing the access of other creatures to the tracks. Note that removing the track doesn't reset that tile back to normal traffic priority, so you may wish to manually clean up traffic designation afterward. Also note that bridges that are used as tracks don't have their traffic priority changed automatically (since they're just normal bridges), which could cause dwarves to pathfind normally through dangerous minecart entrances in your fort's walls if you're not careful.

The only <s>fool</s>''dwarf''-proof method is to make the tracks inaccessible. There are several ways to create a track which works for minecarts but doesn't allow creature-traversal; the simplest is perhaps building a [[statue]] on the tracks. Other options include adding single-tile holes (minecarts moving at reasonable speed will jump the gap), vertical drops, minecart-triggered doors, small pools of liquid (4/7 water or 2/7 magma), and hostile creatures overlooking the tracks. For safety, both ends of the track should be isolated, making the dangerous center sections completely inaccessible (though maintenance access can be provided by a locked door).

Danger does not always involve living victims: careless route designation can also result in minecarts careening off tracks or colliding with each other. If this occurs, the [[item]]s may be scattered; this can cause even more hauling jobs than the minecart aimed to eliminate. Even <s>better</s> worse, scattered items, especially [[weapon]]s, can injure passing [[dwarf|dwarves]] or other [[creature]]s; in the words of Toady One the Great, "Accidental grapeshotting of the dining room should be possible now."

Of course, the danger of using minecarts means they can also be [[Trap_design#Minecarts|used as weapons]] by imaginative players.

== Advanced usage and automation ==
Minecart-specific effects are implemented via track stops, rollers and [[pressure plate]]s with "track" condition set. Since all three are considered [[building]]s, they can't be built on the same square (however convenient track stop + pressure plate would be) nor a simple ramp, and are removed by {{k|q}} {{k|x}}.

=== More on Track stop ===
Track stops are constructions that allow further automation of minecart systems via adjustable features such as braking by friction and automatic dumping of contents. They can be built from logs, bars and blocks through {{K|b}} {{K|C}} {{K|S}}; friction amount, dumping toggle and dumping direction must be set '''before''' construction, and these settings can be neither changed nor seen thereafter; however, track stops can be linked to [[pressure plate]]s or [[lever]]s to toggle friction and dumping On or Off (trigger state is inverted: switch On = track stop Off).

If a [[stockpile]] is placed on the tile that a track stop is set to dump to, it can act as a [[Exploit#Quantum_stockpiles|quantum stockpile]] and any items dumped from a minecart that match the storage settings of the stockpile will remain there and accumulate. Normally trackstops are built on top of existing track to operate on moving minecarts, but they can also be used without tracks to create [[Exploit#The_Minecart_Stop|automatic quantum stockpiles]] (see also [[#Step-by-step_tutorial|step-by-step tutorial]]). It is not always desirable to collect ALL of certain items into one quantum stockpile, such as when distributing a material to multiple separate industries. You can link your quantum stockpile to various other stockpiles, ensuring that your dwarves will keep them supplied as necessary. Because quantum stockpiles never fill up like regular stockpiles, it may be a good idea to add a switch to turn them off.

Items dumped from a minecart at a track stop (or dumped by any other means) into open space fall through z-levels until they land on a solid surface. Items falling onto a designated [[stockpile]] will automatically be considered part of that stockpile, even if the stockpile is set to disallow those items (they will, however, be automatically moved to a more appropriate stockpile, if available). Items falling on top of a minecart will '''not''' fall "inside" the minecart. Use with caution; dwarves have fragile skulls.{{bug|5945}}

=== Automated propulsion ===
==== Roller ====
{{Main|Roller}}

A '''roller''' is a [[power]]ed [[machine component]] for the automated propulsion of minecarts. They are built over the top of existing tracks with {{K|b|M|r}}, requiring a [[mechanic]], ''(length/4)+1'' [[mechanism]]s and a [[rope]]. Rollers may also be placed directly on ramps to help pull carts up Z levels. Rollers are very useful to maintain a cart's momentum along long routes, to get them to climb Z-levels without dwarfpower involved, and to get them to reach speeds unattainable by guiding dwarves. These devices are variable-length (1-10), variable-direction and variable-speed ([[Minecart#Numbers_behind_the_scene|see below]]), all traits that can be set at construction time; a roller uses two units of power per tile it is long.

Single-tile rollers transfer power in all four cardinal directions, while other rollers generally only transfer power perpendicular to their activity direction. Longer rollers can also transfer power along their activity direction if built in the correct order, although this can be hard to accomplish and is easily broken. Rollers cannot be powered from above.

Rollers have great acceleration and capped speed. Carts going faster than the roller are unaffected. If a cart moves across an active roller in the direction the roller works and moves slower than the roller's specified speed, the cart will be set to the roller's speed. A cart going against a roller's movement direction will be sent back the way it came (once again at the roller's speed), unless it was moving extremely fast: speed increment of 100000 allows to reverse carts from the full "highest" (50000) speed roller to full "highest" speed back, but ramps can accelerate a cart beyond this. {{cite forum|144328/5702453}}
A cart crossing over a roller perpendicular to its current movement direction will gain the roller's amount of speed in the perpendicular direction without directly changing its forward motion. Without an adjacent wall to constrict its movement, this will typically send a cart off the rails on a diagonal path, completely unable to follow any tracks until it collides with a wall or is otherwise brought to rest. However, if the roller is placed over a track turn and pushes ''from'' the direction of that turn's track, the turn affects carts ''after'' the roller, so they will be forced into the turn rather than derailed in a diagonal direction. {{cite forum|144328/5702453}}

{{diagram|spaces=yes|\
tracks: full:
║ ║
═╗═ ═╢═
║ ║

╢ : roller pushing from W to E
}}
If the roller is powered, carts from ''all'' directions (unless too fast) exit S, because speed imparted by the roller forces carts toward E and ''then'' into the turn.
If not powered, carts from W and N exit S, carts from E and S exit W. Carts above derail speed will ignore the turn, of course.

{{diagram|spaces=yes|\
║ ║
═╗═ ═╟═
║ ║

╟ : Roller pushing from E to W
}}
Carts from the E or W: exit W.
Carts from N: derailed diagonally, exit SW.
Carts from S: derailed diagonally, exit NW.

Rollers affects carts on a track - if placed on a floor or ramp without any tracks, they are ignored. Depowered rollers are also ignored, friction is determined by the tiles underneath.

Because of their one-way nature, rollers are unsuitable for most two-way minecart tracks (unless you set gears toggling roller A->B off while toggling A<-B rollers on). However, a minecart set to be ''guided'' is not affected by rollers at all{{cite forum|109460/3286235}} — this allows a one-way track to be used in both directions. In addition, unpowered rollers do not affect minecarts.

Care must be taken in [[glacier]]s and other extremely cold [[biome]]s, since rollers (and the machinery used to power them) will not operate when constructed on natural [[ice]] floors.

==== Impulse ramps ====
Carts can be given momentum without rollers or changing z-level through a phenomenon called "impulse ramps". A track ramp which is connected both to a wall and to a floor will ''always'' accelerate a cart towards the connected floor tile, no matter where the cart enters the tile from. This means carts can be accelerated as though dropping z-levels, even if the cart doesn't actually change z-level at all. If a track ramp faces three directions such as ╩, then two of those directions need to be facing walls for the cart to be accelerated towards the remaining direction.

Example of straight impulse acceleration:

{{diagram|spaces=yes|\
▒▒▒▒▒▒▒▒▒▒ ▒▒▒▒▒▒▒▒▒▒
═▲▲▲▲▲▲▲▲▲▲═ ═╚╚╚╚╚╚╚╚╚╚═
▒ : Wall
═ : Normal track
▲/╚ : N/E Track/Ramp
}}

If a cart enters from the left, it will speed up on every track/ramp and exit to the right going very very fast - more than one tile every step. If it enters from the right then it will bounce back impulsed by the ramp if it's going slow enough.

As another oddity, carts coming from ramps will in some cases "teleport" through most of the next tile. This is called the "checkpoint effect", and is explained in detail in the Physics section, below. This negates the deceleration of the next tile if it is a ramp "angled" in a different direction. You can just make an upward spiral alternating impulse ramps and regular upward ramps. It takes no power, is quick and cheap to build, requiring only channeling and track carving, and the cart goes up fast, but not so fast that it launches its contents.

Example of an impulse elevator:

{{diagram|spaces=yes|\
z +0 z +1 z +2 z +3
░░░░░ ░░░░░ ░░░░░ ░░░░░
░╔░░░ ░▼╚╗░ ░░▼▼░ ░░░░░
░╝░░░ ░▼░░░ ░░░╔░ ░░░▼░
░▼▼░░ ░░░░░ ░░░╝░ ░╚╗▼░
░░░░░ ░░░░░ ░░░░░ ░░░░░

░ : Wall
╔,╚,╗,╝ : Track/Ramp
▼ : Down Ramp (empty space)
}}

Note that this impulse elevator, due to the checkpoint effect and upward curved ramp effect, will not actually result in carts traveling straight up the ramp. They will lose speed, bounce off a ramp, then be accelerated back into the spiral after a 9-turn delay on both tiles on the floor where they are stopped. This is because the checkpoint effect allows carts to travel up the ramps in a single turn, but also prevents the impulse ramps from adding acceleration unless the cart is slowed to staying on the ramp for more than one turn. Initial acceleration will carry the cart up a variable number of floors before this effect occurs, but this bouncing back and forth will occur every 5 z-levels after the first time the cart stops. When the cart ''is'' traveling upwards, it will pass every tile at a rate of one tile per turn regardless of its actual speed, due to the checkpoint effect. In tracks with only a single cart, this is negligible, but when multiple carts are on the same track (such as when you place multiple carts on a magma cart lift) this can cause collisions which derail carts or cause other unexpected or undesired behaviors.

The following impulse ramp (while larger) should alleviate these problems by using a straight ramp to go upwards, preceded by an impulse ramp to exploit the checkpoint effect and negate up ramp costs. Corners still decelerate carts, so the cart will tend towards a velocity of 72k, which is derail speed. Derail speed breaks (see Controlling Speed, below) may be necessary at the top.

{{diagram|spaces=yes|\
z +0 z +1 z +2 z +3
░░░░░░ ░░░░░░ ░░░░░░ ░░░░░░
░░░░░░ ░╔╔═░░ ░░▼▼╗░ ░░░░░░
░║░░░░ ░▼░░░░ ░░░░╗░ ░░░░▼░
░╚░░░░ ░▼░░░░ ░░░░║░ ░░░░▼░
░╚▼▼░░ ░░░░░░ ░░░░░░ ░░═╝╝░
░░░░░░ ░░░░░░ ░░░░░░ ░░░░░░

░ : Wall
║,═,╔,╚,╗,╝ : Track/Ramp
▼ : Down Ramp (empty space)
}}

Also, if you want to have a cart following a below-derail speed, the following track works well:
{{diagram|spaces=yes|\
z +0 z +1 z +2 z +3
░░░░░ ░░░░░ ░░░░░ ░░░░░
░░░░░ ░══░░ ░▼▼║░ ░░░▼░
░║░░░ ░▼░░░ ░░░║░ ░░░▼░
░║▼▼░ ░▼░░░ ░░░░░ ░░══░
░░░░░ ░░░░░ ░░░░░ ░░░░░

░ : Wall
║,═ : Track/Ramp
▼ : Down Ramp (empty space)
}}
In this elevator, the cart collides with the walls in the corners, but then realigns on the ramp, picks up speed, checkpoints through the next ramp, and slams into the next wall. It is slower (10 ticks per floor) but produces reliable speeds, and will exit the impulse elevator at little more than push speeds.

A sort of opposite effect to impulse ramps also exists: ramps lacking the proper "up" and "down" connections are treated as flat track, even if they actually go up or down z-levels. This allows building "anti-impulse" slopes consisting entirely of ramps only connected up, which a minecart can travel up forty levels and more, needing no more than a single push.

=== Controlling traffic ===

==== Switching ====

As constructions or tile features, [[door]]s and other furniture can be built on tracks. A [[door]] or [[floodgate]] can be turned on or off by a [[lever]], effectively controlling the flow of automated minecarts. This may be <s>dangerous</s> [[fun]], however.
{{diagram|spaces=yes|\
->
A ════┤≡════ B
┤ : roller pushing to East
≡ : door
}}
The roller pushes the cart east, but until the "departure condition" is fulfilled, the door remains closed and blocks the path.

[[Bridge]]s can also act as tracks, but only if they're lowered or not retracted. This property can enable levers to turn tracks on and off. However, care should be taken to ensure that such bridges are never operated while a cart is on top of them, as the cart will be flung off the track. It's worth noting that it's often faster, and cheaper, to construct large bridges than long sections of constructed track.

A powered track switch can be constructed by building an "inverted" corner as illustrated below.
{{diagram|spaces=yes|\
B B
║ -> ║
║ ║
════╚═══ ════├════
A C A C
├ : roller pushing to West.
}}

If the cart is pushed East from the stop at 'A' while the roller is activated, it will arrive at 'B'. If the roller is not running, it will arrive at 'C'. The switch works by the roller first reversing the incoming cart's movement and the cart ''then'' following the track corner.

This switch is very reliable, reacts instantly to on/off signals, and carts of any speed can be switched by this design, although very fast carts will require rollers that are several tiles long, up to three. The requirement for power can be inconvenient or impractical. Non-powered solutions may use controlled derailment, or a connecting bridge.
{{diagram|spaces=yes|\
B ╥
║
║
╞════╝ ════╡
A D C
}}
Here the track between A and C is not continuous. The only continuous track is A->B, with a corner (not a T section). Fast moving carts will tend to derail at D and rejoin the track to C. Placing a door at D will prevent the derailment, so the cart continues to B. The door is operated by mechanisms elsewhere (typically, a lever, but some fun can be had with pressure plates).

Since it depends on derailing, this switch requires a very fast cart, faster than what can be achieved with rollers alone. To gain sufficient speed, a cart must be accelerated further, usually by descending several levels or through impulse ramps. The high speed makes the cart much more dangerous and harder to control.

If carts are moving too slowly to derail at the corner, a retractable bridge may be used as a connector between A and C.
{{diagram|spaces=yes|\
B╥
║
║
A╞════bbb════╡C
}}
The bridge must overlap the corner. Bridges behave like a track crossing, allowing carts to pass in a straight line. When retracted, the corner reappears, so the carts will continue to B. Bridges take 100 steps to react to a signal, necessitating rather long "lead times" when switching tracks via bridge.

As mentioned above, special care must be taken to make sure the bridge doesn't change state while the cart is passing over it. Retracting bridges will throw the cart, causing it to stop dead. Raising bridges can even crush the cart.

==== Controlling Speed ====


Minecarts can reach extremely high speeds, especially when descending multiple Z-levels. A minecart will derail at a track corner if its speed exceeds 0.5 t/st (tiles per step), '''unless''' the route in the direction of travel is blocked:

Will derail at > 0.5 t/st:

{{diagram|spaces=yes|\
in ══╗ -> derailing
║
out
}}

Will not derail at > 0.5 t/st:
{{diagram|spaces=yes|\
in ══╗O
║
out

O : wall/column.
}}

This behavior can be used to build a "speed limiter", that will ensure that when a minecart exits it is traveling below derail speed:
{{diagram|spaces=yes|\
░░░░ ░░░░░ ░░░░░
in ═╔═╗░ ░╔S╗░ ░╔S╗░
out ═╬═╝░ out ═╗═╝░ out ═╗═╝░
░╚S╝░ ░╚═╝═ in ░╚S╝░
░░░░░ ░░░░ ║░░░
in
░ : wall
S : Track Stop (High Friction or lower)
}}
If the minecart is traveling below derailment speed, it will not be affected; if above, will be slowed down and checked again. Granted, you could do the same just with track turns, but it may take a lot of turns and time.

Since all the derailings, bounces and ramps can impart a sideway component of speed small enough to start visible drift many tiles away (say, [[Fun|in the middle of a bridge]]), track turns have one more use: forcing the carts to move strictly along the grid directions. Carts passing a turn below derailing speed convert one component of velocity into another, thus eliminating the drift.

=== Loading liquids ===
[[Water]] and [[magma]] can also be loaded into minecarts by submerging them to a depth of at least 6/7 while standing still or moving at speeds of at most 10000. Loading fluids onto minecarts can be difficult because the added friction provided by fluids can stop a cart in a submerged tile. Curiously, filling a minecart with magma does not injure a dwarf ''riding'' it. A minecart will hold enough fluid to increase the depth of a single tile by 2. This amount is listed as 833 units, which weigh 459Γ (water) or 999Γ (magma). An iron or steel cart filled with magma weighs 1313Γ, while an adamantine cart filled with magma weighs 1007Γ. Since you need a minecart above the liquid's level, possible arrangements may include pressure-activated sluices, rollers (with magma-safe chains for magma), pouring from above to "submerge" it briefly on the same level and drain excess away (dig deeper and leave a vaporizer, though if you could have power for rollers, may as well use a pump) and exploits with ramps (not necessarily impulse ramps, "same height" passing dip does it).
The liquids can be dumped by a constructed track stop.

== Quirks ==
This little quirk concerns dwarf-managed minecarts. If a track which was previously open becomes blocked (ex. flipping a switch connected to a floodgate you've built on the track to raise it) and the conditions for departure are met, instead of refusing to ride/guide the minecart or ride/guide it until it reaches the obstacle, the dwarf will pick up the minecart off the tracks and haul it to its scheduled destination on foot. If the distance is long enough and the weight of the cart heavy enough (due to being filled with heavy items such as stones), the dwarf may drop the cart because of fatigue/hunger/thirst before reaching the destination. This will cancel that vehicle setting job and make another dwarf come by and attempt to haul the cart to the nearest appropriate stockpile where another dwarf will pick up the cart and attempt to haul it to its initial stop. If the stockpile is far enough from initial stop, this second dwarf who is attempting to place the minecart on its tracks may also drop the minecart out of fatigue/hunger/thirst creating a loop that will go on until a dwarf with enough endurance manages to place the minecart where it belongs.

In fact, it seems dwarves are more than happy to attempt to carry a minecart from one stop to another even if just waiting until the track is open again would be the more sane option.

Dwarves will also carry a minecart to its next stop if the direction specified is incorrect (or invalid). This can often occur when using the default departure settings and forgetting to set the direction of each condition.

Dwarves can admire buildings while riding mine carts. Dwarves will not fall asleep during a ride (at least not from being drowsy). If riding on a continuous powered track loop, the dwarf will die of dehydration/starvation as they can not jump off to get sustenance{{cite forum|109460/3377228}}. Dwarves riding in submerged minecarts will gain experience in [[swimming]].{{cite forum|129889}}

Tracks block wagon access to trade depots, unless they're on a ramp. [[Bridge]]s can also be used, as they function as tracks but do not block wagons.

== Physics ==


Minecart physics depend greatly on the departure mode set in the route stop conditions.

When set to "Push" or "Ride", minecarts will move according to the regular laws of momentum, gaining speed when going downhill, losing it slowly due to friction when on a flat plane, and more quickly when going uphill. In these modes, minecarts will move in a straight line until they either are brought to a stop by friction or an obstacle, or until they encounter a turn. A minecart will roll straight past "blocked" ends of T-junctions or track ends, they have no power to restrict a cart's movement. The cart's behavior is largely independent of the weight of its contents (including fluids and dwarves): heavily loaded carts gain more momentum when accelerating, but this only plays a role in collisions: a heavy cart gains just as much speed and is as easy to stop as a light one. In either case, dwarves can not push nor ride an unpowered cart up a ramp, bouncing back the direction it came. At best, this is a waste of time; at worst, it will give your cart-pushing dwarf a [[fun|fun surprise]]. To solve this, the player can either use Rollers (see below) or set the cart to be Guided.

The difference between "Push" and "Ride" is whether the dwarf will go along with the cart or not.
{{DFtext|Push}}: the dwarf will give the cart an initial push, not enough to go up a ramp, but enough to go some way along flat track, and the dwarf will remain at the first stop, ready for a new job.
{{DFtext|Ride}}: the dwarf will give the cart the same initial push and then hop aboard the cart riding with it to the next stop.
{{DFtext|Guide}}: minecarts seem to ignore all laws of physics. That is:
*Ignore the weight of any and all items inside. Therefore:
**Move at the speed of the dwarf that is guiding them. It is thus recommended to pick the most [[attribute#Agility|agile]] of your dwarves for cart-guiding tasks.
*Ignore working rollers.
*Will ''not'' collide with other guided carts even when a full frontal collision would be expected.
*Will go up ramps like nobody's business.
This is therefore the recommended method of transport for simple non-powered rail systems, despite it diverting a dwarf from other, potentially more important tasks.

Some samples with behavior:
{{diagram|spaces=yes|\
A <-> B A <-> C A <-> B
B B B
║ ║ ║
A══╝ A══╩══C A══╬╗
You can only go A->B ╚╝
Works when the cart Works
is in Guide mode.
}}
In the second example above, a cart "pushed" from B will go over the junction and roll off into the unknown south.

=== Numbers behind the scene ===

According to early research by '''expwnent'''{{cite forum|112831/3536975}}:

The minecart has 3 variables for velocity. Velocity can be thought of as tiles per 100000 ticks, so a velocity of one hundred thousand means a cart travels one tile per tick. By going down a large number of ramps, a maximum velocity of 270,000 can be reached, which presents the limit for most practical applications. Short bursts of (much) higher speeds are possible through carefully planned collisions of high-speed carts {{cite forum|137557/5145499}}. (See [[#Perfectly Elastic Collisions|Perfectly Elastic Collisions]].)

Every tick the cart adjusts sub-tile position units by the amount of their velocity, as well as adjusts velocity depending on current tile (speed is reduced by the "friction" of the tile, or accelerated if going "down" a ramp). On flat (non-ramp) tiles, the cart will move to the next tile when the sub-tile position goes either above 100,000 or below 0, (or several tiles if velocity is over 100,000,) and 100,000 is either added or subtracted to sub-tile position to restart the count to the next tile change.

Since most deceleration and acceleration is applied per step, with the notable exception of corners, a cart going at twice the speed of another one can cover about four times the distance in a straight line, but only twice the distance along a winding track with very many corners.

A push will teleport a cart to the beginning of the next tile (NOT the middle!) in one tick with 19990 speed (10 speed is lost due to track friction), while a roller will give a cart the roller's set speed, and it will start to accumulate regular track friction past the middle of the roller tile. Some track features will affect a minecart when it is past the middle of the previous tile: entering a ramp or a hole/drop will happen when the cart has left the middle of the previous tile, and the ramp will gain additional distance unit depending on the leftover units from the previous tile. When a cart leaves a ramp it will emerge after one tick in the middle of the next regular tile, so its entry coordinate is "50000-speed+friction". Rollers also affect the speed of minecart from the middle of the previous tile.

Friction of tiles:
{| class="wikitable"
|-
! Tile
! Friction
! Comment
|-
| Tracks
| 10
|-
| Ground/Floor
| 200
|-
| Unusable ramp
| 10
|-
| Upwards ramp
| 4910 (10+4900)
|-
| Downwards ramp
| -4890 (10-4900)
|-
| Roller
| ±100000 (but capped by the set speed)
|-
| Corner track
| 10
| Speed reduced by 1000 upon leaving the corner tile
|-
| Track stop (highest)
| 50000
|-
| Track stop (high)
| 10000
|-
| Track stop (medium)
| 500
|-
| Track stop (low)
| 50
|-
| Track stop (lowest)
| 10
|-
| Water 1-6
| Additional (WaterLevel - 1) * 100
| rowspan="2" | [[#Skipping|See Skipping]]
|-
| Magma 1-6
| Additional (WaterLevel - 1) * 500
|-
| Empty space
| 0
|}

Water of depth 7/7 provides a friction of about 10000 per step, as does maximum-depth magma. This higher friction may not apply to very slow-moving carts.

Impulse sources:
{| class="wikitable"
|-
! Feature
! Speed
|-
| Push
| 20000
|-
| Roller lowest
| 10000
|-
| Roller low
| 20000
|-
| Roller medium
| 30000
|-
| Roller high
| 40000
|-
| Roller Highest
| 50000
|-
|}

Note, again, that nearly all of these values are applied ''per tick'', rather than ''per tile''. The exceptions are curves, which is 1k deceleration per direction change at the half-way point of the tile, and rollers, which ''set'' the speed every tick. This makes rollers particularly useful in high-deceleration situations, such as underwater, but require that ''nearly every tile'' in such high-deceleration situations have a roller.

A cart heading up a ramp can experience deceleration on multiple ticks, (and stays on the tile more ticks the slower it is going, resulting in greater deceleration,) and as such, a cart leaving a "Highest Speed" roller with 50k velocity will not be able to climb 10 consecutive straight ramps, since they are ''not'' "5k deceleration each". In fact, the first ramp not on a roller will be -15k velocity, and, depending slightly upon other factors of "remainder" x position, the second may completely cancel forward momentum, and send it rolling back down, where it will bounce off the roller repeatedly. Using rollers to power carts up ramps reliably requires rollers every other un-rollered ramp. Fortunately, rollers can be built upon ramps, themselves, which allows for rollers to only need to be built every other floor. (Exploiting the [[#Checkpoint Effect|checkpoint effect]] can allow one to bypass this requirement.)

=== Sub-tile Positions and Velocity ===
Carts store six values that are unique to them. Three sub-tile position values, and three velocity values. (X, Y, and Z.)

Note that the Z position and velocity only matter when a cart is in flight. (See [[#Falling|Falling]] and [[#Cart Jumps|Cart Jumps]].)

Each non-ramp tile is functionally composed of a value between 0 and 100,000, with a "centered" cart sitting at the 50,000 point in all three directions. When a cart has velocity, it is added or subtracted from the current position every tick, and then a friction force is applied to the cart.

In essence, every sub-tile position unit is a decimal value of a tile, 0.000001 tiles, in a game that largely prefers integer values.

When carts move beyond the maximum or minimum value of a tile, they physically move a tile on the map, and start at the far end of the sub-tile position the next tile. (I.E., traveling West, a cart that starts a tick at 15,000 X sub-tile position and has an X velocity of -20,000 would move to -5000 X sub-tile position, which is out of bounds for that tile. As such, it will travel one tile West, and start the next tick at 95,000 X sub-tile position. It will also lose 10 velocity in that tick due to friction with the track if it is on a track, or 100 velocity if it is on regular ground, or no velocity if it is airborne.)

Ramp tiles are longer, approximately 144,000 in the direction where it "slants downward", (to approximate a 45 degree slope, it is square root of two times longer,) and centered at 72,000. Because of this, a cart with no velocity dropped from a hatch will land at the center of a tile, at position 72,000, and 72,000, and will start rolling in the ramp's "downward" direction, picking up the ramp's acceleration (4890 per tick in the direction of the ramp's "downward" direction) every single tick, then moving that sub-tile amount every tick. (This results in a cart that takes 5 ticks of acceleration to leave its ramp - 6 ticks overall - and to leave the ramp with about 23k velocity, slightly more than a push.) When it enters another ramp ''facing the same direction downwards'', a cart will start at the 0 or 144,000 position, and have twice as far to travel. This means that if a cart enters a ramp from the side, it will gain twice the momentum of simply starting at the midpoint of a ramp.

Note that passing from one direction of ramp to another or to flat terrain causes unintuitive behavior, "teleporting" to the midpoint of another tile in what is called the "[[#Checkpoint Effect|checkpoint effect]]".

Note, however, that sub-tile positions are carried over from tile-to-tile. This separate tracking of velocity and position between X and Y can lead to problems with diagonal motion:

{{diagram|spaces=yes|\
z0 z-1
▒║▒ ▒▒▒
═▼═ ▒╬▒
▒ ▒ ▒║▒
▒ : Wall
═, ║ : Track
╬ : Track and Ramp
}}

If a cart is passing West-to-East over this setup, the valid ramp to the South will apply "Southward" acceleration to the cart (-Y velocity) as it passes through the ramp tile. Assuming it only spends one tick in that tile, it will still have gained about -5k Y velocity, which will still apply motion Southward. If the tracks continue straight for another 11 tiles, it will have accumulated enough Southward motion to try to move a tile South, even if all tracks are facing East-West.

'''Non-curving tracks do not correct this motion'''.

They don't "tip back over" without adjustments in the track. Any value of sideways motion on tracks larger than 990 will lead to a derailment. (Lower values will be nullified by friction before they are enough to lead to derailment, but there is currently no way to apply such a small amount of velocity.)

If the tile to the South is a wall at that point, it will be considered a collision with a wall that ''halts all motion''. If the tile is open, it will generate a diagonal track derailment that will send a cart flying until it strikes a wall, at which point it will not re-rail itself. In almost any circumstance, this is undesirable behavior.

The only way to appropriately deal with this is to either cancel out this behavior with an equal amount of acceleration in the opposite direction, or to take a curve.

Note, again, that sub-track position is saved in both directions, so when a cart approaches a curve, it will already have a shorter or longer distance past the curve when it makes the turn.

Curves are applied "halfway through" a tile. If a cart is moving East, and approaches a North-East track at 20k velocity, and friction is eliminated for the purposes of a cleaner demonstration, then when it enters the tile at sub-tile point 0 X, and 50k Y at the start of a tick, it will then move 20k East (+X) the next tick, and be at 20k X sub-tile position, and 50k Y sub-tile position. Next tick, it is at 40k X sub-tile position, and 50k Y sub-tile position. The next tick would take it to 60k X, but that's past the halfway point, so it stops at 50k, turns (and thus loses 1k velocity, but translates the rest from X-velocity to Y-velocity) and travels another 10k. It is now at 50k X sub-tile position, and 60k Y sub-tile position. Next tick, it travels at 19k velocity North, and so moves to 50k X sub-tile position, and 79k Y sub-tile position. Then in two more turns, it leaves to the North.

In the case of diagonal motion due to having velocities in X and Y at the same time, it is critical that the direction the cart is heading in reaches that halfway point in a curve before the cart leaves the track off its sideways velocity direction. If it does so, all sideways velocity is lost, as forwards velocity ''overwrites'' sideways velocity in a curve. If, in that example in the paragraph above, the cart entered at 0 X sub-tile position with 20k X velocity, and 40k Y sub-tile position and -1k Y sub-tile position, it would take that "curve" (or rather, redirection of velocity) on the third turn, while it is at 38k Y sub-tile position to start with, and then move to 47k Y sub-tile position at the end of that tick. It would then move to 56k Y sub-tile position in the following turn, and take 3 turns, rather than just 2, to clear the tile.

But, most importantly, it would be centered in the X sub-tile position, and with the negligible difference of an extra tick, all sideways velocity could be safely ignored.

There are two common ways to gain sideways velocity: Rollers facing perpendicular to the cart's travel path (which, as covered above, are almost always a bad idea, as it is easier to push ''against'' the travel direction of a cart into a curve, which redirects all velocity in the new direction,) and [[#Corner Ramp Derail|corner ramps]], and require a curved track to compensate for sideways velocity within a few tiles.

=== Track Direction Irrelevance ===
Carts that are traveling independently, (that is, not guided,) only care that tracks ''are'' on the tile, not which direction the tracks actually move. Tracks respect only curves (with two exits) and ramps.

This means, for example, that the following tracks, when a (non-guided) cart travels from West-to-East, are functionally identical in effect:

{{diagram|spaces=yes|\
A════════════B A╬║╚╔╣╩╦╠╥╨╞╡B
}}

This is because so far as the cart is concerned, only valid ramps and curves with two exits where there is no exit in the path they are traveling matters.

Hence, if a minecart encounters the end of the track or a T junction with no "exit" in its movement direction, it will simply leave the track and continue on its course in a straight line until it encounters an obstacle, slows to a stop, or encounters another track even if the tile at which it joins the new track instantly sends it around a corner.

In fact, in a track designed for pushes or rides, a "║", a "╦", a "╬", and a "╥" are ''only different in appearance'', and are ignored by an unguided cart, which will continue in its current direction, regardless of the track. For any purpose but guided tracks, ''only curves and ramps matter at all''.

Tracks like T-junctions, however, ''are'' respected by dwarves guiding carts, who will lift and carry carts if they cannot find a valid track to their destination, and can choose to follow any orthogonal direction at a four-way junction in much the same way as they normally pathfind. What this functionally means is that T and four-way junctions ''only guide dwarves hauling a cart, not carts, themselves''.

Carts only check for curves when they are halfway through a tile. When they get there, they look to see if their path has no exit. (That is, if it is traveling East, it checks if there is an East exit.) If there is, it ignores all other track directions, and keeps traveling. If there is not, it checks to see if there are only two exits to the track, and if one of those directions was the direction it "came from". (That is, if traveling from the East, it checks if there is a valid exit to the West, and if so, if there is either a North exit or a South exit.) If there is not, it ignores the track anyway, and keeps on traveling as though it were still on track. If there is, it will subtract 1000 from the velocity of the cart, and redirect all forward velocity to the direction of the curve. This change in the direction of velocity ''overwrites'' any "diagonal" velocity, which can prevent diagonal velocity derailments, but any perpendicular velocity is not preserved, and is instead discarded.

=== Valid and Invalid Ramps ===
Ramps are functionally defined for cart purposes as being a tile which exerts an acceleration force upon its "downward slope", and which allows connection to tracks a z-level above or below. This downward slope requires a cart to have one ''and exactly one'' carved exit to the tile that is the "bottom" of the ramp. Ramps accelerate carts in this "downward" direction (possibly leading to [[#Corner Ramp Derail|diagonal movement]]), and the deceleration of an "uphill" ramp is actually just the acceleration being applied against the direction of a cart's movement.

This is where players can find an exploit in the behavior of ramps - if there are ''two'' "downhill" exits to a ramp (such as a "T junction" on a ramp where only one exit faces a wall), then the ramp provides no acceleration ''or'' deceleration, allowing carts to travel up ramps without any loss of momentum except for the standard "flat track" deceleration, because as far as the cart is concerned, the track ''is'' flat. (A T junction is also not a curve, so the track is considered flat and straight no matter what direction the cart is traveling.)

Similar effects can be achieved when there are ''no'' "downhill" exits to a ramp. This may be the case if you have, for example, an East-West track with a one-tile channel with a ramp in it. The cart will travel through the "dip" with no change in velocity. It can also be the case if you abuse the [[#Track Direction Irrelevance|Track Direction Irrelevance]], and set only exits ''up'' the ramp, and none leading ''down'' the ramp. For example, if a cart is traveling from West to East up a slope, only carving East exits on each tile of ramp will make the cart travel up the ramp, and then recognize the tile it is on as being a "flat" tile, thus ignoring any deceleration from traveling uphill.

Note that this effect only reliably occurs at below-derail speeds as the cart will treat the ramp as an invitation for a ramp jump otherwise. (This almost always results in a collision with a wall that will stop forward progress.)

=== Falling ===
When falling, a minecart appears to cause no damage upon collision, possibly to allow cart "stacking" across Z-levels.{{cite devlog|2012|04|06}} A dwarf riding in a minecart that is dropped multiple z-levels suffers normal fall damage. Minecarts can fall through up/down stairs.

While airborne, carts do not feel the effects of friction in any horizontal direction, and will continue until they strike an obstacle. Carts that land on tracks instantly re-rail themselves regardless of track directionality.

Falling carts accelerate similarly to the way that a ramp will accelerate a cart in a special z-only velocity that only applies to airborne carts. (Actually, acceleration due to gravity in freefall seems curiously slightly ''slower'' than ramp acceleration.) Ramp acceleration, while it logically should be partially z-directional, is only recorded as x- or y-directional, and there is no translation of z-directional velocity upon landing. Landing carts zero out their vertical velocity upon landing, even when landing on ramps, although carts that had horizontal momentum while falling preserve it.

This means a cart falling (from a hatch, thus with no horizontal speed) onto a track ramp is accelerated as if starting from the middle of the ramp - i.e. to the same speed, no matter how many Z-levels it was dropped, vertical velocity is negated. {{cite forum|144328/5701211}}

Carts falling onto a floor can, however, cause damage to creatures ''one tile below the floor''. This can be used in an [[exploit]] called a "thumper", where carts are caused to repeatedly fall on a floor above an entrance to the fort, inflicting significant damage (as though it were a collision) on those below the cart.

=== Cart Jumps ===
Carts that cross off of "up" ramps relative to their current direction of travel, which do not have a ceiling above them, are traveling above derail speed, and do not have valid ramp track before them can translate a portion of their horizontal velocity into vertical velocity, causing a cart to be projected into the air until vertical velocity is negated and overcome by the gravitational acceleration. Because downwards acceleration is applied per-tick, this creates a reasonable facsimile of the parabolic motion of an actual object rolled up a ramp and launched with significant speed.

{{diagram|spaces=yes|\
z0 z0 hiding ramps z+1 A z+1 B (hidden ramp)
▒▒▒▒▒▒▒▒▒▒▒▒ ▒▒▒▒▒▒▒▒▒▒▒▒ ▒▒▒▒▒▒▒▒▒▒▒▒ ▒▒▒▒▒▒▒▒▒▒▒▒
═▲▲▲▲▲══▲▒▲═ ═╚╚╚╚╚═══▒══ ▼▼▼▼▼ ▼═▼ ▼▼▼▼▼ ▼╚▼
▒ : Wall
═ : track
▲ : Ramp
}}
In this diagram, if there is no ceiling above it, the track in z+1 A will launch its carts airborne when they travel across the ramp. z+1 B (with a ramp on the tile on the hill) will not launch the cart. The cart would also not be launched with ''any'' valid ramp, even if it does not travel in an appropriate direction, such as North/South (which the cart will ignore, as it is not a curve, anyway, although it may produce acceleration that may cause diagonal movement.)

Carts that are traveling at derail velocity will also start "jumping" from the track if it hits an un-tracked tile, flying over and ignoring any tracks until it is ready to land. Carts that land upon tracked tiles re-rail themselves, and clever designers use this feature to jump over curved track sections in one direction or another. (Retracting bridges over untracked tiles can cause jumps or not cause jumps depending upon the status of the bridge.) Minecart speed must be carefully regulated to ensure reliability of jump length.

Hitting untracked tiles at around 70k velocity creates a vertical component to acceleration that allows for jumps of around 6 (horizontal) tiles that do not actually leave the z-level the cart is on, but which do apply z-direction velocity on the cart, as per falling.

Carts that approach a downward slope at a high enough velocity will also make a jump, (or rather, ignore the ramp and fly forwards) but will not do so if the [[#Checkpoint Effect|Checkpoint Effect]] is exploited through an impulse ramp before the actual downhill as the impulse ramp "tricks" the cart into thinking it has already started going downhill. The cart will also not fly off the ramp if there is a wall and ceiling preventing any motion but going down the ramp.

=== Skipping ===
If a minecart is moving fast enough, it can skip over [[water]] or [[magma]], making splashes of [[mist]] (or [[magma mist]]) as it attempts to move on them horizontally. This horizontal movement is independent of the minecart and its content's [[weight]].

Skipping causes significant friction on the cart, and even a cart going at max speed from ramps can only make about 50 tiles without requiring re-acceleration. (Carts that decelerate enough that they do not trigger the skipping effect will, of course, sink.)

=== Corner Ramp Derail ===

Corners on upward ramps can cause diagonal movement, forcing a derail even if the cart has a wall next to it, which will force a stop when it touches a wall that forces dwarves to manually reset the cart.

This is caused by the fact that a cart, after turning the bend in the track halfway through the length of the tile, will still "accelerate down", which is now perpendicular to the movement of the cart, causing acceleration to occur in two directions. (Down corner ramps do not have this problem, as when they pass the halfway point, all perpendicular motion is added to forward motion, and after that curve, all downward acceleration is in the forward direction.)

There are two fixes to this problem. One is to simply not put corners on up ramps. The other is to take advantage of the [[#Checkpoint Effect|Checkpoint Effect]], by making a ramp (possibly including an impulse ramp) one tile in front of the ramp to make it skip through most of the tile before sideways momentum can be built.

=== Checkpoint Effect ===
The checkpoint effect, [http://www.bay12forums.com/smf/index.php?topic=144328.0 explained in depth by Larix], is an odd and highly exploitable feature of ramps where minecarts "teleport" through the next tile of track, ignoring nearly all minecart physics (except that they stop at all walls or other obstacles and only respect curves with no backing wall and invalid ramps if they are below derail speed) and passing through that tile in just a single tick, and into the next tile at the halfway point.

This effect occurs when a cart leaves a downward ramp for any other direction of tile. (This includes ramps which accelerate in different directions, even a ramp which goes from accelerating East to accelerating North due to a bend in a chain of standard down ramps in a curve.) This allows, for example, two valid straight ramps directly next to one another with a cart dropped onto one or the other with no momentum to have the cart pick up acceleration going "down" the ramp as normal, but then flying up through the "up" ramp it travels into with no loss of momentum, as though it had come from an impulse ramp. If the two ramps had at least one space of distance between them, and then a cart were dropped in, the cart would instead "rock" back and forth between the two ramps.

This seems to be because ramps have a slightly longer length than regular tiles - 144,000, rather than 100,000 distance. When this "snaps back" after a ramp, it seems to project the cart suddenly further along the track, making it jump a tile ahead even when otherwise moving at relatively low speeds.

This [[bug]] is the cause of a ''wide array'' of unexpected behavior among people who do not take this bug into account. It causes derailments or failure to climb up seemingly valid impulse elevators. In general, it makes a system that behaves extremely counter-intuitively, and operates ''any time a cart encounters a valid ramp''. At the same time, when its effect is accounted for, it is highly exploitable: It causes "perpetual motion devices" using no power when two opposing ramps are placed next to one another, since the "uphill" effect of the opposing ramp is ignored, preventing deceleration.

Another useful thing to note about this exploit is that carts traveling at no less than 72,000 or so speed (enough to travel half a ramp tile in a single tick) can travel through every tile in just one tick at no change in velocity as long as the tiles alternate between impulse ramp or actual down ramp and any other tile type. The cart checkpoints through the non-down-ramp tiles, and can pass through the (impulse) down ramp tiles in a single tick, before they can actually start gaining momentum.

{{diagram|spaces=yes|\
▒▒▒▒▒▒▒▒▒▒ ▒▒▒▒▒▒▒▒▒▒
═▲═▲═▲═▲═▲═ ═╚═╚═╚═╚═╚═
▒ : Wall
═ : Normal track
▲/╚ : N/E Track/Ramp
}}

If the cart enters from the West at less than 72,000 speed, some of those ramps will cause Eastward acceleration.

This means that an impulse ramp not contiguous to other impulse ramps has a top speed of around 75k:

{{diagram|spaces=yes|\
▒▒▒▒▒ ▒▒▒▒▒
▒╔═╗▒ ▒╔═╗▒
▒╚▲╝▒ ▒╚╗╝▒
▒▒▒▒▒ ▒▒▒▒▒
}}
This setup makes a cart that travels clockwise at a speed that fluctuates around 75k velocity. If the cart has more than 72k velocity, it fails to accelerate in the ramp, as it leaves the ramp in a single turn due to checkpointing to the halfway point. After that, the curves sap 1k velocity, and every tick saps 10 velocity.

Two contiguous impulse ramps with a same-facing "downwards slope", however, do not suffer the checkpoint effect in the second tile, giving functionally triple the space to accelerate. This means it will add velocity (at the standard rate of 4.9k per tick) up to a maximum speed of 216k.
{{diagram|spaces=yes|\
▒▒▒▒▒▒ ▒▒▒▒▒▒
▒╔══╗▒ ▒╔══╗▒
▒╚▲▲╝▒ ▒╚╗╗╝▒
▒▒▒▒▒▒ ▒▒▒▒▒▒
}}
This example results in a cart moving three times as fast as the previous cart.

Three successive ramps results in the highest attainable speeds.

In practical terms, this means that only consecutive ramps should be used for high acceleration, but singleton ramps can be used to have speeds that are somewhat regulated.

=== Stacking ===
If a minecart lands on top of another minecart, they may form a stack, with the upper cart on the z-level above the lower. Subsequent carts do not form a stack, but rather quantum stockpile in the same space. This behaviour is useful for [[megaprojects]] and [[trap design]] with minecarts as the weaponry. Moderation should still be exercised: carts take longer to fall into a "stacking" tile already occupied by other carts and will spend that time "hanging" in the air above the stack. This can lead to following carts striking them, which can cause all kinds of malfunctions. The extra time is two game steps for every cart already in the stack, which doesn't hurt stacks of ten carts very much but makes stacks of 100+ rather impractical.

These minecarts on the upper level generally need to be struck with another minecart to move out, or have their support removed. The latter option is safest done by shooting it away with another minecart, manual removal of a stack-supporting cart typically causes the next cart from the stack to [[fun|fall on top]] of the hauler.

=== Perfectly Elastic Collisions ===
Minecart collisions are perfectly elastic, meaning that not only do minecarts not take damage, but that two carts that are rolling which have frontal collisions of near-similar speed, and where one cart is no more than twice the mass of the other cart, will result in a billiard-ball-like effect of the lighter cart bouncing off the heavier cart with a proportional speed increase dependent upon the relative momentum behind the heavier cart.

Using this trick with carts already at the 270,000 maximum speed from ramps can result in "supersonic" carts traveling at speeds in the millions (travelling a dozen tiles per tick), but where they are suddenly subject to 10,000 units of "terminal velocity" friction per tick. [http://www.bay12forums.com/smf/index.php?topic=137557.0 Thread with SCIENCE here].

While hypothetically capable of launching a minecart into orbit when used in conjunction with a ramp, no cargo can be contained in the launched cart, as the collisions will force ejections of the cargo. Your "unwilling volunteer" [[goblin]] space pioneers will simply become paste underneath the wheels of an extreme high-speed cart.

== Non-standard uses ==
Minecarts include some interesting characteristics that have motivated uses beyond hauling. They can be useful for creating fully-automated [[exploit|quantum stockpiles]] and [[garbage disposal]]s. Storing perishable goods (meat, meals, etc.) inside a minecart appears to guard against rot and vermin.
Minecarts can be [[Trap_design#Minecarts|used as weapons]], or as (hopefully non-fatal) triggers to restart stalled [[healthcare]]. They can also be used to time/control game events, either using a basic [[repeater]] or much more advanced [[minecart logic]].
Minecarts trigger [[pressure plate]]s, which means a trap can be designed to trigger when a thief attempts to steal a minecart.
A pressure plate can be used as automatic and more precise custom "launch when full enough" system - as long as weight of your minecarts stays the same. You cannot build a hatch or roller on the same tile, so launch by bumping with another cart. {{cite forum|15096/4580050}}
Dwarves riding minecarts can attack enemies within reach (which goes back to dev log). This applies to shooting, and they actually can hit targets while riding by.{{cite forum|109460/5266119}} Whether a minecart protects the rider and how it interacts with dodging is not known yet. Minecart riders can also [[Swimming#Minecart_training|train swimming]] and [[Megaprojects#Surveillance_Track|detect ambushers]].

== Adventure mode ==
In addition to being used for hauling, minecarts can also be ridden in [[adventure mode]]. (Adapted from forum thread {{cite forum|122903/4258212}})

# If the minecart is in your inventory, drop it. If it is already on the ground, proceed to step 2.
# Press {{k|u}} when you are 1 tile away from the minecart (or standing on the same tile as the minecart).
# You will be presented with the following options:
[[File:minecart adventure mode menu.png|left]]
{{clear}}
* If you {{DFtext|Push}} the minecart, it will move a few tiles in the direction you chose. Physics comes into play here, so it will gain/lose speed depending on the usual factors.
* If you {{DFtext|Ride}} the minecart, you will hop into the minecart, even if you were a tile away, and it will move in the chosen direction with you in it. It will gain/lose speed depending on the usual factors. Whilst the minecart is in motion, you should press {{k|.}} to skip your turn; if you attempt to move whilst the minecart is still in motion, the laws of physics come into play, and you will take [[wound|damage]]. Alternatively, you can push the minecart whilst it's still in motion (although it's unclear how one can bend [[physics]] so as to push a moving minecart whilst inside the minecart). If you push it in the same direction you are already travelling in, you will greatly increase the minecart's velocity. You can also push it in different directions, and this will cause it to gradually change direction-the amount of pushes this requires depends on the minecart's velocity. Once the minecart has stopped moving, you may move out of it safely, or you may want to give it another push. Note that if you push a minecart right after having ridden it (still on the same tile as the minecart), it will act as though you chose to ''ride'' it.

If you want to test this out without creating an adventurer, the [[object testing arena]] allows you to spawn minecarts ({{k|k}}-{{k|c}}-{{k|n}})

== Forging and Melting ==
* Metal minecarts cost '''two''' [[metal]] bars to forge, or '''six''' [[adamantine]] wafers.
* When a non-adamantine metal minecart is melted down, it will return '''1.8''' metal bars, for an '''efficiency of 90%'''.
* When an adamantine minecart is melted down, it will produce '''1.8''' wafers, for an '''efficiency of 30%'''.

== See also ==
* [http://www.bay12forums.com/smf/index.php?topic=109460.0 The "How Does Minecart" Thread] by '''Girlinhat''' et al.
* [http://www.bay12forums.com/smf/index.php?topic=112831.0 SCIENCE: Quantifying minecart physics] by '''Snaake''' et al.
* [http://www.bay12forums.com/smf/index.php?topic=129676.0 How to build a Multi-cart Ore to Magma Minecart Project without needing power] by '''WanderingKid'''.
* [http://www.bay12forums.com/smf/index.php?topic=144328.0 My very own Minecart Education Thread. Ten Lessons, now complete.] by '''Larix'''.

== Bugs ==
*A dwarf will drop her [[child|baby]], if she has one, when boarding a minecart set to be ridden.
*Dwarves have no concept of traffic safety and will walk into busy minecart lines to retrieve objects, often with deadly consequences. This is especially problematic in [[Swimming#Minecart_training|clever applications]] depending on dwarves riding the carts very frequently, because they have a bad habit of dumping their worn clothes on the tracks after a minecart ride. Adding an automatically-operated [[hatch cover]] at the end of such a ride can help prevent [[unfortunate accident]]s.
*Dwarves cannot guide a minecart through an unlocked door unless another dwarf opens the door.{{bug|6056}}
*It is possible for a creature and minecart moving towards each other to pass without collision if they exchange tiles in the same tick.
*After a minecart ride, a dwarf will sometimes haul the minecart to a storage stockpile, leaving another dwarf to haul the vehicle back to the route.
*Minecarts falling onto a floor injure creatures in the tile below the floor.{{bug|6068}}
*A minecart's initial velocity is not affected by weight, when pushed or launched from rollers.{{bug|6296}}
*Removing a stop that has a vehicle waiting on it may cause the game to crash.{{bug|5980}}

{{Category|Fortress mode}}
{{Category|Interface}}

[[ru:Minecart]]

Minecart

2015-06-21T03:18:33Z

NW Kohaku: /* Physics */ Moving "Numbers Behind The Scenes" up front because it contains information necessary for explaining other subsections

{{Quality|Masterwork|08:15, 19 May 2015 (UTC)}}
{{av}}
A '''minecart''' is a [[tool]] intended for [[hauling]], introduced in version 0.34.08. It can be made of [[wood]] at a [[carpenter's workshop]] or [[metal]] at a [[metalsmith's forge]] (using the [[Metal crafter|metalcrafting]] labor.) Minecarts store up to five times as many items as [[wheelbarrow]]s and are quite a bit faster than dwarves hauling objects by hand, but have the disadvantages of requiring a dedicated track network, a complex route planning phase, and the possibility of dwarves [[Fun|blundering into the path of carts filled with lead ore]]. Tracks may be carved into stone, or [[Construction|constructed]]; the latter allows above-ground routes, but these are more difficult to set up due to their additional [[building material|material requirements]].

Just like wheelbarrows, minecarts are considered [[item]]s and are stored in a [[furniture]] [[stockpile]]. Despite their five-times-greater capacity, they are only 33% larger than wheelbarrows and are identical in base [[item value|value]] when made from the same [[material]] (the value may differ due to the [[item quality]]). [[thief|Thieves]] or even mischievous animals can steal minecarts, even when they are moving on a track{{cite forum|109460/3289070}}. However, minecarts moving fast enough or being ridden cannot be stolen.

Although most of the utility of minecarts is in [[fortress mode]], an [[adventure mode|adventurer]] can also ride in a minecart. Adventurers can also pick up and relocate minecarts.

The invention of minecarts revolutionized the [[minecart logic|Science of Dwarfputing]] by enabling smaller, faster logic systems to be built.

== Basic Minecart Usage ==
Minecarts can be used to swiftly transport dwarves, [[flow|fluids]], and/or large amounts of items, but before you have a functional minecart there are several preconditions that need to be met. First of all you need an actual minecart, constructed either in a [[carpenter's workshop]] or [[metalsmith's forge]]. For the minecart to be able to move you also need to carve (with {{k|d}} {{k|T}}) or construct (with {{k|b}} {{k|C}} {{k|T}}) a track, which could be as simple as a straight line. Finally you need to construct stops on your track (with {{k|b}} {{k|C}} {{k|S}}) where the minecart will start and stop.

After you have created the stops and assigned a cart to the track, you must create logic routes connecting several stops and designate starting conditions for each stop. This is done with the {{k|h}}auling key. The most basic conditions are how the cart's movement is initiated and in which direction the cart should start moving. Carts can be either be Pushed (a dwarf stands at a stop and gives the cart a single push) or Guided (a dwarf continually pushes the cart forward, guiding it along the track). The [[hauling]] [[labor]] required for pushing and guiding carts is called "Push/Haul Vehicles" and is turned on by default.

To control which items to transport you can add conditions specifying: (1) which kind of items to be loaded, and unloaded, (2) stockpile links to define which stockpile(s) the items should be un/loaded to and from.

===Capacity and weights ===
Minecarts have five times the [[Weight|capacity]] of [[wheelbarrow]]s.

'''Examples of the capacity of one cart'''
{| class="wikitable"
|-
! Item
! Amount
|-
| [[stone]]
| 5
|-
| [[wood|log]]
| 10
|-
| [[block]]/[[bar]]
| 83
|-
| [[Kitchen|prepared meals]]
| 500
|-
| [[Trap_component#Spiked_ball|spiked balls]]
| 500
|-
| [[Weapon#Native_weapons|mace]]
| 625
|-
| [[Weapon#Native_weapons|spears]]
| 1250
|-
| [[cloth]]
| 2500
|}

The weight of the loaded minecart does not affect the initial velocity received from pushing or launching from a roller. However, the load of a minecart ''does'' affect whether a [[pressure plate]] triggers or not, based on the pressure plate's setting.

'''Weights of different carts'''

{| class="wikitable"
|-
! Type of cart
! Empty cart
! Fully loaded (items)
|-
| oaken minecart
| 28Γ
| 378Γ (10 oak logs)
|-
| platinum minecart
| 856Γ
| 10482Γ (83 gold bars)
|}

The weight of a minecart is one twenty-fifth (1/25) the [[density]] of its material in Urists. Because pressure plates can be set to trigger at intervals of 50 Urists, minecarts with weights just under a multiple of 50 are ideal for switching based on whether they're full or empty. The best minecart materials for full/empty switching are as follows:

{| class="wikitable sortable"
|-
! Material !! Minecart weight !! Content weight required to trigger !! Banana roasts required to trigger (for scale)
|-
| [[Bismuth]] (moods only) || 391 || 9 || 15
|-
| [[Brass]] || 342 || 8 || 14
|-
| [[Electrum]] || 596 || 4 || 7
|-
| [[Fine pewter]] || 291 || 9 || 15
|-
| [[Glumprong]] || 48 || 2 || 4
|-
| [[Lay pewter]] || 291 || 9 || 15
|-
| [[Nickel silver]] || 346 || 4 || 7
|-
| [[Tin]] || 291 || 9 || 15
|-
| [[Trifle pewter]] || 291 || 9 || 15
|}

=== Creating tracks ===
Minecart tracks are made up of contiguous track, tracked ramp, or bridge tiles. Track tiles and tracked ramp tiles have a direction or series of directions associated with them. These directions dictate which directions a minecart on a given tile may move from that tile. For example, a Track NE (northeast) tile allows a minecart on it to move either north or east from its present position. Therefore, if you want your minecart to move east along a straight piece of track, then return west using that same track, you would need to use EW tracks so that the cart could travel east initially, then return west over the same track. Excluding designs in which the cart will "jump" tracks via a drop or other ramp, tracks must be valid end to end to work for most looped or straight-track applications. A single east only track tile in your line of east-west tracks will cause any route using the track to fail the moment it tries to go the wrong way over that tile. Minecart tracks can be built in two ways: Engraved/carved or constructed. A given minecart track need not use engraved or constructed elements exclusively, as the two methods can be used interchangeably depending on the needs of a given section of track. The way the tracks are built is slightly different between the two, as explained below.

====Simple tracks====

'''Carved'''

A single-tile wide strip of natural stone can be designated to be [[Engraver|carved]] (with {{K|d}} {{k|T}}), which will create a straight two-way track. The creation of corners, crossings, and T-junctions is as simple as designating another strip of track that overlaps an existent or newly designated track. Engraved tracks are removed by [[smoothing]] the rock they're on, which results in a smooth floor (that can be re-engraved if necessary), or by building a [[floor]] on top and subsequently removing it. Dwarves can carve corner tracks in one pass by designating the track carving twice and canceling unwanted carvings (with {{K|d}} {{K|x}}). Tracks can be engraved in any natural floor tile, rough, smooth and even over engravings, providing an easy method to remove low-quality or undesired floor engravings. Once a track has been engraved, it's important to check the track directions for each tile in the route carefully to make sure no mistakes were made by yourself or the game's track engraving logic.

'''Constructed'''

Tracks can also be built as regular [[construction]]s (through {{K|b}} {{K|C}} {{K|T}}). This method is resource-expensive, since each track tile requires one stone, [[bar]], or [[block]] for construction, and time-consuming, since you can't designate strips longer than 10 tiles at a time. Corners, crossings, T-junctions, and ramps also have to be designated individually. However, it is usually the only way to build tracks above ground or on soil (barring the [[Obsidian farming|creation of obsidian]]). Constructed tracks are designated for removal like any regular construction; be aware that removing track ramps built on top of natural ones will also remove the original ramp, leaving a flat floor.

====Ramps====

'''Carved'''

The carving of natural ramps is a little more confusing: to carve a two-way track on a ramp (natural only, does not work on constructed ramps), you must designate the track '''starting on the ramp and one square beyond''' in the direction you want the track to go. For the side of the ramp square you want to head upward, there '''must''' be either a natural or constructed wall in the square next to it, otherwise the game assumes you are trying to carve it on the same level -- this can result in the track being carved underneath a door or other object. If you have accidentally done this, you can correct it by smoothing the ramp and constructing a single square of wall next to it, then re-carving the ramp correctly. (However, the wall must stay there permanently; removing it will disconnect the track.)

'''Constructed'''

When constructing track ramps, the stated direction should be the same as the connected tracks. For example, a track going up from West to East would require, starting from the West, a Track (EW), a Track/Ramp (EW) and a Wall behind the ramp, underneath the section of track above it. Incorrectly placed ramps result in minecarts ignoring the ramp and crashing into the supporting wall. They will not, however, display as unusable as when the supporting wall is missing.

'''Examples of ramps'''

A simple ramp would look like this:
{{diagram|spaces=yes|\
z +0 z +1
░░░░ ░░░░
═▲o ░▼═
░░░░ ░░░░
o : wall
}}

Carving track corners into ramps is rather unintuitive and complicated. Since engraving tracks always requires two tiles to connect in a straight line as input, you have to give two separate designations for a single job: a track bit from the ramp tile to the "below" direction and another one to the wall of the "upward" direction. If you wanted to change direction on a ramp from east to north:
{{diagram|spaces=yes|\
z +0 z +1
░░░░░ ░░░░░
░░░░░ ══╗░░
=▲░░ ░░▼░░
░░░░░ ░░░░░
}}
you would need to connect the ramp on z +0 both to the west and to the north by issuing two "carve track" commands, one selecting the ramp and the track tile to the west, and another connecting the ramp tile with the wall to the north. An engraver would then carve a NW track corner into the ramp, allowing carts to pass the corner correctly both going up and down. Such track corners are perfectly serviceable for guided carts, but moving down a route of several of them by pushed or ridden cart is problematic - ramps on corners behave very counter-intuitively, resulting in loss of speed when going down and diagonal movement when going up.

Moving to and from ramps (or between ramps "pointing" in different directions0 causes some non-trivial adjustments to speed and even moving along the tiles at a fixed speed ''unrelated to the entry/exit velocity values'', because transitions to/from ramps are processed differently and are not to be "skipped". This affects compact track/ramp combinations (such as e.g. a simple 2x2 ramp spiral) most, and combined with bouncing often makes them work not in the way one could expect. {{cite forum|144328/5705102}}

{{anchor|Tracks}}

=== Hauling route ===
A hauling route is a list of directions describing how and under what conditions a minecart will move. The proper setting up of routes is essential for a working rail system. Routes, stops, departure conditions and stockpile links are managed from the {{k|h}}auling menu.

==== Route ====
A route defines the path a minecart will take along a track, as well as under what conditions it will move or stop moving. A route is made up of stops. Stops are precisely what they sound like, a position on the track at which you want a minecart to stop. A minecart track might use as little as a single stop for a looped track, which will serve as both a starting and stopping point for the cart, or it could contain many stops, perhaps to load supplies or wait for a bridge to be manually lowered, before reaching its destination or returning to its starting point. It is important to note that you only need to place stops on a route where you actually want the cart to stop and wait for some action to occur. They are not needed to help navigate the cart along the track beyond telling it where on the track to stop.

New routes are created with the {{k|h}}auling key. Existing ones can be removed (without confirmation) with the {{k|x}} key, and also {{k|n}}icknamed. Before operating, the route must have a {{k|v}}ehicle assigned to it (this can be done with either the route or a stop selected). Assigning a full minecart to a route may result in a slow hauling job if the contents are heavy.

==== Stops ====
Stops are the individual waypoints that make up a hauling route. A given stop consists of the location of a tile, as well as conditions describing when, where, and how a cart should be moved after being stopped at that tile. Stops can be created from within the {{k|h}}auling menu, by placing the cursor over a tile and hitting {{k|s}} while highlighting the route (or a stop within) you've already designated. A minecart will begin its route at the first stop created, and continue through each subsequent stop, being guided, pushed, or ridden from each stop to the next depending on the conditions specified. In many basic minecart applications, the cart will end up at the same stop it began at, though this is not always the case. It is important to note that hauling stop order is enforced, even if there is no track. A dwarf will drag the cart overland back to a skipped stop in the route's list if your tracks bypass it somehow.

Once a stop has been placed, it is given a default set of conditions under which to move the minecart if it is stopped there. Each new stop gets the same default conditions regardless of the track it is placed upon (e.g. guide the cart to the north). For this reason new stops might get marked by yellow exclamation marks ({{DFtext|!|#ff0}}) due to invalid directions. One important thing to note is that as you place additional stops, the display will show paths between the stops you have defined. However, this is '''not''' necessarily the actual route the minecart will take once the route is in operation. For example, if a route were defined with two stops at opposite ends of a track with many twists and turns, a line will be drawn directly between those stops to show the order in which they will be visited. These route lines may crisscross all over the tracks, but so long as the track is valid end to end, the cart will follow the track from one stop to the next, even across twists, turns, and z-level changes. Stops, which are the steps that make up a route, should not be confused with Track Stops, described below.

===== Stockpile links =====
By placing the cursor on top of a stockpile and using {{k|s}}, you can create stockpile links while defining a hauling stop. Links can also be redefined by selecting them, placing the cursor over a different stockpile, and pressing {{k|p}}. The cart will then be filled by items present in its various linked stockpiles in preference to other items. Note that bins should be used with caution in stockpiles that are linked to minecarts. Bins cause problems when used with the "Desired Items" list in a stop's conditions. For example, if a minecart is set to accept only granite blocks, and to depart north when it is 100% full of granite blocks, it will not depart if any of those granite blocks are in bins, even if bins are also included in the desired items list. Two solutions to this problem exist as of v0.40.24. First, bins can be disallowed in stockpiles that are linked to stops. Alternatively, bins '''can''' be used in conjunction with minecarts provided that the minecart's departure conditions use only "any items" instead of "desired items." This option can be toggled in the advanced conditions menu for a stop, accessible via the {{key|C|}} key. The cart's contents can still be controlled by specifying what items are allowed in the linked stockpile.

===== Departure condition =====
Departure conditions involve setting conditions in which the minecart will leave on the route. Each condition includes:
# A departure mode (Guide, Ride or Push).
# An initial departure direction (NSEW). Note that this defines the initial direction of movement only. Even if a track includes many turns, as long as the initial movement direction is valid the cart will follow the minecart track thereafter.
# A timer, before which the departure condition cannot be met.
# Conditions on the amount of items in the cart.
Departure conditions are created with the {{k|n}} key. A new departure condition will read: "guide north immediately when empty of desired items". This condition can be changed between basic presets with {{k|c}}. "Advanced" mode ({{k|C}}) allows for more precise control over departure conditions: fine tuning the percentage from 0 to 100 in 25% steps ({{k|f}} and {{k|F}}), switching it being either the maximum or the minimum amount of items for the condition to be met ({{k|m}}), and whether the cart accepts all or only a specific set of items ({{k|l}}). Common to both screens are the departure mode ({{k|p}}, Push, Ride or Guide), {{k|d}}irection, and timer ({{k|t}} and {{k|T}}) options.

To have a cart only carry a specific set of items, the stop can be set to only carry "desired" items, opening the selection screen with the {{k|Enter}} key while having said stop condition selected, and toggling as desired, or it can simply be linked to a stockpile and set to depart once it is full of items from its linked stockpiles, regardless of type.

=== Track Stops ===
A Track Stop, not to be confused with a route stop, is an optional, single-tile construction which serves two purposes. First, it can be used to cancel a cart's momentum in order to slow or stop it as it passes over the Track Stop. This might be necessary if a cart were pushed down a series of ramps to its destination. Second, a Track Stop can cause a cart to automatically dump its contents as it passes over the Track Stop. Track Stops are constructed via {{k|b}} {{k|C}} {{k|S}}, and must be constructed atop an existing piece of track. If a Track Stop has been set to automatically dump a cart's contents, the cart will dump its contents in the direction indicated when it passes over the Track Stop. Depending on the friction settings chosen for the Track Stop, the cart might then stop after dumping, or it might continue on its route to another destination.

Track Stops are not mandatory; in fact, their main use is in automated rail systems. However, even in basic rail systems it can be useful to set a Track Stop to dump items: this saves time that dwarves would otherwise spend in removing items from the cart, time that is better spent driving the cart back to where it's needed. Dumping will occur even with a guided cart. '''Take care not to set Track Stops at a loading site to dump their contents''', or dwarves will never be able to fill the cart. It will dump any contents the moment they are loaded.

Counter-intuitive to their construction method, Track Stops are considered [[building]]s and must be removed by {{k|q}} {{k|x}}.
* See [[#More_on_Track_stop |More on Track Stops]]

=== Step-by-step tutorial ===

Let's construct a simple minecart route. This route will move stone blocks from an input stockpile to an output stockpile. We'll begin by creating the stockpiles:

[[File:minecart-example-1.png|Stockpiles designated.]]

The input stockpile is on the left; the output stockpile is on the right. We'll be moving blocks from left to right. Disable bins in both stockpiles, and set the input stockpile to accept only from links. Then make the stockpile take from the mason's workshop where the blocks are being produced.

Next, carve the track:

[[File:minecart-example-2.png|Track carving designation.]]

Note that the ends of the designation are uniquely shaped; this is automatic, and not anything you need to control. Now, wait for your engravers to come along and carve the track into the stone. (Your haulers will probably also fill up the input stockpile while you wait.)

In addition, while we're waiting for that to happen, we'll build an iron minecart in the forge.

[[File:minecart-example-3.png|Track carved.]]

When the track has been carved, it will look like the above (the track will be solid instead of flashing). Now, order a track stop to be constructed next to the output stockpile:

{|
| [[File:minecart-example-4.png|Track stop designation.]]
| [[File:minecart-example-5.png|Select dumping direction.]]
|}

You must press {{k|d}} three times to select the dumping direction ''before'' placing the track stop. We want our blocks to be dumped into the output stockpile east of the track stop. Then wait for a mechanic to come along and build the track stop.

[[File:minecart-example-6.png|Track stop constructed.]]

Now we'll define the actual ''route''. This is done in the {{k|h}}auling menu. Press {{k|r}} to begin defining a route. Next, move the cursor to the input end of the track, and then press {{k|s}} to define the first stop:

{|
| [[File:minecart-example-7.png|Stop 1 designation.]]
| [[File:minecart-example-8.png|Route definition, in progress.]]
|}

Move the cursor again, to the output end of the track, and press {{k|s}} again to define the second stop:

{|
| [[File:minecart-example-9.png|Stop 2 designation.]]
| [[File:minecart-example-10.png|Route definition, two stops.]]
|-
|
| [[File:minecart-example-11.png|Stops are not defined yet.]]
|}

There are several user interface features to note at this point. The stops have been positioned, but they haven't been ''defined'' yet, so there is a warning {{DFtext|!|#ff0}} symbol by each of them. In the lower right corner, we see what the {{DFtext|!|#ff0}} means. Also, note that the second stop is labeled in white, while the other two lines are grey. The white text is a selection indicator, and can be moved up and down by pressing {{k|+}}/{{k|-}}.

Next we need to define what our stops do. We want the minecart to be filled with blocks at the first stop, then travel to the second stop where it will dump its cargo, and then return. Press {{k|-}} to move the selection up to stop 1, and {{k|Enter}} to open it up. By default, the stop has three conditions:

[[File:minecart-example-12.png|Default stop definition.]]

We don't want any of these, so press {{k|x}} three times to delete them. This leaves us with a blank stop. Now we can add the conditions we actually want. Press {{k|n}} to begin adding the first condition, then {{k|d}} twice to change the direction from north to east. Then press {{k|c}} to change the condition from empty to full. This will instruct the minecart to be guided east when full of desired items.

To set the desired items, we create a stockpile link. Press {{k|s}}, then move the cursor to the input stockpile, then press {{k|p}} to select that stockpile. Now press {{k|Enter}}; this opens up a selection screen that resembles the stockpile customization screen. Move down to Blocks, {{k|e}}nable them, then (if you wish) restrict it to stone blocks.

When you've done all that, stop 1 should look like this:

[[File:minecart-example-13.png|Stop 1, defined.]]

Stop 2 is much simpler. All we need to do is have the minecart return to the input stop. So, make a condition and change the direction:

[[File:minecart-example-14.png|Stop 2, defined.]]

Finally, we just have to assign our minecart. Go back to the route definition screen, and press {{k|v}}. Select the minecart, and press {{k|Enter}}.

Now we've got everything set up:

[[File:minecart-example-15.png|Route, fully defined.]]

The V is red because the minecart hasn't been moved onto the track yet. Some dwarf will have to haul it from the forge to the first stop, by hand; this will take a while, especially if the forge is far away.

Once the minecart is in place, dwarves should fill it with blocks from the input stockpile, which will in turn be filled with blocks from the workshop where your mason has been toiling dutifully. When the minecart is full, the blocks will be dumped into the 1x1 stockpile on the right. Automatic quantum dumping!

=== Troubleshooting ===

Because of the complexity of the system, all but the most careful and experienced minecart users will encounter issues. Most route issues can be diagnosed and fixed from the {{k|h}}auling menu.

'''Symptom:''' {{DFtext|! Set dir/connect track|6:1}} message appears to the right of one or more stops

'''Possible Causes:'''
* The departure direction of the stop might be invalid. Edit the stop using {{k|Enter}} and press{{k|d}} until it is pointing in a valid direction.
* The track stop might not be built on top of a track. The track stop must be deconstructed to remedy this issue.
* Your track might not be built correctly. Make sure all connected tracks between destinations are not one-way tracks.
** This can be especially confusing with ramps. To carve a two-way track on a (natural) ramp, you must designate the ramp and one square beyond in the direction you want the track to go.
** Ramps '''must''' have a solid block on the side opposite to the track, or they will neither work nor be marked as "unusable". The solid block can be natural or constructed.
* The desired/kept items might not be configured correctly.

'''Symptom:''' The status '''0% V''' always appears to the right of one stop.

'''Possible Causes:'''
* The stop may not be set to take from a stockpile. Edit the Stop using {{k|Enter}} and make sure you see a message like "Take from Stockpile #1".
* The take conditions must correspond with the contents of the stockpile.
* The track stop may be set to dump. A track stop set to dump cannot be filled. You must either set the stop to a time-based departure or deconstruct the track stop and rebuild it without dumping. (Alternatively, with [[DFHack]] you can modify "Dump on arrival" to "No" using the {{key|q}} menu without rebuilding the stop.)
* Make sure the minecart itself has not been designated to be dumped (such as when using mass-dump).

'''Symptom:''' Dwarves fill the minecart properly, but will not move it thereafter.

'''Possible Causes:'''
* The minecart may contain items which are not included in its current stop's desired items. Check inside the minecart using the {{key|k}} and {{key|z}} keys and ensure that all items in the cart are desired items.
* The minecart may contain desired items in bins. Minecarts seem to have problems realizing that they are in fact full of desired items if some of those items are in bins, even if bins are also among the desired items for that stop. '''This cannot be solved by adding the appropriate bins to the stop's desired items.''' Either disallow bins in stockpiles you intend to load minecarts from, or set the departure conditions to rely only on percentage of total load rather than percentage of desired items using the advanced conditions menu ({{key|C}} key).

'''Symptom:''' Dwarves repeatedly attempt to load the minecart, but no items are ever loaded into it.

'''Possible Causes:'''
* This can be caused by using a Track Stop with autodumping enabled at a loading site. Every time a dwarf places an item into a cart resting on such a track stop, the item will be immediately dumped, causing unlimited, useless cart loading jobs. Autodumping Track Stops should never be used at a loading site.

'''Symptom:''' A dwarf picks up the minecart and carries it to its destination.
* See [[#Quirks|Quirks]]

=== Danger ===
Minecarts are not without <strike>danger</strike> [[fun]]. Although designating a track automatically sets the [[traffic]] designation to low, dwarves ''may'' still walk on them, and [[creature]]s ignore traffic designations altogether. If an unlucky dwarf or creature fails to [[dodger|dodge]] a minecart, they can be injured. Most of this danger can be avoided by setting the minecart {{k|h}}auling commands to guide instead of push or ride (dwarves guiding minecarts will ignore traffic restrictions), as well as by [[pasture|pasturing]] domestic animals and preventing the access of other creatures to the tracks. Note that removing the track doesn't reset that tile back to normal traffic priority, so you may wish to manually clean up traffic designation afterward. Also note that bridges that are used as tracks don't have their traffic priority changed automatically (since they're just normal bridges), which could cause dwarves to pathfind normally through dangerous minecart entrances in your fort's walls if you're not careful.

The only <s>fool</s>''dwarf''-proof method is to make the tracks inaccessible. There are several ways to create a track which works for minecarts but doesn't allow creature-traversal; the simplest is perhaps building a [[statue]] on the tracks. Other options include adding single-tile holes (minecarts moving at reasonable speed will jump the gap), vertical drops, minecart-triggered doors, small pools of liquid (4/7 water or 2/7 magma), and hostile creatures overlooking the tracks. For safety, both ends of the track should be isolated, making the dangerous center sections completely inaccessible (though maintenance access can be provided by a locked door).

Danger does not always involve living victims: careless route designation can also result in minecarts careening off tracks or colliding with each other. If this occurs, the [[item]]s may be scattered; this can cause even more hauling jobs than the minecart aimed to eliminate. Even <s>better</s> worse, scattered items, especially [[weapon]]s, can injure passing [[dwarf|dwarves]] or other [[creature]]s; in the words of Toady One the Great, "Accidental grapeshotting of the dining room should be possible now."

Of course, the danger of using minecarts means they can also be [[Trap_design#Minecarts|used as weapons]] by imaginative players.

== Advanced usage and automation ==
Minecart-specific effects are implemented via track stops, rollers and [[pressure plate]]s with "track" condition set. Since all three are considered [[building]]s, they can't be built on the same square (however convenient track stop + pressure plate would be) nor a simple ramp, and are removed by {{k|q}} {{k|x}}.

=== More on Track stop ===
Track stops are constructions that allow further automation of minecart systems via adjustable features such as braking by friction and automatic dumping of contents. They can be built from logs, bars and blocks through {{K|b}} {{K|C}} {{K|S}}; friction amount, dumping toggle and dumping direction must be set '''before''' construction, and these settings can be neither changed nor seen thereafter; however, track stops can be linked to [[pressure plate]]s or [[lever]]s to toggle friction and dumping On or Off (trigger state is inverted: switch On = track stop Off).

If a [[stockpile]] is placed on the tile that a track stop is set to dump to, it can act as a [[Exploit#Quantum_stockpiles|quantum stockpile]] and any items dumped from a minecart that match the storage settings of the stockpile will remain there and accumulate. Normally trackstops are built on top of existing track to operate on moving minecarts, but they can also be used without tracks to create [[Exploit#The_Minecart_Stop|automatic quantum stockpiles]] (see also [[#Step-by-step_tutorial|step-by-step tutorial]]). It is not always desirable to collect ALL of certain items into one quantum stockpile, such as when distributing a material to multiple separate industries. You can link your quantum stockpile to various other stockpiles, ensuring that your dwarves will keep them supplied as necessary. Because quantum stockpiles never fill up like regular stockpiles, it may be a good idea to add a switch to turn them off.

Items dumped from a minecart at a track stop (or dumped by any other means) into open space fall through z-levels until they land on a solid surface. Items falling onto a designated [[stockpile]] will automatically be considered part of that stockpile, even if the stockpile is set to disallow those items (they will, however, be automatically moved to a more appropriate stockpile, if available). Items falling on top of a minecart will '''not''' fall "inside" the minecart. Use with caution; dwarves have fragile skulls.{{bug|5945}}

=== Automated propulsion ===
==== Roller ====
{{Main|Roller}}

A '''roller''' is a [[power]]ed [[machine component]] for the automated propulsion of minecarts. They are built over the top of existing tracks with {{K|b|M|r}}, requiring a [[mechanic]], ''(length/4)+1'' [[mechanism]]s and a [[rope]]. Rollers may also be placed directly on ramps to help pull carts up Z levels. Rollers are very useful to maintain a cart's momentum along long routes, to get them to climb Z-levels without dwarfpower involved, and to get them to reach speeds unattainable by guiding dwarves. These devices are variable-length (1-10), variable-direction and variable-speed ([[Minecart#Numbers_behind_the_scene|see below]]), all traits that can be set at construction time; a roller uses two units of power per tile it is long.

Single-tile rollers transfer power in all four cardinal directions, while other rollers generally only transfer power perpendicular to their activity direction. Longer rollers can also transfer power along their activity direction if built in the correct order, although this can be hard to accomplish and is easily broken. Rollers cannot be powered from above.

Rollers have great acceleration and capped speed. Carts going faster than the roller are unaffected. If a cart moves across an active roller in the direction the roller works and moves slower than the roller's specified speed, the cart will be set to the roller's speed. A cart going against a roller's movement direction will be sent back the way it came (once again at the roller's speed), unless it was moving extremely fast: speed increment of 100000 allows to reverse carts from the full "highest" (50000) speed roller to full "highest" speed back, but ramps can accelerate a cart beyond this. {{cite forum|144328/5702453}}
A cart crossing over a roller perpendicular to its current movement direction will gain the roller's amount of speed in the perpendicular direction without directly changing its forward motion. Without an adjacent wall to constrict its movement, this will typically send a cart off the rails on a diagonal path, completely unable to follow any tracks until it collides with a wall or is otherwise brought to rest. However, if the roller is placed over a track turn and pushes ''from'' the direction of that turn's track, the turn affects carts ''after'' the roller, so they will be forced into the turn rather than derailed in a diagonal direction. {{cite forum|144328/5702453}}

{{diagram|spaces=yes|\
tracks: full:
║ ║
═╗═ ═╢═
║ ║

╢ : roller pushing from W to E
}}
If the roller is powered, carts from ''all'' directions (unless too fast) exit S, because speed imparted by the roller forces carts toward E and ''then'' into the turn.
If not powered, carts from W and N exit S, carts from E and S exit W. Carts above derail speed will ignore the turn, of course.

{{diagram|spaces=yes|\
║ ║
═╗═ ═╟═
║ ║

╟ : Roller pushing from E to W
}}
Carts from the E or W: exit W.
Carts from N: derailed diagonally, exit SW.
Carts from S: derailed diagonally, exit NW.

Rollers affects carts on a track - if placed on a floor or ramp without any tracks, they are ignored. Depowered rollers are also ignored, friction is determined by the tiles underneath.

Because of their one-way nature, rollers are unsuitable for most two-way minecart tracks (unless you set gears toggling roller A->B off while toggling A<-B rollers on). However, a minecart set to be ''guided'' is not affected by rollers at all{{cite forum|109460/3286235}} — this allows a one-way track to be used in both directions. In addition, unpowered rollers do not affect minecarts.

Care must be taken in [[glacier]]s and other extremely cold [[biome]]s, since rollers (and the machinery used to power them) will not operate when constructed on natural [[ice]] floors.

==== Impulse ramps ====
Carts can be given momentum without rollers or changing z-level through a phenomenon called "impulse ramps". A track ramp which is connected both to a wall and to a floor will ''always'' accelerate a cart towards the connected floor tile, no matter where the cart enters the tile from. This means carts can be accelerated as though dropping z-levels, even if the cart doesn't actually change z-level at all. If a track ramp faces three directions such as ╩, then two of those directions need to be facing walls for the cart to be accelerated towards the remaining direction.

Example of straight impulse acceleration:

{{diagram|spaces=yes|\
▒▒▒▒▒▒▒▒▒▒ ▒▒▒▒▒▒▒▒▒▒
═▲▲▲▲▲▲▲▲▲▲═ ═╚╚╚╚╚╚╚╚╚╚═
▒ : Wall
═ : Normal track
▲/╚ : N/E Track/Ramp
}}

If a cart enters from the left, it will speed up on every track/ramp and exit to the right going very very fast - more than one tile every step. If it enters from the right then it will bounce back impulsed by the ramp if it's going slow enough.

As another oddity, carts coming from ramps will in some cases "teleport" through most of the next tile. This is called the "checkpoint effect", and is explained in detail in the Physics section, below. This negates the deceleration of the next tile if it is a ramp "angled" in a different direction. You can just make an upward spiral alternating impulse ramps and regular upward ramps. It takes no power, is quick and cheap to build, requiring only channeling and track carving, and the cart goes up fast, but not so fast that it launches its contents.

Example of an impulse elevator:

{{diagram|spaces=yes|\
z +0 z +1 z +2 z +3
░░░░░ ░░░░░ ░░░░░ ░░░░░
░╔░░░ ░▼╚╗░ ░░▼▼░ ░░░░░
░╝░░░ ░▼░░░ ░░░╔░ ░░░▼░
░▼▼░░ ░░░░░ ░░░╝░ ░╚╗▼░
░░░░░ ░░░░░ ░░░░░ ░░░░░

░ : Wall
╔,╚,╗,╝ : Track/Ramp
▼ : Down Ramp (empty space)
}}

Note that this impulse elevator, due to the checkpoint effect and upward curved ramp effect, will not actually result in carts traveling straight up the ramp. They will lose speed, bounce off a ramp, then be accelerated back into the spiral after a 9-turn delay on both tiles on the floor where they are stopped. This is because the checkpoint effect allows carts to travel up the ramps in a single turn, but also prevents the impulse ramps from adding acceleration unless the cart is slowed to staying on the ramp for more than one turn. Initial acceleration will carry the cart up a variable number of floors before this effect occurs, but this bouncing back and forth will occur every 5 z-levels after the first time the cart stops. When the cart ''is'' traveling upwards, it will pass every tile at a rate of one tile per turn regardless of its actual speed, due to the checkpoint effect. In tracks with only a single cart, this is negligible, but when multiple carts are on the same track (such as when you place multiple carts on a magma cart lift) this can cause collisions which derail carts or cause other unexpected or undesired behaviors.

The following impulse ramp (while larger) should alleviate these problems by using a straight ramp to go upwards, preceded by an impulse ramp to exploit the checkpoint effect and negate up ramp costs. Corners still decelerate carts, so the cart will tend towards a velocity of 72k, which is derail speed. Derail speed breaks (see Controlling Speed, below) may be necessary at the top.

{{diagram|spaces=yes|\
z +0 z +1 z +2 z +3
░░░░░░ ░░░░░░ ░░░░░░ ░░░░░░
░░░░░░ ░╔╔═░░ ░░▼▼╗░ ░░░░░░
░║░░░░ ░▼░░░░ ░░░░╗░ ░░░░▼░
░╚░░░░ ░▼░░░░ ░░░░║░ ░░░░▼░
░╚▼▼░░ ░░░░░░ ░░░░░░ ░░═╝╝░
░░░░░░ ░░░░░░ ░░░░░░ ░░░░░░

░ : Wall
║,═,╔,╚,╗,╝ : Track/Ramp
▼ : Down Ramp (empty space)
}}

Also, if you want to have a cart following a below-derail speed, the following track works well:
{{diagram|spaces=yes|\
z +0 z +1 z +2 z +3
░░░░░ ░░░░░ ░░░░░ ░░░░░
░░░░░ ░══░░ ░▼▼║░ ░░░▼░
░║░░░ ░▼░░░ ░░░║░ ░░░▼░
░║▼▼░ ░▼░░░ ░░░░░ ░░══░
░░░░░ ░░░░░ ░░░░░ ░░░░░

░ : Wall
║,═ : Track/Ramp
▼ : Down Ramp (empty space)
}}
In this elevator, the cart collides with the walls in the corners, but then realigns on the ramp, picks up speed, checkpoints through the next ramp, and slams into the next wall. It is slower (10 ticks per floor) but produces reliable speeds, and will exit the impulse elevator at little more than push speeds.

A sort of opposite effect to impulse ramps also exists: ramps lacking the proper "up" and "down" connections are treated as flat track, even if they actually go up or down z-levels. This allows building "anti-impulse" slopes consisting entirely of ramps only connected up, which a minecart can travel up forty levels and more, needing no more than a single push.

=== Controlling traffic ===

==== Switching ====

As constructions or tile features, [[door]]s and other furniture can be built on tracks. A [[door]] or [[floodgate]] can be turned on or off by a [[lever]], effectively controlling the flow of automated minecarts. This may be <s>dangerous</s> [[fun]], however.
{{diagram|spaces=yes|\
->
A ════┤≡════ B
┤ : roller pushing to East
≡ : door
}}
The roller pushes the cart east, but until the "departure condition" is fulfilled, the door remains closed and blocks the path.

[[Bridge]]s can also act as tracks, but only if they're lowered or not retracted. This property can enable levers to turn tracks on and off. However, care should be taken to ensure that such bridges are never operated while a cart is on top of them, as the cart will be flung off the track. It's worth noting that it's often faster, and cheaper, to construct large bridges than long sections of constructed track.

A powered track switch can be constructed by building an "inverted" corner as illustrated below.
{{diagram|spaces=yes|\
B B
║ -> ║
║ ║
════╚═══ ════├════
A C A C
├ : roller pushing to West.
}}

If the cart is pushed East from the stop at 'A' while the roller is activated, it will arrive at 'B'. If the roller is not running, it will arrive at 'C'. The switch works by the roller first reversing the incoming cart's movement and the cart ''then'' following the track corner.

This switch is very reliable, reacts instantly to on/off signals, and carts of any speed can be switched by this design, although very fast carts will require rollers that are several tiles long, up to three. The requirement for power can be inconvenient or impractical. Non-powered solutions may use controlled derailment, or a connecting bridge.
{{diagram|spaces=yes|\
B ╥
║
║
╞════╝ ════╡
A D C
}}
Here the track between A and C is not continuous. The only continuous track is A->B, with a corner (not a T section). Fast moving carts will tend to derail at D and rejoin the track to C. Placing a door at D will prevent the derailment, so the cart continues to B. The door is operated by mechanisms elsewhere (typically, a lever, but some fun can be had with pressure plates).

Since it depends on derailing, this switch requires a very fast cart, faster than what can be achieved with rollers alone. To gain sufficient speed, a cart must be accelerated further, usually by descending several levels or through impulse ramps. The high speed makes the cart much more dangerous and harder to control.

If carts are moving too slowly to derail at the corner, a retractable bridge may be used as a connector between A and C.
{{diagram|spaces=yes|\
B╥
║
║
A╞════bbb════╡C
}}
The bridge must overlap the corner. Bridges behave like a track crossing, allowing carts to pass in a straight line. When retracted, the corner reappears, so the carts will continue to B. Bridges take 100 steps to react to a signal, necessitating rather long "lead times" when switching tracks via bridge.

As mentioned above, special care must be taken to make sure the bridge doesn't change state while the cart is passing over it. Retracting bridges will throw the cart, causing it to stop dead. Raising bridges can even crush the cart.

==== Controlling Speed ====


Minecarts can reach extremely high speeds, especially when descending multiple Z-levels. A minecart will derail at a track corner if its speed exceeds 0.5 t/st (tiles per step), '''unless''' the route in the direction of travel is blocked:

Will derail at > 0.5 t/st:

{{diagram|spaces=yes|\
in ══╗ -> derailing
║
out
}}

Will not derail at > 0.5 t/st:
{{diagram|spaces=yes|\
in ══╗O
║
out

O : wall/column.
}}

This behavior can be used to build a "speed limiter", that will ensure that when a minecart exits it is traveling below derail speed:
{{diagram|spaces=yes|\
░░░░ ░░░░░ ░░░░░
in ═╔═╗░ ░╔S╗░ ░╔S╗░
out ═╬═╝░ out ═╗═╝░ out ═╗═╝░
░╚S╝░ ░╚═╝═ in ░╚S╝░
░░░░░ ░░░░ ║░░░
in
░ : wall
S : Track Stop (High Friction or lower)
}}
If the minecart is traveling below derailment speed, it will not be affected; if above, will be slowed down and checked again. Granted, you could do the same just with track turns, but it may take a lot of turns and time.

Since all the derailings, bounces and ramps can impart a sideway component of speed small enough to start visible drift many tiles away (say, [[Fun|in the middle of a bridge]]), track turns have one more use: forcing the carts to move strictly along the grid directions. Carts passing a turn below derailing speed convert one component of velocity into another, thus eliminating the drift.

=== Loading liquids ===
[[Water]] and [[magma]] can also be loaded into minecarts by submerging them to a depth of at least 6/7 while standing still or moving at speeds of at most 10000. Loading fluids onto minecarts can be difficult because the added friction provided by fluids can stop a cart in a submerged tile. Curiously, filling a minecart with magma does not injure a dwarf ''riding'' it. A minecart will hold enough fluid to increase the depth of a single tile by 2. This amount is listed as 833 units, which weigh 459Γ (water) or 999Γ (magma). An iron or steel cart filled with magma weighs 1313Γ, while an adamantine cart filled with magma weighs 1007Γ. Since you need a minecart above the liquid's level, possible arrangements may include pressure-activated sluices, rollers (with magma-safe chains for magma), pouring from above to "submerge" it briefly on the same level and drain excess away (dig deeper and leave a vaporizer, though if you could have power for rollers, may as well use a pump) and exploits with ramps (not necessarily impulse ramps, "same height" passing dip does it).
The liquids can be dumped by a constructed track stop.

== Quirks ==
This little quirk concerns dwarf-managed minecarts. If a track which was previously open becomes blocked (ex. flipping a switch connected to a floodgate you've built on the track to raise it) and the conditions for departure are met, instead of refusing to ride/guide the minecart or ride/guide it until it reaches the obstacle, the dwarf will pick up the minecart off the tracks and haul it to its scheduled destination on foot. If the distance is long enough and the weight of the cart heavy enough (due to being filled with heavy items such as stones), the dwarf may drop the cart because of fatigue/hunger/thirst before reaching the destination. This will cancel that vehicle setting job and make another dwarf come by and attempt to haul the cart to the nearest appropriate stockpile where another dwarf will pick up the cart and attempt to haul it to its initial stop. If the stockpile is far enough from initial stop, this second dwarf who is attempting to place the minecart on its tracks may also drop the minecart out of fatigue/hunger/thirst creating a loop that will go on until a dwarf with enough endurance manages to place the minecart where it belongs.

In fact, it seems dwarves are more than happy to attempt to carry a minecart from one stop to another even if just waiting until the track is open again would be the more sane option.

Dwarves will also carry a minecart to its next stop if the direction specified is incorrect (or invalid). This can often occur when using the default departure settings and forgetting to set the direction of each condition.

Dwarves can admire buildings while riding mine carts. Dwarves will not fall asleep during a ride (at least not from being drowsy). If riding on a continuous powered track loop, the dwarf will die of dehydration/starvation as they can not jump off to get sustenance{{cite forum|109460/3377228}}. Dwarves riding in submerged minecarts will gain experience in [[swimming]].{{cite forum|129889}}

Tracks block wagon access to trade depots, unless they're on a ramp. [[Bridge]]s can also be used, as they function as tracks but do not block wagons.

== Physics ==


Minecart physics depend greatly on the departure mode set in the route stop conditions.

When set to "Push" or "Ride", minecarts will move according to the regular laws of momentum, gaining speed when going downhill, losing it slowly due to friction when on a flat plane, and more quickly when going uphill. In these modes, minecarts will move in a straight line until they either are brought to a stop by friction or an obstacle, or until they encounter a turn. A minecart will roll straight past "blocked" ends of T-junctions or track ends, they have no power to restrict a cart's movement. The cart's behavior is largely independent of the weight of its contents (including fluids and dwarves): heavily loaded carts gain more momentum when accelerating, but this only plays a role in collisions: a heavy cart gains just as much speed and is as easy to stop as a light one. In either case, dwarves can not push nor ride an unpowered cart up a ramp, bouncing back the direction it came. At best, this is a waste of time; at worst, it will give your cart-pushing dwarf a [[fun|fun surprise]]. To solve this, the player can either use Rollers (see below) or set the cart to be Guided.

The difference between "Push" and "Ride" is whether the dwarf will go along with the cart or not.
{{DFtext|Push}}: the dwarf will give the cart an initial push, not enough to go up a ramp, but enough to go some way along flat track, and the dwarf will remain at the first stop, ready for a new job.
{{DFtext|Ride}}: the dwarf will give the cart the same initial push and then hop aboard the cart riding with it to the next stop.
{{DFtext|Guide}}: minecarts seem to ignore all laws of physics. That is:
*Ignore the weight of any and all items inside. Therefore:
**Move at the speed of the dwarf that is guiding them. It is thus recommended to pick the most [[attribute#Agility|agile]] of your dwarves for cart-guiding tasks.
*Ignore working rollers.
*Will ''not'' collide with other guided carts even when a full frontal collision would be expected.
*Will go up ramps like nobody's business.
This is therefore the recommended method of transport for simple non-powered rail systems, despite it diverting a dwarf from other, potentially more important tasks.

Some samples with behavior:
{{diagram|spaces=yes|\
A <-> B A <-> C A <-> B
B B B
║ ║ ║
A══╝ A══╩══C A══╬╗
You can only go A->B ╚╝
Works when the cart Works
is in Guide mode.
}}
In the second example above, a cart "pushed" from B will go over the junction and roll off into the unknown south.

=== Numbers behind the scene ===

According to early research by '''expwnent'''{{cite forum|112831/3536975}}:

The minecart has 3 variables for velocity. Velocity can be thought of as tiles per 100000 ticks, so a velocity of one hundred thousand means a cart travels one tile per tick. By going down a large number of ramps, a maximum velocity of 270,000 can be reached, which presents the limit for most practical applications. Short bursts of (much) higher speeds are possible through carefully planned collisions of high-speed carts {{cite forum|137557/5145499}}. (See Perfectly Elastic Collisions, below.)

Every tick the cart adjusts sub-tile position units by the amount of their velocity, as well as adjusts velocity depending on current tile (speed is reduced by the "friction" of the tile, or accelerated if going "down" a ramp). On flat (non-ramp) tiles, the cart will move to the next tile when the sub-tile position goes either above 100,000 or below 0, (or several tiles if velocity is over 100,000,) and 100,000 is either added or subtracted to sub-tile position to restart the count to the next tile change.

Since most deceleration and acceleration is applied per step, with the notable exception of corners, a cart going at twice the speed of another one can cover about four times the distance in a straight line, but only twice the distance along a winding track with very many corners.

A push will teleport a cart to the beginning of the next tile (NOT the middle!) in one tick with 19990 speed (10 speed is lost due to track friction), while a roller will give a cart the roller's set speed, and it will start to accumulate regular track friction past the middle of the roller tile. Some track features will affect a minecart when it is past the middle of the previous tile: entering a ramp or a hole/drop will happen when the cart has left the middle of the previous tile, and the ramp will gain additional distance unit depending on the leftover units from the previous tile. When a cart leaves a ramp it will emerge after one tick in the middle of the next regular tile, so its entry coordinate is "50000-speed+friction". Rollers also affect the speed of minecart from the middle of the previous tile.

Friction of tiles:
{| class="wikitable"
|-
! Tile
! Friction
! Comment
|-
| Tracks
| 10
|-
| Ground/Floor
| 200
|-
| Unusable ramp
| 10
|-
| Upwards ramp
| 4910 (10+4900)
|-
| Downwards ramp
| -4890 (10-4900)
|-
| Roller
| ±100000 (but capped by the set speed)
|-
| Corner track
| 10
| Speed reduced by 1000 upon leaving the corner tile
|-
| Track stop (highest)
| 50000
|-
| Track stop (high)
| 10000
|-
| Track stop (medium)
| 500
|-
| Track stop (low)
| 50
|-
| Track stop (lowest)
| 10
|-
| Water 1-6
| Additional (WaterLevel - 1) * 100
| rowspan="2" | [[#Skipping|See Skipping]]
|-
| Magma 1-6
| Additional (WaterLevel - 1) * 500
|-
| Empty space
| 0
|}

Water of depth 7/7 provides a friction of about 10000 per step, as does maximum-depth magma. This higher friction may not apply to very slow-moving carts.

Impulse sources:
{| class="wikitable"
|-
! Feature
! Speed
|-
| Push
| 20000
|-
| Roller lowest
| 10000
|-
| Roller low
| 20000
|-
| Roller medium
| 30000
|-
| Roller high
| 40000
|-
| Roller Highest
| 50000
|-
|}

Note, again, that nearly all of these values are applied ''per tick'', rather than ''per tile''. The exceptions are curves, which is 1k deceleration per direction change at the half-way point of the tile, and rollers, which ''set'' the speed every tick. This makes rollers particularly useful in high-deceleration situations, such as underwater, but require that ''nearly every tile'' in such high-deceleration situations have a roller.

A cart heading up a ramp can experience deceleration on multiple ticks, (and stays on the tile more ticks the slower it is going, resulting in greater deceleration,) and as such, a cart leaving a "Highest Speed" roller with 50k velocity will not be able to climb 10 consecutive straight ramps, since they are ''not'' "5k deceleration each". In fact, the first ramp not on a roller will be -15k velocity,

=== Sub-tile Positions and Velocity ===
Carts store six values that are unique to them. Three sub-tile position values, and three velocity values. (X, Y, and Z.)

Note that the Z position and velocity only matter when a cart is in flight. (See Falling and Cart Jumps, below.)

Each non-ramp tile is functionally composed of a value between 0 and 100,000, with a "centered" cart sitting at the 50,000 point in all three directions. When a cart has velocity, it is added or subtracted from the current position every tick, and then a friction force is applied to the cart.

In essence, every sub-tile position unit is a decimal value of a tile, 0.000001 tiles, in a game that largely prefers integer values.

When carts move beyond the maximum or minimum value of a tile, they physically move a tile on the map, and start at the far end of the sub-tile position the next tile. (I.E., traveling West, a cart that starts a tick at 15,000 X sub-tile position and has an X velocity of -20,000 would move to -5000 X sub-tile position, which is out of bounds for that tile. As such, it will travel one tile West, and start the next tick at 95,000 X sub-tile position. It will also lose 10 velocity in that tick due to friction with the track if it is on a track, or 100 velocity if it is on regular ground, or no velocity if it is airborne.)

Ramp tiles are longer, approximately 144,000 in the direction where it "slants downward", (to approximate a 45 degree slope, it is square root of two times longer,) and centered at 72,000. Because of this, a cart with no velocity dropped from a hatch will land at the center of a tile, at position 72,000, and 72,000, and will start rolling in the ramp's "downward" direction, picking up the ramp's acceleration (4890 per tick in the direction of the ramp's "downward" direction) every single tick, then moving that sub-tile amount every tick. (This results in a cart that takes 5 ticks of acceleration to leave its ramp - 6 ticks overall - and to leave the ramp with about 23k velocity, slightly more than a push.) When it enters another ramp ''facing the same direction downwards'', a cart will start at the 0 or 144,000 position, and have twice as far to travel. This means that if a cart enters a ramp from the side, it will gain twice the momentum of simply starting at the midpoint of a ramp.

Note that passing from one direction of ramp to another or to flat terrain causes unintuitive behavior, "teleporting" to the midpoint of another tile in what is called the "checkpoint effect", below.

Note, however, that sub-tile positions are carried over from tile-to-tile. This separate tracking of velocity and position between X and Y can lead to problems with diagonal motion:

{{diagram|spaces=yes|\
z0 z-1
▒║▒ ▒▒▒
═▼═ ▒╬▒
▒ ▒ ▒║▒
▒ : Wall
═, ║ : Track
╬ : Track and Ramp
}}

If a cart is passing West-to-East over this setup, the valid ramp to the South will apply "Southward" acceleration to the cart (-Y velocity) as it passes through the ramp tile. Assuming it only spends one tick in that tile, it will still have gained about -5k Y velocity, which will still apply motion Southward. If the tracks continue straight for another 11 tiles, it will have accumulated enough Southward motion to try to move a tile South, even if all tracks are facing East-West.

'''Non-curving tracks do not correct this motion'''.

They don't "tip back over" without adjustments in the track. Any value of sideways motion on tracks larger than 990 will lead to a derailment. (Lower values will be nullified by friction before they are enough to lead to derailment, but there is currently no way to apply such a small amount of velocity.)

If the tile to the South is a wall at that point, it will be considered a collision with a wall that ''halts all motion''. If the tile is open, it will generate a diagonal track derailment that will send a cart flying until it strikes a wall, at which point it will not re-rail itself. In almost any circumstance, this is undesirable behavior.

The only way to appropriately deal with this is to either cancel out this behavior with an equal amount of acceleration in the opposite direction, or to take a curve.

Note, again, that sub-track position is saved in both directions, so when a cart approaches a curve, it will already have a shorter or longer distance past the curve when it makes the turn.

Curves are applied "halfway through" a tile. If a cart is moving East, and approaches a North-East track at 20k velocity, and friction is eliminated for the purposes of a cleaner demonstration, then when it enters the tile at sub-tile point 0 X, and 50k Y at the start of a tick, it will then move 20k East (+X) the next tick, and be at 20k X sub-tile position, and 50k Y sub-tile position. Next tick, it is at 40k X sub-tile position, and 50k Y sub-tile position. The next tick would take it to 60k X, but that's past the halfway point, so it stops at 50k, turns (and thus loses 1k velocity, but translates the rest from X-velocity to Y-velocity) and travels another 10k. It is now at 50k X sub-tile position, and 60k Y sub-tile position. Next tick, it travels at 19k velocity North, and so moves to 50k X sub-tile position, and 79k Y sub-tile position. Then in two more turns, it leaves to the North.

In the case of diagonal motion due to having velocities in X and Y at the same time, it is critical that the direction the cart is heading in reaches that halfway point in a curve before the cart leaves the track off its sideways velocity direction. If it does so, all sideways velocity is lost, as forwards velocity ''overwrites'' sideways velocity in a curve. If, in that example in the paragraph above, the cart entered at 0 X sub-tile position with 20k X velocity, and 40k Y sub-tile position and -1k Y sub-tile position, it would take that "curve" (or rather, redirection of velocity) on the third turn, while it is at 38k Y sub-tile position to start with, and then move to 47k Y sub-tile position at the end of that tick. It would then move to 56k Y sub-tile position in the following turn, and take 3 turns, rather than just 2, to clear the tile.

But, most importantly, it would be centered in the X sub-tile position, and with the negligible difference of an extra tick, all sideways velocity could be safely ignored.

There are two common ways to gain sideways velocity: Rollers facing perpendicular to the cart's travel path (which, as covered above, are almost always a bad idea, as it is easier to push ''against'' the travel direction of a cart into a curve, which redirects all velocity in the new direction,) and corner ramps, which are covered below, and require a curved track to compensate for sideways velocity within a few tiles.

=== Track Direction Irrelevance ===
Carts that are traveling independently, (that is, not guided,) only care that tracks ''are'' on the tile, not which direction the tracks actually move. Tracks respect only curves (with two exits) and ramps.

This means, for example, that the following tracks, when a (non-guided) cart travels from West-to-East, are functionally identical in effect:

{{diagram|spaces=yes|\
A════════════B A╬║╚╔╣╩╦╠╥╨╞╡B
}}

This is because so far as the cart is concerned, only valid ramps and curves with two exits where there is no exit in the path they are traveling matters.

Hence, if a minecart encounters the end of the track or a T junction with no "exit" in its movement direction, it will simply leave the track and continue on its course in a straight line until it encounters an obstacle, slows to a stop, or encounters another track even if the tile at which it joins the new track instantly sends it around a corner.

In fact, in a track designed for pushes or rides, a "║", a "╦", a "╬", and a "╥" are ''only different in appearance'', and are ignored by an unguided cart, which will continue in its current direction, regardless of the track. For any purpose but guided tracks, ''only curves and ramps matter at all''.

Tracks like T-junctions, however, ''are'' respected by dwarves guiding carts, who will lift and carry carts if they cannot find a valid track to their destination, and can choose to follow any orthogonal direction at a four-way junction in much the same way as they normally pathfind. What this functionally means is that T and four-way junctions ''only guide dwarves hauling a cart, not carts, themselves''.

Carts only check for curves when they are halfway through a tile. When they get there, they look to see if their path has no exit. (That is, if it is traveling East, it checks if there is an East exit.) If there is, it ignores all other track directions, and keeps traveling. If there is not, it checks to see if there are only two exits to the track, and if one of those directions was the direction it "came from". (That is, if traveling from the East, it checks if there is a valid exit to the West, and if so, if there is either a North exit or a South exit.) If there is not, it ignores the track anyway, and keeps on traveling as though it were still on track. If there is, it will subtract 1000 from the velocity of the cart, and redirect all forward velocity to the direction of the curve. This change in the direction of velocity ''overwrites'' any "diagonal" velocity, which can prevent diagonal velocity derailments, but any perpendicular velocity is not preserved, and is instead discarded.

=== Valid and Invalid Ramps ===
Ramps are functionally defined for cart purposes as being a tile which exerts an acceleration force upon its "downward slope", and which allows connection to tracks a z-level above or below. This downward slope requires a cart to have one ''and exactly one'' carved exit to the tile that is the "bottom" of the ramp. Ramps accelerate carts in this "downward" direction (possibly leading to diagonal movement, below), and the deceleration of an "uphill" ramp is actually just the acceleration being applied against the direction of a cart's movement.

This is where players can find an exploit in the behavior of ramps - if there are ''two'' "downhill" exits to a ramp (such as a "T junction" on a ramp where only one exit faces a wall), then the ramp provides no acceleration ''or'' deceleration, allowing carts to travel up ramps without any loss of momentum except for the standard "flat track" deceleration, because as far as the cart is concerned, the track ''is'' flat. (A T junction is also not a curve, so the track is considered flat and straight no matter what direction the cart is traveling.)

Similar effects can be achieved when there are ''no'' "downhill" exits to a ramp. This may be the case if you have, for example, an East-West track with a one-tile channel with a ramp in it. The cart will travel through the "dip" with no change in velocity. It can also be the case if you abuse the Track Direction Irrelevance, above, and set only exits ''up'' the ramp, and none leading ''down'' the ramp. For example, if a cart is traveling from West to East up a slope, only carving East exits on each tile of ramp will make the cart travel up the ramp, and then recognize the tile it is on as being a "flat" tile, thus ignoring any deceleration from traveling uphill.

Note that this effect only reliably occurs at below-derail speeds as the cart will treat the ramp as an invitation for a ramp jump otherwise. (This almost always results in a collision with a wall that will stop forward progress.)

=== Falling ===
When falling, a minecart appears to cause no damage upon collision, possibly to allow cart "stacking" across Z-levels.{{cite devlog|2012|04|06}} A dwarf riding in a minecart that is dropped multiple z-levels suffers normal fall damage. Minecarts can fall through up/down stairs.

While airborne, carts do not feel the effects of friction in any horizontal direction, and will continue until they strike an obstacle. Carts that land on tracks instantly re-rail themselves regardless of track directionality.

Falling carts accelerate similarly to the way that a ramp will accelerate a cart in a special z-only velocity that only applies to airborne carts. (Actually, acceleration due to gravity in freefall seems curiously slightly ''slower'' than ramp acceleration.) Ramp acceleration, while it logically should be partially z-directional, is only recorded as x- or y-directional, and there is no translation of z-directional velocity upon landing. Landing carts zero out their vertical velocity upon landing, even when landing on ramps, although carts that had horizontal momentum while falling preserve it.

This means a cart falling (from a hatch, thus with no horizontal speed) onto a track ramp is accelerated as if starting from the middle of the ramp - i.e. to the same speed, no matter how many Z-levels it was dropped, vertical velocity is negated. {{cite forum|144328/5701211}}

Carts falling onto a floor can, however, cause damage to creatures ''one tile below the floor''. This can be used in an [[exploit]] called a "thumper", where carts are caused to repeatedly fall on a floor above an entrance to the fort, inflicting significant damage (as though it were a collision) on those below the cart.

=== Cart Jumps ===
Carts that cross off of "up" ramps relative to their current direction of travel, which do not have a ceiling above them, are traveling above derail speed, and do not have valid ramp track before them can translate a portion of their horizontal velocity into vertical velocity, causing a cart to be projected into the air until vertical velocity is negated and overcome by the gravitational acceleration. Because downwards acceleration is applied per-tick, this creates a reasonable facsimile of the parabolic motion of an actual object rolled up a ramp and launched with significant speed.

{{diagram|spaces=yes|\
z0 z0 hiding ramps z+1 A z+1 B (hidden ramp)
▒▒▒▒▒▒▒▒▒▒▒▒ ▒▒▒▒▒▒▒▒▒▒▒▒ ▒▒▒▒▒▒▒▒▒▒▒▒ ▒▒▒▒▒▒▒▒▒▒▒▒
═▲▲▲▲▲══▲▒▲═ ═╚╚╚╚╚═══▒══ ▼▼▼▼▼ ▼═▼ ▼▼▼▼▼ ▼╚▼
▒ : Wall
═ : track
▲ : Ramp
}}
In this diagram, if there is no ceiling above it, the track in z+1 A will launch its carts airborne when they travel across the ramp. z+1 B (with a ramp on the tile on the hill) will not launch the cart. The cart would also not be launched with ''any'' valid ramp, even if it does not travel in an appropriate direction, such as North/South (which the cart will ignore, as it is not a curve, anyway, although it may produce acceleration that may cause diagonal movement.)

Carts that are traveling at derail velocity will also start "jumping" from the track if it hits an un-tracked tile, flying over and ignoring any tracks until it is ready to land. Carts that land upon tracked tiles re-rail themselves, and clever designers use this feature to jump over curved track sections in one direction or another. (Retracting bridges over untracked tiles can cause jumps or not cause jumps depending upon the status of the bridge.) Minecart speed must be carefully regulated to ensure reliability of jump length.

Hitting untracked tiles at around 70k velocity creates a vertical component to acceleration that allows for jumps of around 6 (horizontal) tiles that do not actually leave the z-level the cart is on, but which do apply z-direction velocity on the cart, as per falling.

Carts that approach a downward slope at a high enough velocity will also make a jump, (or rather, ignore the ramp and fly forwards) but will not do so if the Checkpoint Effect (below) is exploited through an impulse ramp before the actual downhill as the impulse ramp "tricks" the cart into thinking it has already started going downhill. The cart will also not fly off the ramp if there is a wall and ceiling preventing any motion but going down the ramp.

=== Skipping ===
If a minecart is moving fast enough, it can skip over [[water]] or [[magma]], making splashes of [[mist]] (or [[magma mist]]) as it attempts to move on them horizontally. This horizontal movement is independent of the minecart and its content's [[weight]].

Skipping causes significant friction on the cart, and even a cart going at max speed from ramps can only make about 50 tiles without requiring re-acceleration. (Carts that decelerate enough that they do not trigger the skipping effect will, of course, sink.)

=== Corner Ramp Derail ===

Corners on upward ramps can cause diagonal movement, forcing a derail even if the cart has a wall next to it, which will force a stop when it touches a wall that forces dwarves to manually reset the cart.

This is caused by the fact that a cart, after turning the bend in the track halfway through the length of the tile, will still "accelerate down", which is now perpendicular to the movement of the cart, causing acceleration to occur in two directions. (Down corner ramps do not have this problem, as when they pass the halfway point, all perpendicular motion is added to forward motion, and after that curve, all downward acceleration is in the forward direction.)

There are two fixes to this problem. One is to simply not put corners on up ramps. The other is to take advantage of the Checkpoint Effect, below, by making a ramp (possibly including an impulse ramp) one tile in front of the ramp to make it skip through most of the tile before sideways momentum can be built.

=== Checkpoint Effect ===
The checkpoint effect, [http://www.bay12forums.com/smf/index.php?topic=144328.0 explained in depth by Larix], is an odd and highly exploitable feature of ramps where minecarts "teleport" through the next tile of track, ignoring nearly all minecart physics (except that they stop at all walls or other obstacles and only respect curves with no backing wall and invalid ramps if they are below derail speed) and passing through that tile in just a single tick, and into the next tile at the halfway point.

This effect occurs when a cart leaves a downward ramp for any other direction of tile. (This includes ramps which accelerate in different directions, even a ramp which goes from accelerating East to accelerating North due to a bend in a chain of standard down ramps in a curve.) This allows, for example, two valid straight ramps directly next to one another with a cart dropped onto one or the other with no momentum to have the cart pick up acceleration going "down" the ramp as normal, but then flying up through the "up" ramp it travels into with no loss of momentum, as though it had come from an impulse ramp. If the two ramps had at least one space of distance between them, and then a cart were dropped in, the cart would instead "rock" back and forth between the two ramps.

This seems to be because ramps have a slightly longer length than regular tiles - 144,000, rather than 100,000 distance. When this "snaps back" after a ramp, it seems to project the cart suddenly further along the track, making it jump a tile ahead even when otherwise moving at relatively low speeds.

This [[bug]] is the cause of a ''wide array'' of unexpected behavior among people who do not take this bug into account. It causes derailments or failure to climb up seemingly valid impulse elevators. In general, it makes a system that behaves extremely counter-intuitively, and operates ''any time a cart encounters a valid ramp''. At the same time, when its effect is accounted for, it is highly exploitable: It causes "perpetual motion devices" using no power when two opposing ramps are placed next to one another, since the "uphill" effect of the opposing ramp is ignored, preventing deceleration.

Another useful thing to note about this exploit is that carts traveling at no less than 72,000 or so speed (enough to travel half a ramp tile in a single tick) can travel through every tile in just one tick at no change in velocity as long as the tiles alternate between impulse ramp or actual down ramp and any other tile type. The cart checkpoints through the non-down-ramp tiles, and can pass through the (impulse) down ramp tiles in a single tick, before they can actually start gaining momentum.

{{diagram|spaces=yes|\
▒▒▒▒▒▒▒▒▒▒ ▒▒▒▒▒▒▒▒▒▒
═▲═▲═▲═▲═▲═ ═╚═╚═╚═╚═╚═
▒ : Wall
═ : Normal track
▲/╚ : N/E Track/Ramp
}}

If the cart enters from the West at less than 72,000 speed, some of those ramps will cause Eastward acceleration.

This means that an impulse ramp not contiguous to other impulse ramps has a top speed of around 75k:

{{diagram|spaces=yes|\
▒▒▒▒▒ ▒▒▒▒▒
▒╔═╗▒ ▒╔═╗▒
▒╚▲╝▒ ▒╚╗╝▒
▒▒▒▒▒ ▒▒▒▒▒
}}
This setup makes a cart that travels clockwise at a speed that fluctuates around 75k velocity. If the cart has more than 72k velocity, it fails to accelerate in the ramp, as it leaves the ramp in a single turn due to checkpointing to the halfway point. After that, the curves sap 1k velocity, and every tick saps 10 velocity.

Two contiguous impulse ramps with a same-facing "downwards slope", however, do not suffer the checkpoint effect in the second tile, giving functionally triple the space to accelerate. This means it will add velocity (at the standard rate of 4.9k per tick) up to a maximum speed of 216k.
{{diagram|spaces=yes|\
▒▒▒▒▒▒ ▒▒▒▒▒▒
▒╔══╗▒ ▒╔══╗▒
▒╚▲▲╝▒ ▒╚╗╗╝▒
▒▒▒▒▒▒ ▒▒▒▒▒▒
}}
This example results in a cart moving three times as fast as the previous cart.

Three successive ramps results in the highest attainable speeds.

In practical terms, this means that only consecutive ramps should be used for high acceleration, but singleton ramps can be used to have speeds that are somewhat regulated.

=== Stacking ===
If a minecart lands on top of another minecart, they may form a stack, with the upper cart on the z-level above the lower. Subsequent carts do not form a stack, but rather quantum stockpile in the same space. This behaviour is useful for [[megaprojects]] and [[trap design]] with minecarts as the weaponry. Moderation should still be exercised: carts take longer to fall into a "stacking" tile already occupied by other carts and will spend that time "hanging" in the air above the stack. This can lead to following carts striking them, which can cause all kinds of malfunctions. The extra time is two game steps for every cart already in the stack, which doesn't hurt stacks of ten carts very much but makes stacks of 100+ rather impractical.

These minecarts on the upper level generally need to be struck with another minecart to move out, or have their support removed. The latter option is safest done by shooting it away with another minecart, manual removal of a stack-supporting cart typically causes the next cart from the stack to [[fun|fall on top]] of the hauler.

=== Perfectly Elastic Collisions ===
Minecart collisions are perfectly elastic, meaning that not only do minecarts not take damage, but that two carts that are rolling which have frontal collisions of near-similar speed, and where one cart is no more than twice the mass of the other cart, will result in a billiard-ball-like effect of the lighter cart bouncing off the heavier cart with a proportional speed increase dependent upon the relative momentum behind the heavier cart.

Using this trick with carts already at the 270,000 maximum speed from ramps can result in "supersonic" carts traveling at speeds in the millions (travelling a dozen tiles per tick), but where they are suddenly subject to 10,000 units of "terminal velocity" friction per tick. [http://www.bay12forums.com/smf/index.php?topic=137557.0 Thread with SCIENCE here].

While hypothetically capable of launching a minecart into orbit when used in conjunction with a ramp, no cargo can be contained in the launched cart, as the collisions will force ejections of the cargo. Your "unwilling volunteer" [[goblin]] space pioneers will simply become paste underneath the wheels of an extreme high-speed cart.

== Non-standard uses ==
Minecarts include some interesting characteristics that have motivated uses beyond hauling. They can be useful for creating fully-automated [[exploit|quantum stockpiles]] and [[garbage disposal]]s. Storing perishable goods (meat, meals, etc.) inside a minecart appears to guard against rot and vermin.
Minecarts can be [[Trap_design#Minecarts|used as weapons]], or as (hopefully non-fatal) triggers to restart stalled [[healthcare]]. They can also be used to time/control game events, either using a basic [[repeater]] or much more advanced [[minecart logic]].
Minecarts trigger [[pressure plate]]s, which means a trap can be designed to trigger when a thief attempts to steal a minecart.
A pressure plate can be used as automatic and more precise custom "launch when full enough" system - as long as weight of your minecarts stays the same. You cannot build a hatch or roller on the same tile, so launch by bumping with another cart. {{cite forum|15096/4580050}}
Dwarves riding minecarts can attack enemies within reach (which goes back to dev log). This applies to shooting, and they actually can hit targets while riding by.{{cite forum|109460/5266119}} Whether a minecart protects the rider and how it interacts with dodging is not known yet. Minecart riders can also [[Swimming#Minecart_training|train swimming]] and [[Megaprojects#Surveillance_Track|detect ambushers]].

== Adventure mode ==
In addition to being used for hauling, minecarts can also be ridden in [[adventure mode]]. (Adapted from forum thread {{cite forum|122903/4258212}})

# If the minecart is in your inventory, drop it. If it is already on the ground, proceed to step 2.
# Press {{k|u}} when you are 1 tile away from the minecart (or standing on the same tile as the minecart).
# You will be presented with the following options:
[[File:minecart adventure mode menu.png|left]]
{{clear}}
* If you {{DFtext|Push}} the minecart, it will move a few tiles in the direction you chose. Physics comes into play here, so it will gain/lose speed depending on the usual factors.
* If you {{DFtext|Ride}} the minecart, you will hop into the minecart, even if you were a tile away, and it will move in the chosen direction with you in it. It will gain/lose speed depending on the usual factors. Whilst the minecart is in motion, you should press {{k|.}} to skip your turn; if you attempt to move whilst the minecart is still in motion, the laws of physics come into play, and you will take [[wound|damage]]. Alternatively, you can push the minecart whilst it's still in motion (although it's unclear how one can bend [[physics]] so as to push a moving minecart whilst inside the minecart). If you push it in the same direction you are already travelling in, you will greatly increase the minecart's velocity. You can also push it in different directions, and this will cause it to gradually change direction-the amount of pushes this requires depends on the minecart's velocity. Once the minecart has stopped moving, you may move out of it safely, or you may want to give it another push. Note that if you push a minecart right after having ridden it (still on the same tile as the minecart), it will act as though you chose to ''ride'' it.

If you want to test this out without creating an adventurer, the [[object testing arena]] allows you to spawn minecarts ({{k|k}}-{{k|c}}-{{k|n}})

== Forging and Melting ==
* Metal minecarts cost '''two''' [[metal]] bars to forge, or '''six''' [[adamantine]] wafers.
* When a non-adamantine metal minecart is melted down, it will return '''1.8''' metal bars, for an '''efficiency of 90%'''.
* When an adamantine minecart is melted down, it will produce '''1.8''' wafers, for an '''efficiency of 30%'''.

== See also ==
* [http://www.bay12forums.com/smf/index.php?topic=109460.0 The "How Does Minecart" Thread] by '''Girlinhat''' et al.
* [http://www.bay12forums.com/smf/index.php?topic=112831.0 SCIENCE: Quantifying minecart physics] by '''Snaake''' et al.
* [http://www.bay12forums.com/smf/index.php?topic=129676.0 How to build a Multi-cart Ore to Magma Minecart Project without needing power] by '''WanderingKid'''.
* [http://www.bay12forums.com/smf/index.php?topic=144328.0 My very own Minecart Education Thread. Ten Lessons, now complete.] by '''Larix'''.

== Bugs ==
*A dwarf will drop her [[child|baby]], if she has one, when boarding a minecart set to be ridden.
*Dwarves have no concept of traffic safety and will walk into busy minecart lines to retrieve objects, often with deadly consequences. This is especially problematic in [[Swimming#Minecart_training|clever applications]] depending on dwarves riding the carts very frequently, because they have a bad habit of dumping their worn clothes on the tracks after a minecart ride. Adding an automatically-operated [[hatch cover]] at the end of such a ride can help prevent [[unfortunate accident]]s.
*Dwarves cannot guide a minecart through an unlocked door unless another dwarf opens the door.{{bug|6056}}
*It is possible for a creature and minecart moving towards each other to pass without collision if they exchange tiles in the same tick.
*After a minecart ride, a dwarf will sometimes haul the minecart to a storage stockpile, leaving another dwarf to haul the vehicle back to the route.
*Minecarts falling onto a floor injure creatures in the tile below the floor.{{bug|6068}}
*A minecart's initial velocity is not affected by weight, when pushed or launched from rollers.{{bug|6296}}
*Removing a stop that has a vehicle waiting on it may cause the game to crash.{{bug|5980}}

{{Category|Fortress mode}}
{{Category|Interface}}

[[ru:Minecart]]

Minecart

2015-06-21T01:46:40Z

NW Kohaku: /* Physics */ Sub-tile positions

{{Quality|Masterwork|08:15, 19 May 2015 (UTC)}}
{{av}}
A '''minecart''' is a [[tool]] intended for [[hauling]], introduced in version 0.34.08. It can be made of [[wood]] at a [[carpenter's workshop]] or [[metal]] at a [[metalsmith's forge]] (using the [[Metal crafter|metalcrafting]] labor.) Minecarts store up to five times as many items as [[wheelbarrow]]s and are quite a bit faster than dwarves hauling objects by hand, but have the disadvantages of requiring a dedicated track network, a complex route planning phase, and the possibility of dwarves [[Fun|blundering into the path of carts filled with lead ore]]. Tracks may be carved into stone, or [[Construction|constructed]]; the latter allows above-ground routes, but these are more difficult to set up due to their additional [[building material|material requirements]].

Just like wheelbarrows, minecarts are considered [[item]]s and are stored in a [[furniture]] [[stockpile]]. Despite their five-times-greater capacity, they are only 33% larger than wheelbarrows and are identical in base [[item value|value]] when made from the same [[material]] (the value may differ due to the [[item quality]]). [[thief|Thieves]] or even mischievous animals can steal minecarts, even when they are moving on a track{{cite forum|109460/3289070}}. However, minecarts moving fast enough or being ridden cannot be stolen.

Although most of the utility of minecarts is in [[fortress mode]], an [[adventure mode|adventurer]] can also ride in a minecart. Adventurers can also pick up and relocate minecarts.

The invention of minecarts revolutionized the [[minecart logic|Science of Dwarfputing]] by enabling smaller, faster logic systems to be built.

== Basic Minecart Usage ==
Minecarts can be used to swiftly transport dwarves, [[flow|fluids]], and/or large amounts of items, but before you have a functional minecart there are several preconditions that need to be met. First of all you need an actual minecart, constructed either in a [[carpenter's workshop]] or [[metalsmith's forge]]. For the minecart to be able to move you also need to carve (with {{k|d}} {{k|T}}) or construct (with {{k|b}} {{k|C}} {{k|T}}) a track, which could be as simple as a straight line. Finally you need to construct stops on your track (with {{k|b}} {{k|C}} {{k|S}}) where the minecart will start and stop.

After you have created the stops and assigned a cart to the track, you must create logic routes connecting several stops and designate starting conditions for each stop. This is done with the {{k|h}}auling key. The most basic conditions are how the cart's movement is initiated and in which direction the cart should start moving. Carts can be either be Pushed (a dwarf stands at a stop and gives the cart a single push) or Guided (a dwarf continually pushes the cart forward, guiding it along the track). The [[hauling]] [[labor]] required for pushing and guiding carts is called "Push/Haul Vehicles" and is turned on by default.

To control which items to transport you can add conditions specifying: (1) which kind of items to be loaded, and unloaded, (2) stockpile links to define which stockpile(s) the items should be un/loaded to and from.

===Capacity and weights ===
Minecarts have five times the [[Weight|capacity]] of [[wheelbarrow]]s.

'''Examples of the capacity of one cart'''
{| class="wikitable"
|-
! Item
! Amount
|-
| [[stone]]
| 5
|-
| [[wood|log]]
| 10
|-
| [[block]]/[[bar]]
| 83
|-
| [[Kitchen|prepared meals]]
| 500
|-
| [[Trap_component#Spiked_ball|spiked balls]]
| 500
|-
| [[Weapon#Native_weapons|mace]]
| 625
|-
| [[Weapon#Native_weapons|spears]]
| 1250
|-
| [[cloth]]
| 2500
|}

The weight of the loaded minecart does not affect the initial velocity received from pushing or launching from a roller. However, the load of a minecart ''does'' affect whether a [[pressure plate]] triggers or not, based on the pressure plate's setting.

'''Weights of different carts'''

{| class="wikitable"
|-
! Type of cart
! Empty cart
! Fully loaded (items)
|-
| oaken minecart
| 28Γ
| 378Γ (10 oak logs)
|-
| platinum minecart
| 856Γ
| 10482Γ (83 gold bars)
|}

The weight of a minecart is one twenty-fifth (1/25) the [[density]] of its material in Urists. Because pressure plates can be set to trigger at intervals of 50 Urists, minecarts with weights just under a multiple of 50 are ideal for switching based on whether they're full or empty. The best minecart materials for full/empty switching are as follows:

{| class="wikitable sortable"
|-
! Material !! Minecart weight !! Content weight required to trigger !! Banana roasts required to trigger (for scale)
|-
| [[Bismuth]] (moods only) || 391 || 9 || 15
|-
| [[Brass]] || 342 || 8 || 14
|-
| [[Electrum]] || 596 || 4 || 7
|-
| [[Fine pewter]] || 291 || 9 || 15
|-
| [[Glumprong]] || 48 || 2 || 4
|-
| [[Lay pewter]] || 291 || 9 || 15
|-
| [[Nickel silver]] || 346 || 4 || 7
|-
| [[Tin]] || 291 || 9 || 15
|-
| [[Trifle pewter]] || 291 || 9 || 15
|}

=== Creating tracks ===
Minecart tracks are made up of contiguous track, tracked ramp, or bridge tiles. Track tiles and tracked ramp tiles have a direction or series of directions associated with them. These directions dictate which directions a minecart on a given tile may move from that tile. For example, a Track NE (northeast) tile allows a minecart on it to move either north or east from its present position. Therefore, if you want your minecart to move east along a straight piece of track, then return west using that same track, you would need to use EW tracks so that the cart could travel east initially, then return west over the same track. Excluding designs in which the cart will "jump" tracks via a drop or other ramp, tracks must be valid end to end to work for most looped or straight-track applications. A single east only track tile in your line of east-west tracks will cause any route using the track to fail the moment it tries to go the wrong way over that tile. Minecart tracks can be built in two ways: Engraved/carved or constructed. A given minecart track need not use engraved or constructed elements exclusively, as the two methods can be used interchangeably depending on the needs of a given section of track. The way the tracks are built is slightly different between the two, as explained below.

====Simple tracks====

'''Carved'''

A single-tile wide strip of natural stone can be designated to be [[Engraver|carved]] (with {{K|d}} {{k|T}}), which will create a straight two-way track. The creation of corners, crossings, and T-junctions is as simple as designating another strip of track that overlaps an existent or newly designated track. Engraved tracks are removed by [[smoothing]] the rock they're on, which results in a smooth floor (that can be re-engraved if necessary), or by building a [[floor]] on top and subsequently removing it. Dwarves can carve corner tracks in one pass by designating the track carving twice and canceling unwanted carvings (with {{K|d}} {{K|x}}). Tracks can be engraved in any natural floor tile, rough, smooth and even over engravings, providing an easy method to remove low-quality or undesired floor engravings. Once a track has been engraved, it's important to check the track directions for each tile in the route carefully to make sure no mistakes were made by yourself or the game's track engraving logic.

'''Constructed'''

Tracks can also be built as regular [[construction]]s (through {{K|b}} {{K|C}} {{K|T}}). This method is resource-expensive, since each track tile requires one stone, [[bar]], or [[block]] for construction, and time-consuming, since you can't designate strips longer than 10 tiles at a time. Corners, crossings, T-junctions, and ramps also have to be designated individually. However, it is usually the only way to build tracks above ground or on soil (barring the [[Obsidian farming|creation of obsidian]]). Constructed tracks are designated for removal like any regular construction; be aware that removing track ramps built on top of natural ones will also remove the original ramp, leaving a flat floor.

====Ramps====

'''Carved'''

The carving of natural ramps is a little more confusing: to carve a two-way track on a ramp (natural only, does not work on constructed ramps), you must designate the track '''starting on the ramp and one square beyond''' in the direction you want the track to go. For the side of the ramp square you want to head upward, there '''must''' be either a natural or constructed wall in the square next to it, otherwise the game assumes you are trying to carve it on the same level -- this can result in the track being carved underneath a door or other object. If you have accidentally done this, you can correct it by smoothing the ramp and constructing a single square of wall next to it, then re-carving the ramp correctly. (However, the wall must stay there permanently; removing it will disconnect the track.)

'''Constructed'''

When constructing track ramps, the stated direction should be the same as the connected tracks. For example, a track going up from West to East would require, starting from the West, a Track (EW), a Track/Ramp (EW) and a Wall behind the ramp, underneath the section of track above it. Incorrectly placed ramps result in minecarts ignoring the ramp and crashing into the supporting wall. They will not, however, display as unusable as when the supporting wall is missing.

'''Examples of ramps'''

A simple ramp would look like this:
{{diagram|spaces=yes|\
z +0 z +1
░░░░ ░░░░
═▲o ░▼═
░░░░ ░░░░
o : wall
}}

Carving track corners into ramps is rather unintuitive and complicated. Since engraving tracks always requires two tiles to connect in a straight line as input, you have to give two separate designations for a single job: a track bit from the ramp tile to the "below" direction and another one to the wall of the "upward" direction. If you wanted to change direction on a ramp from east to north:
{{diagram|spaces=yes|\
z +0 z +1
░░░░░ ░░░░░
░░░░░ ══╗░░
=▲░░ ░░▼░░
░░░░░ ░░░░░
}}
you would need to connect the ramp on z +0 both to the west and to the north by issuing two "carve track" commands, one selecting the ramp and the track tile to the west, and another connecting the ramp tile with the wall to the north. An engraver would then carve a NW track corner into the ramp, allowing carts to pass the corner correctly both going up and down. Such track corners are perfectly serviceable for guided carts, but moving down a route of several of them by pushed or ridden cart is problematic - ramps on corners behave very counter-intuitively, resulting in loss of speed when going down and diagonal movement when going up.

Moving to and from ramps (or between ramps "pointing" in different directions0 causes some non-trivial adjustments to speed and even moving along the tiles at a fixed speed ''unrelated to the entry/exit velocity values'', because transitions to/from ramps are processed differently and are not to be "skipped". This affects compact track/ramp combinations (such as e.g. a simple 2x2 ramp spiral) most, and combined with bouncing often makes them work not in the way one could expect. {{cite forum|144328/5705102}}

{{anchor|Tracks}}

=== Hauling route ===
A hauling route is a list of directions describing how and under what conditions a minecart will move. The proper setting up of routes is essential for a working rail system. Routes, stops, departure conditions and stockpile links are managed from the {{k|h}}auling menu.

==== Route ====
A route defines the path a minecart will take along a track, as well as under what conditions it will move or stop moving. A route is made up of stops. Stops are precisely what they sound like, a position on the track at which you want a minecart to stop. A minecart track might use as little as a single stop for a looped track, which will serve as both a starting and stopping point for the cart, or it could contain many stops, perhaps to load supplies or wait for a bridge to be manually lowered, before reaching its destination or returning to its starting point. It is important to note that you only need to place stops on a route where you actually want the cart to stop and wait for some action to occur. They are not needed to help navigate the cart along the track beyond telling it where on the track to stop.

New routes are created with the {{k|h}}auling key. Existing ones can be removed (without confirmation) with the {{k|x}} key, and also {{k|n}}icknamed. Before operating, the route must have a {{k|v}}ehicle assigned to it (this can be done with either the route or a stop selected). Assigning a full minecart to a route may result in a slow hauling job if the contents are heavy.

==== Stops ====
Stops are the individual waypoints that make up a hauling route. A given stop consists of the location of a tile, as well as conditions describing when, where, and how a cart should be moved after being stopped at that tile. Stops can be created from within the {{k|h}}auling menu, by placing the cursor over a tile and hitting {{k|s}} while highlighting the route (or a stop within) you've already designated. A minecart will begin its route at the first stop created, and continue through each subsequent stop, being guided, pushed, or ridden from each stop to the next depending on the conditions specified. In many basic minecart applications, the cart will end up at the same stop it began at, though this is not always the case. It is important to note that hauling stop order is enforced, even if there is no track. A dwarf will drag the cart overland back to a skipped stop in the route's list if your tracks bypass it somehow.

Once a stop has been placed, it is given a default set of conditions under which to move the minecart if it is stopped there. Each new stop gets the same default conditions regardless of the track it is placed upon (e.g. guide the cart to the north). For this reason new stops might get marked by yellow exclamation marks ({{DFtext|!|#ff0}}) due to invalid directions. One important thing to note is that as you place additional stops, the display will show paths between the stops you have defined. However, this is '''not''' necessarily the actual route the minecart will take once the route is in operation. For example, if a route were defined with two stops at opposite ends of a track with many twists and turns, a line will be drawn directly between those stops to show the order in which they will be visited. These route lines may crisscross all over the tracks, but so long as the track is valid end to end, the cart will follow the track from one stop to the next, even across twists, turns, and z-level changes. Stops, which are the steps that make up a route, should not be confused with Track Stops, described below.

===== Stockpile links =====
By placing the cursor on top of a stockpile and using {{k|s}}, you can create stockpile links while defining a hauling stop. Links can also be redefined by selecting them, placing the cursor over a different stockpile, and pressing {{k|p}}. The cart will then be filled by items present in its various linked stockpiles in preference to other items. Note that bins should be used with caution in stockpiles that are linked to minecarts. Bins cause problems when used with the "Desired Items" list in a stop's conditions. For example, if a minecart is set to accept only granite blocks, and to depart north when it is 100% full of granite blocks, it will not depart if any of those granite blocks are in bins, even if bins are also included in the desired items list. Two solutions to this problem exist as of v0.40.24. First, bins can be disallowed in stockpiles that are linked to stops. Alternatively, bins '''can''' be used in conjunction with minecarts provided that the minecart's departure conditions use only "any items" instead of "desired items." This option can be toggled in the advanced conditions menu for a stop, accessible via the {{key|C|}} key. The cart's contents can still be controlled by specifying what items are allowed in the linked stockpile.

===== Departure condition =====
Departure conditions involve setting conditions in which the minecart will leave on the route. Each condition includes:
# A departure mode (Guide, Ride or Push).
# An initial departure direction (NSEW). Note that this defines the initial direction of movement only. Even if a track includes many turns, as long as the initial movement direction is valid the cart will follow the minecart track thereafter.
# A timer, before which the departure condition cannot be met.
# Conditions on the amount of items in the cart.
Departure conditions are created with the {{k|n}} key. A new departure condition will read: "guide north immediately when empty of desired items". This condition can be changed between basic presets with {{k|c}}. "Advanced" mode ({{k|C}}) allows for more precise control over departure conditions: fine tuning the percentage from 0 to 100 in 25% steps ({{k|f}} and {{k|F}}), switching it being either the maximum or the minimum amount of items for the condition to be met ({{k|m}}), and whether the cart accepts all or only a specific set of items ({{k|l}}). Common to both screens are the departure mode ({{k|p}}, Push, Ride or Guide), {{k|d}}irection, and timer ({{k|t}} and {{k|T}}) options.

To have a cart only carry a specific set of items, the stop can be set to only carry "desired" items, opening the selection screen with the {{k|Enter}} key while having said stop condition selected, and toggling as desired, or it can simply be linked to a stockpile and set to depart once it is full of items from its linked stockpiles, regardless of type.

=== Track Stops ===
A Track Stop, not to be confused with a route stop, is an optional, single-tile construction which serves two purposes. First, it can be used to cancel a cart's momentum in order to slow or stop it as it passes over the Track Stop. This might be necessary if a cart were pushed down a series of ramps to its destination. Second, a Track Stop can cause a cart to automatically dump its contents as it passes over the Track Stop. Track Stops are constructed via {{k|b}} {{k|C}} {{k|S}}, and must be constructed atop an existing piece of track. If a Track Stop has been set to automatically dump a cart's contents, the cart will dump its contents in the direction indicated when it passes over the Track Stop. Depending on the friction settings chosen for the Track Stop, the cart might then stop after dumping, or it might continue on its route to another destination.

Track Stops are not mandatory; in fact, their main use is in automated rail systems. However, even in basic rail systems it can be useful to set a Track Stop to dump items: this saves time that dwarves would otherwise spend in removing items from the cart, time that is better spent driving the cart back to where it's needed. Dumping will occur even with a guided cart. '''Take care not to set Track Stops at a loading site to dump their contents''', or dwarves will never be able to fill the cart. It will dump any contents the moment they are loaded.

Counter-intuitive to their construction method, Track Stops are considered [[building]]s and must be removed by {{k|q}} {{k|x}}.
* See [[#More_on_Track_stop |More on Track Stops]]

=== Step-by-step tutorial ===

Let's construct a simple minecart route. This route will move stone blocks from an input stockpile to an output stockpile. We'll begin by creating the stockpiles:

[[File:minecart-example-1.png|Stockpiles designated.]]

The input stockpile is on the left; the output stockpile is on the right. We'll be moving blocks from left to right. Disable bins in both stockpiles, and set the input stockpile to accept only from links. Then make the stockpile take from the mason's workshop where the blocks are being produced.

Next, carve the track:

[[File:minecart-example-2.png|Track carving designation.]]

Note that the ends of the designation are uniquely shaped; this is automatic, and not anything you need to control. Now, wait for your engravers to come along and carve the track into the stone. (Your haulers will probably also fill up the input stockpile while you wait.)

In addition, while we're waiting for that to happen, we'll build an iron minecart in the forge.

[[File:minecart-example-3.png|Track carved.]]

When the track has been carved, it will look like the above (the track will be solid instead of flashing). Now, order a track stop to be constructed next to the output stockpile:

{|
| [[File:minecart-example-4.png|Track stop designation.]]
| [[File:minecart-example-5.png|Select dumping direction.]]
|}

You must press {{k|d}} three times to select the dumping direction ''before'' placing the track stop. We want our blocks to be dumped into the output stockpile east of the track stop. Then wait for a mechanic to come along and build the track stop.

[[File:minecart-example-6.png|Track stop constructed.]]

Now we'll define the actual ''route''. This is done in the {{k|h}}auling menu. Press {{k|r}} to begin defining a route. Next, move the cursor to the input end of the track, and then press {{k|s}} to define the first stop:

{|
| [[File:minecart-example-7.png|Stop 1 designation.]]
| [[File:minecart-example-8.png|Route definition, in progress.]]
|}

Move the cursor again, to the output end of the track, and press {{k|s}} again to define the second stop:

{|
| [[File:minecart-example-9.png|Stop 2 designation.]]
| [[File:minecart-example-10.png|Route definition, two stops.]]
|-
|
| [[File:minecart-example-11.png|Stops are not defined yet.]]
|}

There are several user interface features to note at this point. The stops have been positioned, but they haven't been ''defined'' yet, so there is a warning {{DFtext|!|#ff0}} symbol by each of them. In the lower right corner, we see what the {{DFtext|!|#ff0}} means. Also, note that the second stop is labeled in white, while the other two lines are grey. The white text is a selection indicator, and can be moved up and down by pressing {{k|+}}/{{k|-}}.

Next we need to define what our stops do. We want the minecart to be filled with blocks at the first stop, then travel to the second stop where it will dump its cargo, and then return. Press {{k|-}} to move the selection up to stop 1, and {{k|Enter}} to open it up. By default, the stop has three conditions:

[[File:minecart-example-12.png|Default stop definition.]]

We don't want any of these, so press {{k|x}} three times to delete them. This leaves us with a blank stop. Now we can add the conditions we actually want. Press {{k|n}} to begin adding the first condition, then {{k|d}} twice to change the direction from north to east. Then press {{k|c}} to change the condition from empty to full. This will instruct the minecart to be guided east when full of desired items.

To set the desired items, we create a stockpile link. Press {{k|s}}, then move the cursor to the input stockpile, then press {{k|p}} to select that stockpile. Now press {{k|Enter}}; this opens up a selection screen that resembles the stockpile customization screen. Move down to Blocks, {{k|e}}nable them, then (if you wish) restrict it to stone blocks.

When you've done all that, stop 1 should look like this:

[[File:minecart-example-13.png|Stop 1, defined.]]

Stop 2 is much simpler. All we need to do is have the minecart return to the input stop. So, make a condition and change the direction:

[[File:minecart-example-14.png|Stop 2, defined.]]

Finally, we just have to assign our minecart. Go back to the route definition screen, and press {{k|v}}. Select the minecart, and press {{k|Enter}}.

Now we've got everything set up:

[[File:minecart-example-15.png|Route, fully defined.]]

The V is red because the minecart hasn't been moved onto the track yet. Some dwarf will have to haul it from the forge to the first stop, by hand; this will take a while, especially if the forge is far away.

Once the minecart is in place, dwarves should fill it with blocks from the input stockpile, which will in turn be filled with blocks from the workshop where your mason has been toiling dutifully. When the minecart is full, the blocks will be dumped into the 1x1 stockpile on the right. Automatic quantum dumping!

=== Troubleshooting ===

Because of the complexity of the system, all but the most careful and experienced minecart users will encounter issues. Most route issues can be diagnosed and fixed from the {{k|h}}auling menu.

'''Symptom:''' {{DFtext|! Set dir/connect track|6:1}} message appears to the right of one or more stops

'''Possible Causes:'''
* The departure direction of the stop might be invalid. Edit the stop using {{k|Enter}} and press{{k|d}} until it is pointing in a valid direction.
* The track stop might not be built on top of a track. The track stop must be deconstructed to remedy this issue.
* Your track might not be built correctly. Make sure all connected tracks between destinations are not one-way tracks.
** This can be especially confusing with ramps. To carve a two-way track on a (natural) ramp, you must designate the ramp and one square beyond in the direction you want the track to go.
** Ramps '''must''' have a solid block on the side opposite to the track, or they will neither work nor be marked as "unusable". The solid block can be natural or constructed.
* The desired/kept items might not be configured correctly.

'''Symptom:''' The status '''0% V''' always appears to the right of one stop.

'''Possible Causes:'''
* The stop may not be set to take from a stockpile. Edit the Stop using {{k|Enter}} and make sure you see a message like "Take from Stockpile #1".
* The take conditions must correspond with the contents of the stockpile.
* The track stop may be set to dump. A track stop set to dump cannot be filled. You must either set the stop to a time-based departure or deconstruct the track stop and rebuild it without dumping. (Alternatively, with [[DFHack]] you can modify "Dump on arrival" to "No" using the {{key|q}} menu without rebuilding the stop.)
* Make sure the minecart itself has not been designated to be dumped (such as when using mass-dump).

'''Symptom:''' Dwarves fill the minecart properly, but will not move it thereafter.

'''Possible Causes:'''
* The minecart may contain items which are not included in its current stop's desired items. Check inside the minecart using the {{key|k}} and {{key|z}} keys and ensure that all items in the cart are desired items.
* The minecart may contain desired items in bins. Minecarts seem to have problems realizing that they are in fact full of desired items if some of those items are in bins, even if bins are also among the desired items for that stop. '''This cannot be solved by adding the appropriate bins to the stop's desired items.''' Either disallow bins in stockpiles you intend to load minecarts from, or set the departure conditions to rely only on percentage of total load rather than percentage of desired items using the advanced conditions menu ({{key|C}} key).

'''Symptom:''' Dwarves repeatedly attempt to load the minecart, but no items are ever loaded into it.

'''Possible Causes:'''
* This can be caused by using a Track Stop with autodumping enabled at a loading site. Every time a dwarf places an item into a cart resting on such a track stop, the item will be immediately dumped, causing unlimited, useless cart loading jobs. Autodumping Track Stops should never be used at a loading site.

'''Symptom:''' A dwarf picks up the minecart and carries it to its destination.
* See [[#Quirks|Quirks]]

=== Danger ===
Minecarts are not without <strike>danger</strike> [[fun]]. Although designating a track automatically sets the [[traffic]] designation to low, dwarves ''may'' still walk on them, and [[creature]]s ignore traffic designations altogether. If an unlucky dwarf or creature fails to [[dodger|dodge]] a minecart, they can be injured. Most of this danger can be avoided by setting the minecart {{k|h}}auling commands to guide instead of push or ride (dwarves guiding minecarts will ignore traffic restrictions), as well as by [[pasture|pasturing]] domestic animals and preventing the access of other creatures to the tracks. Note that removing the track doesn't reset that tile back to normal traffic priority, so you may wish to manually clean up traffic designation afterward. Also note that bridges that are used as tracks don't have their traffic priority changed automatically (since they're just normal bridges), which could cause dwarves to pathfind normally through dangerous minecart entrances in your fort's walls if you're not careful.

The only <s>fool</s>''dwarf''-proof method is to make the tracks inaccessible. There are several ways to create a track which works for minecarts but doesn't allow creature-traversal; the simplest is perhaps building a [[statue]] on the tracks. Other options include adding single-tile holes (minecarts moving at reasonable speed will jump the gap), vertical drops, minecart-triggered doors, small pools of liquid (4/7 water or 2/7 magma), and hostile creatures overlooking the tracks. For safety, both ends of the track should be isolated, making the dangerous center sections completely inaccessible (though maintenance access can be provided by a locked door).

Danger does not always involve living victims: careless route designation can also result in minecarts careening off tracks or colliding with each other. If this occurs, the [[item]]s may be scattered; this can cause even more hauling jobs than the minecart aimed to eliminate. Even <s>better</s> worse, scattered items, especially [[weapon]]s, can injure passing [[dwarf|dwarves]] or other [[creature]]s; in the words of Toady One the Great, "Accidental grapeshotting of the dining room should be possible now."

Of course, the danger of using minecarts means they can also be [[Trap_design#Minecarts|used as weapons]] by imaginative players.

== Advanced usage and automation ==
Minecart-specific effects are implemented via track stops, rollers and [[pressure plate]]s with "track" condition set. Since all three are considered [[building]]s, they can't be built on the same square (however convenient track stop + pressure plate would be) nor a simple ramp, and are removed by {{k|q}} {{k|x}}.

=== More on Track stop ===
Track stops are constructions that allow further automation of minecart systems via adjustable features such as braking by friction and automatic dumping of contents. They can be built from logs, bars and blocks through {{K|b}} {{K|C}} {{K|S}}; friction amount, dumping toggle and dumping direction must be set '''before''' construction, and these settings can be neither changed nor seen thereafter; however, track stops can be linked to [[pressure plate]]s or [[lever]]s to toggle friction and dumping On or Off (trigger state is inverted: switch On = track stop Off).

If a [[stockpile]] is placed on the tile that a track stop is set to dump to, it can act as a [[Exploit#Quantum_stockpiles|quantum stockpile]] and any items dumped from a minecart that match the storage settings of the stockpile will remain there and accumulate. Normally trackstops are built on top of existing track to operate on moving minecarts, but they can also be used without tracks to create [[Exploit#The_Minecart_Stop|automatic quantum stockpiles]] (see also [[#Step-by-step_tutorial|step-by-step tutorial]]). It is not always desirable to collect ALL of certain items into one quantum stockpile, such as when distributing a material to multiple separate industries. You can link your quantum stockpile to various other stockpiles, ensuring that your dwarves will keep them supplied as necessary. Because quantum stockpiles never fill up like regular stockpiles, it may be a good idea to add a switch to turn them off.

Items dumped from a minecart at a track stop (or dumped by any other means) into open space fall through z-levels until they land on a solid surface. Items falling onto a designated [[stockpile]] will automatically be considered part of that stockpile, even if the stockpile is set to disallow those items (they will, however, be automatically moved to a more appropriate stockpile, if available). Items falling on top of a minecart will '''not''' fall "inside" the minecart. Use with caution; dwarves have fragile skulls.{{bug|5945}}

=== Automated propulsion ===
==== Roller ====
{{Main|Roller}}

A '''roller''' is a [[power]]ed [[machine component]] for the automated propulsion of minecarts. They are built over the top of existing tracks with {{K|b|M|r}}, requiring a [[mechanic]], ''(length/4)+1'' [[mechanism]]s and a [[rope]]. Rollers may also be placed directly on ramps to help pull carts up Z levels. Rollers are very useful to maintain a cart's momentum along long routes, to get them to climb Z-levels without dwarfpower involved, and to get them to reach speeds unattainable by guiding dwarves. These devices are variable-length (1-10), variable-direction and variable-speed ([[Minecart#Numbers_behind_the_scene|see below]]), all traits that can be set at construction time; a roller uses two units of power per tile it is long.

Single-tile rollers transfer power in all four cardinal directions, while other rollers generally only transfer power perpendicular to their activity direction. Longer rollers can also transfer power along their activity direction if built in the correct order, although this can be hard to accomplish and is easily broken. Rollers cannot be powered from above.

Rollers have great acceleration and capped speed. Carts going faster than the roller are unaffected. If a cart moves across an active roller in the direction the roller works and moves slower than the roller's specified speed, the cart will be set to the roller's speed. A cart going against a roller's movement direction will be sent back the way it came (once again at the roller's speed), unless it was moving extremely fast: speed increment of 100000 allows to reverse carts from the full "highest" (50000) speed roller to full "highest" speed back, but ramps can accelerate a cart beyond this. {{cite forum|144328/5702453}}
A cart crossing over a roller perpendicular to its current movement direction will gain the roller's amount of speed in the perpendicular direction without directly changing its forward motion. Without an adjacent wall to constrict its movement, this will typically send a cart off the rails on a diagonal path, completely unable to follow any tracks until it collides with a wall or is otherwise brought to rest. However, if the roller is placed over a track turn and pushes ''from'' the direction of that turn's track, the turn affects carts ''after'' the roller, so they will be forced into the turn rather than derailed in a diagonal direction. {{cite forum|144328/5702453}}

{{diagram|spaces=yes|\
tracks: full:
║ ║
═╗═ ═╢═
║ ║

╢ : roller pushing from W to E
}}
If the roller is powered, carts from ''all'' directions (unless too fast) exit S, because speed imparted by the roller forces carts toward E and ''then'' into the turn.
If not powered, carts from W and N exit S, carts from E and S exit W. Carts above derail speed will ignore the turn, of course.

{{diagram|spaces=yes|\
║ ║
═╗═ ═╟═
║ ║

╟ : Roller pushing from E to W
}}
Carts from the E or W: exit W.
Carts from N: derailed diagonally, exit SW.
Carts from S: derailed diagonally, exit NW.

Rollers affects carts on a track - if placed on a floor or ramp without any tracks, they are ignored. Depowered rollers are also ignored, friction is determined by the tiles underneath.

Because of their one-way nature, rollers are unsuitable for most two-way minecart tracks (unless you set gears toggling roller A->B off while toggling A<-B rollers on). However, a minecart set to be ''guided'' is not affected by rollers at all{{cite forum|109460/3286235}} — this allows a one-way track to be used in both directions. In addition, unpowered rollers do not affect minecarts.

Care must be taken in [[glacier]]s and other extremely cold [[biome]]s, since rollers (and the machinery used to power them) will not operate when constructed on natural [[ice]] floors.

==== Impulse ramps ====
Carts can be given momentum without rollers or changing z-level through a phenomenon called "impulse ramps". A track ramp which is connected both to a wall and to a floor will ''always'' accelerate a cart towards the connected floor tile, no matter where the cart enters the tile from. This means carts can be accelerated as though dropping z-levels, even if the cart doesn't actually change z-level at all. If a track ramp faces three directions such as ╩, then two of those directions need to be facing walls for the cart to be accelerated towards the remaining direction.

Example of straight impulse acceleration:

{{diagram|spaces=yes|\
▒▒▒▒▒▒▒▒▒▒ ▒▒▒▒▒▒▒▒▒▒
═▲▲▲▲▲▲▲▲▲▲═ ═╚╚╚╚╚╚╚╚╚╚═
▒ : Wall
═ : Normal track
▲/╚ : N/E Track/Ramp
}}

If a cart enters from the left, it will speed up on every track/ramp and exit to the right going very very fast - more than one tile every step. If it enters from the right then it will bounce back impulsed by the ramp if it's going slow enough.

As another oddity, carts coming from ramps will in some cases "teleport" through most of the next tile. This is called the "checkpoint effect", and is explained in detail in the Physics section, below. This negates the deceleration of the next tile if it is a ramp "angled" in a different direction. You can just make an upward spiral alternating impulse ramps and regular upward ramps. It takes no power, is quick and cheap to build, requiring only channeling and track carving, and the cart goes up fast, but not so fast that it launches its contents.

Example of an impulse elevator:

{{diagram|spaces=yes|\
z +0 z +1 z +2 z +3
░░░░░ ░░░░░ ░░░░░ ░░░░░
░╔░░░ ░▼╚╗░ ░░▼▼░ ░░░░░
░╝░░░ ░▼░░░ ░░░╔░ ░░░▼░
░▼▼░░ ░░░░░ ░░░╝░ ░╚╗▼░
░░░░░ ░░░░░ ░░░░░ ░░░░░

░ : Wall
╔,╚,╗,╝ : Track/Ramp
▼ : Down Ramp (empty space)
}}

Note that this impulse elevator, due to the checkpoint effect and upward curved ramp effect, will not actually result in carts traveling straight up the ramp. They will lose speed, bounce off a ramp, then be accelerated back into the spiral after a 9-turn delay on both tiles on the floor where they are stopped. This is because the checkpoint effect allows carts to travel up the ramps in a single turn, but also prevents the impulse ramps from adding acceleration unless the cart is slowed to staying on the ramp for more than one turn. Initial acceleration will carry the cart up a variable number of floors before this effect occurs, but this bouncing back and forth will occur every 5 z-levels after the first time the cart stops. When the cart ''is'' traveling upwards, it will pass every tile at a rate of one tile per turn regardless of its actual speed, due to the checkpoint effect. In tracks with only a single cart, this is negligible, but when multiple carts are on the same track (such as when you place multiple carts on a magma cart lift) this can cause collisions which derail carts or cause other unexpected or undesired behaviors.

The following impulse ramp (while larger) should alleviate these problems by using a straight ramp to go upwards, preceded by an impulse ramp to exploit the checkpoint effect and negate up ramp costs. Corners still decelerate carts, so the cart will tend towards a velocity of 72k, which is derail speed. Derail speed breaks (see Controlling Speed, below) may be necessary at the top.

{{diagram|spaces=yes|\
z +0 z +1 z +2 z +3
░░░░░░ ░░░░░░ ░░░░░░ ░░░░░░
░░░░░░ ░╔╔═░░ ░░▼▼╗░ ░░░░░░
░║░░░░ ░▼░░░░ ░░░░╗░ ░░░░▼░
░╚░░░░ ░▼░░░░ ░░░░║░ ░░░░▼░
░╚▼▼░░ ░░░░░░ ░░░░░░ ░░═╝╝░
░░░░░░ ░░░░░░ ░░░░░░ ░░░░░░

░ : Wall
║,═,╔,╚,╗,╝ : Track/Ramp
▼ : Down Ramp (empty space)
}}

Also, if you want to have a cart following a below-derail speed, the following track works well:
{{diagram|spaces=yes|\
z +0 z +1 z +2 z +3
░░░░░ ░░░░░ ░░░░░ ░░░░░
░░░░░ ░══░░ ░▼▼║░ ░░░▼░
░║░░░ ░▼░░░ ░░░║░ ░░░▼░
░║▼▼░ ░▼░░░ ░░░░░ ░░══░
░░░░░ ░░░░░ ░░░░░ ░░░░░

░ : Wall
║,═ : Track/Ramp
▼ : Down Ramp (empty space)
}}
In this elevator, the cart collides with the walls in the corners, but then realigns on the ramp, picks up speed, checkpoints through the next ramp, and slams into the next wall. It is slower (10 ticks per floor) but produces reliable speeds, and will exit the impulse elevator at little more than push speeds.

A sort of opposite effect to impulse ramps also exists: ramps lacking the proper "up" and "down" connections are treated as flat track, even if they actually go up or down z-levels. This allows building "anti-impulse" slopes consisting entirely of ramps only connected up, which a minecart can travel up forty levels and more, needing no more than a single push.

=== Controlling traffic ===

==== Switching ====

As constructions or tile features, [[door]]s and other furniture can be built on tracks. A [[door]] or [[floodgate]] can be turned on or off by a [[lever]], effectively controlling the flow of automated minecarts. This may be <s>dangerous</s> [[fun]], however.
{{diagram|spaces=yes|\
->
A ════┤≡════ B
┤ : roller pushing to East
≡ : door
}}
The roller pushes the cart east, but until the "departure condition" is fulfilled, the door remains closed and blocks the path.

[[Bridge]]s can also act as tracks, but only if they're lowered or not retracted. This property can enable levers to turn tracks on and off. However, care should be taken to ensure that such bridges are never operated while a cart is on top of them, as the cart will be flung off the track. It's worth noting that it's often faster, and cheaper, to construct large bridges than long sections of constructed track.

A powered track switch can be constructed by building an "inverted" corner as illustrated below.
{{diagram|spaces=yes|\
B B
║ -> ║
║ ║
════╚═══ ════├════
A C A C
├ : roller pushing to West.
}}

If the cart is pushed East from the stop at 'A' while the roller is activated, it will arrive at 'B'. If the roller is not running, it will arrive at 'C'. The switch works by the roller first reversing the incoming cart's movement and the cart ''then'' following the track corner.

This switch is very reliable, reacts instantly to on/off signals, and carts of any speed can be switched by this design, although very fast carts will require rollers that are several tiles long, up to three. The requirement for power can be inconvenient or impractical. Non-powered solutions may use controlled derailment, or a connecting bridge.
{{diagram|spaces=yes|\
B ╥
║
║
╞════╝ ════╡
A D C
}}
Here the track between A and C is not continuous. The only continuous track is A->B, with a corner (not a T section). Fast moving carts will tend to derail at D and rejoin the track to C. Placing a door at D will prevent the derailment, so the cart continues to B. The door is operated by mechanisms elsewhere (typically, a lever, but some fun can be had with pressure plates).

Since it depends on derailing, this switch requires a very fast cart, faster than what can be achieved with rollers alone. To gain sufficient speed, a cart must be accelerated further, usually by descending several levels or through impulse ramps. The high speed makes the cart much more dangerous and harder to control.

If carts are moving too slowly to derail at the corner, a retractable bridge may be used as a connector between A and C.
{{diagram|spaces=yes|\
B╥
║
║
A╞════bbb════╡C
}}
The bridge must overlap the corner. Bridges behave like a track crossing, allowing carts to pass in a straight line. When retracted, the corner reappears, so the carts will continue to B. Bridges take 100 steps to react to a signal, necessitating rather long "lead times" when switching tracks via bridge.

As mentioned above, special care must be taken to make sure the bridge doesn't change state while the cart is passing over it. Retracting bridges will throw the cart, causing it to stop dead. Raising bridges can even crush the cart.

==== Controlling Speed ====


Minecarts can reach extremely high speeds, especially when descending multiple Z-levels. A minecart will derail at a track corner if its speed exceeds 0.5 t/st (tiles per step), '''unless''' the route in the direction of travel is blocked:

Will derail at > 0.5 t/st:

{{diagram|spaces=yes|\
in ══╗ -> derailing
║
out
}}

Will not derail at > 0.5 t/st:
{{diagram|spaces=yes|\
in ══╗O
║
out

O : wall/column.
}}

This behavior can be used to build a "speed limiter", that will ensure that when a minecart exits it is traveling below derail speed:
{{diagram|spaces=yes|\
░░░░ ░░░░░ ░░░░░
in ═╔═╗░ ░╔S╗░ ░╔S╗░
out ═╬═╝░ out ═╗═╝░ out ═╗═╝░
░╚S╝░ ░╚═╝═ in ░╚S╝░
░░░░░ ░░░░ ║░░░
in
░ : wall
S : Track Stop (High Friction or lower)
}}
If the minecart is traveling below derailment speed, it will not be affected; if above, will be slowed down and checked again. Granted, you could do the same just with track turns, but it may take a lot of turns and time.

Since all the derailings, bounces and ramps can impart a sideway component of speed small enough to start visible drift many tiles away (say, [[Fun|in the middle of a bridge]]), track turns have one more use: forcing the carts to move strictly along the grid directions. Carts passing a turn below derailing speed convert one component of velocity into another, thus eliminating the drift.

=== Loading liquids ===
[[Water]] and [[magma]] can also be loaded into minecarts by submerging them to a depth of at least 6/7 while standing still or moving at speeds of at most 10000. Loading fluids onto minecarts can be difficult because the added friction provided by fluids can stop a cart in a submerged tile. Curiously, filling a minecart with magma does not injure a dwarf ''riding'' it. A minecart will hold enough fluid to increase the depth of a single tile by 2. This amount is listed as 833 units, which weigh 459Γ (water) or 999Γ (magma). An iron or steel cart filled with magma weighs 1313Γ, while an adamantine cart filled with magma weighs 1007Γ. Since you need a minecart above the liquid's level, possible arrangements may include pressure-activated sluices, rollers (with magma-safe chains for magma), pouring from above to "submerge" it briefly on the same level and drain excess away (dig deeper and leave a vaporizer, though if you could have power for rollers, may as well use a pump) and exploits with ramps (not necessarily impulse ramps, "same height" passing dip does it).
The liquids can be dumped by a constructed track stop.

== Quirks ==
This little quirk concerns dwarf-managed minecarts. If a track which was previously open becomes blocked (ex. flipping a switch connected to a floodgate you've built on the track to raise it) and the conditions for departure are met, instead of refusing to ride/guide the minecart or ride/guide it until it reaches the obstacle, the dwarf will pick up the minecart off the tracks and haul it to its scheduled destination on foot. If the distance is long enough and the weight of the cart heavy enough (due to being filled with heavy items such as stones), the dwarf may drop the cart because of fatigue/hunger/thirst before reaching the destination. This will cancel that vehicle setting job and make another dwarf come by and attempt to haul the cart to the nearest appropriate stockpile where another dwarf will pick up the cart and attempt to haul it to its initial stop. If the stockpile is far enough from initial stop, this second dwarf who is attempting to place the minecart on its tracks may also drop the minecart out of fatigue/hunger/thirst creating a loop that will go on until a dwarf with enough endurance manages to place the minecart where it belongs.

In fact, it seems dwarves are more than happy to attempt to carry a minecart from one stop to another even if just waiting until the track is open again would be the more sane option.

Dwarves will also carry a minecart to its next stop if the direction specified is incorrect (or invalid). This can often occur when using the default departure settings and forgetting to set the direction of each condition.

Dwarves can admire buildings while riding mine carts. Dwarves will not fall asleep during a ride (at least not from being drowsy). If riding on a continuous powered track loop, the dwarf will die of dehydration/starvation as they can not jump off to get sustenance{{cite forum|109460/3377228}}. Dwarves riding in submerged minecarts will gain experience in [[swimming]].{{cite forum|129889}}

Tracks block wagon access to trade depots, unless they're on a ramp. [[Bridge]]s can also be used, as they function as tracks but do not block wagons.

== Physics ==


Minecart physics depend greatly on the departure mode set in the route stop conditions.

When set to "Push" or "Ride", minecarts will move according to the regular laws of momentum, gaining speed when going downhill, losing it slowly due to friction when on a flat plane, and more quickly when going uphill. In these modes, minecarts will move in a straight line until they either are brought to a stop by friction or an obstacle, or until they encounter a turn. A minecart will roll straight past "blocked" ends of T-junctions or track ends, they have no power to restrict a cart's movement. The cart's behavior is largely independent of the weight of its contents (including fluids and dwarves): heavily loaded carts gain more momentum when accelerating, but this only plays a role in collisions: a heavy cart gains just as much speed and is as easy to stop as a light one. In either case, dwarves can not push nor ride an unpowered cart up a ramp, bouncing back the direction it came. At best, this is a waste of time; at worst, it will give your cart-pushing dwarf a [[fun|fun surprise]]. To solve this, the player can either use Rollers (see below) or set the cart to be Guided.

The difference between "Push" and "Ride" is whether the dwarf will go along with the cart or not.
{{DFtext|Push}}: the dwarf will give the cart an initial push, not enough to go up a ramp, but enough to go some way along flat track, and the dwarf will remain at the first stop, ready for a new job.
{{DFtext|Ride}}: the dwarf will give the cart the same initial push and then hop aboard the cart riding with it to the next stop.
{{DFtext|Guide}}: minecarts seem to ignore all laws of physics. That is:
*Ignore the weight of any and all items inside. Therefore:
**Move at the speed of the dwarf that is guiding them. It is thus recommended to pick the most [[attribute#Agility|agile]] of your dwarves for cart-guiding tasks.
*Ignore working rollers.
*Will ''not'' collide with other guided carts even when a full frontal collision would be expected.
*Will go up ramps like nobody's business.
This is therefore the recommended method of transport for simple non-powered rail systems, despite it diverting a dwarf from other, potentially more important tasks.

Some samples with behavior:
{{diagram|spaces=yes|\
A <-> B A <-> C A <-> B
B B B
║ ║ ║
A══╝ A══╩══C A══╬╗
You can only go A->B ╚╝
Works when the cart Works
is in Guide mode.
}}
In the second example above, a cart "pushed" from B will go over the junction and roll off into the unknown south.

=== Sub-tile Positions and Velocity ===
Carts store six values that are unique to them. Three sub-tile position values, and three velocity values. (X, Y, and Z.)

Note that the Z position and velocity only matter when a cart is in flight.

Each non-ramp tile is functionally composed of a value between 0 and 100,000, with a "centered" cart sitting at the 50,000 point in all three directions. When a cart has velocity, it is added or subtracted from the current position every tick, and then a friction force is applied to the cart.

When carts move beyond the maximum or minimum value of a tile, they physically move a tile on the map, and start at the far end of the sub-tile position the next tile. (I.E., traveling West, a cart that starts a tick at 15,000 X sub-tile position and has an X velocity of -20,000 would move to -5000 X sub-tile position, which is out of bounds for that tile. As such, it will travel one tile West, and start the next tick at 95,000 X sub-tile position. It will also lose 10 velocity in that tick due to friction with the track if it is on a track, or 100 velocity if it is on regular ground, or no velocity if it is airborne.)

Ramp tiles are longer, approximately 144,000 in the direction where it "slants downward", (to approximate a 45 degree slope, it is square root of two times longer,) and centered at 72,000. Because of this, a cart with no velocity dropped from a hatch will land at the center of a tile, at position 72,000, and 72,000, and will start rolling in the ramp's "downward" direction, picking up the ramp's acceleration (4890 per tick in the direction of the ramp's "downward" direction) every single tick, then moving that sub-tile amount every tick. When it enters another ramp ''facing the same direction downwards'', a cart will start at the 0 or 144,000 position, and have twice as far to travel. This means that if a cart enters a ramp from the side, it will gain twice the momentum of simply starting at the midpoint of a ramp.

Note that passing from one direction of ramp to another or to flat terrain causes unintuitive behavior, "teleporting" to the midpoint of another tile in what is called the "checkpoint effect", below.

Note, however, that sub-tile positions are carried over from tile-to-tile. This separate tracking of velocity and position between X and Y can lead to problems with diagonal motion:

{{diagram|spaces=yes|\
z0 z-1
▒║▒ ▒▒▒
═▼═ ▒╬▒
▒ ▒ ▒║▒
▒ : Wall
═, ║ : Track
╬ : Track and Ramp
}}

If a cart is passing West-to-East over this setup, the valid ramp to the South will apply "Southward" acceleration to the cart (-Y velocity) as it passes through the ramp tile. Assuming it only spends one tick in that tile, it will still have gained about -5k Y velocity, which will still apply motion Southward. If the tracks continue straight for another 11 tiles, it will have accumulated enough Southward motion to try to move a tile South, even if all tracks are facing East-West.

'''Non-curving tracks do not correct this motion'''.

They don't "tip back over" without adjustments in the track. Any value of sideways motion on tracks larger than 990 will lead to a derailment. (Lower values will be nullified by friction before they are enough to lead to derailment, but there is currently no way to apply such a small amount of velocity.)

If the tile to the South is a wall at that point, it will be considered a collision with a wall that ''halts all motion''. If the tile is open, it will generate a diagonal track derailment that will send a cart flying until it strikes a wall, at which point it will not re-rail itself. In almost any circumstance, this is undesirable behavior.

The only way to appropriately deal with this is to either cancel out this behavior with an equal amount of acceleration in the opposite direction, or to take a curve.

Note, again, that sub-track position is saved in both directions, so when a cart approaches a curve, it will already have a shorter or longer distance past the curve when it makes the turn.

Curves are applied "halfway through" a tile. If a cart is moving East, and approaches a North-East track at 20k velocity, and friction is eliminated for the purposes of a cleaner demonstration, then when it enters the tile at sub-tile point 0 X, and 50k Y at the start of a tick, it will then move 20k East (+X) the next tick, and be at 20k X sub-tile position, and 50k Y sub-tile position. Next tick, it is at 40k X sub-tile position, and 50k Y sub-tile position. The next tick would take it to 60k X, but that's past the halfway point, so it stops at 50k, turns (and thus loses 1k velocity, but translates the rest from X-velocity to Y-velocity) and travels another 10k. It is now at 50k X sub-tile position, and 60k Y sub-tile position. Next tick, it travels at 19k velocity North, and so moves to 50k X sub-tile position, and 79k Y sub-tile position. Then in two more turns, it leaves to the North.

In the case of diagonal motion due to having velocities in X and Y at the same time, it is critical that the direction the cart is heading in reaches that halfway point in a curve before the cart leaves the track off its sideways velocity direction. If it does so, all sideways velocity is lost, as forwards velocity ''overwrites'' sideways velocity in a curve. If, in that example in the paragraph above, the cart entered at 0 X sub-tile position with 20k X velocity, and 40k Y sub-tile position and -1k Y sub-tile position, it would take that "curve" (or rather, redirection of velocity) on the third turn, while it is at 38k Y sub-tile position to start with, and then move to 47k Y sub-tile position at the end of that tick. It would then move to 56k Y sub-tile position in the following turn, and take 3 turns, rather than just 2, to clear the tile.

But, most importantly, it would be centered in the X sub-tile position, and with the negligible difference of an extra tick, all sideways velocity could be safely ignored.

There are two common ways to gain sideways velocity: Rollers facing perpendicular to the cart's travel path (which, as covered above, are almost always a bad idea, as it is easier to push ''against'' the travel direction of a cart into a curve, which redirects all velocity in the new direction,) and corner ramps, which are covered below, and require a curved track to compensate for sideways velocity within a few tiles.

=== Track Direction Irrelevance ===
Carts that are traveling independently, (that is, not guided,) only care that tracks ''are'' on the tile, not which direction the tracks actually move. Tracks respect only curves (with two exits) and ramps.

This means, for example, that the following tracks, when a (non-guided) cart travels from West-to-East, are functionally identical in effect:

{{diagram|spaces=yes|\
A════════════B A╬║╚╔╣╩╦╠╥╨╞╡B
}}

This is because so far as the cart is concerned, only valid ramps and curves with two exits where there is no exit in the path they are traveling matters.

Hence, if a minecart encounters the end of the track or a T junction with no "exit" in its movement direction, it will simply leave the track and continue on its course in a straight line until it encounters an obstacle, slows to a stop, or encounters another track even if the tile at which it joins the new track instantly sends it around a corner.

In fact, a "║", a "╦", a "╬", and a "╥" are ''only different in appearance'', and are ignored by the cart, which will continue in its current direction, regardless of the track. For any purpose but ramps, ''only curves matter at all''.

Carts only check for curves when they are halfway through a tile. When they get there, they look to see if their path has no exit. (That is, if it is traveling East, it checks if there is an East exit.) If there is, it ignores all other track directions, and keeps traveling. If there is not, it checks to see if there are only two exits to the track, and if one of those directions was the direction it "came from". (That is, if traveling from the East, it checks if there is a valid exit to the West, and if so, if there is either a North exit or a South exit.) If there is not, it ignores the track anyway, and keeps on traveling as though it were still on track. If there is, it will subtract 1000 from the velocity of the cart, and redirect all forward velocity to the direction of the curve. This change in the direction of velocity ''overwrites'' any "diagonal" velocity, which can prevent diagonal velocity derailments, but any perpendicular velocity is not preserved, and is instead discarded.

=== Valid and Invalid Ramps ===
Ramps are functionally defined for cart purposes as being a tile which exerts an acceleration force upon its "downward slope", and which allows connection to tracks a z-level above or below. This downward slope requires a cart to have one ''and exactly one'' carved exit to the tile that is the "bottom" of the ramp. Ramps accelerate carts in this "downward" direction (possibly leading to diagonal movement, below), and the deceleration of an "uphill" ramp is actually just the acceleration being applied against the direction of a cart's movement.

This is where players can find an exploit in the behavior of ramps - if there are ''two'' "downhill" exits to a ramp (such as a "T junction" on a ramp where only one exit faces a wall), then the ramp provides no acceleration ''or'' deceleration, allowing carts to travel up ramps without any loss of momentum except for the standard "flat track" deceleration, because as far as the cart is concerned, the track ''is'' flat. (A T junction is also not a curve, so the track is considered flat and straight no matter what direction the cart is traveling.)

Similar effects can be achieved when there are ''no'' "downhill" exits to a ramp. This may be the case if you have, for example, an East-West track with a one-tile channel with a ramp in it. The cart will travel through the "dip" with no change in velocity. It can also be the case if you abuse the Track Direction Irrelevance, above, and set only exits ''up'' the ramp, and none leading ''down'' the ramp. For example, if a cart is traveling from West to East up a slope, only carving East exits on each tile of ramp will make the cart travel up the ramp, and then recognize the tile it is on as being a "flat" tile, thus ignoring any deceleration from traveling uphill.

Note that this effect only reliably occurs at below-derail speeds as the cart will treat the ramp as an invitation for a ramp jump otherwise. (This almost always results in a collision with a wall that will stop forward progress.)

=== Falling ===
When falling, a minecart appears to cause no damage upon collision, possibly to allow cart "stacking" across Z-levels.{{cite devlog|2012|04|06}} A dwarf riding in a minecart that is dropped multiple z-levels suffers normal fall damage. Minecarts can fall through up/down stairs.

While airborne, carts do not feel the effects of friction in any horizontal direction, and will continue until they strike an obstacle. Carts that land on tracks instantly re-rail themselves regardless of track directionality.

Falling carts accelerate similarly to the way that a ramp will accelerate a cart in a special z-only velocity that only applies to airborne carts. (Actually, acceleration due to gravity in freefall seems curiously slightly ''slower'' than ramp acceleration.) Ramp acceleration, while it logically should be partially z-directional, is only recorded as x- or y-directional, and there is no translation of z-directional velocity upon landing. Landing carts zero out their vertical velocity upon landing, even when landing on ramps, although carts that had horizontal momentum while falling preserve it.

This means a cart falling (from a hatch, thus with no horizontal speed) onto a track ramp is accelerated as if starting from the middle of the ramp - i.e. to the same speed, no matter how many Z-levels it was dropped, vertical velocity is negated. {{cite forum|144328/5701211}}

Carts falling onto a floor can, however, cause damage to creatures ''one tile below the floor''. This can be used in an [[exploit]] called a "thumper", where carts are caused to repeatedly fall on a floor above an entrance to the fort, inflicting significant damage (as though it were a collision) on those below the cart.

=== Cart Jumps ===
Carts that cross off of "up" ramps relative to their current direction of travel, which do not have a ceiling above them, are traveling above derail speed, and do not have valid ramp track before them can translate a portion of their horizontal velocity into vertical velocity, causing a cart to be projected into the air until vertical velocity is negated and overcome by the gravitational acceleration. Because downwards acceleration is applied per-tick, this creates a reasonable facsimile of the parabolic motion of an actual object rolled up a ramp and launched with significant speed.

{{diagram|spaces=yes|\
z0 z0 hiding ramps z+1 A z+1 B (hidden ramp)
▒▒▒▒▒▒▒▒▒▒▒▒ ▒▒▒▒▒▒▒▒▒▒▒▒ ▒▒▒▒▒▒▒▒▒▒▒▒ ▒▒▒▒▒▒▒▒▒▒▒▒
═▲▲▲▲▲══▲▒▲═ ═╚╚╚╚╚═══▒══ ▼▼▼▼▼ ▼═▼ ▼▼▼▼▼ ▼╚▼
▒ : Wall
═ : track
▲ : Ramp
}}
In this diagram, if there is no ceiling above it, the track in z+1 A will launch its carts airborne when they travel across the ramp. z+1 B (with a ramp on the tile on the hill) will not launch the cart. The cart would also not be launched with ''any'' valid ramp, even if it does not travel in an appropriate direction, such as North/South (which the cart will ignore, as it is not a curve, anyway, although it may produce acceleration that may cause diagonal movement.)

Carts that are traveling at derail velocity will also start "jumping" from the track if it hits an un-tracked tile, flying over and ignoring any tracks until it is ready to land. Carts that land upon tracked tiles re-rail themselves, and clever designers use this feature to jump over curved track sections in one direction or another. (Retracting bridges over untracked tiles can cause jumps or not cause jumps depending upon the status of the bridge.) Minecart speed must be carefully regulated to ensure reliability of jump length.

Hitting untracked tiles at around 70k velocity creates a vertical component to acceleration that allows for jumps of around 6 (horizontal) tiles that do not actually leave the z-level the cart is on, but which do apply z-direction velocity on the cart, as per falling.

Carts that approach a downward slope at a high enough velocity will also make a jump, (or rather, ignore the ramp and fly forwards) but will not do so if the Checkpoint Effect (below) is exploited through an impulse ramp before the actual downhill as the impulse ramp "tricks" the cart into thinking it has already started going downhill. The cart will also not fly off the ramp if there is a wall and ceiling preventing any motion but going down the ramp.

=== Skipping ===
If a minecart is moving fast enough, it can skip over [[water]] or [[magma]], making splashes of [[mist]] (or [[magma mist]]) as it attempts to move on them horizontally. This horizontal movement is independent of the minecart and its content's [[weight]].

Skipping causes significant friction on the cart, and even a cart going at max speed from ramps can only make about 50 tiles without requiring re-acceleration. (Carts that decelerate enough that they do not trigger the skipping effect will, of course, sink.)

=== Corner Ramp Derail ===

Corners on upward ramps can cause diagonal movement, forcing a derail even if the cart has a wall next to it, which will force a stop when it touches a wall that forces dwarves to manually reset the cart.

This is caused by the fact that a cart, after turning the bend in the track halfway through the length of the tile, will still "accelerate down", which is now perpendicular to the movement of the cart, causing acceleration to occur in two directions. (Down corner ramps do not have this problem, as when they pass the halfway point, all perpendicular motion is added to forward motion, and after that curve, all downward acceleration is in the forward direction.)

There are two fixes to this problem. One is to simply not put corners on up ramps. The other is to take advantage of the Checkpoint Effect, below, by making a ramp (possibly including an impulse ramp) one tile in front of the ramp to make it skip through most of the tile before sideways momentum can be built.

=== Checkpoint Effect ===
The checkpoint effect, [http://www.bay12forums.com/smf/index.php?topic=144328.0 explained in depth by Larix], is an odd and highly exploitable feature of ramps where minecarts "teleport" through the next tile of track, ignoring nearly all minecart physics (except that they stop at all walls or other obstacles and only respect curves with no backing wall and invalid ramps if they are below derail speed) and passing through that tile in just a single tick, and into the next tile at the halfway point.

This effect occurs when a cart leaves a downward ramp for any other direction of tile. (This includes ramps which accelerate in different directions, even a ramp which goes from accelerating East to accelerating North due to a bend in a chain of standard down ramps in a curve.) This allows, for example, two valid straight ramps directly next to one another with a cart dropped onto one or the other with no momentum to have the cart pick up acceleration going "down" the ramp as normal, but then flying up through the "up" ramp it travels into with no loss of momentum, as though it had come from an impulse ramp. If the two ramps had at least one space of distance between them, and then a cart were dropped in, the cart would instead "rock" back and forth between the two ramps.

This seems to be because ramps have a slightly longer length than regular tiles - 144,000, rather than 100,000 distance. When this "snaps back" after a ramp, it seems to project the cart suddenly further along the track, making it jump a tile ahead even when otherwise moving at relatively low speeds.

This [[bug]] is the cause of a ''wide array'' of unexpected behavior among people who do not take this bug into account. It causes derailments or failure to climb up seemingly valid impulse elevators. In general, it makes a system that behaves extremely counter-intuitively, and operates ''any time a cart encounters a valid ramp''. At the same time, when its effect is accounted for, it is highly exploitable: It causes "perpetual motion devices" using no power when two opposing ramps are placed next to one another, since the "uphill" effect of the opposing ramp is ignored, preventing deceleration.

Another useful thing to note about this exploit is that carts traveling at no less than 72,000 or so speed (enough to travel half a ramp tile in a single tick) can travel through every tile in just one tick at no change in velocity as long as the tiles alternate between impulse ramp or actual down ramp and any other tile type. The cart checkpoints through the non-down-ramp tiles, and can pass through the (impulse) down ramp tiles in a single tick, before they can actually start gaining momentum.

{{diagram|spaces=yes|\
▒▒▒▒▒▒▒▒▒▒ ▒▒▒▒▒▒▒▒▒▒
═▲═▲═▲═▲═▲═ ═╚═╚═╚═╚═╚═
▒ : Wall
═ : Normal track
▲/╚ : N/E Track/Ramp
}}

If the cart enters from the West at less than 72,000 speed, some of those ramps will cause Eastward acceleration.

This means that an impulse ramp not contiguous to other impulse ramps has a top speed of around 75k:

{{diagram|spaces=yes|\
▒▒▒▒▒ ▒▒▒▒▒
▒╔═╗▒ ▒╔═╗▒
▒╚▲╝▒ ▒╚╗╝▒
▒▒▒▒▒ ▒▒▒▒▒
}}
This setup makes a cart that travels clockwise at a speed that fluctuates around 75k velocity. If the cart has more than 72k velocity, it fails to accelerate in the ramp, as it leaves the ramp in a single turn due to checkpointing to the halfway point. After that, the curves sap 1k velocity, and every tick saps 10 velocity.

Two contiguous impulse ramps with a same-facing "downwards slope", however, do not suffer the checkpoint effect in the second tile, giving functionally triple the space to accelerate. This means it will add velocity (at the standard rate of 4.9k per tick) up to a maximum speed of 216k.
{{diagram|spaces=yes|\
▒▒▒▒▒▒ ▒▒▒▒▒▒
▒╔══╗▒ ▒╔══╗▒
▒╚▲▲╝▒ ▒╚╗╗╝▒
▒▒▒▒▒▒ ▒▒▒▒▒▒
}}
This example results in a cart moving three times as fast as the previous cart.

Three successive ramps results in the highest attainable speeds.

In practical terms, this means that only consecutive ramps should be used for high acceleration, but singleton ramps can be used to have speeds that are somewhat regulated.

=== Stacking ===
If a minecart lands on top of another minecart, they may form a stack, with the upper cart on the z-level above the lower. Subsequent carts do not form a stack, but rather quantum stockpile in the same space. This behaviour is useful for [[megaprojects]] and [[trap design]] with minecarts as the weaponry. Moderation should still be exercised: carts take longer to fall into a "stacking" tile already occupied by other carts and will spend that time "hanging" in the air above the stack. This can lead to following carts striking them, which can cause all kinds of malfunctions. The extra time is two game steps for every cart already in the stack, which doesn't hurt stacks of ten carts very much but makes stacks of 100+ rather impractical.

These minecarts on the upper level generally need to be struck with another minecart to move out, or have their support removed. The latter option is safest done by shooting it away with another minecart, manual removal of a stack-supporting cart typically causes the next cart from the stack to [[fun|fall on top]] of the hauler.

=== Perfectly Elastic Collisions ===
Minecart collisions are perfectly elastic, meaning that not only do minecarts not take damage, but that two carts that are rolling which have frontal collisions of near-similar speed, and where one cart is no more than twice the mass of the other cart, will result in a billiard-ball-like effect of the lighter cart bouncing off the heavier cart with a proportional speed increase dependent upon the relative momentum behind the heavier cart.

Using this trick with carts already at the 270,000 maximum speed from ramps can result in "supersonic" carts traveling at speeds in the millions (travelling a dozen tiles per tick), but where they are suddenly subject to 10,000 units of "terminal velocity" friction per tick. [http://www.bay12forums.com/smf/index.php?topic=137557.0 Thread with SCIENCE here].

While hypothetically capable of launching a minecart into orbit when used in conjunction with a ramp, no cargo can be contained in the launched cart, as the collisions will force ejections of the cargo. Your "unwilling volunteer" [[goblin]] space pioneers will simply become paste underneath the wheels of an extreme high-speed cart.

=== Numbers behind the scene ===

According to early research by '''expwnent'''{{cite forum|112831/3536975}}:

The minecart has a variable for speed. Speed is measured in tiles/100000 ticks, so a speed of one hundred thousand means one tile per tick. By going down a large number of ramps, a maximum speed of 270,000 can be reached, which presents the limit for most practical applications. Short bursts of (much) higher speeds are possible through carefully planned collisions of high-speed carts {{cite forum|137557/5145499}}.

Every tick the cart accumulates distance units, as well as slows down depending on current tile (speed is reduced by "friction" of the tile). The cart will move to the next tile the tick before accumulating 100000 distance units, (or several tiles in case of great speed), then the leftover distance units are added to the default 100000 distance u. of the next tile. Since most deceleration and acceleration is applied per step, with the notable exception of corners, a cart going at twice the speed of another one can cover about four times the distance in a straight line, but only twice the distance along a winding track with very many corners.

A push will teleport a cart to the beginning of the next tile (NOT the middle!) in one tick with 19990 speed (10 speed is lost due to track friction), while a roller will give a cart the roller's set speed, and it will start to accumulate regular track friction past the middle of the roller tile. Some track features will affect a minecart when it is past the middle of the previous tile: entering a ramp or a hole/drop will happen when the cart has left the middle of the previous tile, and the ramp will gain additional distance unit depending on the leftover units from the previous tile. When a cart leaves a ramp it will emerge after one tick in the middle of the next regular tile, so its entry coordinate is "50000-speed+friction". Rollers also affect the speed of minecart from the middle of the previous tile.

Friction of tiles:
{| class="wikitable"
|-
! Tile
! Friction
! Comment
|-
| Tracks
| 10
|-
| Ground/Floor
| 200
|-
| Unusable ramp
| 10
|-
| Upwards ramp
| 4910 (10+4900)
|-
| Downwards ramp
| -4890 (10-4900)
|-
| Roller
| ±100000 (but capped by the set speed)
|-
| Corner track
| 10
| Speed reduced by 1000 upon leaving the corner tile
|-
| Track stop (highest)
| 50000
|-
| Track stop (high)
| 10000
|-
| Track stop (medium)
| 500
|-
| Track stop (low)
| 50
|-
| Track stop (lowest)
| 10
|-
| Water 1-6
| Additional (WaterLevel - 1) * 100
| rowspan="2" | [[#Skipping|See Skipping]]
|-
| Magma 1-6
| Additional (WaterLevel - 1) * 500
|-
| Empty space
| 0
|}

Water of depth 7/7 provides a friction of about 10000 per step, as does maximum-depth magma. This higher friction may not apply to very slow-moving carts.

Impulse sources:
{| class="wikitable"
|-
! Feature
! Speed
|-
| Push
| 20000
|-
| Roller lowest
| 10000
|-
| Roller low
| 20000
|-
| Roller medium
| 30000
|-
| Roller high
| 40000
|-
| Roller Highest
| 50000
|-
|}

== Non-standard uses ==
Minecarts include some interesting characteristics that have motivated uses beyond hauling. They can be useful for creating fully-automated [[exploit|quantum stockpiles]] and [[garbage disposal]]s. Storing perishable goods (meat, meals, etc.) inside a minecart appears to guard against rot and vermin.
Minecarts can be [[Trap_design#Minecarts|used as weapons]], or as (hopefully non-fatal) triggers to restart stalled [[healthcare]]. They can also be used to time/control game events, either using a basic [[repeater]] or much more advanced [[minecart logic]].
Minecarts trigger [[pressure plate]]s, which means a trap can be designed to trigger when a thief attempts to steal a minecart.
A pressure plate can be used as automatic and more precise custom "launch when full enough" system - as long as weight of your minecarts stays the same. You cannot build a hatch or roller on the same tile, so launch by bumping with another cart. {{cite forum|15096/4580050}}
Dwarves riding minecarts can attack enemies within reach (which goes back to dev log). This applies to shooting, and they actually can hit targets while riding by.{{cite forum|109460/5266119}} Whether a minecart protects the rider and how it interacts with dodging is not known yet. Minecart riders can also [[Swimming#Minecart_training|train swimming]] and [[Megaprojects#Surveillance_Track|detect ambushers]].

== Adventure mode ==
In addition to being used for hauling, minecarts can also be ridden in [[adventure mode]]. (Adapted from forum thread {{cite forum|122903/4258212}})

# If the minecart is in your inventory, drop it. If it is already on the ground, proceed to step 2.
# Press {{k|u}} when you are 1 tile away from the minecart (or standing on the same tile as the minecart).
# You will be presented with the following options:
[[File:minecart adventure mode menu.png|left]]
{{clear}}
* If you {{DFtext|Push}} the minecart, it will move a few tiles in the direction you chose. Physics comes into play here, so it will gain/lose speed depending on the usual factors.
* If you {{DFtext|Ride}} the minecart, you will hop into the minecart, even if you were a tile away, and it will move in the chosen direction with you in it. It will gain/lose speed depending on the usual factors. Whilst the minecart is in motion, you should press {{k|.}} to skip your turn; if you attempt to move whilst the minecart is still in motion, the laws of physics come into play, and you will take [[wound|damage]]. Alternatively, you can push the minecart whilst it's still in motion (although it's unclear how one can bend [[physics]] so as to push a moving minecart whilst inside the minecart). If you push it in the same direction you are already travelling in, you will greatly increase the minecart's velocity. You can also push it in different directions, and this will cause it to gradually change direction-the amount of pushes this requires depends on the minecart's velocity. Once the minecart has stopped moving, you may move out of it safely, or you may want to give it another push. Note that if you push a minecart right after having ridden it (still on the same tile as the minecart), it will act as though you chose to ''ride'' it.

If you want to test this out without creating an adventurer, the [[object testing arena]] allows you to spawn minecarts ({{k|k}}-{{k|c}}-{{k|n}})

== Forging and Melting ==
* Metal minecarts cost '''two''' [[metal]] bars to forge, or '''six''' [[adamantine]] wafers.
* When a non-adamantine metal minecart is melted down, it will return '''1.8''' metal bars, for an '''efficiency of 90%'''.
* When an adamantine minecart is melted down, it will produce '''1.8''' wafers, for an '''efficiency of 30%'''.

== See also ==
* [http://www.bay12forums.com/smf/index.php?topic=109460.0 The "How Does Minecart" Thread] by '''Girlinhat''' et al.
* [http://www.bay12forums.com/smf/index.php?topic=112831.0 SCIENCE: Quantifying minecart physics] by '''Snaake''' et al.
* [http://www.bay12forums.com/smf/index.php?topic=129676.0 How to build a Multi-cart Ore to Magma Minecart Project without needing power] by '''WanderingKid'''.
* [http://www.bay12forums.com/smf/index.php?topic=144328.0 My very own Minecart Education Thread. Ten Lessons, now complete.] by '''Larix'''.

== Bugs ==
*A dwarf will drop her [[child|baby]], if she has one, when boarding a minecart set to be ridden.
*Dwarves have no concept of traffic safety and will walk into busy minecart lines to retrieve objects, often with deadly consequences. This is especially problematic in [[Swimming#Minecart_training|clever applications]] depending on dwarves riding the carts very frequently, because they have a bad habit of dumping their worn clothes on the tracks after a minecart ride. Adding an automatically-operated [[hatch cover]] at the end of such a ride can help prevent [[unfortunate accident]]s.
*Dwarves cannot guide a minecart through an unlocked door unless another dwarf opens the door.{{bug|6056}}
*It is possible for a creature and minecart moving towards each other to pass without collision if they exchange tiles in the same tick.
*After a minecart ride, a dwarf will sometimes haul the minecart to a storage stockpile, leaving another dwarf to haul the vehicle back to the route.
*Minecarts falling onto a floor injure creatures in the tile below the floor.{{bug|6068}}
*A minecart's initial velocity is not affected by weight, when pushed or launched from rollers.{{bug|6296}}
*Removing a stop that has a vehicle waiting on it may cause the game to crash.{{bug|5980}}

{{Category|Fortress mode}}
{{Category|Interface}}

[[ru:Minecart]]

Minecart

2015-06-21T00:09:35Z

NW Kohaku: /* Track Direction Irrelevance */ grammar failure

{{Quality|Masterwork|08:15, 19 May 2015 (UTC)}}
{{av}}
A '''minecart''' is a [[tool]] intended for [[hauling]], introduced in version 0.34.08. It can be made of [[wood]] at a [[carpenter's workshop]] or [[metal]] at a [[metalsmith's forge]] (using the [[Metal crafter|metalcrafting]] labor.) Minecarts store up to five times as many items as [[wheelbarrow]]s and are quite a bit faster than dwarves hauling objects by hand, but have the disadvantages of requiring a dedicated track network, a complex route planning phase, and the possibility of dwarves [[Fun|blundering into the path of carts filled with lead ore]]. Tracks may be carved into stone, or [[Construction|constructed]]; the latter allows above-ground routes, but these are more difficult to set up due to their additional [[building material|material requirements]].

Just like wheelbarrows, minecarts are considered [[item]]s and are stored in a [[furniture]] [[stockpile]]. Despite their five-times-greater capacity, they are only 33% larger than wheelbarrows and are identical in base [[item value|value]] when made from the same [[material]] (the value may differ due to the [[item quality]]). [[thief|Thieves]] or even mischievous animals can steal minecarts, even when they are moving on a track{{cite forum|109460/3289070}}. However, minecarts moving fast enough or being ridden cannot be stolen.

Although most of the utility of minecarts is in [[fortress mode]], an [[adventure mode|adventurer]] can also ride in a minecart. Adventurers can also pick up and relocate minecarts.

The invention of minecarts revolutionized the [[minecart logic|Science of Dwarfputing]] by enabling smaller, faster logic systems to be built.

== Basic Minecart Usage ==
Minecarts can be used to swiftly transport dwarves, [[flow|fluids]], and/or large amounts of items, but before you have a functional minecart there are several preconditions that need to be met. First of all you need an actual minecart, constructed either in a [[carpenter's workshop]] or [[metalsmith's forge]]. For the minecart to be able to move you also need to carve (with {{k|d}} {{k|T}}) or construct (with {{k|b}} {{k|C}} {{k|T}}) a track, which could be as simple as a straight line. Finally you need to construct stops on your track (with {{k|b}} {{k|C}} {{k|S}}) where the minecart will start and stop.

After you have created the stops and assigned a cart to the track, you must create logic routes connecting several stops and designate starting conditions for each stop. This is done with the {{k|h}}auling key. The most basic conditions are how the cart's movement is initiated and in which direction the cart should start moving. Carts can be either be Pushed (a dwarf stands at a stop and gives the cart a single push) or Guided (a dwarf continually pushes the cart forward, guiding it along the track). The [[hauling]] [[labor]] required for pushing and guiding carts is called "Push/Haul Vehicles" and is turned on by default.

To control which items to transport you can add conditions specifying: (1) which kind of items to be loaded, and unloaded, (2) stockpile links to define which stockpile(s) the items should be un/loaded to and from.

===Capacity and weights ===
Minecarts have five times the [[Weight|capacity]] of [[wheelbarrow]]s.

'''Examples of the capacity of one cart'''
{| class="wikitable"
|-
! Item
! Amount
|-
| [[stone]]
| 5
|-
| [[wood|log]]
| 10
|-
| [[block]]/[[bar]]
| 83
|-
| [[Kitchen|prepared meals]]
| 500
|-
| [[Trap_component#Spiked_ball|spiked balls]]
| 500
|-
| [[Weapon#Native_weapons|mace]]
| 625
|-
| [[Weapon#Native_weapons|spears]]
| 1250
|-
| [[cloth]]
| 2500
|}

The weight of the loaded minecart does not affect the initial velocity received from pushing or launching from a roller. However, the load of a minecart ''does'' affect whether a [[pressure plate]] triggers or not, based on the pressure plate's setting.

'''Weights of different carts'''

{| class="wikitable"
|-
! Type of cart
! Empty cart
! Fully loaded (items)
|-
| oaken minecart
| 28Γ
| 378Γ (10 oak logs)
|-
| platinum minecart
| 856Γ
| 10482Γ (83 gold bars)
|}

The weight of a minecart is one twenty-fifth (1/25) the [[density]] of its material in Urists. Because pressure plates can be set to trigger at intervals of 50 Urists, minecarts with weights just under a multiple of 50 are ideal for switching based on whether they're full or empty. The best minecart materials for full/empty switching are as follows:

{| class="wikitable sortable"
|-
! Material !! Minecart weight !! Content weight required to trigger !! Banana roasts required to trigger (for scale)
|-
| [[Bismuth]] (moods only) || 391 || 9 || 15
|-
| [[Brass]] || 342 || 8 || 14
|-
| [[Electrum]] || 596 || 4 || 7
|-
| [[Fine pewter]] || 291 || 9 || 15
|-
| [[Glumprong]] || 48 || 2 || 4
|-
| [[Lay pewter]] || 291 || 9 || 15
|-
| [[Nickel silver]] || 346 || 4 || 7
|-
| [[Tin]] || 291 || 9 || 15
|-
| [[Trifle pewter]] || 291 || 9 || 15
|}

=== Creating tracks ===
Minecart tracks are made up of contiguous track, tracked ramp, or bridge tiles. Track tiles and tracked ramp tiles have a direction or series of directions associated with them. These directions dictate which directions a minecart on a given tile may move from that tile. For example, a Track NE (northeast) tile allows a minecart on it to move either north or east from its present position. Therefore, if you want your minecart to move east along a straight piece of track, then return west using that same track, you would need to use EW tracks so that the cart could travel east initially, then return west over the same track. Excluding designs in which the cart will "jump" tracks via a drop or other ramp, tracks must be valid end to end to work for most looped or straight-track applications. A single east only track tile in your line of east-west tracks will cause any route using the track to fail the moment it tries to go the wrong way over that tile. Minecart tracks can be built in two ways: Engraved/carved or constructed. A given minecart track need not use engraved or constructed elements exclusively, as the two methods can be used interchangeably depending on the needs of a given section of track. The way the tracks are built is slightly different between the two, as explained below.

====Simple tracks====

'''Carved'''

A single-tile wide strip of natural stone can be designated to be [[Engraver|carved]] (with {{K|d}} {{k|T}}), which will create a straight two-way track. The creation of corners, crossings, and T-junctions is as simple as designating another strip of track that overlaps an existent or newly designated track. Engraved tracks are removed by [[smoothing]] the rock they're on, which results in a smooth floor (that can be re-engraved if necessary), or by building a [[floor]] on top and subsequently removing it. Dwarves can carve corner tracks in one pass by designating the track carving twice and canceling unwanted carvings (with {{K|d}} {{K|x}}). Tracks can be engraved in any natural floor tile, rough, smooth and even over engravings, providing an easy method to remove low-quality or undesired floor engravings. Once a track has been engraved, it's important to check the track directions for each tile in the route carefully to make sure no mistakes were made by yourself or the game's track engraving logic.

'''Constructed'''

Tracks can also be built as regular [[construction]]s (through {{K|b}} {{K|C}} {{K|T}}). This method is resource-expensive, since each track tile requires one stone, [[bar]], or [[block]] for construction, and time-consuming, since you can't designate strips longer than 10 tiles at a time. Corners, crossings, T-junctions, and ramps also have to be designated individually. However, it is usually the only way to build tracks above ground or on soil (barring the [[Obsidian farming|creation of obsidian]]). Constructed tracks are designated for removal like any regular construction; be aware that removing track ramps built on top of natural ones will also remove the original ramp, leaving a flat floor.

====Ramps====

'''Carved'''

The carving of natural ramps is a little more confusing: to carve a two-way track on a ramp (natural only, does not work on constructed ramps), you must designate the track '''starting on the ramp and one square beyond''' in the direction you want the track to go. For the side of the ramp square you want to head upward, there '''must''' be either a natural or constructed wall in the square next to it, otherwise the game assumes you are trying to carve it on the same level -- this can result in the track being carved underneath a door or other object. If you have accidentally done this, you can correct it by smoothing the ramp and constructing a single square of wall next to it, then re-carving the ramp correctly. (However, the wall must stay there permanently; removing it will disconnect the track.)

'''Constructed'''

When constructing track ramps, the stated direction should be the same as the connected tracks. For example, a track going up from West to East would require, starting from the West, a Track (EW), a Track/Ramp (EW) and a Wall behind the ramp, underneath the section of track above it. Incorrectly placed ramps result in minecarts ignoring the ramp and crashing into the supporting wall. They will not, however, display as unusable as when the supporting wall is missing.

'''Examples of ramps'''

A simple ramp would look like this:
{{diagram|spaces=yes|\
z +0 z +1
░░░░ ░░░░
═▲o ░▼═
░░░░ ░░░░
o : wall
}}

Carving track corners into ramps is rather unintuitive and complicated. Since engraving tracks always requires two tiles to connect in a straight line as input, you have to give two separate designations for a single job: a track bit from the ramp tile to the "below" direction and another one to the wall of the "upward" direction. If you wanted to change direction on a ramp from east to north:
{{diagram|spaces=yes|\
z +0 z +1
░░░░░ ░░░░░
░░░░░ ══╗░░
=▲░░ ░░▼░░
░░░░░ ░░░░░
}}
you would need to connect the ramp on z +0 both to the west and to the north by issuing two "carve track" commands, one selecting the ramp and the track tile to the west, and another connecting the ramp tile with the wall to the north. An engraver would then carve a NW track corner into the ramp, allowing carts to pass the corner correctly both going up and down. Such track corners are perfectly serviceable for guided carts, but moving down a route of several of them by pushed or ridden cart is problematic - ramps on corners behave very counter-intuitively, resulting in loss of speed when going down and diagonal movement when going up.

Moving to and from ramps (or between ramps "pointing" in different directions0 causes some non-trivial adjustments to speed and even moving along the tiles at a fixed speed ''unrelated to the entry/exit velocity values'', because transitions to/from ramps are processed differently and are not to be "skipped". This affects compact track/ramp combinations (such as e.g. a simple 2x2 ramp spiral) most, and combined with bouncing often makes them work not in the way one could expect. {{cite forum|144328/5705102}}

{{anchor|Tracks}}

=== Hauling route ===
A hauling route is a list of directions describing how and under what conditions a minecart will move. The proper setting up of routes is essential for a working rail system. Routes, stops, departure conditions and stockpile links are managed from the {{k|h}}auling menu.

==== Route ====
A route defines the path a minecart will take along a track, as well as under what conditions it will move or stop moving. A route is made up of stops. Stops are precisely what they sound like, a position on the track at which you want a minecart to stop. A minecart track might use as little as a single stop for a looped track, which will serve as both a starting and stopping point for the cart, or it could contain many stops, perhaps to load supplies or wait for a bridge to be manually lowered, before reaching its destination or returning to its starting point. It is important to note that you only need to place stops on a route where you actually want the cart to stop and wait for some action to occur. They are not needed to help navigate the cart along the track beyond telling it where on the track to stop.

New routes are created with the {{k|h}}auling key. Existing ones can be removed (without confirmation) with the {{k|x}} key, and also {{k|n}}icknamed. Before operating, the route must have a {{k|v}}ehicle assigned to it (this can be done with either the route or a stop selected). Assigning a full minecart to a route may result in a slow hauling job if the contents are heavy.

==== Stops ====
Stops are the individual waypoints that make up a hauling route. A given stop consists of the location of a tile, as well as conditions describing when, where, and how a cart should be moved after being stopped at that tile. Stops can be created from within the {{k|h}}auling menu, by placing the cursor over a tile and hitting {{k|s}} while highlighting the route (or a stop within) you've already designated. A minecart will begin its route at the first stop created, and continue through each subsequent stop, being guided, pushed, or ridden from each stop to the next depending on the conditions specified. In many basic minecart applications, the cart will end up at the same stop it began at, though this is not always the case. It is important to note that hauling stop order is enforced, even if there is no track. A dwarf will drag the cart overland back to a skipped stop in the route's list if your tracks bypass it somehow.

Once a stop has been placed, it is given a default set of conditions under which to move the minecart if it is stopped there. Each new stop gets the same default conditions regardless of the track it is placed upon (e.g. guide the cart to the north). For this reason new stops might get marked by yellow exclamation marks ({{DFtext|!|#ff0}}) due to invalid directions. One important thing to note is that as you place additional stops, the display will show paths between the stops you have defined. However, this is '''not''' necessarily the actual route the minecart will take once the route is in operation. For example, if a route were defined with two stops at opposite ends of a track with many twists and turns, a line will be drawn directly between those stops to show the order in which they will be visited. These route lines may crisscross all over the tracks, but so long as the track is valid end to end, the cart will follow the track from one stop to the next, even across twists, turns, and z-level changes. Stops, which are the steps that make up a route, should not be confused with Track Stops, described below.

===== Stockpile links =====
By placing the cursor on top of a stockpile and using {{k|s}}, you can create stockpile links while defining a hauling stop. Links can also be redefined by selecting them, placing the cursor over a different stockpile, and pressing {{k|p}}. The cart will then be filled by items present in its various linked stockpiles in preference to other items. Note that bins should be used with caution in stockpiles that are linked to minecarts. Bins cause problems when used with the "Desired Items" list in a stop's conditions. For example, if a minecart is set to accept only granite blocks, and to depart north when it is 100% full of granite blocks, it will not depart if any of those granite blocks are in bins, even if bins are also included in the desired items list. Two solutions to this problem exist as of v0.40.24. First, bins can be disallowed in stockpiles that are linked to stops. Alternatively, bins '''can''' be used in conjunction with minecarts provided that the minecart's departure conditions use only "any items" instead of "desired items." This option can be toggled in the advanced conditions menu for a stop, accessible via the {{key|C|}} key. The cart's contents can still be controlled by specifying what items are allowed in the linked stockpile.

===== Departure condition =====
Departure conditions involve setting conditions in which the minecart will leave on the route. Each condition includes:
# A departure mode (Guide, Ride or Push).
# An initial departure direction (NSEW). Note that this defines the initial direction of movement only. Even if a track includes many turns, as long as the initial movement direction is valid the cart will follow the minecart track thereafter.
# A timer, before which the departure condition cannot be met.
# Conditions on the amount of items in the cart.
Departure conditions are created with the {{k|n}} key. A new departure condition will read: "guide north immediately when empty of desired items". This condition can be changed between basic presets with {{k|c}}. "Advanced" mode ({{k|C}}) allows for more precise control over departure conditions: fine tuning the percentage from 0 to 100 in 25% steps ({{k|f}} and {{k|F}}), switching it being either the maximum or the minimum amount of items for the condition to be met ({{k|m}}), and whether the cart accepts all or only a specific set of items ({{k|l}}). Common to both screens are the departure mode ({{k|p}}, Push, Ride or Guide), {{k|d}}irection, and timer ({{k|t}} and {{k|T}}) options.

To have a cart only carry a specific set of items, the stop can be set to only carry "desired" items, opening the selection screen with the {{k|Enter}} key while having said stop condition selected, and toggling as desired, or it can simply be linked to a stockpile and set to depart once it is full of items from its linked stockpiles, regardless of type.

=== Track Stops ===
A Track Stop, not to be confused with a route stop, is an optional, single-tile construction which serves two purposes. First, it can be used to cancel a cart's momentum in order to slow or stop it as it passes over the Track Stop. This might be necessary if a cart were pushed down a series of ramps to its destination. Second, a Track Stop can cause a cart to automatically dump its contents as it passes over the Track Stop. Track Stops are constructed via {{k|b}} {{k|C}} {{k|S}}, and must be constructed atop an existing piece of track. If a Track Stop has been set to automatically dump a cart's contents, the cart will dump its contents in the direction indicated when it passes over the Track Stop. Depending on the friction settings chosen for the Track Stop, the cart might then stop after dumping, or it might continue on its route to another destination.

Track Stops are not mandatory; in fact, their main use is in automated rail systems. However, even in basic rail systems it can be useful to set a Track Stop to dump items: this saves time that dwarves would otherwise spend in removing items from the cart, time that is better spent driving the cart back to where it's needed. Dumping will occur even with a guided cart. '''Take care not to set Track Stops at a loading site to dump their contents''', or dwarves will never be able to fill the cart. It will dump any contents the moment they are loaded.

Counter-intuitive to their construction method, Track Stops are considered [[building]]s and must be removed by {{k|q}} {{k|x}}.
* See [[#More_on_Track_stop |More on Track Stops]]

=== Step-by-step tutorial ===

Let's construct a simple minecart route. This route will move stone blocks from an input stockpile to an output stockpile. We'll begin by creating the stockpiles:

[[File:minecart-example-1.png|Stockpiles designated.]]

The input stockpile is on the left; the output stockpile is on the right. We'll be moving blocks from left to right. Disable bins in both stockpiles, and set the input stockpile to accept only from links. Then make the stockpile take from the mason's workshop where the blocks are being produced.

Next, carve the track:

[[File:minecart-example-2.png|Track carving designation.]]

Note that the ends of the designation are uniquely shaped; this is automatic, and not anything you need to control. Now, wait for your engravers to come along and carve the track into the stone. (Your haulers will probably also fill up the input stockpile while you wait.)

In addition, while we're waiting for that to happen, we'll build an iron minecart in the forge.

[[File:minecart-example-3.png|Track carved.]]

When the track has been carved, it will look like the above (the track will be solid instead of flashing). Now, order a track stop to be constructed next to the output stockpile:

{|
| [[File:minecart-example-4.png|Track stop designation.]]
| [[File:minecart-example-5.png|Select dumping direction.]]
|}

You must press {{k|d}} three times to select the dumping direction ''before'' placing the track stop. We want our blocks to be dumped into the output stockpile east of the track stop. Then wait for a mechanic to come along and build the track stop.

[[File:minecart-example-6.png|Track stop constructed.]]

Now we'll define the actual ''route''. This is done in the {{k|h}}auling menu. Press {{k|r}} to begin defining a route. Next, move the cursor to the input end of the track, and then press {{k|s}} to define the first stop:

{|
| [[File:minecart-example-7.png|Stop 1 designation.]]
| [[File:minecart-example-8.png|Route definition, in progress.]]
|}

Move the cursor again, to the output end of the track, and press {{k|s}} again to define the second stop:

{|
| [[File:minecart-example-9.png|Stop 2 designation.]]
| [[File:minecart-example-10.png|Route definition, two stops.]]
|-
|
| [[File:minecart-example-11.png|Stops are not defined yet.]]
|}

There are several user interface features to note at this point. The stops have been positioned, but they haven't been ''defined'' yet, so there is a warning {{DFtext|!|#ff0}} symbol by each of them. In the lower right corner, we see what the {{DFtext|!|#ff0}} means. Also, note that the second stop is labeled in white, while the other two lines are grey. The white text is a selection indicator, and can be moved up and down by pressing {{k|+}}/{{k|-}}.

Next we need to define what our stops do. We want the minecart to be filled with blocks at the first stop, then travel to the second stop where it will dump its cargo, and then return. Press {{k|-}} to move the selection up to stop 1, and {{k|Enter}} to open it up. By default, the stop has three conditions:

[[File:minecart-example-12.png|Default stop definition.]]

We don't want any of these, so press {{k|x}} three times to delete them. This leaves us with a blank stop. Now we can add the conditions we actually want. Press {{k|n}} to begin adding the first condition, then {{k|d}} twice to change the direction from north to east. Then press {{k|c}} to change the condition from empty to full. This will instruct the minecart to be guided east when full of desired items.

To set the desired items, we create a stockpile link. Press {{k|s}}, then move the cursor to the input stockpile, then press {{k|p}} to select that stockpile. Now press {{k|Enter}}; this opens up a selection screen that resembles the stockpile customization screen. Move down to Blocks, {{k|e}}nable them, then (if you wish) restrict it to stone blocks.

When you've done all that, stop 1 should look like this:

[[File:minecart-example-13.png|Stop 1, defined.]]

Stop 2 is much simpler. All we need to do is have the minecart return to the input stop. So, make a condition and change the direction:

[[File:minecart-example-14.png|Stop 2, defined.]]

Finally, we just have to assign our minecart. Go back to the route definition screen, and press {{k|v}}. Select the minecart, and press {{k|Enter}}.

Now we've got everything set up:

[[File:minecart-example-15.png|Route, fully defined.]]

The V is red because the minecart hasn't been moved onto the track yet. Some dwarf will have to haul it from the forge to the first stop, by hand; this will take a while, especially if the forge is far away.

Once the minecart is in place, dwarves should fill it with blocks from the input stockpile, which will in turn be filled with blocks from the workshop where your mason has been toiling dutifully. When the minecart is full, the blocks will be dumped into the 1x1 stockpile on the right. Automatic quantum dumping!

=== Troubleshooting ===

Because of the complexity of the system, all but the most careful and experienced minecart users will encounter issues. Most route issues can be diagnosed and fixed from the {{k|h}}auling menu.

'''Symptom:''' {{DFtext|! Set dir/connect track|6:1}} message appears to the right of one or more stops

'''Possible Causes:'''
* The departure direction of the stop might be invalid. Edit the stop using {{k|Enter}} and press{{k|d}} until it is pointing in a valid direction.
* The track stop might not be built on top of a track. The track stop must be deconstructed to remedy this issue.
* Your track might not be built correctly. Make sure all connected tracks between destinations are not one-way tracks.
** This can be especially confusing with ramps. To carve a two-way track on a (natural) ramp, you must designate the ramp and one square beyond in the direction you want the track to go.
** Ramps '''must''' have a solid block on the side opposite to the track, or they will neither work nor be marked as "unusable". The solid block can be natural or constructed.
* The desired/kept items might not be configured correctly.

'''Symptom:''' The status '''0% V''' always appears to the right of one stop.

'''Possible Causes:'''
* The stop may not be set to take from a stockpile. Edit the Stop using {{k|Enter}} and make sure you see a message like "Take from Stockpile #1".
* The take conditions must correspond with the contents of the stockpile.
* The track stop may be set to dump. A track stop set to dump cannot be filled. You must either set the stop to a time-based departure or deconstruct the track stop and rebuild it without dumping. (Alternatively, with [[DFHack]] you can modify "Dump on arrival" to "No" using the {{key|q}} menu without rebuilding the stop.)
* Make sure the minecart itself has not been designated to be dumped (such as when using mass-dump).

'''Symptom:''' Dwarves fill the minecart properly, but will not move it thereafter.

'''Possible Causes:'''
* The minecart may contain items which are not included in its current stop's desired items. Check inside the minecart using the {{key|k}} and {{key|z}} keys and ensure that all items in the cart are desired items.
* The minecart may contain desired items in bins. Minecarts seem to have problems realizing that they are in fact full of desired items if some of those items are in bins, even if bins are also among the desired items for that stop. '''This cannot be solved by adding the appropriate bins to the stop's desired items.''' Either disallow bins in stockpiles you intend to load minecarts from, or set the departure conditions to rely only on percentage of total load rather than percentage of desired items using the advanced conditions menu ({{key|C}} key).

'''Symptom:''' Dwarves repeatedly attempt to load the minecart, but no items are ever loaded into it.

'''Possible Causes:'''
* This can be caused by using a Track Stop with autodumping enabled at a loading site. Every time a dwarf places an item into a cart resting on such a track stop, the item will be immediately dumped, causing unlimited, useless cart loading jobs. Autodumping Track Stops should never be used at a loading site.

'''Symptom:''' A dwarf picks up the minecart and carries it to its destination.
* See [[#Quirks|Quirks]]

=== Danger ===
Minecarts are not without <strike>danger</strike> [[fun]]. Although designating a track automatically sets the [[traffic]] designation to low, dwarves ''may'' still walk on them, and [[creature]]s ignore traffic designations altogether. If an unlucky dwarf or creature fails to [[dodger|dodge]] a minecart, they can be injured. Most of this danger can be avoided by setting the minecart {{k|h}}auling commands to guide instead of push or ride (dwarves guiding minecarts will ignore traffic restrictions), as well as by [[pasture|pasturing]] domestic animals and preventing the access of other creatures to the tracks. Note that removing the track doesn't reset that tile back to normal traffic priority, so you may wish to manually clean up traffic designation afterward. Also note that bridges that are used as tracks don't have their traffic priority changed automatically (since they're just normal bridges), which could cause dwarves to pathfind normally through dangerous minecart entrances in your fort's walls if you're not careful.

The only <s>fool</s>''dwarf''-proof method is to make the tracks inaccessible. There are several ways to create a track which works for minecarts but doesn't allow creature-traversal; the simplest is perhaps building a [[statue]] on the tracks. Other options include adding single-tile holes (minecarts moving at reasonable speed will jump the gap), vertical drops, minecart-triggered doors, small pools of liquid (4/7 water or 2/7 magma), and hostile creatures overlooking the tracks. For safety, both ends of the track should be isolated, making the dangerous center sections completely inaccessible (though maintenance access can be provided by a locked door).

Danger does not always involve living victims: careless route designation can also result in minecarts careening off tracks or colliding with each other. If this occurs, the [[item]]s may be scattered; this can cause even more hauling jobs than the minecart aimed to eliminate. Even <s>better</s> worse, scattered items, especially [[weapon]]s, can injure passing [[dwarf|dwarves]] or other [[creature]]s; in the words of Toady One the Great, "Accidental grapeshotting of the dining room should be possible now."

Of course, the danger of using minecarts means they can also be [[Trap_design#Minecarts|used as weapons]] by imaginative players.

== Advanced usage and automation ==
Minecart-specific effects are implemented via track stops, rollers and [[pressure plate]]s with "track" condition set. Since all three are considered [[building]]s, they can't be built on the same square (however convenient track stop + pressure plate would be) nor a simple ramp, and are removed by {{k|q}} {{k|x}}.

=== More on Track stop ===
Track stops are constructions that allow further automation of minecart systems via adjustable features such as braking by friction and automatic dumping of contents. They can be built from logs, bars and blocks through {{K|b}} {{K|C}} {{K|S}}; friction amount, dumping toggle and dumping direction must be set '''before''' construction, and these settings can be neither changed nor seen thereafter; however, track stops can be linked to [[pressure plate]]s or [[lever]]s to toggle friction and dumping On or Off (trigger state is inverted: switch On = track stop Off).

If a [[stockpile]] is placed on the tile that a track stop is set to dump to, it can act as a [[Exploit#Quantum_stockpiles|quantum stockpile]] and any items dumped from a minecart that match the storage settings of the stockpile will remain there and accumulate. Normally trackstops are built on top of existing track to operate on moving minecarts, but they can also be used without tracks to create [[Exploit#The_Minecart_Stop|automatic quantum stockpiles]] (see also [[#Step-by-step_tutorial|step-by-step tutorial]]). It is not always desirable to collect ALL of certain items into one quantum stockpile, such as when distributing a material to multiple separate industries. You can link your quantum stockpile to various other stockpiles, ensuring that your dwarves will keep them supplied as necessary. Because quantum stockpiles never fill up like regular stockpiles, it may be a good idea to add a switch to turn them off.

Items dumped from a minecart at a track stop (or dumped by any other means) into open space fall through z-levels until they land on a solid surface. Items falling onto a designated [[stockpile]] will automatically be considered part of that stockpile, even if the stockpile is set to disallow those items (they will, however, be automatically moved to a more appropriate stockpile, if available). Items falling on top of a minecart will '''not''' fall "inside" the minecart. Use with caution; dwarves have fragile skulls.{{bug|5945}}

=== Automated propulsion ===
==== Roller ====
{{Main|Roller}}

A '''roller''' is a [[power]]ed [[machine component]] for the automated propulsion of minecarts. They are built over the top of existing tracks with {{K|b|M|r}}, requiring a [[mechanic]], ''(length/4)+1'' [[mechanism]]s and a [[rope]]. Rollers may also be placed directly on ramps to help pull carts up Z levels. Rollers are very useful to maintain a cart's momentum along long routes, to get them to climb Z-levels without dwarfpower involved, and to get them to reach speeds unattainable by guiding dwarves. These devices are variable-length (1-10), variable-direction and variable-speed ([[Minecart#Numbers_behind_the_scene|see below]]), all traits that can be set at construction time; a roller uses two units of power per tile it is long.

Single-tile rollers transfer power in all four cardinal directions, while other rollers generally only transfer power perpendicular to their activity direction. Longer rollers can also transfer power along their activity direction if built in the correct order, although this can be hard to accomplish and is easily broken. Rollers cannot be powered from above.

Rollers have great acceleration and capped speed. Carts going faster than the roller are unaffected. If a cart moves across an active roller in the direction the roller works and moves slower than the roller's specified speed, the cart will be set to the roller's speed. A cart going against a roller's movement direction will be sent back the way it came (once again at the roller's speed), unless it was moving extremely fast: speed increment of 100000 allows to reverse carts from the full "highest" (50000) speed roller to full "highest" speed back, but ramps can accelerate a cart beyond this. {{cite forum|144328/5702453}}
A cart crossing over a roller perpendicular to its current movement direction will gain the roller's amount of speed in the perpendicular direction without directly changing its forward motion. Without an adjacent wall to constrict its movement, this will typically send a cart off the rails on a diagonal path, completely unable to follow any tracks until it collides with a wall or is otherwise brought to rest. However, if the roller is placed over a track turn and pushes ''from'' the direction of that turn's track, the turn affects carts ''after'' the roller, so they will be forced into the turn rather than derailed in a diagonal direction. {{cite forum|144328/5702453}}

{{diagram|spaces=yes|\
tracks: full:
║ ║
═╗═ ═╢═
║ ║

╢ : roller pushing from W to E
}}
If the roller is powered, carts from ''all'' directions (unless too fast) exit S, because speed imparted by the roller forces carts toward E and ''then'' into the turn.
If not powered, carts from W and N exit S, carts from E and S exit W. Carts above derail speed will ignore the turn, of course.

{{diagram|spaces=yes|\
║ ║
═╗═ ═╟═
║ ║

╟ : Roller pushing from E to W
}}
Carts from the E or W: exit W.
Carts from N: derailed diagonally, exit SW.
Carts from S: derailed diagonally, exit NW.

Rollers affects carts on a track - if placed on a floor or ramp without any tracks, they are ignored. Depowered rollers are also ignored, friction is determined by the tiles underneath.

Because of their one-way nature, rollers are unsuitable for most two-way minecart tracks (unless you set gears toggling roller A->B off while toggling A<-B rollers on). However, a minecart set to be ''guided'' is not affected by rollers at all{{cite forum|109460/3286235}} — this allows a one-way track to be used in both directions. In addition, unpowered rollers do not affect minecarts.

Care must be taken in [[glacier]]s and other extremely cold [[biome]]s, since rollers (and the machinery used to power them) will not operate when constructed on natural [[ice]] floors.

==== Impulse ramps ====
Carts can be given momentum without rollers or changing z-level through a phenomenon called "impulse ramps". A track ramp which is connected both to a wall and to a floor will ''always'' accelerate a cart towards the connected floor tile, no matter where the cart enters the tile from. This means carts can be accelerated as though dropping z-levels, even if the cart doesn't actually change z-level at all. If a track ramp faces three directions such as ╩, then two of those directions need to be facing walls for the cart to be accelerated towards the remaining direction.

Example of straight impulse acceleration:

{{diagram|spaces=yes|\
▒▒▒▒▒▒▒▒▒▒ ▒▒▒▒▒▒▒▒▒▒
═▲▲▲▲▲▲▲▲▲▲═ ═╚╚╚╚╚╚╚╚╚╚═
▒ : Wall
═ : Normal track
▲/╚ : N/E Track/Ramp
}}

If a cart enters from the left, it will speed up on every track/ramp and exit to the right going very very fast - more than one tile every step. If it enters from the right then it will bounce back impulsed by the ramp if it's going slow enough.

As another oddity, carts coming from ramps will in some cases "teleport" through most of the next tile. This is called the "checkpoint effect", and is explained in detail in the Physics section, below. This negates the deceleration of the next tile if it is a ramp "angled" in a different direction. You can just make an upward spiral alternating impulse ramps and regular upward ramps. It takes no power, is quick and cheap to build, requiring only channeling and track carving, and the cart goes up fast, but not so fast that it launches its contents.

Example of an impulse elevator:

{{diagram|spaces=yes|\
z +0 z +1 z +2 z +3
░░░░░ ░░░░░ ░░░░░ ░░░░░
░╔░░░ ░▼╚╗░ ░░▼▼░ ░░░░░
░╝░░░ ░▼░░░ ░░░╔░ ░░░▼░
░▼▼░░ ░░░░░ ░░░╝░ ░╚╗▼░
░░░░░ ░░░░░ ░░░░░ ░░░░░

░ : Wall
╔,╚,╗,╝ : Track/Ramp
▼ : Down Ramp (empty space)
}}

Note that this impulse elevator, due to the checkpoint effect and upward curved ramp effect, will not actually result in carts traveling straight up the ramp. They will lose speed, bounce off a ramp, then be accelerated back into the spiral after a 9-turn delay on both tiles on the floor where they are stopped. This is because the checkpoint effect allows carts to travel up the ramps in a single turn, but also prevents the impulse ramps from adding acceleration unless the cart is slowed to staying on the ramp for more than one turn. Initial acceleration will carry the cart up a variable number of floors before this effect occurs, but this bouncing back and forth will occur every 5 z-levels after the first time the cart stops. When the cart ''is'' traveling upwards, it will pass every tile at a rate of one tile per turn regardless of its actual speed, due to the checkpoint effect. In tracks with only a single cart, this is negligible, but when multiple carts are on the same track (such as when you place multiple carts on a magma cart lift) this can cause collisions which derail carts or cause other unexpected or undesired behaviors.

The following impulse ramp (while larger) should alleviate these problems by using a straight ramp to go upwards, preceded by an impulse ramp to exploit the checkpoint effect and negate up ramp costs. Corners still decelerate carts, so the cart will tend towards a velocity of 72k, which is derail speed. Derail speed breaks (see Controlling Speed, below) may be necessary at the top.

{{diagram|spaces=yes|\
z +0 z +1 z +2 z +3
░░░░░░ ░░░░░░ ░░░░░░ ░░░░░░
░░░░░░ ░╔╔═░░ ░░▼▼╗░ ░░░░░░
░║░░░░ ░▼░░░░ ░░░░╗░ ░░░░▼░
░╚░░░░ ░▼░░░░ ░░░░║░ ░░░░▼░
░╚▼▼░░ ░░░░░░ ░░░░░░ ░░═╝╝░
░░░░░░ ░░░░░░ ░░░░░░ ░░░░░░

░ : Wall
║,═,╔,╚,╗,╝ : Track/Ramp
▼ : Down Ramp (empty space)
}}

Also, if you want to have a cart following a below-derail speed, the following track works well:
{{diagram|spaces=yes|\
z +0 z +1 z +2 z +3
░░░░░ ░░░░░ ░░░░░ ░░░░░
░░░░░ ░══░░ ░▼▼║░ ░░░▼░
░║░░░ ░▼░░░ ░░░║░ ░░░▼░
░║▼▼░ ░▼░░░ ░░░░░ ░░══░
░░░░░ ░░░░░ ░░░░░ ░░░░░

░ : Wall
║,═ : Track/Ramp
▼ : Down Ramp (empty space)
}}
In this elevator, the cart collides with the walls in the corners, but then realigns on the ramp, picks up speed, checkpoints through the next ramp, and slams into the next wall. It is slower (10 ticks per floor) but produces reliable speeds, and will exit the impulse elevator at little more than push speeds.

A sort of opposite effect to impulse ramps also exists: ramps lacking the proper "up" and "down" connections are treated as flat track, even if they actually go up or down z-levels. This allows building "anti-impulse" slopes consisting entirely of ramps only connected up, which a minecart can travel up forty levels and more, needing no more than a single push.

=== Controlling traffic ===

==== Switching ====

As constructions or tile features, [[door]]s and other furniture can be built on tracks. A [[door]] or [[floodgate]] can be turned on or off by a [[lever]], effectively controlling the flow of automated minecarts. This may be <s>dangerous</s> [[fun]], however.
{{diagram|spaces=yes|\
->
A ════┤≡════ B
┤ : roller pushing to East
≡ : door
}}
The roller pushes the cart east, but until the "departure condition" is fulfilled, the door remains closed and blocks the path.

[[Bridge]]s can also act as tracks, but only if they're lowered or not retracted. This property can enable levers to turn tracks on and off. However, care should be taken to ensure that such bridges are never operated while a cart is on top of them, as the cart will be flung off the track. It's worth noting that it's often faster, and cheaper, to construct large bridges than long sections of constructed track.

A powered track switch can be constructed by building an "inverted" corner as illustrated below.
{{diagram|spaces=yes|\
B B
║ -> ║
║ ║
════╚═══ ════├════
A C A C
├ : roller pushing to West.
}}

If the cart is pushed East from the stop at 'A' while the roller is activated, it will arrive at 'B'. If the roller is not running, it will arrive at 'C'. The switch works by the roller first reversing the incoming cart's movement and the cart ''then'' following the track corner.

This switch is very reliable, reacts instantly to on/off signals, and carts of any speed can be switched by this design, although very fast carts will require rollers that are several tiles long, up to three. The requirement for power can be inconvenient or impractical. Non-powered solutions may use controlled derailment, or a connecting bridge.
{{diagram|spaces=yes|\
B ╥
║
║
╞════╝ ════╡
A D C
}}
Here the track between A and C is not continuous. The only continuous track is A->B, with a corner (not a T section). Fast moving carts will tend to derail at D and rejoin the track to C. Placing a door at D will prevent the derailment, so the cart continues to B. The door is operated by mechanisms elsewhere (typically, a lever, but some fun can be had with pressure plates).

Since it depends on derailing, this switch requires a very fast cart, faster than what can be achieved with rollers alone. To gain sufficient speed, a cart must be accelerated further, usually by descending several levels or through impulse ramps. The high speed makes the cart much more dangerous and harder to control.

If carts are moving too slowly to derail at the corner, a retractable bridge may be used as a connector between A and C.
{{diagram|spaces=yes|\
B╥
║
║
A╞════bbb════╡C
}}
The bridge must overlap the corner. Bridges behave like a track crossing, allowing carts to pass in a straight line. When retracted, the corner reappears, so the carts will continue to B. Bridges take 100 steps to react to a signal, necessitating rather long "lead times" when switching tracks via bridge.

As mentioned above, special care must be taken to make sure the bridge doesn't change state while the cart is passing over it. Retracting bridges will throw the cart, causing it to stop dead. Raising bridges can even crush the cart.

==== Controlling Speed ====


Minecarts can reach extremely high speeds, especially when descending multiple Z-levels. A minecart will derail at a track corner if its speed exceeds 0.5 t/st (tiles per step), '''unless''' the route in the direction of travel is blocked:

Will derail at > 0.5 t/st:

{{diagram|spaces=yes|\
in ══╗ -> derailing
║
out
}}

Will not derail at > 0.5 t/st:
{{diagram|spaces=yes|\
in ══╗O
║
out

O : wall/column.
}}

This behavior can be used to build a "speed limiter", that will ensure that when a minecart exits it is traveling below derail speed:
{{diagram|spaces=yes|\
░░░░ ░░░░░ ░░░░░
in ═╔═╗░ ░╔S╗░ ░╔S╗░
out ═╬═╝░ out ═╗═╝░ out ═╗═╝░
░╚S╝░ ░╚═╝═ in ░╚S╝░
░░░░░ ░░░░ ║░░░
in
░ : wall
S : Track Stop (High Friction or lower)
}}
If the minecart is traveling below derailment speed, it will not be affected; if above, will be slowed down and checked again. Granted, you could do the same just with track turns, but it may take a lot of turns and time.

Since all the derailings, bounces and ramps can impart a sideway component of speed small enough to start visible drift many tiles away (say, [[Fun|in the middle of a bridge]]), track turns have one more use: forcing the carts to move strictly along the grid directions. Carts passing a turn below derailing speed convert one component of velocity into another, thus eliminating the drift.

=== Loading liquids ===
[[Water]] and [[magma]] can also be loaded into minecarts by submerging them to a depth of at least 6/7 while standing still or moving at speeds of at most 10000. Loading fluids onto minecarts can be difficult because the added friction provided by fluids can stop a cart in a submerged tile. Curiously, filling a minecart with magma does not injure a dwarf ''riding'' it. A minecart will hold enough fluid to increase the depth of a single tile by 2. This amount is listed as 833 units, which weigh 459Γ (water) or 999Γ (magma). An iron or steel cart filled with magma weighs 1313Γ, while an adamantine cart filled with magma weighs 1007Γ. Since you need a minecart above the liquid's level, possible arrangements may include pressure-activated sluices, rollers (with magma-safe chains for magma), pouring from above to "submerge" it briefly on the same level and drain excess away (dig deeper and leave a vaporizer, though if you could have power for rollers, may as well use a pump) and exploits with ramps (not necessarily impulse ramps, "same height" passing dip does it).
The liquids can be dumped by a constructed track stop.

== Quirks ==
This little quirk concerns dwarf-managed minecarts. If a track which was previously open becomes blocked (ex. flipping a switch connected to a floodgate you've built on the track to raise it) and the conditions for departure are met, instead of refusing to ride/guide the minecart or ride/guide it until it reaches the obstacle, the dwarf will pick up the minecart off the tracks and haul it to its scheduled destination on foot. If the distance is long enough and the weight of the cart heavy enough (due to being filled with heavy items such as stones), the dwarf may drop the cart because of fatigue/hunger/thirst before reaching the destination. This will cancel that vehicle setting job and make another dwarf come by and attempt to haul the cart to the nearest appropriate stockpile where another dwarf will pick up the cart and attempt to haul it to its initial stop. If the stockpile is far enough from initial stop, this second dwarf who is attempting to place the minecart on its tracks may also drop the minecart out of fatigue/hunger/thirst creating a loop that will go on until a dwarf with enough endurance manages to place the minecart where it belongs.

In fact, it seems dwarves are more than happy to attempt to carry a minecart from one stop to another even if just waiting until the track is open again would be the more sane option.

Dwarves will also carry a minecart to its next stop if the direction specified is incorrect (or invalid). This can often occur when using the default departure settings and forgetting to set the direction of each condition.

Dwarves can admire buildings while riding mine carts. Dwarves will not fall asleep during a ride (at least not from being drowsy). If riding on a continuous powered track loop, the dwarf will die of dehydration/starvation as they can not jump off to get sustenance{{cite forum|109460/3377228}}. Dwarves riding in submerged minecarts will gain experience in [[swimming]].{{cite forum|129889}}

Tracks block wagon access to trade depots, unless they're on a ramp. [[Bridge]]s can also be used, as they function as tracks but do not block wagons.

== Physics ==


Minecart physics depend greatly on the departure mode set in the route stop conditions.

When set to "Push" or "Ride", minecarts will move according to the regular laws of momentum, gaining speed when going downhill, losing it slowly due to friction when on a flat plane, and more quickly when going uphill. In these modes, minecarts will move in a straight line until they either are brought to a stop by friction or an obstacle, or until they encounter a turn. A minecart will roll straight past "blocked" ends of T-junctions or track ends, they have no power to restrict a cart's movement. The cart's behavior is largely independent of the weight of its contents (including fluids and dwarves): heavily loaded carts gain more momentum when accelerating, but this only plays a role in collisions: a heavy cart gains just as much speed and is as easy to stop as a light one. In either case, dwarves can not push nor ride an unpowered cart up a ramp, bouncing back the direction it came. At best, this is a waste of time; at worst, it will give your cart-pushing dwarf a [[fun|fun surprise]]. To solve this, the player can either use Rollers (see below) or set the cart to be Guided.

The difference between "Push" and "Ride" is whether the dwarf will go along with the cart or not.
{{DFtext|Push}}: the dwarf will give the cart an initial push, not enough to go up a ramp, but enough to go some way along flat track, and the dwarf will remain at the first stop, ready for a new job.
{{DFtext|Ride}}: the dwarf will give the cart the same initial push and then hop aboard the cart riding with it to the next stop.
{{DFtext|Guide}}: minecarts seem to ignore all laws of physics. That is:
*Ignore the weight of any and all items inside. Therefore:
**Move at the speed of the dwarf that is guiding them. It is thus recommended to pick the most [[attribute#Agility|agile]] of your dwarves for cart-guiding tasks.
*Ignore working rollers.
*Will ''not'' collide with other guided carts even when a full frontal collision would be expected.
*Will go up ramps like nobody's business.
This is therefore the recommended method of transport for simple non-powered rail systems, despite it diverting a dwarf from other, potentially more important tasks.

Some samples with behavior:
{{diagram|spaces=yes|\
A <-> B A <-> C A <-> B
B B B
║ ║ ║
A══╝ A══╩══C A══╬╗
You can only go A->B ╚╝
Works when the cart Works
is in Guide mode.
}}
In the second example above, a cart "pushed" from B will go over the junction and roll off into the unknown south.

=== Track Direction Irrelevance ===
Carts that are traveling independently, (that is, not guided,) only care that tracks ''are'' on the tile, not which direction the tracks actually move. Tracks respect only curves (with two exits) and ramps.

This means, for example, that the following tracks, when a (non-guided) cart travels from West-to-East, are functionally identical in effect:

{{diagram|spaces=yes|\
A════════════B A╬║╚╔╣╩╦╠╥╨╞╡B
}}

This is because so far as the cart is concerned, only valid ramps and curves with two exits where there is no exit in the path they are traveling matters.

Hence, if a minecart encounters the end of the track or a T junction with no "exit" in its movement direction, it will simply leave the track and continue on its course in a straight line until it encounters an obstacle, slows to a stop, or encounters another track even if the tile at which it joins the new track instantly sends it around a corner.

In fact, a "║", a "╦", a "╬", and a "╥" are ''only different in appearance'', and are ignored by the cart, which will continue in its current direction, regardless of the track. For any purpose but ramps, ''only curves matter at all''.

Carts only check for curves when they are halfway through a tile. When they get there, they look to see if their path has no exit. (That is, if it is traveling East, it checks if there is an East exit.) If there is, it ignores all other track directions, and keeps traveling. If there is not, it checks to see if there are only two exits to the track, and if one of those directions was the direction it "came from". (That is, if traveling from the East, it checks if there is a valid exit to the West, and if so, if there is either a North exit or a South exit.) If there is not, it ignores the track anyway, and keeps on traveling as though it were still on track. If there is, it will subtract 1000 from the velocity of the cart, and redirect all forward velocity to the direction of the curve. This change in the direction of velocity ''overwrites'' any "diagonal" velocity, which can prevent diagonal velocity derailments, but any perpendicular velocity is not preserved, and is instead discarded.

=== Valid and Invalid Ramps ===
Ramps are functionally defined for cart purposes as being a tile which exerts an acceleration force upon its "downward slope", and which allows connection to tracks a z-level above or below. This downward slope requires a cart to have one ''and exactly one'' carved exit to the tile that is the "bottom" of the ramp. Ramps accelerate carts in this "downward" direction (possibly leading to diagonal movement, below), and the deceleration of an "uphill" ramp is actually just the acceleration being applied against the direction of a cart's movement.

This is where players can find an exploit in the behavior of ramps - if there are ''two'' "downhill" exits to a ramp (such as a "T junction" on a ramp where only one exit faces a wall), then the ramp provides no acceleration ''or'' deceleration, allowing carts to travel up ramps without any loss of momentum except for the standard "flat track" deceleration, because as far as the cart is concerned, the track ''is'' flat. (A T junction is also not a curve, so the track is considered flat and straight no matter what direction the cart is traveling.)

Similar effects can be achieved when there are ''no'' "downhill" exits to a ramp. This may be the case if you have, for example, an East-West track with a one-tile channel with a ramp in it. The cart will travel through the "dip" with no change in velocity. It can also be the case if you abuse the Track Direction Irrelevance, above, and set only exits ''up'' the ramp, and none leading ''down'' the ramp. For example, if a cart is traveling from West to East up a slope, only carving East exits on each tile of ramp will make the cart travel up the ramp, and then recognize the tile it is on as being a "flat" tile, thus ignoring any deceleration from traveling uphill.

Note that this effect only reliably occurs at below-derail speeds as the cart will treat the ramp as an invitation for a ramp jump otherwise. (This almost always results in a collision with a wall that will stop forward progress.)

=== Falling ===
When falling, a minecart appears to cause no damage upon collision, possibly to allow cart "stacking" across Z-levels.{{cite devlog|2012|04|06}} A dwarf riding in a minecart that is dropped multiple z-levels suffers normal fall damage. Minecarts can fall through up/down stairs.

While airborne, carts do not feel the effects of friction in any horizontal direction, and will continue until they strike an obstacle. Carts that land on tracks instantly re-rail themselves regardless of track directionality.

Falling carts accelerate similarly to the way that a ramp will accelerate a cart in a special z-only velocity that only applies to airborne carts. (Actually, acceleration due to gravity in freefall seems curiously slightly ''slower'' than ramp acceleration.) Ramp acceleration, while it logically should be partially z-directional, is only recorded as x- or y-directional, and there is no translation of z-directional velocity upon landing. Landing carts zero out their vertical velocity upon landing, even when landing on ramps, although carts that had horizontal momentum while falling preserve it.

This means a cart falling (from a hatch, thus with no horizontal speed) onto a track ramp is accelerated as if starting from the middle of the ramp - i.e. to the same speed, no matter how many Z-levels it was dropped, vertical velocity is negated. {{cite forum|144328/5701211}}

Carts falling onto a floor can, however, cause damage to creatures ''one tile below the floor''. This can be used in an [[exploit]] called a "thumper", where carts are caused to repeatedly fall on a floor above an entrance to the fort, inflicting significant damage (as though it were a collision) on those below the cart.

=== Cart Jumps ===
Carts that cross off of "up" ramps relative to their current direction of travel, which do not have a ceiling above them, are traveling above derail speed, and do not have valid ramp track before them can translate a portion of their horizontal velocity into vertical velocity, causing a cart to be projected into the air until vertical velocity is negated and overcome by the gravitational acceleration. Because downwards acceleration is applied per-tick, this creates a reasonable facsimile of the parabolic motion of an actual object rolled up a ramp and launched with significant speed.

{{diagram|spaces=yes|\
z0 z0 hiding ramps z+1 A z+1 B (hidden ramp)
▒▒▒▒▒▒▒▒▒▒▒▒ ▒▒▒▒▒▒▒▒▒▒▒▒ ▒▒▒▒▒▒▒▒▒▒▒▒ ▒▒▒▒▒▒▒▒▒▒▒▒
═▲▲▲▲▲══▲▒▲═ ═╚╚╚╚╚═══▒══ ▼▼▼▼▼ ▼═▼ ▼▼▼▼▼ ▼╚▼
▒ : Wall
═ : track
▲ : Ramp
}}
In this diagram, if there is no ceiling above it, the track in z+1 A will launch its carts airborne when they travel across the ramp. z+1 B (with a ramp on the tile on the hill) will not launch the cart. The cart would also not be launched with ''any'' valid ramp, even if it does not travel in an appropriate direction, such as North/South (which the cart will ignore, as it is not a curve, anyway, although it may produce acceleration that may cause diagonal movement.)

Carts that are traveling at derail velocity will also start "jumping" from the track if it hits an un-tracked tile, flying over and ignoring any tracks until it is ready to land. Carts that land upon tracked tiles re-rail themselves, and clever designers use this feature to jump over curved track sections in one direction or another. (Retracting bridges over untracked tiles can cause jumps or not cause jumps depending upon the status of the bridge.) Minecart speed must be carefully regulated to ensure reliability of jump length.

Hitting untracked tiles at around 70k velocity creates a vertical component to acceleration that allows for jumps of around 6 (horizontal) tiles that do not actually leave the z-level the cart is on, but which do apply z-direction velocity on the cart, as per falling.

Carts that approach a downward slope at a high enough velocity will also make a jump, (or rather, ignore the ramp and fly forwards) but will not do so if the Checkpoint Effect (below) is exploited through an impulse ramp before the actual downhill as the impulse ramp "tricks" the cart into thinking it has already started going downhill. The cart will also not fly off the ramp if there is a wall and ceiling preventing any motion but going down the ramp.

=== Skipping ===
If a minecart is moving fast enough, it can skip over [[water]] or [[magma]], making splashes of [[mist]] (or [[magma mist]]) as it attempts to move on them horizontally. This horizontal movement is independent of the minecart and its content's [[weight]].

Skipping causes significant friction on the cart, and even a cart going at max speed from ramps can only make about 50 tiles without requiring re-acceleration. (Carts that decelerate enough that they do not trigger the skipping effect will, of course, sink.)

=== Corner Ramp Derail ===

Corners on upward ramps can cause diagonal movement, forcing a derail even if the cart has a wall next to it, which will force a stop when it touches a wall that forces dwarves to manually reset the cart.

This is caused by the fact that a cart, after turning the bend in the track halfway through the length of the tile, will still "accelerate down", which is now perpendicular to the movement of the cart, causing acceleration to occur in two directions. (Down corner ramps do not have this problem, as when they pass the halfway point, all perpendicular motion is added to forward motion, and after that curve, all downward acceleration is in the forward direction.)

There are two fixes to this problem. One is to simply not put corners on up ramps. The other is to take advantage of the Checkpoint Effect, below, by making a ramp (possibly including an impulse ramp) one tile in front of the ramp to make it skip through most of the tile before sideways momentum can be built.

=== Checkpoint Effect ===
The checkpoint effect, [http://www.bay12forums.com/smf/index.php?topic=144328.0 explained in depth by Larix], is an odd and highly exploitable feature of ramps where minecarts "teleport" through the next tile of track, ignoring nearly all minecart physics (except that they stop at all walls or other obstacles and only respect curves with no backing wall and invalid ramps if they are below derail speed) and passing through that tile in just a single tick, and into the next tile at the halfway point.

This effect occurs when a cart leaves a downward ramp for any other direction of tile. (This includes ramps which accelerate in different directions, even a ramp which goes from accelerating East to accelerating North due to a bend in a chain of standard down ramps in a curve.) This allows, for example, two valid straight ramps directly next to one another with a cart dropped onto one or the other with no momentum to have the cart pick up acceleration going "down" the ramp as normal, but then flying up through the "up" ramp it travels into with no loss of momentum, as though it had come from an impulse ramp. If the two ramps had at least one space of distance between them, and then a cart were dropped in, the cart would instead "rock" back and forth between the two ramps.

This seems to be because ramps have a slightly longer length than regular tiles - 144,000, rather than 100,000 distance. When this "snaps back" after a ramp, it seems to project the cart suddenly further along the track, making it jump a tile ahead even when otherwise moving at relatively low speeds.

This [[bug]] is the cause of a ''wide array'' of unexpected behavior among people who do not take this bug into account. It causes derailments or failure to climb up seemingly valid impulse elevators. In general, it makes a system that behaves extremely counter-intuitively, and operates ''any time a cart encounters a valid ramp''. At the same time, when its effect is accounted for, it is highly exploitable: It causes "perpetual motion devices" using no power when two opposing ramps are placed next to one another, since the "uphill" effect of the opposing ramp is ignored, preventing deceleration.

Another useful thing to note about this exploit is that carts traveling at no less than 72,000 or so speed (enough to travel half a ramp tile in a single tick) can travel through every tile in just one tick at no change in velocity as long as the tiles alternate between impulse ramp or actual down ramp and any other tile type. The cart checkpoints through the non-down-ramp tiles, and can pass through the (impulse) down ramp tiles in a single tick, before they can actually start gaining momentum.

{{diagram|spaces=yes|\
▒▒▒▒▒▒▒▒▒▒ ▒▒▒▒▒▒▒▒▒▒
═▲═▲═▲═▲═▲═ ═╚═╚═╚═╚═╚═
▒ : Wall
═ : Normal track
▲/╚ : N/E Track/Ramp
}}

If the cart enters from the West at less than 72,000 speed, some of those ramps will cause Eastward acceleration.

This means that an impulse ramp not contiguous to other impulse ramps has a top speed of around 75k:

{{diagram|spaces=yes|\
▒▒▒▒▒ ▒▒▒▒▒
▒╔═╗▒ ▒╔═╗▒
▒╚▲╝▒ ▒╚╗╝▒
▒▒▒▒▒ ▒▒▒▒▒
}}
This setup makes a cart that travels clockwise at a speed that fluctuates around 75k velocity. If the cart has more than 72k velocity, it fails to accelerate in the ramp, as it leaves the ramp in a single turn due to checkpointing to the halfway point. After that, the curves sap 1k velocity, and every tick saps 10 velocity.

Two contiguous impulse ramps with a same-facing "downwards slope", however, do not suffer the checkpoint effect in the second tile, giving functionally triple the space to accelerate. This means it will add velocity (at the standard rate of 4.9k per tick) up to a maximum speed of 216k.
{{diagram|spaces=yes|\
▒▒▒▒▒▒ ▒▒▒▒▒▒
▒╔══╗▒ ▒╔══╗▒
▒╚▲▲╝▒ ▒╚╗╗╝▒
▒▒▒▒▒▒ ▒▒▒▒▒▒
}}
This example results in a cart moving three times as fast as the previous cart.

Three successive ramps results in the highest attainable speeds.

In practical terms, this means that only consecutive ramps should be used for high acceleration, but singleton ramps can be used to have speeds that are somewhat regulated.

=== Stacking ===
If a minecart lands on top of another minecart, they may form a stack, with the upper cart on the z-level above the lower. Subsequent carts do not form a stack, but rather quantum stockpile in the same space. This behaviour is useful for [[megaprojects]] and [[trap design]] with minecarts as the weaponry. Moderation should still be exercised: carts take longer to fall into a "stacking" tile already occupied by other carts and will spend that time "hanging" in the air above the stack. This can lead to following carts striking them, which can cause all kinds of malfunctions. The extra time is two game steps for every cart already in the stack, which doesn't hurt stacks of ten carts very much but makes stacks of 100+ rather impractical.

These minecarts on the upper level generally need to be struck with another minecart to move out, or have their support removed. The latter option is safest done by shooting it away with another minecart, manual removal of a stack-supporting cart typically causes the next cart from the stack to [[fun|fall on top]] of the hauler.

=== Perfectly Elastic Collisions ===
Minecart collisions are perfectly elastic, meaning that not only do minecarts not take damage, but that two carts that are rolling which have frontal collisions of near-similar speed, and where one cart is no more than twice the mass of the other cart, will result in a billiard-ball-like effect of the lighter cart bouncing off the heavier cart with a proportional speed increase dependent upon the relative momentum behind the heavier cart.

Using this trick with carts already at the 270,000 maximum speed from ramps can result in "supersonic" carts traveling at speeds in the millions (travelling a dozen tiles per tick), but where they are suddenly subject to 10,000 units of "terminal velocity" friction per tick. [http://www.bay12forums.com/smf/index.php?topic=137557.0 Thread with SCIENCE here].

While hypothetically capable of launching a minecart into orbit when used in conjunction with a ramp, no cargo can be contained in the launched cart, as the collisions will force ejections of the cargo. Your "unwilling volunteer" [[goblin]] space pioneers will simply become paste underneath the wheels of an extreme high-speed cart.

=== Numbers behind the scene ===

According to early research by '''expwnent'''{{cite forum|112831/3536975}}:

The minecart has a variable for speed. Speed is measured in tiles/100000 ticks, so a speed of one hundred thousand means one tile per tick. By going down a large number of ramps, a maximum speed of 270,000 can be reached, which presents the limit for most practical applications. Short bursts of (much) higher speeds are possible through carefully planned collisions of high-speed carts {{cite forum|137557/5145499}}.

Every tick the cart accumulates distance units, as well as slows down depending on current tile (speed is reduced by "friction" of the tile). The cart will move to the next tile the tick before accumulating 100000 distance units, (or several tiles in case of great speed), then the leftover distance units are added to the default 100000 distance u. of the next tile. Since most deceleration and acceleration is applied per step, with the notable exception of corners, a cart going at twice the speed of another one can cover about four times the distance in a straight line, but only twice the distance along a winding track with very many corners.

A push will teleport a cart to the beginning of the next tile (NOT the middle!) in one tick with 19990 speed (10 speed is lost due to track friction), while a roller will give a cart the roller's set speed, and it will start to accumulate regular track friction past the middle of the roller tile. Some track features will affect a minecart when it is past the middle of the previous tile: entering a ramp or a hole/drop will happen when the cart has left the middle of the previous tile, and the ramp will gain additional distance unit depending on the leftover units from the previous tile. When a cart leaves a ramp it will emerge after one tick in the middle of the next regular tile, so its entry coordinate is "50000-speed+friction". Rollers also affect the speed of minecart from the middle of the previous tile.

Friction of tiles:
{| class="wikitable"
|-
! Tile
! Friction
! Comment
|-
| Tracks
| 10
|-
| Ground/Floor
| 200
|-
| Unusable ramp
| 10
|-
| Upwards ramp
| 4910 (10+4900)
|-
| Downwards ramp
| -4890 (10-4900)
|-
| Roller
| ±100000 (but capped by the set speed)
|-
| Corner track
| 10
| Speed reduced by 1000 upon leaving the corner tile
|-
| Track stop (highest)
| 50000
|-
| Track stop (high)
| 10000
|-
| Track stop (medium)
| 500
|-
| Track stop (low)
| 50
|-
| Track stop (lowest)
| 10
|-
| Water 1-6
| Additional (WaterLevel - 1) * 100
| rowspan="2" | [[#Skipping|See Skipping]]
|-
| Magma 1-6
| Additional (WaterLevel - 1) * 500
|-
| Empty space
| 0
|}

Water of depth 7/7 provides a friction of about 10000 per step, as does maximum-depth magma. This higher friction may not apply to very slow-moving carts.

Impulse sources:
{| class="wikitable"
|-
! Feature
! Speed
|-
| Push
| 20000
|-
| Roller lowest
| 10000
|-
| Roller low
| 20000
|-
| Roller medium
| 30000
|-
| Roller high
| 40000
|-
| Roller Highest
| 50000
|-
|}

== Non-standard uses ==
Minecarts include some interesting characteristics that have motivated uses beyond hauling. They can be useful for creating fully-automated [[exploit|quantum stockpiles]] and [[garbage disposal]]s. Storing perishable goods (meat, meals, etc.) inside a minecart appears to guard against rot and vermin.
Minecarts can be [[Trap_design#Minecarts|used as weapons]], or as (hopefully non-fatal) triggers to restart stalled [[healthcare]]. They can also be used to time/control game events, either using a basic [[repeater]] or much more advanced [[minecart logic]].
Minecarts trigger [[pressure plate]]s, which means a trap can be designed to trigger when a thief attempts to steal a minecart.
A pressure plate can be used as automatic and more precise custom "launch when full enough" system - as long as weight of your minecarts stays the same. You cannot build a hatch or roller on the same tile, so launch by bumping with another cart. {{cite forum|15096/4580050}}
Dwarves riding minecarts can attack enemies within reach (which goes back to dev log). This applies to shooting, and they actually can hit targets while riding by.{{cite forum|109460/5266119}} Whether a minecart protects the rider and how it interacts with dodging is not known yet. Minecart riders can also [[Swimming#Minecart_training|train swimming]] and [[Megaprojects#Surveillance_Track|detect ambushers]].

== Adventure mode ==
In addition to being used for hauling, minecarts can also be ridden in [[adventure mode]]. (Adapted from forum thread {{cite forum|122903/4258212}})

# If the minecart is in your inventory, drop it. If it is already on the ground, proceed to step 2.
# Press {{k|u}} when you are 1 tile away from the minecart (or standing on the same tile as the minecart).
# You will be presented with the following options:
[[File:minecart adventure mode menu.png|left]]
{{clear}}
* If you {{DFtext|Push}} the minecart, it will move a few tiles in the direction you chose. Physics comes into play here, so it will gain/lose speed depending on the usual factors.
* If you {{DFtext|Ride}} the minecart, you will hop into the minecart, even if you were a tile away, and it will move in the chosen direction with you in it. It will gain/lose speed depending on the usual factors. Whilst the minecart is in motion, you should press {{k|.}} to skip your turn; if you attempt to move whilst the minecart is still in motion, the laws of physics come into play, and you will take [[wound|damage]]. Alternatively, you can push the minecart whilst it's still in motion (although it's unclear how one can bend [[physics]] so as to push a moving minecart whilst inside the minecart). If you push it in the same direction you are already travelling in, you will greatly increase the minecart's velocity. You can also push it in different directions, and this will cause it to gradually change direction-the amount of pushes this requires depends on the minecart's velocity. Once the minecart has stopped moving, you may move out of it safely, or you may want to give it another push. Note that if you push a minecart right after having ridden it (still on the same tile as the minecart), it will act as though you chose to ''ride'' it.

If you want to test this out without creating an adventurer, the [[object testing arena]] allows you to spawn minecarts ({{k|k}}-{{k|c}}-{{k|n}})

== Forging and Melting ==
* Metal minecarts cost '''two''' [[metal]] bars to forge, or '''six''' [[adamantine]] wafers.
* When a non-adamantine metal minecart is melted down, it will return '''1.8''' metal bars, for an '''efficiency of 90%'''.
* When an adamantine minecart is melted down, it will produce '''1.8''' wafers, for an '''efficiency of 30%'''.

== See also ==
* [http://www.bay12forums.com/smf/index.php?topic=109460.0 The "How Does Minecart" Thread] by '''Girlinhat''' et al.
* [http://www.bay12forums.com/smf/index.php?topic=112831.0 SCIENCE: Quantifying minecart physics] by '''Snaake''' et al.
* [http://www.bay12forums.com/smf/index.php?topic=129676.0 How to build a Multi-cart Ore to Magma Minecart Project without needing power] by '''WanderingKid'''.
* [http://www.bay12forums.com/smf/index.php?topic=144328.0 My very own Minecart Education Thread. Ten Lessons, now complete.] by '''Larix'''.

== Bugs ==
*A dwarf will drop her [[child|baby]], if she has one, when boarding a minecart set to be ridden.
*Dwarves have no concept of traffic safety and will walk into busy minecart lines to retrieve objects, often with deadly consequences. This is especially problematic in [[Swimming#Minecart_training|clever applications]] depending on dwarves riding the carts very frequently, because they have a bad habit of dumping their worn clothes on the tracks after a minecart ride. Adding an automatically-operated [[hatch cover]] at the end of such a ride can help prevent [[unfortunate accident]]s.
*Dwarves cannot guide a minecart through an unlocked door unless another dwarf opens the door.{{bug|6056}}
*It is possible for a creature and minecart moving towards each other to pass without collision if they exchange tiles in the same tick.
*After a minecart ride, a dwarf will sometimes haul the minecart to a storage stockpile, leaving another dwarf to haul the vehicle back to the route.
*Minecarts falling onto a floor injure creatures in the tile below the floor.{{bug|6068}}
*A minecart's initial velocity is not affected by weight, when pushed or launched from rollers.{{bug|6296}}
*Removing a stop that has a vehicle waiting on it may cause the game to crash.{{bug|5980}}

{{Category|Fortress mode}}
{{Category|Interface}}

[[ru:Minecart]]

Minecart

2015-06-20T14:25:55Z

NW Kohaku: /* Checkpoint Effect */ correction

{{Quality|Masterwork|08:15, 19 May 2015 (UTC)}}
{{av}}
A '''minecart''' is a [[tool]] intended for [[hauling]], introduced in version 0.34.08. It can be made of [[wood]] at a [[carpenter's workshop]] or [[metal]] at a [[metalsmith's forge]] (using the [[Metal crafter|metalcrafting]] labor.) Minecarts store up to five times as many items as [[wheelbarrow]]s and are quite a bit faster than dwarves hauling objects by hand, but have the disadvantages of requiring a dedicated track network, a complex route planning phase, and the possibility of dwarves [[Fun|blundering into the path of carts filled with lead ore]]. Tracks may be carved into stone, or [[Construction|constructed]]; the latter allows above-ground routes, but these are more difficult to set up due to their additional [[building material|material requirements]].

Just like wheelbarrows, minecarts are considered [[item]]s and are stored in a [[furniture]] [[stockpile]]. Despite their five-times-greater capacity, they are only 33% larger than wheelbarrows and are identical in base [[item value|value]] when made from the same [[material]] (the value may differ due to the [[item quality]]). [[thief|Thieves]] or even mischievous animals can steal minecarts, even when they are moving on a track{{cite forum|109460/3289070}}. However, minecarts moving fast enough or being ridden cannot be stolen.

Although most of the utility of minecarts is in [[fortress mode]], an [[adventure mode|adventurer]] can also ride in a minecart. Adventurers can also pick up and relocate minecarts.

The invention of minecarts revolutionized the [[minecart logic|Science of Dwarfputing]] by enabling smaller, faster logic systems to be built.

== Basic Minecart Usage ==
Minecarts can be used to swiftly transport dwarves, [[flow|fluids]], and/or large amounts of items, but before you have a functional minecart there are several preconditions that need to be met. First of all you need an actual minecart, constructed either in a [[carpenter's workshop]] or [[metalsmith's forge]]. For the minecart to be able to move you also need to carve (with {{k|d}} {{k|T}}) or construct (with {{k|b}} {{k|C}} {{k|T}}) a track, which could be as simple as a straight line. Finally you need to construct stops on your track (with {{k|b}} {{k|C}} {{k|S}}) where the minecart will start and stop.

After you have created the stops and assigned a cart to the track, you must create logic routes connecting several stops and designate starting conditions for each stop. This is done with the {{k|h}}auling key. The most basic conditions are how the cart's movement is initiated and in which direction the cart should start moving. Carts can be either be Pushed (a dwarf stands at a stop and gives the cart a single push) or Guided (a dwarf continually pushes the cart forward, guiding it along the track). The [[hauling]] [[labor]] required for pushing and guiding carts is called "Push/Haul Vehicles" and is turned on by default.

To control which items to transport you can add conditions specifying: (1) which kind of items to be loaded, and unloaded, (2) stockpile links to define which stockpile(s) the items should be un/loaded to and from.

===Capacity and weights ===
Minecarts have five times the [[Weight|capacity]] of [[wheelbarrow]]s.

'''Examples of the capacity of one cart'''
{| class="wikitable"
|-
! Item
! Amount
|-
| [[stone]]
| 5
|-
| [[wood|log]]
| 10
|-
| [[block]]/[[bar]]
| 83
|-
| [[Kitchen|prepared meals]]
| 500
|-
| [[Trap_component#Spiked_ball|spiked balls]]
| 500
|-
| [[Weapon#Native_weapons|mace]]
| 625
|-
| [[Weapon#Native_weapons|spears]]
| 1250
|-
| [[cloth]]
| 2500
|}

The weight of the loaded minecart does not affect the initial velocity received from pushing or launching from a roller. However, the load of a minecart ''does'' affect whether a [[pressure plate]] triggers or not, based on the pressure plate's setting.

'''Weights of different carts'''

{| class="wikitable"
|-
! Type of cart
! Empty cart
! Fully loaded (items)
|-
| oaken minecart
| 28Γ
| 378Γ (10 oak logs)
|-
| platinum minecart
| 856Γ
| 10482Γ (83 gold bars)
|}

The weight of a minecart is one twenty-fifth (1/25) the [[density]] of its material in Urists. Because pressure plates can be set to trigger at intervals of 50 Urists, minecarts with weights just under a multiple of 50 are ideal for switching based on whether they're full or empty. The best minecart materials for full/empty switching are as follows:

{| class="wikitable sortable"
|-
! Material !! Minecart weight !! Content weight required to trigger !! Banana roasts required to trigger (for scale)
|-
| [[Bismuth]] (moods only) || 391 || 9 || 15
|-
| [[Brass]] || 342 || 8 || 14
|-
| [[Electrum]] || 596 || 4 || 7
|-
| [[Fine pewter]] || 291 || 9 || 15
|-
| [[Glumprong]] || 48 || 2 || 4
|-
| [[Lay pewter]] || 291 || 9 || 15
|-
| [[Nickel silver]] || 346 || 4 || 7
|-
| [[Tin]] || 291 || 9 || 15
|-
| [[Trifle pewter]] || 291 || 9 || 15
|}

=== Creating tracks ===
Minecart tracks are made up of contiguous track, tracked ramp, or bridge tiles. Track tiles and tracked ramp tiles have a direction or series of directions associated with them. These directions dictate which directions a minecart on a given tile may move from that tile. For example, a Track NE (northeast) tile allows a minecart on it to move either north or east from its present position. Therefore, if you want your minecart to move east along a straight piece of track, then return west using that same track, you would need to use EW tracks so that the cart could travel east initially, then return west over the same track. Excluding designs in which the cart will "jump" tracks via a drop or other ramp, tracks must be valid end to end to work for most looped or straight-track applications. A single east only track tile in your line of east-west tracks will cause any route using the track to fail the moment it tries to go the wrong way over that tile. Minecart tracks can be built in two ways: Engraved/carved or constructed. A given minecart track need not use engraved or constructed elements exclusively, as the two methods can be used interchangeably depending on the needs of a given section of track. The way the tracks are built is slightly different between the two, as explained below.

====Simple tracks====

'''Carved'''

A single-tile wide strip of natural stone can be designated to be [[Engraver|carved]] (with {{K|d}} {{k|T}}), which will create a straight two-way track. The creation of corners, crossings, and T-junctions is as simple as designating another strip of track that overlaps an existent or newly designated track. Engraved tracks are removed by [[smoothing]] the rock they're on, which results in a smooth floor (that can be re-engraved if necessary), or by building a [[floor]] on top and subsequently removing it. Dwarves can carve corner tracks in one pass by designating the track carving twice and canceling unwanted carvings (with {{K|d}} {{K|x}}). Tracks can be engraved in any natural floor tile, rough, smooth and even over engravings, providing an easy method to remove low-quality or undesired floor engravings. Once a track has been engraved, it's important to check the track directions for each tile in the route carefully to make sure no mistakes were made by yourself or the game's track engraving logic.

'''Constructed'''

Tracks can also be built as regular [[construction]]s (through {{K|b}} {{K|C}} {{K|T}}). This method is resource-expensive, since each track tile requires one stone, [[bar]], or [[block]] for construction, and time-consuming, since you can't designate strips longer than 10 tiles at a time. Corners, crossings, T-junctions, and ramps also have to be designated individually. However, it is usually the only way to build tracks above ground or on soil (barring the [[Obsidian farming|creation of obsidian]]). Constructed tracks are designated for removal like any regular construction; be aware that removing track ramps built on top of natural ones will also remove the original ramp, leaving a flat floor.

====Ramps====

'''Carved'''

The carving of natural ramps is a little more confusing: to carve a two-way track on a ramp (natural only, does not work on constructed ramps), you must designate the track '''starting on the ramp and one square beyond''' in the direction you want the track to go. For the side of the ramp square you want to head upward, there '''must''' be either a natural or constructed wall in the square next to it, otherwise the game assumes you are trying to carve it on the same level -- this can result in the track being carved underneath a door or other object. If you have accidentally done this, you can correct it by smoothing the ramp and constructing a single square of wall next to it, then re-carving the ramp correctly. (However, the wall must stay there permanently; removing it will disconnect the track.)

'''Constructed'''

When constructing track ramps, the stated direction should be the same as the connected tracks. For example, a track going up from West to East would require, starting from the West, a Track (EW), a Track/Ramp (EW) and a Wall behind the ramp, underneath the section of track above it. Incorrectly placed ramps result in minecarts ignoring the ramp and crashing into the supporting wall. They will not, however, display as unusable as when the supporting wall is missing.

'''Examples of ramps'''

A simple ramp would look like this:
{{diagram|spaces=yes|\
z +0 z +1
░░░░ ░░░░
═▲o ░▼═
░░░░ ░░░░
o : wall
}}

Carving track corners into ramps is rather unintuitive and complicated. Since engraving tracks always requires two tiles to connect in a straight line as input, you have to give two separate designations for a single job: a track bit from the ramp tile to the "below" direction and another one to the wall of the "upward" direction. If you wanted to change direction on a ramp from east to north:
{{diagram|spaces=yes|\
z +0 z +1
░░░░░ ░░░░░
░░░░░ ══╗░░
=▲░░ ░░▼░░
░░░░░ ░░░░░
}}
you would need to connect the ramp on z +0 both to the west and to the north by issuing two "carve track" commands, one selecting the ramp and the track tile to the west, and another connecting the ramp tile with the wall to the north. An engraver would then carve a NW track corner into the ramp, allowing carts to pass the corner correctly both going up and down. Such track corners are perfectly serviceable for guided carts, but moving down a route of several of them by pushed or ridden cart is problematic - ramps on corners behave very counter-intuitively, resulting in loss of speed when going down and diagonal movement when going up.

Moving to and from ramps (or between ramps "pointing" in different directions0 causes some non-trivial adjustments to speed and even moving along the tiles at a fixed speed ''unrelated to the entry/exit velocity values'', because transitions to/from ramps are processed differently and are not to be "skipped". This affects compact track/ramp combinations (such as e.g. a simple 2x2 ramp spiral) most, and combined with bouncing often makes them work not in the way one could expect. {{cite forum|144328/5705102}}

{{anchor|Tracks}}

=== Hauling route ===
A hauling route is a list of directions describing how and under what conditions a minecart will move. The proper setting up of routes is essential for a working rail system. Routes, stops, departure conditions and stockpile links are managed from the {{k|h}}auling menu.

==== Route ====
A route defines the path a minecart will take along a track, as well as under what conditions it will move or stop moving. A route is made up of stops. Stops are precisely what they sound like, a position on the track at which you want a minecart to stop. A minecart track might use as little as a single stop for a looped track, which will serve as both a starting and stopping point for the cart, or it could contain many stops, perhaps to load supplies or wait for a bridge to be manually lowered, before reaching its destination or returning to its starting point. It is important to note that you only need to place stops on a route where you actually want the cart to stop and wait for some action to occur. They are not needed to help navigate the cart along the track beyond telling it where on the track to stop.

New routes are created with the {{k|h}}auling key. Existing ones can be removed (without confirmation) with the {{k|x}} key, and also {{k|n}}icknamed. Before operating, the route must have a {{k|v}}ehicle assigned to it (this can be done with either the route or a stop selected). Assigning a full minecart to a route may result in a slow hauling job if the contents are heavy.

==== Stops ====
Stops are the individual waypoints that make up a hauling route. A given stop consists of the location of a tile, as well as conditions describing when, where, and how a cart should be moved after being stopped at that tile. Stops can be created from within the {{k|h}}auling menu, by placing the cursor over a tile and hitting {{k|s}} while highlighting the route (or a stop within) you've already designated. A minecart will begin its route at the first stop created, and continue through each subsequent stop, being guided, pushed, or ridden from each stop to the next depending on the conditions specified. In many basic minecart applications, the cart will end up at the same stop it began at, though this is not always the case. It is important to note that hauling stop order is enforced, even if there is no track. A dwarf will drag the cart overland back to a skipped stop in the route's list if your tracks bypass it somehow.

Once a stop has been placed, it is given a default set of conditions under which to move the minecart if it is stopped there. Each new stop gets the same default conditions regardless of the track it is placed upon (e.g. guide the cart to the north). For this reason new stops might get marked by yellow exclamation marks ({{DFtext|!|#ff0}}) due to invalid directions. One important thing to note is that as you place additional stops, the display will show paths between the stops you have defined. However, this is '''not''' necessarily the actual route the minecart will take once the route is in operation. For example, if a route were defined with two stops at opposite ends of a track with many twists and turns, a line will be drawn directly between those stops to show the order in which they will be visited. These route lines may crisscross all over the tracks, but so long as the track is valid end to end, the cart will follow the track from one stop to the next, even across twists, turns, and z-level changes. Stops, which are the steps that make up a route, should not be confused with Track Stops, described below.

===== Stockpile links =====
By placing the cursor on top of a stockpile and using {{k|s}}, you can create stockpile links while defining a hauling stop. Links can also be redefined by selecting them, placing the cursor over a different stockpile, and pressing {{k|p}}. The cart will then be filled by items present in its various linked stockpiles in preference to other items. Note that bins should be used with caution in stockpiles that are linked to minecarts. Bins cause problems when used with the "Desired Items" list in a stop's conditions. For example, if a minecart is set to accept only granite blocks, and to depart north when it is 100% full of granite blocks, it will not depart if any of those granite blocks are in bins, even if bins are also included in the desired items list. Two solutions to this problem exist as of v0.40.24. First, bins can be disallowed in stockpiles that are linked to stops. Alternatively, bins '''can''' be used in conjunction with minecarts provided that the minecart's departure conditions use only "any items" instead of "desired items." This option can be toggled in the advanced conditions menu for a stop, accessible via the {{key|C|}} key. The cart's contents can still be controlled by specifying what items are allowed in the linked stockpile.

===== Departure condition =====
Departure conditions involve setting conditions in which the minecart will leave on the route. Each condition includes:
# A departure mode (Guide, Ride or Push).
# An initial departure direction (NSEW). Note that this defines the initial direction of movement only. Even if a track includes many turns, as long as the initial movement direction is valid the cart will follow the minecart track thereafter.
# A timer, before which the departure condition cannot be met.
# Conditions on the amount of items in the cart.
Departure conditions are created with the {{k|n}} key. A new departure condition will read: "guide north immediately when empty of desired items". This condition can be changed between basic presets with {{k|c}}. "Advanced" mode ({{k|C}}) allows for more precise control over departure conditions: fine tuning the percentage from 0 to 100 in 25% steps ({{k|f}} and {{k|F}}), switching it being either the maximum or the minimum amount of items for the condition to be met ({{k|m}}), and whether the cart accepts all or only a specific set of items ({{k|l}}). Common to both screens are the departure mode ({{k|p}}, Push, Ride or Guide), {{k|d}}irection, and timer ({{k|t}} and {{k|T}}) options.

To have a cart only carry a specific set of items, the stop can be set to only carry "desired" items, opening the selection screen with the {{k|Enter}} key while having said stop condition selected, and toggling as desired, or it can simply be linked to a stockpile and set to depart once it is full of items from its linked stockpiles, regardless of type.

=== Track Stops ===
A Track Stop, not to be confused with a route stop, is an optional, single-tile construction which serves two purposes. First, it can be used to cancel a cart's momentum in order to slow or stop it as it passes over the Track Stop. This might be necessary if a cart were pushed down a series of ramps to its destination. Second, a Track Stop can cause a cart to automatically dump its contents as it passes over the Track Stop. Track Stops are constructed via {{k|b}} {{k|C}} {{k|S}}, and must be constructed atop an existing piece of track. If a Track Stop has been set to automatically dump a cart's contents, the cart will dump its contents in the direction indicated when it passes over the Track Stop. Depending on the friction settings chosen for the Track Stop, the cart might then stop after dumping, or it might continue on its route to another destination.

Track Stops are not mandatory; in fact, their main use is in automated rail systems. However, even in basic rail systems it can be useful to set a Track Stop to dump items: this saves time that dwarves would otherwise spend in removing items from the cart, time that is better spent driving the cart back to where it's needed. Dumping will occur even with a guided cart. '''Take care not to set Track Stops at a loading site to dump their contents''', or dwarves will never be able to fill the cart. It will dump any contents the moment they are loaded.

Counter-intuitive to their construction method, Track Stops are considered [[building]]s and must be removed by {{k|q}} {{k|x}}.
* See [[#More_on_Track_stop |More on Track Stops]]

=== Step-by-step tutorial ===

Let's construct a simple minecart route. This route will move stone blocks from an input stockpile to an output stockpile. We'll begin by creating the stockpiles:

[[File:minecart-example-1.png|Stockpiles designated.]]

The input stockpile is on the left; the output stockpile is on the right. We'll be moving blocks from left to right. Disable bins in both stockpiles, and set the input stockpile to accept only from links. Then make the stockpile take from the mason's workshop where the blocks are being produced.

Next, carve the track:

[[File:minecart-example-2.png|Track carving designation.]]

Note that the ends of the designation are uniquely shaped; this is automatic, and not anything you need to control. Now, wait for your engravers to come along and carve the track into the stone. (Your haulers will probably also fill up the input stockpile while you wait.)

In addition, while we're waiting for that to happen, we'll build an iron minecart in the forge.

[[File:minecart-example-3.png|Track carved.]]

When the track has been carved, it will look like the above (the track will be solid instead of flashing). Now, order a track stop to be constructed next to the output stockpile:

{|
| [[File:minecart-example-4.png|Track stop designation.]]
| [[File:minecart-example-5.png|Select dumping direction.]]
|}

You must press {{k|d}} three times to select the dumping direction ''before'' placing the track stop. We want our blocks to be dumped into the output stockpile east of the track stop. Then wait for a mechanic to come along and build the track stop.

[[File:minecart-example-6.png|Track stop constructed.]]

Now we'll define the actual ''route''. This is done in the {{k|h}}auling menu. Press {{k|r}} to begin defining a route. Next, move the cursor to the input end of the track, and then press {{k|s}} to define the first stop:

{|
| [[File:minecart-example-7.png|Stop 1 designation.]]
| [[File:minecart-example-8.png|Route definition, in progress.]]
|}

Move the cursor again, to the output end of the track, and press {{k|s}} again to define the second stop:

{|
| [[File:minecart-example-9.png|Stop 2 designation.]]
| [[File:minecart-example-10.png|Route definition, two stops.]]
|-
|
| [[File:minecart-example-11.png|Stops are not defined yet.]]
|}

There are several user interface features to note at this point. The stops have been positioned, but they haven't been ''defined'' yet, so there is a warning {{DFtext|!|#ff0}} symbol by each of them. In the lower right corner, we see what the {{DFtext|!|#ff0}} means. Also, note that the second stop is labeled in white, while the other two lines are grey. The white text is a selection indicator, and can be moved up and down by pressing {{k|+}}/{{k|-}}.

Next we need to define what our stops do. We want the minecart to be filled with blocks at the first stop, then travel to the second stop where it will dump its cargo, and then return. Press {{k|-}} to move the selection up to stop 1, and {{k|Enter}} to open it up. By default, the stop has three conditions:

[[File:minecart-example-12.png|Default stop definition.]]

We don't want any of these, so press {{k|x}} three times to delete them. This leaves us with a blank stop. Now we can add the conditions we actually want. Press {{k|n}} to begin adding the first condition, then {{k|d}} twice to change the direction from north to east. Then press {{k|c}} to change the condition from empty to full. This will instruct the minecart to be guided east when full of desired items.

To set the desired items, we create a stockpile link. Press {{k|s}}, then move the cursor to the input stockpile, then press {{k|p}} to select that stockpile. Now press {{k|Enter}}; this opens up a selection screen that resembles the stockpile customization screen. Move down to Blocks, {{k|e}}nable them, then (if you wish) restrict it to stone blocks.

When you've done all that, stop 1 should look like this:

[[File:minecart-example-13.png|Stop 1, defined.]]

Stop 2 is much simpler. All we need to do is have the minecart return to the input stop. So, make a condition and change the direction:

[[File:minecart-example-14.png|Stop 2, defined.]]

Finally, we just have to assign our minecart. Go back to the route definition screen, and press {{k|v}}. Select the minecart, and press {{k|Enter}}.

Now we've got everything set up:

[[File:minecart-example-15.png|Route, fully defined.]]

The V is red because the minecart hasn't been moved onto the track yet. Some dwarf will have to haul it from the forge to the first stop, by hand; this will take a while, especially if the forge is far away.

Once the minecart is in place, dwarves should fill it with blocks from the input stockpile, which will in turn be filled with blocks from the workshop where your mason has been toiling dutifully. When the minecart is full, the blocks will be dumped into the 1x1 stockpile on the right. Automatic quantum dumping!

=== Troubleshooting ===

Because of the complexity of the system, all but the most careful and experienced minecart users will encounter issues. Most route issues can be diagnosed and fixed from the {{k|h}}auling menu.

'''Symptom:''' {{DFtext|! Set dir/connect track|6:1}} message appears to the right of one or more stops

'''Possible Causes:'''
* The departure direction of the stop might be invalid. Edit the stop using {{k|Enter}} and press{{k|d}} until it is pointing in a valid direction.
* The track stop might not be built on top of a track. The track stop must be deconstructed to remedy this issue.
* Your track might not be built correctly. Make sure all connected tracks between destinations are not one-way tracks.
** This can be especially confusing with ramps. To carve a two-way track on a (natural) ramp, you must designate the ramp and one square beyond in the direction you want the track to go.
** Ramps '''must''' have a solid block on the side opposite to the track, or they will neither work nor be marked as "unusable". The solid block can be natural or constructed.
* The desired/kept items might not be configured correctly.

'''Symptom:''' The status '''0% V''' always appears to the right of one stop.

'''Possible Causes:'''
* The stop may not be set to take from a stockpile. Edit the Stop using {{k|Enter}} and make sure you see a message like "Take from Stockpile #1".
* The take conditions must correspond with the contents of the stockpile.
* The track stop may be set to dump. A track stop set to dump cannot be filled. You must either set the stop to a time-based departure or deconstruct the track stop and rebuild it without dumping. (Alternatively, with [[DFHack]] you can modify "Dump on arrival" to "No" using the {{key|q}} menu without rebuilding the stop.)
* Make sure the minecart itself has not been designated to be dumped (such as when using mass-dump).

'''Symptom:''' Dwarves fill the minecart properly, but will not move it thereafter.

'''Possible Causes:'''
* The minecart may contain items which are not included in its current stop's desired items. Check inside the minecart using the {{key|k}} and {{key|z}} keys and ensure that all items in the cart are desired items.
* The minecart may contain desired items in bins. Minecarts seem to have problems realizing that they are in fact full of desired items if some of those items are in bins, even if bins are also among the desired items for that stop. '''This cannot be solved by adding the appropriate bins to the stop's desired items.''' Either disallow bins in stockpiles you intend to load minecarts from, or set the departure conditions to rely only on percentage of total load rather than percentage of desired items using the advanced conditions menu ({{key|C}} key).

'''Symptom:''' Dwarves repeatedly attempt to load the minecart, but no items are ever loaded into it.

'''Possible Causes:'''
* This can be caused by using a Track Stop with autodumping enabled at a loading site. Every time a dwarf places an item into a cart resting on such a track stop, the item will be immediately dumped, causing unlimited, useless cart loading jobs. Autodumping Track Stops should never be used at a loading site.

'''Symptom:''' A dwarf picks up the minecart and carries it to its destination.
* See [[#Quirks|Quirks]]

=== Danger ===
Minecarts are not without <strike>danger</strike> [[fun]]. Although designating a track automatically sets the [[traffic]] designation to low, dwarves ''may'' still walk on them, and [[creature]]s ignore traffic designations altogether. If an unlucky dwarf or creature fails to [[dodger|dodge]] a minecart, they can be injured. Most of this danger can be avoided by setting the minecart {{k|h}}auling commands to guide instead of push or ride (dwarves guiding minecarts will ignore traffic restrictions), as well as by [[pasture|pasturing]] domestic animals and preventing the access of other creatures to the tracks. Note that removing the track doesn't reset that tile back to normal traffic priority, so you may wish to manually clean up traffic designation afterward. Also note that bridges that are used as tracks don't have their traffic priority changed automatically (since they're just normal bridges), which could cause dwarves to pathfind normally through dangerous minecart entrances in your fort's walls if you're not careful.

The only <s>fool</s>''dwarf''-proof method is to make the tracks inaccessible. There are several ways to create a track which works for minecarts but doesn't allow creature-traversal; the simplest is perhaps building a [[statue]] on the tracks. Other options include adding single-tile holes (minecarts moving at reasonable speed will jump the gap), vertical drops, minecart-triggered doors, small pools of liquid (4/7 water or 2/7 magma), and hostile creatures overlooking the tracks. For safety, both ends of the track should be isolated, making the dangerous center sections completely inaccessible (though maintenance access can be provided by a locked door).

Danger does not always involve living victims: careless route designation can also result in minecarts careening off tracks or colliding with each other. If this occurs, the [[item]]s may be scattered; this can cause even more hauling jobs than the minecart aimed to eliminate. Even <s>better</s> worse, scattered items, especially [[weapon]]s, can injure passing [[dwarf|dwarves]] or other [[creature]]s; in the words of Toady One the Great, "Accidental grapeshotting of the dining room should be possible now."

Of course, the danger of using minecarts means they can also be [[Trap_design#Minecarts|used as weapons]] by imaginative players.

== Advanced usage and automation ==
Minecart-specific effects are implemented via track stops, rollers and [[pressure plate]]s with "track" condition set. Since all three are considered [[building]]s, they can't be built on the same square (however convenient track stop + pressure plate would be) nor a simple ramp, and are removed by {{k|q}} {{k|x}}.

=== More on Track stop ===
Track stops are constructions that allow further automation of minecart systems via adjustable features such as braking by friction and automatic dumping of contents. They can be built from logs, bars and blocks through {{K|b}} {{K|C}} {{K|S}}; friction amount, dumping toggle and dumping direction must be set '''before''' construction, and these settings can be neither changed nor seen thereafter; however, track stops can be linked to [[pressure plate]]s or [[lever]]s to toggle friction and dumping On or Off (trigger state is inverted: switch On = track stop Off).

If a [[stockpile]] is placed on the tile that a track stop is set to dump to, it can act as a [[Exploit#Quantum_stockpiles|quantum stockpile]] and any items dumped from a minecart that match the storage settings of the stockpile will remain there and accumulate. Normally trackstops are built on top of existing track to operate on moving minecarts, but they can also be used without tracks to create [[Exploit#The_Minecart_Stop|automatic quantum stockpiles]] (see also [[#Step-by-step_tutorial|step-by-step tutorial]]). It is not always desirable to collect ALL of certain items into one quantum stockpile, such as when distributing a material to multiple separate industries. You can link your quantum stockpile to various other stockpiles, ensuring that your dwarves will keep them supplied as necessary. Because quantum stockpiles never fill up like regular stockpiles, it may be a good idea to add a switch to turn them off.

Items dumped from a minecart at a track stop (or dumped by any other means) into open space fall through z-levels until they land on a solid surface. Items falling onto a designated [[stockpile]] will automatically be considered part of that stockpile, even if the stockpile is set to disallow those items (they will, however, be automatically moved to a more appropriate stockpile, if available). Items falling on top of a minecart will '''not''' fall "inside" the minecart. Use with caution; dwarves have fragile skulls.{{bug|5945}}

=== Automated propulsion ===
==== Roller ====
{{Main|Roller}}

A '''roller''' is a [[power]]ed [[machine component]] for the automated propulsion of minecarts. They are built over the top of existing tracks with {{K|b|M|r}}, requiring a [[mechanic]], ''(length/4)+1'' [[mechanism]]s and a [[rope]]. Rollers may also be placed directly on ramps to help pull carts up Z levels. Rollers are very useful to maintain a cart's momentum along long routes, to get them to climb Z-levels without dwarfpower involved, and to get them to reach speeds unattainable by guiding dwarves. These devices are variable-length (1-10), variable-direction and variable-speed ([[Minecart#Numbers_behind_the_scene|see below]]), all traits that can be set at construction time; a roller uses two units of power per tile it is long.

Single-tile rollers transfer power in all four cardinal directions, while other rollers generally only transfer power perpendicular to their activity direction. Longer rollers can also transfer power along their activity direction if built in the correct order, although this can be hard to accomplish and is easily broken. Rollers cannot be powered from above.

Rollers have great acceleration and capped speed. Carts going faster than the roller are unaffected. If a cart moves across an active roller in the direction the roller works and moves slower than the roller's specified speed, the cart will be set to the roller's speed. A cart going against a roller's movement direction will be sent back the way it came (once again at the roller's speed), unless it was moving extremely fast: speed increment of 100000 allows to reverse carts from the full "highest" (50000) speed roller to full "highest" speed back, but ramps can accelerate a cart beyond this. {{cite forum|144328/5702453}}
A cart crossing over a roller perpendicular to its current movement direction will gain the roller's amount of speed in the perpendicular direction without directly changing its forward motion. Without an adjacent wall to constrict its movement, this will typically send a cart off the rails on a diagonal path, completely unable to follow any tracks until it collides with a wall or is otherwise brought to rest. However, if the roller is placed over a track turn and pushes ''from'' the direction of that turn's track, the turn affects carts ''after'' the roller, so they will be forced into the turn rather than derailed in a diagonal direction. {{cite forum|144328/5702453}}

{{diagram|spaces=yes|\
tracks: full:
║ ║
═╗═ ═╢═
║ ║

╢ : roller pushing from W to E
}}
If the roller is powered, carts from ''all'' directions (unless too fast) exit S, because speed imparted by the roller forces carts toward E and ''then'' into the turn.
If not powered, carts from W and N exit S, carts from E and S exit W. Carts above derail speed will ignore the turn, of course.

{{diagram|spaces=yes|\
║ ║
═╗═ ═╟═
║ ║

╟ : Roller pushing from E to W
}}
Carts from the E or W: exit W.
Carts from N: derailed diagonally, exit SW.
Carts from S: derailed diagonally, exit NW.

Rollers affects carts on a track - if placed on a floor or ramp without any tracks, they are ignored. Depowered rollers are also ignored, friction is determined by the tiles underneath.

Because of their one-way nature, rollers are unsuitable for most two-way minecart tracks (unless you set gears toggling roller A->B off while toggling A<-B rollers on). However, a minecart set to be ''guided'' is not affected by rollers at all{{cite forum|109460/3286235}} — this allows a one-way track to be used in both directions. In addition, unpowered rollers do not affect minecarts.

Care must be taken in [[glacier]]s and other extremely cold [[biome]]s, since rollers (and the machinery used to power them) will not operate when constructed on natural [[ice]] floors.

==== Impulse ramps ====
Carts can be given momentum without rollers or changing z-level through a phenomenon called "impulse ramps". A track ramp which is connected both to a wall and to a floor will ''always'' accelerate a cart towards the connected floor tile, no matter where the cart enters the tile from. This means carts can be accelerated as though dropping z-levels, even if the cart doesn't actually change z-level at all. If a track ramp faces three directions such as ╩, then two of those directions need to be facing walls for the cart to be accelerated towards the remaining direction.

Example of straight impulse acceleration:

{{diagram|spaces=yes|\
▒▒▒▒▒▒▒▒▒▒ ▒▒▒▒▒▒▒▒▒▒
═▲▲▲▲▲▲▲▲▲▲═ ═╚╚╚╚╚╚╚╚╚╚═
▒ : Wall
═ : Normal track
▲/╚ : N/E Track/Ramp
}}

If a cart enters from the left, it will speed up on every track/ramp and exit to the right going very very fast - more than one tile every step. If it enters from the right then it will bounce back impulsed by the ramp if it's going slow enough.

As another oddity, carts coming from ramps will in some cases "teleport" through most of the next tile. This is called the "checkpoint effect", and is explained in detail in the Physics section, below. This negates the deceleration of the next tile if it is a ramp "angled" in a different direction. You can just make an upward spiral alternating impulse ramps and regular upward ramps. It takes no power, is quick and cheap to build, requiring only channeling and track carving, and the cart goes up fast, but not so fast that it launches its contents.

Example of an impulse elevator:

{{diagram|spaces=yes|\
z +0 z +1 z +2 z +3
░░░░░ ░░░░░ ░░░░░ ░░░░░
░╔░░░ ░▼╚╗░ ░░▼▼░ ░░░░░
░╝░░░ ░▼░░░ ░░░╔░ ░░░▼░
░▼▼░░ ░░░░░ ░░░╝░ ░╚╗▼░
░░░░░ ░░░░░ ░░░░░ ░░░░░

░ : Wall
╔,╚,╗,╝ : Track/Ramp
▼ : Down Ramp (empty space)
}}

Note that this impulse elevator, due to the checkpoint effect and upward curved ramp effect, will not actually result in carts traveling straight up the ramp. They will lose speed, bounce off a ramp, then be accelerated back into the spiral after a 9-turn delay on both tiles on the floor where they are stopped. This is because the checkpoint effect allows carts to travel up the ramps in a single turn, but also prevents the impulse ramps from adding acceleration unless the cart is slowed to staying on the ramp for more than one turn. Initial acceleration will carry the cart up a variable number of floors before this effect occurs, but this bouncing back and forth will occur every 5 z-levels after the first time the cart stops. When the cart ''is'' traveling upwards, it will pass every tile at a rate of one tile per turn regardless of its actual speed, due to the checkpoint effect. In tracks with only a single cart, this is negligible, but when multiple carts are on the same track (such as when you place multiple carts on a magma cart lift) this can cause collisions which derail carts or cause other unexpected or undesired behaviors.

The following impulse ramp (while larger) should alleviate these problems by using a straight ramp to go upwards, preceded by an impulse ramp to exploit the checkpoint effect and negate up ramp costs. Corners still decelerate carts, so the cart will tend towards a velocity of 72k, which is derail speed. Derail speed breaks (see Controlling Speed, below) may be necessary at the top.

{{diagram|spaces=yes|\
z +0 z +1 z +2 z +3
░░░░░░ ░░░░░░ ░░░░░░ ░░░░░░
░░░░░░ ░╔╔═░░ ░░▼▼╗░ ░░░░░░
░║░░░░ ░▼░░░░ ░░░░╗░ ░░░░▼░
░╚░░░░ ░▼░░░░ ░░░░║░ ░░░░▼░
░╚▼▼░░ ░░░░░░ ░░░░░░ ░░═╝╝░
░░░░░░ ░░░░░░ ░░░░░░ ░░░░░░

░ : Wall
║,═,╔,╚,╗,╝ : Track/Ramp
▼ : Down Ramp (empty space)
}}

Also, if you want to have a cart following a below-derail speed, the following track works well:
{{diagram|spaces=yes|\
z +0 z +1 z +2 z +3
░░░░░ ░░░░░ ░░░░░ ░░░░░
░░░░░ ░══░░ ░▼▼║░ ░░░▼░
░║░░░ ░▼░░░ ░░░║░ ░░░▼░
░║▼▼░ ░▼░░░ ░░░░░ ░░══░
░░░░░ ░░░░░ ░░░░░ ░░░░░

░ : Wall
║,═ : Track/Ramp
▼ : Down Ramp (empty space)
}}
In this elevator, the cart collides with the walls in the corners, but then realigns on the ramp, picks up speed, checkpoints through the next ramp, and slams into the next wall. It is slower (10 ticks per floor) but produces reliable speeds, and will exit the impulse elevator at little more than push speeds.

A sort of opposite effect to impulse ramps also exists: ramps lacking the proper "up" and "down" connections are treated as flat track, even if they actually go up or down z-levels. This allows building "anti-impulse" slopes consisting entirely of ramps only connected up, which a minecart can travel up forty levels and more, needing no more than a single push.

=== Controlling traffic ===

==== Switching ====

As constructions or tile features, [[door]]s and other furniture can be built on tracks. A [[door]] or [[floodgate]] can be turned on or off by a [[lever]], effectively controlling the flow of automated minecarts. This may be <s>dangerous</s> [[fun]], however.
{{diagram|spaces=yes|\
->
A ════┤≡════ B
┤ : roller pushing to East
≡ : door
}}
The roller pushes the cart east, but until the "departure condition" is fulfilled, the door remains closed and blocks the path.

[[Bridge]]s can also act as tracks, but only if they're lowered or not retracted. This property can enable levers to turn tracks on and off. However, care should be taken to ensure that such bridges are never operated while a cart is on top of them, as the cart will be flung off the track. It's worth noting that it's often faster, and cheaper, to construct large bridges than long sections of constructed track.

A powered track switch can be constructed by building an "inverted" corner as illustrated below.
{{diagram|spaces=yes|\
B B
║ -> ║
║ ║
════╚═══ ════├════
A C A C
├ : roller pushing to West.
}}

If the cart is pushed East from the stop at 'A' while the roller is activated, it will arrive at 'B'. If the roller is not running, it will arrive at 'C'. The switch works by the roller first reversing the incoming cart's movement and the cart ''then'' following the track corner.

This switch is very reliable, reacts instantly to on/off signals, and carts of any speed can be switched by this design, although very fast carts will require rollers that are several tiles long, up to three. The requirement for power can be inconvenient or impractical. Non-powered solutions may use controlled derailment, or a connecting bridge.
{{diagram|spaces=yes|\
B ╥
║
║
╞════╝ ════╡
A D C
}}
Here the track between A and C is not continuous. The only continuous track is A->B, with a corner (not a T section). Fast moving carts will tend to derail at D and rejoin the track to C. Placing a door at D will prevent the derailment, so the cart continues to B. The door is operated by mechanisms elsewhere (typically, a lever, but some fun can be had with pressure plates).

Since it depends on derailing, this switch requires a very fast cart, faster than what can be achieved with rollers alone. To gain sufficient speed, a cart must be accelerated further, usually by descending several levels or through impulse ramps. The high speed makes the cart much more dangerous and harder to control.

If carts are moving too slowly to derail at the corner, a retractable bridge may be used as a connector between A and C.
{{diagram|spaces=yes|\
B╥
║
║
A╞════bbb════╡C
}}
The bridge must overlap the corner. Bridges behave like a track crossing, allowing carts to pass in a straight line. When retracted, the corner reappears, so the carts will continue to B. Bridges take 100 steps to react to a signal, necessitating rather long "lead times" when switching tracks via bridge.

As mentioned above, special care must be taken to make sure the bridge doesn't change state while the cart is passing over it. Retracting bridges will throw the cart, causing it to stop dead. Raising bridges can even crush the cart.

==== Controlling Speed ====


Minecarts can reach extremely high speeds, especially when descending multiple Z-levels. A minecart will derail at a track corner if its speed exceeds 0.5 t/st (tiles per step), '''unless''' the route in the direction of travel is blocked:

Will derail at > 0.5 t/st:

{{diagram|spaces=yes|\
in ══╗ -> derailing
║
out
}}

Will not derail at > 0.5 t/st:
{{diagram|spaces=yes|\
in ══╗O
║
out

O : wall/column.
}}

This behavior can be used to build a "speed limiter", that will ensure that when a minecart exits it is traveling below derail speed:
{{diagram|spaces=yes|\
░░░░ ░░░░░ ░░░░░
in ═╔═╗░ ░╔S╗░ ░╔S╗░
out ═╬═╝░ out ═╗═╝░ out ═╗═╝░
░╚S╝░ ░╚═╝═ in ░╚S╝░
░░░░░ ░░░░ ║░░░
in
░ : wall
S : Track Stop (High Friction or lower)
}}
If the minecart is traveling below derailment speed, it will not be affected; if above, will be slowed down and checked again. Granted, you could do the same just with track turns, but it may take a lot of turns and time.

Since all the derailings, bounces and ramps can impart a sideway component of speed small enough to start visible drift many tiles away (say, [[Fun|in the middle of a bridge]]), track turns have one more use: forcing the carts to move strictly along the grid directions. Carts passing a turn below derailing speed convert one component of velocity into another, thus eliminating the drift.

=== Loading liquids ===
[[Water]] and [[magma]] can also be loaded into minecarts by submerging them to a depth of at least 6/7 while standing still or moving at speeds of at most 10000. Loading fluids onto minecarts can be difficult because the added friction provided by fluids can stop a cart in a submerged tile. Curiously, filling a minecart with magma does not injure a dwarf ''riding'' it. A minecart will hold enough fluid to increase the depth of a single tile by 2. This amount is listed as 833 units, which weigh 459Γ (water) or 999Γ (magma). An iron or steel cart filled with magma weighs 1313Γ, while an adamantine cart filled with magma weighs 1007Γ. Since you need a minecart above the liquid's level, possible arrangements may include pressure-activated sluices, rollers (with magma-safe chains for magma), pouring from above to "submerge" it briefly on the same level and drain excess away (dig deeper and leave a vaporizer, though if you could have power for rollers, may as well use a pump) and exploits with ramps (not necessarily impulse ramps, "same height" passing dip does it).
The liquids can be dumped by a constructed track stop.

== Quirks ==
This little quirk concerns dwarf-managed minecarts. If a track which was previously open becomes blocked (ex. flipping a switch connected to a floodgate you've built on the track to raise it) and the conditions for departure are met, instead of refusing to ride/guide the minecart or ride/guide it until it reaches the obstacle, the dwarf will pick up the minecart off the tracks and haul it to its scheduled destination on foot. If the distance is long enough and the weight of the cart heavy enough (due to being filled with heavy items such as stones), the dwarf may drop the cart because of fatigue/hunger/thirst before reaching the destination. This will cancel that vehicle setting job and make another dwarf come by and attempt to haul the cart to the nearest appropriate stockpile where another dwarf will pick up the cart and attempt to haul it to its initial stop. If the stockpile is far enough from initial stop, this second dwarf who is attempting to place the minecart on its tracks may also drop the minecart out of fatigue/hunger/thirst creating a loop that will go on until a dwarf with enough endurance manages to place the minecart where it belongs.

In fact, it seems dwarves are more than happy to attempt to carry a minecart from one stop to another even if just waiting until the track is open again would be the more sane option.

Dwarves will also carry a minecart to its next stop if the direction specified is incorrect (or invalid). This can often occur when using the default departure settings and forgetting to set the direction of each condition.

Dwarves can admire buildings while riding mine carts. Dwarves will not fall asleep during a ride (at least not from being drowsy). If riding on a continuous powered track loop, the dwarf will die of dehydration/starvation as they can not jump off to get sustenance{{cite forum|109460/3377228}}. Dwarves riding in submerged minecarts will gain experience in [[swimming]].{{cite forum|129889}}

Tracks block wagon access to trade depots, unless they're on a ramp. [[Bridge]]s can also be used, as they function as tracks but do not block wagons.

== Physics ==


Minecart physics depend greatly on the departure mode set in the route stop conditions.

When set to "Push" or "Ride", minecarts will move according to the regular laws of momentum, gaining speed when going downhill, losing it slowly due to friction when on a flat plane, and more quickly when going uphill. In these modes, minecarts will move in a straight line until they either are brought to a stop by friction or an obstacle, or until they encounter a turn. A minecart will roll straight past "blocked" ends of T-junctions or track ends, they have no power to restrict a cart's movement. The cart's behavior is largely independent of the weight of its contents (including fluids and dwarves): heavily loaded carts gain more momentum when accelerating, but this only plays a role in collisions: a heavy cart gains just as much speed and is as easy to stop as a light one. In either case, dwarves can not push nor ride an unpowered cart up a ramp, bouncing back the direction it came. At best, this is a waste of time; at worst, it will give your cart-pushing dwarf a [[fun|fun surprise]]. To solve this, the player can either use Rollers (see below) or set the cart to be Guided.

The difference between "Push" and "Ride" is whether the dwarf will go along with the cart or not.
{{DFtext|Push}}: the dwarf will give the cart an initial push, not enough to go up a ramp, but enough to go some way along flat track, and the dwarf will remain at the first stop, ready for a new job.
{{DFtext|Ride}}: the dwarf will give the cart the same initial push and then hop aboard the cart riding with it to the next stop.
{{DFtext|Guide}}: minecarts seem to ignore all laws of physics. That is:
*Ignore the weight of any and all items inside. Therefore:
**Move at the speed of the dwarf that is guiding them. It is thus recommended to pick the most [[attribute#Agility|agile]] of your dwarves for cart-guiding tasks.
*Ignore working rollers.
*Will ''not'' collide with other guided carts even when a full frontal collision would be expected.
*Will go up ramps like nobody's business.
This is therefore the recommended method of transport for simple non-powered rail systems, despite it diverting a dwarf from other, potentially more important tasks.

Some samples with behavior:
{{diagram|spaces=yes|\
A <-> B A <-> C A <-> B
B B B
║ ║ ║
A══╝ A══╩══C A══╬╗
You can only go A->B ╚╝
Works when the cart Works
is in Guide mode.
}}
In the second example above, a cart "pushed" from B will go over the junction and roll off into the unknown south.

=== Track Direction Irrelevance ===
Carts that are traveling independently, (that is, not guided,) only care that tracks ''are'' on the tile, not which direction the tracks actually move. Tracks respect only curves (with two exits) and ramps.

This means, for example, that the following tracks, when a (non-guided) cart travels from West-to-East, are functionally identical in effect:

{{diagram|spaces=yes|\
A════════════B A╬║╚╔╣╩╦╠╥╨╞╡B
}}

This is because so far as the cart is concerned, only ramps and curves with two exits where the exit in the path they are traveling matters.

Hence, if a minecart encounters the end of the track or a T junction with no "exit" in its movement direction, it will simply leave the track and continue on its course in a straight line until it encounters an obstacle, slows to a stop, or encounters another track even if the tile at which it joins the new track instantly sends it around a corner.

In fact, a "║", a "╦", a "╬", and a "╥" are ''only different in appearance'', and are ignored by the cart, which will continue in its current direction, regardless of the track.

Carts only check for curves when they are halfway through a tile. When they get there, they look to see if their path has no exit. (That is, if it is traveling East, it checks if there is an East exit.) If there is, it ignores all other track directions, and keeps traveling. If there is not, it checks to see if there are only two exits to the track, and if one of those directions was the direction it "came from". (That is, if traveling from the East, it checks if there is a valid exit to the West, and if so, if there is either a North exit or a South exit.) If there is not, it ignores the track anyway, and keeps on traveling as though it were still on track. If there is, it will subtract 1000 from the velocity of the cart, and redirect all forward velocity to the direction of the curve. This change in the direction of velocity ''overwrites'' any "diagonal" velocity, which can prevent diagonal velocity derailments, but any perpendicular velocity is not preserved, and is instead discarded.

=== Valid and Invalid Ramps ===
Ramps are functionally defined for cart purposes as being a tile which exerts an acceleration force upon its "downward slope", and which allows connection to tracks a z-level above or below. This downward slope requires a cart to have one ''and exactly one'' carved exit to the tile that is the "bottom" of the ramp. Ramps accelerate carts in this "downward" direction (possibly leading to diagonal movement, below), and the deceleration of an "uphill" ramp is actually just the acceleration being applied against the direction of a cart's movement.

This is where players can find an exploit in the behavior of ramps - if there are ''two'' "downhill" exits to a ramp (such as a "T junction" on a ramp where only one exit faces a wall), then the ramp provides no acceleration ''or'' deceleration, allowing carts to travel up ramps without any loss of momentum except for the standard "flat track" deceleration, because as far as the cart is concerned, the track ''is'' flat. (A T junction is also not a curve, so the track is considered flat and straight no matter what direction the cart is traveling.)

Similar effects can be achieved when there are ''no'' "downhill" exits to a ramp. This may be the case if you have, for example, an East-West track with a one-tile channel with a ramp in it. The cart will travel through the "dip" with no change in velocity. It can also be the case if you abuse the Track Direction Irrelevance, above, and set only exits ''up'' the ramp, and none leading ''down'' the ramp. For example, if a cart is traveling from West to East up a slope, only carving East exits on each tile of ramp will make the cart travel up the ramp, and then recognize the tile it is on as being a "flat" tile, thus ignoring any deceleration from traveling uphill.

Note that this effect only reliably occurs at below-derail speeds as the cart will treat the ramp as an invitation for a ramp jump otherwise. (This almost always results in a collision with a wall that will stop forward progress.)

=== Falling ===
When falling, a minecart appears to cause no damage upon collision, possibly to allow cart "stacking" across Z-levels.{{cite devlog|2012|04|06}} A dwarf riding in a minecart that is dropped multiple z-levels suffers normal fall damage. Minecarts can fall through up/down stairs.

While airborne, carts do not feel the effects of friction in any horizontal direction, and will continue until they strike an obstacle. Carts that land on tracks instantly re-rail themselves regardless of track directionality.

Falling carts accelerate similarly to the way that a ramp will accelerate a cart in a special z-only velocity that only applies to airborne carts. (Actually, acceleration due to gravity in freefall seems curiously slightly ''slower'' than ramp acceleration.) Ramp acceleration, while it logically should be partially z-directional, is only recorded as x- or y-directional, and there is no translation of z-directional velocity upon landing. Landing carts zero out their vertical velocity upon landing, even when landing on ramps, although carts that had horizontal momentum while falling preserve it.

This means a cart falling (from a hatch, thus with no horizontal speed) onto a track ramp is accelerated as if starting from the middle of the ramp - i.e. to the same speed, no matter how many Z-levels it was dropped, vertical velocity is negated. {{cite forum|144328/5701211}}

Carts falling onto a floor can, however, cause damage to creatures ''one tile below the floor''. This can be used in an [[exploit]] called a "thumper", where carts are caused to repeatedly fall on a floor above an entrance to the fort, inflicting significant damage (as though it were a collision) on those below the cart.

=== Cart Jumps ===
Carts that cross off of "up" ramps relative to their current direction of travel, which do not have a ceiling above them, are traveling above derail speed, and do not have valid ramp track before them can translate a portion of their horizontal velocity into vertical velocity, causing a cart to be projected into the air until vertical velocity is negated and overcome by the gravitational acceleration. Because downwards acceleration is applied per-tick, this creates a reasonable facsimile of the parabolic motion of an actual object rolled up a ramp and launched with significant speed.

{{diagram|spaces=yes|\
z0 z0 hiding ramps z+1 A z+1 B (hidden ramp)
▒▒▒▒▒▒▒▒▒▒▒▒ ▒▒▒▒▒▒▒▒▒▒▒▒ ▒▒▒▒▒▒▒▒▒▒▒▒ ▒▒▒▒▒▒▒▒▒▒▒▒
═▲▲▲▲▲══▲▒▲═ ═╚╚╚╚╚═══▒══ ▼▼▼▼▼ ▼═▼ ▼▼▼▼▼ ▼╚▼
▒ : Wall
═ : track
▲ : Ramp
}}
In this diagram, if there is no ceiling above it, the track in z+1 A will launch its carts airborne when they travel across the ramp. z+1 B (with a ramp on the tile on the hill) will not launch the cart. The cart would also not be launched with ''any'' valid ramp, even if it does not travel in an appropriate direction, such as North/South (which the cart will ignore, as it is not a curve, anyway, although it may produce acceleration that may cause diagonal movement.)

Carts that are traveling at derail velocity will also start "jumping" from the track if it hits an un-tracked tile, flying over and ignoring any tracks until it is ready to land. Carts that land upon tracked tiles re-rail themselves, and clever designers use this feature to jump over curved track sections in one direction or another. (Retracting bridges over untracked tiles can cause jumps or not cause jumps depending upon the status of the bridge.) Minecart speed must be carefully regulated to ensure reliability of jump length.

Hitting untracked tiles at around 70k velocity creates a vertical component to acceleration that allows for jumps of around 6 (horizontal) tiles that do not actually leave the z-level the cart is on, but which do apply z-direction velocity on the cart, as per falling.

Carts that approach a downward slope at a high enough velocity will also make a jump, (or rather, ignore the ramp and fly forwards) but will not do so if the Checkpoint Effect (below) is exploited through an impulse ramp before the actual downhill as the impulse ramp "tricks" the cart into thinking it has already started going downhill. The cart will also not fly off the ramp if there is a wall and ceiling preventing any motion but going down the ramp.

=== Skipping ===
If a minecart is moving fast enough, it can skip over [[water]] or [[magma]], making splashes of [[mist]] (or [[magma mist]]) as it attempts to move on them horizontally. This horizontal movement is independent of the minecart and its content's [[weight]].

Skipping causes significant friction on the cart, and even a cart going at max speed from ramps can only make about 50 tiles without requiring re-acceleration. (Carts that decelerate enough that they do not trigger the skipping effect will, of course, sink.)

=== Corner Ramp Derail ===

Corners on upward ramps can cause diagonal movement, forcing a derail even if the cart has a wall next to it, which will force a stop when it touches a wall that forces dwarves to manually reset the cart.

This is caused by the fact that a cart, after turning the bend in the track halfway through the length of the tile, will still "accelerate down", which is now perpendicular to the movement of the cart, causing acceleration to occur in two directions. (Down corner ramps do not have this problem, as when they pass the halfway point, all perpendicular motion is added to forward motion, and after that curve, all downward acceleration is in the forward direction.)

There are two fixes to this problem. One is to simply not put corners on up ramps. The other is to take advantage of the Checkpoint Effect, below, by making a ramp (possibly including an impulse ramp) one tile in front of the ramp to make it skip through most of the tile before sideways momentum can be built.

=== Checkpoint Effect ===
The checkpoint effect, [http://www.bay12forums.com/smf/index.php?topic=144328.0 explained in depth by Larix], is an odd and highly exploitable feature of ramps where minecarts "teleport" through the next tile of track, ignoring nearly all minecart physics (except that they stop at all walls or other obstacles and only respect curves with no backing wall and invalid ramps if they are below derail speed) and passing through that tile in just a single tick, and into the next tile at the halfway point.

This effect occurs when a cart leaves a downward ramp for any other direction of tile. (This includes ramps which accelerate in different directions, even a ramp which goes from accelerating East to accelerating North due to a bend in a chain of standard down ramps in a curve.) This allows, for example, two valid straight ramps directly next to one another with a cart dropped onto one or the other with no momentum to have the cart pick up acceleration going "down" the ramp as normal, but then flying up through the "up" ramp it travels into with no loss of momentum, as though it had come from an impulse ramp. If the two ramps had at least one space of distance between them, and then a cart were dropped in, the cart would instead "rock" back and forth between the two ramps.

This seems to be because ramps have a slightly longer length than regular tiles - 144,000, rather than 100,000 distance. When this "snaps back" after a ramp, it seems to project the cart suddenly further along the track, making it jump a tile ahead even when otherwise moving at relatively low speeds.

This [[bug]] is the cause of a ''wide array'' of unexpected behavior among people who do not take this bug into account. It causes derailments or failure to climb up seemingly valid impulse elevators. In general, it makes a system that behaves extremely counter-intuitively, and operates ''any time a cart encounters a valid ramp''. At the same time, when its effect is accounted for, it is highly exploitable: It causes "perpetual motion devices" using no power when two opposing ramps are placed next to one another, since the "uphill" effect of the opposing ramp is ignored, preventing deceleration.

Another useful thing to note about this exploit is that carts traveling at no less than 72,000 or so speed (enough to travel half a ramp tile in a single tick) can travel through every tile in just one tick at no change in velocity as long as the tiles alternate between impulse ramp or actual down ramp and any other tile type. The cart checkpoints through the non-down-ramp tiles, and can pass through the (impulse) down ramp tiles in a single tick, before they can actually start gaining momentum.

{{diagram|spaces=yes|\
▒▒▒▒▒▒▒▒▒▒ ▒▒▒▒▒▒▒▒▒▒
═▲═▲═▲═▲═▲═ ═╚═╚═╚═╚═╚═
▒ : Wall
═ : Normal track
▲/╚ : N/E Track/Ramp
}}

If the cart enters from the West at less than 72,000 speed, some of those ramps will cause Eastward acceleration.

This means that an impulse ramp not contiguous to other impulse ramps has a top speed of around 75k:

{{diagram|spaces=yes|\
▒▒▒▒▒ ▒▒▒▒▒
▒╔═╗▒ ▒╔═╗▒
▒╚▲╝▒ ▒╚╗╝▒
▒▒▒▒▒ ▒▒▒▒▒
}}
This setup makes a cart that travels clockwise at a speed that fluctuates around 75k velocity. If the cart has more than 72k velocity, it fails to accelerate in the ramp, as it leaves the ramp in a single turn due to checkpointing to the halfway point. After that, the curves sap 1k velocity, and every tick saps 10 velocity.

Two contiguous impulse ramps with a same-facing "downwards slope", however, do not suffer the checkpoint effect in the second tile, giving functionally triple the space to accelerate. This means it will add velocity (at the standard rate of 4.9k per tick) up to a maximum speed of 216k.
{{diagram|spaces=yes|\
▒▒▒▒▒▒ ▒▒▒▒▒▒
▒╔══╗▒ ▒╔══╗▒
▒╚▲▲╝▒ ▒╚╗╗╝▒
▒▒▒▒▒▒ ▒▒▒▒▒▒
}}
This example results in a cart moving three times as fast as the previous cart.

Three successive ramps results in the highest attainable speeds.

In practical terms, this means that only consecutive ramps should be used for high acceleration, but singleton ramps can be used to have speeds that are somewhat regulated.

=== Stacking ===
If a minecart lands on top of another minecart, they may form a stack, with the upper cart on the z-level above the lower. Subsequent carts do not form a stack, but rather quantum stockpile in the same space. This behaviour is useful for [[megaprojects]] and [[trap design]] with minecarts as the weaponry. Moderation should still be exercised: carts take longer to fall into a "stacking" tile already occupied by other carts and will spend that time "hanging" in the air above the stack. This can lead to following carts striking them, which can cause all kinds of malfunctions. The extra time is two game steps for every cart already in the stack, which doesn't hurt stacks of ten carts very much but makes stacks of 100+ rather impractical.

These minecarts on the upper level generally need to be struck with another minecart to move out, or have their support removed. The latter option is safest done by shooting it away with another minecart, manual removal of a stack-supporting cart typically causes the next cart from the stack to [[fun|fall on top]] of the hauler.

=== Perfectly Elastic Collisions ===
Minecart collisions are perfectly elastic, meaning that not only do minecarts not take damage, but that two carts that are rolling which have frontal collisions of near-similar speed, and where one cart is no more than twice the mass of the other cart, will result in a billiard-ball-like effect of the lighter cart bouncing off the heavier cart with a proportional speed increase dependent upon the relative momentum behind the heavier cart.

Using this trick with carts already at the 270,000 maximum speed from ramps can result in "supersonic" carts traveling at speeds in the millions (travelling a dozen tiles per tick), but where they are suddenly subject to 10,000 units of "terminal velocity" friction per tick. [http://www.bay12forums.com/smf/index.php?topic=137557.0 Thread with SCIENCE here].

While hypothetically capable of launching a minecart into orbit when used in conjunction with a ramp, no cargo can be contained in the launched cart, as the collisions will force ejections of the cargo. Your "unwilling volunteer" [[goblin]] space pioneers will simply become paste underneath the wheels of an extreme high-speed cart.

=== Numbers behind the scene ===

According to early research by '''expwnent'''{{cite forum|112831/3536975}}:

The minecart has a variable for speed. Speed is measured in tiles/100000 ticks, so a speed of one hundred thousand means one tile per tick. By going down a large number of ramps, a maximum speed of 270,000 can be reached, which presents the limit for most practical applications. Short bursts of (much) higher speeds are possible through carefully planned collisions of high-speed carts {{cite forum|137557/5145499}}.

Every tick the cart accumulates distance units, as well as slows down depending on current tile (speed is reduced by "friction" of the tile). The cart will move to the next tile the tick before accumulating 100000 distance units, (or several tiles in case of great speed), then the leftover distance units are added to the default 100000 distance u. of the next tile. Since most deceleration and acceleration is applied per step, with the notable exception of corners, a cart going at twice the speed of another one can cover about four times the distance in a straight line, but only twice the distance along a winding track with very many corners.

A push will teleport a cart to the beginning of the next tile (NOT the middle!) in one tick with 19990 speed (10 speed is lost due to track friction), while a roller will give a cart the roller's set speed, and it will start to accumulate regular track friction past the middle of the roller tile. Some track features will affect a minecart when it is past the middle of the previous tile: entering a ramp or a hole/drop will happen when the cart has left the middle of the previous tile, and the ramp will gain additional distance unit depending on the leftover units from the previous tile. When a cart leaves a ramp it will emerge after one tick in the middle of the next regular tile, so its entry coordinate is "50000-speed+friction". Rollers also affect the speed of minecart from the middle of the previous tile.

Friction of tiles:
{| class="wikitable"
|-
! Tile
! Friction
! Comment
|-
| Tracks
| 10
|-
| Ground/Floor
| 200
|-
| Unusable ramp
| 10
|-
| Upwards ramp
| 4910 (10+4900)
|-
| Downwards ramp
| -4890 (10-4900)
|-
| Roller
| ±100000 (but capped by the set speed)
|-
| Corner track
| 10
| Speed reduced by 1000 upon leaving the corner tile
|-
| Track stop (highest)
| 50000
|-
| Track stop (high)
| 10000
|-
| Track stop (medium)
| 500
|-
| Track stop (low)
| 50
|-
| Track stop (lowest)
| 10
|-
| Water 1-6
| Additional (WaterLevel - 1) * 100
| rowspan="2" | [[#Skipping|See Skipping]]
|-
| Magma 1-6
| Additional (WaterLevel - 1) * 500
|-
| Empty space
| 0
|}

Water of depth 7/7 provides a friction of about 10000 per step, as does maximum-depth magma. This higher friction may not apply to very slow-moving carts.

Impulse sources:
{| class="wikitable"
|-
! Feature
! Speed
|-
| Push
| 20000
|-
| Roller lowest
| 10000
|-
| Roller low
| 20000
|-
| Roller medium
| 30000
|-
| Roller high
| 40000
|-
| Roller Highest
| 50000
|-
|}

== Non-standard uses ==
Minecarts include some interesting characteristics that have motivated uses beyond hauling. They can be useful for creating fully-automated [[exploit|quantum stockpiles]] and [[garbage disposal]]s. Storing perishable goods (meat, meals, etc.) inside a minecart appears to guard against rot and vermin.
Minecarts can be [[Trap_design#Minecarts|used as weapons]], or as (hopefully non-fatal) triggers to restart stalled [[healthcare]]. They can also be used to time/control game events, either using a basic [[repeater]] or much more advanced [[minecart logic]].
Minecarts trigger [[pressure plate]]s, which means a trap can be designed to trigger when a thief attempts to steal a minecart.
A pressure plate can be used as automatic and more precise custom "launch when full enough" system - as long as weight of your minecarts stays the same. You cannot build a hatch or roller on the same tile, so launch by bumping with another cart. {{cite forum|15096/4580050}}
Dwarves riding minecarts can attack enemies within reach (which goes back to dev log). This applies to shooting, and they actually can hit targets while riding by.{{cite forum|109460/5266119}} Whether a minecart protects the rider and how it interacts with dodging is not known yet. Minecart riders can also [[Swimming#Minecart_training|train swimming]] and [[Megaprojects#Surveillance_Track|detect ambushers]].

== Adventure mode ==
In addition to being used for hauling, minecarts can also be ridden in [[adventure mode]]. (Adapted from forum thread {{cite forum|122903/4258212}})

# If the minecart is in your inventory, drop it. If it is already on the ground, proceed to step 2.
# Press {{k|u}} when you are 1 tile away from the minecart (or standing on the same tile as the minecart).
# You will be presented with the following options:
[[File:minecart adventure mode menu.png|left]]
{{clear}}
* If you {{DFtext|Push}} the minecart, it will move a few tiles in the direction you chose. Physics comes into play here, so it will gain/lose speed depending on the usual factors.
* If you {{DFtext|Ride}} the minecart, you will hop into the minecart, even if you were a tile away, and it will move in the chosen direction with you in it. It will gain/lose speed depending on the usual factors. Whilst the minecart is in motion, you should press {{k|.}} to skip your turn; if you attempt to move whilst the minecart is still in motion, the laws of physics come into play, and you will take [[wound|damage]]. Alternatively, you can push the minecart whilst it's still in motion (although it's unclear how one can bend [[physics]] so as to push a moving minecart whilst inside the minecart). If you push it in the same direction you are already travelling in, you will greatly increase the minecart's velocity. You can also push it in different directions, and this will cause it to gradually change direction-the amount of pushes this requires depends on the minecart's velocity. Once the minecart has stopped moving, you may move out of it safely, or you may want to give it another push. Note that if you push a minecart right after having ridden it (still on the same tile as the minecart), it will act as though you chose to ''ride'' it.

If you want to test this out without creating an adventurer, the [[object testing arena]] allows you to spawn minecarts ({{k|k}}-{{k|c}}-{{k|n}})

== Forging and Melting ==
* Metal minecarts cost '''two''' [[metal]] bars to forge, or '''six''' [[adamantine]] wafers.
* When a non-adamantine metal minecart is melted down, it will return '''1.8''' metal bars, for an '''efficiency of 90%'''.
* When an adamantine minecart is melted down, it will produce '''1.8''' wafers, for an '''efficiency of 30%'''.

== See also ==
* [http://www.bay12forums.com/smf/index.php?topic=109460.0 The "How Does Minecart" Thread] by '''Girlinhat''' et al.
* [http://www.bay12forums.com/smf/index.php?topic=112831.0 SCIENCE: Quantifying minecart physics] by '''Snaake''' et al.
* [http://www.bay12forums.com/smf/index.php?topic=129676.0 How to build a Multi-cart Ore to Magma Minecart Project without needing power] by '''WanderingKid'''.
* [http://www.bay12forums.com/smf/index.php?topic=144328.0 My very own Minecart Education Thread. Ten Lessons, now complete.] by '''Larix'''.

== Bugs ==
*A dwarf will drop her [[child|baby]], if she has one, when boarding a minecart set to be ridden.
*Dwarves have no concept of traffic safety and will walk into busy minecart lines to retrieve objects, often with deadly consequences. This is especially problematic in [[Swimming#Minecart_training|clever applications]] depending on dwarves riding the carts very frequently, because they have a bad habit of dumping their worn clothes on the tracks after a minecart ride. Adding an automatically-operated [[hatch cover]] at the end of such a ride can help prevent [[unfortunate accident]]s.
*Dwarves cannot guide a minecart through an unlocked door unless another dwarf opens the door.{{bug|6056}}
*It is possible for a creature and minecart moving towards each other to pass without collision if they exchange tiles in the same tick.
*After a minecart ride, a dwarf will sometimes haul the minecart to a storage stockpile, leaving another dwarf to haul the vehicle back to the route.
*Minecarts falling onto a floor injure creatures in the tile below the floor.{{bug|6068}}
*A minecart's initial velocity is not affected by weight, when pushed or launched from rollers.{{bug|6296}}
*Removing a stop that has a vehicle waiting on it may cause the game to crash.{{bug|5980}}

{{Category|Fortress mode}}
{{Category|Interface}}

[[ru:Minecart]]

Minecart

2015-06-18T21:45:06Z

NW Kohaku: grammar fixes, more specific language

{{Quality|Masterwork|08:15, 19 May 2015 (UTC)}}
{{av}}
A '''minecart''' is a [[tool]] intended for [[hauling]], introduced in version 0.34.08. It can be made of [[wood]] at a [[carpenter's workshop]] or [[metal]] at a [[metalsmith's forge]] (using the [[Metal crafter|metalcrafting]] labor.) Minecarts store up to five times as many items as [[wheelbarrow]]s and are quite a bit faster than dwarves hauling objects by hand, but have the disadvantages of requiring a dedicated track network, a complex route planning phase, and the possibility of dwarves [[Fun|blundering into the path of carts filled with lead ore]]. Tracks may be carved into stone, or [[Construction|constructed]]; the latter allows above-ground routes, but these are more difficult to set up due to their additional [[building material|material requirements]].

Just like wheelbarrows, minecarts are considered [[item]]s and are stored in a [[furniture]] [[stockpile]]. Despite their five-times-greater capacity, they are only 33% larger than wheelbarrows and are identical in base [[item value|value]] when made from the same [[material]] (the value may differ due to the [[item quality]]). [[thief|Thieves]] or even mischievous animals can steal minecarts, even when they are moving on a track{{cite forum|109460/3289070}}. However, minecarts moving fast enough or being ridden cannot be stolen.

Although most of the utility of minecarts is in [[fortress mode]], an [[adventure mode|adventurer]] can also ride in a minecart. Adventurers can also pick up and relocate minecarts.

The invention of minecarts revolutionized the [[minecart logic|Science of Dwarfputing]] by enabling smaller, faster logic systems to be built.

== Basic Minecart Usage ==
Minecarts can be used to swiftly transport dwarves, [[flow|fluids]], and/or large amounts of items, but before you have a functional minecart there are several preconditions that need to be met. First of all you need an actual minecart, constructed either in a [[carpenter's workshop]] or [[metalsmith's forge]]. For the minecart to be able to move you also need to carve (with {{k|d}} {{k|T}}) or construct (with {{k|b}} {{k|C}} {{k|T}}) a track, which could be as simple as a straight line. Finally you need to construct stops on your track (with {{k|b}} {{k|C}} {{k|S}}) where the minecart will start and stop.

After you have created the stops and assigned a cart to the track, you must create logic routes connecting several stops and designate starting conditions for each stop. This is done with the {{k|h}}auling key. The most basic conditions are how the cart's movement is initiated and in which direction the cart should start moving. Carts can be either be Pushed (a dwarf stands at a stop and gives the cart a single push) or Guided (a dwarf continually pushes the cart forward, guiding it along the track). The [[hauling]] [[labor]] required for pushing and guiding carts is called "Push/Haul Vehicles" and is turned on by default.

To control which items to transport you can add conditions specifying: (1) which kind of items to be loaded, and unloaded, (2) stockpile links to define which stockpile(s) the items should be un/loaded to and from.

===Capacity and weights ===
Minecarts have five times the [[Weight|capacity]] of [[wheelbarrow]]s.

'''Examples of the capacity of one cart'''
{| class="wikitable"
|-
! Item
! Amount
|-
| [[stone]]
| 5
|-
| [[wood|log]]
| 10
|-
| [[block]]/[[bar]]
| 83
|-
| [[Kitchen|prepared meals]]
| 500
|-
| [[Trap_component#Spiked_ball|spiked balls]]
| 500
|-
| [[Weapon#Native_weapons|mace]]
| 625
|-
| [[Weapon#Native_weapons|spears]]
| 1250
|-
| [[cloth]]
| 2500
|}

The weight of the loaded minecart does not affect the initial velocity received from pushing or launching from a roller. However, the load of a minecart ''does'' affect whether a [[pressure plate]] triggers or not, based on the pressure plate's setting.

'''Weights of different carts'''

{| class="wikitable"
|-
! Type of cart
! Empty cart
! Fully loaded (items)
|-
| oaken minecart
| 28Γ
| 378Γ (10 oak logs)
|-
| platinum minecart
| 856Γ
| 10482Γ (83 gold bars)
|}

The weight of a minecart is one twenty-fifth (1/25) the [[density]] of its material in Urists. Because pressure plates can be set to trigger at intervals of 50 Urists, minecarts with weights just under a multiple of 50 are ideal for switching based on whether they're full or empty. The best minecart materials for full/empty switching are as follows:

{| class="wikitable sortable"
|-
! Material !! Minecart weight !! Content weight required to trigger !! Banana roasts required to trigger (for scale)
|-
| [[Bismuth]] (moods only) || 391 || 9 || 15
|-
| [[Brass]] || 342 || 8 || 14
|-
| [[Electrum]] || 596 || 4 || 7
|-
| [[Fine pewter]] || 291 || 9 || 15
|-
| [[Glumprong]] || 48 || 2 || 4
|-
| [[Lay pewter]] || 291 || 9 || 15
|-
| [[Nickel silver]] || 346 || 4 || 7
|-
| [[Tin]] || 291 || 9 || 15
|-
| [[Trifle pewter]] || 291 || 9 || 15
|}

=== Creating tracks ===
Minecart tracks are made up of contiguous track, tracked ramp, or bridge tiles. Track tiles and tracked ramp tiles have a direction or series of directions associated with them. These directions dictate which directions a minecart on a given tile may move from that tile. For example, a Track NE (northeast) tile allows a minecart on it to move either north or east from its present position. Therefore, if you want your minecart to move east along a straight piece of track, then return west using that same track, you would need to use EW tracks so that the cart could travel east initially, then return west over the same track. Excluding designs in which the cart will "jump" tracks via a drop or other ramp, tracks must be valid end to end to work for most looped or straight-track applications. A single east only track tile in your line of east-west tracks will cause any route using the track to fail the moment it tries to go the wrong way over that tile. Minecart tracks can be built in two ways: Engraved/carved or constructed. A given minecart track need not use engraved or constructed elements exclusively, as the two methods can be used interchangeably depending on the needs of a given section of track. The way the tracks are built is slightly different between the two, as explained below.

====Simple tracks====

'''Carved'''

A single-tile wide strip of natural stone can be designated to be [[Engraver|carved]] (with {{K|d}} {{k|T}}), which will create a straight two-way track. The creation of corners, crossings, and T-junctions is as simple as designating another strip of track that overlaps an existent or newly designated track. Engraved tracks are removed by [[smoothing]] the rock they're on, which results in a smooth floor (that can be re-engraved if necessary), or by building a [[floor]] on top and subsequently removing it. Dwarves can carve corner tracks in one pass by designating the track carving twice and canceling unwanted carvings (with {{K|d}} {{K|x}}). Tracks can be engraved in any natural floor tile, rough, smooth and even over engravings, providing an easy method to remove low-quality or undesired floor engravings. Once a track has been engraved, it's important to check the track directions for each tile in the route carefully to make sure no mistakes were made by yourself or the game's track engraving logic.

'''Constructed'''

Tracks can also be built as regular [[construction]]s (through {{K|b}} {{K|C}} {{K|T}}). This method is resource-expensive, since each track tile requires one stone, [[bar]], or [[block]] for construction, and time-consuming, since you can't designate strips longer than 10 tiles at a time. Corners, crossings, T-junctions, and ramps also have to be designated individually. However, it is usually the only way to build tracks above ground or on soil (barring the [[Obsidian farming|creation of obsidian]]). Constructed tracks are designated for removal like any regular construction; be aware that removing track ramps built on top of natural ones will also remove the original ramp, leaving a flat floor.

====Ramps====

'''Carved'''

The carving of natural ramps is a little more confusing: to carve a two-way track on a ramp (natural only, does not work on constructed ramps), you must designate the track '''starting on the ramp and one square beyond''' in the direction you want the track to go. For the side of the ramp square you want to head upward, there '''must''' be either a natural or constructed wall in the square next to it, otherwise the game assumes you are trying to carve it on the same level -- this can result in the track being carved underneath a door or other object. If you have accidentally done this, you can correct it by smoothing the ramp and constructing a single square of wall next to it, then re-carving the ramp correctly. (However, the wall must stay there permanently; removing it will disconnect the track.)

'''Constructed'''

When constructing track ramps, the stated direction should be the same as the connected tracks. For example, a track going up from West to East would require, starting from the West, a Track (EW), a Track/Ramp (EW) and a Wall behind the ramp, underneath the section of track above it. Incorrectly placed ramps result in minecarts ignoring the ramp and crashing into the supporting wall. They will not, however, display as unusable as when the supporting wall is missing.

'''Examples of ramps'''

A simple ramp would look like this:
{{diagram|spaces=yes|\
z +0 z +1
░░░░ ░░░░
═▲o ░▼═
░░░░ ░░░░
o : wall
}}

Carving track corners into ramps is rather unintuitive and complicated. Since engraving tracks always requires two tiles to connect in a straight line as input, you have to give two separate designations for a single job: a track bit from the ramp tile to the "below" direction and another one to the wall of the "upward" direction. If you wanted to change direction on a ramp from east to north:
{{diagram|spaces=yes|\
z +0 z +1
░░░░░ ░░░░░
░░░░░ ══╗░░
=▲░░ ░░▼░░
░░░░░ ░░░░░
}}
you would need to connect the ramp on z +0 both to the west and to the north by issuing two "carve track" commands, one selecting the ramp and the track tile to the west, and another connecting the ramp tile with the wall to the north. An engraver would then carve a NW track corner into the ramp, allowing carts to pass the corner correctly both going up and down. Such track corners are perfectly serviceable for guided carts, but moving down a route of several of them by pushed or ridden cart is problematic - ramps on corners behave very counter-intuitively, resulting in loss of speed when going down and diagonal movement when going up.

Moving to and from ramps (or between ramps "pointing" in different directions0 causes some non-trivial adjustments to speed and even moving along the tiles at a fixed speed ''unrelated to the entry/exit velocity values'', because transitions to/from ramps are processed differently and are not to be "skipped". This affects compact track/ramp combinations (such as e.g. a simple 2x2 ramp spiral) most, and combined with bouncing often makes them work not in the way one could expect. {{cite forum|144328/5705102}}

{{anchor|Tracks}}

=== Hauling route ===
A hauling route is a list of directions describing how and under what conditions a minecart will move. The proper setting up of routes is essential for a working rail system. Routes, stops, departure conditions and stockpile links are managed from the {{k|h}}auling menu.

==== Route ====
A route defines the path a minecart will take along a track, as well as under what conditions it will move or stop moving. A route is made up of stops. Stops are precisely what they sound like, a position on the track at which you want a minecart to stop. A minecart track might use as little as a single stop for a looped track, which will serve as both a starting and stopping point for the cart, or it could contain many stops, perhaps to load supplies or wait for a bridge to be manually lowered, before reaching its destination or returning to its starting point. It is important to note that you only need to place stops on a route where you actually want the cart to stop and wait for some action to occur. They are not needed to help navigate the cart along the track beyond telling it where on the track to stop.

New routes are created with the {{k|h}}auling key. Existing ones can be removed (without confirmation) with the {{k|x}} key, and also {{k|n}}icknamed. Before operating, the route must have a {{k|v}}ehicle assigned to it (this can be done with either the route or a stop selected). Assigning a full minecart to a route may result in a slow hauling job if the contents are heavy.

==== Stops ====
Stops are the individual waypoints that make up a hauling route. A given stop consists of the location of a tile, as well as conditions describing when, where, and how a cart should be moved after being stopped at that tile. Stops can be created from within the {{k|h}}auling menu, by placing the cursor over a tile and hitting {{k|s}} while highlighting the route (or a stop within) you've already designated. A minecart will begin its route at the first stop created, and continue through each subsequent stop, being guided, pushed, or ridden from each stop to the next depending on the conditions specified. In many basic minecart applications, the cart will end up at the same stop it began at, though this is not always the case. It is important to note that hauling stop order is enforced, even if there is no track. A dwarf will drag the cart overland back to a skipped stop in the route's list if your tracks bypass it somehow.

Once a stop has been placed, it is given a default set of conditions under which to move the minecart if it is stopped there. Each new stop gets the same default conditions regardless of the track it is placed upon (e.g. guide the cart to the north). For this reason new stops might get marked by yellow exclamation marks ({{DFtext|!|#ff0}}) due to invalid directions. One important thing to note is that as you place additional stops, the display will show paths between the stops you have defined. However, this is '''not''' necessarily the actual route the minecart will take once the route is in operation. For example, if a route were defined with two stops at opposite ends of a track with many twists and turns, a line will be drawn directly between those stops to show the order in which they will be visited. These route lines may crisscross all over the tracks, but so long as the track is valid end to end, the cart will follow the track from one stop to the next, even across twists, turns, and z-level changes. Stops, which are the steps that make up a route, should not be confused with Track Stops, described below.

===== Stockpile links =====
By placing the cursor on top of a stockpile and using {{k|s}}, you can create stockpile links while defining a hauling stop. Links can also be redefined by selecting them, placing the cursor over a different stockpile, and pressing {{k|p}}. The cart will then be filled by items present in its various linked stockpiles in preference to other items. Note that bins should be used with caution in stockpiles that are linked to minecarts. Bins cause problems when used with the "Desired Items" list in a stop's conditions. For example, if a minecart is set to accept only granite blocks, and to depart north when it is 100% full of granite blocks, it will not depart if any of those granite blocks are in bins, even if bins are also included in the desired items list. Two solutions to this problem exist as of v0.40.24. First, bins can be disallowed in stockpiles that are linked to stops. Alternatively, bins '''can''' be used in conjunction with minecarts provided that the minecart's departure conditions use only "any items" instead of "desired items." This option can be toggled in the advanced conditions menu for a stop, accessible via the {{key|C|}} key. The cart's contents can still be controlled by specifying what items are allowed in the linked stockpile.

===== Departure condition =====
Departure conditions involve setting conditions in which the minecart will leave on the route. Each condition includes:
# A departure mode (Guide, Ride or Push).
# An initial departure direction (NSEW). Note that this defines the initial direction of movement only. Even if a track includes many turns, as long as the initial movement direction is valid the cart will follow the minecart track thereafter.
# A timer, before which the departure condition cannot be met.
# Conditions on the amount of items in the cart.
Departure conditions are created with the {{k|n}} key. A new departure condition will read: "guide north immediately when empty of desired items". This condition can be changed between basic presets with {{k|c}}. "Advanced" mode ({{k|C}}) allows for more precise control over departure conditions: fine tuning the percentage from 0 to 100 in 25% steps ({{k|f}} and {{k|F}}), switching it being either the maximum or the minimum amount of items for the condition to be met ({{k|m}}), and whether the cart accepts all or only a specific set of items ({{k|l}}). Common to both screens are the departure mode ({{k|p}}, Push, Ride or Guide), {{k|d}}irection, and timer ({{k|t}} and {{k|T}}) options.

To have a cart only carry a specific set of items, the stop can be set to only carry "desired" items, opening the selection screen with the {{k|Enter}} key while having said stop condition selected, and toggling as desired, or it can simply be linked to a stockpile and set to depart once it is full of items from its linked stockpiles, regardless of type.

=== Track Stops ===
A Track Stop, not to be confused with a route stop, is an optional, single-tile construction which serves two purposes. First, it can be used to cancel a cart's momentum in order to slow or stop it as it passes over the Track Stop. This might be necessary if a cart were pushed down a series of ramps to its destination. Second, a Track Stop can cause a cart to automatically dump its contents as it passes over the Track Stop. Track Stops are constructed via {{k|b}} {{k|C}} {{k|S}}, and must be constructed atop an existing piece of track. If a Track Stop has been set to automatically dump a cart's contents, the cart will dump its contents in the direction indicated when it passes over the Track Stop. Depending on the friction settings chosen for the Track Stop, the cart might then stop after dumping, or it might continue on its route to another destination.

Track Stops are not mandatory; in fact, their main use is in automated rail systems. However, even in basic rail systems it can be useful to set a Track Stop to dump items: this saves time that dwarves would otherwise spend in removing items from the cart, time that is better spent driving the cart back to where it's needed. Dumping will occur even with a guided cart. '''Take care not to set Track Stops at a loading site to dump their contents''', or dwarves will never be able to fill the cart. It will dump any contents the moment they are loaded.

Counter-intuitive to their construction method, Track Stops are considered [[building]]s and must be removed by {{k|q}} {{k|x}}.
* See [[#More_on_Track_stop |More on Track Stops]]

=== Step-by-step tutorial ===

Let's construct a simple minecart route. This route will move stone blocks from an input stockpile to an output stockpile. We'll begin by creating the stockpiles:

[[File:minecart-example-1.png|Stockpiles designated.]]

The input stockpile is on the left; the output stockpile is on the right. We'll be moving blocks from left to right. Disable bins in both stockpiles, and set the input stockpile to accept only from links. Then make the stockpile take from the mason's workshop where the blocks are being produced.

Next, carve the track:

[[File:minecart-example-2.png|Track carving designation.]]

Note that the ends of the designation are uniquely shaped; this is automatic, and not anything you need to control. Now, wait for your engravers to come along and carve the track into the stone. (Your haulers will probably also fill up the input stockpile while you wait.)

In addition, while we're waiting for that to happen, we'll build an iron minecart in the forge.

[[File:minecart-example-3.png|Track carved.]]

When the track has been carved, it will look like the above (the track will be solid instead of flashing). Now, order a track stop to be constructed next to the output stockpile:

{|
| [[File:minecart-example-4.png|Track stop designation.]]
| [[File:minecart-example-5.png|Select dumping direction.]]
|}

You must press {{k|d}} three times to select the dumping direction ''before'' placing the track stop. We want our blocks to be dumped into the output stockpile east of the track stop. Then wait for a mechanic to come along and build the track stop.

[[File:minecart-example-6.png|Track stop constructed.]]

Now we'll define the actual ''route''. This is done in the {{k|h}}auling menu. Press {{k|r}} to begin defining a route. Next, move the cursor to the input end of the track, and then press {{k|s}} to define the first stop:

{|
| [[File:minecart-example-7.png|Stop 1 designation.]]
| [[File:minecart-example-8.png|Route definition, in progress.]]
|}

Move the cursor again, to the output end of the track, and press {{k|s}} again to define the second stop:

{|
| [[File:minecart-example-9.png|Stop 2 designation.]]
| [[File:minecart-example-10.png|Route definition, two stops.]]
|-
|
| [[File:minecart-example-11.png|Stops are not defined yet.]]
|}

There are several user interface features to note at this point. The stops have been positioned, but they haven't been ''defined'' yet, so there is a warning {{DFtext|!|#ff0}} symbol by each of them. In the lower right corner, we see what the {{DFtext|!|#ff0}} means. Also, note that the second stop is labeled in white, while the other two lines are grey. The white text is a selection indicator, and can be moved up and down by pressing {{k|+}}/{{k|-}}.

Next we need to define what our stops do. We want the minecart to be filled with blocks at the first stop, then travel to the second stop where it will dump its cargo, and then return. Press {{k|-}} to move the selection up to stop 1, and {{k|Enter}} to open it up. By default, the stop has three conditions:

[[File:minecart-example-12.png|Default stop definition.]]

We don't want any of these, so press {{k|x}} three times to delete them. This leaves us with a blank stop. Now we can add the conditions we actually want. Press {{k|n}} to begin adding the first condition, then {{k|d}} twice to change the direction from north to east. Then press {{k|c}} to change the condition from empty to full. This will instruct the minecart to be guided east when full of desired items.

To set the desired items, we create a stockpile link. Press {{k|s}}, then move the cursor to the input stockpile, then press {{k|p}} to select that stockpile. Now press {{k|Enter}}; this opens up a selection screen that resembles the stockpile customization screen. Move down to Blocks, {{k|e}}nable them, then (if you wish) restrict it to stone blocks.

When you've done all that, stop 1 should look like this:

[[File:minecart-example-13.png|Stop 1, defined.]]

Stop 2 is much simpler. All we need to do is have the minecart return to the input stop. So, make a condition and change the direction:

[[File:minecart-example-14.png|Stop 2, defined.]]

Finally, we just have to assign our minecart. Go back to the route definition screen, and press {{k|v}}. Select the minecart, and press {{k|Enter}}.

Now we've got everything set up:

[[File:minecart-example-15.png|Route, fully defined.]]

The V is red because the minecart hasn't been moved onto the track yet. Some dwarf will have to haul it from the forge to the first stop, by hand; this will take a while, especially if the forge is far away.

Once the minecart is in place, dwarves should fill it with blocks from the input stockpile, which will in turn be filled with blocks from the workshop where your mason has been toiling dutifully. When the minecart is full, the blocks will be dumped into the 1x1 stockpile on the right. Automatic quantum dumping!

=== Troubleshooting ===

Because of the complexity of the system, all but the most careful and experienced minecart users will encounter issues. Most route issues can be diagnosed and fixed from the {{k|h}}auling menu.

'''Symptom:''' {{DFtext|! Set dir/connect track|6:1}} message appears to the right of one or more stops

'''Possible Causes:'''
* The departure direction of the stop might be invalid. Edit the stop using {{k|Enter}} and press{{k|d}} until it is pointing in a valid direction.
* The track stop might not be built on top of a track. The track stop must be deconstructed to remedy this issue.
* Your track might not be built correctly. Make sure all connected tracks between destinations are not one-way tracks.
** This can be especially confusing with ramps. To carve a two-way track on a (natural) ramp, you must designate the ramp and one square beyond in the direction you want the track to go.
** Ramps '''must''' have a solid block on the side opposite to the track, or they will neither work nor be marked as "unusable". The solid block can be natural or constructed.
* The desired/kept items might not be configured correctly.

'''Symptom:''' The status '''0% V''' always appears to the right of one stop.

'''Possible Causes:'''
* The stop may not be set to take from a stockpile. Edit the Stop using {{k|Enter}} and make sure you see a message like "Take from Stockpile #1".
* The take conditions must correspond with the contents of the stockpile.
* The track stop may be set to dump. A track stop set to dump cannot be filled. You must either set the stop to a time-based departure or deconstruct the track stop and rebuild it without dumping. (Alternatively, with [[DFHack]] you can modify "Dump on arrival" to "No" using the {{key|q}} menu without rebuilding the stop.)
* Make sure the minecart itself has not been designated to be dumped (such as when using mass-dump).

'''Symptom:''' Dwarves fill the minecart properly, but will not move it thereafter.

'''Possible Causes:'''
* The minecart may contain items which are not included in its current stop's desired items. Check inside the minecart using the {{key|k}} and {{key|z}} keys and ensure that all items in the cart are desired items.
* The minecart may contain desired items in bins. Minecarts seem to have problems realizing that they are in fact full of desired items if some of those items are in bins, even if bins are also among the desired items for that stop. '''This cannot be solved by adding the appropriate bins to the stop's desired items.''' Either disallow bins in stockpiles you intend to load minecarts from, or set the departure conditions to rely only on percentage of total load rather than percentage of desired items using the advanced conditions menu ({{key|C}} key).

'''Symptom:''' Dwarves repeatedly attempt to load the minecart, but no items are ever loaded into it.

'''Possible Causes:'''
* This can be caused by using a Track Stop with autodumping enabled at a loading site. Every time a dwarf places an item into a cart resting on such a track stop, the item will be immediately dumped, causing unlimited, useless cart loading jobs. Autodumping Track Stops should never be used at a loading site.

'''Symptom:''' A dwarf picks up the minecart and carries it to its destination.
* See [[#Quirks|Quirks]]

=== Danger ===
Minecarts are not without <strike>danger</strike> [[fun]]. Although designating a track automatically sets the [[traffic]] designation to low, dwarves ''may'' still walk on them, and [[creature]]s ignore traffic designations altogether. If an unlucky dwarf or creature fails to [[dodger|dodge]] a minecart, they can be injured. Most of this danger can be avoided by setting the minecart {{k|h}}auling commands to guide instead of push or ride (dwarves guiding minecarts will ignore traffic restrictions), as well as by [[pasture|pasturing]] domestic animals and preventing the access of other creatures to the tracks. Note that removing the track doesn't reset that tile back to normal traffic priority, so you may wish to manually clean up traffic designation afterward. Also note that bridges that are used as tracks don't have their traffic priority changed automatically (since they're just normal bridges), which could cause dwarves to pathfind normally through dangerous minecart entrances in your fort's walls if you're not careful.

The only <s>fool</s>''dwarf''-proof method is to make the tracks inaccessible. There are several ways to create a track which works for minecarts but doesn't allow creature-traversal; the simplest is perhaps building a [[statue]] on the tracks. Other options include adding single-tile holes (minecarts moving at reasonable speed will jump the gap), vertical drops, minecart-triggered doors, small pools of liquid (4/7 water or 2/7 magma), and hostile creatures overlooking the tracks. For safety, both ends of the track should be isolated, making the dangerous center sections completely inaccessible (though maintenance access can be provided by a locked door).

Danger does not always involve living victims: careless route designation can also result in minecarts careening off tracks or colliding with each other. If this occurs, the [[item]]s may be scattered; this can cause even more hauling jobs than the minecart aimed to eliminate. Even <s>better</s> worse, scattered items, especially [[weapon]]s, can injure passing [[dwarf|dwarves]] or other [[creature]]s; in the words of Toady One the Great, "Accidental grapeshotting of the dining room should be possible now."

Of course, the danger of using minecarts means they can also be [[Trap_design#Minecarts|used as weapons]] by imaginative players.

== Advanced usage and automation ==
Minecart-specific effects are implemented via track stops, rollers and [[pressure plate]]s with "track" condition set. Since all three are considered [[building]]s, they can't be built on the same square (however convenient track stop + pressure plate would be) nor a simple ramp, and are removed by {{k|q}} {{k|x}}.

=== More on Track stop ===
Track stops are constructions that allow further automation of minecart systems via adjustable features such as braking by friction and automatic dumping of contents. They can be built from logs, bars and blocks through {{K|b}} {{K|C}} {{K|S}}; friction amount, dumping toggle and dumping direction must be set '''before''' construction, and these settings can be neither changed nor seen thereafter; however, track stops can be linked to [[pressure plate]]s or [[lever]]s to toggle friction and dumping On or Off (trigger state is inverted: switch On = track stop Off).

If a [[stockpile]] is placed on the tile that a track stop is set to dump to, it can act as a [[Exploit#Quantum_stockpiles|quantum stockpile]] and any items dumped from a minecart that match the storage settings of the stockpile will remain there and accumulate. Normally trackstops are built on top of existing track to operate on moving minecarts, but they can also be used without tracks to create [[Exploit#The_Minecart_Stop|automatic quantum stockpiles]] (see also [[#Step-by-step_tutorial|step-by-step tutorial]]). It is not always desirable to collect ALL of certain items into one quantum stockpile, such as when distributing a material to multiple separate industries. You can link your quantum stockpile to various other stockpiles, ensuring that your dwarves will keep them supplied as necessary. Because quantum stockpiles never fill up like regular stockpiles, it may be a good idea to add a switch to turn them off.

Items dumped from a minecart at a track stop (or dumped by any other means) into open space fall through z-levels until they land on a solid surface. Items falling onto a designated [[stockpile]] will automatically be considered part of that stockpile, even if the stockpile is set to disallow those items (they will, however, be automatically moved to a more appropriate stockpile, if available). Items falling on top of a minecart will '''not''' fall "inside" the minecart. Use with caution; dwarves have fragile skulls.{{bug|5945}}

=== Automated propulsion ===
==== Roller ====
{{Main|Roller}}

A '''roller''' is a [[power]]ed [[machine component]] for the automated propulsion of minecarts. They are built over the top of existing tracks with {{K|b|M|r}}, requiring a [[mechanic]], ''(length/4)+1'' [[mechanism]]s and a [[rope]]. Rollers may also be placed directly on ramps to help pull carts up Z levels. Rollers are very useful to maintain a cart's momentum along long routes, to get them to climb Z-levels without dwarfpower involved, and to get them to reach speeds unattainable by guiding dwarves. These devices are variable-length (1-10), variable-direction and variable-speed ([[Minecart#Numbers_behind_the_scene|see below]]), all traits that can be set at construction time; a roller uses two units of power per tile it is long.

Single-tile rollers transfer power in all four cardinal directions, while other rollers generally only transfer power perpendicular to their activity direction. Longer rollers can also transfer power along their activity direction if built in the correct order, although this can be hard to accomplish and is easily broken. Rollers cannot be powered from above.

Rollers have great acceleration and capped speed. Carts going faster than the roller are unaffected. If a cart moves across an active roller in the direction the roller works and moves slower than the roller's specified speed, the cart will be set to the roller's speed. A cart going against a roller's movement direction will be sent back the way it came (once again at the roller's speed), unless it was moving extremely fast: speed increment of 100000 allows to reverse carts from the full "highest" (50000) speed roller to full "highest" speed back, but ramps can accelerate a cart beyond this. {{cite forum|144328/5702453}}
A cart crossing over a roller perpendicular to its current movement direction will gain the roller's amount of speed in the perpendicular direction without directly changing its forward motion. Without an adjacent wall to constrict its movement, this will typically send a cart off the rails on a diagonal path, completely unable to follow any tracks until it collides with a wall or is otherwise brought to rest. However, if the roller is placed over a track turn and pushes ''from'' the direction of that turn's track, the turn affects carts ''after'' the roller, so they will be forced into the turn rather than derailed in a diagonal direction. {{cite forum|144328/5702453}}

{{diagram|spaces=yes|\
tracks: full:
║ ║
═╗═ ═╢═
║ ║

╢ : roller pushing from W to E
}}
If the roller is powered, carts from ''all'' directions (unless too fast) exit S, because speed imparted by the roller forces carts toward E and ''then'' into the turn.
If not powered, carts from W and N exit S, carts from E and S exit W. Carts above derail speed will ignore the turn, of course.

{{diagram|spaces=yes|\
║ ║
═╗═ ═╟═
║ ║

╟ : Roller pushing from E to W
}}
Carts from the E or W: exit W.
Carts from N: derailed diagonally, exit SW.
Carts from S: derailed diagonally, exit NW.

Rollers affects carts on a track - if placed on a floor or ramp without any tracks, they are ignored. Depowered rollers are also ignored, friction is determined by the tiles underneath.

Because of their one-way nature, rollers are unsuitable for most two-way minecart tracks (unless you set gears toggling roller A->B off while toggling A<-B rollers on). However, a minecart set to be ''guided'' is not affected by rollers at all{{cite forum|109460/3286235}} — this allows a one-way track to be used in both directions. In addition, unpowered rollers do not affect minecarts.

Care must be taken in [[glacier]]s and other extremely cold [[biome]]s, since rollers (and the machinery used to power them) will not operate when constructed on natural [[ice]] floors.

==== Impulse ramps ====
Carts can be given momentum without rollers or changing z-level through a phenomenon called "impulse ramps". A track ramp which is connected both to a wall and to a floor will ''always'' accelerate a cart towards the connected floor tile, no matter where the cart enters the tile from. This means carts can be accelerated as though dropping z-levels, even if the cart doesn't actually change z-level at all. If a track ramp faces three directions such as ╩, then two of those directions need to be facing walls for the cart to be accelerated towards the remaining direction.

Example of straight impulse acceleration:

{{diagram|spaces=yes|\
▒▒▒▒▒▒▒▒▒▒ ▒▒▒▒▒▒▒▒▒▒
═▲▲▲▲▲▲▲▲▲▲═ ═╚╚╚╚╚╚╚╚╚╚═
▒ : Wall
═ : Normal track
▲/╚ : N/E Track/Ramp
}}

If a cart enters from the left, it will speed up on every track/ramp and exit to the right going very very fast - more than one tile every step. If it enters from the right then it will bounce back impulsed by the ramp if it's going slow enough.

As another oddity, carts coming from ramps will in some cases "teleport" through most of the next tile. This is called the "checkpoint effect", and is explained in detail in the Physics section, below. This negates the deceleration of the next tile if it is a ramp "angled" in a different direction. You can just make an upward spiral alternating impulse ramps and regular upward ramps. It takes no power, is quick and cheap to build, requiring only channeling and track carving, and the cart goes up fast, but not so fast that it launches its contents.

Example of an impulse elevator:

{{diagram|spaces=yes|\
z +0 z +1 z +2 z +3
░░░░░ ░░░░░ ░░░░░ ░░░░░
░╔░░░ ░▼╚╗░ ░░▼▼░ ░░░░░
░╝░░░ ░▼░░░ ░░░╔░ ░░░▼░
░▼▼░░ ░░░░░ ░░░╝░ ░╚╗▼░
░░░░░ ░░░░░ ░░░░░ ░░░░░

░ : Wall
╔,╚,╗,╝ : Track/Ramp
▼ : Down Ramp (empty space)
}}

Note that this impulse elevator, due to the checkpoint effect and upward curved ramp effect, will not actually result in carts traveling straight up the ramp. They will lose speed, bounce off a ramp, then be accelerated back into the spiral after a 9-turn delay on both tiles on the floor where they are stopped. This is because the checkpoint effect allows carts to travel up the ramps in a single turn, but also prevents the impulse ramps from adding acceleration unless the cart is slowed to staying on the ramp for more than one turn. Initial acceleration will carry the cart up a variable number of floors before this effect occurs, but this bouncing back and forth will occur every 5 z-levels after the first time the cart stops. When the cart ''is'' traveling upwards, it will pass every tile at a rate of one tile per turn regardless of its actual speed, due to the checkpoint effect. In tracks with only a single cart, this is negligible, but when multiple carts are on the same track (such as when you place multiple carts on a magma cart lift) this can cause collisions which derail carts or cause other unexpected or undesired behaviors.

The following impulse ramp (while larger) should alleviate these problems by using a straight ramp to go upwards, preceded by an impulse ramp to exploit the checkpoint effect and negate up ramp costs. Corners still decelerate carts, so the cart will tend towards a velocity of 72k, which is derail speed. Derail speed breaks (see Controlling Speed, below) may be necessary at the top.

{{diagram|spaces=yes|\
z +0 z +1 z +2 z +3
░░░░░░ ░░░░░░ ░░░░░░ ░░░░░░
░░░░░░ ░╔╔═░░ ░░▼▼╗░ ░░░░░░
░║░░░░ ░▼░░░░ ░░░░╗░ ░░░░▼░
░╚░░░░ ░▼░░░░ ░░░░║░ ░░░░▼░
░╚▼▼░░ ░░░░░░ ░░░░░░ ░░═╝╝░
░░░░░░ ░░░░░░ ░░░░░░ ░░░░░░

░ : Wall
║,═,╔,╚,╗,╝ : Track/Ramp
▼ : Down Ramp (empty space)
}}

Also, if you want to have a cart following a below-derail speed, the following track works well:
{{diagram|spaces=yes|\
z +0 z +1 z +2 z +3
░░░░░ ░░░░░ ░░░░░ ░░░░░
░░░░░ ░══░░ ░▼▼║░ ░░░▼░
░║░░░ ░▼░░░ ░░░║░ ░░░▼░
░║▼▼░ ░▼░░░ ░░░░░ ░░══░
░░░░░ ░░░░░ ░░░░░ ░░░░░

░ : Wall
║,═ : Track/Ramp
▼ : Down Ramp (empty space)
}}
In this elevator, the cart collides with the walls in the corners, but then realigns on the ramp, picks up speed, checkpoints through the next ramp, and slams into the next wall. It is slower (10 ticks per floor) but produces reliable speeds, and will exit the impulse elevator at little more than push speeds.

A sort of opposite effect to impulse ramps also exists: ramps lacking the proper "up" and "down" connections are treated as flat track, even if they actually go up or down z-levels. This allows building "anti-impulse" slopes consisting entirely of ramps only connected up, which a minecart can travel up forty levels and more, needing no more than a single push.

=== Controlling traffic ===

==== Switching ====

As constructions or tile features, [[door]]s and other furniture can be built on tracks. A [[door]] or [[floodgate]] can be turned on or off by a [[lever]], effectively controlling the flow of automated minecarts. This may be <s>dangerous</s> [[fun]], however.
{{diagram|spaces=yes|\
->
A ════┤≡════ B
┤ : roller pushing to East
≡ : door
}}
The roller pushes the cart east, but until the "departure condition" is fulfilled, the door remains closed and blocks the path.

[[Bridge]]s can also act as tracks, but only if they're lowered or not retracted. This property can enable levers to turn tracks on and off. However, care should be taken to ensure that such bridges are never operated while a cart is on top of them, as the cart will be flung off the track. It's worth noting that it's often faster, and cheaper, to construct large bridges than long sections of constructed track.

A powered track switch can be constructed by building an "inverted" corner as illustrated below.
{{diagram|spaces=yes|\
B B
║ -> ║
║ ║
════╚═══ ════├════
A C A C
├ : roller pushing to West.
}}

If the cart is pushed East from the stop at 'A' while the roller is activated, it will arrive at 'B'. If the roller is not running, it will arrive at 'C'. The switch works by the roller first reversing the incoming cart's movement and the cart ''then'' following the track corner.

This switch is very reliable, reacts instantly to on/off signals, and carts of any speed can be switched by this design, although very fast carts will require rollers that are several tiles long, up to three. The requirement for power can be inconvenient or impractical. Non-powered solutions may use controlled derailment, or a connecting bridge.
{{diagram|spaces=yes|\
B ╥
║
║
╞════╝ ════╡
A D C
}}
Here the track between A and C is not continuous. The only continuous track is A->B, with a corner (not a T section). Fast moving carts will tend to derail at D and rejoin the track to C. Placing a door at D will prevent the derailment, so the cart continues to B. The door is operated by mechanisms elsewhere (typically, a lever, but some fun can be had with pressure plates).

Since it depends on derailing, this switch requires a very fast cart, faster than what can be achieved with rollers alone. To gain sufficient speed, a cart must be accelerated further, usually by descending several levels or through impulse ramps. The high speed makes the cart much more dangerous and harder to control.

If carts are moving too slowly to derail at the corner, a retractable bridge may be used as a connector between A and C.
{{diagram|spaces=yes|\
B╥
║
║
A╞════bbb════╡C
}}
The bridge must overlap the corner. Bridges behave like a track crossing, allowing carts to pass in a straight line. When retracted, the corner reappears, so the carts will continue to B. Bridges take 100 steps to react to a signal, necessitating rather long "lead times" when switching tracks via bridge.

As mentioned above, special care must be taken to make sure the bridge doesn't change state while the cart is passing over it. Retracting bridges will throw the cart, causing it to stop dead. Raising bridges can even crush the cart.

==== Controlling Speed ====


Minecarts can reach extremely high speeds, especially when descending multiple Z-levels. A minecart will derail at a track corner if its speed exceeds 0.5 t/st (tiles per step), '''unless''' the route in the direction of travel is blocked:

Will derail at > 0.5 t/st:

{{diagram|spaces=yes|\
in ══╗ -> derailing
║
out
}}

Will not derail at > 0.5 t/st:
{{diagram|spaces=yes|\
in ══╗O
║
out

O : wall/column.
}}

This behavior can be used to build a "speed limiter", that will ensure that when a minecart exits it is traveling below derail speed:
{{diagram|spaces=yes|\
░░░░ ░░░░░ ░░░░░
in ═╔═╗░ ░╔S╗░ ░╔S╗░
out ═╬═╝░ out ═╗═╝░ out ═╗═╝░
░╚S╝░ ░╚═╝═ in ░╚S╝░
░░░░░ ░░░░ ║░░░
in
░ : wall
S : Track Stop (High Friction or lower)
}}
If the minecart is traveling below derailment speed, it will not be affected; if above, will be slowed down and checked again. Granted, you could do the same just with track turns, but it may take a lot of turns and time.

Since all the derailings, bounces and ramps can impart a sideway component of speed small enough to start visible drift many tiles away (say, [[Fun|in the middle of a bridge]]), track turns have one more use: forcing the carts to move strictly along the grid directions. Carts passing a turn below derailing speed convert one component of velocity into another, thus eliminating the drift.

=== Loading liquids ===
[[Water]] and [[magma]] can also be loaded into minecarts by submerging them to a depth of at least 6/7 while standing still or moving at speeds of at most 10000. Loading fluids onto minecarts can be difficult because the added friction provided by fluids can stop a cart in a submerged tile. Curiously, filling a minecart with magma does not injure a dwarf ''riding'' it. A minecart will hold enough fluid to increase the depth of a single tile by 2. This amount is listed as 833 units, which weigh 459Γ (water) or 999Γ (magma). An iron or steel cart filled with magma weighs 1313Γ, while an adamantine cart filled with magma weighs 1007Γ. Since you need a minecart above the liquid's level, possible arrangements may include pressure-activated sluices, rollers (with magma-safe chains for magma), pouring from above to "submerge" it briefly on the same level and drain excess away (dig deeper and leave a vaporizer, though if you could have power for rollers, may as well use a pump) and exploits with ramps (not necessarily impulse ramps, "same height" passing dip does it).
The liquids can be dumped by a constructed track stop.

== Quirks ==
This little quirk concerns dwarf-managed minecarts. If a track which was previously open becomes blocked (ex. flipping a switch connected to a floodgate you've built on the track to raise it) and the conditions for departure are met, instead of refusing to ride/guide the minecart or ride/guide it until it reaches the obstacle, the dwarf will pick up the minecart off the tracks and haul it to its scheduled destination on foot. If the distance is long enough and the weight of the cart heavy enough (due to being filled with heavy items such as stones), the dwarf may drop the cart because of fatigue/hunger/thirst before reaching the destination. This will cancel that vehicle setting job and make another dwarf come by and attempt to haul the cart to the nearest appropriate stockpile where another dwarf will pick up the cart and attempt to haul it to its initial stop. If the stockpile is far enough from initial stop, this second dwarf who is attempting to place the minecart on its tracks may also drop the minecart out of fatigue/hunger/thirst creating a loop that will go on until a dwarf with enough endurance manages to place the minecart where it belongs.

In fact, it seems dwarves are more than happy to attempt to carry a minecart from one stop to another even if just waiting until the track is open again would be the more sane option.

Dwarves will also carry a minecart to its next stop if the direction specified is incorrect (or invalid). This can often occur when using the default departure settings and forgetting to set the direction of each condition.

Dwarves can admire buildings while riding mine carts. Dwarves will not fall asleep during a ride (at least not from being drowsy). If riding on a continuous powered track loop, the dwarf will die of dehydration/starvation as they can not jump off to get sustenance{{cite forum|109460/3377228}}. Dwarves riding in submerged minecarts will gain experience in [[swimming]].{{cite forum|129889}}

Tracks block wagon access to trade depots, unless they're on a ramp. [[Bridge]]s can also be used, as they function as tracks but do not block wagons.

== Physics ==


Minecart physics depend greatly on the departure mode set in the route stop conditions.

When set to "Push" or "Ride", minecarts will move according to the regular laws of momentum, gaining speed when going downhill, losing it slowly due to friction when on a flat plane, and more quickly when going uphill. In these modes, minecarts will move in a straight line until they either are brought to a stop by friction or an obstacle, or until they encounter a turn. A minecart will roll straight past "blocked" ends of T-junctions or track ends, they have no power to restrict a cart's movement. The cart's behavior is largely independent of the weight of its contents (including fluids and dwarves): heavily loaded carts gain more momentum when accelerating, but this only plays a role in collisions: a heavy cart gains just as much speed and is as easy to stop as a light one. In either case, dwarves can not push nor ride an unpowered cart up a ramp, bouncing back the direction it came. At best, this is a waste of time; at worst, it will give your cart-pushing dwarf a [[fun|fun surprise]]. To solve this, the player can either use Rollers (see below) or set the cart to be Guided.

The difference between "Push" and "Ride" is whether the dwarf will go along with the cart or not.
{{DFtext|Push}}: the dwarf will give the cart an initial push, not enough to go up a ramp, but enough to go some way along flat track, and the dwarf will remain at the first stop, ready for a new job.
{{DFtext|Ride}}: the dwarf will give the cart the same initial push and then hop aboard the cart riding with it to the next stop.
{{DFtext|Guide}}: minecarts seem to ignore all laws of physics. That is:
*Ignore the weight of any and all items inside. Therefore:
**Move at the speed of the dwarf that is guiding them. It is thus recommended to pick the most [[attribute#Agility|agile]] of your dwarves for cart-guiding tasks.
*Ignore working rollers.
*Will ''not'' collide with other guided carts even when a full frontal collision would be expected.
*Will go up ramps like nobody's business.
This is therefore the recommended method of transport for simple non-powered rail systems, despite it diverting a dwarf from other, potentially more important tasks.

Some samples with behavior:
{{diagram|spaces=yes|\
A <-> B A <-> C A <-> B
B B B
║ ║ ║
A══╝ A══╩══C A══╬╗
You can only go A->B ╚╝
Works when the cart Works
is in Guide mode.
}}
In the second example above, a cart "pushed" from B will go over the junction and roll off into the unknown south.

=== Track Direction Irrelevance ===
Carts that are traveling independently, (that is, not guided,) only care that tracks ''are'' on the tile, not which direction the tracks actually move. Tracks respect only curves (with two exits) and ramps.

This means, for example, that the following tracks, when a (non-guided) cart travels from West-to-East, are functionally identical in effect:

{{diagram|spaces=yes|\
A════════════B A╬║╚╔╣╩╦╠╥╨╞╡B
}}

This is because so far as the cart is concerned, only ramps and curves with two exits where the exit in the path they are traveling matters.

Hence, if a minecart encounters the end of the track or a T junction with no "exit" in its movement direction, it will simply leave the track and continue on its course in a straight line until it encounters an obstacle, slows to a stop, or encounters another track even if the tile at which it joins the new track instantly sends it around a corner.

In fact, a "║", a "╦", a "╬", and a "╥" are ''only different in appearance'', and are ignored by the cart, which will continue in its current direction, regardless of the track.

Carts only check for curves when they are halfway through a tile. When they get there, they look to see if their path has no exit. (That is, if it is traveling East, it checks if there is an East exit.) If there is, it ignores all other track directions, and keeps traveling. If there is not, it checks to see if there are only two exits to the track, and if one of those directions was the direction it "came from". (That is, if traveling from the East, it checks if there is a valid exit to the West, and if so, if there is either a North exit or a South exit.) If there is not, it ignores the track anyway, and keeps on traveling as though it were still on track. If there is, it will subtract 1000 from the velocity of the cart, and redirect all forward velocity to the direction of the curve. This change in the direction of velocity ''overwrites'' any "diagonal" velocity, which can prevent diagonal velocity derailments, but any perpendicular velocity is not preserved, and is instead discarded.

=== Valid and Invalid Ramps ===
Ramps are functionally defined for cart purposes as being a tile which exerts an acceleration force upon its "downward slope", and which allows connection to tracks a z-level above or below. This downward slope requires a cart to have one ''and exactly one'' carved exit to the tile that is the "bottom" of the ramp. Ramps accelerate carts in this "downward" direction (possibly leading to diagonal movement, below), and the deceleration of an "uphill" ramp is actually just the acceleration being applied against the direction of a cart's movement.

This is where players can find an exploit in the behavior of ramps - if there are ''two'' "downhill" exits to a ramp (such as a "T junction" on a ramp where only one exit faces a wall), then the ramp provides no acceleration ''or'' deceleration, allowing carts to travel up ramps without any loss of momentum except for the standard "flat track" deceleration, because as far as the cart is concerned, the track ''is'' flat. (A T junction is also not a curve, so the track is considered flat and straight no matter what direction the cart is traveling.)

Similar effects can be achieved when there are ''no'' "downhill" exits to a ramp. This may be the case if you have, for example, an East-West track with a one-tile channel with a ramp in it. The cart will travel through the "dip" with no change in velocity. It can also be the case if you abuse the Track Direction Irrelevance, above, and set only exits ''up'' the ramp, and none leading ''down'' the ramp. For example, if a cart is traveling from West to East up a slope, only carving East exits on each tile of ramp will make the cart travel up the ramp, and then recognize the tile it is on as being a "flat" tile, thus ignoring any deceleration from traveling uphill.

Note that this effect only reliably occurs at below-derail speeds as the cart will treat the ramp as an invitation for a ramp jump otherwise. (This almost always results in a collision with a wall that will stop forward progress.)

=== Falling ===
When falling, a minecart appears to cause no damage upon collision, possibly to allow cart "stacking" across Z-levels.{{cite devlog|2012|04|06}} A dwarf riding in a minecart that is dropped multiple z-levels suffers normal fall damage. Minecarts can fall through up/down stairs.

While airborne, carts do not feel the effects of friction in any horizontal direction, and will continue until they strike an obstacle. Carts that land on tracks instantly re-rail themselves regardless of track directionality.

Falling carts accelerate similarly to the way that a ramp will accelerate a cart in a special z-only velocity that only applies to airborne carts. (Actually, acceleration due to gravity in freefall seems curiously slightly ''slower'' than ramp acceleration.) Ramp acceleration, while it logically should be partially z-directional, is only recorded as x- or y-directional, and there is no translation of z-directional velocity upon landing. Landing carts zero out their vertical velocity upon landing, even when landing on ramps, although carts that had horizontal momentum while falling preserve it.

This means a cart falling (from a hatch, thus with no horizontal speed) onto a track ramp is accelerated as if starting from the middle of the ramp - i.e. to the same speed, no matter how many Z-levels it was dropped, vertical velocity is negated. {{cite forum|144328/5701211}}

Carts falling onto a floor can, however, cause damage to creatures ''one tile below the floor''. This can be used in an [[exploit]] called a "thumper", where carts are caused to repeatedly fall on a floor above an entrance to the fort, inflicting significant damage (as though it were a collision) on those below the cart.

=== Cart Jumps ===
Carts that cross off of "up" ramps relative to their current direction of travel, which do not have a ceiling above them, are traveling above derail speed, and do not have valid ramp track before them can translate a portion of their horizontal velocity into vertical velocity, causing a cart to be projected into the air until vertical velocity is negated and overcome by the gravitational acceleration. Because downwards acceleration is applied per-tick, this creates a reasonable facsimile of the parabolic motion of an actual object rolled up a ramp and launched with significant speed.

{{diagram|spaces=yes|\
z0 z0 hiding ramps z+1 A z+1 B (hidden ramp)
▒▒▒▒▒▒▒▒▒▒▒▒ ▒▒▒▒▒▒▒▒▒▒▒▒ ▒▒▒▒▒▒▒▒▒▒▒▒ ▒▒▒▒▒▒▒▒▒▒▒▒
═▲▲▲▲▲══▲▒▲═ ═╚╚╚╚╚═══▒══ ▼▼▼▼▼ ▼═▼ ▼▼▼▼▼ ▼╚▼
▒ : Wall
═ : track
▲ : Ramp
}}
In this diagram, if there is no ceiling above it, the track in z+1 A will launch its carts airborne when they travel across the ramp. z+1 B (with a ramp on the tile on the hill) will not launch the cart. The cart would also not be launched with ''any'' valid ramp, even if it does not travel in an appropriate direction, such as North/South (which the cart will ignore, as it is not a curve, anyway, although it may produce acceleration that may cause diagonal movement.)

Carts that are traveling at derail velocity will also start "jumping" from the track if it hits an un-tracked tile, flying over and ignoring any tracks until it is ready to land. Carts that land upon tracked tiles re-rail themselves, and clever designers use this feature to jump over curved track sections in one direction or another. (Retracting bridges over untracked tiles can cause jumps or not cause jumps depending upon the status of the bridge.) Minecart speed must be carefully regulated to ensure reliability of jump length.

Hitting untracked tiles at around 70k velocity creates a vertical component to acceleration that allows for jumps of around 6 (horizontal) tiles that do not actually leave the z-level the cart is on, but which do apply z-direction velocity on the cart, as per falling.

Carts that approach a downward slope at a high enough velocity will also make a jump, (or rather, ignore the ramp and fly forwards) but will not do so if the Checkpoint Effect (below) is exploited through an impulse ramp before the actual downhill as the impulse ramp "tricks" the cart into thinking it has already started going downhill. The cart will also not fly off the ramp if there is a wall and ceiling preventing any motion but going down the ramp.

=== Skipping ===
If a minecart is moving fast enough, it can skip over [[water]] or [[magma]], making splashes of [[mist]] (or [[magma mist]]) as it attempts to move on them horizontally. This horizontal movement is independent of the minecart and its content's [[weight]].

Skipping causes significant friction on the cart, and even a cart going at max speed from ramps can only make about 50 tiles without requiring re-acceleration. (Carts that decelerate enough that they do not trigger the skipping effect will, of course, sink.)

=== Corner Ramp Derail ===

Corners on upward ramps can cause diagonal movement, forcing a derail even if the cart has a wall next to it, which will force a stop when it touches a wall that forces dwarves to manually reset the cart.

This is caused by the fact that a cart, after turning the bend in the track halfway through the length of the tile, will still "accelerate down", which is now perpendicular to the movement of the cart, causing acceleration to occur in two directions. (Down corner ramps do not have this problem, as when they pass the halfway point, all perpendicular motion is added to forward motion, and after that curve, all downward acceleration is in the forward direction.)

There are two fixes to this problem. One is to simply not put corners on up ramps. The other is to take advantage of the Checkpoint Effect, below, by making a ramp (possibly including an impulse ramp) one tile in front of the ramp to make it skip through most of the tile before sideways momentum can be built.

=== Checkpoint Effect ===
The checkpoint effect, [http://www.bay12forums.com/smf/index.php?topic=144328.0 explained in depth by Larix], is an odd and highly exploitable feature of ramps where minecarts "teleport" through the next tile of track, ignoring nearly all minecart physics (except that they stop at all walls or other obstacles and not only respect curves, but will take them even when they would otherwise derail) and passing through that tile in just a single tick, and into the next tile at the halfway point.

This effect occurs when a cart leaves a downward ramp for any other direction of tile. (This includes ramps which accelerate in different directions, even a ramp which goes from accelerating East to accelerating North due to a bend in a chain of standard down ramps in a curve.) This allows, for example, two valid straight ramps directly next to one another with a cart dropped onto one or the other with no momentum to have the cart pick up acceleration going "down" the ramp as normal, but then flying up through the "up" ramp it travels into with no loss of momentum, as though it had come from an impulse ramp. If the two ramps had at least one space of distance between them, and then a cart were dropped in, the cart would instead "rock" back and forth between the two ramps.

This seems to be because ramps have a slightly longer length than regular tiles - 144,000, rather than 100,000 distance. When this "snaps back" after a ramp, it seems to project the cart suddenly further along the track, making it jump a tile ahead even when otherwise moving at relatively low speeds.

This [[bug]] is the cause of a ''wide array'' of unexpected behavior among people who do not take this bug into account. It causes derailments or failure to climb up seemingly valid impulse elevators. In general, it makes a system that behaves extremely counter-intuitively, and operates ''any time a cart encounters a valid ramp''. At the same time, when its effect is accounted for, it is highly exploitable: It causes "perpetual motion devices" using no power when two opposing ramps are placed next to one another, since the "uphill" effect of the opposing ramp is ignored, preventing deceleration.

Another useful thing to note about this exploit is that carts traveling at no less than 72,000 or so speed (enough to travel half a ramp tile in a single tick) can travel through every tile in just one tick at no change in velocity as long as the tiles alternate between impulse ramp or actual down ramp and any other tile type. The cart checkpoints through the non-down-ramp tiles, and can pass through the (impulse) down ramp tiles in a single tick, before they can actually start gaining momentum.

{{diagram|spaces=yes|\
▒▒▒▒▒▒▒▒▒▒ ▒▒▒▒▒▒▒▒▒▒
═▲═▲═▲═▲═▲═ ═╚═╚═╚═╚═╚═
▒ : Wall
═ : Normal track
▲/╚ : N/E Track/Ramp
}}

If the cart enters from the West at less than 72,000 speed, some of those ramps will cause Eastward acceleration.

This means that an impulse ramp not contiguous to other impulse ramps has a top speed of around 75k:

{{diagram|spaces=yes|\
▒▒▒▒▒ ▒▒▒▒▒
▒╔═╗▒ ▒╔═╗▒
▒╚▲╝▒ ▒╚╗╝▒
▒▒▒▒▒ ▒▒▒▒▒
}}
This setup makes a cart that travels clockwise at a speed that fluctuates around 75k velocity. If the cart has more than 72k velocity, it fails to accelerate in the ramp, as it leaves the ramp in a single turn due to checkpointing to the halfway point. After that, the curves sap 1k velocity, and every tick saps 10 velocity.

Two contiguous impulse ramps with a same-facing "downwards slope", however, do not suffer the checkpoint effect in the second tile, giving functionally triple the space to accelerate. This means it will add velocity (at the standard rate of 4.9k per tick) up to a maximum speed of 216k.
{{diagram|spaces=yes|\
▒▒▒▒▒▒ ▒▒▒▒▒▒
▒╔══╗▒ ▒╔══╗▒
▒╚▲▲╝▒ ▒╚╗╗╝▒
▒▒▒▒▒▒ ▒▒▒▒▒▒
}}
This example results in a cart moving three times as fast as the previous cart.

Three successive ramps results in the highest attainable speeds.

In practical terms, this means that only consecutive ramps should be used for high acceleration, but singleton ramps can be used to have speeds that are somewhat regulated.

=== Stacking ===
If a minecart lands on top of another minecart, they may form a stack, with the upper cart on the z-level above the lower. Subsequent carts do not form a stack, but rather quantum stockpile in the same space. This behaviour is useful for [[megaprojects]] and [[trap design]] with minecarts as the weaponry. Moderation should still be exercised: carts take longer to fall into a "stacking" tile already occupied by other carts and will spend that time "hanging" in the air above the stack. This can lead to following carts striking them, which can cause all kinds of malfunctions. The extra time is two game steps for every cart already in the stack, which doesn't hurt stacks of ten carts very much but makes stacks of 100+ rather impractical.

These minecarts on the upper level generally need to be struck with another minecart to move out, or have their support removed. The latter option is safest done by shooting it away with another minecart, manual removal of a stack-supporting cart typically causes the next cart from the stack to [[fun|fall on top]] of the hauler.

=== Perfectly Elastic Collisions ===
Minecart collisions are perfectly elastic, meaning that not only do minecarts not take damage, but that two carts that are rolling which have frontal collisions of near-similar speed, and where one cart is no more than twice the mass of the other cart, will result in a billiard-ball-like effect of the lighter cart bouncing off the heavier cart with a proportional speed increase dependent upon the relative momentum behind the heavier cart.

Using this trick with carts already at the 270,000 maximum speed from ramps can result in "supersonic" carts traveling at speeds in the millions (travelling a dozen tiles per tick), but where they are suddenly subject to 10,000 units of "terminal velocity" friction per tick. [http://www.bay12forums.com/smf/index.php?topic=137557.0 Thread with SCIENCE here].

While hypothetically capable of launching a minecart into orbit when used in conjunction with a ramp, no cargo can be contained in the launched cart, as the collisions will force ejections of the cargo. Your "unwilling volunteer" [[goblin]] space pioneers will simply become paste underneath the wheels of an extreme high-speed cart.

=== Numbers behind the scene ===

According to early research by '''expwnent'''{{cite forum|112831/3536975}}:

The minecart has a variable for speed. Speed is measured in tiles/100000 ticks, so a speed of one hundred thousand means one tile per tick. By going down a large number of ramps, a maximum speed of 270,000 can be reached, which presents the limit for most practical applications. Short bursts of (much) higher speeds are possible through carefully planned collisions of high-speed carts {{cite forum|137557/5145499}}.

Every tick the cart accumulates distance units, as well as slows down depending on current tile (speed is reduced by "friction" of the tile). The cart will move to the next tile the tick before accumulating 100000 distance units, (or several tiles in case of great speed), then the leftover distance units are added to the default 100000 distance u. of the next tile. Since most deceleration and acceleration is applied per step, with the notable exception of corners, a cart going at twice the speed of another one can cover about four times the distance in a straight line, but only twice the distance along a winding track with very many corners.

A push will teleport a cart to the beginning of the next tile (NOT the middle!) in one tick with 19990 speed (10 speed is lost due to track friction), while a roller will give a cart the roller's set speed, and it will start to accumulate regular track friction past the middle of the roller tile. Some track features will affect a minecart when it is past the middle of the previous tile: entering a ramp or a hole/drop will happen when the cart has left the middle of the previous tile, and the ramp will gain additional distance unit depending on the leftover units from the previous tile. When a cart leaves a ramp it will emerge after one tick in the middle of the next regular tile, so its entry coordinate is "50000-speed+friction". Rollers also affect the speed of minecart from the middle of the previous tile.

Friction of tiles:
{| class="wikitable"
|-
! Tile
! Friction
! Comment
|-
| Tracks
| 10
|-
| Ground/Floor
| 200
|-
| Unusable ramp
| 10
|-
| Upwards ramp
| 4910 (10+4900)
|-
| Downwards ramp
| -4890 (10-4900)
|-
| Roller
| ±100000 (but capped by the set speed)
|-
| Corner track
| 10
| Speed reduced by 1000 upon leaving the corner tile
|-
| Track stop (highest)
| 50000
|-
| Track stop (high)
| 10000
|-
| Track stop (medium)
| 500
|-
| Track stop (low)
| 50
|-
| Track stop (lowest)
| 10
|-
| Water 1-6
| Additional (WaterLevel - 1) * 100
| rowspan="2" | [[#Skipping|See Skipping]]
|-
| Magma 1-6
| Additional (WaterLevel - 1) * 500
|-
| Empty space
| 0
|}

Water of depth 7/7 provides a friction of about 10000 per step, as does maximum-depth magma. This higher friction may not apply to very slow-moving carts.

Impulse sources:
{| class="wikitable"
|-
! Feature
! Speed
|-
| Push
| 20000
|-
| Roller lowest
| 10000
|-
| Roller low
| 20000
|-
| Roller medium
| 30000
|-
| Roller high
| 40000
|-
| Roller Highest
| 50000
|-
|}

== Non-standard uses ==
Minecarts include some interesting characteristics that have motivated uses beyond hauling. They can be useful for creating fully-automated [[exploit|quantum stockpiles]] and [[garbage disposal]]s. Storing perishable goods (meat, meals, etc.) inside a minecart appears to guard against rot and vermin.
Minecarts can be [[Trap_design#Minecarts|used as weapons]], or as (hopefully non-fatal) triggers to restart stalled [[healthcare]]. They can also be used to time/control game events, either using a basic [[repeater]] or much more advanced [[minecart logic]].
Minecarts trigger [[pressure plate]]s, which means a trap can be designed to trigger when a thief attempts to steal a minecart.
A pressure plate can be used as automatic and more precise custom "launch when full enough" system - as long as weight of your minecarts stays the same. You cannot build a hatch or roller on the same tile, so launch by bumping with another cart. {{cite forum|15096/4580050}}
Dwarves riding minecarts can attack enemies within reach (which goes back to dev log). This applies to shooting, and they actually can hit targets while riding by.{{cite forum|109460/5266119}} Whether a minecart protects the rider and how it interacts with dodging is not known yet. Minecart riders can also [[Swimming#Minecart_training|train swimming]] and [[Megaprojects#Surveillance_Track|detect ambushers]].

== Adventure mode ==
In addition to being used for hauling, minecarts can also be ridden in [[adventure mode]]. (Adapted from forum thread {{cite forum|122903/4258212}})

# If the minecart is in your inventory, drop it. If it is already on the ground, proceed to step 2.
# Press {{k|u}} when you are 1 tile away from the minecart (or standing on the same tile as the minecart).
# You will be presented with the following options:
[[File:minecart adventure mode menu.png|left]]
{{clear}}
* If you {{DFtext|Push}} the minecart, it will move a few tiles in the direction you chose. Physics comes into play here, so it will gain/lose speed depending on the usual factors.
* If you {{DFtext|Ride}} the minecart, you will hop into the minecart, even if you were a tile away, and it will move in the chosen direction with you in it. It will gain/lose speed depending on the usual factors. Whilst the minecart is in motion, you should press {{k|.}} to skip your turn; if you attempt to move whilst the minecart is still in motion, the laws of physics come into play, and you will take [[wound|damage]]. Alternatively, you can push the minecart whilst it's still in motion (although it's unclear how one can bend [[physics]] so as to push a moving minecart whilst inside the minecart). If you push it in the same direction you are already travelling in, you will greatly increase the minecart's velocity. You can also push it in different directions, and this will cause it to gradually change direction-the amount of pushes this requires depends on the minecart's velocity. Once the minecart has stopped moving, you may move out of it safely, or you may want to give it another push. Note that if you push a minecart right after having ridden it (still on the same tile as the minecart), it will act as though you chose to ''ride'' it.

If you want to test this out without creating an adventurer, the [[object testing arena]] allows you to spawn minecarts ({{k|k}}-{{k|c}}-{{k|n}})

== Forging and Melting ==
* Metal minecarts cost '''two''' [[metal]] bars to forge, or '''six''' [[adamantine]] wafers.
* When a non-adamantine metal minecart is melted down, it will return '''1.8''' metal bars, for an '''efficiency of 90%'''.
* When an adamantine minecart is melted down, it will produce '''1.8''' wafers, for an '''efficiency of 30%'''.

== See also ==
* [http://www.bay12forums.com/smf/index.php?topic=109460.0 The "How Does Minecart" Thread] by '''Girlinhat''' et al.
* [http://www.bay12forums.com/smf/index.php?topic=112831.0 SCIENCE: Quantifying minecart physics] by '''Snaake''' et al.
* [http://www.bay12forums.com/smf/index.php?topic=129676.0 How to build a Multi-cart Ore to Magma Minecart Project without needing power] by '''WanderingKid'''.
* [http://www.bay12forums.com/smf/index.php?topic=144328.0 My very own Minecart Education Thread. Ten Lessons, now complete.] by '''Larix'''.

== Bugs ==
*A dwarf will drop her [[child|baby]], if she has one, when boarding a minecart set to be ridden.
*Dwarves have no concept of traffic safety and will walk into busy minecart lines to retrieve objects, often with deadly consequences. This is especially problematic in [[Swimming#Minecart_training|clever applications]] depending on dwarves riding the carts very frequently, because they have a bad habit of dumping their worn clothes on the tracks after a minecart ride. Adding an automatically-operated [[hatch cover]] at the end of such a ride can help prevent [[unfortunate accident]]s.
*Dwarves cannot guide a minecart through an unlocked door unless another dwarf opens the door.{{bug|6056}}
*It is possible for a creature and minecart moving towards each other to pass without collision if they exchange tiles in the same tick.
*After a minecart ride, a dwarf will sometimes haul the minecart to a storage stockpile, leaving another dwarf to haul the vehicle back to the route.
*Minecarts falling onto a floor injure creatures in the tile below the floor.{{bug|6068}}
*A minecart's initial velocity is not affected by weight, when pushed or launched from rollers.{{bug|6296}}
*Removing a stop that has a vehicle waiting on it may cause the game to crash.{{bug|5980}}

{{Category|Fortress mode}}
{{Category|Interface}}

[[ru:Minecart]]

Minecart

2015-06-18T20:13:38Z

NW Kohaku: /* Impulse ramps */

{{Quality|Masterwork|08:15, 19 May 2015 (UTC)}}
{{av}}
A '''minecart''' is a [[tool]] intended for [[hauling]], introduced in version 0.34.08. It can be made of [[wood]] at a [[carpenter's workshop]] or [[metal]] at a [[metalsmith's forge]] (using the [[Metal crafter|metalcrafting]] labor.) Minecarts store up to five times as many items as [[wheelbarrow]]s and are quite a bit faster than dwarves hauling objects by hand, but have the disadvantages of requiring a dedicated track network, a complex route planning phase, and the possibility of dwarves [[Fun|blundering into the path of carts filled with lead ore]]. Tracks may be carved into stone, or [[Construction|constructed]]; the latter allows above-ground routes, but these are more difficult to set up due to their additional [[building material|material requirements]].

Just like wheelbarrows, minecarts are considered [[item]]s and are stored in a [[furniture]] [[stockpile]]. Despite their five-times-greater capacity, they are only 33% larger than wheelbarrows and are identical in base [[item value|value]] when made from the same [[material]] (the value may differ due to the [[item quality]]). [[thief|Thieves]] or even mischievous animals can steal minecarts, even when they are moving on a track{{cite forum|109460/3289070}}. However, minecarts moving fast enough or being ridden cannot be stolen.

Although most of the utility of minecarts is in [[fortress mode]], an [[adventure mode|adventurer]] can also ride in a minecart. Adventurers can also pick up and relocate minecarts.

The invention of minecarts revolutionized the [[minecart logic|Science of Dwarfputing]] by enabling smaller, faster logic systems to be built.

== Basic Minecart Usage ==
Minecarts can be used to swiftly transport dwarves, [[flow|fluids]], and/or large amounts of items, but before you have a functional minecart there are several preconditions that need to be met. First of all you need an actual minecart, constructed either in a [[carpenter's workshop]] or [[metalsmith's forge]]. For the minecart to be able to move you also need to carve (with {{k|d}} {{k|T}}) or construct (with {{k|b}} {{k|C}} {{k|T}}) a track, which could be as simple as a straight line. Finally you need to construct stops on your track (with {{k|b}} {{k|C}} {{k|S}}) where the minecart will start and stop.

After you have created the stops and assigned a cart to the track, you must create logic routes connecting several stops and designate starting conditions for each stop. This is done with the {{k|h}}auling key. The most basic conditions are how the cart's movement is initiated and in which direction the cart should start moving. Carts can be either be Pushed (a dwarf stands at a stop and gives the cart a single push) or Guided (a dwarf continually pushes the cart forward, guiding it along the track). The [[hauling]] [[labor]] required for pushing and guiding carts is called "Push/Haul Vehicles" and is turned on by default.

To control which items to transport you can add conditions specifying: (1) which kind of items to be loaded, and unloaded, (2) stockpile links to define which stockpile(s) the items should be un/loaded to and from.

===Capacity and weights ===
Minecarts have five times the [[Weight|capacity]] of [[wheelbarrow]]s.

'''Examples of the capacity of one cart'''
{| class="wikitable"
|-
! Item
! Amount
|-
| [[stone]]
| 5
|-
| [[wood|log]]
| 10
|-
| [[block]]/[[bar]]
| 83
|-
| [[Kitchen|prepared meals]]
| 500
|-
| [[Trap_component#Spiked_ball|spiked balls]]
| 500
|-
| [[Weapon#Native_weapons|mace]]
| 625
|-
| [[Weapon#Native_weapons|spears]]
| 1250
|-
| [[cloth]]
| 2500
|}

The weight of the loaded minecart does not affect the initial velocity received from pushing or launching from a roller. However, the load of a minecart ''does'' affect whether a [[pressure plate]] triggers or not, based on the pressure plate's setting.

'''Weights of different carts'''

{| class="wikitable"
|-
! Type of cart
! Empty cart
! Fully loaded (items)
|-
| oaken minecart
| 28Γ
| 378Γ (10 oak logs)
|-
| platinum minecart
| 856Γ
| 10482Γ (83 gold bars)
|}

The weight of a minecart is one twenty-fifth (1/25) the [[density]] of its material in Urists. Because pressure plates can be set to trigger at intervals of 50 Urists, minecarts with weights just under a multiple of 50 are ideal for switching based on whether they're full or empty. The best minecart materials for full/empty switching are as follows:

{| class="wikitable sortable"
|-
! Material !! Minecart weight !! Content weight required to trigger !! Banana roasts required to trigger (for scale)
|-
| [[Bismuth]] (moods only) || 391 || 9 || 15
|-
| [[Brass]] || 342 || 8 || 14
|-
| [[Electrum]] || 596 || 4 || 7
|-
| [[Fine pewter]] || 291 || 9 || 15
|-
| [[Glumprong]] || 48 || 2 || 4
|-
| [[Lay pewter]] || 291 || 9 || 15
|-
| [[Nickel silver]] || 346 || 4 || 7
|-
| [[Tin]] || 291 || 9 || 15
|-
| [[Trifle pewter]] || 291 || 9 || 15
|}

=== Creating tracks ===
Minecart tracks are made up of contiguous track, tracked ramp, or bridge tiles. Track tiles and tracked ramp tiles have a direction or series of directions associated with them. These directions dictate which directions a minecart on a given tile may move from that tile. For example, a Track NE (northeast) tile allows a minecart on it to move either north or east from its present position. Therefore, if you want your minecart to move east along a straight piece of track, then return west using that same track, you would need to use EW tracks so that the cart could travel east initially, then return west over the same track. Excluding designs in which the cart will "jump" tracks via a drop or other ramp, tracks must be valid end to end to work for most looped or straight-track applications. A single east only track tile in your line of east-west tracks will cause any route using the track to fail the moment it tries to go the wrong way over that tile. Minecart tracks can be built in two ways: Engraved/carved or constructed. A given minecart track need not use engraved or constructed elements exclusively, as the two methods can be used interchangeably depending on the needs of a given section of track. The way the tracks are built is slightly different between the two, as explained below.

====Simple tracks====

'''Carved'''

A single-tile wide strip of natural stone can be designated to be [[Engraver|carved]] (with {{K|d}} {{k|T}}), which will create a straight two-way track. The creation of corners, crossings, and T-junctions is as simple as designating another strip of track that overlaps an existent or newly designated track. Engraved tracks are removed by [[smoothing]] the rock they're on, which results in a smooth floor (that can be re-engraved if necessary), or by building a [[floor]] on top and subsequently removing it. Dwarves can carve corner tracks in one pass by designating the track carving twice and canceling unwanted carvings (with {{K|d}} {{K|x}}). Tracks can be engraved in any natural floor tile, rough, smooth and even over engravings, providing an easy method to remove low-quality or undesired floor engravings. Once a track has been engraved, it's important to check the track directions for each tile in the route carefully to make sure no mistakes were made by yourself or the game's track engraving logic.

'''Constructed'''

Tracks can also be built as regular [[construction]]s (through {{K|b}} {{K|C}} {{K|T}}). This method is resource-expensive, since each track tile requires one stone, [[bar]], or [[block]] for construction, and time-consuming, since you can't designate strips longer than 10 tiles at a time. Corners, crossings, T-junctions, and ramps also have to be designated individually. However, it is usually the only way to build tracks above ground or on soil (barring the [[Obsidian farming|creation of obsidian]]). Constructed tracks are designated for removal like any regular construction; be aware that removing track ramps built on top of natural ones will also remove the original ramp, leaving a flat floor.

====Ramps====

'''Carved'''

The carving of natural ramps is a little more confusing: to carve a two-way track on a ramp (natural only, does not work on constructed ramps), you must designate the track '''starting on the ramp and one square beyond''' in the direction you want the track to go. For the side of the ramp square you want to head upward, there '''must''' be either a natural or constructed wall in the square next to it, otherwise the game assumes you are trying to carve it on the same level -- this can result in the track being carved underneath a door or other object. If you have accidentally done this, you can correct it by smoothing the ramp and constructing a single square of wall next to it, then re-carving the ramp correctly. (However, the wall must stay there permanently; removing it will disconnect the track.)

'''Constructed'''

When constructing track ramps, the stated direction should be the same as the connected tracks. For example, a track going up from West to East would require, starting from the West, a Track (EW), a Track/Ramp (EW) and a Wall behind the ramp, underneath the section of track above it. Incorrectly placed ramps result in minecarts ignoring the ramp and crashing into the supporting wall. They will not, however, display as unusable as when the supporting wall is missing.

'''Examples of ramps'''

A simple ramp would look like this:
{{diagram|spaces=yes|\
z +0 z +1
░░░░ ░░░░
═▲o ░▼═
░░░░ ░░░░
o : wall
}}

Carving track corners into ramps is rather unintuitive and complicated. Since engraving tracks always requires two tiles to connect in a straight line as input, you have to give two separate designations for a single job: a track bit from the ramp tile to the "below" direction and another one to the wall of the "upward" direction. If you wanted to change direction on a ramp from east to north:
{{diagram|spaces=yes|\
z +0 z +1
░░░░░ ░░░░░
░░░░░ ══╗░░
=▲░░ ░░▼░░
░░░░░ ░░░░░
}}
you would need to connect the ramp on z +0 both to the west and to the north by issuing two "carve track" commands, one selecting the ramp and the track tile to the west, and another connecting the ramp tile with the wall to the north. An engraver would then carve a NW track corner into the ramp, allowing carts to pass the corner correctly both going up and down. Such track corners are perfectly serviceable for guided carts, but moving down a route of several of them by pushed or ridden cart is problematic - ramps on corners behave very counter-intuitively, resulting in loss of speed when going down and diagonal movement when going up.

Moving to and from ramps (or between ramps "pointing" in different directions0 causes some non-trivial adjustments to speed and even moving along the tiles at a fixed speed ''unrelated to the entry/exit velocity values'', because transitions to/from ramps are processed differently and are not to be "skipped". This affects compact track/ramp combinations (such as e.g. a simple 2x2 ramp spiral) most, and combined with bouncing often makes them work not in the way one could expect. {{cite forum|144328/5705102}}

{{anchor|Tracks}}

=== Hauling route ===
A hauling route is a list of directions describing how and under what conditions a minecart will move. The proper setting up of routes is essential for a working rail system. Routes, stops, departure conditions and stockpile links are managed from the {{k|h}}auling menu.

==== Route ====
A route defines the path a minecart will take along a track, as well as under what conditions it will move or stop moving. A route is made up of stops. Stops are precisely what they sound like, a position on the track at which you want a minecart to stop. A minecart track might use as little as a single stop for a looped track, which will serve as both a starting and stopping point for the cart, or it could contain many stops, perhaps to load supplies or wait for a bridge to be manually lowered, before reaching its destination or returning to its starting point. It is important to note that you only need to place stops on a route where you actually want the cart to stop and wait for some action to occur. They are not needed to help navigate the cart along the track beyond telling it where on the track to stop.

New routes are created with the {{k|h}}auling key. Existing ones can be removed (without confirmation) with the {{k|x}} key, and also {{k|n}}icknamed. Before operating, the route must have a {{k|v}}ehicle assigned to it (this can be done with either the route or a stop selected). Assigning a full minecart to a route may result in a slow hauling job if the contents are heavy.

==== Stops ====
Stops are the individual waypoints that make up a hauling route. A given stop consists of the location of a tile, as well as conditions describing when, where, and how a cart should be moved after being stopped at that tile. Stops can be created from within the {{k|h}}auling menu, by placing the cursor over a tile and hitting {{k|s}} while highlighting the route (or a stop within) you've already designated. A minecart will begin its route at the first stop created, and continue through each subsequent stop, being guided, pushed, or ridden from each stop to the next depending on the conditions specified. In many basic minecart applications, the cart will end up at the same stop it began at, though this is not always the case. It is important to note that hauling stop order is enforced, even if there is no track. A dwarf will drag the cart overland back to a skipped stop in the route's list if your tracks bypass it somehow.

Once a stop has been placed, it is given a default set of conditions under which to move the minecart if it is stopped there. Each new stop gets the same default conditions regardless of the track it is placed upon (e.g. guide the cart to the north). For this reason new stops might get marked by yellow exclamation marks ({{DFtext|!|#ff0}}) due to invalid directions. One important thing to note is that as you place additional stops, the display will show paths between the stops you have defined. However, this is '''not''' necessarily the actual route the minecart will take once the route is in operation. For example, if a route were defined with two stops at opposite ends of a track with many twists and turns, a line will be drawn directly between those stops to show the order in which they will be visited. These route lines may crisscross all over the tracks, but so long as the track is valid end to end, the cart will follow the track from one stop to the next, even across twists, turns, and z-level changes. Stops, which are the steps that make up a route, should not be confused with Track Stops, described below.

===== Stockpile links =====
By placing the cursor on top of a stockpile and using {{k|s}}, you can create stockpile links while defining a hauling stop. Links can also be redefined by selecting them, placing the cursor over a different stockpile, and pressing {{k|p}}. The cart will then be filled by items present in its various linked stockpiles in preference to other items. Note that bins should be used with caution in stockpiles that are linked to minecarts. Bins cause problems when used with the "Desired Items" list in a stop's conditions. For example, if a minecart is set to accept only granite blocks, and to depart north when it is 100% full of granite blocks, it will not depart if any of those granite blocks are in bins, even if bins are also included in the desired items list. Two solutions to this problem exist as of v0.40.24. First, bins can be disallowed in stockpiles that are linked to stops. Alternatively, bins '''can''' be used in conjunction with minecarts provided that the minecart's departure conditions use only "any items" instead of "desired items." This option can be toggled in the advanced conditions menu for a stop, accessible via the {{key|C|}} key. The cart's contents can still be controlled by specifying what items are allowed in the linked stockpile.

===== Departure condition =====
Departure conditions involve setting conditions in which the minecart will leave on the route. Each condition includes:
# A departure mode (Guide, Ride or Push).
# An initial departure direction (NSEW). Note that this defines the initial direction of movement only. Even if a track includes many turns, as long as the initial movement direction is valid the cart will follow the minecart track thereafter.
# A timer, before which the departure condition cannot be met.
# Conditions on the amount of items in the cart.
Departure conditions are created with the {{k|n}} key. A new departure condition will read: "guide north immediately when empty of desired items". This condition can be changed between basic presets with {{k|c}}. "Advanced" mode ({{k|C}}) allows for more precise control over departure conditions: fine tuning the percentage from 0 to 100 in 25% steps ({{k|f}} and {{k|F}}), switching it being either the maximum or the minimum amount of items for the condition to be met ({{k|m}}), and whether the cart accepts all or only a specific set of items ({{k|l}}). Common to both screens are the departure mode ({{k|p}}, Push, Ride or Guide), {{k|d}}irection, and timer ({{k|t}} and {{k|T}}) options.

To have a cart only carry a specific set of items, the stop can be set to only carry "desired" items, opening the selection screen with the {{k|Enter}} key while having said stop condition selected, and toggling as desired, or it can simply be linked to a stockpile and set to depart once it is full of items from its linked stockpiles, regardless of type.

=== Track Stops ===
A Track Stop, not to be confused with a route stop, is an optional, single-tile construction which serves two purposes. First, it can be used to cancel a cart's momentum in order to slow or stop it as it passes over the Track Stop. This might be necessary if a cart were pushed down a series of ramps to its destination. Second, a Track Stop can cause a cart to automatically dump its contents as it passes over the Track Stop. Track Stops are constructed via {{k|b}} {{k|C}} {{k|S}}, and must be constructed atop an existing piece of track. If a Track Stop has been set to automatically dump a cart's contents, the cart will dump its contents in the direction indicated when it passes over the Track Stop. Depending on the friction settings chosen for the Track Stop, the cart might then stop after dumping, or it might continue on its route to another destination.

Track Stops are not mandatory; in fact, their main use is in automated rail systems. However, even in basic rail systems it can be useful to set a Track Stop to dump items: this saves time that dwarves would otherwise spend in removing items from the cart, time that is better spent driving the cart back to where it's needed. Dumping will occur even with a guided cart. '''Take care not to set Track Stops at a loading site to dump their contents''', or dwarves will never be able to fill the cart. It will dump any contents the moment they are loaded.

Counter-intuitive to their construction method, Track Stops are considered [[building]]s and must be removed by {{k|q}} {{k|x}}.
* See [[#More_on_Track_stop |More on Track Stops]]

=== Step-by-step tutorial ===

Let's construct a simple minecart route. This route will move stone blocks from an input stockpile to an output stockpile. We'll begin by creating the stockpiles:

[[File:minecart-example-1.png|Stockpiles designated.]]

The input stockpile is on the left; the output stockpile is on the right. We'll be moving blocks from left to right. Disable bins in both stockpiles, and set the input stockpile to accept only from links. Then make the stockpile take from the mason's workshop where the blocks are being produced.

Next, carve the track:

[[File:minecart-example-2.png|Track carving designation.]]

Note that the ends of the designation are uniquely shaped; this is automatic, and not anything you need to control. Now, wait for your engravers to come along and carve the track into the stone. (Your haulers will probably also fill up the input stockpile while you wait.)

In addition, while we're waiting for that to happen, we'll build an iron minecart in the forge.

[[File:minecart-example-3.png|Track carved.]]

When the track has been carved, it will look like the above (the track will be solid instead of flashing). Now, order a track stop to be constructed next to the output stockpile:

{|
| [[File:minecart-example-4.png|Track stop designation.]]
| [[File:minecart-example-5.png|Select dumping direction.]]
|}

You must press {{k|d}} three times to select the dumping direction ''before'' placing the track stop. We want our blocks to be dumped into the output stockpile east of the track stop. Then wait for a mechanic to come along and build the track stop.

[[File:minecart-example-6.png|Track stop constructed.]]

Now we'll define the actual ''route''. This is done in the {{k|h}}auling menu. Press {{k|r}} to begin defining a route. Next, move the cursor to the input end of the track, and then press {{k|s}} to define the first stop:

{|
| [[File:minecart-example-7.png|Stop 1 designation.]]
| [[File:minecart-example-8.png|Route definition, in progress.]]
|}

Move the cursor again, to the output end of the track, and press {{k|s}} again to define the second stop:

{|
| [[File:minecart-example-9.png|Stop 2 designation.]]
| [[File:minecart-example-10.png|Route definition, two stops.]]
|-
|
| [[File:minecart-example-11.png|Stops are not defined yet.]]
|}

There are several user interface features to note at this point. The stops have been positioned, but they haven't been ''defined'' yet, so there is a warning {{DFtext|!|#ff0}} symbol by each of them. In the lower right corner, we see what the {{DFtext|!|#ff0}} means. Also, note that the second stop is labeled in white, while the other two lines are grey. The white text is a selection indicator, and can be moved up and down by pressing {{k|+}}/{{k|-}}.

Next we need to define what our stops do. We want the minecart to be filled with blocks at the first stop, then travel to the second stop where it will dump its cargo, and then return. Press {{k|-}} to move the selection up to stop 1, and {{k|Enter}} to open it up. By default, the stop has three conditions:

[[File:minecart-example-12.png|Default stop definition.]]

We don't want any of these, so press {{k|x}} three times to delete them. This leaves us with a blank stop. Now we can add the conditions we actually want. Press {{k|n}} to begin adding the first condition, then {{k|d}} twice to change the direction from north to east. Then press {{k|c}} to change the condition from empty to full. This will instruct the minecart to be guided east when full of desired items.

To set the desired items, we create a stockpile link. Press {{k|s}}, then move the cursor to the input stockpile, then press {{k|p}} to select that stockpile. Now press {{k|Enter}}; this opens up a selection screen that resembles the stockpile customization screen. Move down to Blocks, {{k|e}}nable them, then (if you wish) restrict it to stone blocks.

When you've done all that, stop 1 should look like this:

[[File:minecart-example-13.png|Stop 1, defined.]]

Stop 2 is much simpler. All we need to do is have the minecart return to the input stop. So, make a condition and change the direction:

[[File:minecart-example-14.png|Stop 2, defined.]]

Finally, we just have to assign our minecart. Go back to the route definition screen, and press {{k|v}}. Select the minecart, and press {{k|Enter}}.

Now we've got everything set up:

[[File:minecart-example-15.png|Route, fully defined.]]

The V is red because the minecart hasn't been moved onto the track yet. Some dwarf will have to haul it from the forge to the first stop, by hand; this will take a while, especially if the forge is far away.

Once the minecart is in place, dwarves should fill it with blocks from the input stockpile, which will in turn be filled with blocks from the workshop where your mason has been toiling dutifully. When the minecart is full, the blocks will be dumped into the 1x1 stockpile on the right. Automatic quantum dumping!

=== Troubleshooting ===

Because of the complexity of the system, all but the most careful and experienced minecart users will encounter issues. Most route issues can be diagnosed and fixed from the {{k|h}}auling menu.

'''Symptom:''' {{DFtext|! Set dir/connect track|6:1}} message appears to the right of one or more stops

'''Possible Causes:'''
* The departure direction of the stop might be invalid. Edit the stop using {{k|Enter}} and press{{k|d}} until it is pointing in a valid direction.
* The track stop might not be built on top of a track. The track stop must be deconstructed to remedy this issue.
* Your track might not be built correctly. Make sure all connected tracks between destinations are not one-way tracks.
** This can be especially confusing with ramps. To carve a two-way track on a (natural) ramp, you must designate the ramp and one square beyond in the direction you want the track to go.
** Ramps '''must''' have a solid block on the side opposite to the track, or they will neither work nor be marked as "unusable". The solid block can be natural or constructed.
* The desired/kept items might not be configured correctly.

'''Symptom:''' The status '''0% V''' always appears to the right of one stop.

'''Possible Causes:'''
* The stop may not be set to take from a stockpile. Edit the Stop using {{k|Enter}} and make sure you see a message like "Take from Stockpile #1".
* The take conditions must correspond with the contents of the stockpile.
* The track stop may be set to dump. A track stop set to dump cannot be filled. You must either set the stop to a time-based departure or deconstruct the track stop and rebuild it without dumping. (Alternatively, with [[DFHack]] you can modify "Dump on arrival" to "No" using the {{key|q}} menu without rebuilding the stop.)
* Make sure the minecart itself has not been designated to be dumped (such as when using mass-dump).

'''Symptom:''' Dwarves fill the minecart properly, but will not move it thereafter.

'''Possible Causes:'''
* The minecart may contain items which are not included in its current stop's desired items. Check inside the minecart using the {{key|k}} and {{key|z}} keys and ensure that all items in the cart are desired items.
* The minecart may contain desired items in bins. Minecarts seem to have problems realizing that they are in fact full of desired items if some of those items are in bins, even if bins are also among the desired items for that stop. '''This cannot be solved by adding the appropriate bins to the stop's desired items.''' Either disallow bins in stockpiles you intend to load minecarts from, or set the departure conditions to rely only on percentage of total load rather than percentage of desired items using the advanced conditions menu ({{key|C}} key).

'''Symptom:''' Dwarves repeatedly attempt to load the minecart, but no items are ever loaded into it.

'''Possible Causes:'''
* This can be caused by using a Track Stop with autodumping enabled at a loading site. Every time a dwarf places an item into a cart resting on such a track stop, the item will be immediately dumped, causing unlimited, useless cart loading jobs. Autodumping Track Stops should never be used at a loading site.

'''Symptom:''' A dwarf picks up the minecart and carries it to its destination.
* See [[#Quirks|Quirks]]

=== Danger ===
Minecarts are not without <strike>danger</strike> [[fun]]. Although designating a track automatically sets the [[traffic]] designation to low, dwarves ''may'' still walk on them, and [[creature]]s ignore traffic designations altogether. If an unlucky dwarf or creature fails to [[dodger|dodge]] a minecart, they can be injured. Most of this danger can be avoided by setting the minecart {{k|h}}auling commands to guide instead of push or ride (dwarves guiding minecarts will ignore traffic restrictions), as well as by [[pasture|pasturing]] domestic animals and preventing the access of other creatures to the tracks. Note that removing the track doesn't reset that tile back to normal traffic priority, so you may wish to manually clean up traffic designation afterward. Also note that bridges that are used as tracks don't have their traffic priority changed automatically (since they're just normal bridges), which could cause dwarves to pathfind normally through dangerous minecart entrances in your fort's walls if you're not careful.

The only <s>fool</s>''dwarf''-proof method is to make the tracks inaccessible. There are several ways to create a track which works for minecarts but doesn't allow creature-traversal; the simplest is perhaps building a [[statue]] on the tracks. Other options include adding single-tile holes (minecarts moving at reasonable speed will jump the gap), vertical drops, minecart-triggered doors, small pools of liquid (4/7 water or 2/7 magma), and hostile creatures overlooking the tracks. For safety, both ends of the track should be isolated, making the dangerous center sections completely inaccessible (though maintenance access can be provided by a locked door).

Danger does not always involve living victims: careless route designation can also result in minecarts careening off tracks or colliding with each other. If this occurs, the [[item]]s may be scattered; this can cause even more hauling jobs than the minecart aimed to eliminate. Even <s>better</s> worse, scattered items, especially [[weapon]]s, can injure passing [[dwarf|dwarves]] or other [[creature]]s; in the words of Toady One the Great, "Accidental grapeshotting of the dining room should be possible now."

Of course, the danger of using minecarts means they can also be [[Trap_design#Minecarts|used as weapons]] by imaginative players.

== Advanced usage and automation ==
Minecart-specific effects are implemented via track stops, rollers and [[pressure plate]]s with "track" condition set. Since all three are considered [[building]]s, they can't be built on the same square (however convenient track stop + pressure plate would be) nor a simple ramp, and are removed by {{k|q}} {{k|x}}.

=== More on Track stop ===
Track stops are constructions that allow further automation of minecart systems via adjustable features such as braking by friction and automatic dumping of contents. They can be built from logs, bars and blocks through {{K|b}} {{K|C}} {{K|S}}; friction amount, dumping toggle and dumping direction must be set '''before''' construction, and these settings can be neither changed nor seen thereafter; however, track stops can be linked to [[pressure plate]]s or [[lever]]s to toggle friction and dumping On or Off (trigger state is inverted: switch On = track stop Off).

If a [[stockpile]] is placed on the tile that a track stop is set to dump to, it can act as a [[Exploit#Quantum_stockpiles|quantum stockpile]] and any items dumped from a minecart that match the storage settings of the stockpile will remain there and accumulate. Normally trackstops are built on top of existing track to operate on moving minecarts, but they can also be used without tracks to create [[Exploit#The_Minecart_Stop|automatic quantum stockpiles]] (see also [[#Step-by-step_tutorial|step-by-step tutorial]]). It is not always desirable to collect ALL of certain items into one quantum stockpile, such as when distributing a material to multiple separate industries. You can link your quantum stockpile to various other stockpiles, ensuring that your dwarves will keep them supplied as necessary. Because quantum stockpiles never fill up like regular stockpiles, it may be a good idea to add a switch to turn them off.

Items dumped from a minecart at a track stop (or dumped by any other means) into open space fall through z-levels until they land on a solid surface. Items falling onto a designated [[stockpile]] will automatically be considered part of that stockpile, even if the stockpile is set to disallow those items (they will, however, be automatically moved to a more appropriate stockpile, if available). Items falling on top of a minecart will '''not''' fall "inside" the minecart. Use with caution; dwarves have fragile skulls.{{bug|5945}}

=== Automated propulsion ===
==== Roller ====
{{Main|Roller}}

A '''roller''' is a [[power]]ed [[machine component]] for the automated propulsion of minecarts. They are built over the top of existing tracks with {{K|b|M|r}}, requiring a [[mechanic]], ''(length/4)+1'' [[mechanism]]s and a [[rope]]. Rollers may also be placed directly on ramps to help pull carts up Z levels. Rollers are very useful to maintain a cart's momentum along long routes, to get them to climb Z-levels without dwarfpower involved, and to get them to reach speeds unattainable by guiding dwarves. These devices are variable-length (1-10), variable-direction and variable-speed ([[Minecart#Numbers_behind_the_scene|see below]]), all traits that can be set at construction time; a roller uses two units of power per tile it is long.

Single-tile rollers transfer power in all four cardinal directions, while other rollers generally only transfer power perpendicular to their activity direction. Longer rollers can also transfer power along their activity direction if built in the correct order, although this can be hard to accomplish and is easily broken. Rollers cannot be powered from above.

Rollers have great acceleration and capped speed. Carts going faster than the roller are unaffected. If a cart moves across an active roller in the direction the roller works and moves slower than the roller's specified speed, the cart will be set to the roller's speed. A cart going against a roller's movement direction will be sent back the way it came (once again at the roller's speed), unless it was moving extremely fast: speed increment of 100000 allows to reverse carts from the full "highest" (50000) speed roller to full "highest" speed back, but ramps can accelerate a cart beyond this. {{cite forum|144328/5702453}}
A cart crossing over a roller perpendicular to its current movement direction will gain the roller's amount of speed in the perpendicular direction without directly changing its forward motion. Without an adjacent wall to constrict its movement, this will typically send a cart off the rails on a diagonal path, completely unable to follow any tracks until it collides with a wall or is otherwise brought to rest. However, if the roller is placed over a track turn and pushes ''from'' the direction of that turn's track, the turn affects carts ''after'' the roller, so they will be forced into the turn rather than derailed in a diagonal direction. {{cite forum|144328/5702453}}

{{diagram|spaces=yes|\
tracks: full:
║ ║
═╗═ ═╢═
║ ║

╢ : roller pushing from W to E
}}
If the roller is powered, carts from ''all'' directions (unless too fast) exit S, because speed imparted by the roller forces carts toward E and ''then'' into the turn.
If not powered, carts from W and N exit S, carts from E and S exit W. Carts above derail speed will ignore the turn, of course.

{{diagram|spaces=yes|\
║ ║
═╗═ ═╟═
║ ║

╟ : Roller pushing from E to W
}}
Carts from the E or W: exit W.
Carts from N: derailed diagonally, exit SW.
Carts from S: derailed diagonally, exit NW.

Rollers affects carts on a track - if placed on a floor or ramp without any tracks, they are ignored. Depowered rollers are also ignored, friction is determined by the tiles underneath.

Because of their one-way nature, rollers are unsuitable for most two-way minecart tracks (unless you set gears toggling roller A->B off while toggling A<-B rollers on). However, a minecart set to be ''guided'' is not affected by rollers at all{{cite forum|109460/3286235}} — this allows a one-way track to be used in both directions. In addition, unpowered rollers do not affect minecarts.

Care must be taken in [[glacier]]s and other extremely cold [[biome]]s, since rollers (and the machinery used to power them) will not operate when constructed on natural [[ice]] floors.

==== Impulse ramps ====
Carts can be given momentum without rollers or changing z-level through a phenomenon called "impulse ramps". A track ramp which is connected both to a wall and to a floor will ''always'' accelerate a cart towards the connected floor tile, no matter where the cart enters the tile from. This means carts can be accelerated as though dropping z-levels, even if the cart doesn't actually change z-level at all. If a track ramp faces three directions such as ╩, then two of those directions need to be facing walls for the cart to be accelerated towards the remaining direction.

Example of straight impulse acceleration:

{{diagram|spaces=yes|\
▒▒▒▒▒▒▒▒▒▒ ▒▒▒▒▒▒▒▒▒▒
═▲▲▲▲▲▲▲▲▲▲═ ═╚╚╚╚╚╚╚╚╚╚═
▒ : Wall
═ : Normal track
▲/╚ : N/E Track/Ramp
}}

If a cart enters from the left, it will speed up on every track/ramp and exit to the right going very very fast - more than one tile every step. If it enters from the right then it will bounce back impulsed by the ramp if it's going slow enough.

As another oddity, carts coming from ramps will in some cases "teleport" through most of the next tile. This is called the "checkpoint effect", and is explained in detail in the Physics section, below. This negates the deceleration of the next tile if it is a ramp "angled" in a different direction. You can just make an upward spiral alternating impulse ramps and regular upward ramps. It takes no power, is quick and cheap to build, requiring only channeling and track carving, and the cart goes up fast, but not so fast that it launches its contents.

Example of an impulse elevator:

{{diagram|spaces=yes|\
z +0 z +1 z +2 z +3
░░░░░ ░░░░░ ░░░░░ ░░░░░
░╔░░░ ░▼╚╗░ ░░▼▼░ ░░░░░
░╝░░░ ░▼░░░ ░░░╔░ ░░░▼░
░▼▼░░ ░░░░░ ░░░╝░ ░╚╗▼░
░░░░░ ░░░░░ ░░░░░ ░░░░░

░ : Wall
╔,╚,╗,╝ : Track/Ramp
▼ : Down Ramp (empty space)
}}

Note that this impulse elevator, due to the checkpoint effect and upward curved ramp effect, will not actually result in carts traveling straight up the ramp. They will lose speed, bounce off a ramp, then be accelerated back into the spiral after a 9-turn delay on both tiles on the floor where they are stopped. This is because the checkpoint effect allows carts to travel up the ramps in a single turn, but also prevents the impulse ramps from adding acceleration unless the cart is slowed to staying on the ramp for more than one turn. Initial acceleration will carry the cart up a variable number of floors before this effect occurs, but this bouncing back and forth will occur every 5 z-levels after the first time the cart stops. When the cart ''is'' traveling upwards, it will pass every tile at a rate of one tile per turn regardless of its actual speed, due to the checkpoint effect. In tracks with only a single cart, this is negligible, but when multiple carts are on the same track (such as when you place multiple carts on a magma cart lift) this can cause collisions which derail carts or cause other unexpected or undesired behaviors.

The following impulse ramp (while larger) should alleviate these problems by using a straight ramp to go upwards, preceded by an impulse ramp to exploit the checkpoint effect and negate up ramp costs. Corners still decelerate carts, so the cart will tend towards a velocity of 72k, which is derail speed. Derail speed breaks (see Controlling Speed, below) may be necessary at the top.

{{diagram|spaces=yes|\
z +0 z +1 z +2 z +3
░░░░░░ ░░░░░░ ░░░░░░ ░░░░░░
░░░░░░ ░╔╔═░░ ░░▼▼╗░ ░░░░░░
░║░░░░ ░▼░░░░ ░░░░╗░ ░░░░▼░
░╚░░░░ ░▼░░░░ ░░░░║░ ░░░░▼░
░╚▼▼░░ ░░░░░░ ░░░░░░ ░░═╝╝░
░░░░░░ ░░░░░░ ░░░░░░ ░░░░░░

░ : Wall
║,═,╔,╚,╗,╝ : Track/Ramp
▼ : Down Ramp (empty space)
}}

Also, if you want to have a cart following a below-derail speed, the following track works well:
{{diagram|spaces=yes|\
z +0 z +1 z +2 z +3
░░░░░ ░░░░░ ░░░░░ ░░░░░
░░░░░ ░══░░ ░▼▼║░ ░░░▼░
░║░░░ ░▼░░░ ░░░║░ ░░░▼░
░║▼▼░ ░▼░░░ ░░░░░ ░░══░
░░░░░ ░░░░░ ░░░░░ ░░░░░

░ : Wall
║,═ : Track/Ramp
▼ : Down Ramp (empty space)
}}
In this elevator, the cart collides with the walls in the corners, but then realigns on the ramp, picks up speed, checkpoints through the next ramp, and slams into the next wall. It is slower (10 ticks per floor) but produces reliable speeds, and will exit the impulse elevator at little more than push speeds.

A sort of opposite effect to impulse ramps also exists: ramps lacking the proper "up" and "down" connections are treated as flat track, even if they actually go up or down z-levels. This allows building "anti-impulse" slopes consisting entirely of ramps only connected up, which a minecart can travel up forty levels and more, needing no more than a single push.

=== Controlling traffic ===

==== Switching ====

As constructions or tile features, [[door]]s and other furniture can be built on tracks. A [[door]] or [[floodgate]] can be turned on or off by a [[lever]], effectively controlling the flow of automated minecarts. This may be <s>dangerous</s> [[fun]], however.
{{diagram|spaces=yes|\
->
A ════┤≡════ B
┤ : roller pushing to East
≡ : door
}}
The roller pushes the cart east, but until the "departure condition" is fulfilled, the door remains closed and blocks the path.

[[Bridge]]s can also act as tracks, but only if they're lowered or not retracted. This property can enable levers to turn tracks on and off. However, care should be taken to ensure that such bridges are never operated while a cart is on top of them, as the cart will be flung off the track. It's worth noting that it's often faster, and cheaper, to construct large bridges than long sections of constructed track.

A powered track switch can be constructed by building an "inverted" corner as illustrated below.
{{diagram|spaces=yes|\
B B
║ -> ║
║ ║
════╚═══ ════├════
A C A C
├ : roller pushing to West.
}}

If the cart is pushed East from the stop at 'A' while the roller is activated, it will arrive at 'B'. If the roller is not running, it will arrive at 'C'. The switch works by the roller first reversing the incoming cart's movement and the cart ''then'' following the track corner.

This switch is very reliable, reacts instantly to on/off signals, and carts of any speed can be switched by this design, although very fast carts will require rollers that are several tiles long, up to three. The requirement for power can be inconvenient or impractical. Non-powered solutions may use controlled derailment, or a connecting bridge.
{{diagram|spaces=yes|\
B ╥
║
║
╞════╝ ════╡
A D C
}}
Here the track between A and C is not continuous. The only continuous track is A->B, with a corner (not a T section). Fast moving carts will tend to derail at D and rejoin the track to C. Placing a door at D will prevent the derailment, so the cart continues to B. The door is operated by mechanisms elsewhere (typically, a lever, but some fun can be had with pressure plates).

Since it depends on derailing, this switch requires a very fast cart, faster than what can be achieved with rollers alone. To gain sufficient speed, a cart must be accelerated further, usually by descending several levels or through impulse ramps. The high speed makes the cart much more dangerous and harder to control.

If carts are moving too slowly to derail at the corner, a retractable bridge may be used as a connector between A and C.
{{diagram|spaces=yes|\
B╥
║
║
A╞════bbb════╡C
}}
The bridge must overlap the corner. Bridges behave like a track crossing, allowing carts to pass in a straight line. When retracted, the corner reappears, so the carts will continue to B. Bridges take 100 steps to react to a signal, necessitating rather long "lead times" when switching tracks via bridge.

As mentioned above, special care must be taken to make sure the bridge doesn't change state while the cart is passing over it. Retracting bridges will throw the cart, causing it to stop dead. Raising bridges can even crush the cart.

==== Controlling Speed ====


Minecarts can reach extremely high speeds, especially when descending multiple Z-levels. A minecart will derail at a track corner if its speed exceeds 0.5 t/st (tiles per step), '''unless''' the route in the direction of travel is blocked:

Will derail at > 0.5 t/st:

{{diagram|spaces=yes|\
in ══╗ -> derailing
║
out
}}

Will not derail at > 0.5 t/st:
{{diagram|spaces=yes|\
in ══╗O
║
out

O : wall/column.
}}

This behavior can be used to build a "speed limiter", that will ensure that when a minecart exits it is traveling below derail speed:
{{diagram|spaces=yes|\
░░░░ ░░░░░ ░░░░░
in ═╔═╗░ ░╔S╗░ ░╔S╗░
out ═╬═╝░ out ═╗═╝░ out ═╗═╝░
░╚S╝░ ░╚═╝═ in ░╚S╝░
░░░░░ ░░░░ ║░░░
in
░ : wall
S : Track Stop (High Friction or lower)
}}
If the minecart is traveling below derailment speed, it will not be affected; if above, will be slowed down and checked again. Granted, you could do the same just with track turns, but it may take a lot of turns and time.

Since all the derailings, bounces and ramps can impart a sideway component of speed small enough to start visible drift many tiles away (say, [[Fun|in the middle of a bridge]]), track turns have one more use: forcing the carts to move strictly along the grid directions. Carts passing a turn below derailing speed convert one component of velocity into another, thus eliminating the drift.

=== Loading liquids ===
[[Water]] and [[magma]] can also be loaded into minecarts by submerging them to a depth of at least 6/7 while standing still or moving at speeds of at most 10000. Loading fluids onto minecarts can be difficult because the added friction provided by fluids can stop a cart in a submerged tile. Curiously, filling a minecart with magma does not injure a dwarf ''riding'' it. A minecart will hold enough fluid to increase the depth of a single tile by 2. This amount is listed as 833 units, which weigh 459Γ (water) or 999Γ (magma). An iron or steel cart filled with magma weighs 1313Γ, while an adamantine cart filled with magma weighs 1007Γ. Since you need a minecart above the liquid's level, possible arrangements may include pressure-activated sluices, rollers (with magma-safe chains for magma), pouring from above to "submerge" it briefly on the same level and drain excess away (dig deeper and leave a vaporizer, though if you could have power for rollers, may as well use a pump) and exploits with ramps (not necessarily impulse ramps, "same height" passing dip does it).
The liquids can be dumped by a constructed track stop.

== Quirks ==
This little quirk concerns dwarf-managed minecarts. If a track which was previously open becomes blocked (ex. flipping a switch connected to a floodgate you've built on the track to raise it) and the conditions for departure are met, instead of refusing to ride/guide the minecart or ride/guide it until it reaches the obstacle, the dwarf will pick up the minecart off the tracks and haul it to its scheduled destination on foot. If the distance is long enough and the weight of the cart heavy enough (due to being filled with heavy items such as stones), the dwarf may drop the cart because of fatigue/hunger/thirst before reaching the destination. This will cancel that vehicle setting job and make another dwarf come by and attempt to haul the cart to the nearest appropriate stockpile where another dwarf will pick up the cart and attempt to haul it to its initial stop. If the stockpile is far enough from initial stop, this second dwarf who is attempting to place the minecart on its tracks may also drop the minecart out of fatigue/hunger/thirst creating a loop that will go on until a dwarf with enough endurance manages to place the minecart where it belongs.

In fact, it seems dwarves are more than happy to attempt to carry a minecart from one stop to another even if just waiting until the track is open again would be the more sane option.

Dwarves will also carry a minecart to its next stop if the direction specified is incorrect (or invalid). This can often occur when using the default departure settings and forgetting to set the direction of each condition.

Dwarves can admire buildings while riding mine carts. Dwarves will not fall asleep during a ride (at least not from being drowsy). If riding on a continuous powered track loop, the dwarf will die of dehydration/starvation as they can not jump off to get sustenance{{cite forum|109460/3377228}}. Dwarves riding in submerged minecarts will gain experience in [[swimming]].{{cite forum|129889}}

Tracks block wagon access to trade depots, unless they're on a ramp. [[Bridge]]s can also be used, as they function as tracks but do not block wagons.

== Physics ==


Minecart physics depend greatly on the departure mode set in the route stop conditions.

When set to "Push" or "Ride", minecarts will move according to the regular laws of momentum, gaining speed when going downhill, losing it slowly due to friction when on a flat plane, and more quickly when going uphill. In these modes, minecarts will move in a straight line until they either are brought to a stop by friction or an obstacle, or until they encounter a turn. A minecart will roll straight past "blocked" ends of T-junctions or track ends, they have no power to restrict a cart's movement. The cart's behavior is largely independent of the weight of its contents (including fluids and dwarves): heavily loaded carts gain more momentum when accelerating, but this only plays a role in collisions: a heavy cart gains just as much speed and is as easy to stop as a light one. In either case, dwarves can not push nor ride an unpowered cart up a ramp, bouncing back the direction it came. At best, this is a waste of time; at worst, it will give your cart-pushing dwarf a [[fun|fun surprise]]. To solve this, the player can either use Rollers (see below) or set the cart to be Guided.

The difference between "Push" and "Ride" is whether the dwarf will go along with the cart or not.
{{DFtext|Push}}: the dwarf will give the cart an initial push, not enough to go up a ramp, but enough to go some way along flat track, and the dwarf will remain at the first stop, ready for a new job.
{{DFtext|Ride}}: the dwarf will give the cart the same initial push and then hop aboard the cart riding with it to the next stop.
{{DFtext|Guide}}: minecarts seem to ignore all laws of physics. That is:
*Ignore the weight of any and all items inside. Therefore:
**Move at the speed of the dwarf that is guiding them. It is thus recommended to pick the most [[attribute#Agility|agile]] of your dwarves for cart-guiding tasks.
*Ignore working rollers.
*Will ''not'' collide with other guided carts even when a full frontal collision would be expected.
*Will go up ramps like nobody's business.
This is therefore the recommended method of transport for simple non-powered rail systems, despite it diverting a dwarf from other, potentially more important tasks.

Some samples with behavior:
{{diagram|spaces=yes|\
A <-> B A <-> C A <-> B
B B B
║ ║ ║
A══╝ A══╩══C A══╬╗
You can only go A->B ╚╝
Works when the cart Works
is in Guide mode.
}}
In the second example above, a cart "pushed" from B will go over the junction and roll off into the unknown south.

=== Track Direction Irrelevance ===
Carts that are traveling independently, (that is, not guided,) only care that tracks ''are'' on the tile, not which direction the tracks actually move. Tracks respect only curves (with two exits) and ramps.

This means, for example, that the following tracks, when a (non-guided) cart travels from West-to-East, are functionally identical in effect:

{{diagram|spaces=yes|\
A════════════B A╬║╚╔╣╩╦╠╥╨╞╡B
}}

This is because so far as the cart is concerned, only ramps and curves with two exits where the exit in the path they are traveling matters.

Hence, if a minecart encounters the end of the track or a T junction with no "exit" in its movement direction, it will simply leave the track and continue on its course in a straight line until it encounters an obstacle, slows to a stop, or encounters another track even if the tile at which it joins the new track instantly sends it around a corner.

In fact, a "║", a "╦", a "╬", and a "╥" are ''only different in appearance'', and are ignored by the cart, which will continue in its current direction, regardless of the track.

Carts only check for curves when they are halfway through a tile. When they get there, they look to see if their path has no exit. (That is, if it is traveling East, it checks if there is an East exit.) If there is, it ignores all other track directions, and keeps traveling. If there is not, it checks to see if there are only two exits to the track, and if one of those directions was the direction it "came from". (That is, if traveling from the East, it checks if there is a valid exit to the West, and if so, if there is either a North exit or a South exit.) If there is not, it ignores the track anyway, and keeps on traveling as though it were still on track. If there is, it will subtract 1000 from the velocity of the cart, and redirect all forward velocity to the direction of the curve. This change in the direction of velocity ''overwrites'' any "diagonal" velocity, which can prevent diagonal velocity derailments, but any perpendicular velocity is not preserved, and is instead discarded.

=== Valid and Invalid Ramps ===
Ramps are functionally defined for cart purposes as being a tile which exerts an acceleration force upon its "downward slope", and which allows connection to tracks a z-level above or below. This downward slope requires a cart to have one ''and exactly one'' carved exit to the tile that is the "bottom" of the ramp. Ramps accelerate carts in this "downward" direction (possibly leading to diagonal movement, below), and the deceleration of an "uphill" ramp is actually just the acceleration being applied against the direction of a cart's movement.

This is where players can find an exploit in the behavior of ramps - if there are ''two'' "downhill" exits to a ramp (such as a "T junction" on a ramp where only one exit faces a wall), then the ramp provides no acceleration ''or'' deceleration, allowing carts to travel up ramps without any loss of momentum except for the standard "flat track" deceleration, because as far as the cart is concerned, the track ''is'' flat. (A T junction is also not a curve, so the track is considered flat and straight no matter what direction the cart is traveling.)

Similar effects can be achieved when there are ''no'' "downhill" exits to a ramp. This may be the case if you have, for example, an East-West track with a one-tile channel with a ramp in it. The cart will travel through the "dip" with no change in velocity. It can also be the case if you abuse the Track Direction Irrelevance, above, and set only exits ''up'' the ramp, and none leading ''down'' the ramp. For example, if a cart is traveling from West to East up a slope, only carving East exits on each tile of ramp will make the cart travel up the ramp, and then recognize the tile it is on as being a "flat" tile, thus ignoring any deceleration from traveling uphill. Note that this effect only reliably occurs at relatively slow speeds (at around push, or single accelerating ramp speeds) as the cart may simply ignore the ramp and crash into the wall at higher speeds.

=== Falling ===
When falling, a minecart appears to cause no damage upon collision, possibly to allow cart "stacking" across Z-levels.{{cite devlog|2012|04|06}} A dwarf riding in a minecart that is dropped multiple z-levels suffers normal fall damage. Minecarts can fall through up/down stairs.

While airborne, carts do not feel the effects of friction in any horizontal direction, and will continue until they strike an obstacle. Carts that land on tracks instantly re-rail themselves regardless of track directionality.

Falling carts accelerate similarly to the way that a ramp will accelerate a cart in a special z-only velocity that only applies to airborne carts. (Actually, acceleration due to gravity in freefall seems curiously slightly ''slower'' than ramp acceleration.) Ramp acceleration, while it logically should be partially z-directional, is only recorded as x- or y-directional, and there is no translation of z-directional velocity upon landing. Landing carts zero out their vertical velocity upon landing, even when landing on ramps, although carts that had horizontal momentum while falling preserve it.

This means a cart falling (from a hatch, thus with no horizontal speed) onto a track ramp is accelerated as if starting from the middle of the ramp - i.e. to the same speed, no matter how many Z-levels it was dropped, vertical velocity is negated. {{cite forum|144328/5701211}}

Carts falling onto a floor can, however, cause damage to creatures ''one tile below the floor''. This can be used in an [[exploit]] called a "thumper", where carts are caused to repeatedly fall on a floor above an entrance to the fort, inflicting significant damage (as though it were a collision) on those below the cart.

=== Cart Jumps ===
Carts that cross off of "up" ramps relative to their current direction of travel, which do not have a ceiling above them, and do not have valid ramp track before them can translate a portion of their horizontal velocity into vertical velocity, causing a cart to be projected into the air until vertical velocity is negated and overcome by the gravitational acceleration. Because downwards acceleration is applied per-tick, this creates a reasonable facsimile of the parabolic motion of an actual object rolled up a ramp and launched with significant speed.

{{diagram|spaces=yes|\
z0 z0 hiding ramps z+1 A z+1 B (hidden ramp)
▒▒▒▒▒▒▒▒▒▒▒▒ ▒▒▒▒▒▒▒▒▒▒▒▒ ▒▒▒▒▒▒▒▒▒▒▒▒ ▒▒▒▒▒▒▒▒▒▒▒▒
═▲▲▲▲▲══▲▒▲═ ═╚╚╚╚╚═══▒══ ▼▼▼▼▼ ▼═▼ ▼▼▼▼▼ ▼╚▼
▒ : Wall
═ : track
▲ : Ramp
}}
In this diagram, if there is no ceiling above it, the track in z+1 A will launch its carts airborne when they travel across the ramp. z+1 B (with a ramp on the tile on the hill) will not launch the cart. The cart would also not be launched with ''any'' valid ramp, even if it does not travel in an appropriate direction, such as North/South (which the cart will ignore, as it is not a curve, anyway, although it may produce acceleration that may cause diagonal movement.)

Tracks that are travelling at high enough velocity will also start "jumping" from track if it hits an un-tracked tile (flying over and ignoring any tracks) until it is ready to land. Carts that land upon tracked tiles re-rail themselves, and clever designers use this feature to jump over curved track sections in one direction or another. (Retracting bridges over untracked tiles can cause jumps or not cause jumps depending upon the status of the bridge.) Minecart speed must be carefully regulated to ensure reliability of jump length.

This creates a vertical component to acceleration that allows for jumps of around 6 (horizontal) tiles that do not actually leave the z-level the cart is on, but which do apply z-direction velocity on the cart, as per falling.

Carts that approach a downward slope at a high enough velocity will also make a jump, but will not do so if the Checkpoint Effect (below) is exploited through an impulse ramp before the actual downhill as the impulse ramp "tricks" the cart into thinking it has already started going downhill.

=== Skipping ===
If a minecart is moving fast enough, it can skip over [[water]] or [[magma]], making splashes of [[mist]] (or [[magma mist]]) as it attempts to move on them horizontally. This horizontal movement is independent of the minecart and its content's [[weight]].

Skipping causes significant friction on the cart, and even a cart going at max speed from ramps can only make about 50 tiles without requiring re-acceleration. (Carts that decelerate enough that they do not trigger the skipping effect will, of course, sink.)

=== Corner Ramp Derail ===

Corners on upward ramps can cause diagonal movement, forcing a derail even if the cart has a wall next to it, which will force a stop when it touches a wall that forces dwarves to manually reset the cart.

This is caused by the fact that a cart, after turning the bend in the track halfway through the length of the tile, will still "accelerate down", which is now perpendicular to the movement of the cart, causing acceleration to occur in two directions. (Down corner ramps do not have this problem, as when they pass the halfway point, all perpendicular motion is added to forward motion, and after that curve, all downward acceleration is in the forward direction.)

There are two fixes to this problem. One is to simply not put corners on up ramps. The other is to take advantage of the Checkpoint Effect, below, by making a ramp (possibly including an impulse ramp) one tile in front of the ramp to make it skip through most of the tile before sideways momentum can be built.

=== Checkpoint Effect ===
The checkpoint effect, [http://www.bay12forums.com/smf/index.php?topic=144328.0 explained in depth by Larix], is an odd and highly exploitable feature of ramps where minecarts "teleport" through the next tile of track, ignoring nearly all minecart physics (except that they stop at all walls or other obstacles and not only respect curves, but will take them even when they would otherwise derail) and passing through that tile in just a single tick, and into the next tile at the halfway point.

This effect occurs when a cart leaves a downward ramp for any other direction of tile. (This includes ramps which accelerate in different directions, even a ramp which goes from accelerating East to accelerating North due to a bend in a chain of standard down ramps in a curve.) This allows, for example, two valid straight ramps directly next to one another with a cart dropped onto one or the other with no momentum to have the cart pick up acceleration going "down" the ramp as normal, but then flying up through the "up" ramp it travels into with no loss of momentum, as though it had come from an impulse ramp. If the two ramps had at least one space of distance between them, and then a cart were dropped in, the cart would instead "rock" back and forth between the two ramps.

This seems to be because ramps have a slightly longer length than regular tiles - 144,000, rather than 100,000 distance. When this "snaps back" after a ramp, it seems to project the cart suddenly further along the track, making it jump a tile ahead even when otherwise moving at relatively low speeds.

This [[bug]] is the cause of a ''wide array'' of unexpected behavior among people who do not take this bug into account. It causes derailments or failure to climb up seemingly valid impulse elevators. In general, it makes a system that behaves extremely counter-intuitively, and operates ''any time a cart encounters a valid ramp''. At the same time, when its effect is accounted for, it is highly exploitable: It causes "perpetual motion devices" using no power when two opposing ramps are placed next to one another, since the "uphill" effect of the opposing ramp is ignored, preventing deceleration.

Another useful thing to note about this exploit is that carts traveling at no less than 72,000 or so speed (enough to travel half a ramp tile in a single tick) can travel through every tile in just one tick at no change in velocity as long as the tiles alternate between impulse ramp or actual down ramp and any other tile type. The cart checkpoints through the non-down-ramp tiles, and can pass through the (impulse) down ramp tiles in a single tick, before they can actually start gaining momentum.

{{diagram|spaces=yes|\
▒▒▒▒▒▒▒▒▒▒ ▒▒▒▒▒▒▒▒▒▒
═▲═▲═▲═▲═▲═ ═╚═╚═╚═╚═╚═
▒ : Wall
═ : Normal track
▲/╚ : N/E Track/Ramp
}}

If the cart enters from the West at less than 72,000 speed, some of those ramps will cause Eastward acceleration.

This means that an impulse ramp not contiguous to other impulse ramps has a top speed of around 75k:

{{diagram|spaces=yes|\
▒▒▒▒▒ ▒▒▒▒▒
▒╔═╗▒ ▒╔═╗▒
▒╚▲╝▒ ▒╚╗╝▒
▒▒▒▒▒ ▒▒▒▒▒
}}
This setup makes a cart that travels clockwise at a speed that fluctuates around 75k velocity. If the cart has more than 72k velocity, it fails to accelerate in the ramp, as it leaves the ramp in a single turn due to checkpointing to the halfway point. After that, the curves sap 1k velocity, and every tick saps 10 velocity.

Two contiguous impulse ramps with a same-facing "downwards slope", however, do not suffer the checkpoint effect in the second tile, giving functionally triple the space to accelerate. This means it will add velocity (at the standard rate of 4.9k per tick) up to a maximum speed of 216k.
{{diagram|spaces=yes|\
▒▒▒▒▒▒ ▒▒▒▒▒▒
▒╔══╗▒ ▒╔══╗▒
▒╚▲▲╝▒ ▒╚╗╗╝▒
▒▒▒▒▒▒ ▒▒▒▒▒▒
}}
This example results in a cart moving three times as fast as the previous cart.

Three successive ramps results in the highest attainable speeds.

In practical terms, this means that only consecutive ramps should be used for high acceleration, but singleton ramps can be used to have speeds that are somewhat regulated.

=== Stacking ===
If a minecart lands on top of another minecart, they may form a stack, with the upper cart on the z-level above the lower. Subsequent carts do not form a stack, but rather quantum stockpile in the same space. This behaviour is useful for [[megaprojects]] and [[trap design]] with minecarts as the weaponry. Moderation should still be exercised: carts take longer to fall into a "stacking" tile already occupied by other carts and will spend that time "hanging" in the air above the stack. This can lead to following carts striking them, which can cause all kinds of malfunctions. The extra time is two game steps for every cart already in the stack, which doesn't hurt stacks of ten carts very much but makes stacks of 100+ rather impractical.

These minecarts on the upper level generally need to be struck with another minecart to move out, or have their support removed. The latter option is safest done by shooting it away with another minecart, manual removal of a stack-supporting cart typically causes the next cart from the stack to [[fun|fall on top]] of the hauler.

=== Perfectly Elastic Collisions ===
Minecart collisions are perfectly elastic, meaning that not only do minecarts not take damage, but that two carts that are rolling which have frontal collisions of near-similar speed, and where one cart is no more than twice the mass of the other cart, will result in a billiard-ball-like effect of the lighter cart bouncing off the heavier cart with a proportional speed increase dependent upon the relative momentum behind the heavier cart.

Using this trick with carts already at the 270,000 maximum speed from ramps can result in "supersonic" carts traveling at speeds in the millions (travelling a dozen tiles per tick), but where they are suddenly subject to 10,000 units of "terminal velocity" friction per tick. [http://www.bay12forums.com/smf/index.php?topic=137557.0 Thread with SCIENCE here].

While hypothetically capable of launching a minecart into orbit when used in conjunction with a ramp, no cargo can be contained in the launched cart, as the collisions will force ejections of the cargo. Your "unwilling volunteer" [[goblin]] space pioneers will simply become paste underneath the wheels of an extreme high-speed cart.

=== Numbers behind the scene ===

According to early research by '''expwnent'''{{cite forum|112831/3536975}}:

The minecart has a variable for speed. Speed is measured in tiles/100000 ticks, so a speed of one hundred thousand means one tile per tick. By going down a large number of ramps, a maximum speed of 270,000 can be reached, which presents the limit for most practical applications. Short bursts of (much) higher speeds are possible through carefully planned collisions of high-speed carts {{cite forum|137557/5145499}}.

Every tick the cart accumulates distance units, as well as slows down depending on current tile (speed is reduced by "friction" of the tile). The cart will move to the next tile the tick before accumulating 100000 distance units, (or several tiles in case of great speed), then the leftover distance units are added to the default 100000 distance u. of the next tile. Since most deceleration and acceleration is applied per step, with the notable exception of corners, a cart going at twice the speed of another one can cover about four times the distance in a straight line, but only twice the distance along a winding track with very many corners.

A push will teleport a cart to the beginning of the next tile (NOT the middle!) in one tick with 19990 speed (10 speed is lost due to track friction), while a roller will give a cart the roller's set speed, and it will start to accumulate regular track friction past the middle of the roller tile. Some track features will affect a minecart when it is past the middle of the previous tile: entering a ramp or a hole/drop will happen when the cart has left the middle of the previous tile, and the ramp will gain additional distance unit depending on the leftover units from the previous tile. When a cart leaves a ramp it will emerge after one tick in the middle of the next regular tile, so its entry coordinate is "50000-speed+friction". Rollers also affect the speed of minecart from the middle of the previous tile.

Friction of tiles:
{| class="wikitable"
|-
! Tile
! Friction
! Comment
|-
| Tracks
| 10
|-
| Ground/Floor
| 200
|-
| Unusable ramp
| 10
|-
| Upwards ramp
| 4910 (10+4900)
|-
| Downwards ramp
| -4890 (10-4900)
|-
| Roller
| ±100000 (but capped by the set speed)
|-
| Corner track
| 10
| Speed reduced by 1000 upon leaving the corner tile
|-
| Track stop (highest)
| 50000
|-
| Track stop (high)
| 10000
|-
| Track stop (medium)
| 500
|-
| Track stop (low)
| 50
|-
| Track stop (lowest)
| 10
|-
| Water 1-6
| Additional (WaterLevel - 1) * 100
| rowspan="2" | [[#Skipping|See Skipping]]
|-
| Magma 1-6
| Additional (WaterLevel - 1) * 500
|-
| Empty space
| 0
|}

Water of depth 7/7 provides a friction of about 10000 per step, as does maximum-depth magma. This higher friction may not apply to very slow-moving carts.

Impulse sources:
{| class="wikitable"
|-
! Feature
! Speed
|-
| Push
| 20000
|-
| Roller lowest
| 10000
|-
| Roller low
| 20000
|-
| Roller medium
| 30000
|-
| Roller high
| 40000
|-
| Roller Highest
| 50000
|-
|}

== Non-standard uses ==
Minecarts include some interesting characteristics that have motivated uses beyond hauling. They can be useful for creating fully-automated [[exploit|quantum stockpiles]] and [[garbage disposal]]s. Storing perishable goods (meat, meals, etc.) inside a minecart appears to guard against rot and vermin.
Minecarts can be [[Trap_design#Minecarts|used as weapons]], or as (hopefully non-fatal) triggers to restart stalled [[healthcare]]. They can also be used to time/control game events, either using a basic [[repeater]] or much more advanced [[minecart logic]].
Minecarts trigger [[pressure plate]]s, which means a trap can be designed to trigger when a thief attempts to steal a minecart.
A pressure plate can be used as automatic and more precise custom "launch when full enough" system - as long as weight of your minecarts stays the same. You cannot build a hatch or roller on the same tile, so launch by bumping with another cart. {{cite forum|15096/4580050}}
Dwarves riding minecarts can attack enemies within reach (which goes back to dev log). This applies to shooting, and they actually can hit targets while riding by.{{cite forum|109460/5266119}} Whether a minecart protects the rider and how it interacts with dodging is not known yet. Minecart riders can also [[Swimming#Minecart_training|train swimming]] and [[Megaprojects#Surveillance_Track|detect ambushers]].

== Adventure mode ==
In addition to being used for hauling, minecarts can also be ridden in [[adventure mode]]. (Adapted from forum thread {{cite forum|122903/4258212}})

# If the minecart is in your inventory, drop it. If it is already on the ground, proceed to step 2.
# Press {{k|u}} when you are 1 tile away from the minecart (or standing on the same tile as the minecart).
# You will be presented with the following options:
[[File:minecart adventure mode menu.png|left]]
{{clear}}
* If you {{DFtext|Push}} the minecart, it will move a few tiles in the direction you chose. Physics comes into play here, so it will gain/lose speed depending on the usual factors.
* If you {{DFtext|Ride}} the minecart, you will hop into the minecart, even if you were a tile away, and it will move in the chosen direction with you in it. It will gain/lose speed depending on the usual factors. Whilst the minecart is in motion, you should press {{k|.}} to skip your turn; if you attempt to move whilst the minecart is still in motion, the laws of physics come into play, and you will take [[wound|damage]]. Alternatively, you can push the minecart whilst it's still in motion (although it's unclear how one can bend [[physics]] so as to push a moving minecart whilst inside the minecart). If you push it in the same direction you are already travelling in, you will greatly increase the minecart's velocity. You can also push it in different directions, and this will cause it to gradually change direction-the amount of pushes this requires depends on the minecart's velocity. Once the minecart has stopped moving, you may move out of it safely, or you may want to give it another push. Note that if you push a minecart right after having ridden it (still on the same tile as the minecart), it will act as though you chose to ''ride'' it.

If you want to test this out without creating an adventurer, the [[object testing arena]] allows you to spawn minecarts ({{k|k}}-{{k|c}}-{{k|n}})

== Forging and Melting ==
* Metal minecarts cost '''two''' [[metal]] bars to forge, or '''six''' [[adamantine]] wafers.
* When a non-adamantine metal minecart is melted down, it will return '''1.8''' metal bars, for an '''efficiency of 90%'''.
* When an adamantine minecart is melted down, it will produce '''1.8''' wafers, for an '''efficiency of 30%'''.

== See also ==
* [http://www.bay12forums.com/smf/index.php?topic=109460.0 The "How Does Minecart" Thread] by '''Girlinhat''' et al.
* [http://www.bay12forums.com/smf/index.php?topic=112831.0 SCIENCE: Quantifying minecart physics] by '''Snaake''' et al.
* [http://www.bay12forums.com/smf/index.php?topic=129676.0 How to build a Multi-cart Ore to Magma Minecart Project without needing power] by '''WanderingKid'''.
* [http://www.bay12forums.com/smf/index.php?topic=144328.0 My very own Minecart Education Thread. Ten Lessons, now complete.] by '''Larix'''.

== Bugs ==
*A dwarf will drop her [[child|baby]], if she has one, when boarding a minecart set to be ridden.
*Dwarves have no concept of traffic safety and will walk into busy minecart lines to retrieve objects, often with deadly consequences. This is especially problematic in [[Swimming#Minecart_training|clever applications]] depending on dwarves riding the carts very frequently, because they have a bad habit of dumping their worn clothes on the tracks after a minecart ride. Adding an automatically-operated [[hatch cover]] at the end of such a ride can help prevent [[unfortunate accident]]s.
*Dwarves cannot guide a minecart through an unlocked door unless another dwarf opens the door.{{bug|6056}}
*It is possible for a creature and minecart moving towards each other to pass without collision if they exchange tiles in the same tick.
*After a minecart ride, a dwarf will sometimes haul the minecart to a storage stockpile, leaving another dwarf to haul the vehicle back to the route.
*Minecarts falling onto a floor injure creatures in the tile below the floor.{{bug|6068}}
*A minecart's initial velocity is not affected by weight, when pushed or launched from rollers.{{bug|6296}}
*Removing a stop that has a vehicle waiting on it may cause the game to crash.{{bug|5980}}

{{Category|Fortress mode}}
{{Category|Interface}}

[[ru:Minecart]]

Minecart

2015-06-18T20:06:18Z

NW Kohaku: /* Impulse ramps */

{{Quality|Masterwork|08:15, 19 May 2015 (UTC)}}
{{av}}
A '''minecart''' is a [[tool]] intended for [[hauling]], introduced in version 0.34.08. It can be made of [[wood]] at a [[carpenter's workshop]] or [[metal]] at a [[metalsmith's forge]] (using the [[Metal crafter|metalcrafting]] labor.) Minecarts store up to five times as many items as [[wheelbarrow]]s and are quite a bit faster than dwarves hauling objects by hand, but have the disadvantages of requiring a dedicated track network, a complex route planning phase, and the possibility of dwarves [[Fun|blundering into the path of carts filled with lead ore]]. Tracks may be carved into stone, or [[Construction|constructed]]; the latter allows above-ground routes, but these are more difficult to set up due to their additional [[building material|material requirements]].

Just like wheelbarrows, minecarts are considered [[item]]s and are stored in a [[furniture]] [[stockpile]]. Despite their five-times-greater capacity, they are only 33% larger than wheelbarrows and are identical in base [[item value|value]] when made from the same [[material]] (the value may differ due to the [[item quality]]). [[thief|Thieves]] or even mischievous animals can steal minecarts, even when they are moving on a track{{cite forum|109460/3289070}}. However, minecarts moving fast enough or being ridden cannot be stolen.

Although most of the utility of minecarts is in [[fortress mode]], an [[adventure mode|adventurer]] can also ride in a minecart. Adventurers can also pick up and relocate minecarts.

The invention of minecarts revolutionized the [[minecart logic|Science of Dwarfputing]] by enabling smaller, faster logic systems to be built.

== Basic Minecart Usage ==
Minecarts can be used to swiftly transport dwarves, [[flow|fluids]], and/or large amounts of items, but before you have a functional minecart there are several preconditions that need to be met. First of all you need an actual minecart, constructed either in a [[carpenter's workshop]] or [[metalsmith's forge]]. For the minecart to be able to move you also need to carve (with {{k|d}} {{k|T}}) or construct (with {{k|b}} {{k|C}} {{k|T}}) a track, which could be as simple as a straight line. Finally you need to construct stops on your track (with {{k|b}} {{k|C}} {{k|S}}) where the minecart will start and stop.

After you have created the stops and assigned a cart to the track, you must create logic routes connecting several stops and designate starting conditions for each stop. This is done with the {{k|h}}auling key. The most basic conditions are how the cart's movement is initiated and in which direction the cart should start moving. Carts can be either be Pushed (a dwarf stands at a stop and gives the cart a single push) or Guided (a dwarf continually pushes the cart forward, guiding it along the track). The [[hauling]] [[labor]] required for pushing and guiding carts is called "Push/Haul Vehicles" and is turned on by default.

To control which items to transport you can add conditions specifying: (1) which kind of items to be loaded, and unloaded, (2) stockpile links to define which stockpile(s) the items should be un/loaded to and from.

===Capacity and weights ===
Minecarts have five times the [[Weight|capacity]] of [[wheelbarrow]]s.

'''Examples of the capacity of one cart'''
{| class="wikitable"
|-
! Item
! Amount
|-
| [[stone]]
| 5
|-
| [[wood|log]]
| 10
|-
| [[block]]/[[bar]]
| 83
|-
| [[Kitchen|prepared meals]]
| 500
|-
| [[Trap_component#Spiked_ball|spiked balls]]
| 500
|-
| [[Weapon#Native_weapons|mace]]
| 625
|-
| [[Weapon#Native_weapons|spears]]
| 1250
|-
| [[cloth]]
| 2500
|}

The weight of the loaded minecart does not affect the initial velocity received from pushing or launching from a roller. However, the load of a minecart ''does'' affect whether a [[pressure plate]] triggers or not, based on the pressure plate's setting.

'''Weights of different carts'''

{| class="wikitable"
|-
! Type of cart
! Empty cart
! Fully loaded (items)
|-
| oaken minecart
| 28Γ
| 378Γ (10 oak logs)
|-
| platinum minecart
| 856Γ
| 10482Γ (83 gold bars)
|}

The weight of a minecart is one twenty-fifth (1/25) the [[density]] of its material in Urists. Because pressure plates can be set to trigger at intervals of 50 Urists, minecarts with weights just under a multiple of 50 are ideal for switching based on whether they're full or empty. The best minecart materials for full/empty switching are as follows:

{| class="wikitable sortable"
|-
! Material !! Minecart weight !! Content weight required to trigger !! Banana roasts required to trigger (for scale)
|-
| [[Bismuth]] (moods only) || 391 || 9 || 15
|-
| [[Brass]] || 342 || 8 || 14
|-
| [[Electrum]] || 596 || 4 || 7
|-
| [[Fine pewter]] || 291 || 9 || 15
|-
| [[Glumprong]] || 48 || 2 || 4
|-
| [[Lay pewter]] || 291 || 9 || 15
|-
| [[Nickel silver]] || 346 || 4 || 7
|-
| [[Tin]] || 291 || 9 || 15
|-
| [[Trifle pewter]] || 291 || 9 || 15
|}

=== Creating tracks ===
Minecart tracks are made up of contiguous track, tracked ramp, or bridge tiles. Track tiles and tracked ramp tiles have a direction or series of directions associated with them. These directions dictate which directions a minecart on a given tile may move from that tile. For example, a Track NE (northeast) tile allows a minecart on it to move either north or east from its present position. Therefore, if you want your minecart to move east along a straight piece of track, then return west using that same track, you would need to use EW tracks so that the cart could travel east initially, then return west over the same track. Excluding designs in which the cart will "jump" tracks via a drop or other ramp, tracks must be valid end to end to work for most looped or straight-track applications. A single east only track tile in your line of east-west tracks will cause any route using the track to fail the moment it tries to go the wrong way over that tile. Minecart tracks can be built in two ways: Engraved/carved or constructed. A given minecart track need not use engraved or constructed elements exclusively, as the two methods can be used interchangeably depending on the needs of a given section of track. The way the tracks are built is slightly different between the two, as explained below.

====Simple tracks====

'''Carved'''

A single-tile wide strip of natural stone can be designated to be [[Engraver|carved]] (with {{K|d}} {{k|T}}), which will create a straight two-way track. The creation of corners, crossings, and T-junctions is as simple as designating another strip of track that overlaps an existent or newly designated track. Engraved tracks are removed by [[smoothing]] the rock they're on, which results in a smooth floor (that can be re-engraved if necessary), or by building a [[floor]] on top and subsequently removing it. Dwarves can carve corner tracks in one pass by designating the track carving twice and canceling unwanted carvings (with {{K|d}} {{K|x}}). Tracks can be engraved in any natural floor tile, rough, smooth and even over engravings, providing an easy method to remove low-quality or undesired floor engravings. Once a track has been engraved, it's important to check the track directions for each tile in the route carefully to make sure no mistakes were made by yourself or the game's track engraving logic.

'''Constructed'''

Tracks can also be built as regular [[construction]]s (through {{K|b}} {{K|C}} {{K|T}}). This method is resource-expensive, since each track tile requires one stone, [[bar]], or [[block]] for construction, and time-consuming, since you can't designate strips longer than 10 tiles at a time. Corners, crossings, T-junctions, and ramps also have to be designated individually. However, it is usually the only way to build tracks above ground or on soil (barring the [[Obsidian farming|creation of obsidian]]). Constructed tracks are designated for removal like any regular construction; be aware that removing track ramps built on top of natural ones will also remove the original ramp, leaving a flat floor.

====Ramps====

'''Carved'''

The carving of natural ramps is a little more confusing: to carve a two-way track on a ramp (natural only, does not work on constructed ramps), you must designate the track '''starting on the ramp and one square beyond''' in the direction you want the track to go. For the side of the ramp square you want to head upward, there '''must''' be either a natural or constructed wall in the square next to it, otherwise the game assumes you are trying to carve it on the same level -- this can result in the track being carved underneath a door or other object. If you have accidentally done this, you can correct it by smoothing the ramp and constructing a single square of wall next to it, then re-carving the ramp correctly. (However, the wall must stay there permanently; removing it will disconnect the track.)

'''Constructed'''

When constructing track ramps, the stated direction should be the same as the connected tracks. For example, a track going up from West to East would require, starting from the West, a Track (EW), a Track/Ramp (EW) and a Wall behind the ramp, underneath the section of track above it. Incorrectly placed ramps result in minecarts ignoring the ramp and crashing into the supporting wall. They will not, however, display as unusable as when the supporting wall is missing.

'''Examples of ramps'''

A simple ramp would look like this:
{{diagram|spaces=yes|\
z +0 z +1
░░░░ ░░░░
═▲o ░▼═
░░░░ ░░░░
o : wall
}}

Carving track corners into ramps is rather unintuitive and complicated. Since engraving tracks always requires two tiles to connect in a straight line as input, you have to give two separate designations for a single job: a track bit from the ramp tile to the "below" direction and another one to the wall of the "upward" direction. If you wanted to change direction on a ramp from east to north:
{{diagram|spaces=yes|\
z +0 z +1
░░░░░ ░░░░░
░░░░░ ══╗░░
=▲░░ ░░▼░░
░░░░░ ░░░░░
}}
you would need to connect the ramp on z +0 both to the west and to the north by issuing two "carve track" commands, one selecting the ramp and the track tile to the west, and another connecting the ramp tile with the wall to the north. An engraver would then carve a NW track corner into the ramp, allowing carts to pass the corner correctly both going up and down. Such track corners are perfectly serviceable for guided carts, but moving down a route of several of them by pushed or ridden cart is problematic - ramps on corners behave very counter-intuitively, resulting in loss of speed when going down and diagonal movement when going up.

Moving to and from ramps (or between ramps "pointing" in different directions0 causes some non-trivial adjustments to speed and even moving along the tiles at a fixed speed ''unrelated to the entry/exit velocity values'', because transitions to/from ramps are processed differently and are not to be "skipped". This affects compact track/ramp combinations (such as e.g. a simple 2x2 ramp spiral) most, and combined with bouncing often makes them work not in the way one could expect. {{cite forum|144328/5705102}}

{{anchor|Tracks}}

=== Hauling route ===
A hauling route is a list of directions describing how and under what conditions a minecart will move. The proper setting up of routes is essential for a working rail system. Routes, stops, departure conditions and stockpile links are managed from the {{k|h}}auling menu.

==== Route ====
A route defines the path a minecart will take along a track, as well as under what conditions it will move or stop moving. A route is made up of stops. Stops are precisely what they sound like, a position on the track at which you want a minecart to stop. A minecart track might use as little as a single stop for a looped track, which will serve as both a starting and stopping point for the cart, or it could contain many stops, perhaps to load supplies or wait for a bridge to be manually lowered, before reaching its destination or returning to its starting point. It is important to note that you only need to place stops on a route where you actually want the cart to stop and wait for some action to occur. They are not needed to help navigate the cart along the track beyond telling it where on the track to stop.

New routes are created with the {{k|h}}auling key. Existing ones can be removed (without confirmation) with the {{k|x}} key, and also {{k|n}}icknamed. Before operating, the route must have a {{k|v}}ehicle assigned to it (this can be done with either the route or a stop selected). Assigning a full minecart to a route may result in a slow hauling job if the contents are heavy.

==== Stops ====
Stops are the individual waypoints that make up a hauling route. A given stop consists of the location of a tile, as well as conditions describing when, where, and how a cart should be moved after being stopped at that tile. Stops can be created from within the {{k|h}}auling menu, by placing the cursor over a tile and hitting {{k|s}} while highlighting the route (or a stop within) you've already designated. A minecart will begin its route at the first stop created, and continue through each subsequent stop, being guided, pushed, or ridden from each stop to the next depending on the conditions specified. In many basic minecart applications, the cart will end up at the same stop it began at, though this is not always the case. It is important to note that hauling stop order is enforced, even if there is no track. A dwarf will drag the cart overland back to a skipped stop in the route's list if your tracks bypass it somehow.

Once a stop has been placed, it is given a default set of conditions under which to move the minecart if it is stopped there. Each new stop gets the same default conditions regardless of the track it is placed upon (e.g. guide the cart to the north). For this reason new stops might get marked by yellow exclamation marks ({{DFtext|!|#ff0}}) due to invalid directions. One important thing to note is that as you place additional stops, the display will show paths between the stops you have defined. However, this is '''not''' necessarily the actual route the minecart will take once the route is in operation. For example, if a route were defined with two stops at opposite ends of a track with many twists and turns, a line will be drawn directly between those stops to show the order in which they will be visited. These route lines may crisscross all over the tracks, but so long as the track is valid end to end, the cart will follow the track from one stop to the next, even across twists, turns, and z-level changes. Stops, which are the steps that make up a route, should not be confused with Track Stops, described below.

===== Stockpile links =====
By placing the cursor on top of a stockpile and using {{k|s}}, you can create stockpile links while defining a hauling stop. Links can also be redefined by selecting them, placing the cursor over a different stockpile, and pressing {{k|p}}. The cart will then be filled by items present in its various linked stockpiles in preference to other items. Note that bins should be used with caution in stockpiles that are linked to minecarts. Bins cause problems when used with the "Desired Items" list in a stop's conditions. For example, if a minecart is set to accept only granite blocks, and to depart north when it is 100% full of granite blocks, it will not depart if any of those granite blocks are in bins, even if bins are also included in the desired items list. Two solutions to this problem exist as of v0.40.24. First, bins can be disallowed in stockpiles that are linked to stops. Alternatively, bins '''can''' be used in conjunction with minecarts provided that the minecart's departure conditions use only "any items" instead of "desired items." This option can be toggled in the advanced conditions menu for a stop, accessible via the {{key|C|}} key. The cart's contents can still be controlled by specifying what items are allowed in the linked stockpile.

===== Departure condition =====
Departure conditions involve setting conditions in which the minecart will leave on the route. Each condition includes:
# A departure mode (Guide, Ride or Push).
# An initial departure direction (NSEW). Note that this defines the initial direction of movement only. Even if a track includes many turns, as long as the initial movement direction is valid the cart will follow the minecart track thereafter.
# A timer, before which the departure condition cannot be met.
# Conditions on the amount of items in the cart.
Departure conditions are created with the {{k|n}} key. A new departure condition will read: "guide north immediately when empty of desired items". This condition can be changed between basic presets with {{k|c}}. "Advanced" mode ({{k|C}}) allows for more precise control over departure conditions: fine tuning the percentage from 0 to 100 in 25% steps ({{k|f}} and {{k|F}}), switching it being either the maximum or the minimum amount of items for the condition to be met ({{k|m}}), and whether the cart accepts all or only a specific set of items ({{k|l}}). Common to both screens are the departure mode ({{k|p}}, Push, Ride or Guide), {{k|d}}irection, and timer ({{k|t}} and {{k|T}}) options.

To have a cart only carry a specific set of items, the stop can be set to only carry "desired" items, opening the selection screen with the {{k|Enter}} key while having said stop condition selected, and toggling as desired, or it can simply be linked to a stockpile and set to depart once it is full of items from its linked stockpiles, regardless of type.

=== Track Stops ===
A Track Stop, not to be confused with a route stop, is an optional, single-tile construction which serves two purposes. First, it can be used to cancel a cart's momentum in order to slow or stop it as it passes over the Track Stop. This might be necessary if a cart were pushed down a series of ramps to its destination. Second, a Track Stop can cause a cart to automatically dump its contents as it passes over the Track Stop. Track Stops are constructed via {{k|b}} {{k|C}} {{k|S}}, and must be constructed atop an existing piece of track. If a Track Stop has been set to automatically dump a cart's contents, the cart will dump its contents in the direction indicated when it passes over the Track Stop. Depending on the friction settings chosen for the Track Stop, the cart might then stop after dumping, or it might continue on its route to another destination.

Track Stops are not mandatory; in fact, their main use is in automated rail systems. However, even in basic rail systems it can be useful to set a Track Stop to dump items: this saves time that dwarves would otherwise spend in removing items from the cart, time that is better spent driving the cart back to where it's needed. Dumping will occur even with a guided cart. '''Take care not to set Track Stops at a loading site to dump their contents''', or dwarves will never be able to fill the cart. It will dump any contents the moment they are loaded.

Counter-intuitive to their construction method, Track Stops are considered [[building]]s and must be removed by {{k|q}} {{k|x}}.
* See [[#More_on_Track_stop |More on Track Stops]]

=== Step-by-step tutorial ===

Let's construct a simple minecart route. This route will move stone blocks from an input stockpile to an output stockpile. We'll begin by creating the stockpiles:

[[File:minecart-example-1.png|Stockpiles designated.]]

The input stockpile is on the left; the output stockpile is on the right. We'll be moving blocks from left to right. Disable bins in both stockpiles, and set the input stockpile to accept only from links. Then make the stockpile take from the mason's workshop where the blocks are being produced.

Next, carve the track:

[[File:minecart-example-2.png|Track carving designation.]]

Note that the ends of the designation are uniquely shaped; this is automatic, and not anything you need to control. Now, wait for your engravers to come along and carve the track into the stone. (Your haulers will probably also fill up the input stockpile while you wait.)

In addition, while we're waiting for that to happen, we'll build an iron minecart in the forge.

[[File:minecart-example-3.png|Track carved.]]

When the track has been carved, it will look like the above (the track will be solid instead of flashing). Now, order a track stop to be constructed next to the output stockpile:

{|
| [[File:minecart-example-4.png|Track stop designation.]]
| [[File:minecart-example-5.png|Select dumping direction.]]
|}

You must press {{k|d}} three times to select the dumping direction ''before'' placing the track stop. We want our blocks to be dumped into the output stockpile east of the track stop. Then wait for a mechanic to come along and build the track stop.

[[File:minecart-example-6.png|Track stop constructed.]]

Now we'll define the actual ''route''. This is done in the {{k|h}}auling menu. Press {{k|r}} to begin defining a route. Next, move the cursor to the input end of the track, and then press {{k|s}} to define the first stop:

{|
| [[File:minecart-example-7.png|Stop 1 designation.]]
| [[File:minecart-example-8.png|Route definition, in progress.]]
|}

Move the cursor again, to the output end of the track, and press {{k|s}} again to define the second stop:

{|
| [[File:minecart-example-9.png|Stop 2 designation.]]
| [[File:minecart-example-10.png|Route definition, two stops.]]
|-
|
| [[File:minecart-example-11.png|Stops are not defined yet.]]
|}

There are several user interface features to note at this point. The stops have been positioned, but they haven't been ''defined'' yet, so there is a warning {{DFtext|!|#ff0}} symbol by each of them. In the lower right corner, we see what the {{DFtext|!|#ff0}} means. Also, note that the second stop is labeled in white, while the other two lines are grey. The white text is a selection indicator, and can be moved up and down by pressing {{k|+}}/{{k|-}}.

Next we need to define what our stops do. We want the minecart to be filled with blocks at the first stop, then travel to the second stop where it will dump its cargo, and then return. Press {{k|-}} to move the selection up to stop 1, and {{k|Enter}} to open it up. By default, the stop has three conditions:

[[File:minecart-example-12.png|Default stop definition.]]

We don't want any of these, so press {{k|x}} three times to delete them. This leaves us with a blank stop. Now we can add the conditions we actually want. Press {{k|n}} to begin adding the first condition, then {{k|d}} twice to change the direction from north to east. Then press {{k|c}} to change the condition from empty to full. This will instruct the minecart to be guided east when full of desired items.

To set the desired items, we create a stockpile link. Press {{k|s}}, then move the cursor to the input stockpile, then press {{k|p}} to select that stockpile. Now press {{k|Enter}}; this opens up a selection screen that resembles the stockpile customization screen. Move down to Blocks, {{k|e}}nable them, then (if you wish) restrict it to stone blocks.

When you've done all that, stop 1 should look like this:

[[File:minecart-example-13.png|Stop 1, defined.]]

Stop 2 is much simpler. All we need to do is have the minecart return to the input stop. So, make a condition and change the direction:

[[File:minecart-example-14.png|Stop 2, defined.]]

Finally, we just have to assign our minecart. Go back to the route definition screen, and press {{k|v}}. Select the minecart, and press {{k|Enter}}.

Now we've got everything set up:

[[File:minecart-example-15.png|Route, fully defined.]]

The V is red because the minecart hasn't been moved onto the track yet. Some dwarf will have to haul it from the forge to the first stop, by hand; this will take a while, especially if the forge is far away.

Once the minecart is in place, dwarves should fill it with blocks from the input stockpile, which will in turn be filled with blocks from the workshop where your mason has been toiling dutifully. When the minecart is full, the blocks will be dumped into the 1x1 stockpile on the right. Automatic quantum dumping!

=== Troubleshooting ===

Because of the complexity of the system, all but the most careful and experienced minecart users will encounter issues. Most route issues can be diagnosed and fixed from the {{k|h}}auling menu.

'''Symptom:''' {{DFtext|! Set dir/connect track|6:1}} message appears to the right of one or more stops

'''Possible Causes:'''
* The departure direction of the stop might be invalid. Edit the stop using {{k|Enter}} and press{{k|d}} until it is pointing in a valid direction.
* The track stop might not be built on top of a track. The track stop must be deconstructed to remedy this issue.
* Your track might not be built correctly. Make sure all connected tracks between destinations are not one-way tracks.
** This can be especially confusing with ramps. To carve a two-way track on a (natural) ramp, you must designate the ramp and one square beyond in the direction you want the track to go.
** Ramps '''must''' have a solid block on the side opposite to the track, or they will neither work nor be marked as "unusable". The solid block can be natural or constructed.
* The desired/kept items might not be configured correctly.

'''Symptom:''' The status '''0% V''' always appears to the right of one stop.

'''Possible Causes:'''
* The stop may not be set to take from a stockpile. Edit the Stop using {{k|Enter}} and make sure you see a message like "Take from Stockpile #1".
* The take conditions must correspond with the contents of the stockpile.
* The track stop may be set to dump. A track stop set to dump cannot be filled. You must either set the stop to a time-based departure or deconstruct the track stop and rebuild it without dumping. (Alternatively, with [[DFHack]] you can modify "Dump on arrival" to "No" using the {{key|q}} menu without rebuilding the stop.)
* Make sure the minecart itself has not been designated to be dumped (such as when using mass-dump).

'''Symptom:''' Dwarves fill the minecart properly, but will not move it thereafter.

'''Possible Causes:'''
* The minecart may contain items which are not included in its current stop's desired items. Check inside the minecart using the {{key|k}} and {{key|z}} keys and ensure that all items in the cart are desired items.
* The minecart may contain desired items in bins. Minecarts seem to have problems realizing that they are in fact full of desired items if some of those items are in bins, even if bins are also among the desired items for that stop. '''This cannot be solved by adding the appropriate bins to the stop's desired items.''' Either disallow bins in stockpiles you intend to load minecarts from, or set the departure conditions to rely only on percentage of total load rather than percentage of desired items using the advanced conditions menu ({{key|C}} key).

'''Symptom:''' Dwarves repeatedly attempt to load the minecart, but no items are ever loaded into it.

'''Possible Causes:'''
* This can be caused by using a Track Stop with autodumping enabled at a loading site. Every time a dwarf places an item into a cart resting on such a track stop, the item will be immediately dumped, causing unlimited, useless cart loading jobs. Autodumping Track Stops should never be used at a loading site.

'''Symptom:''' A dwarf picks up the minecart and carries it to its destination.
* See [[#Quirks|Quirks]]

=== Danger ===
Minecarts are not without <strike>danger</strike> [[fun]]. Although designating a track automatically sets the [[traffic]] designation to low, dwarves ''may'' still walk on them, and [[creature]]s ignore traffic designations altogether. If an unlucky dwarf or creature fails to [[dodger|dodge]] a minecart, they can be injured. Most of this danger can be avoided by setting the minecart {{k|h}}auling commands to guide instead of push or ride (dwarves guiding minecarts will ignore traffic restrictions), as well as by [[pasture|pasturing]] domestic animals and preventing the access of other creatures to the tracks. Note that removing the track doesn't reset that tile back to normal traffic priority, so you may wish to manually clean up traffic designation afterward. Also note that bridges that are used as tracks don't have their traffic priority changed automatically (since they're just normal bridges), which could cause dwarves to pathfind normally through dangerous minecart entrances in your fort's walls if you're not careful.

The only <s>fool</s>''dwarf''-proof method is to make the tracks inaccessible. There are several ways to create a track which works for minecarts but doesn't allow creature-traversal; the simplest is perhaps building a [[statue]] on the tracks. Other options include adding single-tile holes (minecarts moving at reasonable speed will jump the gap), vertical drops, minecart-triggered doors, small pools of liquid (4/7 water or 2/7 magma), and hostile creatures overlooking the tracks. For safety, both ends of the track should be isolated, making the dangerous center sections completely inaccessible (though maintenance access can be provided by a locked door).

Danger does not always involve living victims: careless route designation can also result in minecarts careening off tracks or colliding with each other. If this occurs, the [[item]]s may be scattered; this can cause even more hauling jobs than the minecart aimed to eliminate. Even <s>better</s> worse, scattered items, especially [[weapon]]s, can injure passing [[dwarf|dwarves]] or other [[creature]]s; in the words of Toady One the Great, "Accidental grapeshotting of the dining room should be possible now."

Of course, the danger of using minecarts means they can also be [[Trap_design#Minecarts|used as weapons]] by imaginative players.

== Advanced usage and automation ==
Minecart-specific effects are implemented via track stops, rollers and [[pressure plate]]s with "track" condition set. Since all three are considered [[building]]s, they can't be built on the same square (however convenient track stop + pressure plate would be) nor a simple ramp, and are removed by {{k|q}} {{k|x}}.

=== More on Track stop ===
Track stops are constructions that allow further automation of minecart systems via adjustable features such as braking by friction and automatic dumping of contents. They can be built from logs, bars and blocks through {{K|b}} {{K|C}} {{K|S}}; friction amount, dumping toggle and dumping direction must be set '''before''' construction, and these settings can be neither changed nor seen thereafter; however, track stops can be linked to [[pressure plate]]s or [[lever]]s to toggle friction and dumping On or Off (trigger state is inverted: switch On = track stop Off).

If a [[stockpile]] is placed on the tile that a track stop is set to dump to, it can act as a [[Exploit#Quantum_stockpiles|quantum stockpile]] and any items dumped from a minecart that match the storage settings of the stockpile will remain there and accumulate. Normally trackstops are built on top of existing track to operate on moving minecarts, but they can also be used without tracks to create [[Exploit#The_Minecart_Stop|automatic quantum stockpiles]] (see also [[#Step-by-step_tutorial|step-by-step tutorial]]). It is not always desirable to collect ALL of certain items into one quantum stockpile, such as when distributing a material to multiple separate industries. You can link your quantum stockpile to various other stockpiles, ensuring that your dwarves will keep them supplied as necessary. Because quantum stockpiles never fill up like regular stockpiles, it may be a good idea to add a switch to turn them off.

Items dumped from a minecart at a track stop (or dumped by any other means) into open space fall through z-levels until they land on a solid surface. Items falling onto a designated [[stockpile]] will automatically be considered part of that stockpile, even if the stockpile is set to disallow those items (they will, however, be automatically moved to a more appropriate stockpile, if available). Items falling on top of a minecart will '''not''' fall "inside" the minecart. Use with caution; dwarves have fragile skulls.{{bug|5945}}

=== Automated propulsion ===
==== Roller ====
{{Main|Roller}}

A '''roller''' is a [[power]]ed [[machine component]] for the automated propulsion of minecarts. They are built over the top of existing tracks with {{K|b|M|r}}, requiring a [[mechanic]], ''(length/4)+1'' [[mechanism]]s and a [[rope]]. Rollers may also be placed directly on ramps to help pull carts up Z levels. Rollers are very useful to maintain a cart's momentum along long routes, to get them to climb Z-levels without dwarfpower involved, and to get them to reach speeds unattainable by guiding dwarves. These devices are variable-length (1-10), variable-direction and variable-speed ([[Minecart#Numbers_behind_the_scene|see below]]), all traits that can be set at construction time; a roller uses two units of power per tile it is long.

Single-tile rollers transfer power in all four cardinal directions, while other rollers generally only transfer power perpendicular to their activity direction. Longer rollers can also transfer power along their activity direction if built in the correct order, although this can be hard to accomplish and is easily broken. Rollers cannot be powered from above.

Rollers have great acceleration and capped speed. Carts going faster than the roller are unaffected. If a cart moves across an active roller in the direction the roller works and moves slower than the roller's specified speed, the cart will be set to the roller's speed. A cart going against a roller's movement direction will be sent back the way it came (once again at the roller's speed), unless it was moving extremely fast: speed increment of 100000 allows to reverse carts from the full "highest" (50000) speed roller to full "highest" speed back, but ramps can accelerate a cart beyond this. {{cite forum|144328/5702453}}
A cart crossing over a roller perpendicular to its current movement direction will gain the roller's amount of speed in the perpendicular direction without directly changing its forward motion. Without an adjacent wall to constrict its movement, this will typically send a cart off the rails on a diagonal path, completely unable to follow any tracks until it collides with a wall or is otherwise brought to rest. However, if the roller is placed over a track turn and pushes ''from'' the direction of that turn's track, the turn affects carts ''after'' the roller, so they will be forced into the turn rather than derailed in a diagonal direction. {{cite forum|144328/5702453}}

{{diagram|spaces=yes|\
tracks: full:
║ ║
═╗═ ═╢═
║ ║

╢ : roller pushing from W to E
}}
If the roller is powered, carts from ''all'' directions (unless too fast) exit S, because speed imparted by the roller forces carts toward E and ''then'' into the turn.
If not powered, carts from W and N exit S, carts from E and S exit W. Carts above derail speed will ignore the turn, of course.

{{diagram|spaces=yes|\
║ ║
═╗═ ═╟═
║ ║

╟ : Roller pushing from E to W
}}
Carts from the E or W: exit W.
Carts from N: derailed diagonally, exit SW.
Carts from S: derailed diagonally, exit NW.

Rollers affects carts on a track - if placed on a floor or ramp without any tracks, they are ignored. Depowered rollers are also ignored, friction is determined by the tiles underneath.

Because of their one-way nature, rollers are unsuitable for most two-way minecart tracks (unless you set gears toggling roller A->B off while toggling A<-B rollers on). However, a minecart set to be ''guided'' is not affected by rollers at all{{cite forum|109460/3286235}} — this allows a one-way track to be used in both directions. In addition, unpowered rollers do not affect minecarts.

Care must be taken in [[glacier]]s and other extremely cold [[biome]]s, since rollers (and the machinery used to power them) will not operate when constructed on natural [[ice]] floors.

==== Impulse ramps ====
Carts can be given momentum without rollers or changing z-level through a phenomenon called "impulse ramps". A track ramp which is connected both to a wall and to a floor will ''always'' accelerate a cart towards the connected floor tile, no matter where the cart enters the tile from. This means carts can be accelerated as though dropping z-levels, even if the cart doesn't actually change z-level at all. If a track ramp faces three directions such as ╩, then two of those directions need to be facing walls for the cart to be accelerated towards the remaining direction.

Example of straight impulse acceleration:

{{diagram|spaces=yes|\
▒▒▒▒▒▒▒▒▒▒ ▒▒▒▒▒▒▒▒▒▒
═▲▲▲▲▲▲▲▲▲▲═ ═╚╚╚╚╚╚╚╚╚╚═
▒ : Wall
═ : Normal track
▲/╚ : N/E Track/Ramp
}}

If a cart enters from the left, it will speed up on every track/ramp and exit to the right going very very fast - more than one tile every step. If it enters from the right then it will bounce back impulsed by the ramp if it's going slow enough.

As another oddity, carts coming from ramps will in some cases "teleport" through most of the next tile. This can be used to send carts up levels with minimal loss of speed. You can just make an upward spiral alternating impulse ramps and regular upward ramps. It takes no power, is quick and cheap to build, requiring only channeling and track carving, and the cart goes up fast, but not so fast that it launches its contents.

Example of an impulse elevator:

{{diagram|spaces=yes|\
z +0 z +1 z +2 z +3
░░░░░ ░░░░░ ░░░░░ ░░░░░
░╔░░░ ░▼╚╗░ ░░▼▼░ ░░░░░
░╝░░░ ░▼░░░ ░░░╔░ ░░░▼░
░▼▼░░ ░░░░░ ░░░╝░ ░╚╗▼░
░░░░░ ░░░░░ ░░░░░ ░░░░░

░ : Wall
╔,╚,╗,╝ : Track/Ramp
▼ : Down Ramp (empty space)
}}

Note that this impulse elevator, due to the checkpoint effect and upward ramp curve effect, will not actually result in carts traveling straight up the ramp. They will lose speed, bounce off a ramp, then be accelerated back into the spiral after a 9-turn delay on both tiles on the floor where they are stopped. This is because the checkpoint effect allows carts to travel up the ramps in a single turn, but also prevents the impulse ramps from adding acceleration unless the cart is slowed to staying on the ramp for more than one turn. Initial acceleration will carry the cart up a variable number of floors before this effect occurs, but this bouncing back and forth will occur every 5 z-levels after the first time the cart stops. When the cart ''is'' traveling upwards, it will pass every tile at a rate of one tile per turn regardless of its actual speed, due to the checkpoint effect. In tracks with only a single cart, this is negligible, but when multiple carts are on the same track (such as when you place multiple carts on a magma cart lift) this can cause collisions which derail carts or cause other unexpected or undesired behaviors.

The following impulse ramp (while larger) should alleviate these problems by using a straight ramp to go upwards, preceded by an impulse ramp to exploit the checkpoint effect and negate up ramp costs. Corners still decelerate carts, so the cart will tend towards a velocity of 72k, which is derail speed. Derail checks may be necessary.

{{diagram|spaces=yes|\
z +0 z +1 z +2 z +3
░░░░░░ ░░░░░░ ░░░░░░ ░░░░░░
░░░░░░ ░╔╔═░░ ░░▼▼╗░ ░░░░░░
░║░░░░ ░▼░░░░ ░░░░╗░ ░░░░▼░
░╚░░░░ ░▼░░░░ ░░░░║░ ░░░░▼░
░╚▼▼░░ ░░░░░░ ░░░░░░ ░░═╝╝░
░░░░░░ ░░░░░░ ░░░░░░ ░░░░░░

░ : Wall
║,═,╔,╚,╗,╝ : Track/Ramp
▼ : Down Ramp (empty space)
}}

Also, if you want to have a cart following a regular speed, the following track works well:
{{diagram|spaces=yes|\
z +0 z +1 z +2 z +3
░░░░░ ░░░░░ ░░░░░ ░░░░░
░░░░░ ░══░░ ░▼▼║░ ░░░▼░
░║░░░ ░▼░░░ ░░░║░ ░░░▼░
░║▼▼░ ░▼░░░ ░░░░░ ░░══░
░░░░░ ░░░░░ ░░░░░ ░░░░░

░ : Wall
║,═ : Track/Ramp
▼ : Down Ramp (empty space)
}}
In this elevator, the cart collides with the walls in the corners, but then realigns on the ramp, picks up speed, checkpoints through the next ramp, and slams into the next wall. It is slower (10 ticks per floor) but produces reliable speeds, and will exit the impulse elevator at little more than push speeds.

A sort of opposite effect to impulse ramps also exists: ramps lacking the proper "up" and "down" connections are treated as flat track, even if they actually go up or down z-levels. This allows building "anti-impulse" slopes consisting entirely of ramps only connected up, which a minecart can travel up forty levels and more, needing no more than a single push.

=== Controlling traffic ===

==== Switching ====

As constructions or tile features, [[door]]s and other furniture can be built on tracks. A [[door]] or [[floodgate]] can be turned on or off by a [[lever]], effectively controlling the flow of automated minecarts. This may be <s>dangerous</s> [[fun]], however.
{{diagram|spaces=yes|\
->
A ════┤≡════ B
┤ : roller pushing to East
≡ : door
}}
The roller pushes the cart east, but until the "departure condition" is fulfilled, the door remains closed and blocks the path.

[[Bridge]]s can also act as tracks, but only if they're lowered or not retracted. This property can enable levers to turn tracks on and off. However, care should be taken to ensure that such bridges are never operated while a cart is on top of them, as the cart will be flung off the track. It's worth noting that it's often faster, and cheaper, to construct large bridges than long sections of constructed track.

A powered track switch can be constructed by building an "inverted" corner as illustrated below.
{{diagram|spaces=yes|\
B B
║ -> ║
║ ║
════╚═══ ════├════
A C A C
├ : roller pushing to West.
}}

If the cart is pushed East from the stop at 'A' while the roller is activated, it will arrive at 'B'. If the roller is not running, it will arrive at 'C'. The switch works by the roller first reversing the incoming cart's movement and the cart ''then'' following the track corner.

This switch is very reliable, reacts instantly to on/off signals, and carts of any speed can be switched by this design, although very fast carts will require rollers that are several tiles long, up to three. The requirement for power can be inconvenient or impractical. Non-powered solutions may use controlled derailment, or a connecting bridge.
{{diagram|spaces=yes|\
B ╥
║
║
╞════╝ ════╡
A D C
}}
Here the track between A and C is not continuous. The only continuous track is A->B, with a corner (not a T section). Fast moving carts will tend to derail at D and rejoin the track to C. Placing a door at D will prevent the derailment, so the cart continues to B. The door is operated by mechanisms elsewhere (typically, a lever, but some fun can be had with pressure plates).

Since it depends on derailing, this switch requires a very fast cart, faster than what can be achieved with rollers alone. To gain sufficient speed, a cart must be accelerated further, usually by descending several levels or through impulse ramps. The high speed makes the cart much more dangerous and harder to control.

If carts are moving too slowly to derail at the corner, a retractable bridge may be used as a connector between A and C.
{{diagram|spaces=yes|\
B╥
║
║
A╞════bbb════╡C
}}
The bridge must overlap the corner. Bridges behave like a track crossing, allowing carts to pass in a straight line. When retracted, the corner reappears, so the carts will continue to B. Bridges take 100 steps to react to a signal, necessitating rather long "lead times" when switching tracks via bridge.

As mentioned above, special care must be taken to make sure the bridge doesn't change state while the cart is passing over it. Retracting bridges will throw the cart, causing it to stop dead. Raising bridges can even crush the cart.

==== Controlling Speed ====


Minecarts can reach extremely high speeds, especially when descending multiple Z-levels. A minecart will derail at a track corner if its speed exceeds 0.5 t/st (tiles per step), '''unless''' the route in the direction of travel is blocked:

Will derail at > 0.5 t/st:

{{diagram|spaces=yes|\
in ══╗ -> derailing
║
out
}}

Will not derail at > 0.5 t/st:
{{diagram|spaces=yes|\
in ══╗O
║
out

O : wall/column.
}}

This behavior can be used to build a "speed limiter", that will ensure that when a minecart exits it is traveling below derail speed:
{{diagram|spaces=yes|\
░░░░ ░░░░░ ░░░░░
in ═╔═╗░ ░╔S╗░ ░╔S╗░
out ═╬═╝░ out ═╗═╝░ out ═╗═╝░
░╚S╝░ ░╚═╝═ in ░╚S╝░
░░░░░ ░░░░ ║░░░
in
░ : wall
S : Track Stop (High Friction or lower)
}}
If the minecart is traveling below derailment speed, it will not be affected; if above, will be slowed down and checked again. Granted, you could do the same just with track turns, but it may take a lot of turns and time.

Since all the derailings, bounces and ramps can impart a sideway component of speed small enough to start visible drift many tiles away (say, [[Fun|in the middle of a bridge]]), track turns have one more use: forcing the carts to move strictly along the grid directions. Carts passing a turn below derailing speed convert one component of velocity into another, thus eliminating the drift.

=== Loading liquids ===
[[Water]] and [[magma]] can also be loaded into minecarts by submerging them to a depth of at least 6/7 while standing still or moving at speeds of at most 10000. Loading fluids onto minecarts can be difficult because the added friction provided by fluids can stop a cart in a submerged tile. Curiously, filling a minecart with magma does not injure a dwarf ''riding'' it. A minecart will hold enough fluid to increase the depth of a single tile by 2. This amount is listed as 833 units, which weigh 459Γ (water) or 999Γ (magma). An iron or steel cart filled with magma weighs 1313Γ, while an adamantine cart filled with magma weighs 1007Γ. Since you need a minecart above the liquid's level, possible arrangements may include pressure-activated sluices, rollers (with magma-safe chains for magma), pouring from above to "submerge" it briefly on the same level and drain excess away (dig deeper and leave a vaporizer, though if you could have power for rollers, may as well use a pump) and exploits with ramps (not necessarily impulse ramps, "same height" passing dip does it).
The liquids can be dumped by a constructed track stop.

== Quirks ==
This little quirk concerns dwarf-managed minecarts. If a track which was previously open becomes blocked (ex. flipping a switch connected to a floodgate you've built on the track to raise it) and the conditions for departure are met, instead of refusing to ride/guide the minecart or ride/guide it until it reaches the obstacle, the dwarf will pick up the minecart off the tracks and haul it to its scheduled destination on foot. If the distance is long enough and the weight of the cart heavy enough (due to being filled with heavy items such as stones), the dwarf may drop the cart because of fatigue/hunger/thirst before reaching the destination. This will cancel that vehicle setting job and make another dwarf come by and attempt to haul the cart to the nearest appropriate stockpile where another dwarf will pick up the cart and attempt to haul it to its initial stop. If the stockpile is far enough from initial stop, this second dwarf who is attempting to place the minecart on its tracks may also drop the minecart out of fatigue/hunger/thirst creating a loop that will go on until a dwarf with enough endurance manages to place the minecart where it belongs.

In fact, it seems dwarves are more than happy to attempt to carry a minecart from one stop to another even if just waiting until the track is open again would be the more sane option.

Dwarves will also carry a minecart to its next stop if the direction specified is incorrect (or invalid). This can often occur when using the default departure settings and forgetting to set the direction of each condition.

Dwarves can admire buildings while riding mine carts. Dwarves will not fall asleep during a ride (at least not from being drowsy). If riding on a continuous powered track loop, the dwarf will die of dehydration/starvation as they can not jump off to get sustenance{{cite forum|109460/3377228}}. Dwarves riding in submerged minecarts will gain experience in [[swimming]].{{cite forum|129889}}

Tracks block wagon access to trade depots, unless they're on a ramp. [[Bridge]]s can also be used, as they function as tracks but do not block wagons.

== Physics ==


Minecart physics depend greatly on the departure mode set in the route stop conditions.

When set to "Push" or "Ride", minecarts will move according to the regular laws of momentum, gaining speed when going downhill, losing it slowly due to friction when on a flat plane, and more quickly when going uphill. In these modes, minecarts will move in a straight line until they either are brought to a stop by friction or an obstacle, or until they encounter a turn. A minecart will roll straight past "blocked" ends of T-junctions or track ends, they have no power to restrict a cart's movement. The cart's behavior is largely independent of the weight of its contents (including fluids and dwarves): heavily loaded carts gain more momentum when accelerating, but this only plays a role in collisions: a heavy cart gains just as much speed and is as easy to stop as a light one. In either case, dwarves can not push nor ride an unpowered cart up a ramp, bouncing back the direction it came. At best, this is a waste of time; at worst, it will give your cart-pushing dwarf a [[fun|fun surprise]]. To solve this, the player can either use Rollers (see below) or set the cart to be Guided.

The difference between "Push" and "Ride" is whether the dwarf will go along with the cart or not.
{{DFtext|Push}}: the dwarf will give the cart an initial push, not enough to go up a ramp, but enough to go some way along flat track, and the dwarf will remain at the first stop, ready for a new job.
{{DFtext|Ride}}: the dwarf will give the cart the same initial push and then hop aboard the cart riding with it to the next stop.
{{DFtext|Guide}}: minecarts seem to ignore all laws of physics. That is:
*Ignore the weight of any and all items inside. Therefore:
**Move at the speed of the dwarf that is guiding them. It is thus recommended to pick the most [[attribute#Agility|agile]] of your dwarves for cart-guiding tasks.
*Ignore working rollers.
*Will ''not'' collide with other guided carts even when a full frontal collision would be expected.
*Will go up ramps like nobody's business.
This is therefore the recommended method of transport for simple non-powered rail systems, despite it diverting a dwarf from other, potentially more important tasks.

Some samples with behavior:
{{diagram|spaces=yes|\
A <-> B A <-> C A <-> B
B B B
║ ║ ║
A══╝ A══╩══C A══╬╗
You can only go A->B ╚╝
Works when the cart Works
is in Guide mode.
}}
In the second example above, a cart "pushed" from B will go over the junction and roll off into the unknown south.

=== Track Direction Irrelevance ===
Carts that are traveling independently, (that is, not guided,) only care that tracks ''are'' on the tile, not which direction the tracks actually move. Tracks respect only curves (with two exits) and ramps.

This means, for example, that the following tracks, when a (non-guided) cart travels from West-to-East, are functionally identical in effect:

{{diagram|spaces=yes|\
A════════════B A╬║╚╔╣╩╦╠╥╨╞╡B
}}

This is because so far as the cart is concerned, only ramps and curves with two exits where the exit in the path they are traveling matters.

Hence, if a minecart encounters the end of the track or a T junction with no "exit" in its movement direction, it will simply leave the track and continue on its course in a straight line until it encounters an obstacle, slows to a stop, or encounters another track even if the tile at which it joins the new track instantly sends it around a corner.

In fact, a "║", a "╦", a "╬", and a "╥" are ''only different in appearance'', and are ignored by the cart, which will continue in its current direction, regardless of the track.

Carts only check for curves when they are halfway through a tile. When they get there, they look to see if their path has no exit. (That is, if it is traveling East, it checks if there is an East exit.) If there is, it ignores all other track directions, and keeps traveling. If there is not, it checks to see if there are only two exits to the track, and if one of those directions was the direction it "came from". (That is, if traveling from the East, it checks if there is a valid exit to the West, and if so, if there is either a North exit or a South exit.) If there is not, it ignores the track anyway, and keeps on traveling as though it were still on track. If there is, it will subtract 1000 from the velocity of the cart, and redirect all forward velocity to the direction of the curve. This change in the direction of velocity ''overwrites'' any "diagonal" velocity, which can prevent diagonal velocity derailments, but any perpendicular velocity is not preserved, and is instead discarded.

=== Valid and Invalid Ramps ===
Ramps are functionally defined for cart purposes as being a tile which exerts an acceleration force upon its "downward slope", and which allows connection to tracks a z-level above or below. This downward slope requires a cart to have one ''and exactly one'' carved exit to the tile that is the "bottom" of the ramp. Ramps accelerate carts in this "downward" direction (possibly leading to diagonal movement, below), and the deceleration of an "uphill" ramp is actually just the acceleration being applied against the direction of a cart's movement.

This is where players can find an exploit in the behavior of ramps - if there are ''two'' "downhill" exits to a ramp (such as a "T junction" on a ramp where only one exit faces a wall), then the ramp provides no acceleration ''or'' deceleration, allowing carts to travel up ramps without any loss of momentum except for the standard "flat track" deceleration, because as far as the cart is concerned, the track ''is'' flat. (A T junction is also not a curve, so the track is considered flat and straight no matter what direction the cart is traveling.)

Similar effects can be achieved when there are ''no'' "downhill" exits to a ramp. This may be the case if you have, for example, an East-West track with a one-tile channel with a ramp in it. The cart will travel through the "dip" with no change in velocity. It can also be the case if you abuse the Track Direction Irrelevance, above, and set only exits ''up'' the ramp, and none leading ''down'' the ramp. For example, if a cart is traveling from West to East up a slope, only carving East exits on each tile of ramp will make the cart travel up the ramp, and then recognize the tile it is on as being a "flat" tile, thus ignoring any deceleration from traveling uphill. Note that this effect only reliably occurs at relatively slow speeds (at around push, or single accelerating ramp speeds) as the cart may simply ignore the ramp and crash into the wall at higher speeds.

=== Falling ===
When falling, a minecart appears to cause no damage upon collision, possibly to allow cart "stacking" across Z-levels.{{cite devlog|2012|04|06}} A dwarf riding in a minecart that is dropped multiple z-levels suffers normal fall damage. Minecarts can fall through up/down stairs.

While airborne, carts do not feel the effects of friction in any horizontal direction, and will continue until they strike an obstacle. Carts that land on tracks instantly re-rail themselves regardless of track directionality.

Falling carts accelerate similarly to the way that a ramp will accelerate a cart in a special z-only velocity that only applies to airborne carts. (Actually, acceleration due to gravity in freefall seems curiously slightly ''slower'' than ramp acceleration.) Ramp acceleration, while it logically should be partially z-directional, is only recorded as x- or y-directional, and there is no translation of z-directional velocity upon landing. Landing carts zero out their vertical velocity upon landing, even when landing on ramps, although carts that had horizontal momentum while falling preserve it.

This means a cart falling (from a hatch, thus with no horizontal speed) onto a track ramp is accelerated as if starting from the middle of the ramp - i.e. to the same speed, no matter how many Z-levels it was dropped, vertical velocity is negated. {{cite forum|144328/5701211}}

Carts falling onto a floor can, however, cause damage to creatures ''one tile below the floor''. This can be used in an [[exploit]] called a "thumper", where carts are caused to repeatedly fall on a floor above an entrance to the fort, inflicting significant damage (as though it were a collision) on those below the cart.

=== Cart Jumps ===
Carts that cross off of "up" ramps relative to their current direction of travel, which do not have a ceiling above them, and do not have valid ramp track before them can translate a portion of their horizontal velocity into vertical velocity, causing a cart to be projected into the air until vertical velocity is negated and overcome by the gravitational acceleration. Because downwards acceleration is applied per-tick, this creates a reasonable facsimile of the parabolic motion of an actual object rolled up a ramp and launched with significant speed.

{{diagram|spaces=yes|\
z0 z0 hiding ramps z+1 A z+1 B (hidden ramp)
▒▒▒▒▒▒▒▒▒▒▒▒ ▒▒▒▒▒▒▒▒▒▒▒▒ ▒▒▒▒▒▒▒▒▒▒▒▒ ▒▒▒▒▒▒▒▒▒▒▒▒
═▲▲▲▲▲══▲▒▲═ ═╚╚╚╚╚═══▒══ ▼▼▼▼▼ ▼═▼ ▼▼▼▼▼ ▼╚▼
▒ : Wall
═ : track
▲ : Ramp
}}
In this diagram, if there is no ceiling above it, the track in z+1 A will launch its carts airborne when they travel across the ramp. z+1 B (with a ramp on the tile on the hill) will not launch the cart. The cart would also not be launched with ''any'' valid ramp, even if it does not travel in an appropriate direction, such as North/South (which the cart will ignore, as it is not a curve, anyway, although it may produce acceleration that may cause diagonal movement.)

Tracks that are travelling at high enough velocity will also start "jumping" from track if it hits an un-tracked tile (flying over and ignoring any tracks) until it is ready to land. Carts that land upon tracked tiles re-rail themselves, and clever designers use this feature to jump over curved track sections in one direction or another. (Retracting bridges over untracked tiles can cause jumps or not cause jumps depending upon the status of the bridge.) Minecart speed must be carefully regulated to ensure reliability of jump length.

This creates a vertical component to acceleration that allows for jumps of around 6 (horizontal) tiles that do not actually leave the z-level the cart is on, but which do apply z-direction velocity on the cart, as per falling.

Carts that approach a downward slope at a high enough velocity will also make a jump, but will not do so if the Checkpoint Effect (below) is exploited through an impulse ramp before the actual downhill as the impulse ramp "tricks" the cart into thinking it has already started going downhill.

=== Skipping ===
If a minecart is moving fast enough, it can skip over [[water]] or [[magma]], making splashes of [[mist]] (or [[magma mist]]) as it attempts to move on them horizontally. This horizontal movement is independent of the minecart and its content's [[weight]].

Skipping causes significant friction on the cart, and even a cart going at max speed from ramps can only make about 50 tiles without requiring re-acceleration. (Carts that decelerate enough that they do not trigger the skipping effect will, of course, sink.)

=== Corner Ramp Derail ===

Corners on upward ramps can cause diagonal movement, forcing a derail even if the cart has a wall next to it, which will force a stop when it touches a wall that forces dwarves to manually reset the cart.

This is caused by the fact that a cart, after turning the bend in the track halfway through the length of the tile, will still "accelerate down", which is now perpendicular to the movement of the cart, causing acceleration to occur in two directions. (Down corner ramps do not have this problem, as when they pass the halfway point, all perpendicular motion is added to forward motion, and after that curve, all downward acceleration is in the forward direction.)

There are two fixes to this problem. One is to simply not put corners on up ramps. The other is to take advantage of the Checkpoint Effect, below, by making a ramp (possibly including an impulse ramp) one tile in front of the ramp to make it skip through most of the tile before sideways momentum can be built.

=== Checkpoint Effect ===
The checkpoint effect, [http://www.bay12forums.com/smf/index.php?topic=144328.0 explained in depth by Larix], is an odd and highly exploitable feature of ramps where minecarts "teleport" through the next tile of track, ignoring nearly all minecart physics (except that they stop at all walls or other obstacles and not only respect curves, but will take them even when they would otherwise derail) and passing through that tile in just a single tick, and into the next tile at the halfway point.

This effect occurs when a cart leaves a downward ramp for any other direction of tile. (This includes ramps which accelerate in different directions, even a ramp which goes from accelerating East to accelerating North due to a bend in a chain of standard down ramps in a curve.) This allows, for example, two valid straight ramps directly next to one another with a cart dropped onto one or the other with no momentum to have the cart pick up acceleration going "down" the ramp as normal, but then flying up through the "up" ramp it travels into with no loss of momentum, as though it had come from an impulse ramp. If the two ramps had at least one space of distance between them, and then a cart were dropped in, the cart would instead "rock" back and forth between the two ramps.

This seems to be because ramps have a slightly longer length than regular tiles - 144,000, rather than 100,000 distance. When this "snaps back" after a ramp, it seems to project the cart suddenly further along the track, making it jump a tile ahead even when otherwise moving at relatively low speeds.

This [[bug]] is the cause of a ''wide array'' of unexpected behavior among people who do not take this bug into account. It causes derailments or failure to climb up seemingly valid impulse elevators. In general, it makes a system that behaves extremely counter-intuitively, and operates ''any time a cart encounters a valid ramp''. At the same time, when its effect is accounted for, it is highly exploitable: It causes "perpetual motion devices" using no power when two opposing ramps are placed next to one another, since the "uphill" effect of the opposing ramp is ignored, preventing deceleration.

Another useful thing to note about this exploit is that carts traveling at no less than 72,000 or so speed (enough to travel half a ramp tile in a single tick) can travel through every tile in just one tick at no change in velocity as long as the tiles alternate between impulse ramp or actual down ramp and any other tile type. The cart checkpoints through the non-down-ramp tiles, and can pass through the (impulse) down ramp tiles in a single tick, before they can actually start gaining momentum.

{{diagram|spaces=yes|\
▒▒▒▒▒▒▒▒▒▒ ▒▒▒▒▒▒▒▒▒▒
═▲═▲═▲═▲═▲═ ═╚═╚═╚═╚═╚═
▒ : Wall
═ : Normal track
▲/╚ : N/E Track/Ramp
}}

If the cart enters from the West at less than 72,000 speed, some of those ramps will cause Eastward acceleration.

This means that an impulse ramp not contiguous to other impulse ramps has a top speed of around 75k:

{{diagram|spaces=yes|\
▒▒▒▒▒ ▒▒▒▒▒
▒╔═╗▒ ▒╔═╗▒
▒╚▲╝▒ ▒╚╗╝▒
▒▒▒▒▒ ▒▒▒▒▒
}}
This setup makes a cart that travels clockwise at a speed that fluctuates around 75k velocity. If the cart has more than 72k velocity, it fails to accelerate in the ramp, as it leaves the ramp in a single turn due to checkpointing to the halfway point. After that, the curves sap 1k velocity, and every tick saps 10 velocity.

Two contiguous impulse ramps with a same-facing "downwards slope", however, do not suffer the checkpoint effect in the second tile, giving functionally triple the space to accelerate. This means it will add velocity (at the standard rate of 4.9k per tick) up to a maximum speed of 216k.
{{diagram|spaces=yes|\
▒▒▒▒▒▒ ▒▒▒▒▒▒
▒╔══╗▒ ▒╔══╗▒
▒╚▲▲╝▒ ▒╚╗╗╝▒
▒▒▒▒▒▒ ▒▒▒▒▒▒
}}
This example results in a cart moving three times as fast as the previous cart.

Three successive ramps results in the highest attainable speeds.

In practical terms, this means that only consecutive ramps should be used for high acceleration, but singleton ramps can be used to have speeds that are somewhat regulated.

=== Stacking ===
If a minecart lands on top of another minecart, they may form a stack, with the upper cart on the z-level above the lower. Subsequent carts do not form a stack, but rather quantum stockpile in the same space. This behaviour is useful for [[megaprojects]] and [[trap design]] with minecarts as the weaponry. Moderation should still be exercised: carts take longer to fall into a "stacking" tile already occupied by other carts and will spend that time "hanging" in the air above the stack. This can lead to following carts striking them, which can cause all kinds of malfunctions. The extra time is two game steps for every cart already in the stack, which doesn't hurt stacks of ten carts very much but makes stacks of 100+ rather impractical.

These minecarts on the upper level generally need to be struck with another minecart to move out, or have their support removed. The latter option is safest done by shooting it away with another minecart, manual removal of a stack-supporting cart typically causes the next cart from the stack to [[fun|fall on top]] of the hauler.

=== Perfectly Elastic Collisions ===
Minecart collisions are perfectly elastic, meaning that not only do minecarts not take damage, but that two carts that are rolling which have frontal collisions of near-similar speed, and where one cart is no more than twice the mass of the other cart, will result in a billiard-ball-like effect of the lighter cart bouncing off the heavier cart with a proportional speed increase dependent upon the relative momentum behind the heavier cart.

Using this trick with carts already at the 270,000 maximum speed from ramps can result in "supersonic" carts traveling at speeds in the millions (travelling a dozen tiles per tick), but where they are suddenly subject to 10,000 units of "terminal velocity" friction per tick. [http://www.bay12forums.com/smf/index.php?topic=137557.0 Thread with SCIENCE here].

While hypothetically capable of launching a minecart into orbit when used in conjunction with a ramp, no cargo can be contained in the launched cart, as the collisions will force ejections of the cargo. Your "unwilling volunteer" [[goblin]] space pioneers will simply become paste underneath the wheels of an extreme high-speed cart.

=== Numbers behind the scene ===

According to early research by '''expwnent'''{{cite forum|112831/3536975}}:

The minecart has a variable for speed. Speed is measured in tiles/100000 ticks, so a speed of one hundred thousand means one tile per tick. By going down a large number of ramps, a maximum speed of 270,000 can be reached, which presents the limit for most practical applications. Short bursts of (much) higher speeds are possible through carefully planned collisions of high-speed carts {{cite forum|137557/5145499}}.

Every tick the cart accumulates distance units, as well as slows down depending on current tile (speed is reduced by "friction" of the tile). The cart will move to the next tile the tick before accumulating 100000 distance units, (or several tiles in case of great speed), then the leftover distance units are added to the default 100000 distance u. of the next tile. Since most deceleration and acceleration is applied per step, with the notable exception of corners, a cart going at twice the speed of another one can cover about four times the distance in a straight line, but only twice the distance along a winding track with very many corners.

A push will teleport a cart to the beginning of the next tile (NOT the middle!) in one tick with 19990 speed (10 speed is lost due to track friction), while a roller will give a cart the roller's set speed, and it will start to accumulate regular track friction past the middle of the roller tile. Some track features will affect a minecart when it is past the middle of the previous tile: entering a ramp or a hole/drop will happen when the cart has left the middle of the previous tile, and the ramp will gain additional distance unit depending on the leftover units from the previous tile. When a cart leaves a ramp it will emerge after one tick in the middle of the next regular tile, so its entry coordinate is "50000-speed+friction". Rollers also affect the speed of minecart from the middle of the previous tile.

Friction of tiles:
{| class="wikitable"
|-
! Tile
! Friction
! Comment
|-
| Tracks
| 10
|-
| Ground/Floor
| 200
|-
| Unusable ramp
| 10
|-
| Upwards ramp
| 4910 (10+4900)
|-
| Downwards ramp
| -4890 (10-4900)
|-
| Roller
| ±100000 (but capped by the set speed)
|-
| Corner track
| 10
| Speed reduced by 1000 upon leaving the corner tile
|-
| Track stop (highest)
| 50000
|-
| Track stop (high)
| 10000
|-
| Track stop (medium)
| 500
|-
| Track stop (low)
| 50
|-
| Track stop (lowest)
| 10
|-
| Water 1-6
| Additional (WaterLevel - 1) * 100
| rowspan="2" | [[#Skipping|See Skipping]]
|-
| Magma 1-6
| Additional (WaterLevel - 1) * 500
|-
| Empty space
| 0
|}

Water of depth 7/7 provides a friction of about 10000 per step, as does maximum-depth magma. This higher friction may not apply to very slow-moving carts.

Impulse sources:
{| class="wikitable"
|-
! Feature
! Speed
|-
| Push
| 20000
|-
| Roller lowest
| 10000
|-
| Roller low
| 20000
|-
| Roller medium
| 30000
|-
| Roller high
| 40000
|-
| Roller Highest
| 50000
|-
|}

== Non-standard uses ==
Minecarts include some interesting characteristics that have motivated uses beyond hauling. They can be useful for creating fully-automated [[exploit|quantum stockpiles]] and [[garbage disposal]]s. Storing perishable goods (meat, meals, etc.) inside a minecart appears to guard against rot and vermin.
Minecarts can be [[Trap_design#Minecarts|used as weapons]], or as (hopefully non-fatal) triggers to restart stalled [[healthcare]]. They can also be used to time/control game events, either using a basic [[repeater]] or much more advanced [[minecart logic]].
Minecarts trigger [[pressure plate]]s, which means a trap can be designed to trigger when a thief attempts to steal a minecart.
A pressure plate can be used as automatic and more precise custom "launch when full enough" system - as long as weight of your minecarts stays the same. You cannot build a hatch or roller on the same tile, so launch by bumping with another cart. {{cite forum|15096/4580050}}
Dwarves riding minecarts can attack enemies within reach (which goes back to dev log). This applies to shooting, and they actually can hit targets while riding by.{{cite forum|109460/5266119}} Whether a minecart protects the rider and how it interacts with dodging is not known yet. Minecart riders can also [[Swimming#Minecart_training|train swimming]] and [[Megaprojects#Surveillance_Track|detect ambushers]].

== Adventure mode ==
In addition to being used for hauling, minecarts can also be ridden in [[adventure mode]]. (Adapted from forum thread {{cite forum|122903/4258212}})

# If the minecart is in your inventory, drop it. If it is already on the ground, proceed to step 2.
# Press {{k|u}} when you are 1 tile away from the minecart (or standing on the same tile as the minecart).
# You will be presented with the following options:
[[File:minecart adventure mode menu.png|left]]
{{clear}}
* If you {{DFtext|Push}} the minecart, it will move a few tiles in the direction you chose. Physics comes into play here, so it will gain/lose speed depending on the usual factors.
* If you {{DFtext|Ride}} the minecart, you will hop into the minecart, even if you were a tile away, and it will move in the chosen direction with you in it. It will gain/lose speed depending on the usual factors. Whilst the minecart is in motion, you should press {{k|.}} to skip your turn; if you attempt to move whilst the minecart is still in motion, the laws of physics come into play, and you will take [[wound|damage]]. Alternatively, you can push the minecart whilst it's still in motion (although it's unclear how one can bend [[physics]] so as to push a moving minecart whilst inside the minecart). If you push it in the same direction you are already travelling in, you will greatly increase the minecart's velocity. You can also push it in different directions, and this will cause it to gradually change direction-the amount of pushes this requires depends on the minecart's velocity. Once the minecart has stopped moving, you may move out of it safely, or you may want to give it another push. Note that if you push a minecart right after having ridden it (still on the same tile as the minecart), it will act as though you chose to ''ride'' it.

If you want to test this out without creating an adventurer, the [[object testing arena]] allows you to spawn minecarts ({{k|k}}-{{k|c}}-{{k|n}})

== Forging and Melting ==
* Metal minecarts cost '''two''' [[metal]] bars to forge, or '''six''' [[adamantine]] wafers.
* When a non-adamantine metal minecart is melted down, it will return '''1.8''' metal bars, for an '''efficiency of 90%'''.
* When an adamantine minecart is melted down, it will produce '''1.8''' wafers, for an '''efficiency of 30%'''.

== See also ==
* [http://www.bay12forums.com/smf/index.php?topic=109460.0 The "How Does Minecart" Thread] by '''Girlinhat''' et al.
* [http://www.bay12forums.com/smf/index.php?topic=112831.0 SCIENCE: Quantifying minecart physics] by '''Snaake''' et al.
* [http://www.bay12forums.com/smf/index.php?topic=129676.0 How to build a Multi-cart Ore to Magma Minecart Project without needing power] by '''WanderingKid'''.
* [http://www.bay12forums.com/smf/index.php?topic=144328.0 My very own Minecart Education Thread. Ten Lessons, now complete.] by '''Larix'''.

== Bugs ==
*A dwarf will drop her [[child|baby]], if she has one, when boarding a minecart set to be ridden.
*Dwarves have no concept of traffic safety and will walk into busy minecart lines to retrieve objects, often with deadly consequences. This is especially problematic in [[Swimming#Minecart_training|clever applications]] depending on dwarves riding the carts very frequently, because they have a bad habit of dumping their worn clothes on the tracks after a minecart ride. Adding an automatically-operated [[hatch cover]] at the end of such a ride can help prevent [[unfortunate accident]]s.
*Dwarves cannot guide a minecart through an unlocked door unless another dwarf opens the door.{{bug|6056}}
*It is possible for a creature and minecart moving towards each other to pass without collision if they exchange tiles in the same tick.
*After a minecart ride, a dwarf will sometimes haul the minecart to a storage stockpile, leaving another dwarf to haul the vehicle back to the route.
*Minecarts falling onto a floor injure creatures in the tile below the floor.{{bug|6068}}
*A minecart's initial velocity is not affected by weight, when pushed or launched from rollers.{{bug|6296}}
*Removing a stop that has a vehicle waiting on it may cause the game to crash.{{bug|5980}}

{{Category|Fortress mode}}
{{Category|Interface}}

[[ru:Minecart]]

Minecart

2015-06-18T19:05:35Z

NW Kohaku: /* Physics */ Diagrams and reordering to make more basic concepts come first

{{Quality|Masterwork|08:15, 19 May 2015 (UTC)}}
{{av}}
A '''minecart''' is a [[tool]] intended for [[hauling]], introduced in version 0.34.08. It can be made of [[wood]] at a [[carpenter's workshop]] or [[metal]] at a [[metalsmith's forge]] (using the [[Metal crafter|metalcrafting]] labor.) Minecarts store up to five times as many items as [[wheelbarrow]]s and are quite a bit faster than dwarves hauling objects by hand, but have the disadvantages of requiring a dedicated track network, a complex route planning phase, and the possibility of dwarves [[Fun|blundering into the path of carts filled with lead ore]]. Tracks may be carved into stone, or [[Construction|constructed]]; the latter allows above-ground routes, but these are more difficult to set up due to their additional [[building material|material requirements]].

Just like wheelbarrows, minecarts are considered [[item]]s and are stored in a [[furniture]] [[stockpile]]. Despite their five-times-greater capacity, they are only 33% larger than wheelbarrows and are identical in base [[item value|value]] when made from the same [[material]] (the value may differ due to the [[item quality]]). [[thief|Thieves]] or even mischievous animals can steal minecarts, even when they are moving on a track{{cite forum|109460/3289070}}. However, minecarts moving fast enough or being ridden cannot be stolen.

Although most of the utility of minecarts is in [[fortress mode]], an [[adventure mode|adventurer]] can also ride in a minecart. Adventurers can also pick up and relocate minecarts.

The invention of minecarts revolutionized the [[minecart logic|Science of Dwarfputing]] by enabling smaller, faster logic systems to be built.

== Basic Minecart Usage ==
Minecarts can be used to swiftly transport dwarves, [[flow|fluids]], and/or large amounts of items, but before you have a functional minecart there are several preconditions that need to be met. First of all you need an actual minecart, constructed either in a [[carpenter's workshop]] or [[metalsmith's forge]]. For the minecart to be able to move you also need to carve (with {{k|d}} {{k|T}}) or construct (with {{k|b}} {{k|C}} {{k|T}}) a track, which could be as simple as a straight line. Finally you need to construct stops on your track (with {{k|b}} {{k|C}} {{k|S}}) where the minecart will start and stop.

After you have created the stops and assigned a cart to the track, you must create logic routes connecting several stops and designate starting conditions for each stop. This is done with the {{k|h}}auling key. The most basic conditions are how the cart's movement is initiated and in which direction the cart should start moving. Carts can be either be Pushed (a dwarf stands at a stop and gives the cart a single push) or Guided (a dwarf continually pushes the cart forward, guiding it along the track). The [[hauling]] [[labor]] required for pushing and guiding carts is called "Push/Haul Vehicles" and is turned on by default.

To control which items to transport you can add conditions specifying: (1) which kind of items to be loaded, and unloaded, (2) stockpile links to define which stockpile(s) the items should be un/loaded to and from.

===Capacity and weights ===
Minecarts have five times the [[Weight|capacity]] of [[wheelbarrow]]s.

'''Examples of the capacity of one cart'''
{| class="wikitable"
|-
! Item
! Amount
|-
| [[stone]]
| 5
|-
| [[wood|log]]
| 10
|-
| [[block]]/[[bar]]
| 83
|-
| [[Kitchen|prepared meals]]
| 500
|-
| [[Trap_component#Spiked_ball|spiked balls]]
| 500
|-
| [[Weapon#Native_weapons|mace]]
| 625
|-
| [[Weapon#Native_weapons|spears]]
| 1250
|-
| [[cloth]]
| 2500
|}

The weight of the loaded minecart does not affect the initial velocity received from pushing or launching from a roller. However, the load of a minecart ''does'' affect whether a [[pressure plate]] triggers or not, based on the pressure plate's setting.

'''Weights of different carts'''

{| class="wikitable"
|-
! Type of cart
! Empty cart
! Fully loaded (items)
|-
| oaken minecart
| 28Γ
| 378Γ (10 oak logs)
|-
| platinum minecart
| 856Γ
| 10482Γ (83 gold bars)
|}

The weight of a minecart is one twenty-fifth (1/25) the [[density]] of its material in Urists. Because pressure plates can be set to trigger at intervals of 50 Urists, minecarts with weights just under a multiple of 50 are ideal for switching based on whether they're full or empty. The best minecart materials for full/empty switching are as follows:

{| class="wikitable sortable"
|-
! Material !! Minecart weight !! Content weight required to trigger !! Banana roasts required to trigger (for scale)
|-
| [[Bismuth]] (moods only) || 391 || 9 || 15
|-
| [[Brass]] || 342 || 8 || 14
|-
| [[Electrum]] || 596 || 4 || 7
|-
| [[Fine pewter]] || 291 || 9 || 15
|-
| [[Glumprong]] || 48 || 2 || 4
|-
| [[Lay pewter]] || 291 || 9 || 15
|-
| [[Nickel silver]] || 346 || 4 || 7
|-
| [[Tin]] || 291 || 9 || 15
|-
| [[Trifle pewter]] || 291 || 9 || 15
|}

=== Creating tracks ===
Minecart tracks are made up of contiguous track, tracked ramp, or bridge tiles. Track tiles and tracked ramp tiles have a direction or series of directions associated with them. These directions dictate which directions a minecart on a given tile may move from that tile. For example, a Track NE (northeast) tile allows a minecart on it to move either north or east from its present position. Therefore, if you want your minecart to move east along a straight piece of track, then return west using that same track, you would need to use EW tracks so that the cart could travel east initially, then return west over the same track. Excluding designs in which the cart will "jump" tracks via a drop or other ramp, tracks must be valid end to end to work for most looped or straight-track applications. A single east only track tile in your line of east-west tracks will cause any route using the track to fail the moment it tries to go the wrong way over that tile. Minecart tracks can be built in two ways: Engraved/carved or constructed. A given minecart track need not use engraved or constructed elements exclusively, as the two methods can be used interchangeably depending on the needs of a given section of track. The way the tracks are built is slightly different between the two, as explained below.

====Simple tracks====

'''Carved'''

A single-tile wide strip of natural stone can be designated to be [[Engraver|carved]] (with {{K|d}} {{k|T}}), which will create a straight two-way track. The creation of corners, crossings, and T-junctions is as simple as designating another strip of track that overlaps an existent or newly designated track. Engraved tracks are removed by [[smoothing]] the rock they're on, which results in a smooth floor (that can be re-engraved if necessary), or by building a [[floor]] on top and subsequently removing it. Dwarves can carve corner tracks in one pass by designating the track carving twice and canceling unwanted carvings (with {{K|d}} {{K|x}}). Tracks can be engraved in any natural floor tile, rough, smooth and even over engravings, providing an easy method to remove low-quality or undesired floor engravings. Once a track has been engraved, it's important to check the track directions for each tile in the route carefully to make sure no mistakes were made by yourself or the game's track engraving logic.

'''Constructed'''

Tracks can also be built as regular [[construction]]s (through {{K|b}} {{K|C}} {{K|T}}). This method is resource-expensive, since each track tile requires one stone, [[bar]], or [[block]] for construction, and time-consuming, since you can't designate strips longer than 10 tiles at a time. Corners, crossings, T-junctions, and ramps also have to be designated individually. However, it is usually the only way to build tracks above ground or on soil (barring the [[Obsidian farming|creation of obsidian]]). Constructed tracks are designated for removal like any regular construction; be aware that removing track ramps built on top of natural ones will also remove the original ramp, leaving a flat floor.

====Ramps====

'''Carved'''

The carving of natural ramps is a little more confusing: to carve a two-way track on a ramp (natural only, does not work on constructed ramps), you must designate the track '''starting on the ramp and one square beyond''' in the direction you want the track to go. For the side of the ramp square you want to head upward, there '''must''' be either a natural or constructed wall in the square next to it, otherwise the game assumes you are trying to carve it on the same level -- this can result in the track being carved underneath a door or other object. If you have accidentally done this, you can correct it by smoothing the ramp and constructing a single square of wall next to it, then re-carving the ramp correctly. (However, the wall must stay there permanently; removing it will disconnect the track.)

'''Constructed'''

When constructing track ramps, the stated direction should be the same as the connected tracks. For example, a track going up from West to East would require, starting from the West, a Track (EW), a Track/Ramp (EW) and a Wall behind the ramp, underneath the section of track above it. Incorrectly placed ramps result in minecarts ignoring the ramp and crashing into the supporting wall. They will not, however, display as unusable as when the supporting wall is missing.

'''Examples of ramps'''

A simple ramp would look like this:
{{diagram|spaces=yes|\
z +0 z +1
░░░░ ░░░░
═▲o ░▼═
░░░░ ░░░░
o : wall
}}

Carving track corners into ramps is rather unintuitive and complicated. Since engraving tracks always requires two tiles to connect in a straight line as input, you have to give two separate designations for a single job: a track bit from the ramp tile to the "below" direction and another one to the wall of the "upward" direction. If you wanted to change direction on a ramp from east to north:
{{diagram|spaces=yes|\
z +0 z +1
░░░░░ ░░░░░
░░░░░ ══╗░░
=▲░░ ░░▼░░
░░░░░ ░░░░░
}}
you would need to connect the ramp on z +0 both to the west and to the north by issuing two "carve track" commands, one selecting the ramp and the track tile to the west, and another connecting the ramp tile with the wall to the north. An engraver would then carve a NW track corner into the ramp, allowing carts to pass the corner correctly both going up and down. Such track corners are perfectly serviceable for guided carts, but moving down a route of several of them by pushed or ridden cart is problematic - ramps on corners behave very counter-intuitively, resulting in loss of speed when going down and diagonal movement when going up.

Moving to and from ramps (or between ramps "pointing" in different directions0 causes some non-trivial adjustments to speed and even moving along the tiles at a fixed speed ''unrelated to the entry/exit velocity values'', because transitions to/from ramps are processed differently and are not to be "skipped". This affects compact track/ramp combinations (such as e.g. a simple 2x2 ramp spiral) most, and combined with bouncing often makes them work not in the way one could expect. {{cite forum|144328/5705102}}

{{anchor|Tracks}}

=== Hauling route ===
A hauling route is a list of directions describing how and under what conditions a minecart will move. The proper setting up of routes is essential for a working rail system. Routes, stops, departure conditions and stockpile links are managed from the {{k|h}}auling menu.

==== Route ====
A route defines the path a minecart will take along a track, as well as under what conditions it will move or stop moving. A route is made up of stops. Stops are precisely what they sound like, a position on the track at which you want a minecart to stop. A minecart track might use as little as a single stop for a looped track, which will serve as both a starting and stopping point for the cart, or it could contain many stops, perhaps to load supplies or wait for a bridge to be manually lowered, before reaching its destination or returning to its starting point. It is important to note that you only need to place stops on a route where you actually want the cart to stop and wait for some action to occur. They are not needed to help navigate the cart along the track beyond telling it where on the track to stop.

New routes are created with the {{k|h}}auling key. Existing ones can be removed (without confirmation) with the {{k|x}} key, and also {{k|n}}icknamed. Before operating, the route must have a {{k|v}}ehicle assigned to it (this can be done with either the route or a stop selected). Assigning a full minecart to a route may result in a slow hauling job if the contents are heavy.

==== Stops ====
Stops are the individual waypoints that make up a hauling route. A given stop consists of the location of a tile, as well as conditions describing when, where, and how a cart should be moved after being stopped at that tile. Stops can be created from within the {{k|h}}auling menu, by placing the cursor over a tile and hitting {{k|s}} while highlighting the route (or a stop within) you've already designated. A minecart will begin its route at the first stop created, and continue through each subsequent stop, being guided, pushed, or ridden from each stop to the next depending on the conditions specified. In many basic minecart applications, the cart will end up at the same stop it began at, though this is not always the case. It is important to note that hauling stop order is enforced, even if there is no track. A dwarf will drag the cart overland back to a skipped stop in the route's list if your tracks bypass it somehow.

Once a stop has been placed, it is given a default set of conditions under which to move the minecart if it is stopped there. Each new stop gets the same default conditions regardless of the track it is placed upon (e.g. guide the cart to the north). For this reason new stops might get marked by yellow exclamation marks ({{DFtext|!|#ff0}}) due to invalid directions. One important thing to note is that as you place additional stops, the display will show paths between the stops you have defined. However, this is '''not''' necessarily the actual route the minecart will take once the route is in operation. For example, if a route were defined with two stops at opposite ends of a track with many twists and turns, a line will be drawn directly between those stops to show the order in which they will be visited. These route lines may crisscross all over the tracks, but so long as the track is valid end to end, the cart will follow the track from one stop to the next, even across twists, turns, and z-level changes. Stops, which are the steps that make up a route, should not be confused with Track Stops, described below.

===== Stockpile links =====
By placing the cursor on top of a stockpile and using {{k|s}}, you can create stockpile links while defining a hauling stop. Links can also be redefined by selecting them, placing the cursor over a different stockpile, and pressing {{k|p}}. The cart will then be filled by items present in its various linked stockpiles in preference to other items. Note that bins should be used with caution in stockpiles that are linked to minecarts. Bins cause problems when used with the "Desired Items" list in a stop's conditions. For example, if a minecart is set to accept only granite blocks, and to depart north when it is 100% full of granite blocks, it will not depart if any of those granite blocks are in bins, even if bins are also included in the desired items list. Two solutions to this problem exist as of v0.40.24. First, bins can be disallowed in stockpiles that are linked to stops. Alternatively, bins '''can''' be used in conjunction with minecarts provided that the minecart's departure conditions use only "any items" instead of "desired items." This option can be toggled in the advanced conditions menu for a stop, accessible via the {{key|C|}} key. The cart's contents can still be controlled by specifying what items are allowed in the linked stockpile.

===== Departure condition =====
Departure conditions involve setting conditions in which the minecart will leave on the route. Each condition includes:
# A departure mode (Guide, Ride or Push).
# An initial departure direction (NSEW). Note that this defines the initial direction of movement only. Even if a track includes many turns, as long as the initial movement direction is valid the cart will follow the minecart track thereafter.
# A timer, before which the departure condition cannot be met.
# Conditions on the amount of items in the cart.
Departure conditions are created with the {{k|n}} key. A new departure condition will read: "guide north immediately when empty of desired items". This condition can be changed between basic presets with {{k|c}}. "Advanced" mode ({{k|C}}) allows for more precise control over departure conditions: fine tuning the percentage from 0 to 100 in 25% steps ({{k|f}} and {{k|F}}), switching it being either the maximum or the minimum amount of items for the condition to be met ({{k|m}}), and whether the cart accepts all or only a specific set of items ({{k|l}}). Common to both screens are the departure mode ({{k|p}}, Push, Ride or Guide), {{k|d}}irection, and timer ({{k|t}} and {{k|T}}) options.

To have a cart only carry a specific set of items, the stop can be set to only carry "desired" items, opening the selection screen with the {{k|Enter}} key while having said stop condition selected, and toggling as desired, or it can simply be linked to a stockpile and set to depart once it is full of items from its linked stockpiles, regardless of type.

=== Track Stops ===
A Track Stop, not to be confused with a route stop, is an optional, single-tile construction which serves two purposes. First, it can be used to cancel a cart's momentum in order to slow or stop it as it passes over the Track Stop. This might be necessary if a cart were pushed down a series of ramps to its destination. Second, a Track Stop can cause a cart to automatically dump its contents as it passes over the Track Stop. Track Stops are constructed via {{k|b}} {{k|C}} {{k|S}}, and must be constructed atop an existing piece of track. If a Track Stop has been set to automatically dump a cart's contents, the cart will dump its contents in the direction indicated when it passes over the Track Stop. Depending on the friction settings chosen for the Track Stop, the cart might then stop after dumping, or it might continue on its route to another destination.

Track Stops are not mandatory; in fact, their main use is in automated rail systems. However, even in basic rail systems it can be useful to set a Track Stop to dump items: this saves time that dwarves would otherwise spend in removing items from the cart, time that is better spent driving the cart back to where it's needed. Dumping will occur even with a guided cart. '''Take care not to set Track Stops at a loading site to dump their contents''', or dwarves will never be able to fill the cart. It will dump any contents the moment they are loaded.

Counter-intuitive to their construction method, Track Stops are considered [[building]]s and must be removed by {{k|q}} {{k|x}}.
* See [[#More_on_Track_stop |More on Track Stops]]

=== Step-by-step tutorial ===

Let's construct a simple minecart route. This route will move stone blocks from an input stockpile to an output stockpile. We'll begin by creating the stockpiles:

[[File:minecart-example-1.png|Stockpiles designated.]]

The input stockpile is on the left; the output stockpile is on the right. We'll be moving blocks from left to right. Disable bins in both stockpiles, and set the input stockpile to accept only from links. Then make the stockpile take from the mason's workshop where the blocks are being produced.

Next, carve the track:

[[File:minecart-example-2.png|Track carving designation.]]

Note that the ends of the designation are uniquely shaped; this is automatic, and not anything you need to control. Now, wait for your engravers to come along and carve the track into the stone. (Your haulers will probably also fill up the input stockpile while you wait.)

In addition, while we're waiting for that to happen, we'll build an iron minecart in the forge.

[[File:minecart-example-3.png|Track carved.]]

When the track has been carved, it will look like the above (the track will be solid instead of flashing). Now, order a track stop to be constructed next to the output stockpile:

{|
| [[File:minecart-example-4.png|Track stop designation.]]
| [[File:minecart-example-5.png|Select dumping direction.]]
|}

You must press {{k|d}} three times to select the dumping direction ''before'' placing the track stop. We want our blocks to be dumped into the output stockpile east of the track stop. Then wait for a mechanic to come along and build the track stop.

[[File:minecart-example-6.png|Track stop constructed.]]

Now we'll define the actual ''route''. This is done in the {{k|h}}auling menu. Press {{k|r}} to begin defining a route. Next, move the cursor to the input end of the track, and then press {{k|s}} to define the first stop:

{|
| [[File:minecart-example-7.png|Stop 1 designation.]]
| [[File:minecart-example-8.png|Route definition, in progress.]]
|}

Move the cursor again, to the output end of the track, and press {{k|s}} again to define the second stop:

{|
| [[File:minecart-example-9.png|Stop 2 designation.]]
| [[File:minecart-example-10.png|Route definition, two stops.]]
|-
|
| [[File:minecart-example-11.png|Stops are not defined yet.]]
|}

There are several user interface features to note at this point. The stops have been positioned, but they haven't been ''defined'' yet, so there is a warning {{DFtext|!|#ff0}} symbol by each of them. In the lower right corner, we see what the {{DFtext|!|#ff0}} means. Also, note that the second stop is labeled in white, while the other two lines are grey. The white text is a selection indicator, and can be moved up and down by pressing {{k|+}}/{{k|-}}.

Next we need to define what our stops do. We want the minecart to be filled with blocks at the first stop, then travel to the second stop where it will dump its cargo, and then return. Press {{k|-}} to move the selection up to stop 1, and {{k|Enter}} to open it up. By default, the stop has three conditions:

[[File:minecart-example-12.png|Default stop definition.]]

We don't want any of these, so press {{k|x}} three times to delete them. This leaves us with a blank stop. Now we can add the conditions we actually want. Press {{k|n}} to begin adding the first condition, then {{k|d}} twice to change the direction from north to east. Then press {{k|c}} to change the condition from empty to full. This will instruct the minecart to be guided east when full of desired items.

To set the desired items, we create a stockpile link. Press {{k|s}}, then move the cursor to the input stockpile, then press {{k|p}} to select that stockpile. Now press {{k|Enter}}; this opens up a selection screen that resembles the stockpile customization screen. Move down to Blocks, {{k|e}}nable them, then (if you wish) restrict it to stone blocks.

When you've done all that, stop 1 should look like this:

[[File:minecart-example-13.png|Stop 1, defined.]]

Stop 2 is much simpler. All we need to do is have the minecart return to the input stop. So, make a condition and change the direction:

[[File:minecart-example-14.png|Stop 2, defined.]]

Finally, we just have to assign our minecart. Go back to the route definition screen, and press {{k|v}}. Select the minecart, and press {{k|Enter}}.

Now we've got everything set up:

[[File:minecart-example-15.png|Route, fully defined.]]

The V is red because the minecart hasn't been moved onto the track yet. Some dwarf will have to haul it from the forge to the first stop, by hand; this will take a while, especially if the forge is far away.

Once the minecart is in place, dwarves should fill it with blocks from the input stockpile, which will in turn be filled with blocks from the workshop where your mason has been toiling dutifully. When the minecart is full, the blocks will be dumped into the 1x1 stockpile on the right. Automatic quantum dumping!

=== Troubleshooting ===

Because of the complexity of the system, all but the most careful and experienced minecart users will encounter issues. Most route issues can be diagnosed and fixed from the {{k|h}}auling menu.

'''Symptom:''' {{DFtext|! Set dir/connect track|6:1}} message appears to the right of one or more stops

'''Possible Causes:'''
* The departure direction of the stop might be invalid. Edit the stop using {{k|Enter}} and press{{k|d}} until it is pointing in a valid direction.
* The track stop might not be built on top of a track. The track stop must be deconstructed to remedy this issue.
* Your track might not be built correctly. Make sure all connected tracks between destinations are not one-way tracks.
** This can be especially confusing with ramps. To carve a two-way track on a (natural) ramp, you must designate the ramp and one square beyond in the direction you want the track to go.
** Ramps '''must''' have a solid block on the side opposite to the track, or they will neither work nor be marked as "unusable". The solid block can be natural or constructed.
* The desired/kept items might not be configured correctly.

'''Symptom:''' The status '''0% V''' always appears to the right of one stop.

'''Possible Causes:'''
* The stop may not be set to take from a stockpile. Edit the Stop using {{k|Enter}} and make sure you see a message like "Take from Stockpile #1".
* The take conditions must correspond with the contents of the stockpile.
* The track stop may be set to dump. A track stop set to dump cannot be filled. You must either set the stop to a time-based departure or deconstruct the track stop and rebuild it without dumping. (Alternatively, with [[DFHack]] you can modify "Dump on arrival" to "No" using the {{key|q}} menu without rebuilding the stop.)
* Make sure the minecart itself has not been designated to be dumped (such as when using mass-dump).

'''Symptom:''' Dwarves fill the minecart properly, but will not move it thereafter.

'''Possible Causes:'''
* The minecart may contain items which are not included in its current stop's desired items. Check inside the minecart using the {{key|k}} and {{key|z}} keys and ensure that all items in the cart are desired items.
* The minecart may contain desired items in bins. Minecarts seem to have problems realizing that they are in fact full of desired items if some of those items are in bins, even if bins are also among the desired items for that stop. '''This cannot be solved by adding the appropriate bins to the stop's desired items.''' Either disallow bins in stockpiles you intend to load minecarts from, or set the departure conditions to rely only on percentage of total load rather than percentage of desired items using the advanced conditions menu ({{key|C}} key).

'''Symptom:''' Dwarves repeatedly attempt to load the minecart, but no items are ever loaded into it.

'''Possible Causes:'''
* This can be caused by using a Track Stop with autodumping enabled at a loading site. Every time a dwarf places an item into a cart resting on such a track stop, the item will be immediately dumped, causing unlimited, useless cart loading jobs. Autodumping Track Stops should never be used at a loading site.

'''Symptom:''' A dwarf picks up the minecart and carries it to its destination.
* See [[#Quirks|Quirks]]

=== Danger ===
Minecarts are not without <strike>danger</strike> [[fun]]. Although designating a track automatically sets the [[traffic]] designation to low, dwarves ''may'' still walk on them, and [[creature]]s ignore traffic designations altogether. If an unlucky dwarf or creature fails to [[dodger|dodge]] a minecart, they can be injured. Most of this danger can be avoided by setting the minecart {{k|h}}auling commands to guide instead of push or ride (dwarves guiding minecarts will ignore traffic restrictions), as well as by [[pasture|pasturing]] domestic animals and preventing the access of other creatures to the tracks. Note that removing the track doesn't reset that tile back to normal traffic priority, so you may wish to manually clean up traffic designation afterward. Also note that bridges that are used as tracks don't have their traffic priority changed automatically (since they're just normal bridges), which could cause dwarves to pathfind normally through dangerous minecart entrances in your fort's walls if you're not careful.

The only <s>fool</s>''dwarf''-proof method is to make the tracks inaccessible. There are several ways to create a track which works for minecarts but doesn't allow creature-traversal; the simplest is perhaps building a [[statue]] on the tracks. Other options include adding single-tile holes (minecarts moving at reasonable speed will jump the gap), vertical drops, minecart-triggered doors, small pools of liquid (4/7 water or 2/7 magma), and hostile creatures overlooking the tracks. For safety, both ends of the track should be isolated, making the dangerous center sections completely inaccessible (though maintenance access can be provided by a locked door).

Danger does not always involve living victims: careless route designation can also result in minecarts careening off tracks or colliding with each other. If this occurs, the [[item]]s may be scattered; this can cause even more hauling jobs than the minecart aimed to eliminate. Even <s>better</s> worse, scattered items, especially [[weapon]]s, can injure passing [[dwarf|dwarves]] or other [[creature]]s; in the words of Toady One the Great, "Accidental grapeshotting of the dining room should be possible now."

Of course, the danger of using minecarts means they can also be [[Trap_design#Minecarts|used as weapons]] by imaginative players.

== Advanced usage and automation ==
Minecart-specific effects are implemented via track stops, rollers and [[pressure plate]]s with "track" condition set. Since all three are considered [[building]]s, they can't be built on the same square (however convenient track stop + pressure plate would be) nor a simple ramp, and are removed by {{k|q}} {{k|x}}.

=== More on Track stop ===
Track stops are constructions that allow further automation of minecart systems via adjustable features such as braking by friction and automatic dumping of contents. They can be built from logs, bars and blocks through {{K|b}} {{K|C}} {{K|S}}; friction amount, dumping toggle and dumping direction must be set '''before''' construction, and these settings can be neither changed nor seen thereafter; however, track stops can be linked to [[pressure plate]]s or [[lever]]s to toggle friction and dumping On or Off (trigger state is inverted: switch On = track stop Off).

If a [[stockpile]] is placed on the tile that a track stop is set to dump to, it can act as a [[Exploit#Quantum_stockpiles|quantum stockpile]] and any items dumped from a minecart that match the storage settings of the stockpile will remain there and accumulate. Normally trackstops are built on top of existing track to operate on moving minecarts, but they can also be used without tracks to create [[Exploit#The_Minecart_Stop|automatic quantum stockpiles]] (see also [[#Step-by-step_tutorial|step-by-step tutorial]]). It is not always desirable to collect ALL of certain items into one quantum stockpile, such as when distributing a material to multiple separate industries. You can link your quantum stockpile to various other stockpiles, ensuring that your dwarves will keep them supplied as necessary. Because quantum stockpiles never fill up like regular stockpiles, it may be a good idea to add a switch to turn them off.

Items dumped from a minecart at a track stop (or dumped by any other means) into open space fall through z-levels until they land on a solid surface. Items falling onto a designated [[stockpile]] will automatically be considered part of that stockpile, even if the stockpile is set to disallow those items (they will, however, be automatically moved to a more appropriate stockpile, if available). Items falling on top of a minecart will '''not''' fall "inside" the minecart. Use with caution; dwarves have fragile skulls.{{bug|5945}}

=== Automated propulsion ===
==== Roller ====
{{Main|Roller}}

A '''roller''' is a [[power]]ed [[machine component]] for the automated propulsion of minecarts. They are built over the top of existing tracks with {{K|b|M|r}}, requiring a [[mechanic]], ''(length/4)+1'' [[mechanism]]s and a [[rope]]. Rollers may also be placed directly on ramps to help pull carts up Z levels. Rollers are very useful to maintain a cart's momentum along long routes, to get them to climb Z-levels without dwarfpower involved, and to get them to reach speeds unattainable by guiding dwarves. These devices are variable-length (1-10), variable-direction and variable-speed ([[Minecart#Numbers_behind_the_scene|see below]]), all traits that can be set at construction time; a roller uses two units of power per tile it is long.

Single-tile rollers transfer power in all four cardinal directions, while other rollers generally only transfer power perpendicular to their activity direction. Longer rollers can also transfer power along their activity direction if built in the correct order, although this can be hard to accomplish and is easily broken. Rollers cannot be powered from above.

Rollers have great acceleration and capped speed. Carts going faster than the roller are unaffected. If a cart moves across an active roller in the direction the roller works and moves slower than the roller's specified speed, the cart will be set to the roller's speed. A cart going against a roller's movement direction will be sent back the way it came (once again at the roller's speed), unless it was moving extremely fast: speed increment of 100000 allows to reverse carts from the full "highest" (50000) speed roller to full "highest" speed back, but ramps can accelerate a cart beyond this. {{cite forum|144328/5702453}}
A cart crossing over a roller perpendicular to its current movement direction will gain the roller's amount of speed in the perpendicular direction without directly changing its forward motion. Without an adjacent wall to constrict its movement, this will typically send a cart off the rails on a diagonal path, completely unable to follow any tracks until it collides with a wall or is otherwise brought to rest. However, if the roller is placed over a track turn and pushes ''from'' the direction of that turn's track, the turn affects carts ''after'' the roller, so they will be forced into the turn rather than derailed in a diagonal direction. {{cite forum|144328/5702453}}

{{diagram|spaces=yes|\
tracks: full:
║ ║
═╗═ ═╢═
║ ║

╢ : roller pushing from W to E
}}
If the roller is powered, carts from ''all'' directions (unless too fast) exit S, because speed imparted by the roller forces carts toward E and ''then'' into the turn.
If not powered, carts from W and N exit S, carts from E and S exit W. Carts above derail speed will ignore the turn, of course.

{{diagram|spaces=yes|\
║ ║
═╗═ ═╟═
║ ║

╟ : Roller pushing from E to W
}}
Carts from the E or W: exit W.
Carts from N: derailed diagonally, exit SW.
Carts from S: derailed diagonally, exit NW.

Rollers affects carts on a track - if placed on a floor or ramp without any tracks, they are ignored. Depowered rollers are also ignored, friction is determined by the tiles underneath.

Because of their one-way nature, rollers are unsuitable for most two-way minecart tracks (unless you set gears toggling roller A->B off while toggling A<-B rollers on). However, a minecart set to be ''guided'' is not affected by rollers at all{{cite forum|109460/3286235}} — this allows a one-way track to be used in both directions. In addition, unpowered rollers do not affect minecarts.

Care must be taken in [[glacier]]s and other extremely cold [[biome]]s, since rollers (and the machinery used to power them) will not operate when constructed on natural [[ice]] floors.

==== Impulse ramps ====
Carts can be given momentum without rollers or changing z-level through a phenomenon called "impulse ramps". A track ramp which is connected both to a wall and to a floor will ''always'' accelerate a cart towards the connected floor tile, no matter where the cart enters the tile from. This means carts can be accelerated as though dropping z-levels, even if the cart doesn't actually change z-level at all. If a track ramp faces three directions such as ╩, then two of those directions need to be facing walls for the cart to be accelerated towards the remaining direction.

Example of straight impulse acceleration:

{{diagram|spaces=yes|\
▒▒▒▒▒▒▒▒▒▒ ▒▒▒▒▒▒▒▒▒▒
═▲▲▲▲▲▲▲▲▲▲═ ═╚╚╚╚╚╚╚╚╚╚═
▒ : Wall
═ : Normal track
▲/╚ : N/E Track/Ramp
}}

If a cart enters from the left, it will speed up on every track/ramp and exit to the right going very very fast - more than one tile every step. If it enters from the right then it will bounce back impulsed by the ramp if it's going slow enough.

As another oddity, carts coming from ramps will in some cases "teleport" through most of the next tile. This can be used to send carts up levels with minimal loss of speed. You can just make an upward spiral alternating impulse ramps and regular upward ramps. It takes no power, is quick and cheap to build, requiring only channeling and track carving, and the cart goes up fast, but not so fast that it launches its contents.

Example of an impulse elevator:

{{diagram|spaces=yes|\
z +0 z +1 z +2 z +3
░░░░░ ░░░░░ ░░░░░ ░░░░░
░╔░░░ ░▼╚╗░ ░░▼▼░ ░░░░░
░╝░░░ ░▼░░░ ░░░╔░ ░░░▼░
░▼▼░░ ░░░░░ ░░░╝░ ░╚╗▼░
░░░░░ ░░░░░ ░░░░░ ░░░░░

░ : Wall
╔,╚,╗,╝ : Track/Ramp
▼ : Down Ramp (empty space)
}}

Note that this impulse elevator, due to the checkpoint effect and upward ramp curve effect, will not actually result in carts traveling straight up the ramp. They will lose speed, bounce off a ramp, then be accelerated back into the spiral after a 9-turn delay on both tiles on the floor where they are stopped. This is because the checkpoint effect allows carts to travel up the ramps in a single turn, but also prevents the impulse ramps from adding acceleration unless the cart is slowed to staying on the ramp for more than one turn. Initial acceleration will carry the cart up a variable number of floors before this effect occurs, but this bouncing back and forth will occur every 5 z-levels after the first time the cart stops. When the cart ''is'' traveling upwards, it will pass every tile at a rate of one tile per turn regardless of its actual speed, due to the checkpoint effect. In tracks with only a single cart, this is negligible, but when multiple carts are on the same track (such as when you place multiple carts on a magma cart lift) this can cause collisions which derail carts or cause other unexpected or undesired behaviors.

The following impulse ramp (while larger) should alleviate these problems with additional impulse ramps that actually have enough time (more than one turn) to add speed (although a derail checkpoint may be required to prevent excessive speeds):

{{diagram|spaces=yes|\
z +0 z +1 z +2 z +3
░░░░░░ ░░░░░░ ░░░░░░ ░░░░░░
░░░░░░ ░╔╔═░░ ░▼▼▼╗░ ░░░░▼░
░║░░░░ ░▼░░░░ ░░░░╗░ ░░░░▼░
░╚░░░░ ░▼░░░░ ░░░░║░ ░░░░▼░
░╚▼▼▼░ ░▼░░░░ ░░░░░░ ░░═╝╝░
░░░░░░ ░░░░░░ ░░░░░░ ░░░░░░

░ : Wall
║,═,╔,╚,╗,╝ : Track/Ramp
▼ : Down Ramp (empty space)
}}

Also, if you want to have a cart following a regular speed, the following track works well:
{{diagram|spaces=yes|\
z +0 z +1 z +2 z +3
░░░░░ ░░░░░ ░░░░░ ░░░░░
░░░░░ ░══░░ ░▼▼║░ ░░░▼░
░║░░░ ░▼░░░ ░░░║░ ░░░▼░
░║▼▼░ ░▼░░░ ░░░░░ ░░══░
░░░░░ ░░░░░ ░░░░░ ░░░░░

░ : Wall
║,═ : Track/Ramp
▼ : Down Ramp (empty space)
}}
In this elevator, the cart collides with the walls in the corners, but then realigns on the ramp, picks up speed, checkpoints through the next ramp, and slams into the next wall. It is slower (10 ticks per floor) but produces reliable speeds, and will exit the impulse elevator at little more than push speeds.

A sort of opposite effect to impulse ramps also exists: ramps lacking the proper "up" and "down" connections are treated as flat track, even if they actually go up or down z-levels. This allows building "anti-impulse" slopes consisting entirely of ramps only connected up, which a minecart can travel up forty levels and more, needing no more than a single push.

=== Controlling traffic ===

==== Switching ====

As constructions or tile features, [[door]]s and other furniture can be built on tracks. A [[door]] or [[floodgate]] can be turned on or off by a [[lever]], effectively controlling the flow of automated minecarts. This may be <s>dangerous</s> [[fun]], however.
{{diagram|spaces=yes|\
->
A ════┤≡════ B
┤ : roller pushing to East
≡ : door
}}
The roller pushes the cart east, but until the "departure condition" is fulfilled, the door remains closed and blocks the path.

[[Bridge]]s can also act as tracks, but only if they're lowered or not retracted. This property can enable levers to turn tracks on and off. However, care should be taken to ensure that such bridges are never operated while a cart is on top of them, as the cart will be flung off the track. It's worth noting that it's often faster, and cheaper, to construct large bridges than long sections of constructed track.

A powered track switch can be constructed by building an "inverted" corner as illustrated below.
{{diagram|spaces=yes|\
B B
║ -> ║
║ ║
════╚═══ ════├════
A C A C
├ : roller pushing to West.
}}

If the cart is pushed East from the stop at 'A' while the roller is activated, it will arrive at 'B'. If the roller is not running, it will arrive at 'C'. The switch works by the roller first reversing the incoming cart's movement and the cart ''then'' following the track corner.

This switch is very reliable, reacts instantly to on/off signals, and carts of any speed can be switched by this design, although very fast carts will require rollers that are several tiles long, up to three. The requirement for power can be inconvenient or impractical. Non-powered solutions may use controlled derailment, or a connecting bridge.
{{diagram|spaces=yes|\
B ╥
║
║
╞════╝ ════╡
A D C
}}
Here the track between A and C is not continuous. The only continuous track is A->B, with a corner (not a T section). Fast moving carts will tend to derail at D and rejoin the track to C. Placing a door at D will prevent the derailment, so the cart continues to B. The door is operated by mechanisms elsewhere (typically, a lever, but some fun can be had with pressure plates).

Since it depends on derailing, this switch requires a very fast cart, faster than what can be achieved with rollers alone. To gain sufficient speed, a cart must be accelerated further, usually by descending several levels or through impulse ramps. The high speed makes the cart much more dangerous and harder to control.

If carts are moving too slowly to derail at the corner, a retractable bridge may be used as a connector between A and C.
{{diagram|spaces=yes|\
B╥
║
║
A╞════bbb════╡C
}}
The bridge must overlap the corner. Bridges behave like a track crossing, allowing carts to pass in a straight line. When retracted, the corner reappears, so the carts will continue to B. Bridges take 100 steps to react to a signal, necessitating rather long "lead times" when switching tracks via bridge.

As mentioned above, special care must be taken to make sure the bridge doesn't change state while the cart is passing over it. Retracting bridges will throw the cart, causing it to stop dead. Raising bridges can even crush the cart.

==== Controlling Speed ====


Minecarts can reach extremely high speeds, especially when descending multiple Z-levels. A minecart will derail at a track corner if its speed exceeds 0.5 t/st (tiles per step), '''unless''' the route in the direction of travel is blocked:

Will derail at > 0.5 t/st:

{{diagram|spaces=yes|\
in ══╗ -> derailing
║
out
}}

Will not derail at > 0.5 t/st:
{{diagram|spaces=yes|\
in ══╗O
║
out

O : wall/column.
}}

This behavior can be used to build a "speed limiter", that will ensure that when a minecart exits it is traveling below derail speed:
{{diagram|spaces=yes|\
░░░░ ░░░░░ ░░░░░
in ═╔═╗░ ░╔S╗░ ░╔S╗░
out ═╬═╝░ out ═╗═╝░ out ═╗═╝░
░╚S╝░ ░╚═╝═ in ░╚S╝░
░░░░░ ░░░░ ║░░░
in
░ : wall
S : Track Stop (High Friction or lower)
}}
If the minecart is traveling below derailment speed, it will not be affected; if above, will be slowed down and checked again. Granted, you could do the same just with track turns, but it may take a lot of turns and time.

Since all the derailings, bounces and ramps can impart a sideway component of speed small enough to start visible drift many tiles away (say, [[Fun|in the middle of a bridge]]), track turns have one more use: forcing the carts to move strictly along the grid directions. Carts passing a turn below derailing speed convert one component of velocity into another, thus eliminating the drift.

=== Loading liquids ===
[[Water]] and [[magma]] can also be loaded into minecarts by submerging them to a depth of at least 6/7 while standing still or moving at speeds of at most 10000. Loading fluids onto minecarts can be difficult because the added friction provided by fluids can stop a cart in a submerged tile. Curiously, filling a minecart with magma does not injure a dwarf ''riding'' it. A minecart will hold enough fluid to increase the depth of a single tile by 2. This amount is listed as 833 units, which weigh 459Γ (water) or 999Γ (magma). An iron or steel cart filled with magma weighs 1313Γ, while an adamantine cart filled with magma weighs 1007Γ. Since you need a minecart above the liquid's level, possible arrangements may include pressure-activated sluices, rollers (with magma-safe chains for magma), pouring from above to "submerge" it briefly on the same level and drain excess away (dig deeper and leave a vaporizer, though if you could have power for rollers, may as well use a pump) and exploits with ramps (not necessarily impulse ramps, "same height" passing dip does it).
The liquids can be dumped by a constructed track stop.

== Quirks ==
This little quirk concerns dwarf-managed minecarts. If a track which was previously open becomes blocked (ex. flipping a switch connected to a floodgate you've built on the track to raise it) and the conditions for departure are met, instead of refusing to ride/guide the minecart or ride/guide it until it reaches the obstacle, the dwarf will pick up the minecart off the tracks and haul it to its scheduled destination on foot. If the distance is long enough and the weight of the cart heavy enough (due to being filled with heavy items such as stones), the dwarf may drop the cart because of fatigue/hunger/thirst before reaching the destination. This will cancel that vehicle setting job and make another dwarf come by and attempt to haul the cart to the nearest appropriate stockpile where another dwarf will pick up the cart and attempt to haul it to its initial stop. If the stockpile is far enough from initial stop, this second dwarf who is attempting to place the minecart on its tracks may also drop the minecart out of fatigue/hunger/thirst creating a loop that will go on until a dwarf with enough endurance manages to place the minecart where it belongs.

In fact, it seems dwarves are more than happy to attempt to carry a minecart from one stop to another even if just waiting until the track is open again would be the more sane option.

Dwarves will also carry a minecart to its next stop if the direction specified is incorrect (or invalid). This can often occur when using the default departure settings and forgetting to set the direction of each condition.

Dwarves can admire buildings while riding mine carts. Dwarves will not fall asleep during a ride (at least not from being drowsy). If riding on a continuous powered track loop, the dwarf will die of dehydration/starvation as they can not jump off to get sustenance{{cite forum|109460/3377228}}. Dwarves riding in submerged minecarts will gain experience in [[swimming]].{{cite forum|129889}}

Tracks block wagon access to trade depots, unless they're on a ramp. [[Bridge]]s can also be used, as they function as tracks but do not block wagons.

== Physics ==


Minecart physics depend greatly on the departure mode set in the route stop conditions.

When set to "Push" or "Ride", minecarts will move according to the regular laws of momentum, gaining speed when going downhill, losing it slowly due to friction when on a flat plane, and more quickly when going uphill. In these modes, minecarts will move in a straight line until they either are brought to a stop by friction or an obstacle, or until they encounter a turn. A minecart will roll straight past "blocked" ends of T-junctions or track ends, they have no power to restrict a cart's movement. The cart's behavior is largely independent of the weight of its contents (including fluids and dwarves): heavily loaded carts gain more momentum when accelerating, but this only plays a role in collisions: a heavy cart gains just as much speed and is as easy to stop as a light one. In either case, dwarves can not push nor ride an unpowered cart up a ramp, bouncing back the direction it came. At best, this is a waste of time; at worst, it will give your cart-pushing dwarf a [[fun|fun surprise]]. To solve this, the player can either use Rollers (see below) or set the cart to be Guided.

The difference between "Push" and "Ride" is whether the dwarf will go along with the cart or not.
{{DFtext|Push}}: the dwarf will give the cart an initial push, not enough to go up a ramp, but enough to go some way along flat track, and the dwarf will remain at the first stop, ready for a new job.
{{DFtext|Ride}}: the dwarf will give the cart the same initial push and then hop aboard the cart riding with it to the next stop.
{{DFtext|Guide}}: minecarts seem to ignore all laws of physics. That is:
*Ignore the weight of any and all items inside. Therefore:
**Move at the speed of the dwarf that is guiding them. It is thus recommended to pick the most [[attribute#Agility|agile]] of your dwarves for cart-guiding tasks.
*Ignore working rollers.
*Will ''not'' collide with other guided carts even when a full frontal collision would be expected.
*Will go up ramps like nobody's business.
This is therefore the recommended method of transport for simple non-powered rail systems, despite it diverting a dwarf from other, potentially more important tasks.

Some samples with behavior:
{{diagram|spaces=yes|\
A <-> B A <-> C A <-> B
B B B
║ ║ ║
A══╝ A══╩══C A══╬╗
You can only go A->B ╚╝
Works when the cart Works
is in Guide mode.
}}
In the second example above, a cart "pushed" from B will go over the junction and roll off into the unknown south.

=== Track Direction Irrelevance ===
Carts that are traveling independently, (that is, not guided,) only care that tracks ''are'' on the tile, not which direction the tracks actually move. Tracks respect only curves (with two exits) and ramps.

This means, for example, that the following tracks, when a (non-guided) cart travels from West-to-East, are functionally identical in effect:

{{diagram|spaces=yes|\
A════════════B A╬║╚╔╣╩╦╠╥╨╞╡B
}}

This is because so far as the cart is concerned, only ramps and curves with two exits where the exit in the path they are traveling matters.

Hence, if a minecart encounters the end of the track or a T junction with no "exit" in its movement direction, it will simply leave the track and continue on its course in a straight line until it encounters an obstacle, slows to a stop, or encounters another track even if the tile at which it joins the new track instantly sends it around a corner.

In fact, a "║", a "╦", a "╬", and a "╥" are ''only different in appearance'', and are ignored by the cart, which will continue in its current direction, regardless of the track.

Carts only check for curves when they are halfway through a tile. When they get there, they look to see if their path has no exit. (That is, if it is traveling East, it checks if there is an East exit.) If there is, it ignores all other track directions, and keeps traveling. If there is not, it checks to see if there are only two exits to the track, and if one of those directions was the direction it "came from". (That is, if traveling from the East, it checks if there is a valid exit to the West, and if so, if there is either a North exit or a South exit.) If there is not, it ignores the track anyway, and keeps on traveling as though it were still on track. If there is, it will subtract 1000 from the velocity of the cart, and redirect all forward velocity to the direction of the curve. This change in the direction of velocity ''overwrites'' any "diagonal" velocity, which can prevent diagonal velocity derailments, but any perpendicular velocity is not preserved, and is instead discarded.

=== Valid and Invalid Ramps ===
Ramps are functionally defined for cart purposes as being a tile which exerts an acceleration force upon its "downward slope", and which allows connection to tracks a z-level above or below. This downward slope requires a cart to have one ''and exactly one'' carved exit to the tile that is the "bottom" of the ramp. Ramps accelerate carts in this "downward" direction (possibly leading to diagonal movement, below), and the deceleration of an "uphill" ramp is actually just the acceleration being applied against the direction of a cart's movement.

This is where players can find an exploit in the behavior of ramps - if there are ''two'' "downhill" exits to a ramp (such as a "T junction" on a ramp where only one exit faces a wall), then the ramp provides no acceleration ''or'' deceleration, allowing carts to travel up ramps without any loss of momentum except for the standard "flat track" deceleration, because as far as the cart is concerned, the track ''is'' flat. (A T junction is also not a curve, so the track is considered flat and straight no matter what direction the cart is traveling.)

Similar effects can be achieved when there are ''no'' "downhill" exits to a ramp. This may be the case if you have, for example, an East-West track with a one-tile channel with a ramp in it. The cart will travel through the "dip" with no change in velocity. It can also be the case if you abuse the Track Direction Irrelevance, above, and set only exits ''up'' the ramp, and none leading ''down'' the ramp. For example, if a cart is traveling from West to East up a slope, only carving East exits on each tile of ramp will make the cart travel up the ramp, and then recognize the tile it is on as being a "flat" tile, thus ignoring any deceleration from traveling uphill. Note that this effect only reliably occurs at relatively slow speeds (at around push, or single accelerating ramp speeds) as the cart may simply ignore the ramp and crash into the wall at higher speeds.

=== Falling ===
When falling, a minecart appears to cause no damage upon collision, possibly to allow cart "stacking" across Z-levels.{{cite devlog|2012|04|06}} A dwarf riding in a minecart that is dropped multiple z-levels suffers normal fall damage. Minecarts can fall through up/down stairs.

While airborne, carts do not feel the effects of friction in any horizontal direction, and will continue until they strike an obstacle. Carts that land on tracks instantly re-rail themselves regardless of track directionality.

Falling carts accelerate similarly to the way that a ramp will accelerate a cart in a special z-only velocity that only applies to airborne carts. (Actually, acceleration due to gravity in freefall seems curiously slightly ''slower'' than ramp acceleration.) Ramp acceleration, while it logically should be partially z-directional, is only recorded as x- or y-directional, and there is no translation of z-directional velocity upon landing. Landing carts zero out their vertical velocity upon landing, even when landing on ramps, although carts that had horizontal momentum while falling preserve it.

This means a cart falling (from a hatch, thus with no horizontal speed) onto a track ramp is accelerated as if starting from the middle of the ramp - i.e. to the same speed, no matter how many Z-levels it was dropped, vertical velocity is negated. {{cite forum|144328/5701211}}

Carts falling onto a floor can, however, cause damage to creatures ''one tile below the floor''. This can be used in an [[exploit]] called a "thumper", where carts are caused to repeatedly fall on a floor above an entrance to the fort, inflicting significant damage (as though it were a collision) on those below the cart.

=== Cart Jumps ===
Carts that cross off of "up" ramps relative to their current direction of travel, which do not have a ceiling above them, and do not have valid ramp track before them can translate a portion of their horizontal velocity into vertical velocity, causing a cart to be projected into the air until vertical velocity is negated and overcome by the gravitational acceleration. Because downwards acceleration is applied per-tick, this creates a reasonable facsimile of the parabolic motion of an actual object rolled up a ramp and launched with significant speed.

{{diagram|spaces=yes|\
z0 z0 hiding ramps z+1 A z+1 B (hidden ramp)
▒▒▒▒▒▒▒▒▒▒▒▒ ▒▒▒▒▒▒▒▒▒▒▒▒ ▒▒▒▒▒▒▒▒▒▒▒▒ ▒▒▒▒▒▒▒▒▒▒▒▒
═▲▲▲▲▲══▲▒▲═ ═╚╚╚╚╚═══▒══ ▼▼▼▼▼ ▼═▼ ▼▼▼▼▼ ▼╚▼
▒ : Wall
═ : track
▲ : Ramp
}}
In this diagram, if there is no ceiling above it, the track in z+1 A will launch its carts airborne when they travel across the ramp. z+1 B (with a ramp on the tile on the hill) will not launch the cart. The cart would also not be launched with ''any'' valid ramp, even if it does not travel in an appropriate direction, such as North/South (which the cart will ignore, as it is not a curve, anyway, although it may produce acceleration that may cause diagonal movement.)

Tracks that are travelling at high enough velocity will also start "jumping" from track if it hits an un-tracked tile (flying over and ignoring any tracks) until it is ready to land. Carts that land upon tracked tiles re-rail themselves, and clever designers use this feature to jump over curved track sections in one direction or another. (Retracting bridges over untracked tiles can cause jumps or not cause jumps depending upon the status of the bridge.) Minecart speed must be carefully regulated to ensure reliability of jump length.

This creates a vertical component to acceleration that allows for jumps of around 6 (horizontal) tiles that do not actually leave the z-level the cart is on, but which do apply z-direction velocity on the cart, as per falling.

Carts that approach a downward slope at a high enough velocity will also make a jump, but will not do so if the Checkpoint Effect (below) is exploited through an impulse ramp before the actual downhill as the impulse ramp "tricks" the cart into thinking it has already started going downhill.

=== Skipping ===
If a minecart is moving fast enough, it can skip over [[water]] or [[magma]], making splashes of [[mist]] (or [[magma mist]]) as it attempts to move on them horizontally. This horizontal movement is independent of the minecart and its content's [[weight]].

Skipping causes significant friction on the cart, and even a cart going at max speed from ramps can only make about 50 tiles without requiring re-acceleration. (Carts that decelerate enough that they do not trigger the skipping effect will, of course, sink.)

=== Corner Ramp Derail ===

Corners on upward ramps can cause diagonal movement, forcing a derail even if the cart has a wall next to it, which will force a stop when it touches a wall that forces dwarves to manually reset the cart.

This is caused by the fact that a cart, after turning the bend in the track halfway through the length of the tile, will still "accelerate down", which is now perpendicular to the movement of the cart, causing acceleration to occur in two directions. (Down corner ramps do not have this problem, as when they pass the halfway point, all perpendicular motion is added to forward motion, and after that curve, all downward acceleration is in the forward direction.)

There are two fixes to this problem. One is to simply not put corners on up ramps. The other is to take advantage of the Checkpoint Effect, below, by making a ramp (possibly including an impulse ramp) one tile in front of the ramp to make it skip through most of the tile before sideways momentum can be built.

=== Checkpoint Effect ===
The checkpoint effect, [http://www.bay12forums.com/smf/index.php?topic=144328.0 explained in depth by Larix], is an odd and highly exploitable feature of ramps where minecarts "teleport" through the next tile of track, ignoring nearly all minecart physics (except that they stop at all walls or other obstacles and not only respect curves, but will take them even when they would otherwise derail) and passing through that tile in just a single tick, and into the next tile at the halfway point.

This effect occurs when a cart leaves a downward ramp for any other direction of tile. (This includes ramps which accelerate in different directions, even a ramp which goes from accelerating East to accelerating North due to a bend in a chain of standard down ramps in a curve.) This allows, for example, two valid straight ramps directly next to one another with a cart dropped onto one or the other with no momentum to have the cart pick up acceleration going "down" the ramp as normal, but then flying up through the "up" ramp it travels into with no loss of momentum, as though it had come from an impulse ramp. If the two ramps had at least one space of distance between them, and then a cart were dropped in, the cart would instead "rock" back and forth between the two ramps.

This seems to be because ramps have a slightly longer length than regular tiles - 144,000, rather than 100,000 distance. When this "snaps back" after a ramp, it seems to project the cart suddenly further along the track, making it jump a tile ahead even when otherwise moving at relatively low speeds.

This [[bug]] is the cause of a ''wide array'' of unexpected behavior among people who do not take this bug into account. It causes derailments or failure to climb up seemingly valid impulse elevators. In general, it makes a system that behaves extremely counter-intuitively, and operates ''any time a cart encounters a valid ramp''. At the same time, when its effect is accounted for, it is highly exploitable: It causes "perpetual motion devices" using no power when two opposing ramps are placed next to one another, since the "uphill" effect of the opposing ramp is ignored, preventing deceleration.

Another useful thing to note about this exploit is that carts traveling at no less than 72,000 or so speed (enough to travel half a ramp tile in a single tick) can travel through every tile in just one tick at no change in velocity as long as the tiles alternate between impulse ramp or actual down ramp and any other tile type. The cart checkpoints through the non-down-ramp tiles, and can pass through the (impulse) down ramp tiles in a single tick, before they can actually start gaining momentum.

{{diagram|spaces=yes|\
▒▒▒▒▒▒▒▒▒▒ ▒▒▒▒▒▒▒▒▒▒
═▲═▲═▲═▲═▲═ ═╚═╚═╚═╚═╚═
▒ : Wall
═ : Normal track
▲/╚ : N/E Track/Ramp
}}

If the cart enters from the West at less than 72,000 speed, some of those ramps will cause Eastward acceleration.

This means that an impulse ramp not contiguous to other impulse ramps has a top speed of around 75k:

{{diagram|spaces=yes|\
▒▒▒▒▒ ▒▒▒▒▒
▒╔═╗▒ ▒╔═╗▒
▒╚▲╝▒ ▒╚╗╝▒
▒▒▒▒▒ ▒▒▒▒▒
}}
This setup makes a cart that travels clockwise at a speed that fluctuates around 75k velocity. If the cart has more than 72k velocity, it fails to accelerate in the ramp, as it leaves the ramp in a single turn due to checkpointing to the halfway point. After that, the curves sap 1k velocity, and every tick saps 10 velocity.

Two contiguous impulse ramps with a same-facing "downwards slope", however, do not suffer the checkpoint effect in the second tile, giving functionally triple the space to accelerate. This means it will add velocity (at the standard rate of 4.9k per tick) up to a maximum speed of 216k.
{{diagram|spaces=yes|\
▒▒▒▒▒▒ ▒▒▒▒▒▒
▒╔══╗▒ ▒╔══╗▒
▒╚▲▲╝▒ ▒╚╗╗╝▒
▒▒▒▒▒▒ ▒▒▒▒▒▒
}}
This example results in a cart moving three times as fast as the previous cart.

Three successive ramps results in the highest attainable speeds.

In practical terms, this means that only consecutive ramps should be used for high acceleration, but singleton ramps can be used to have speeds that are somewhat regulated.

=== Stacking ===
If a minecart lands on top of another minecart, they may form a stack, with the upper cart on the z-level above the lower. Subsequent carts do not form a stack, but rather quantum stockpile in the same space. This behaviour is useful for [[megaprojects]] and [[trap design]] with minecarts as the weaponry. Moderation should still be exercised: carts take longer to fall into a "stacking" tile already occupied by other carts and will spend that time "hanging" in the air above the stack. This can lead to following carts striking them, which can cause all kinds of malfunctions. The extra time is two game steps for every cart already in the stack, which doesn't hurt stacks of ten carts very much but makes stacks of 100+ rather impractical.

These minecarts on the upper level generally need to be struck with another minecart to move out, or have their support removed. The latter option is safest done by shooting it away with another minecart, manual removal of a stack-supporting cart typically causes the next cart from the stack to [[fun|fall on top]] of the hauler.

=== Perfectly Elastic Collisions ===
Minecart collisions are perfectly elastic, meaning that not only do minecarts not take damage, but that two carts that are rolling which have frontal collisions of near-similar speed, and where one cart is no more than twice the mass of the other cart, will result in a billiard-ball-like effect of the lighter cart bouncing off the heavier cart with a proportional speed increase dependent upon the relative momentum behind the heavier cart.

Using this trick with carts already at the 270,000 maximum speed from ramps can result in "supersonic" carts traveling at speeds in the millions (travelling a dozen tiles per tick), but where they are suddenly subject to 10,000 units of "terminal velocity" friction per tick. [http://www.bay12forums.com/smf/index.php?topic=137557.0 Thread with SCIENCE here].

While hypothetically capable of launching a minecart into orbit when used in conjunction with a ramp, no cargo can be contained in the launched cart, as the collisions will force ejections of the cargo. Your "unwilling volunteer" [[goblin]] space pioneers will simply become paste underneath the wheels of an extreme high-speed cart.

=== Numbers behind the scene ===

According to early research by '''expwnent'''{{cite forum|112831/3536975}}:

The minecart has a variable for speed. Speed is measured in tiles/100000 ticks, so a speed of one hundred thousand means one tile per tick. By going down a large number of ramps, a maximum speed of 270,000 can be reached, which presents the limit for most practical applications. Short bursts of (much) higher speeds are possible through carefully planned collisions of high-speed carts {{cite forum|137557/5145499}}.

Every tick the cart accumulates distance units, as well as slows down depending on current tile (speed is reduced by "friction" of the tile). The cart will move to the next tile the tick before accumulating 100000 distance units, (or several tiles in case of great speed), then the leftover distance units are added to the default 100000 distance u. of the next tile. Since most deceleration and acceleration is applied per step, with the notable exception of corners, a cart going at twice the speed of another one can cover about four times the distance in a straight line, but only twice the distance along a winding track with very many corners.

A push will teleport a cart to the beginning of the next tile (NOT the middle!) in one tick with 19990 speed (10 speed is lost due to track friction), while a roller will give a cart the roller's set speed, and it will start to accumulate regular track friction past the middle of the roller tile. Some track features will affect a minecart when it is past the middle of the previous tile: entering a ramp or a hole/drop will happen when the cart has left the middle of the previous tile, and the ramp will gain additional distance unit depending on the leftover units from the previous tile. When a cart leaves a ramp it will emerge after one tick in the middle of the next regular tile, so its entry coordinate is "50000-speed+friction". Rollers also affect the speed of minecart from the middle of the previous tile.

Friction of tiles:
{| class="wikitable"
|-
! Tile
! Friction
! Comment
|-
| Tracks
| 10
|-
| Ground/Floor
| 200
|-
| Unusable ramp
| 10
|-
| Upwards ramp
| 4910 (10+4900)
|-
| Downwards ramp
| -4890 (10-4900)
|-
| Roller
| ±100000 (but capped by the set speed)
|-
| Corner track
| 10
| Speed reduced by 1000 upon leaving the corner tile
|-
| Track stop (highest)
| 50000
|-
| Track stop (high)
| 10000
|-
| Track stop (medium)
| 500
|-
| Track stop (low)
| 50
|-
| Track stop (lowest)
| 10
|-
| Water 1-6
| Additional (WaterLevel - 1) * 100
| rowspan="2" | [[#Skipping|See Skipping]]
|-
| Magma 1-6
| Additional (WaterLevel - 1) * 500
|-
| Empty space
| 0
|}

Water of depth 7/7 provides a friction of about 10000 per step, as does maximum-depth magma. This higher friction may not apply to very slow-moving carts.

Impulse sources:
{| class="wikitable"
|-
! Feature
! Speed
|-
| Push
| 20000
|-
| Roller lowest
| 10000
|-
| Roller low
| 20000
|-
| Roller medium
| 30000
|-
| Roller high
| 40000
|-
| Roller Highest
| 50000
|-
|}

== Non-standard uses ==
Minecarts include some interesting characteristics that have motivated uses beyond hauling. They can be useful for creating fully-automated [[exploit|quantum stockpiles]] and [[garbage disposal]]s. Storing perishable goods (meat, meals, etc.) inside a minecart appears to guard against rot and vermin.
Minecarts can be [[Trap_design#Minecarts|used as weapons]], or as (hopefully non-fatal) triggers to restart stalled [[healthcare]]. They can also be used to time/control game events, either using a basic [[repeater]] or much more advanced [[minecart logic]].
Minecarts trigger [[pressure plate]]s, which means a trap can be designed to trigger when a thief attempts to steal a minecart.
A pressure plate can be used as automatic and more precise custom "launch when full enough" system - as long as weight of your minecarts stays the same. You cannot build a hatch or roller on the same tile, so launch by bumping with another cart. {{cite forum|15096/4580050}}
Dwarves riding minecarts can attack enemies within reach (which goes back to dev log). This applies to shooting, and they actually can hit targets while riding by.{{cite forum|109460/5266119}} Whether a minecart protects the rider and how it interacts with dodging is not known yet. Minecart riders can also [[Swimming#Minecart_training|train swimming]] and [[Megaprojects#Surveillance_Track|detect ambushers]].

== Adventure mode ==
In addition to being used for hauling, minecarts can also be ridden in [[adventure mode]]. (Adapted from forum thread {{cite forum|122903/4258212}})

# If the minecart is in your inventory, drop it. If it is already on the ground, proceed to step 2.
# Press {{k|u}} when you are 1 tile away from the minecart (or standing on the same tile as the minecart).
# You will be presented with the following options:
[[File:minecart adventure mode menu.png|left]]
{{clear}}
* If you {{DFtext|Push}} the minecart, it will move a few tiles in the direction you chose. Physics comes into play here, so it will gain/lose speed depending on the usual factors.
* If you {{DFtext|Ride}} the minecart, you will hop into the minecart, even if you were a tile away, and it will move in the chosen direction with you in it. It will gain/lose speed depending on the usual factors. Whilst the minecart is in motion, you should press {{k|.}} to skip your turn; if you attempt to move whilst the minecart is still in motion, the laws of physics come into play, and you will take [[wound|damage]]. Alternatively, you can push the minecart whilst it's still in motion (although it's unclear how one can bend [[physics]] so as to push a moving minecart whilst inside the minecart). If you push it in the same direction you are already travelling in, you will greatly increase the minecart's velocity. You can also push it in different directions, and this will cause it to gradually change direction-the amount of pushes this requires depends on the minecart's velocity. Once the minecart has stopped moving, you may move out of it safely, or you may want to give it another push. Note that if you push a minecart right after having ridden it (still on the same tile as the minecart), it will act as though you chose to ''ride'' it.

If you want to test this out without creating an adventurer, the [[object testing arena]] allows you to spawn minecarts ({{k|k}}-{{k|c}}-{{k|n}})

== Forging and Melting ==
* Metal minecarts cost '''two''' [[metal]] bars to forge, or '''six''' [[adamantine]] wafers.
* When a non-adamantine metal minecart is melted down, it will return '''1.8''' metal bars, for an '''efficiency of 90%'''.
* When an adamantine minecart is melted down, it will produce '''1.8''' wafers, for an '''efficiency of 30%'''.

== See also ==
* [http://www.bay12forums.com/smf/index.php?topic=109460.0 The "How Does Minecart" Thread] by '''Girlinhat''' et al.
* [http://www.bay12forums.com/smf/index.php?topic=112831.0 SCIENCE: Quantifying minecart physics] by '''Snaake''' et al.
* [http://www.bay12forums.com/smf/index.php?topic=129676.0 How to build a Multi-cart Ore to Magma Minecart Project without needing power] by '''WanderingKid'''.
* [http://www.bay12forums.com/smf/index.php?topic=144328.0 My very own Minecart Education Thread. Ten Lessons, now complete.] by '''Larix'''.

== Bugs ==
*A dwarf will drop her [[child|baby]], if she has one, when boarding a minecart set to be ridden.
*Dwarves have no concept of traffic safety and will walk into busy minecart lines to retrieve objects, often with deadly consequences. This is especially problematic in [[Swimming#Minecart_training|clever applications]] depending on dwarves riding the carts very frequently, because they have a bad habit of dumping their worn clothes on the tracks after a minecart ride. Adding an automatically-operated [[hatch cover]] at the end of such a ride can help prevent [[unfortunate accident]]s.
*Dwarves cannot guide a minecart through an unlocked door unless another dwarf opens the door.{{bug|6056}}
*It is possible for a creature and minecart moving towards each other to pass without collision if they exchange tiles in the same tick.
*After a minecart ride, a dwarf will sometimes haul the minecart to a storage stockpile, leaving another dwarf to haul the vehicle back to the route.
*Minecarts falling onto a floor injure creatures in the tile below the floor.{{bug|6068}}
*A minecart's initial velocity is not affected by weight, when pushed or launched from rollers.{{bug|6296}}
*Removing a stop that has a vehicle waiting on it may cause the game to crash.{{bug|5980}}

{{Category|Fortress mode}}
{{Category|Interface}}

[[ru:Minecart]]

Minecart

2015-06-18T17:51:37Z

NW Kohaku: /* Impulse ramps */ Correcting for checkpoint effect

{{Quality|Masterwork|08:15, 19 May 2015 (UTC)}}
{{av}}
A '''minecart''' is a [[tool]] intended for [[hauling]], introduced in version 0.34.08. It can be made of [[wood]] at a [[carpenter's workshop]] or [[metal]] at a [[metalsmith's forge]] (using the [[Metal crafter|metalcrafting]] labor.) Minecarts store up to five times as many items as [[wheelbarrow]]s and are quite a bit faster than dwarves hauling objects by hand, but have the disadvantages of requiring a dedicated track network, a complex route planning phase, and the possibility of dwarves [[Fun|blundering into the path of carts filled with lead ore]]. Tracks may be carved into stone, or [[Construction|constructed]]; the latter allows above-ground routes, but these are more difficult to set up due to their additional [[building material|material requirements]].

Just like wheelbarrows, minecarts are considered [[item]]s and are stored in a [[furniture]] [[stockpile]]. Despite their five-times-greater capacity, they are only 33% larger than wheelbarrows and are identical in base [[item value|value]] when made from the same [[material]] (the value may differ due to the [[item quality]]). [[thief|Thieves]] or even mischievous animals can steal minecarts, even when they are moving on a track{{cite forum|109460/3289070}}. However, minecarts moving fast enough or being ridden cannot be stolen.

Although most of the utility of minecarts is in [[fortress mode]], an [[adventure mode|adventurer]] can also ride in a minecart. Adventurers can also pick up and relocate minecarts.

The invention of minecarts revolutionized the [[minecart logic|Science of Dwarfputing]] by enabling smaller, faster logic systems to be built.

== Basic Minecart Usage ==
Minecarts can be used to swiftly transport dwarves, [[flow|fluids]], and/or large amounts of items, but before you have a functional minecart there are several preconditions that need to be met. First of all you need an actual minecart, constructed either in a [[carpenter's workshop]] or [[metalsmith's forge]]. For the minecart to be able to move you also need to carve (with {{k|d}} {{k|T}}) or construct (with {{k|b}} {{k|C}} {{k|T}}) a track, which could be as simple as a straight line. Finally you need to construct stops on your track (with {{k|b}} {{k|C}} {{k|S}}) where the minecart will start and stop.

After you have created the stops and assigned a cart to the track, you must create logic routes connecting several stops and designate starting conditions for each stop. This is done with the {{k|h}}auling key. The most basic conditions are how the cart's movement is initiated and in which direction the cart should start moving. Carts can be either be Pushed (a dwarf stands at a stop and gives the cart a single push) or Guided (a dwarf continually pushes the cart forward, guiding it along the track). The [[hauling]] [[labor]] required for pushing and guiding carts is called "Push/Haul Vehicles" and is turned on by default.

To control which items to transport you can add conditions specifying: (1) which kind of items to be loaded, and unloaded, (2) stockpile links to define which stockpile(s) the items should be un/loaded to and from.

===Capacity and weights ===
Minecarts have five times the [[Weight|capacity]] of [[wheelbarrow]]s.

'''Examples of the capacity of one cart'''
{| class="wikitable"
|-
! Item
! Amount
|-
| [[stone]]
| 5
|-
| [[wood|log]]
| 10
|-
| [[block]]/[[bar]]
| 83
|-
| [[Kitchen|prepared meals]]
| 500
|-
| [[Trap_component#Spiked_ball|spiked balls]]
| 500
|-
| [[Weapon#Native_weapons|mace]]
| 625
|-
| [[Weapon#Native_weapons|spears]]
| 1250
|-
| [[cloth]]
| 2500
|}

The weight of the loaded minecart does not affect the initial velocity received from pushing or launching from a roller. However, the load of a minecart ''does'' affect whether a [[pressure plate]] triggers or not, based on the pressure plate's setting.

'''Weights of different carts'''

{| class="wikitable"
|-
! Type of cart
! Empty cart
! Fully loaded (items)
|-
| oaken minecart
| 28Γ
| 378Γ (10 oak logs)
|-
| platinum minecart
| 856Γ
| 10482Γ (83 gold bars)
|}

The weight of a minecart is one twenty-fifth (1/25) the [[density]] of its material in Urists. Because pressure plates can be set to trigger at intervals of 50 Urists, minecarts with weights just under a multiple of 50 are ideal for switching based on whether they're full or empty. The best minecart materials for full/empty switching are as follows:

{| class="wikitable sortable"
|-
! Material !! Minecart weight !! Content weight required to trigger !! Banana roasts required to trigger (for scale)
|-
| [[Bismuth]] (moods only) || 391 || 9 || 15
|-
| [[Brass]] || 342 || 8 || 14
|-
| [[Electrum]] || 596 || 4 || 7
|-
| [[Fine pewter]] || 291 || 9 || 15
|-
| [[Glumprong]] || 48 || 2 || 4
|-
| [[Lay pewter]] || 291 || 9 || 15
|-
| [[Nickel silver]] || 346 || 4 || 7
|-
| [[Tin]] || 291 || 9 || 15
|-
| [[Trifle pewter]] || 291 || 9 || 15
|}

=== Creating tracks ===
Minecart tracks are made up of contiguous track, tracked ramp, or bridge tiles. Track tiles and tracked ramp tiles have a direction or series of directions associated with them. These directions dictate which directions a minecart on a given tile may move from that tile. For example, a Track NE (northeast) tile allows a minecart on it to move either north or east from its present position. Therefore, if you want your minecart to move east along a straight piece of track, then return west using that same track, you would need to use EW tracks so that the cart could travel east initially, then return west over the same track. Excluding designs in which the cart will "jump" tracks via a drop or other ramp, tracks must be valid end to end to work for most looped or straight-track applications. A single east only track tile in your line of east-west tracks will cause any route using the track to fail the moment it tries to go the wrong way over that tile. Minecart tracks can be built in two ways: Engraved/carved or constructed. A given minecart track need not use engraved or constructed elements exclusively, as the two methods can be used interchangeably depending on the needs of a given section of track. The way the tracks are built is slightly different between the two, as explained below.

====Simple tracks====

'''Carved'''

A single-tile wide strip of natural stone can be designated to be [[Engraver|carved]] (with {{K|d}} {{k|T}}), which will create a straight two-way track. The creation of corners, crossings, and T-junctions is as simple as designating another strip of track that overlaps an existent or newly designated track. Engraved tracks are removed by [[smoothing]] the rock they're on, which results in a smooth floor (that can be re-engraved if necessary), or by building a [[floor]] on top and subsequently removing it. Dwarves can carve corner tracks in one pass by designating the track carving twice and canceling unwanted carvings (with {{K|d}} {{K|x}}). Tracks can be engraved in any natural floor tile, rough, smooth and even over engravings, providing an easy method to remove low-quality or undesired floor engravings. Once a track has been engraved, it's important to check the track directions for each tile in the route carefully to make sure no mistakes were made by yourself or the game's track engraving logic.

'''Constructed'''

Tracks can also be built as regular [[construction]]s (through {{K|b}} {{K|C}} {{K|T}}). This method is resource-expensive, since each track tile requires one stone, [[bar]], or [[block]] for construction, and time-consuming, since you can't designate strips longer than 10 tiles at a time. Corners, crossings, T-junctions, and ramps also have to be designated individually. However, it is usually the only way to build tracks above ground or on soil (barring the [[Obsidian farming|creation of obsidian]]). Constructed tracks are designated for removal like any regular construction; be aware that removing track ramps built on top of natural ones will also remove the original ramp, leaving a flat floor.

====Ramps====

'''Carved'''

The carving of natural ramps is a little more confusing: to carve a two-way track on a ramp (natural only, does not work on constructed ramps), you must designate the track '''starting on the ramp and one square beyond''' in the direction you want the track to go. For the side of the ramp square you want to head upward, there '''must''' be either a natural or constructed wall in the square next to it, otherwise the game assumes you are trying to carve it on the same level -- this can result in the track being carved underneath a door or other object. If you have accidentally done this, you can correct it by smoothing the ramp and constructing a single square of wall next to it, then re-carving the ramp correctly. (However, the wall must stay there permanently; removing it will disconnect the track.)

'''Constructed'''

When constructing track ramps, the stated direction should be the same as the connected tracks. For example, a track going up from West to East would require, starting from the West, a Track (EW), a Track/Ramp (EW) and a Wall behind the ramp, underneath the section of track above it. Incorrectly placed ramps result in minecarts ignoring the ramp and crashing into the supporting wall. They will not, however, display as unusable as when the supporting wall is missing.

'''Examples of ramps'''

A simple ramp would look like this:
{{diagram|spaces=yes|\
z +0 z +1
░░░░ ░░░░
═▲o ░▼═
░░░░ ░░░░
o : wall
}}

Carving track corners into ramps is rather unintuitive and complicated. Since engraving tracks always requires two tiles to connect in a straight line as input, you have to give two separate designations for a single job: a track bit from the ramp tile to the "below" direction and another one to the wall of the "upward" direction. If you wanted to change direction on a ramp from east to north:
{{diagram|spaces=yes|\
z +0 z +1
░░░░░ ░░░░░
░░░░░ ══╗░░
=▲░░ ░░▼░░
░░░░░ ░░░░░
}}
you would need to connect the ramp on z +0 both to the west and to the north by issuing two "carve track" commands, one selecting the ramp and the track tile to the west, and another connecting the ramp tile with the wall to the north. An engraver would then carve a NW track corner into the ramp, allowing carts to pass the corner correctly both going up and down. Such track corners are perfectly serviceable for guided carts, but moving down a route of several of them by pushed or ridden cart is problematic - ramps on corners behave very counter-intuitively, resulting in loss of speed when going down and diagonal movement when going up.

Moving to and from ramps (or between ramps "pointing" in different directions0 causes some non-trivial adjustments to speed and even moving along the tiles at a fixed speed ''unrelated to the entry/exit velocity values'', because transitions to/from ramps are processed differently and are not to be "skipped". This affects compact track/ramp combinations (such as e.g. a simple 2x2 ramp spiral) most, and combined with bouncing often makes them work not in the way one could expect. {{cite forum|144328/5705102}}

{{anchor|Tracks}}

=== Hauling route ===
A hauling route is a list of directions describing how and under what conditions a minecart will move. The proper setting up of routes is essential for a working rail system. Routes, stops, departure conditions and stockpile links are managed from the {{k|h}}auling menu.

==== Route ====
A route defines the path a minecart will take along a track, as well as under what conditions it will move or stop moving. A route is made up of stops. Stops are precisely what they sound like, a position on the track at which you want a minecart to stop. A minecart track might use as little as a single stop for a looped track, which will serve as both a starting and stopping point for the cart, or it could contain many stops, perhaps to load supplies or wait for a bridge to be manually lowered, before reaching its destination or returning to its starting point. It is important to note that you only need to place stops on a route where you actually want the cart to stop and wait for some action to occur. They are not needed to help navigate the cart along the track beyond telling it where on the track to stop.

New routes are created with the {{k|h}}auling key. Existing ones can be removed (without confirmation) with the {{k|x}} key, and also {{k|n}}icknamed. Before operating, the route must have a {{k|v}}ehicle assigned to it (this can be done with either the route or a stop selected). Assigning a full minecart to a route may result in a slow hauling job if the contents are heavy.

==== Stops ====
Stops are the individual waypoints that make up a hauling route. A given stop consists of the location of a tile, as well as conditions describing when, where, and how a cart should be moved after being stopped at that tile. Stops can be created from within the {{k|h}}auling menu, by placing the cursor over a tile and hitting {{k|s}} while highlighting the route (or a stop within) you've already designated. A minecart will begin its route at the first stop created, and continue through each subsequent stop, being guided, pushed, or ridden from each stop to the next depending on the conditions specified. In many basic minecart applications, the cart will end up at the same stop it began at, though this is not always the case. It is important to note that hauling stop order is enforced, even if there is no track. A dwarf will drag the cart overland back to a skipped stop in the route's list if your tracks bypass it somehow.

Once a stop has been placed, it is given a default set of conditions under which to move the minecart if it is stopped there. Each new stop gets the same default conditions regardless of the track it is placed upon (e.g. guide the cart to the north). For this reason new stops might get marked by yellow exclamation marks ({{DFtext|!|#ff0}}) due to invalid directions. One important thing to note is that as you place additional stops, the display will show paths between the stops you have defined. However, this is '''not''' necessarily the actual route the minecart will take once the route is in operation. For example, if a route were defined with two stops at opposite ends of a track with many twists and turns, a line will be drawn directly between those stops to show the order in which they will be visited. These route lines may crisscross all over the tracks, but so long as the track is valid end to end, the cart will follow the track from one stop to the next, even across twists, turns, and z-level changes. Stops, which are the steps that make up a route, should not be confused with Track Stops, described below.

===== Stockpile links =====
By placing the cursor on top of a stockpile and using {{k|s}}, you can create stockpile links while defining a hauling stop. Links can also be redefined by selecting them, placing the cursor over a different stockpile, and pressing {{k|p}}. The cart will then be filled by items present in its various linked stockpiles in preference to other items. Note that bins should be used with caution in stockpiles that are linked to minecarts. Bins cause problems when used with the "Desired Items" list in a stop's conditions. For example, if a minecart is set to accept only granite blocks, and to depart north when it is 100% full of granite blocks, it will not depart if any of those granite blocks are in bins, even if bins are also included in the desired items list. Two solutions to this problem exist as of v0.40.24. First, bins can be disallowed in stockpiles that are linked to stops. Alternatively, bins '''can''' be used in conjunction with minecarts provided that the minecart's departure conditions use only "any items" instead of "desired items." This option can be toggled in the advanced conditions menu for a stop, accessible via the {{key|C|}} key. The cart's contents can still be controlled by specifying what items are allowed in the linked stockpile.

===== Departure condition =====
Departure conditions involve setting conditions in which the minecart will leave on the route. Each condition includes:
# A departure mode (Guide, Ride or Push).
# An initial departure direction (NSEW). Note that this defines the initial direction of movement only. Even if a track includes many turns, as long as the initial movement direction is valid the cart will follow the minecart track thereafter.
# A timer, before which the departure condition cannot be met.
# Conditions on the amount of items in the cart.
Departure conditions are created with the {{k|n}} key. A new departure condition will read: "guide north immediately when empty of desired items". This condition can be changed between basic presets with {{k|c}}. "Advanced" mode ({{k|C}}) allows for more precise control over departure conditions: fine tuning the percentage from 0 to 100 in 25% steps ({{k|f}} and {{k|F}}), switching it being either the maximum or the minimum amount of items for the condition to be met ({{k|m}}), and whether the cart accepts all or only a specific set of items ({{k|l}}). Common to both screens are the departure mode ({{k|p}}, Push, Ride or Guide), {{k|d}}irection, and timer ({{k|t}} and {{k|T}}) options.

To have a cart only carry a specific set of items, the stop can be set to only carry "desired" items, opening the selection screen with the {{k|Enter}} key while having said stop condition selected, and toggling as desired, or it can simply be linked to a stockpile and set to depart once it is full of items from its linked stockpiles, regardless of type.

=== Track Stops ===
A Track Stop, not to be confused with a route stop, is an optional, single-tile construction which serves two purposes. First, it can be used to cancel a cart's momentum in order to slow or stop it as it passes over the Track Stop. This might be necessary if a cart were pushed down a series of ramps to its destination. Second, a Track Stop can cause a cart to automatically dump its contents as it passes over the Track Stop. Track Stops are constructed via {{k|b}} {{k|C}} {{k|S}}, and must be constructed atop an existing piece of track. If a Track Stop has been set to automatically dump a cart's contents, the cart will dump its contents in the direction indicated when it passes over the Track Stop. Depending on the friction settings chosen for the Track Stop, the cart might then stop after dumping, or it might continue on its route to another destination.

Track Stops are not mandatory; in fact, their main use is in automated rail systems. However, even in basic rail systems it can be useful to set a Track Stop to dump items: this saves time that dwarves would otherwise spend in removing items from the cart, time that is better spent driving the cart back to where it's needed. Dumping will occur even with a guided cart. '''Take care not to set Track Stops at a loading site to dump their contents''', or dwarves will never be able to fill the cart. It will dump any contents the moment they are loaded.

Counter-intuitive to their construction method, Track Stops are considered [[building]]s and must be removed by {{k|q}} {{k|x}}.
* See [[#More_on_Track_stop |More on Track Stops]]

=== Step-by-step tutorial ===

Let's construct a simple minecart route. This route will move stone blocks from an input stockpile to an output stockpile. We'll begin by creating the stockpiles:

[[File:minecart-example-1.png|Stockpiles designated.]]

The input stockpile is on the left; the output stockpile is on the right. We'll be moving blocks from left to right. Disable bins in both stockpiles, and set the input stockpile to accept only from links. Then make the stockpile take from the mason's workshop where the blocks are being produced.

Next, carve the track:

[[File:minecart-example-2.png|Track carving designation.]]

Note that the ends of the designation are uniquely shaped; this is automatic, and not anything you need to control. Now, wait for your engravers to come along and carve the track into the stone. (Your haulers will probably also fill up the input stockpile while you wait.)

In addition, while we're waiting for that to happen, we'll build an iron minecart in the forge.

[[File:minecart-example-3.png|Track carved.]]

When the track has been carved, it will look like the above (the track will be solid instead of flashing). Now, order a track stop to be constructed next to the output stockpile:

{|
| [[File:minecart-example-4.png|Track stop designation.]]
| [[File:minecart-example-5.png|Select dumping direction.]]
|}

You must press {{k|d}} three times to select the dumping direction ''before'' placing the track stop. We want our blocks to be dumped into the output stockpile east of the track stop. Then wait for a mechanic to come along and build the track stop.

[[File:minecart-example-6.png|Track stop constructed.]]

Now we'll define the actual ''route''. This is done in the {{k|h}}auling menu. Press {{k|r}} to begin defining a route. Next, move the cursor to the input end of the track, and then press {{k|s}} to define the first stop:

{|
| [[File:minecart-example-7.png|Stop 1 designation.]]
| [[File:minecart-example-8.png|Route definition, in progress.]]
|}

Move the cursor again, to the output end of the track, and press {{k|s}} again to define the second stop:

{|
| [[File:minecart-example-9.png|Stop 2 designation.]]
| [[File:minecart-example-10.png|Route definition, two stops.]]
|-
|
| [[File:minecart-example-11.png|Stops are not defined yet.]]
|}

There are several user interface features to note at this point. The stops have been positioned, but they haven't been ''defined'' yet, so there is a warning {{DFtext|!|#ff0}} symbol by each of them. In the lower right corner, we see what the {{DFtext|!|#ff0}} means. Also, note that the second stop is labeled in white, while the other two lines are grey. The white text is a selection indicator, and can be moved up and down by pressing {{k|+}}/{{k|-}}.

Next we need to define what our stops do. We want the minecart to be filled with blocks at the first stop, then travel to the second stop where it will dump its cargo, and then return. Press {{k|-}} to move the selection up to stop 1, and {{k|Enter}} to open it up. By default, the stop has three conditions:

[[File:minecart-example-12.png|Default stop definition.]]

We don't want any of these, so press {{k|x}} three times to delete them. This leaves us with a blank stop. Now we can add the conditions we actually want. Press {{k|n}} to begin adding the first condition, then {{k|d}} twice to change the direction from north to east. Then press {{k|c}} to change the condition from empty to full. This will instruct the minecart to be guided east when full of desired items.

To set the desired items, we create a stockpile link. Press {{k|s}}, then move the cursor to the input stockpile, then press {{k|p}} to select that stockpile. Now press {{k|Enter}}; this opens up a selection screen that resembles the stockpile customization screen. Move down to Blocks, {{k|e}}nable them, then (if you wish) restrict it to stone blocks.

When you've done all that, stop 1 should look like this:

[[File:minecart-example-13.png|Stop 1, defined.]]

Stop 2 is much simpler. All we need to do is have the minecart return to the input stop. So, make a condition and change the direction:

[[File:minecart-example-14.png|Stop 2, defined.]]

Finally, we just have to assign our minecart. Go back to the route definition screen, and press {{k|v}}. Select the minecart, and press {{k|Enter}}.

Now we've got everything set up:

[[File:minecart-example-15.png|Route, fully defined.]]

The V is red because the minecart hasn't been moved onto the track yet. Some dwarf will have to haul it from the forge to the first stop, by hand; this will take a while, especially if the forge is far away.

Once the minecart is in place, dwarves should fill it with blocks from the input stockpile, which will in turn be filled with blocks from the workshop where your mason has been toiling dutifully. When the minecart is full, the blocks will be dumped into the 1x1 stockpile on the right. Automatic quantum dumping!

=== Troubleshooting ===

Because of the complexity of the system, all but the most careful and experienced minecart users will encounter issues. Most route issues can be diagnosed and fixed from the {{k|h}}auling menu.

'''Symptom:''' {{DFtext|! Set dir/connect track|6:1}} message appears to the right of one or more stops

'''Possible Causes:'''
* The departure direction of the stop might be invalid. Edit the stop using {{k|Enter}} and press{{k|d}} until it is pointing in a valid direction.
* The track stop might not be built on top of a track. The track stop must be deconstructed to remedy this issue.
* Your track might not be built correctly. Make sure all connected tracks between destinations are not one-way tracks.
** This can be especially confusing with ramps. To carve a two-way track on a (natural) ramp, you must designate the ramp and one square beyond in the direction you want the track to go.
** Ramps '''must''' have a solid block on the side opposite to the track, or they will neither work nor be marked as "unusable". The solid block can be natural or constructed.
* The desired/kept items might not be configured correctly.

'''Symptom:''' The status '''0% V''' always appears to the right of one stop.

'''Possible Causes:'''
* The stop may not be set to take from a stockpile. Edit the Stop using {{k|Enter}} and make sure you see a message like "Take from Stockpile #1".
* The take conditions must correspond with the contents of the stockpile.
* The track stop may be set to dump. A track stop set to dump cannot be filled. You must either set the stop to a time-based departure or deconstruct the track stop and rebuild it without dumping. (Alternatively, with [[DFHack]] you can modify "Dump on arrival" to "No" using the {{key|q}} menu without rebuilding the stop.)
* Make sure the minecart itself has not been designated to be dumped (such as when using mass-dump).

'''Symptom:''' Dwarves fill the minecart properly, but will not move it thereafter.

'''Possible Causes:'''
* The minecart may contain items which are not included in its current stop's desired items. Check inside the minecart using the {{key|k}} and {{key|z}} keys and ensure that all items in the cart are desired items.
* The minecart may contain desired items in bins. Minecarts seem to have problems realizing that they are in fact full of desired items if some of those items are in bins, even if bins are also among the desired items for that stop. '''This cannot be solved by adding the appropriate bins to the stop's desired items.''' Either disallow bins in stockpiles you intend to load minecarts from, or set the departure conditions to rely only on percentage of total load rather than percentage of desired items using the advanced conditions menu ({{key|C}} key).

'''Symptom:''' Dwarves repeatedly attempt to load the minecart, but no items are ever loaded into it.

'''Possible Causes:'''
* This can be caused by using a Track Stop with autodumping enabled at a loading site. Every time a dwarf places an item into a cart resting on such a track stop, the item will be immediately dumped, causing unlimited, useless cart loading jobs. Autodumping Track Stops should never be used at a loading site.

'''Symptom:''' A dwarf picks up the minecart and carries it to its destination.
* See [[#Quirks|Quirks]]

=== Danger ===
Minecarts are not without <strike>danger</strike> [[fun]]. Although designating a track automatically sets the [[traffic]] designation to low, dwarves ''may'' still walk on them, and [[creature]]s ignore traffic designations altogether. If an unlucky dwarf or creature fails to [[dodger|dodge]] a minecart, they can be injured. Most of this danger can be avoided by setting the minecart {{k|h}}auling commands to guide instead of push or ride (dwarves guiding minecarts will ignore traffic restrictions), as well as by [[pasture|pasturing]] domestic animals and preventing the access of other creatures to the tracks. Note that removing the track doesn't reset that tile back to normal traffic priority, so you may wish to manually clean up traffic designation afterward. Also note that bridges that are used as tracks don't have their traffic priority changed automatically (since they're just normal bridges), which could cause dwarves to pathfind normally through dangerous minecart entrances in your fort's walls if you're not careful.

The only <s>fool</s>''dwarf''-proof method is to make the tracks inaccessible. There are several ways to create a track which works for minecarts but doesn't allow creature-traversal; the simplest is perhaps building a [[statue]] on the tracks. Other options include adding single-tile holes (minecarts moving at reasonable speed will jump the gap), vertical drops, minecart-triggered doors, small pools of liquid (4/7 water or 2/7 magma), and hostile creatures overlooking the tracks. For safety, both ends of the track should be isolated, making the dangerous center sections completely inaccessible (though maintenance access can be provided by a locked door).

Danger does not always involve living victims: careless route designation can also result in minecarts careening off tracks or colliding with each other. If this occurs, the [[item]]s may be scattered; this can cause even more hauling jobs than the minecart aimed to eliminate. Even <s>better</s> worse, scattered items, especially [[weapon]]s, can injure passing [[dwarf|dwarves]] or other [[creature]]s; in the words of Toady One the Great, "Accidental grapeshotting of the dining room should be possible now."

Of course, the danger of using minecarts means they can also be [[Trap_design#Minecarts|used as weapons]] by imaginative players.

== Advanced usage and automation ==
Minecart-specific effects are implemented via track stops, rollers and [[pressure plate]]s with "track" condition set. Since all three are considered [[building]]s, they can't be built on the same square (however convenient track stop + pressure plate would be) nor a simple ramp, and are removed by {{k|q}} {{k|x}}.

=== More on Track stop ===
Track stops are constructions that allow further automation of minecart systems via adjustable features such as braking by friction and automatic dumping of contents. They can be built from logs, bars and blocks through {{K|b}} {{K|C}} {{K|S}}; friction amount, dumping toggle and dumping direction must be set '''before''' construction, and these settings can be neither changed nor seen thereafter; however, track stops can be linked to [[pressure plate]]s or [[lever]]s to toggle friction and dumping On or Off (trigger state is inverted: switch On = track stop Off).

If a [[stockpile]] is placed on the tile that a track stop is set to dump to, it can act as a [[Exploit#Quantum_stockpiles|quantum stockpile]] and any items dumped from a minecart that match the storage settings of the stockpile will remain there and accumulate. Normally trackstops are built on top of existing track to operate on moving minecarts, but they can also be used without tracks to create [[Exploit#The_Minecart_Stop|automatic quantum stockpiles]] (see also [[#Step-by-step_tutorial|step-by-step tutorial]]). It is not always desirable to collect ALL of certain items into one quantum stockpile, such as when distributing a material to multiple separate industries. You can link your quantum stockpile to various other stockpiles, ensuring that your dwarves will keep them supplied as necessary. Because quantum stockpiles never fill up like regular stockpiles, it may be a good idea to add a switch to turn them off.

Items dumped from a minecart at a track stop (or dumped by any other means) into open space fall through z-levels until they land on a solid surface. Items falling onto a designated [[stockpile]] will automatically be considered part of that stockpile, even if the stockpile is set to disallow those items (they will, however, be automatically moved to a more appropriate stockpile, if available). Items falling on top of a minecart will '''not''' fall "inside" the minecart. Use with caution; dwarves have fragile skulls.{{bug|5945}}

=== Automated propulsion ===
==== Roller ====
{{Main|Roller}}

A '''roller''' is a [[power]]ed [[machine component]] for the automated propulsion of minecarts. They are built over the top of existing tracks with {{K|b|M|r}}, requiring a [[mechanic]], ''(length/4)+1'' [[mechanism]]s and a [[rope]]. Rollers may also be placed directly on ramps to help pull carts up Z levels. Rollers are very useful to maintain a cart's momentum along long routes, to get them to climb Z-levels without dwarfpower involved, and to get them to reach speeds unattainable by guiding dwarves. These devices are variable-length (1-10), variable-direction and variable-speed ([[Minecart#Numbers_behind_the_scene|see below]]), all traits that can be set at construction time; a roller uses two units of power per tile it is long.

Single-tile rollers transfer power in all four cardinal directions, while other rollers generally only transfer power perpendicular to their activity direction. Longer rollers can also transfer power along their activity direction if built in the correct order, although this can be hard to accomplish and is easily broken. Rollers cannot be powered from above.

Rollers have great acceleration and capped speed. Carts going faster than the roller are unaffected. If a cart moves across an active roller in the direction the roller works and moves slower than the roller's specified speed, the cart will be set to the roller's speed. A cart going against a roller's movement direction will be sent back the way it came (once again at the roller's speed), unless it was moving extremely fast: speed increment of 100000 allows to reverse carts from the full "highest" (50000) speed roller to full "highest" speed back, but ramps can accelerate a cart beyond this. {{cite forum|144328/5702453}}
A cart crossing over a roller perpendicular to its current movement direction will gain the roller's amount of speed in the perpendicular direction without directly changing its forward motion. Without an adjacent wall to constrict its movement, this will typically send a cart off the rails on a diagonal path, completely unable to follow any tracks until it collides with a wall or is otherwise brought to rest. However, if the roller is placed over a track turn and pushes ''from'' the direction of that turn's track, the turn affects carts ''after'' the roller, so they will be forced into the turn rather than derailed in a diagonal direction. {{cite forum|144328/5702453}}

{{diagram|spaces=yes|\
tracks: full:
║ ║
═╗═ ═╢═
║ ║

╢ : roller pushing from W to E
}}
If the roller is powered, carts from ''all'' directions (unless too fast) exit S, because speed imparted by the roller forces carts toward E and ''then'' into the turn.
If not powered, carts from W and N exit S, carts from E and S exit W. Carts above derail speed will ignore the turn, of course.

{{diagram|spaces=yes|\
║ ║
═╗═ ═╟═
║ ║

╟ : Roller pushing from E to W
}}
Carts from the E or W: exit W.
Carts from N: derailed diagonally, exit SW.
Carts from S: derailed diagonally, exit NW.

Rollers affects carts on a track - if placed on a floor or ramp without any tracks, they are ignored. Depowered rollers are also ignored, friction is determined by the tiles underneath.

Because of their one-way nature, rollers are unsuitable for most two-way minecart tracks (unless you set gears toggling roller A->B off while toggling A<-B rollers on). However, a minecart set to be ''guided'' is not affected by rollers at all{{cite forum|109460/3286235}} — this allows a one-way track to be used in both directions. In addition, unpowered rollers do not affect minecarts.

Care must be taken in [[glacier]]s and other extremely cold [[biome]]s, since rollers (and the machinery used to power them) will not operate when constructed on natural [[ice]] floors.

==== Impulse ramps ====
Carts can be given momentum without rollers or changing z-level through a phenomenon called "impulse ramps". A track ramp which is connected both to a wall and to a floor will ''always'' accelerate a cart towards the connected floor tile, no matter where the cart enters the tile from. This means carts can be accelerated as though dropping z-levels, even if the cart doesn't actually change z-level at all. If a track ramp faces three directions such as ╩, then two of those directions need to be facing walls for the cart to be accelerated towards the remaining direction.

Example of straight impulse acceleration:

{{diagram|spaces=yes|\
▒▒▒▒▒▒▒▒▒▒ ▒▒▒▒▒▒▒▒▒▒
═▲▲▲▲▲▲▲▲▲▲═ ═╚╚╚╚╚╚╚╚╚╚═
▒ : Wall
═ : Normal track
▲/╚ : N/E Track/Ramp
}}

If a cart enters from the left, it will speed up on every track/ramp and exit to the right going very very fast - more than one tile every step. If it enters from the right then it will bounce back impulsed by the ramp if it's going slow enough.

As another oddity, carts coming from ramps will in some cases "teleport" through most of the next tile. This can be used to send carts up levels with minimal loss of speed. You can just make an upward spiral alternating impulse ramps and regular upward ramps. It takes no power, is quick and cheap to build, requiring only channeling and track carving, and the cart goes up fast, but not so fast that it launches its contents.

Example of an impulse elevator:

{{diagram|spaces=yes|\
z +0 z +1 z +2 z +3
░░░░░ ░░░░░ ░░░░░ ░░░░░
░╔░░░ ░▼╚╗░ ░░▼▼░ ░░░░░
░╝░░░ ░▼░░░ ░░░╔░ ░░░▼░
░▼▼░░ ░░░░░ ░░░╝░ ░╚╗▼░
░░░░░ ░░░░░ ░░░░░ ░░░░░

░ : Wall
╔,╚,╗,╝ : Track/Ramp
▼ : Down Ramp (empty space)
}}

Note that this impulse elevator, due to the checkpoint effect and upward ramp curve effect, will not actually result in carts traveling straight up the ramp. They will lose speed, bounce off a ramp, then be accelerated back into the spiral after a 9-turn delay on both tiles on the floor where they are stopped. This is because the checkpoint effect allows carts to travel up the ramps in a single turn, but also prevents the impulse ramps from adding acceleration unless the cart is slowed to staying on the ramp for more than one turn. Initial acceleration will carry the cart up a variable number of floors before this effect occurs, but this bouncing back and forth will occur every 5 z-levels after the first time the cart stops. When the cart ''is'' traveling upwards, it will pass every tile at a rate of one tile per turn regardless of its actual speed, due to the checkpoint effect. In tracks with only a single cart, this is negligible, but when multiple carts are on the same track (such as when you place multiple carts on a magma cart lift) this can cause collisions which derail carts or cause other unexpected or undesired behaviors.

The following impulse ramp (while larger) should alleviate these problems with additional impulse ramps that actually have enough time (more than one turn) to add speed (although a derail checkpoint may be required to prevent excessive speeds):

{{diagram|spaces=yes|\
z +0 z +1 z +2 z +3
░░░░░░ ░░░░░░ ░░░░░░ ░░░░░░
░░░░░░ ░╔╔═░░ ░▼▼▼╗░ ░░░░▼░
░║░░░░ ░▼░░░░ ░░░░╗░ ░░░░▼░
░╚░░░░ ░▼░░░░ ░░░░║░ ░░░░▼░
░╚▼▼▼░ ░▼░░░░ ░░░░░░ ░░═╝╝░
░░░░░░ ░░░░░░ ░░░░░░ ░░░░░░

░ : Wall
║,═,╔,╚,╗,╝ : Track/Ramp
▼ : Down Ramp (empty space)
}}

Also, if you want to have a cart following a regular speed, the following track works well:
{{diagram|spaces=yes|\
z +0 z +1 z +2 z +3
░░░░░ ░░░░░ ░░░░░ ░░░░░
░░░░░ ░══░░ ░▼▼║░ ░░░▼░
░║░░░ ░▼░░░ ░░░║░ ░░░▼░
░║▼▼░ ░▼░░░ ░░░░░ ░░══░
░░░░░ ░░░░░ ░░░░░ ░░░░░

░ : Wall
║,═ : Track/Ramp
▼ : Down Ramp (empty space)
}}
In this elevator, the cart collides with the walls in the corners, but then realigns on the ramp, picks up speed, checkpoints through the next ramp, and slams into the next wall. It is slower (10 ticks per floor) but produces reliable speeds, and will exit the impulse elevator at little more than push speeds.

A sort of opposite effect to impulse ramps also exists: ramps lacking the proper "up" and "down" connections are treated as flat track, even if they actually go up or down z-levels. This allows building "anti-impulse" slopes consisting entirely of ramps only connected up, which a minecart can travel up forty levels and more, needing no more than a single push.

=== Controlling traffic ===

==== Switching ====

As constructions or tile features, [[door]]s and other furniture can be built on tracks. A [[door]] or [[floodgate]] can be turned on or off by a [[lever]], effectively controlling the flow of automated minecarts. This may be <s>dangerous</s> [[fun]], however.
{{diagram|spaces=yes|\
->
A ════┤≡════ B
┤ : roller pushing to East
≡ : door
}}
The roller pushes the cart east, but until the "departure condition" is fulfilled, the door remains closed and blocks the path.

[[Bridge]]s can also act as tracks, but only if they're lowered or not retracted. This property can enable levers to turn tracks on and off. However, care should be taken to ensure that such bridges are never operated while a cart is on top of them, as the cart will be flung off the track. It's worth noting that it's often faster, and cheaper, to construct large bridges than long sections of constructed track.

A powered track switch can be constructed by building an "inverted" corner as illustrated below.
{{diagram|spaces=yes|\
B B
║ -> ║
║ ║
════╚═══ ════├════
A C A C
├ : roller pushing to West.
}}

If the cart is pushed East from the stop at 'A' while the roller is activated, it will arrive at 'B'. If the roller is not running, it will arrive at 'C'. The switch works by the roller first reversing the incoming cart's movement and the cart ''then'' following the track corner.

This switch is very reliable, reacts instantly to on/off signals, and carts of any speed can be switched by this design, although very fast carts will require rollers that are several tiles long, up to three. The requirement for power can be inconvenient or impractical. Non-powered solutions may use controlled derailment, or a connecting bridge.
{{diagram|spaces=yes|\
B ╥
║
║
╞════╝ ════╡
A D C
}}
Here the track between A and C is not continuous. The only continuous track is A->B, with a corner (not a T section). Fast moving carts will tend to derail at D and rejoin the track to C. Placing a door at D will prevent the derailment, so the cart continues to B. The door is operated by mechanisms elsewhere (typically, a lever, but some fun can be had with pressure plates).

Since it depends on derailing, this switch requires a very fast cart, faster than what can be achieved with rollers alone. To gain sufficient speed, a cart must be accelerated further, usually by descending several levels or through impulse ramps. The high speed makes the cart much more dangerous and harder to control.

If carts are moving too slowly to derail at the corner, a retractable bridge may be used as a connector between A and C.
{{diagram|spaces=yes|\
B╥
║
║
A╞════bbb════╡C
}}
The bridge must overlap the corner. Bridges behave like a track crossing, allowing carts to pass in a straight line. When retracted, the corner reappears, so the carts will continue to B. Bridges take 100 steps to react to a signal, necessitating rather long "lead times" when switching tracks via bridge.

As mentioned above, special care must be taken to make sure the bridge doesn't change state while the cart is passing over it. Retracting bridges will throw the cart, causing it to stop dead. Raising bridges can even crush the cart.

==== Controlling Speed ====


Minecarts can reach extremely high speeds, especially when descending multiple Z-levels. A minecart will derail at a track corner if its speed exceeds 0.5 t/st (tiles per step), '''unless''' the route in the direction of travel is blocked:

Will derail at > 0.5 t/st:

{{diagram|spaces=yes|\
in ══╗ -> derailing
║
out
}}

Will not derail at > 0.5 t/st:
{{diagram|spaces=yes|\
in ══╗O
║
out

O : wall/column.
}}

This behavior can be used to build a "speed limiter", that will ensure that when a minecart exits it is traveling below derail speed:
{{diagram|spaces=yes|\
░░░░ ░░░░░ ░░░░░
in ═╔═╗░ ░╔S╗░ ░╔S╗░
out ═╬═╝░ out ═╗═╝░ out ═╗═╝░
░╚S╝░ ░╚═╝═ in ░╚S╝░
░░░░░ ░░░░ ║░░░
in
░ : wall
S : Track Stop (High Friction or lower)
}}
If the minecart is traveling below derailment speed, it will not be affected; if above, will be slowed down and checked again. Granted, you could do the same just with track turns, but it may take a lot of turns and time.

Since all the derailings, bounces and ramps can impart a sideway component of speed small enough to start visible drift many tiles away (say, [[Fun|in the middle of a bridge]]), track turns have one more use: forcing the carts to move strictly along the grid directions. Carts passing a turn below derailing speed convert one component of velocity into another, thus eliminating the drift.

=== Loading liquids ===
[[Water]] and [[magma]] can also be loaded into minecarts by submerging them to a depth of at least 6/7 while standing still or moving at speeds of at most 10000. Loading fluids onto minecarts can be difficult because the added friction provided by fluids can stop a cart in a submerged tile. Curiously, filling a minecart with magma does not injure a dwarf ''riding'' it. A minecart will hold enough fluid to increase the depth of a single tile by 2. This amount is listed as 833 units, which weigh 459Γ (water) or 999Γ (magma). An iron or steel cart filled with magma weighs 1313Γ, while an adamantine cart filled with magma weighs 1007Γ. Since you need a minecart above the liquid's level, possible arrangements may include pressure-activated sluices, rollers (with magma-safe chains for magma), pouring from above to "submerge" it briefly on the same level and drain excess away (dig deeper and leave a vaporizer, though if you could have power for rollers, may as well use a pump) and exploits with ramps (not necessarily impulse ramps, "same height" passing dip does it).
The liquids can be dumped by a constructed track stop.

== Quirks ==
This little quirk concerns dwarf-managed minecarts. If a track which was previously open becomes blocked (ex. flipping a switch connected to a floodgate you've built on the track to raise it) and the conditions for departure are met, instead of refusing to ride/guide the minecart or ride/guide it until it reaches the obstacle, the dwarf will pick up the minecart off the tracks and haul it to its scheduled destination on foot. If the distance is long enough and the weight of the cart heavy enough (due to being filled with heavy items such as stones), the dwarf may drop the cart because of fatigue/hunger/thirst before reaching the destination. This will cancel that vehicle setting job and make another dwarf come by and attempt to haul the cart to the nearest appropriate stockpile where another dwarf will pick up the cart and attempt to haul it to its initial stop. If the stockpile is far enough from initial stop, this second dwarf who is attempting to place the minecart on its tracks may also drop the minecart out of fatigue/hunger/thirst creating a loop that will go on until a dwarf with enough endurance manages to place the minecart where it belongs.

In fact, it seems dwarves are more than happy to attempt to carry a minecart from one stop to another even if just waiting until the track is open again would be the more sane option.

Dwarves will also carry a minecart to its next stop if the direction specified is incorrect (or invalid). This can often occur when using the default departure settings and forgetting to set the direction of each condition.

Dwarves can admire buildings while riding mine carts. Dwarves will not fall asleep during a ride (at least not from being drowsy). If riding on a continuous powered track loop, the dwarf will die of dehydration/starvation as they can not jump off to get sustenance{{cite forum|109460/3377228}}. Dwarves riding in submerged minecarts will gain experience in [[swimming]].{{cite forum|129889}}

Tracks block wagon access to trade depots, unless they're on a ramp. [[Bridge]]s can also be used, as they function as tracks but do not block wagons.

== Physics ==


Minecart physics depend greatly on the departure mode set in the route stop conditions.

When set to "Push" or "Ride", minecarts will move according to the regular laws of momentum, gaining speed when going downhill, losing it slowly due to friction when on a flat plane, and more quickly when going uphill. In these modes, minecarts will move in a straight line until they either are brought to a stop by friction or an obstacle, or until they encounter a turn. A minecart will roll straight past "blocked" ends of T-junctions or track ends, they have no power to restrict a cart's movement. The cart's behavior is largely independent of the weight of its contents (including fluids and dwarves): heavily loaded carts gain more momentum when accelerating, but this only plays a role in collisions: a heavy cart gains just as much speed and is as easy to stop as a light one. In either case, dwarves can not push nor ride an unpowered cart up a ramp, bouncing back the direction it came. At best, this is a waste of time; at worst, it will give your cart-pushing dwarf a [[fun|fun surprise]]. To solve this, the player can either use Rollers (see below) or set the cart to be Guided.

The difference between "Push" and "Ride" is whether the dwarf will go along with the cart or not.
{{DFtext|Push}}: the dwarf will give the cart an initial push, not enough to go up a ramp, but enough to go some way along flat track, and the dwarf will remain at the first stop, ready for a new job.
{{DFtext|Ride}}: the dwarf will give the cart the same initial push and then hop aboard the cart riding with it to the next stop.
{{DFtext|Guide}}: minecarts seem to ignore all laws of physics. That is:
*Ignore the weight of any and all items inside. Therefore:
**Move at the speed of the dwarf that is guiding them. It is thus recommended to pick the most [[attribute#Agility|agile]] of your dwarves for cart-guiding tasks.
*Ignore working rollers.
*Will ''not'' collide with other guided carts even when a full frontal collision would be expected.
*Will go up ramps like nobody's business.
This is therefore the recommended method of transport for simple non-powered rail systems, despite it diverting a dwarf from other, potentially more important tasks.

Some samples with behavior:
{{diagram|spaces=yes|\
A <-> B A <-> C A <-> B
B B B
║ ║ ║
A══╝ A══╩══C A══╬╗
You can only go A->B ╚╝
Works when the cart Works
is in Guide mode.
}}
In the second example above, a cart "pushed" from B will go over the junction and roll off into the unknown south.

=== Track Direction Irrelevance ===
Carts that are traveling independently, (that is, not guided,) only care that tracks ''are'' on the tile, not which direction the tracks actually move. Tracks respect only curves (with two exits) and ramps.

This means, for example, that the following tracks, when a (non-guided) cart travels from West-to-East, are functionally identical in effect:

A════════════B A╬║╚╔╣╩╦╠╥╨╞╡B

This is because so far as the cart is concerned, only ramps and curves with two exits where the exit in the path they are traveling matters.

Carts only check for curves when they are halfway through a tile. When they get there, they look to see if their path has no exit. (That is, if it is traveling East, it checks if there is an East exit.) If there is, it ignores all other track directions, and keeps traveling. If there is not, it checks to see if there are only two exits to the track, and if one of those directions was the direction it "came from". (That is, if traveling from the East, it checks if there is a valid exit to the West, and if so, if there is either a North exit or a South exit.) If there is not, it ignores the track anyway, and keeps on traveling as though it were still on track. If there is, it will subtract 1000 from the velocity of the cart, and redirect all forward velocity to the direction of the curve. This change in the direction of velocity ''overwrites'' any "diagonal" velocity, which can prevent diagonal velocity derailments, but any perpendicular velocity is not preserved, and is instead discarded.

=== Invalid Ramps ===
Ramps are functionally defined for cart purposes as being a tile which exerts an acceleration force upon its "downward slope". This downward slope requires a cart to have one ''and exactly one'' carved exit to the tile that is the "bottom" of the ramp. Ramps push carts in this "downward" direction (possibly leading to diagonal movement, below), and the deceleration of an "uphill" ramp is actually just the acceleration being applied against the direction of a cart's movement.

This is where players can find an exploit in the behavior of ramps - if there are ''two'' "downhill" exits to a ramp (such as a "T junction" on a ramp where only one exit faces a wall), then the ramp provides no acceleration ''or'' deceleration, allowing carts to travel up ramps without any loss of momentum except for the standard "flat track" deceleration, because as far as the cart is concerned, the track ''is'' flat.

Similar effects can be achieved when there are ''no'' "downhill" exits to a ramp. This may be the case if you have, for example, an East-West track with a one-tile channel with a ramp in it. The cart will travel through the "dip" with no change in velocity. It can also be the case if you abuse the Track Direction Irrelevance, above, and set only exits ''up'' the ramp, and none leading ''down'' the ramp. For example, if a cart is traveling from West to East up a slope, only carving East exits on each tile of ramp will make the cart travel up the ramp, and then recognize the tile it is on as being a "flat" tile, thus ignoring any deceleration from traveling uphill. Note that this effect only reliably occurs at relatively slow speeds (at around push, or single accelerating ramp speeds) as the cart may simply ignore the ramp and crash into the wall at higher speeds.

=== Skipping ===
If a minecart is moving fast enough, it can skip over [[water]] or [[magma]], making splashes of [[mist]] (or [[magma mist]]) as it attempts to move on them horizontally. This horizontal movement is independent of the minecart and its content's [[weight]].

=== Track Jumping ===
If a minecart encounters the end of the track or a T junction with no "exit" in its movement direction, it will simply leave the track and continue on its course in a straight line until it encounters an obstacle, slows to a stop, or encounters another (properly aligned) Track even if the tile at which it joins the new track instantly sends it around a corner.

Tracks that are travelling at high enough velocity will also start "jumping" the track if it hits an un-tracked tile (flying over and ignoring any tracks) until it is ready to land. Carts that land upon tracked tiles re-rail themselves, and clever designers use this feature to jump over curved track sections in one direction or another. (Retracting bridges over untracked tiles can cause jumps or not cause jumps depending upon the status of the bridge.) Minecart speed must be carefully regulated to ensure reliability of jump length.

Carts that approach a downward slope at a high enough velocity will also make a jump, but will not do so if the Checkpoint Effect (below) is exploited through an impulse ramp before the actual downhill as the impulse ramp "tricks" the cart into thinking it has already started going downhill.

=== Corner Ramp Derail ===

Corners on upward ramps can cause diagonal movement, forcing a derail even if the cart has a wall next to it, which will force a stop when it touches a wall that forces dwarves to manually reset the cart.

This is caused by the fact that a cart, after turning the bend in the track halfway through the length of the tile, will still "accelerate down", which is now perpendicular to the movement of the cart, causing acceleration to occur in two directions. (Down corner ramps do not have this problem, as when they pass the halfway point, all perpendicular motion is added to forward motion, and after that curve, all downward acceleration is in the forward direction.)

There are two fixes to this problem. One is to simply not put corners on up ramps. The other is to take advantage of the Checkpoint Effect, below, by making a ramp (possibly including an impulse ramp) one tile in front of the ramp to make it skip through most of the tile before sideways momentum can be built.

=== Checkpoint Effect ===
The checkpoint effect, [http://www.bay12forums.com/smf/index.php?topic=144328.0 explained in depth by Larix], is an odd and highly exploitable feature of ramps where minecarts "teleport" through the next tile of track, ignoring nearly all minecart physics (except that they stop at all walls or other obstacles and not only respect curves, but will take them even when they would otherwise derail) and passing through that tile in just a single tick, and into the next tile at the halfway point.

This effect occurs when a cart leaves a downward ramp for any other direction of tile. (This includes ramps which accelerate in different directions, even a ramp which goes from accelerating East to accelerating North due to a bend in a chain of standard down ramps in a curve.) This allows, for example, two valid straight ramps directly next to one another with a cart dropped onto one or the other with no momentum to have the cart pick up acceleration going "down" the ramp as normal, but then flying up through the "up" ramp it travels into with no loss of momentum, as though it had come from an impulse ramp. If the two ramps had at least one space of distance between them, and then a cart were dropped in, the cart would instead "rock" back and forth between the two ramps.

This seems to be because ramps have a slightly longer length than regular tiles - 144,000, rather than 100,000 distance. When this "snaps back" after a ramp, it seems to project the cart suddenly further along the track, making it jump a tile ahead even when otherwise moving at relatively low speeds.

This [[bug]] is the cause of a ''wide array'' of unexpected behavior among people who do not take this bug into account. It causes derailments or failure to climb up seemingly valid impulse elevators. In general, it makes a system that behaves extremely counter-intuitively, and operates ''any time a cart encounters a valid ramp''. At the same time, when its effect is accounted for, it is highly exploitable: It causes "perpetual motion devices" using no power when two opposing ramps are placed next to one another, since the "uphill" effect of the opposing ramp is ignored, preventing deceleration.

Another useful thing to note about this exploit is that carts traveling at no less than 72,000 or so speed (enough to travel half a ramp tile in a single tick) can travel through every tile in just one tick at no change in velocity as long as the tiles alternate between impulse ramp or actual down ramp and any other tile type. The cart checkpoints through the non-down-ramp tiles, and can pass through the (impulse) down ramp tiles in a single tick, before they can actually start gaining momentum.

=== Falling ===
When falling, a minecart appears to cause no damage upon collision, possibly to allow cart "stacking" across Z-levels.{{cite devlog|2012|04|06}} A dwarf riding in a minecart that is dropped multiple z-levels suffers normal fall damage. Minecarts can fall through up/down stairs.
The cart falling (from a hatch, thus with no horizontal speed) onto a track ramp is accelerated as if starting from the middle of the ramp - i.e. to the same speed, no matter how many Z-levels it was dropped, vertical velocity is negated. {{cite forum|144328/5701211}}

=== Stacking ===
If a minecart lands on top of another minecart, they may form a stack, with the upper cart on the z-level above the lower. Subsequent carts do not form a stack, but rather quantum stockpile in the same space. This behaviour is useful for [[megaprojects]] and [[trap design]] with minecarts as the weaponry. Moderation should still be exercised: carts take longer to fall into a "stacking" tile already occupied by other carts and will spend that time "hanging" in the air above the stack. This can lead to following carts striking them, which can cause all kinds of malfunctions. The extra time is two game steps for every cart already in the stack, which doesn't hurt stacks of ten carts very much but makes stacks of 100+ rather impractical.

These minecarts on the upper level generally need to be struck with another minecart to move out, or have their support removed. The latter option is safest done by shooting it away with another minecart, manual removal of a stack-supporting cart typically causes the next cart from the stack to [[fun|fall on top]] of the hauler.

=== Perfectly Elastic Collisions ===
Minecart collisions are perfectly elastic, meaning that not only do minecarts not take damage, but that two carts that are rolling which have frontal collisions of near-similar speed, and where one cart is no more than twice the mass of the other cart, will result in a billiard-ball-like effect of the lighter cart bouncing off the heavier cart with a proportional speed increase dependent upon the relative momentum behind the heavier cart.

Using this trick with carts already at the 270,000 maximum speed from ramps can result in "supersonic" carts traveling at speeds in the millions (travelling a dozen tiles per tick), but where they are suddenly subject to 10,000 units of "terminal velocity" friction per tick. [http://www.bay12forums.com/smf/index.php?topic=137557.0 Thread with SCIENCE here].

While hypothetically capable of launching a minecart into orbit when used in conjunction with a ramp, no cargo can be contained in the launched cart, as the collisions will force ejections of the cargo. Your "unwilling volunteer" [[goblin]] space pioneers will simply become paste underneath the wheels of an extreme high-speed cart.

=== Numbers behind the scene ===

According to early research by '''expwnent'''{{cite forum|112831/3536975}}:

The minecart has a variable for speed. Speed is measured in tiles/100000 ticks, so a speed of one hundred thousand means one tile per tick. By going down a large number of ramps, a maximum speed of 270,000 can be reached, which presents the limit for most practical applications. Short bursts of (much) higher speeds are possible through carefully planned collisions of high-speed carts {{cite forum|137557/5145499}}.

Every tick the cart accumulates distance units, as well as slows down depending on current tile (speed is reduced by "friction" of the tile). The cart will move to the next tile the tick before accumulating 100000 distance units, (or several tiles in case of great speed), then the leftover distance units are added to the default 100000 distance u. of the next tile. Since most deceleration and acceleration is applied per step, with the notable exception of corners, a cart going at twice the speed of another one can cover about four times the distance in a straight line, but only twice the distance along a winding track with very many corners.

A push will teleport a cart to the beginning of the next tile (NOT the middle!) in one tick with 19990 speed (10 speed is lost due to track friction), while a roller will give a cart the roller's set speed, and it will start to accumulate regular track friction past the middle of the roller tile. Some track features will affect a minecart when it is past the middle of the previous tile: entering a ramp or a hole/drop will happen when the cart has left the middle of the previous tile, and the ramp will gain additional distance unit depending on the leftover units from the previous tile. When a cart leaves a ramp it will emerge after one tick in the middle of the next regular tile, so its entry coordinate is "50000-speed+friction". Rollers also affect the speed of minecart from the middle of the previous tile.

Friction of tiles:
{| class="wikitable"
|-
! Tile
! Friction
! Comment
|-
| Tracks
| 10
|-
| Ground/Floor
| 200
|-
| Unusable ramp
| 10
|-
| Upwards ramp
| 4910 (10+4900)
|-
| Downwards ramp
| -4890 (10-4900)
|-
| Roller
| ±100000 (but capped by the set speed)
|-
| Corner track
| 10
| Speed reduced by 1000 upon leaving the corner tile
|-
| Track stop (highest)
| 50000
|-
| Track stop (high)
| 10000
|-
| Track stop (medium)
| 500
|-
| Track stop (low)
| 50
|-
| Track stop (lowest)
| 10
|-
| Water 1-6
| Additional (WaterLevel - 1) * 100
| rowspan="2" | [[#Skipping|See Skipping]]
|-
| Magma 1-6
| Additional (WaterLevel - 1) * 500
|-
| Empty space
| 0
|}

Water of depth 7/7 provides a friction of about 10000 per step, as does maximum-depth magma. This higher friction may not apply to very slow-moving carts.

Impulse sources:
{| class="wikitable"
|-
! Feature
! Speed
|-
| Push
| 20000
|-
| Roller lowest
| 10000
|-
| Roller low
| 20000
|-
| Roller medium
| 30000
|-
| Roller high
| 40000
|-
| Roller Highest
| 50000
|-
|}

== Non-standard uses ==
Minecarts include some interesting characteristics that have motivated uses beyond hauling. They can be useful for creating fully-automated [[exploit|quantum stockpiles]] and [[garbage disposal]]s. Storing perishable goods (meat, meals, etc.) inside a minecart appears to guard against rot and vermin.
Minecarts can be [[Trap_design#Minecarts|used as weapons]], or as (hopefully non-fatal) triggers to restart stalled [[healthcare]]. They can also be used to time/control game events, either using a basic [[repeater]] or much more advanced [[minecart logic]].
Minecarts trigger [[pressure plate]]s, which means a trap can be designed to trigger when a thief attempts to steal a minecart.
A pressure plate can be used as automatic and more precise custom "launch when full enough" system - as long as weight of your minecarts stays the same. You cannot build a hatch or roller on the same tile, so launch by bumping with another cart. {{cite forum|15096/4580050}}
Dwarves riding minecarts can attack enemies within reach (which goes back to dev log). This applies to shooting, and they actually can hit targets while riding by.{{cite forum|109460/5266119}} Whether a minecart protects the rider and how it interacts with dodging is not known yet. Minecart riders can also [[Swimming#Minecart_training|train swimming]] and [[Megaprojects#Surveillance_Track|detect ambushers]].

== Adventure mode ==
In addition to being used for hauling, minecarts can also be ridden in [[adventure mode]]. (Adapted from forum thread {{cite forum|122903/4258212}})

# If the minecart is in your inventory, drop it. If it is already on the ground, proceed to step 2.
# Press {{k|u}} when you are 1 tile away from the minecart (or standing on the same tile as the minecart).
# You will be presented with the following options:
[[File:minecart adventure mode menu.png|left]]
{{clear}}
* If you {{DFtext|Push}} the minecart, it will move a few tiles in the direction you chose. Physics comes into play here, so it will gain/lose speed depending on the usual factors.
* If you {{DFtext|Ride}} the minecart, you will hop into the minecart, even if you were a tile away, and it will move in the chosen direction with you in it. It will gain/lose speed depending on the usual factors. Whilst the minecart is in motion, you should press {{k|.}} to skip your turn; if you attempt to move whilst the minecart is still in motion, the laws of physics come into play, and you will take [[wound|damage]]. Alternatively, you can push the minecart whilst it's still in motion (although it's unclear how one can bend [[physics]] so as to push a moving minecart whilst inside the minecart). If you push it in the same direction you are already travelling in, you will greatly increase the minecart's velocity. You can also push it in different directions, and this will cause it to gradually change direction-the amount of pushes this requires depends on the minecart's velocity. Once the minecart has stopped moving, you may move out of it safely, or you may want to give it another push. Note that if you push a minecart right after having ridden it (still on the same tile as the minecart), it will act as though you chose to ''ride'' it.

If you want to test this out without creating an adventurer, the [[object testing arena]] allows you to spawn minecarts ({{k|k}}-{{k|c}}-{{k|n}})

== Forging and Melting ==
* Metal minecarts cost '''two''' [[metal]] bars to forge, or '''six''' [[adamantine]] wafers.
* When a non-adamantine metal minecart is melted down, it will return '''1.8''' metal bars, for an '''efficiency of 90%'''.
* When an adamantine minecart is melted down, it will produce '''1.8''' wafers, for an '''efficiency of 30%'''.

== See also ==
* [http://www.bay12forums.com/smf/index.php?topic=109460.0 The "How Does Minecart" Thread] by '''Girlinhat''' et al.
* [http://www.bay12forums.com/smf/index.php?topic=112831.0 SCIENCE: Quantifying minecart physics] by '''Snaake''' et al.
* [http://www.bay12forums.com/smf/index.php?topic=129676.0 How to build a Multi-cart Ore to Magma Minecart Project without needing power] by '''WanderingKid'''.
* [http://www.bay12forums.com/smf/index.php?topic=144328.0 My very own Minecart Education Thread. Ten Lessons, now complete.] by '''Larix'''.

== Bugs ==
*A dwarf will drop her [[child|baby]], if she has one, when boarding a minecart set to be ridden.
*Dwarves have no concept of traffic safety and will walk into busy minecart lines to retrieve objects, often with deadly consequences. This is especially problematic in [[Swimming#Minecart_training|clever applications]] depending on dwarves riding the carts very frequently, because they have a bad habit of dumping their worn clothes on the tracks after a minecart ride. Adding an automatically-operated [[hatch cover]] at the end of such a ride can help prevent [[unfortunate accident]]s.
*Dwarves cannot guide a minecart through an unlocked door unless another dwarf opens the door.{{bug|6056}}
*It is possible for a creature and minecart moving towards each other to pass without collision if they exchange tiles in the same tick.
*After a minecart ride, a dwarf will sometimes haul the minecart to a storage stockpile, leaving another dwarf to haul the vehicle back to the route.
*Minecarts falling onto a floor injure creatures in the tile below the floor.{{bug|6068}}
*A minecart's initial velocity is not affected by weight, when pushed or launched from rollers.{{bug|6296}}
*Removing a stop that has a vehicle waiting on it may cause the game to crash.{{bug|5980}}

{{Category|Fortress mode}}
{{Category|Interface}}

[[ru:Minecart]]

Minecart

2015-06-18T03:00:09Z

NW Kohaku: /* Impulse ramps */

{{Quality|Masterwork|08:15, 19 May 2015 (UTC)}}
{{av}}
A '''minecart''' is a [[tool]] intended for [[hauling]], introduced in version 0.34.08. It can be made of [[wood]] at a [[carpenter's workshop]] or [[metal]] at a [[metalsmith's forge]] (using the [[Metal crafter|metalcrafting]] labor.) Minecarts store up to five times as many items as [[wheelbarrow]]s and are quite a bit faster than dwarves hauling objects by hand, but have the disadvantages of requiring a dedicated track network, a complex route planning phase, and the possibility of dwarves [[Fun|blundering into the path of carts filled with lead ore]]. Tracks may be carved into stone, or [[Construction|constructed]]; the latter allows above-ground routes, but these are more difficult to set up due to their additional [[building material|material requirements]].

Just like wheelbarrows, minecarts are considered [[item]]s and are stored in a [[furniture]] [[stockpile]]. Despite their five-times-greater capacity, they are only 33% larger than wheelbarrows and are identical in base [[item value|value]] when made from the same [[material]] (the value may differ due to the [[item quality]]). [[thief|Thieves]] or even mischievous animals can steal minecarts, even when they are moving on a track{{cite forum|109460/3289070}}. However, minecarts moving fast enough or being ridden cannot be stolen.

Although most of the utility of minecarts is in [[fortress mode]], an [[adventure mode|adventurer]] can also ride in a minecart. Adventurers can also pick up and relocate minecarts.

The invention of minecarts revolutionized the [[minecart logic|Science of Dwarfputing]] by enabling smaller, faster logic systems to be built.

== Basic Minecart Usage ==
Minecarts can be used to swiftly transport dwarves, [[flow|fluids]], and/or large amounts of items, but before you have a functional minecart there are several preconditions that need to be met. First of all you need an actual minecart, constructed either in a [[carpenter's workshop]] or [[metalsmith's forge]]. For the minecart to be able to move you also need to carve (with {{k|d}} {{k|T}}) or construct (with {{k|b}} {{k|C}} {{k|T}}) a track, which could be as simple as a straight line. Finally you need to construct stops on your track (with {{k|b}} {{k|C}} {{k|S}}) where the minecart will start and stop.

After you have created the stops and assigned a cart to the track, you must create logic routes connecting several stops and designate starting conditions for each stop. This is done with the {{k|h}}auling key. The most basic conditions are how the cart's movement is initiated and in which direction the cart should start moving. Carts can be either be Pushed (a dwarf stands at a stop and gives the cart a single push) or Guided (a dwarf continually pushes the cart forward, guiding it along the track). The [[hauling]] [[labor]] required for pushing and guiding carts is called "Push/Haul Vehicles" and is turned on by default.

To control which items to transport you can add conditions specifying: (1) which kind of items to be loaded, and unloaded, (2) stockpile links to define which stockpile(s) the items should be un/loaded to and from.

===Capacity and weights ===
Minecarts have five times the [[Weight|capacity]] of [[wheelbarrow]]s.

'''Examples of the capacity of one cart'''
{| class="wikitable"
|-
! Item
! Amount
|-
| [[stone]]
| 5
|-
| [[wood|log]]
| 10
|-
| [[block]]/[[bar]]
| 83
|-
| [[Kitchen|prepared meals]]
| 500
|-
| [[Trap_component#Spiked_ball|spiked balls]]
| 500
|-
| [[Weapon#Native_weapons|mace]]
| 625
|-
| [[Weapon#Native_weapons|spears]]
| 1250
|-
| [[cloth]]
| 2500
|}

The weight of the loaded minecart does not affect the initial velocity received from pushing or launching from a roller. However, the load of a minecart ''does'' affect whether a [[pressure plate]] triggers or not, based on the pressure plate's setting.

'''Weights of different carts'''

{| class="wikitable"
|-
! Type of cart
! Empty cart
! Fully loaded (items)
|-
| oaken minecart
| 28Γ
| 378Γ (10 oak logs)
|-
| platinum minecart
| 856Γ
| 10482Γ (83 gold bars)
|}

The weight of a minecart is one twenty-fifth (1/25) the [[density]] of its material in Urists. Because pressure plates can be set to trigger at intervals of 50 Urists, minecarts with weights just under a multiple of 50 are ideal for switching based on whether they're full or empty. The best minecart materials for full/empty switching are as follows:

{| class="wikitable sortable"
|-
! Material !! Minecart weight !! Content weight required to trigger !! Banana roasts required to trigger (for scale)
|-
| [[Bismuth]] (moods only) || 391 || 9 || 15
|-
| [[Brass]] || 342 || 8 || 14
|-
| [[Electrum]] || 596 || 4 || 7
|-
| [[Fine pewter]] || 291 || 9 || 15
|-
| [[Glumprong]] || 48 || 2 || 4
|-
| [[Lay pewter]] || 291 || 9 || 15
|-
| [[Nickel silver]] || 346 || 4 || 7
|-
| [[Tin]] || 291 || 9 || 15
|-
| [[Trifle pewter]] || 291 || 9 || 15
|}

=== Creating tracks ===
Minecart tracks are made up of contiguous track, tracked ramp, or bridge tiles. Track tiles and tracked ramp tiles have a direction or series of directions associated with them. These directions dictate which directions a minecart on a given tile may move from that tile. For example, a Track NE (northeast) tile allows a minecart on it to move either north or east from its present position. Therefore, if you want your minecart to move east along a straight piece of track, then return west using that same track, you would need to use EW tracks so that the cart could travel east initially, then return west over the same track. Excluding designs in which the cart will "jump" tracks via a drop or other ramp, tracks must be valid end to end to work for most looped or straight-track applications. A single east only track tile in your line of east-west tracks will cause any route using the track to fail the moment it tries to go the wrong way over that tile. Minecart tracks can be built in two ways: Engraved/carved or constructed. A given minecart track need not use engraved or constructed elements exclusively, as the two methods can be used interchangeably depending on the needs of a given section of track. The way the tracks are built is slightly different between the two, as explained below.

====Simple tracks====

'''Carved'''

A single-tile wide strip of natural stone can be designated to be [[Engraver|carved]] (with {{K|d}} {{k|T}}), which will create a straight two-way track. The creation of corners, crossings, and T-junctions is as simple as designating another strip of track that overlaps an existent or newly designated track. Engraved tracks are removed by [[smoothing]] the rock they're on, which results in a smooth floor (that can be re-engraved if necessary), or by building a [[floor]] on top and subsequently removing it. Dwarves can carve corner tracks in one pass by designating the track carving twice and canceling unwanted carvings (with {{K|d}} {{K|x}}). Tracks can be engraved in any natural floor tile, rough, smooth and even over engravings, providing an easy method to remove low-quality or undesired floor engravings. Once a track has been engraved, it's important to check the track directions for each tile in the route carefully to make sure no mistakes were made by yourself or the game's track engraving logic.

'''Constructed'''

Tracks can also be built as regular [[construction]]s (through {{K|b}} {{K|C}} {{K|T}}). This method is resource-expensive, since each track tile requires one stone, [[bar]], or [[block]] for construction, and time-consuming, since you can't designate strips longer than 10 tiles at a time. Corners, crossings, T-junctions, and ramps also have to be designated individually. However, it is usually the only way to build tracks above ground or on soil (barring the [[Obsidian farming|creation of obsidian]]). Constructed tracks are designated for removal like any regular construction; be aware that removing track ramps built on top of natural ones will also remove the original ramp, leaving a flat floor.

====Ramps====

'''Carved'''

The carving of natural ramps is a little more confusing: to carve a two-way track on a ramp (natural only, does not work on constructed ramps), you must designate the track '''starting on the ramp and one square beyond''' in the direction you want the track to go. For the side of the ramp square you want to head upward, there '''must''' be either a natural or constructed wall in the square next to it, otherwise the game assumes you are trying to carve it on the same level -- this can result in the track being carved underneath a door or other object. If you have accidentally done this, you can correct it by smoothing the ramp and constructing a single square of wall next to it, then re-carving the ramp correctly. (However, the wall must stay there permanently; removing it will disconnect the track.)

'''Constructed'''

When constructing track ramps, the stated direction should be the same as the connected tracks. For example, a track going up from West to East would require, starting from the West, a Track (EW), a Track/Ramp (EW) and a Wall behind the ramp, underneath the section of track above it. Incorrectly placed ramps result in minecarts ignoring the ramp and crashing into the supporting wall. They will not, however, display as unusable as when the supporting wall is missing.

'''Examples of ramps'''

A simple ramp would look like this:
{{diagram|spaces=yes|\
z +0 z +1
░░░░ ░░░░
═▲o ░▼═
░░░░ ░░░░
o : wall
}}

Carving track corners into ramps is rather unintuitive and complicated. Since engraving tracks always requires two tiles to connect in a straight line as input, you have to give two separate designations for a single job: a track bit from the ramp tile to the "below" direction and another one to the wall of the "upward" direction. If you wanted to change direction on a ramp from east to north:
{{diagram|spaces=yes|\
z +0 z +1
░░░░░ ░░░░░
░░░░░ ══╗░░
=▲░░ ░░▼░░
░░░░░ ░░░░░
}}
you would need to connect the ramp on z +0 both to the west and to the north by issuing two "carve track" commands, one selecting the ramp and the track tile to the west, and another connecting the ramp tile with the wall to the north. An engraver would then carve a NW track corner into the ramp, allowing carts to pass the corner correctly both going up and down. Such track corners are perfectly serviceable for guided carts, but moving down a route of several of them by pushed or ridden cart is problematic - ramps on corners behave very counter-intuitively, resulting in loss of speed when going down and diagonal movement when going up.

Moving to and from ramps (or between ramps "pointing" in different directions0 causes some non-trivial adjustments to speed and even moving along the tiles at a fixed speed ''unrelated to the entry/exit velocity values'', because transitions to/from ramps are processed differently and are not to be "skipped". This affects compact track/ramp combinations (such as e.g. a simple 2x2 ramp spiral) most, and combined with bouncing often makes them work not in the way one could expect. {{cite forum|144328/5705102}}

{{anchor|Tracks}}

=== Hauling route ===
A hauling route is a list of directions describing how and under what conditions a minecart will move. The proper setting up of routes is essential for a working rail system. Routes, stops, departure conditions and stockpile links are managed from the {{k|h}}auling menu.

==== Route ====
A route defines the path a minecart will take along a track, as well as under what conditions it will move or stop moving. A route is made up of stops. Stops are precisely what they sound like, a position on the track at which you want a minecart to stop. A minecart track might use as little as a single stop for a looped track, which will serve as both a starting and stopping point for the cart, or it could contain many stops, perhaps to load supplies or wait for a bridge to be manually lowered, before reaching its destination or returning to its starting point. It is important to note that you only need to place stops on a route where you actually want the cart to stop and wait for some action to occur. They are not needed to help navigate the cart along the track beyond telling it where on the track to stop.

New routes are created with the {{k|h}}auling key. Existing ones can be removed (without confirmation) with the {{k|x}} key, and also {{k|n}}icknamed. Before operating, the route must have a {{k|v}}ehicle assigned to it (this can be done with either the route or a stop selected). Assigning a full minecart to a route may result in a slow hauling job if the contents are heavy.

==== Stops ====
Stops are the individual waypoints that make up a hauling route. A given stop consists of the location of a tile, as well as conditions describing when, where, and how a cart should be moved after being stopped at that tile. Stops can be created from within the {{k|h}}auling menu, by placing the cursor over a tile and hitting {{k|s}} while highlighting the route (or a stop within) you've already designated. A minecart will begin its route at the first stop created, and continue through each subsequent stop, being guided, pushed, or ridden from each stop to the next depending on the conditions specified. In many basic minecart applications, the cart will end up at the same stop it began at, though this is not always the case. It is important to note that hauling stop order is enforced, even if there is no track. A dwarf will drag the cart overland back to a skipped stop in the route's list if your tracks bypass it somehow.

Once a stop has been placed, it is given a default set of conditions under which to move the minecart if it is stopped there. Each new stop gets the same default conditions regardless of the track it is placed upon (e.g. guide the cart to the north). For this reason new stops might get marked by yellow exclamation marks ({{DFtext|!|#ff0}}) due to invalid directions. One important thing to note is that as you place additional stops, the display will show paths between the stops you have defined. However, this is '''not''' necessarily the actual route the minecart will take once the route is in operation. For example, if a route were defined with two stops at opposite ends of a track with many twists and turns, a line will be drawn directly between those stops to show the order in which they will be visited. These route lines may crisscross all over the tracks, but so long as the track is valid end to end, the cart will follow the track from one stop to the next, even across twists, turns, and z-level changes. Stops, which are the steps that make up a route, should not be confused with Track Stops, described below.

===== Stockpile links =====
By placing the cursor on top of a stockpile and using {{k|s}}, you can create stockpile links while defining a hauling stop. Links can also be redefined by selecting them, placing the cursor over a different stockpile, and pressing {{k|p}}. The cart will then be filled by items present in its various linked stockpiles in preference to other items. Note that bins should be used with caution in stockpiles that are linked to minecarts. Bins cause problems when used with the "Desired Items" list in a stop's conditions. For example, if a minecart is set to accept only granite blocks, and to depart north when it is 100% full of granite blocks, it will not depart if any of those granite blocks are in bins, even if bins are also included in the desired items list. Two solutions to this problem exist as of v0.40.24. First, bins can be disallowed in stockpiles that are linked to stops. Alternatively, bins '''can''' be used in conjunction with minecarts provided that the minecart's departure conditions use only "any items" instead of "desired items." This option can be toggled in the advanced conditions menu for a stop, accessible via the {{key|C|}} key. The cart's contents can still be controlled by specifying what items are allowed in the linked stockpile.

===== Departure condition =====
Departure conditions involve setting conditions in which the minecart will leave on the route. Each condition includes:
# A departure mode (Guide, Ride or Push).
# An initial departure direction (NSEW). Note that this defines the initial direction of movement only. Even if a track includes many turns, as long as the initial movement direction is valid the cart will follow the minecart track thereafter.
# A timer, before which the departure condition cannot be met.
# Conditions on the amount of items in the cart.
Departure conditions are created with the {{k|n}} key. A new departure condition will read: "guide north immediately when empty of desired items". This condition can be changed between basic presets with {{k|c}}. "Advanced" mode ({{k|C}}) allows for more precise control over departure conditions: fine tuning the percentage from 0 to 100 in 25% steps ({{k|f}} and {{k|F}}), switching it being either the maximum or the minimum amount of items for the condition to be met ({{k|m}}), and whether the cart accepts all or only a specific set of items ({{k|l}}). Common to both screens are the departure mode ({{k|p}}, Push, Ride or Guide), {{k|d}}irection, and timer ({{k|t}} and {{k|T}}) options.

To have a cart only carry a specific set of items, the stop can be set to only carry "desired" items, opening the selection screen with the {{k|Enter}} key while having said stop condition selected, and toggling as desired, or it can simply be linked to a stockpile and set to depart once it is full of items from its linked stockpiles, regardless of type.

=== Track Stops ===
A Track Stop, not to be confused with a route stop, is an optional, single-tile construction which serves two purposes. First, it can be used to cancel a cart's momentum in order to slow or stop it as it passes over the Track Stop. This might be necessary if a cart were pushed down a series of ramps to its destination. Second, a Track Stop can cause a cart to automatically dump its contents as it passes over the Track Stop. Track Stops are constructed via {{k|b}} {{k|C}} {{k|S}}, and must be constructed atop an existing piece of track. If a Track Stop has been set to automatically dump a cart's contents, the cart will dump its contents in the direction indicated when it passes over the Track Stop. Depending on the friction settings chosen for the Track Stop, the cart might then stop after dumping, or it might continue on its route to another destination.

Track Stops are not mandatory; in fact, their main use is in automated rail systems. However, even in basic rail systems it can be useful to set a Track Stop to dump items: this saves time that dwarves would otherwise spend in removing items from the cart, time that is better spent driving the cart back to where it's needed. Dumping will occur even with a guided cart. '''Take care not to set Track Stops at a loading site to dump their contents''', or dwarves will never be able to fill the cart. It will dump any contents the moment they are loaded.

Counter-intuitive to their construction method, Track Stops are considered [[building]]s and must be removed by {{k|q}} {{k|x}}.
* See [[#More_on_Track_stop |More on Track Stops]]

=== Step-by-step tutorial ===

Let's construct a simple minecart route. This route will move stone blocks from an input stockpile to an output stockpile. We'll begin by creating the stockpiles:

[[File:minecart-example-1.png|Stockpiles designated.]]

The input stockpile is on the left; the output stockpile is on the right. We'll be moving blocks from left to right. Disable bins in both stockpiles, and set the input stockpile to accept only from links. Then make the stockpile take from the mason's workshop where the blocks are being produced.

Next, carve the track:

[[File:minecart-example-2.png|Track carving designation.]]

Note that the ends of the designation are uniquely shaped; this is automatic, and not anything you need to control. Now, wait for your engravers to come along and carve the track into the stone. (Your haulers will probably also fill up the input stockpile while you wait.)

In addition, while we're waiting for that to happen, we'll build an iron minecart in the forge.

[[File:minecart-example-3.png|Track carved.]]

When the track has been carved, it will look like the above (the track will be solid instead of flashing). Now, order a track stop to be constructed next to the output stockpile:

{|
| [[File:minecart-example-4.png|Track stop designation.]]
| [[File:minecart-example-5.png|Select dumping direction.]]
|}

You must press {{k|d}} three times to select the dumping direction ''before'' placing the track stop. We want our blocks to be dumped into the output stockpile east of the track stop. Then wait for a mechanic to come along and build the track stop.

[[File:minecart-example-6.png|Track stop constructed.]]

Now we'll define the actual ''route''. This is done in the {{k|h}}auling menu. Press {{k|r}} to begin defining a route. Next, move the cursor to the input end of the track, and then press {{k|s}} to define the first stop:

{|
| [[File:minecart-example-7.png|Stop 1 designation.]]
| [[File:minecart-example-8.png|Route definition, in progress.]]
|}

Move the cursor again, to the output end of the track, and press {{k|s}} again to define the second stop:

{|
| [[File:minecart-example-9.png|Stop 2 designation.]]
| [[File:minecart-example-10.png|Route definition, two stops.]]
|-
|
| [[File:minecart-example-11.png|Stops are not defined yet.]]
|}

There are several user interface features to note at this point. The stops have been positioned, but they haven't been ''defined'' yet, so there is a warning {{DFtext|!|#ff0}} symbol by each of them. In the lower right corner, we see what the {{DFtext|!|#ff0}} means. Also, note that the second stop is labeled in white, while the other two lines are grey. The white text is a selection indicator, and can be moved up and down by pressing {{k|+}}/{{k|-}}.

Next we need to define what our stops do. We want the minecart to be filled with blocks at the first stop, then travel to the second stop where it will dump its cargo, and then return. Press {{k|-}} to move the selection up to stop 1, and {{k|Enter}} to open it up. By default, the stop has three conditions:

[[File:minecart-example-12.png|Default stop definition.]]

We don't want any of these, so press {{k|x}} three times to delete them. This leaves us with a blank stop. Now we can add the conditions we actually want. Press {{k|n}} to begin adding the first condition, then {{k|d}} twice to change the direction from north to east. Then press {{k|c}} to change the condition from empty to full. This will instruct the minecart to be guided east when full of desired items.

To set the desired items, we create a stockpile link. Press {{k|s}}, then move the cursor to the input stockpile, then press {{k|p}} to select that stockpile. Now press {{k|Enter}}; this opens up a selection screen that resembles the stockpile customization screen. Move down to Blocks, {{k|e}}nable them, then (if you wish) restrict it to stone blocks.

When you've done all that, stop 1 should look like this:

[[File:minecart-example-13.png|Stop 1, defined.]]

Stop 2 is much simpler. All we need to do is have the minecart return to the input stop. So, make a condition and change the direction:

[[File:minecart-example-14.png|Stop 2, defined.]]

Finally, we just have to assign our minecart. Go back to the route definition screen, and press {{k|v}}. Select the minecart, and press {{k|Enter}}.

Now we've got everything set up:

[[File:minecart-example-15.png|Route, fully defined.]]

The V is red because the minecart hasn't been moved onto the track yet. Some dwarf will have to haul it from the forge to the first stop, by hand; this will take a while, especially if the forge is far away.

Once the minecart is in place, dwarves should fill it with blocks from the input stockpile, which will in turn be filled with blocks from the workshop where your mason has been toiling dutifully. When the minecart is full, the blocks will be dumped into the 1x1 stockpile on the right. Automatic quantum dumping!

=== Troubleshooting ===

Because of the complexity of the system, all but the most careful and experienced minecart users will encounter issues. Most route issues can be diagnosed and fixed from the {{k|h}}auling menu.

'''Symptom:''' {{DFtext|! Set dir/connect track|6:1}} message appears to the right of one or more stops

'''Possible Causes:'''
* The departure direction of the stop might be invalid. Edit the stop using {{k|Enter}} and press{{k|d}} until it is pointing in a valid direction.
* The track stop might not be built on top of a track. The track stop must be deconstructed to remedy this issue.
* Your track might not be built correctly. Make sure all connected tracks between destinations are not one-way tracks.
** This can be especially confusing with ramps. To carve a two-way track on a (natural) ramp, you must designate the ramp and one square beyond in the direction you want the track to go.
** Ramps '''must''' have a solid block on the side opposite to the track, or they will neither work nor be marked as "unusable". The solid block can be natural or constructed.
* The desired/kept items might not be configured correctly.

'''Symptom:''' The status '''0% V''' always appears to the right of one stop.

'''Possible Causes:'''
* The stop may not be set to take from a stockpile. Edit the Stop using {{k|Enter}} and make sure you see a message like "Take from Stockpile #1".
* The take conditions must correspond with the contents of the stockpile.
* The track stop may be set to dump. A track stop set to dump cannot be filled. You must either set the stop to a time-based departure or deconstruct the track stop and rebuild it without dumping. (Alternatively, with [[DFHack]] you can modify "Dump on arrival" to "No" using the {{key|q}} menu without rebuilding the stop.)
* Make sure the minecart itself has not been designated to be dumped (such as when using mass-dump).

'''Symptom:''' Dwarves fill the minecart properly, but will not move it thereafter.

'''Possible Causes:'''
* The minecart may contain items which are not included in its current stop's desired items. Check inside the minecart using the {{key|k}} and {{key|z}} keys and ensure that all items in the cart are desired items.
* The minecart may contain desired items in bins. Minecarts seem to have problems realizing that they are in fact full of desired items if some of those items are in bins, even if bins are also among the desired items for that stop. '''This cannot be solved by adding the appropriate bins to the stop's desired items.''' Either disallow bins in stockpiles you intend to load minecarts from, or set the departure conditions to rely only on percentage of total load rather than percentage of desired items using the advanced conditions menu ({{key|C}} key).

'''Symptom:''' Dwarves repeatedly attempt to load the minecart, but no items are ever loaded into it.

'''Possible Causes:'''
* This can be caused by using a Track Stop with autodumping enabled at a loading site. Every time a dwarf places an item into a cart resting on such a track stop, the item will be immediately dumped, causing unlimited, useless cart loading jobs. Autodumping Track Stops should never be used at a loading site.

'''Symptom:''' A dwarf picks up the minecart and carries it to its destination.
* See [[#Quirks|Quirks]]

=== Danger ===
Minecarts are not without <strike>danger</strike> [[fun]]. Although designating a track automatically sets the [[traffic]] designation to low, dwarves ''may'' still walk on them, and [[creature]]s ignore traffic designations altogether. If an unlucky dwarf or creature fails to [[dodger|dodge]] a minecart, they can be injured. Most of this danger can be avoided by setting the minecart {{k|h}}auling commands to guide instead of push or ride (dwarves guiding minecarts will ignore traffic restrictions), as well as by [[pasture|pasturing]] domestic animals and preventing the access of other creatures to the tracks. Note that removing the track doesn't reset that tile back to normal traffic priority, so you may wish to manually clean up traffic designation afterward. Also note that bridges that are used as tracks don't have their traffic priority changed automatically (since they're just normal bridges), which could cause dwarves to pathfind normally through dangerous minecart entrances in your fort's walls if you're not careful.

The only <s>fool</s>''dwarf''-proof method is to make the tracks inaccessible. There are several ways to create a track which works for minecarts but doesn't allow creature-traversal; the simplest is perhaps building a [[statue]] on the tracks. Other options include adding single-tile holes (minecarts moving at reasonable speed will jump the gap), vertical drops, minecart-triggered doors, small pools of liquid (4/7 water or 2/7 magma), and hostile creatures overlooking the tracks. For safety, both ends of the track should be isolated, making the dangerous center sections completely inaccessible (though maintenance access can be provided by a locked door).

Danger does not always involve living victims: careless route designation can also result in minecarts careening off tracks or colliding with each other. If this occurs, the [[item]]s may be scattered; this can cause even more hauling jobs than the minecart aimed to eliminate. Even <s>better</s> worse, scattered items, especially [[weapon]]s, can injure passing [[dwarf|dwarves]] or other [[creature]]s; in the words of Toady One the Great, "Accidental grapeshotting of the dining room should be possible now."

Of course, the danger of using minecarts means they can also be [[Trap_design#Minecarts|used as weapons]] by imaginative players.

== Advanced usage and automation ==
Minecart-specific effects are implemented via track stops, rollers and [[pressure plate]]s with "track" condition set. Since all three are considered [[building]]s, they can't be built on the same square (however convenient track stop + pressure plate would be) nor a simple ramp, and are removed by {{k|q}} {{k|x}}.

=== More on Track stop ===
Track stops are constructions that allow further automation of minecart systems via adjustable features such as braking by friction and automatic dumping of contents. They can be built from logs, bars and blocks through {{K|b}} {{K|C}} {{K|S}}; friction amount, dumping toggle and dumping direction must be set '''before''' construction, and these settings can be neither changed nor seen thereafter; however, track stops can be linked to [[pressure plate]]s or [[lever]]s to toggle friction and dumping On or Off (trigger state is inverted: switch On = track stop Off).

If a [[stockpile]] is placed on the tile that a track stop is set to dump to, it can act as a [[Exploit#Quantum_stockpiles|quantum stockpile]] and any items dumped from a minecart that match the storage settings of the stockpile will remain there and accumulate. Normally trackstops are built on top of existing track to operate on moving minecarts, but they can also be used without tracks to create [[Exploit#The_Minecart_Stop|automatic quantum stockpiles]] (see also [[#Step-by-step_tutorial|step-by-step tutorial]]). It is not always desirable to collect ALL of certain items into one quantum stockpile, such as when distributing a material to multiple separate industries. You can link your quantum stockpile to various other stockpiles, ensuring that your dwarves will keep them supplied as necessary. Because quantum stockpiles never fill up like regular stockpiles, it may be a good idea to add a switch to turn them off.

Items dumped from a minecart at a track stop (or dumped by any other means) into open space fall through z-levels until they land on a solid surface. Items falling onto a designated [[stockpile]] will automatically be considered part of that stockpile, even if the stockpile is set to disallow those items (they will, however, be automatically moved to a more appropriate stockpile, if available). Items falling on top of a minecart will '''not''' fall "inside" the minecart. Use with caution; dwarves have fragile skulls.{{bug|5945}}

=== Automated propulsion ===
==== Roller ====
{{Main|Roller}}

A '''roller''' is a [[power]]ed [[machine component]] for the automated propulsion of minecarts. They are built over the top of existing tracks with {{K|b|M|r}}, requiring a [[mechanic]], ''(length/4)+1'' [[mechanism]]s and a [[rope]]. Rollers may also be placed directly on ramps to help pull carts up Z levels. Rollers are very useful to maintain a cart's momentum along long routes, to get them to climb Z-levels without dwarfpower involved, and to get them to reach speeds unattainable by guiding dwarves. These devices are variable-length (1-10), variable-direction and variable-speed ([[Minecart#Numbers_behind_the_scene|see below]]), all traits that can be set at construction time; a roller uses two units of power per tile it is long.

Single-tile rollers transfer power in all four cardinal directions, while other rollers generally only transfer power perpendicular to their activity direction. Longer rollers can also transfer power along their activity direction if built in the correct order, although this can be hard to accomplish and is easily broken. Rollers cannot be powered from above.

Rollers have great acceleration and capped speed. Carts going faster than the roller are unaffected. If a cart moves across an active roller in the direction the roller works and moves slower than the roller's specified speed, the cart will be set to the roller's speed. A cart going against a roller's movement direction will be sent back the way it came (once again at the roller's speed), unless it was moving extremely fast: speed increment of 100000 allows to reverse carts from the full "highest" (50000) speed roller to full "highest" speed back, but ramps can accelerate a cart beyond this. {{cite forum|144328/5702453}}
A cart crossing over a roller perpendicular to its current movement direction will gain the roller's amount of speed in the perpendicular direction without directly changing its forward motion. Without an adjacent wall to constrict its movement, this will typically send a cart off the rails on a diagonal path, completely unable to follow any tracks until it collides with a wall or is otherwise brought to rest. However, if the roller is placed over a track turn and pushes ''from'' the direction of that turn's track, the turn affects carts ''after'' the roller, so they will be forced into the turn rather than derailed in a diagonal direction. {{cite forum|144328/5702453}}

{{diagram|spaces=yes|\
tracks: full:
║ ║
═╗═ ═╢═
║ ║

╢ : roller pushing from W to E
}}
If the roller is powered, carts from ''all'' directions (unless too fast) exit S, because speed imparted by the roller forces carts toward E and ''then'' into the turn.
If not powered, carts from W and N exit S, carts from E and S exit W. Carts above derail speed will ignore the turn, of course.

{{diagram|spaces=yes|\
║ ║
═╗═ ═╟═
║ ║

╟ : Roller pushing from E to W
}}
Carts from the E or W: exit W.
Carts from N: derailed diagonally, exit SW.
Carts from S: derailed diagonally, exit NW.

Rollers affects carts on a track - if placed on a floor or ramp without any tracks, they are ignored. Depowered rollers are also ignored, friction is determined by the tiles underneath.

Because of their one-way nature, rollers are unsuitable for most two-way minecart tracks (unless you set gears toggling roller A->B off while toggling A<-B rollers on). However, a minecart set to be ''guided'' is not affected by rollers at all{{cite forum|109460/3286235}} — this allows a one-way track to be used in both directions. In addition, unpowered rollers do not affect minecarts.

Care must be taken in [[glacier]]s and other extremely cold [[biome]]s, since rollers (and the machinery used to power them) will not operate when constructed on natural [[ice]] floors.

==== Impulse ramps ====
Carts can be given momentum without rollers or changing z-level through a phenomenon called "impulse ramps". A track ramp which is connected both to a wall and to a floor will ''always'' accelerate a cart towards the connected floor tile, no matter where the cart enters the tile from. This means carts can be accelerated as though dropping z-levels, even if the cart doesn't actually change z-level at all. If a track ramp faces three directions such as ╩, then two of those directions need to be facing walls for the cart to be accelerated towards the remaining direction.

Example of straight impulse acceleration:

{{diagram|spaces=yes|\
▒▒▒▒▒▒▒▒▒▒ ▒▒▒▒▒▒▒▒▒▒
═▲▲▲▲▲▲▲▲▲▲═ ═╚╚╚╚╚╚╚╚╚╚═
▒ : Wall
═ : Normal track
▲/╚ : N/E Track/Ramp
}}

If a cart enters from the left, it will speed up on every track/ramp and exit to the right going very very fast - more than one tile every step. If it enters from the right then it will bounce back impulsed by the ramp if it's going slow enough.

As another oddity, carts coming from ramps will in some cases "teleport" through most of the next tile. This can be used to send carts up levels with minimal loss of speed. You can just make an upward spiral alternating impulse ramps and regular upward ramps. It takes no power, is quick and cheap to build, requiring only channeling and track carving, and the cart goes up fast, but not so fast that it launches its contents.

Example of an impulse elevator:

{{diagram|spaces=yes|\
z +0 z +1 z +2 z +3
░░░░░ ░░░░░ ░░░░░ ░░░░░
░╔░░░ ░▼╚╗░ ░░▼▼░ ░░░░░
░╝░░░ ░▼░░░ ░░░╔░ ░░░▼░
░▼▼░░ ░░░░░ ░░░╝░ ░╚╗▼░
░░░░░ ░░░░░ ░░░░░ ░░░░░

░ : Wall
╔,╚,╗,╝ : Track/Ramp
▼ : Down Ramp (empty space)
}}

Note that this impulse elevator, due to the checkpoint effect and upward ramp curve effect, will not actually result in carts traveling straight up the ramp. They will lose speed, bounce off a ramp, then be accelerated back into the spiral after a 9-turn delay on both tiles on the floor where they are stopped. This is because the checkpoint effect allows carts to travel up the ramps in a single turn, but also prevents the impulse ramps from adding acceleration unless the cart is slowed to staying on the ramp for more than one turn. Initial acceleration will carry the cart up a variable number of floors before this effect occurs, but this bouncing back and forth will occur every 5z-levels after the first time the cart stops. When the cart ''is'' traveling upwards, it will pass every tile at a rate of one tile per turn regardless of its actual speed, due to the checkpoint effect. In tracks with only a single cart, this is negligible, but when multiple carts are on the same track (such as when you place multiple carts on a magma cart lift) this can cause collisions which derail carts or cause other unexpected or undesired behaviors.

The following impulse ramp (while larger) should alleviate these problems with additional impulse ramps that actually have enough time (more than one turn) to add speed (although a derail checkpoint may be required to prevent excessive speeds):

{{diagram|spaces=yes|\
z +0 z +1 z +2 z +3
░░░░░░ ░░░░░░ ░░░░░░ ░░░░░░
░╔░░░░ ░▼╚╚╗░ ░░▼▼▼░ ░░░░░░
░╝░░░░ ░▼░░░░ ░░░░╔░ ░░░░▼░
░╝░░░░ ░▼░░░░ ░░░░╔░ ░░░░▼░
░▼▼▼░░ ░░░░░░ ░░░░╝░ ░╚╗╗▼░
░░░░░░ ░░░░░░ ░░░░░░ ░░░░░░

░ : Wall
╔,╚,╗,╝ : Track/Ramp
▼ : Down Ramp (empty space)
}}

A sort of opposite effect to impulse ramps also exists: ramps lacking the proper "up" and "down" connections are treated as flat track, even if they actually go up or down z-levels. This allows building "anti-impulse" slopes consisting entirely of ramps only connected up, which a minecart can travel up forty levels and more, needing no more than a single push.

=== Controlling traffic ===

==== Switching ====

As constructions or tile features, [[door]]s and other furniture can be built on tracks. A [[door]] or [[floodgate]] can be turned on or off by a [[lever]], effectively controlling the flow of automated minecarts. This may be <s>dangerous</s> [[fun]], however.
{{diagram|spaces=yes|\
->
A ════┤≡════ B
┤ : roller pushing to East
≡ : door
}}
The roller pushes the cart east, but until the "departure condition" is fulfilled, the door remains closed and blocks the path.

[[Bridge]]s can also act as tracks, but only if they're lowered or not retracted. This property can enable levers to turn tracks on and off. However, care should be taken to ensure that such bridges are never operated while a cart is on top of them, as the cart will be flung off the track. It's worth noting that it's often faster, and cheaper, to construct large bridges than long sections of constructed track.

A powered track switch can be constructed by building an "inverted" corner as illustrated below.
{{diagram|spaces=yes|\
B B
║ -> ║
║ ║
════╚═══ ════├════
A C A C
├ : roller pushing to West.
}}

If the cart is pushed East from the stop at 'A' while the roller is activated, it will arrive at 'B'. If the roller is not running, it will arrive at 'C'. The switch works by the roller first reversing the incoming cart's movement and the cart ''then'' following the track corner.

This switch is very reliable, reacts instantly to on/off signals, and carts of any speed can be switched by this design, although very fast carts will require rollers that are several tiles long, up to three. The requirement for power can be inconvenient or impractical. Non-powered solutions may use controlled derailment, or a connecting bridge.
{{diagram|spaces=yes|\
B ╥
║
║
╞════╝ ════╡
A D C
}}
Here the track between A and C is not continuous. The only continuous track is A->B, with a corner (not a T section). Fast moving carts will tend to derail at D and rejoin the track to C. Placing a door at D will prevent the derailment, so the cart continues to B. The door is operated by mechanisms elsewhere (typically, a lever, but some fun can be had with pressure plates).

Since it depends on derailing, this switch requires a very fast cart, faster than what can be achieved with rollers alone. To gain sufficient speed, a cart must be accelerated further, usually by descending several levels or through impulse ramps. The high speed makes the cart much more dangerous and harder to control.

If carts are moving too slowly to derail at the corner, a retractable bridge may be used as a connector between A and C.
{{diagram|spaces=yes|\
B╥
║
║
A╞════bbb════╡C
}}
The bridge must overlap the corner. Bridges behave like a track crossing, allowing carts to pass in a straight line. When retracted, the corner reappears, so the carts will continue to B. Bridges take 100 steps to react to a signal, necessitating rather long "lead times" when switching tracks via bridge.

As mentioned above, special care must be taken to make sure the bridge doesn't change state while the cart is passing over it. Retracting bridges will throw the cart, causing it to stop dead. Raising bridges can even crush the cart.

==== Controlling Speed ====


Minecarts can reach extremely high speeds, especially when descending multiple Z-levels. A minecart will derail at a track corner if its speed exceeds 0.5 t/st (tiles per step), '''unless''' the route in the direction of travel is blocked:

Will derail at > 0.5 t/st:

{{diagram|spaces=yes|\
in ══╗ -> derailing
║
out
}}

Will not derail at > 0.5 t/st:
{{diagram|spaces=yes|\
in ══╗O
║
out

O : wall/column.
}}

This behavior can be used to build a "speed limiter", that will ensure that when a minecart exits it is traveling below derail speed:
{{diagram|spaces=yes|\
░░░░ ░░░░░ ░░░░░
in ═╔═╗░ ░╔S╗░ ░╔S╗░
out ═╬═╝░ out ═╗═╝░ out ═╗═╝░
░╚S╝░ ░╚═╝═ in ░╚S╝░
░░░░░ ░░░░ ║░░░
in
░ : wall
S : Track Stop (High Friction or lower)
}}
If the minecart is traveling below derailment speed, it will not be affected; if above, will be slowed down and checked again. Granted, you could do the same just with track turns, but it may take a lot of turns and time.

Since all the derailings, bounces and ramps can impart a sideway component of speed small enough to start visible drift many tiles away (say, [[Fun|in the middle of a bridge]]), track turns have one more use: forcing the carts to move strictly along the grid directions. Carts passing a turn below derailing speed convert one component of velocity into another, thus eliminating the drift.

=== Loading liquids ===
[[Water]] and [[magma]] can also be loaded into minecarts by submerging them to a depth of at least 6/7 while standing still or moving at speeds of at most 10000. Loading fluids onto minecarts can be difficult because the added friction provided by fluids can stop a cart in a submerged tile. Curiously, filling a minecart with magma does not injure a dwarf ''riding'' it. A minecart will hold enough fluid to increase the depth of a single tile by 2. This amount is listed as 833 units, which weigh 459Γ (water) or 999Γ (magma). An iron or steel cart filled with magma weighs 1313Γ, while an adamantine cart filled with magma weighs 1007Γ. Since you need a minecart above the liquid's level, possible arrangements may include pressure-activated sluices, rollers (with magma-safe chains for magma), pouring from above to "submerge" it briefly on the same level and drain excess away (dig deeper and leave a vaporizer, though if you could have power for rollers, may as well use a pump) and exploits with ramps (not necessarily impulse ramps, "same height" passing dip does it).
The liquids can be dumped by a constructed track stop.

== Quirks ==
This little quirk concerns dwarf-managed minecarts. If a track which was previously open becomes blocked (ex. flipping a switch connected to a floodgate you've built on the track to raise it) and the conditions for departure are met, instead of refusing to ride/guide the minecart or ride/guide it until it reaches the obstacle, the dwarf will pick up the minecart off the tracks and haul it to its scheduled destination on foot. If the distance is long enough and the weight of the cart heavy enough (due to being filled with heavy items such as stones), the dwarf may drop the cart because of fatigue/hunger/thirst before reaching the destination. This will cancel that vehicle setting job and make another dwarf come by and attempt to haul the cart to the nearest appropriate stockpile where another dwarf will pick up the cart and attempt to haul it to its initial stop. If the stockpile is far enough from initial stop, this second dwarf who is attempting to place the minecart on its tracks may also drop the minecart out of fatigue/hunger/thirst creating a loop that will go on until a dwarf with enough endurance manages to place the minecart where it belongs.

In fact, it seems dwarves are more than happy to attempt to carry a minecart from one stop to another even if just waiting until the track is open again would be the more sane option.

Dwarves will also carry a minecart to its next stop if the direction specified is incorrect (or invalid). This can often occur when using the default departure settings and forgetting to set the direction of each condition.

Dwarves can admire buildings while riding mine carts. Dwarves will not fall asleep during a ride (at least not from being drowsy). If riding on a continuous powered track loop, the dwarf will die of dehydration/starvation as they can not jump off to get sustenance{{cite forum|109460/3377228}}. Dwarves riding in submerged minecarts will gain experience in [[swimming]].{{cite forum|129889}}

Tracks block wagon access to trade depots, unless they're on a ramp. [[Bridge]]s can also be used, as they function as tracks but do not block wagons.

== Physics ==


Minecart physics depend greatly on the departure mode set in the route stop conditions.

When set to "Push" or "Ride", minecarts will move according to the regular laws of momentum, gaining speed when going downhill, losing it slowly due to friction when on a flat plane, and more quickly when going uphill. In these modes, minecarts will move in a straight line until they either are brought to a stop by friction or an obstacle, or until they encounter a turn. A minecart will roll straight past "blocked" ends of T-junctions or track ends, they have no power to restrict a cart's movement. The cart's behavior is largely independent of the weight of its contents (including fluids and dwarves): heavily loaded carts gain more momentum when accelerating, but this only plays a role in collisions: a heavy cart gains just as much speed and is as easy to stop as a light one. In either case, dwarves can not push nor ride an unpowered cart up a ramp, bouncing back the direction it came. At best, this is a waste of time; at worst, it will give your cart-pushing dwarf a [[fun|fun surprise]]. To solve this, the player can either use Rollers (see below) or set the cart to be Guided.

The difference between "Push" and "Ride" is whether the dwarf will go along with the cart or not.
{{DFtext|Push}}: the dwarf will give the cart an initial push, not enough to go up a ramp, but enough to go some way along flat track, and the dwarf will remain at the first stop, ready for a new job.
{{DFtext|Ride}}: the dwarf will give the cart the same initial push and then hop aboard the cart riding with it to the next stop.
{{DFtext|Guide}}: minecarts seem to ignore all laws of physics. That is:
*Ignore the weight of any and all items inside. Therefore:
**Move at the speed of the dwarf that is guiding them. It is thus recommended to pick the most [[attribute#Agility|agile]] of your dwarves for cart-guiding tasks.
*Ignore working rollers.
*Will ''not'' collide with other guided carts even when a full frontal collision would be expected.
*Will go up ramps like nobody's business.
This is therefore the recommended method of transport for simple non-powered rail systems, despite it diverting a dwarf from other, potentially more important tasks.

Some samples with behavior:
{{diagram|spaces=yes|\
A <-> B A <-> C A <-> B
B B B
║ ║ ║
A══╝ A══╩══C A══╬╗
You can only go A->B ╚╝
Works when the cart Works
is in Guide mode.
}}
In the second example above, a cart "pushed" from B will go over the junction and roll off into the unknown south.

=== Track Direction Irrelevance ===
Carts that are traveling independently, (that is, not guided,) only care that tracks ''are'' on the tile, not which direction the tracks actually move. Tracks respect only curves (with two exits) and ramps.

This means, for example, that the following tracks, when a (non-guided) cart travels from West-to-East, are functionally identical in effect:

A════════════B A╬║╚╔╣╩╦╠╥╨╞╡B

This is because so far as the cart is concerned, only ramps and curves with two exits where the exit in the path they are traveling matters.

Carts only check for curves when they are halfway through a tile. When they get there, they look to see if their path has no exit. (That is, if it is traveling East, it checks if there is an East exit.) If there is, it ignores all other track directions, and keeps traveling. If there is not, it checks to see if there are only two exits to the track, and if one of those directions was the direction it "came from". (That is, if traveling from the East, it checks if there is a valid exit to the West, and if so, if there is either a North exit or a South exit.) If there is not, it ignores the track anyway, and keeps on traveling as though it were still on track. If there is, it will subtract 1000 from the velocity of the cart, and redirect all forward velocity to the direction of the curve. This change in the direction of velocity ''overwrites'' any "diagonal" velocity, which can prevent diagonal velocity derailments, but any perpendicular velocity is not preserved, and is instead discarded.

=== Invalid Ramps ===
Ramps are functionally defined for cart purposes as being a tile which exerts an acceleration force upon its "downward slope". This downward slope requires a cart to have one ''and exactly one'' carved exit to the tile that is the "bottom" of the ramp. Ramps push carts in this "downward" direction (possibly leading to diagonal movement, below), and the deceleration of an "uphill" ramp is actually just the acceleration being applied against the direction of a cart's movement.

This is where players can find an exploit in the behavior of ramps - if there are ''two'' "downhill" exits to a ramp (such as a "T junction" on a ramp where only one exit faces a wall), then the ramp provides no acceleration ''or'' deceleration, allowing carts to travel up ramps without any loss of momentum except for the standard "flat track" deceleration, because as far as the cart is concerned, the track ''is'' flat.

Similar effects can be achieved when there are ''no'' "downhill" exits to a ramp. This may be the case if you have, for example, an East-West track with a one-tile channel with a ramp in it. The cart will travel through the "dip" with no change in velocity. It can also be the case if you abuse the Track Direction Irrelevance, above, and set only exits ''up'' the ramp, and none leading ''down'' the ramp. For example, if a cart is traveling from West to East up a slope, only carving East exits on each tile of ramp will make the cart travel up the ramp, and then recognize the tile it is on as being a "flat" tile, thus ignoring any deceleration from traveling uphill. Note that this effect only reliably occurs at relatively slow speeds (at around push, or single accelerating ramp speeds) as the cart may simply ignore the ramp and crash into the wall at higher speeds.

=== Skipping ===
If a minecart is moving fast enough, it can skip over [[water]] or [[magma]], making splashes of [[mist]] (or [[magma mist]]) as it attempts to move on them horizontally. This horizontal movement is independent of the minecart and its content's [[weight]].

=== Track Jumping ===
If a minecart encounters the end of the track or a T junction with no "exit" in its movement direction, it will simply leave the track and continue on its course in a straight line until it encounters an obstacle, slows to a stop, or encounters another (properly aligned) Track even if the tile at which it joins the new track instantly sends it around a corner.

Tracks that are travelling at high enough velocity will also start "jumping" the track if it hits an un-tracked tile (flying over and ignoring any tracks) until it is ready to land. Carts that land upon tracked tiles re-rail themselves, and clever designers use this feature to jump over curved track sections in one direction or another. (Retracting bridges over untracked tiles can cause jumps or not cause jumps depending upon the status of the bridge.) Minecart speed must be carefully regulated to ensure reliability of jump length.

Carts that approach a downward slope at a high enough velocity will also make a jump, but will not do so if the Checkpoint Effect (below) is exploited through an impulse ramp before the actual downhill as the impulse ramp "tricks" the cart into thinking it has already started going downhill.

=== Corner Ramp Derail ===

Corners on upward ramps can cause diagonal movement, forcing a derail even if the cart has a wall next to it, which will force a stop when it touches a wall that forces dwarves to manually reset the cart.

This is caused by the fact that a cart, after turning the bend in the track halfway through the length of the tile, will still "accelerate down", which is now perpendicular to the movement of the cart, causing acceleration to occur in two directions. (Down corner ramps do not have this problem, as when they pass the halfway point, all perpendicular motion is added to forward motion, and after that curve, all downward acceleration is in the forward direction.)

There are two fixes to this problem. One is to simply not put corners on up ramps. The other is to take advantage of the Checkpoint Effect, below, by making a ramp (possibly including an impulse ramp) one tile in front of the ramp to make it skip through most of the tile before sideways momentum can be built.

=== Checkpoint Effect ===
The checkpoint effect, [http://www.bay12forums.com/smf/index.php?topic=144328.0 explained in depth by Larix], is an odd and highly exploitable feature of ramps where minecarts "teleport" through the next tile of track, ignoring nearly all minecart physics (except that they stop at all walls or other obstacles and not only respect curves, but will take them even when they would otherwise derail) and passing through that tile in just a single tick, and into the next tile at the halfway point.

This effect occurs when a cart leaves a downward ramp for any other direction of tile. (This includes ramps which accelerate in different directions, even a ramp which goes from accelerating East to accelerating North due to a bend in a chain of standard down ramps in a curve.) This allows, for example, two valid straight ramps directly next to one another with a cart dropped onto one or the other with no momentum to have the cart pick up acceleration going "down" the ramp as normal, but then flying up through the "up" ramp it travels into with no loss of momentum, as though it had come from an impulse ramp. If the two ramps had at least one space of distance between them, and then a cart were dropped in, the cart would instead "rock" back and forth between the two ramps.

This seems to be because ramps have a slightly longer length than regular tiles - 144,000, rather than 100,000 distance. When this "snaps back" after a ramp, it seems to project the cart suddenly further along the track, making it jump a tile ahead even when otherwise moving at relatively low speeds.

This [[bug]] is the cause of a ''wide array'' of unexpected behavior among people who do not take this bug into account. It causes derailments or failure to climb up seemingly valid impulse elevators. In general, it makes a system that behaves extremely counter-intuitively, and operates ''any time a cart encounters a valid ramp''. At the same time, when its effect is accounted for, it is highly exploitable: It causes "perpetual motion devices" using no power when two opposing ramps are placed next to one another, since the "uphill" effect of the opposing ramp is ignored, preventing deceleration.

Another useful thing to note about this exploit is that carts traveling at no less than 72,000 or so speed (enough to travel half a ramp tile in a single tick) can travel through every tile in just one tick at no change in velocity as long as the tiles alternate between impulse ramp or actual down ramp and any other tile type. The cart checkpoints through the non-down-ramp tiles, and can pass through the (impulse) down ramp tiles in a single tick, before they can actually start gaining momentum.

=== Falling ===
When falling, a minecart appears to cause no damage upon collision, possibly to allow cart "stacking" across Z-levels.{{cite devlog|2012|04|06}} A dwarf riding in a minecart that is dropped multiple z-levels suffers normal fall damage. Minecarts can fall through up/down stairs.
The cart falling (from a hatch, thus with no horizontal speed) onto a track ramp is accelerated as if starting from the middle of the ramp - i.e. to the same speed, no matter how many Z-levels it was dropped, vertical velocity is negated. {{cite forum|144328/5701211}}

=== Stacking ===
If a minecart lands on top of another minecart, they may form a stack, with the upper cart on the z-level above the lower. Subsequent carts do not form a stack, but rather quantum stockpile in the same space. This behaviour is useful for [[megaprojects]] and [[trap design]] with minecarts as the weaponry. Moderation should still be exercised: carts take longer to fall into a "stacking" tile already occupied by other carts and will spend that time "hanging" in the air above the stack. This can lead to following carts striking them, which can cause all kinds of malfunctions. The extra time is two game steps for every cart already in the stack, which doesn't hurt stacks of ten carts very much but makes stacks of 100+ rather impractical.

These minecarts on the upper level generally need to be struck with another minecart to move out, or have their support removed. The latter option is safest done by shooting it away with another minecart, manual removal of a stack-supporting cart typically causes the next cart from the stack to [[fun|fall on top]] of the hauler.

=== Perfectly Elastic Collisions ===
Minecart collisions are perfectly elastic, meaning that not only do minecarts not take damage, but that two carts that are rolling which have frontal collisions of near-similar speed, and where one cart is no more than twice the mass of the other cart, will result in a billiard-ball-like effect of the lighter cart bouncing off the heavier cart with a proportional speed increase dependent upon the relative momentum behind the heavier cart.

Using this trick with carts already at the 270,000 maximum speed from ramps can result in "supersonic" carts traveling at speeds in the millions (travelling a dozen tiles per tick), but where they are suddenly subject to 10,000 units of "terminal velocity" friction per tick. [http://www.bay12forums.com/smf/index.php?topic=137557.0 Thread with SCIENCE here].

While hypothetically capable of launching a minecart into orbit when used in conjunction with a ramp, no cargo can be contained in the launched cart, as the collisions will force ejections of the cargo. Your "unwilling volunteer" [[goblin]] space pioneers will simply become paste underneath the wheels of an extreme high-speed cart.

=== Numbers behind the scene ===

According to early research by '''expwnent'''{{cite forum|112831/3536975}}:

The minecart has a variable for speed. Speed is measured in tiles/100000 ticks, so a speed of one hundred thousand means one tile per tick. By going down a large number of ramps, a maximum speed of 270,000 can be reached, which presents the limit for most practical applications. Short bursts of (much) higher speeds are possible through carefully planned collisions of high-speed carts {{cite forum|137557/5145499}}.

Every tick the cart accumulates distance units, as well as slows down depending on current tile (speed is reduced by "friction" of the tile). The cart will move to the next tile the tick before accumulating 100000 distance units, (or several tiles in case of great speed), then the leftover distance units are added to the default 100000 distance u. of the next tile. Since most deceleration and acceleration is applied per step, with the notable exception of corners, a cart going at twice the speed of another one can cover about four times the distance in a straight line, but only twice the distance along a winding track with very many corners.

A push will teleport a cart to the beginning of the next tile (NOT the middle!) in one tick with 19990 speed (10 speed is lost due to track friction), while a roller will give a cart the roller's set speed, and it will start to accumulate regular track friction past the middle of the roller tile. Some track features will affect a minecart when it is past the middle of the previous tile: entering a ramp or a hole/drop will happen when the cart has left the middle of the previous tile, and the ramp will gain additional distance unit depending on the leftover units from the previous tile. When a cart leaves a ramp it will emerge after one tick in the middle of the next regular tile, so its entry coordinate is "50000-speed+friction". Rollers also affect the speed of minecart from the middle of the previous tile.

Friction of tiles:
{| class="wikitable"
|-
! Tile
! Friction
! Comment
|-
| Tracks
| 10
|-
| Ground/Floor
| 200
|-
| Unusable ramp
| 10
|-
| Upwards ramp
| 4910 (10+4900)
|-
| Downwards ramp
| -4890 (10-4900)
|-
| Roller
| ±100000 (but capped by the set speed)
|-
| Corner track
| 10
| Speed reduced by 1000 upon leaving the corner tile
|-
| Track stop (highest)
| 50000
|-
| Track stop (high)
| 10000
|-
| Track stop (medium)
| 500
|-
| Track stop (low)
| 50
|-
| Track stop (lowest)
| 10
|-
| Water 1-6
| Additional (WaterLevel - 1) * 100
| rowspan="2" | [[#Skipping|See Skipping]]
|-
| Magma 1-6
| Additional (WaterLevel - 1) * 500
|-
| Empty space
| 0
|}

Water of depth 7/7 provides a friction of about 10000 per step, as does maximum-depth magma. This higher friction may not apply to very slow-moving carts.

Impulse sources:
{| class="wikitable"
|-
! Feature
! Speed
|-
| Push
| 20000
|-
| Roller lowest
| 10000
|-
| Roller low
| 20000
|-
| Roller medium
| 30000
|-
| Roller high
| 40000
|-
| Roller Highest
| 50000
|-
|}

== Non-standard uses ==
Minecarts include some interesting characteristics that have motivated uses beyond hauling. They can be useful for creating fully-automated [[exploit|quantum stockpiles]] and [[garbage disposal]]s. Storing perishable goods (meat, meals, etc.) inside a minecart appears to guard against rot and vermin.
Minecarts can be [[Trap_design#Minecarts|used as weapons]], or as (hopefully non-fatal) triggers to restart stalled [[healthcare]]. They can also be used to time/control game events, either using a basic [[repeater]] or much more advanced [[minecart logic]].
Minecarts trigger [[pressure plate]]s, which means a trap can be designed to trigger when a thief attempts to steal a minecart.
A pressure plate can be used as automatic and more precise custom "launch when full enough" system - as long as weight of your minecarts stays the same. You cannot build a hatch or roller on the same tile, so launch by bumping with another cart. {{cite forum|15096/4580050}}
Dwarves riding minecarts can attack enemies within reach (which goes back to dev log). This applies to shooting, and they actually can hit targets while riding by.{{cite forum|109460/5266119}} Whether a minecart protects the rider and how it interacts with dodging is not known yet. Minecart riders can also [[Swimming#Minecart_training|train swimming]] and [[Megaprojects#Surveillance_Track|detect ambushers]].

== Adventure mode ==
In addition to being used for hauling, minecarts can also be ridden in [[adventure mode]]. (Adapted from forum thread {{cite forum|122903/4258212}})

# If the minecart is in your inventory, drop it. If it is already on the ground, proceed to step 2.
# Press {{k|u}} when you are 1 tile away from the minecart (or standing on the same tile as the minecart).
# You will be presented with the following options:
[[File:minecart adventure mode menu.png|left]]
{{clear}}
* If you {{DFtext|Push}} the minecart, it will move a few tiles in the direction you chose. Physics comes into play here, so it will gain/lose speed depending on the usual factors.
* If you {{DFtext|Ride}} the minecart, you will hop into the minecart, even if you were a tile away, and it will move in the chosen direction with you in it. It will gain/lose speed depending on the usual factors. Whilst the minecart is in motion, you should press {{k|.}} to skip your turn; if you attempt to move whilst the minecart is still in motion, the laws of physics come into play, and you will take [[wound|damage]]. Alternatively, you can push the minecart whilst it's still in motion (although it's unclear how one can bend [[physics]] so as to push a moving minecart whilst inside the minecart). If you push it in the same direction you are already travelling in, you will greatly increase the minecart's velocity. You can also push it in different directions, and this will cause it to gradually change direction-the amount of pushes this requires depends on the minecart's velocity. Once the minecart has stopped moving, you may move out of it safely, or you may want to give it another push. Note that if you push a minecart right after having ridden it (still on the same tile as the minecart), it will act as though you chose to ''ride'' it.

If you want to test this out without creating an adventurer, the [[object testing arena]] allows you to spawn minecarts ({{k|k}}-{{k|c}}-{{k|n}})

== Forging and Melting ==
* Metal minecarts cost '''two''' [[metal]] bars to forge, or '''six''' [[adamantine]] wafers.
* When a non-adamantine metal minecart is melted down, it will return '''1.8''' metal bars, for an '''efficiency of 90%'''.
* When an adamantine minecart is melted down, it will produce '''1.8''' wafers, for an '''efficiency of 30%'''.

== See also ==
* [http://www.bay12forums.com/smf/index.php?topic=109460.0 The "How Does Minecart" Thread] by '''Girlinhat''' et al.
* [http://www.bay12forums.com/smf/index.php?topic=112831.0 SCIENCE: Quantifying minecart physics] by '''Snaake''' et al.
* [http://www.bay12forums.com/smf/index.php?topic=129676.0 How to build a Multi-cart Ore to Magma Minecart Project without needing power] by '''WanderingKid'''.
* [http://www.bay12forums.com/smf/index.php?topic=144328.0 My very own Minecart Education Thread. Ten Lessons, now complete.] by '''Larix'''.

== Bugs ==
*A dwarf will drop her [[child|baby]], if she has one, when boarding a minecart set to be ridden.
*Dwarves have no concept of traffic safety and will walk into busy minecart lines to retrieve objects, often with deadly consequences. This is especially problematic in [[Swimming#Minecart_training|clever applications]] depending on dwarves riding the carts very frequently, because they have a bad habit of dumping their worn clothes on the tracks after a minecart ride. Adding an automatically-operated [[hatch cover]] at the end of such a ride can help prevent [[unfortunate accident]]s.
*Dwarves cannot guide a minecart through an unlocked door unless another dwarf opens the door.{{bug|6056}}
*It is possible for a creature and minecart moving towards each other to pass without collision if they exchange tiles in the same tick.
*After a minecart ride, a dwarf will sometimes haul the minecart to a storage stockpile, leaving another dwarf to haul the vehicle back to the route.
*Minecarts falling onto a floor injure creatures in the tile below the floor.{{bug|6068}}
*A minecart's initial velocity is not affected by weight, when pushed or launched from rollers.{{bug|6296}}
*Removing a stop that has a vehicle waiting on it may cause the game to crash.{{bug|5980}}

{{Category|Fortress mode}}
{{Category|Interface}}

[[ru:Minecart]]

Minecart

2015-06-18T02:51:45Z

NW Kohaku: /* Impulse ramps */

{{Quality|Masterwork|08:15, 19 May 2015 (UTC)}}
{{av}}
A '''minecart''' is a [[tool]] intended for [[hauling]], introduced in version 0.34.08. It can be made of [[wood]] at a [[carpenter's workshop]] or [[metal]] at a [[metalsmith's forge]] (using the [[Metal crafter|metalcrafting]] labor.) Minecarts store up to five times as many items as [[wheelbarrow]]s and are quite a bit faster than dwarves hauling objects by hand, but have the disadvantages of requiring a dedicated track network, a complex route planning phase, and the possibility of dwarves [[Fun|blundering into the path of carts filled with lead ore]]. Tracks may be carved into stone, or [[Construction|constructed]]; the latter allows above-ground routes, but these are more difficult to set up due to their additional [[building material|material requirements]].

Just like wheelbarrows, minecarts are considered [[item]]s and are stored in a [[furniture]] [[stockpile]]. Despite their five-times-greater capacity, they are only 33% larger than wheelbarrows and are identical in base [[item value|value]] when made from the same [[material]] (the value may differ due to the [[item quality]]). [[thief|Thieves]] or even mischievous animals can steal minecarts, even when they are moving on a track{{cite forum|109460/3289070}}. However, minecarts moving fast enough or being ridden cannot be stolen.

Although most of the utility of minecarts is in [[fortress mode]], an [[adventure mode|adventurer]] can also ride in a minecart. Adventurers can also pick up and relocate minecarts.

The invention of minecarts revolutionized the [[minecart logic|Science of Dwarfputing]] by enabling smaller, faster logic systems to be built.

== Basic Minecart Usage ==
Minecarts can be used to swiftly transport dwarves, [[flow|fluids]], and/or large amounts of items, but before you have a functional minecart there are several preconditions that need to be met. First of all you need an actual minecart, constructed either in a [[carpenter's workshop]] or [[metalsmith's forge]]. For the minecart to be able to move you also need to carve (with {{k|d}} {{k|T}}) or construct (with {{k|b}} {{k|C}} {{k|T}}) a track, which could be as simple as a straight line. Finally you need to construct stops on your track (with {{k|b}} {{k|C}} {{k|S}}) where the minecart will start and stop.

After you have created the stops and assigned a cart to the track, you must create logic routes connecting several stops and designate starting conditions for each stop. This is done with the {{k|h}}auling key. The most basic conditions are how the cart's movement is initiated and in which direction the cart should start moving. Carts can be either be Pushed (a dwarf stands at a stop and gives the cart a single push) or Guided (a dwarf continually pushes the cart forward, guiding it along the track). The [[hauling]] [[labor]] required for pushing and guiding carts is called "Push/Haul Vehicles" and is turned on by default.

To control which items to transport you can add conditions specifying: (1) which kind of items to be loaded, and unloaded, (2) stockpile links to define which stockpile(s) the items should be un/loaded to and from.

===Capacity and weights ===
Minecarts have five times the [[Weight|capacity]] of [[wheelbarrow]]s.

'''Examples of the capacity of one cart'''
{| class="wikitable"
|-
! Item
! Amount
|-
| [[stone]]
| 5
|-
| [[wood|log]]
| 10
|-
| [[block]]/[[bar]]
| 83
|-
| [[Kitchen|prepared meals]]
| 500
|-
| [[Trap_component#Spiked_ball|spiked balls]]
| 500
|-
| [[Weapon#Native_weapons|mace]]
| 625
|-
| [[Weapon#Native_weapons|spears]]
| 1250
|-
| [[cloth]]
| 2500
|}

The weight of the loaded minecart does not affect the initial velocity received from pushing or launching from a roller. However, the load of a minecart ''does'' affect whether a [[pressure plate]] triggers or not, based on the pressure plate's setting.

'''Weights of different carts'''

{| class="wikitable"
|-
! Type of cart
! Empty cart
! Fully loaded (items)
|-
| oaken minecart
| 28Γ
| 378Γ (10 oak logs)
|-
| platinum minecart
| 856Γ
| 10482Γ (83 gold bars)
|}

The weight of a minecart is one twenty-fifth (1/25) the [[density]] of its material in Urists. Because pressure plates can be set to trigger at intervals of 50 Urists, minecarts with weights just under a multiple of 50 are ideal for switching based on whether they're full or empty. The best minecart materials for full/empty switching are as follows:

{| class="wikitable sortable"
|-
! Material !! Minecart weight !! Content weight required to trigger !! Banana roasts required to trigger (for scale)
|-
| [[Bismuth]] (moods only) || 391 || 9 || 15
|-
| [[Brass]] || 342 || 8 || 14
|-
| [[Electrum]] || 596 || 4 || 7
|-
| [[Fine pewter]] || 291 || 9 || 15
|-
| [[Glumprong]] || 48 || 2 || 4
|-
| [[Lay pewter]] || 291 || 9 || 15
|-
| [[Nickel silver]] || 346 || 4 || 7
|-
| [[Tin]] || 291 || 9 || 15
|-
| [[Trifle pewter]] || 291 || 9 || 15
|}

=== Creating tracks ===
Minecart tracks are made up of contiguous track, tracked ramp, or bridge tiles. Track tiles and tracked ramp tiles have a direction or series of directions associated with them. These directions dictate which directions a minecart on a given tile may move from that tile. For example, a Track NE (northeast) tile allows a minecart on it to move either north or east from its present position. Therefore, if you want your minecart to move east along a straight piece of track, then return west using that same track, you would need to use EW tracks so that the cart could travel east initially, then return west over the same track. Excluding designs in which the cart will "jump" tracks via a drop or other ramp, tracks must be valid end to end to work for most looped or straight-track applications. A single east only track tile in your line of east-west tracks will cause any route using the track to fail the moment it tries to go the wrong way over that tile. Minecart tracks can be built in two ways: Engraved/carved or constructed. A given minecart track need not use engraved or constructed elements exclusively, as the two methods can be used interchangeably depending on the needs of a given section of track. The way the tracks are built is slightly different between the two, as explained below.

====Simple tracks====

'''Carved'''

A single-tile wide strip of natural stone can be designated to be [[Engraver|carved]] (with {{K|d}} {{k|T}}), which will create a straight two-way track. The creation of corners, crossings, and T-junctions is as simple as designating another strip of track that overlaps an existent or newly designated track. Engraved tracks are removed by [[smoothing]] the rock they're on, which results in a smooth floor (that can be re-engraved if necessary), or by building a [[floor]] on top and subsequently removing it. Dwarves can carve corner tracks in one pass by designating the track carving twice and canceling unwanted carvings (with {{K|d}} {{K|x}}). Tracks can be engraved in any natural floor tile, rough, smooth and even over engravings, providing an easy method to remove low-quality or undesired floor engravings. Once a track has been engraved, it's important to check the track directions for each tile in the route carefully to make sure no mistakes were made by yourself or the game's track engraving logic.

'''Constructed'''

Tracks can also be built as regular [[construction]]s (through {{K|b}} {{K|C}} {{K|T}}). This method is resource-expensive, since each track tile requires one stone, [[bar]], or [[block]] for construction, and time-consuming, since you can't designate strips longer than 10 tiles at a time. Corners, crossings, T-junctions, and ramps also have to be designated individually. However, it is usually the only way to build tracks above ground or on soil (barring the [[Obsidian farming|creation of obsidian]]). Constructed tracks are designated for removal like any regular construction; be aware that removing track ramps built on top of natural ones will also remove the original ramp, leaving a flat floor.

====Ramps====

'''Carved'''

The carving of natural ramps is a little more confusing: to carve a two-way track on a ramp (natural only, does not work on constructed ramps), you must designate the track '''starting on the ramp and one square beyond''' in the direction you want the track to go. For the side of the ramp square you want to head upward, there '''must''' be either a natural or constructed wall in the square next to it, otherwise the game assumes you are trying to carve it on the same level -- this can result in the track being carved underneath a door or other object. If you have accidentally done this, you can correct it by smoothing the ramp and constructing a single square of wall next to it, then re-carving the ramp correctly. (However, the wall must stay there permanently; removing it will disconnect the track.)

'''Constructed'''

When constructing track ramps, the stated direction should be the same as the connected tracks. For example, a track going up from West to East would require, starting from the West, a Track (EW), a Track/Ramp (EW) and a Wall behind the ramp, underneath the section of track above it. Incorrectly placed ramps result in minecarts ignoring the ramp and crashing into the supporting wall. They will not, however, display as unusable as when the supporting wall is missing.

'''Examples of ramps'''

A simple ramp would look like this:
{{diagram|spaces=yes|\
z +0 z +1
░░░░ ░░░░
═▲o ░▼═
░░░░ ░░░░
o : wall
}}

Carving track corners into ramps is rather unintuitive and complicated. Since engraving tracks always requires two tiles to connect in a straight line as input, you have to give two separate designations for a single job: a track bit from the ramp tile to the "below" direction and another one to the wall of the "upward" direction. If you wanted to change direction on a ramp from east to north:
{{diagram|spaces=yes|\
z +0 z +1
░░░░░ ░░░░░
░░░░░ ══╗░░
=▲░░ ░░▼░░
░░░░░ ░░░░░
}}
you would need to connect the ramp on z +0 both to the west and to the north by issuing two "carve track" commands, one selecting the ramp and the track tile to the west, and another connecting the ramp tile with the wall to the north. An engraver would then carve a NW track corner into the ramp, allowing carts to pass the corner correctly both going up and down. Such track corners are perfectly serviceable for guided carts, but moving down a route of several of them by pushed or ridden cart is problematic - ramps on corners behave very counter-intuitively, resulting in loss of speed when going down and diagonal movement when going up.

Moving to and from ramps (or between ramps "pointing" in different directions0 causes some non-trivial adjustments to speed and even moving along the tiles at a fixed speed ''unrelated to the entry/exit velocity values'', because transitions to/from ramps are processed differently and are not to be "skipped". This affects compact track/ramp combinations (such as e.g. a simple 2x2 ramp spiral) most, and combined with bouncing often makes them work not in the way one could expect. {{cite forum|144328/5705102}}

{{anchor|Tracks}}

=== Hauling route ===
A hauling route is a list of directions describing how and under what conditions a minecart will move. The proper setting up of routes is essential for a working rail system. Routes, stops, departure conditions and stockpile links are managed from the {{k|h}}auling menu.

==== Route ====
A route defines the path a minecart will take along a track, as well as under what conditions it will move or stop moving. A route is made up of stops. Stops are precisely what they sound like, a position on the track at which you want a minecart to stop. A minecart track might use as little as a single stop for a looped track, which will serve as both a starting and stopping point for the cart, or it could contain many stops, perhaps to load supplies or wait for a bridge to be manually lowered, before reaching its destination or returning to its starting point. It is important to note that you only need to place stops on a route where you actually want the cart to stop and wait for some action to occur. They are not needed to help navigate the cart along the track beyond telling it where on the track to stop.

New routes are created with the {{k|h}}auling key. Existing ones can be removed (without confirmation) with the {{k|x}} key, and also {{k|n}}icknamed. Before operating, the route must have a {{k|v}}ehicle assigned to it (this can be done with either the route or a stop selected). Assigning a full minecart to a route may result in a slow hauling job if the contents are heavy.

==== Stops ====
Stops are the individual waypoints that make up a hauling route. A given stop consists of the location of a tile, as well as conditions describing when, where, and how a cart should be moved after being stopped at that tile. Stops can be created from within the {{k|h}}auling menu, by placing the cursor over a tile and hitting {{k|s}} while highlighting the route (or a stop within) you've already designated. A minecart will begin its route at the first stop created, and continue through each subsequent stop, being guided, pushed, or ridden from each stop to the next depending on the conditions specified. In many basic minecart applications, the cart will end up at the same stop it began at, though this is not always the case. It is important to note that hauling stop order is enforced, even if there is no track. A dwarf will drag the cart overland back to a skipped stop in the route's list if your tracks bypass it somehow.

Once a stop has been placed, it is given a default set of conditions under which to move the minecart if it is stopped there. Each new stop gets the same default conditions regardless of the track it is placed upon (e.g. guide the cart to the north). For this reason new stops might get marked by yellow exclamation marks ({{DFtext|!|#ff0}}) due to invalid directions. One important thing to note is that as you place additional stops, the display will show paths between the stops you have defined. However, this is '''not''' necessarily the actual route the minecart will take once the route is in operation. For example, if a route were defined with two stops at opposite ends of a track with many twists and turns, a line will be drawn directly between those stops to show the order in which they will be visited. These route lines may crisscross all over the tracks, but so long as the track is valid end to end, the cart will follow the track from one stop to the next, even across twists, turns, and z-level changes. Stops, which are the steps that make up a route, should not be confused with Track Stops, described below.

===== Stockpile links =====
By placing the cursor on top of a stockpile and using {{k|s}}, you can create stockpile links while defining a hauling stop. Links can also be redefined by selecting them, placing the cursor over a different stockpile, and pressing {{k|p}}. The cart will then be filled by items present in its various linked stockpiles in preference to other items. Note that bins should be used with caution in stockpiles that are linked to minecarts. Bins cause problems when used with the "Desired Items" list in a stop's conditions. For example, if a minecart is set to accept only granite blocks, and to depart north when it is 100% full of granite blocks, it will not depart if any of those granite blocks are in bins, even if bins are also included in the desired items list. Two solutions to this problem exist as of v0.40.24. First, bins can be disallowed in stockpiles that are linked to stops. Alternatively, bins '''can''' be used in conjunction with minecarts provided that the minecart's departure conditions use only "any items" instead of "desired items." This option can be toggled in the advanced conditions menu for a stop, accessible via the {{key|C|}} key. The cart's contents can still be controlled by specifying what items are allowed in the linked stockpile.

===== Departure condition =====
Departure conditions involve setting conditions in which the minecart will leave on the route. Each condition includes:
# A departure mode (Guide, Ride or Push).
# An initial departure direction (NSEW). Note that this defines the initial direction of movement only. Even if a track includes many turns, as long as the initial movement direction is valid the cart will follow the minecart track thereafter.
# A timer, before which the departure condition cannot be met.
# Conditions on the amount of items in the cart.
Departure conditions are created with the {{k|n}} key. A new departure condition will read: "guide north immediately when empty of desired items". This condition can be changed between basic presets with {{k|c}}. "Advanced" mode ({{k|C}}) allows for more precise control over departure conditions: fine tuning the percentage from 0 to 100 in 25% steps ({{k|f}} and {{k|F}}), switching it being either the maximum or the minimum amount of items for the condition to be met ({{k|m}}), and whether the cart accepts all or only a specific set of items ({{k|l}}). Common to both screens are the departure mode ({{k|p}}, Push, Ride or Guide), {{k|d}}irection, and timer ({{k|t}} and {{k|T}}) options.

To have a cart only carry a specific set of items, the stop can be set to only carry "desired" items, opening the selection screen with the {{k|Enter}} key while having said stop condition selected, and toggling as desired, or it can simply be linked to a stockpile and set to depart once it is full of items from its linked stockpiles, regardless of type.

=== Track Stops ===
A Track Stop, not to be confused with a route stop, is an optional, single-tile construction which serves two purposes. First, it can be used to cancel a cart's momentum in order to slow or stop it as it passes over the Track Stop. This might be necessary if a cart were pushed down a series of ramps to its destination. Second, a Track Stop can cause a cart to automatically dump its contents as it passes over the Track Stop. Track Stops are constructed via {{k|b}} {{k|C}} {{k|S}}, and must be constructed atop an existing piece of track. If a Track Stop has been set to automatically dump a cart's contents, the cart will dump its contents in the direction indicated when it passes over the Track Stop. Depending on the friction settings chosen for the Track Stop, the cart might then stop after dumping, or it might continue on its route to another destination.

Track Stops are not mandatory; in fact, their main use is in automated rail systems. However, even in basic rail systems it can be useful to set a Track Stop to dump items: this saves time that dwarves would otherwise spend in removing items from the cart, time that is better spent driving the cart back to where it's needed. Dumping will occur even with a guided cart. '''Take care not to set Track Stops at a loading site to dump their contents''', or dwarves will never be able to fill the cart. It will dump any contents the moment they are loaded.

Counter-intuitive to their construction method, Track Stops are considered [[building]]s and must be removed by {{k|q}} {{k|x}}.
* See [[#More_on_Track_stop |More on Track Stops]]

=== Step-by-step tutorial ===

Let's construct a simple minecart route. This route will move stone blocks from an input stockpile to an output stockpile. We'll begin by creating the stockpiles:

[[File:minecart-example-1.png|Stockpiles designated.]]

The input stockpile is on the left; the output stockpile is on the right. We'll be moving blocks from left to right. Disable bins in both stockpiles, and set the input stockpile to accept only from links. Then make the stockpile take from the mason's workshop where the blocks are being produced.

Next, carve the track:

[[File:minecart-example-2.png|Track carving designation.]]

Note that the ends of the designation are uniquely shaped; this is automatic, and not anything you need to control. Now, wait for your engravers to come along and carve the track into the stone. (Your haulers will probably also fill up the input stockpile while you wait.)

In addition, while we're waiting for that to happen, we'll build an iron minecart in the forge.

[[File:minecart-example-3.png|Track carved.]]

When the track has been carved, it will look like the above (the track will be solid instead of flashing). Now, order a track stop to be constructed next to the output stockpile:

{|
| [[File:minecart-example-4.png|Track stop designation.]]
| [[File:minecart-example-5.png|Select dumping direction.]]
|}

You must press {{k|d}} three times to select the dumping direction ''before'' placing the track stop. We want our blocks to be dumped into the output stockpile east of the track stop. Then wait for a mechanic to come along and build the track stop.

[[File:minecart-example-6.png|Track stop constructed.]]

Now we'll define the actual ''route''. This is done in the {{k|h}}auling menu. Press {{k|r}} to begin defining a route. Next, move the cursor to the input end of the track, and then press {{k|s}} to define the first stop:

{|
| [[File:minecart-example-7.png|Stop 1 designation.]]
| [[File:minecart-example-8.png|Route definition, in progress.]]
|}

Move the cursor again, to the output end of the track, and press {{k|s}} again to define the second stop:

{|
| [[File:minecart-example-9.png|Stop 2 designation.]]
| [[File:minecart-example-10.png|Route definition, two stops.]]
|-
|
| [[File:minecart-example-11.png|Stops are not defined yet.]]
|}

There are several user interface features to note at this point. The stops have been positioned, but they haven't been ''defined'' yet, so there is a warning {{DFtext|!|#ff0}} symbol by each of them. In the lower right corner, we see what the {{DFtext|!|#ff0}} means. Also, note that the second stop is labeled in white, while the other two lines are grey. The white text is a selection indicator, and can be moved up and down by pressing {{k|+}}/{{k|-}}.

Next we need to define what our stops do. We want the minecart to be filled with blocks at the first stop, then travel to the second stop where it will dump its cargo, and then return. Press {{k|-}} to move the selection up to stop 1, and {{k|Enter}} to open it up. By default, the stop has three conditions:

[[File:minecart-example-12.png|Default stop definition.]]

We don't want any of these, so press {{k|x}} three times to delete them. This leaves us with a blank stop. Now we can add the conditions we actually want. Press {{k|n}} to begin adding the first condition, then {{k|d}} twice to change the direction from north to east. Then press {{k|c}} to change the condition from empty to full. This will instruct the minecart to be guided east when full of desired items.

To set the desired items, we create a stockpile link. Press {{k|s}}, then move the cursor to the input stockpile, then press {{k|p}} to select that stockpile. Now press {{k|Enter}}; this opens up a selection screen that resembles the stockpile customization screen. Move down to Blocks, {{k|e}}nable them, then (if you wish) restrict it to stone blocks.

When you've done all that, stop 1 should look like this:

[[File:minecart-example-13.png|Stop 1, defined.]]

Stop 2 is much simpler. All we need to do is have the minecart return to the input stop. So, make a condition and change the direction:

[[File:minecart-example-14.png|Stop 2, defined.]]

Finally, we just have to assign our minecart. Go back to the route definition screen, and press {{k|v}}. Select the minecart, and press {{k|Enter}}.

Now we've got everything set up:

[[File:minecart-example-15.png|Route, fully defined.]]

The V is red because the minecart hasn't been moved onto the track yet. Some dwarf will have to haul it from the forge to the first stop, by hand; this will take a while, especially if the forge is far away.

Once the minecart is in place, dwarves should fill it with blocks from the input stockpile, which will in turn be filled with blocks from the workshop where your mason has been toiling dutifully. When the minecart is full, the blocks will be dumped into the 1x1 stockpile on the right. Automatic quantum dumping!

=== Troubleshooting ===

Because of the complexity of the system, all but the most careful and experienced minecart users will encounter issues. Most route issues can be diagnosed and fixed from the {{k|h}}auling menu.

'''Symptom:''' {{DFtext|! Set dir/connect track|6:1}} message appears to the right of one or more stops

'''Possible Causes:'''
* The departure direction of the stop might be invalid. Edit the stop using {{k|Enter}} and press{{k|d}} until it is pointing in a valid direction.
* The track stop might not be built on top of a track. The track stop must be deconstructed to remedy this issue.
* Your track might not be built correctly. Make sure all connected tracks between destinations are not one-way tracks.
** This can be especially confusing with ramps. To carve a two-way track on a (natural) ramp, you must designate the ramp and one square beyond in the direction you want the track to go.
** Ramps '''must''' have a solid block on the side opposite to the track, or they will neither work nor be marked as "unusable". The solid block can be natural or constructed.
* The desired/kept items might not be configured correctly.

'''Symptom:''' The status '''0% V''' always appears to the right of one stop.

'''Possible Causes:'''
* The stop may not be set to take from a stockpile. Edit the Stop using {{k|Enter}} and make sure you see a message like "Take from Stockpile #1".
* The take conditions must correspond with the contents of the stockpile.
* The track stop may be set to dump. A track stop set to dump cannot be filled. You must either set the stop to a time-based departure or deconstruct the track stop and rebuild it without dumping. (Alternatively, with [[DFHack]] you can modify "Dump on arrival" to "No" using the {{key|q}} menu without rebuilding the stop.)
* Make sure the minecart itself has not been designated to be dumped (such as when using mass-dump).

'''Symptom:''' Dwarves fill the minecart properly, but will not move it thereafter.

'''Possible Causes:'''
* The minecart may contain items which are not included in its current stop's desired items. Check inside the minecart using the {{key|k}} and {{key|z}} keys and ensure that all items in the cart are desired items.
* The minecart may contain desired items in bins. Minecarts seem to have problems realizing that they are in fact full of desired items if some of those items are in bins, even if bins are also among the desired items for that stop. '''This cannot be solved by adding the appropriate bins to the stop's desired items.''' Either disallow bins in stockpiles you intend to load minecarts from, or set the departure conditions to rely only on percentage of total load rather than percentage of desired items using the advanced conditions menu ({{key|C}} key).

'''Symptom:''' Dwarves repeatedly attempt to load the minecart, but no items are ever loaded into it.

'''Possible Causes:'''
* This can be caused by using a Track Stop with autodumping enabled at a loading site. Every time a dwarf places an item into a cart resting on such a track stop, the item will be immediately dumped, causing unlimited, useless cart loading jobs. Autodumping Track Stops should never be used at a loading site.

'''Symptom:''' A dwarf picks up the minecart and carries it to its destination.
* See [[#Quirks|Quirks]]

=== Danger ===
Minecarts are not without <strike>danger</strike> [[fun]]. Although designating a track automatically sets the [[traffic]] designation to low, dwarves ''may'' still walk on them, and [[creature]]s ignore traffic designations altogether. If an unlucky dwarf or creature fails to [[dodger|dodge]] a minecart, they can be injured. Most of this danger can be avoided by setting the minecart {{k|h}}auling commands to guide instead of push or ride (dwarves guiding minecarts will ignore traffic restrictions), as well as by [[pasture|pasturing]] domestic animals and preventing the access of other creatures to the tracks. Note that removing the track doesn't reset that tile back to normal traffic priority, so you may wish to manually clean up traffic designation afterward. Also note that bridges that are used as tracks don't have their traffic priority changed automatically (since they're just normal bridges), which could cause dwarves to pathfind normally through dangerous minecart entrances in your fort's walls if you're not careful.

The only <s>fool</s>''dwarf''-proof method is to make the tracks inaccessible. There are several ways to create a track which works for minecarts but doesn't allow creature-traversal; the simplest is perhaps building a [[statue]] on the tracks. Other options include adding single-tile holes (minecarts moving at reasonable speed will jump the gap), vertical drops, minecart-triggered doors, small pools of liquid (4/7 water or 2/7 magma), and hostile creatures overlooking the tracks. For safety, both ends of the track should be isolated, making the dangerous center sections completely inaccessible (though maintenance access can be provided by a locked door).

Danger does not always involve living victims: careless route designation can also result in minecarts careening off tracks or colliding with each other. If this occurs, the [[item]]s may be scattered; this can cause even more hauling jobs than the minecart aimed to eliminate. Even <s>better</s> worse, scattered items, especially [[weapon]]s, can injure passing [[dwarf|dwarves]] or other [[creature]]s; in the words of Toady One the Great, "Accidental grapeshotting of the dining room should be possible now."

Of course, the danger of using minecarts means they can also be [[Trap_design#Minecarts|used as weapons]] by imaginative players.

== Advanced usage and automation ==
Minecart-specific effects are implemented via track stops, rollers and [[pressure plate]]s with "track" condition set. Since all three are considered [[building]]s, they can't be built on the same square (however convenient track stop + pressure plate would be) nor a simple ramp, and are removed by {{k|q}} {{k|x}}.

=== More on Track stop ===
Track stops are constructions that allow further automation of minecart systems via adjustable features such as braking by friction and automatic dumping of contents. They can be built from logs, bars and blocks through {{K|b}} {{K|C}} {{K|S}}; friction amount, dumping toggle and dumping direction must be set '''before''' construction, and these settings can be neither changed nor seen thereafter; however, track stops can be linked to [[pressure plate]]s or [[lever]]s to toggle friction and dumping On or Off (trigger state is inverted: switch On = track stop Off).

If a [[stockpile]] is placed on the tile that a track stop is set to dump to, it can act as a [[Exploit#Quantum_stockpiles|quantum stockpile]] and any items dumped from a minecart that match the storage settings of the stockpile will remain there and accumulate. Normally trackstops are built on top of existing track to operate on moving minecarts, but they can also be used without tracks to create [[Exploit#The_Minecart_Stop|automatic quantum stockpiles]] (see also [[#Step-by-step_tutorial|step-by-step tutorial]]). It is not always desirable to collect ALL of certain items into one quantum stockpile, such as when distributing a material to multiple separate industries. You can link your quantum stockpile to various other stockpiles, ensuring that your dwarves will keep them supplied as necessary. Because quantum stockpiles never fill up like regular stockpiles, it may be a good idea to add a switch to turn them off.

Items dumped from a minecart at a track stop (or dumped by any other means) into open space fall through z-levels until they land on a solid surface. Items falling onto a designated [[stockpile]] will automatically be considered part of that stockpile, even if the stockpile is set to disallow those items (they will, however, be automatically moved to a more appropriate stockpile, if available). Items falling on top of a minecart will '''not''' fall "inside" the minecart. Use with caution; dwarves have fragile skulls.{{bug|5945}}

=== Automated propulsion ===
==== Roller ====
{{Main|Roller}}

A '''roller''' is a [[power]]ed [[machine component]] for the automated propulsion of minecarts. They are built over the top of existing tracks with {{K|b|M|r}}, requiring a [[mechanic]], ''(length/4)+1'' [[mechanism]]s and a [[rope]]. Rollers may also be placed directly on ramps to help pull carts up Z levels. Rollers are very useful to maintain a cart's momentum along long routes, to get them to climb Z-levels without dwarfpower involved, and to get them to reach speeds unattainable by guiding dwarves. These devices are variable-length (1-10), variable-direction and variable-speed ([[Minecart#Numbers_behind_the_scene|see below]]), all traits that can be set at construction time; a roller uses two units of power per tile it is long.

Single-tile rollers transfer power in all four cardinal directions, while other rollers generally only transfer power perpendicular to their activity direction. Longer rollers can also transfer power along their activity direction if built in the correct order, although this can be hard to accomplish and is easily broken. Rollers cannot be powered from above.

Rollers have great acceleration and capped speed. Carts going faster than the roller are unaffected. If a cart moves across an active roller in the direction the roller works and moves slower than the roller's specified speed, the cart will be set to the roller's speed. A cart going against a roller's movement direction will be sent back the way it came (once again at the roller's speed), unless it was moving extremely fast: speed increment of 100000 allows to reverse carts from the full "highest" (50000) speed roller to full "highest" speed back, but ramps can accelerate a cart beyond this. {{cite forum|144328/5702453}}
A cart crossing over a roller perpendicular to its current movement direction will gain the roller's amount of speed in the perpendicular direction without directly changing its forward motion. Without an adjacent wall to constrict its movement, this will typically send a cart off the rails on a diagonal path, completely unable to follow any tracks until it collides with a wall or is otherwise brought to rest. However, if the roller is placed over a track turn and pushes ''from'' the direction of that turn's track, the turn affects carts ''after'' the roller, so they will be forced into the turn rather than derailed in a diagonal direction. {{cite forum|144328/5702453}}

{{diagram|spaces=yes|\
tracks: full:
║ ║
═╗═ ═╢═
║ ║

╢ : roller pushing from W to E
}}
If the roller is powered, carts from ''all'' directions (unless too fast) exit S, because speed imparted by the roller forces carts toward E and ''then'' into the turn.
If not powered, carts from W and N exit S, carts from E and S exit W. Carts above derail speed will ignore the turn, of course.

{{diagram|spaces=yes|\
║ ║
═╗═ ═╟═
║ ║

╟ : Roller pushing from E to W
}}
Carts from the E or W: exit W.
Carts from N: derailed diagonally, exit SW.
Carts from S: derailed diagonally, exit NW.

Rollers affects carts on a track - if placed on a floor or ramp without any tracks, they are ignored. Depowered rollers are also ignored, friction is determined by the tiles underneath.

Because of their one-way nature, rollers are unsuitable for most two-way minecart tracks (unless you set gears toggling roller A->B off while toggling A<-B rollers on). However, a minecart set to be ''guided'' is not affected by rollers at all{{cite forum|109460/3286235}} — this allows a one-way track to be used in both directions. In addition, unpowered rollers do not affect minecarts.

Care must be taken in [[glacier]]s and other extremely cold [[biome]]s, since rollers (and the machinery used to power them) will not operate when constructed on natural [[ice]] floors.

==== Impulse ramps ====
Carts can be given momentum without rollers or changing z-level through a phenomenon called "impulse ramps". A track ramp which is connected both to a wall and to a floor will ''always'' accelerate a cart towards the connected floor tile, no matter where the cart enters the tile from. This means carts can be accelerated as though dropping z-levels, even if the cart doesn't actually change z-level at all. If a track ramp faces three directions such as ╩, then two of those directions need to be facing walls for the cart to be accelerated towards the remaining direction.

Example of straight impulse acceleration:

{{diagram|spaces=yes|\
▒▒▒▒▒▒▒▒▒▒ ▒▒▒▒▒▒▒▒▒▒
═▲▲▲▲▲▲▲▲▲▲═ ═╚╚╚╚╚╚╚╚╚╚═
▒ : Wall
═ : Normal track
▲/╚ : N/E Track/Ramp
}}

If a cart enters from the left, it will speed up on every track/ramp and exit to the right going very very fast - more than one tile every step. If it enters from the right then it will bounce back impulsed by the ramp if it's going slow enough.

As another oddity, carts coming from ramps will in some cases "teleport" through most of the next tile. This can be used to send carts up levels with minimal loss of speed. You can just make an upward spiral alternating impulse ramps and regular upward ramps. It takes no power, is quick and cheap to build, requiring only channeling and track carving, and the cart goes up fast, but not so fast that it launches its contents.

Example of an impulse elevator:

{{diagram|spaces=yes|\
z +0 z +1 z +2 z +3
░░░░░ ░░░░░ ░░░░░ ░░░░░
░╔░░░ ░▼╚╗░ ░░▼▼░ ░░░░░
░╝░░░ ░▼░░░ ░░░╔░ ░░░▼░
░▼▼░░ ░░░░░ ░░░╝░ ░╚╗▼░
░░░░░ ░░░░░ ░░░░░ ░░░░░

░ : Wall
╔,╚,╗,╝ : Track/Ramp
▼ : Down Ramp (empty space)
}}

Note that this impulse elevator, due to the checkpoint effect and upward ramp curve effect, will not actually result in carts traveling straight up the ramp. They will lose speed, bounce off a ramp, then be accelerated back into the spiral after a 9-turn delay on both tiles on the floor where they are stopped. This is because the checkpoint effect allows carts to travel up the ramps in a single turn, but also prevents the impulse ramps from adding acceleration unless the cart is slowed to staying on the ramp for more than one turn. Initial acceleration will carry the cart up a variable number of floors before this effect occurs, but this bouncing back and forth will occur every 5z-levels after the first time the cart stops. When the cart ''is'' traveling upwards, it will pass every tile at a rate of one tile per turn regardless of its actual speed, due to the checkpoint effect. In tracks with only a single cart, this is negligible, but when multiple carts are on the same track (such as when you place multiple carts on a magma cart lift) this can cause collisions which derail carts or cause other unexpected or undesired behaviors.

A sort of opposite effect to impulse ramps also exists: ramps lacking the proper "up" and "down" connections are treated as flat track, even if they actually go up or down z-levels. This allows building "anti-impulse" slopes consisting entirely of ramps only connected up, which a minecart can travel up forty levels and more, needing no more than a single push.

=== Controlling traffic ===

==== Switching ====

As constructions or tile features, [[door]]s and other furniture can be built on tracks. A [[door]] or [[floodgate]] can be turned on or off by a [[lever]], effectively controlling the flow of automated minecarts. This may be <s>dangerous</s> [[fun]], however.
{{diagram|spaces=yes|\
->
A ════┤≡════ B
┤ : roller pushing to East
≡ : door
}}
The roller pushes the cart east, but until the "departure condition" is fulfilled, the door remains closed and blocks the path.

[[Bridge]]s can also act as tracks, but only if they're lowered or not retracted. This property can enable levers to turn tracks on and off. However, care should be taken to ensure that such bridges are never operated while a cart is on top of them, as the cart will be flung off the track. It's worth noting that it's often faster, and cheaper, to construct large bridges than long sections of constructed track.

A powered track switch can be constructed by building an "inverted" corner as illustrated below.
{{diagram|spaces=yes|\
B B
║ -> ║
║ ║
════╚═══ ════├════
A C A C
├ : roller pushing to West.
}}

If the cart is pushed East from the stop at 'A' while the roller is activated, it will arrive at 'B'. If the roller is not running, it will arrive at 'C'. The switch works by the roller first reversing the incoming cart's movement and the cart ''then'' following the track corner.

This switch is very reliable, reacts instantly to on/off signals, and carts of any speed can be switched by this design, although very fast carts will require rollers that are several tiles long, up to three. The requirement for power can be inconvenient or impractical. Non-powered solutions may use controlled derailment, or a connecting bridge.
{{diagram|spaces=yes|\
B ╥
║
║
╞════╝ ════╡
A D C
}}
Here the track between A and C is not continuous. The only continuous track is A->B, with a corner (not a T section). Fast moving carts will tend to derail at D and rejoin the track to C. Placing a door at D will prevent the derailment, so the cart continues to B. The door is operated by mechanisms elsewhere (typically, a lever, but some fun can be had with pressure plates).

Since it depends on derailing, this switch requires a very fast cart, faster than what can be achieved with rollers alone. To gain sufficient speed, a cart must be accelerated further, usually by descending several levels or through impulse ramps. The high speed makes the cart much more dangerous and harder to control.

If carts are moving too slowly to derail at the corner, a retractable bridge may be used as a connector between A and C.
{{diagram|spaces=yes|\
B╥
║
║
A╞════bbb════╡C
}}
The bridge must overlap the corner. Bridges behave like a track crossing, allowing carts to pass in a straight line. When retracted, the corner reappears, so the carts will continue to B. Bridges take 100 steps to react to a signal, necessitating rather long "lead times" when switching tracks via bridge.

As mentioned above, special care must be taken to make sure the bridge doesn't change state while the cart is passing over it. Retracting bridges will throw the cart, causing it to stop dead. Raising bridges can even crush the cart.

==== Controlling Speed ====


Minecarts can reach extremely high speeds, especially when descending multiple Z-levels. A minecart will derail at a track corner if its speed exceeds 0.5 t/st (tiles per step), '''unless''' the route in the direction of travel is blocked:

Will derail at > 0.5 t/st:

{{diagram|spaces=yes|\
in ══╗ -> derailing
║
out
}}

Will not derail at > 0.5 t/st:
{{diagram|spaces=yes|\
in ══╗O
║
out

O : wall/column.
}}

This behavior can be used to build a "speed limiter", that will ensure that when a minecart exits it is traveling below derail speed:
{{diagram|spaces=yes|\
░░░░ ░░░░░ ░░░░░
in ═╔═╗░ ░╔S╗░ ░╔S╗░
out ═╬═╝░ out ═╗═╝░ out ═╗═╝░
░╚S╝░ ░╚═╝═ in ░╚S╝░
░░░░░ ░░░░ ║░░░
in
░ : wall
S : Track Stop (High Friction or lower)
}}
If the minecart is traveling below derailment speed, it will not be affected; if above, will be slowed down and checked again. Granted, you could do the same just with track turns, but it may take a lot of turns and time.

Since all the derailings, bounces and ramps can impart a sideway component of speed small enough to start visible drift many tiles away (say, [[Fun|in the middle of a bridge]]), track turns have one more use: forcing the carts to move strictly along the grid directions. Carts passing a turn below derailing speed convert one component of velocity into another, thus eliminating the drift.

=== Loading liquids ===
[[Water]] and [[magma]] can also be loaded into minecarts by submerging them to a depth of at least 6/7 while standing still or moving at speeds of at most 10000. Loading fluids onto minecarts can be difficult because the added friction provided by fluids can stop a cart in a submerged tile. Curiously, filling a minecart with magma does not injure a dwarf ''riding'' it. A minecart will hold enough fluid to increase the depth of a single tile by 2. This amount is listed as 833 units, which weigh 459Γ (water) or 999Γ (magma). An iron or steel cart filled with magma weighs 1313Γ, while an adamantine cart filled with magma weighs 1007Γ. Since you need a minecart above the liquid's level, possible arrangements may include pressure-activated sluices, rollers (with magma-safe chains for magma), pouring from above to "submerge" it briefly on the same level and drain excess away (dig deeper and leave a vaporizer, though if you could have power for rollers, may as well use a pump) and exploits with ramps (not necessarily impulse ramps, "same height" passing dip does it).
The liquids can be dumped by a constructed track stop.

== Quirks ==
This little quirk concerns dwarf-managed minecarts. If a track which was previously open becomes blocked (ex. flipping a switch connected to a floodgate you've built on the track to raise it) and the conditions for departure are met, instead of refusing to ride/guide the minecart or ride/guide it until it reaches the obstacle, the dwarf will pick up the minecart off the tracks and haul it to its scheduled destination on foot. If the distance is long enough and the weight of the cart heavy enough (due to being filled with heavy items such as stones), the dwarf may drop the cart because of fatigue/hunger/thirst before reaching the destination. This will cancel that vehicle setting job and make another dwarf come by and attempt to haul the cart to the nearest appropriate stockpile where another dwarf will pick up the cart and attempt to haul it to its initial stop. If the stockpile is far enough from initial stop, this second dwarf who is attempting to place the minecart on its tracks may also drop the minecart out of fatigue/hunger/thirst creating a loop that will go on until a dwarf with enough endurance manages to place the minecart where it belongs.

In fact, it seems dwarves are more than happy to attempt to carry a minecart from one stop to another even if just waiting until the track is open again would be the more sane option.

Dwarves will also carry a minecart to its next stop if the direction specified is incorrect (or invalid). This can often occur when using the default departure settings and forgetting to set the direction of each condition.

Dwarves can admire buildings while riding mine carts. Dwarves will not fall asleep during a ride (at least not from being drowsy). If riding on a continuous powered track loop, the dwarf will die of dehydration/starvation as they can not jump off to get sustenance{{cite forum|109460/3377228}}. Dwarves riding in submerged minecarts will gain experience in [[swimming]].{{cite forum|129889}}

Tracks block wagon access to trade depots, unless they're on a ramp. [[Bridge]]s can also be used, as they function as tracks but do not block wagons.

== Physics ==


Minecart physics depend greatly on the departure mode set in the route stop conditions.

When set to "Push" or "Ride", minecarts will move according to the regular laws of momentum, gaining speed when going downhill, losing it slowly due to friction when on a flat plane, and more quickly when going uphill. In these modes, minecarts will move in a straight line until they either are brought to a stop by friction or an obstacle, or until they encounter a turn. A minecart will roll straight past "blocked" ends of T-junctions or track ends, they have no power to restrict a cart's movement. The cart's behavior is largely independent of the weight of its contents (including fluids and dwarves): heavily loaded carts gain more momentum when accelerating, but this only plays a role in collisions: a heavy cart gains just as much speed and is as easy to stop as a light one. In either case, dwarves can not push nor ride an unpowered cart up a ramp, bouncing back the direction it came. At best, this is a waste of time; at worst, it will give your cart-pushing dwarf a [[fun|fun surprise]]. To solve this, the player can either use Rollers (see below) or set the cart to be Guided.

The difference between "Push" and "Ride" is whether the dwarf will go along with the cart or not.
{{DFtext|Push}}: the dwarf will give the cart an initial push, not enough to go up a ramp, but enough to go some way along flat track, and the dwarf will remain at the first stop, ready for a new job.
{{DFtext|Ride}}: the dwarf will give the cart the same initial push and then hop aboard the cart riding with it to the next stop.
{{DFtext|Guide}}: minecarts seem to ignore all laws of physics. That is:
*Ignore the weight of any and all items inside. Therefore:
**Move at the speed of the dwarf that is guiding them. It is thus recommended to pick the most [[attribute#Agility|agile]] of your dwarves for cart-guiding tasks.
*Ignore working rollers.
*Will ''not'' collide with other guided carts even when a full frontal collision would be expected.
*Will go up ramps like nobody's business.
This is therefore the recommended method of transport for simple non-powered rail systems, despite it diverting a dwarf from other, potentially more important tasks.

Some samples with behavior:
{{diagram|spaces=yes|\
A <-> B A <-> C A <-> B
B B B
║ ║ ║
A══╝ A══╩══C A══╬╗
You can only go A->B ╚╝
Works when the cart Works
is in Guide mode.
}}
In the second example above, a cart "pushed" from B will go over the junction and roll off into the unknown south.

=== Track Direction Irrelevance ===
Carts that are traveling independently, (that is, not guided,) only care that tracks ''are'' on the tile, not which direction the tracks actually move. Tracks respect only curves (with two exits) and ramps.

This means, for example, that the following tracks, when a (non-guided) cart travels from West-to-East, are functionally identical in effect:

A════════════B A╬║╚╔╣╩╦╠╥╨╞╡B

This is because so far as the cart is concerned, only ramps and curves with two exits where the exit in the path they are traveling matters.

Carts only check for curves when they are halfway through a tile. When they get there, they look to see if their path has no exit. (That is, if it is traveling East, it checks if there is an East exit.) If there is, it ignores all other track directions, and keeps traveling. If there is not, it checks to see if there are only two exits to the track, and if one of those directions was the direction it "came from". (That is, if traveling from the East, it checks if there is a valid exit to the West, and if so, if there is either a North exit or a South exit.) If there is not, it ignores the track anyway, and keeps on traveling as though it were still on track. If there is, it will subtract 1000 from the velocity of the cart, and redirect all forward velocity to the direction of the curve. This change in the direction of velocity ''overwrites'' any "diagonal" velocity, which can prevent diagonal velocity derailments, but any perpendicular velocity is not preserved, and is instead discarded.

=== Invalid Ramps ===
Ramps are functionally defined for cart purposes as being a tile which exerts an acceleration force upon its "downward slope". This downward slope requires a cart to have one ''and exactly one'' carved exit to the tile that is the "bottom" of the ramp. Ramps push carts in this "downward" direction (possibly leading to diagonal movement, below), and the deceleration of an "uphill" ramp is actually just the acceleration being applied against the direction of a cart's movement.

This is where players can find an exploit in the behavior of ramps - if there are ''two'' "downhill" exits to a ramp (such as a "T junction" on a ramp where only one exit faces a wall), then the ramp provides no acceleration ''or'' deceleration, allowing carts to travel up ramps without any loss of momentum except for the standard "flat track" deceleration, because as far as the cart is concerned, the track ''is'' flat.

Similar effects can be achieved when there are ''no'' "downhill" exits to a ramp. This may be the case if you have, for example, an East-West track with a one-tile channel with a ramp in it. The cart will travel through the "dip" with no change in velocity. It can also be the case if you abuse the Track Direction Irrelevance, above, and set only exits ''up'' the ramp, and none leading ''down'' the ramp. For example, if a cart is traveling from West to East up a slope, only carving East exits on each tile of ramp will make the cart travel up the ramp, and then recognize the tile it is on as being a "flat" tile, thus ignoring any deceleration from traveling uphill. Note that this effect only reliably occurs at relatively slow speeds (at around push, or single accelerating ramp speeds) as the cart may simply ignore the ramp and crash into the wall at higher speeds.

=== Skipping ===
If a minecart is moving fast enough, it can skip over [[water]] or [[magma]], making splashes of [[mist]] (or [[magma mist]]) as it attempts to move on them horizontally. This horizontal movement is independent of the minecart and its content's [[weight]].

=== Track Jumping ===
If a minecart encounters the end of the track or a T junction with no "exit" in its movement direction, it will simply leave the track and continue on its course in a straight line until it encounters an obstacle, slows to a stop, or encounters another (properly aligned) Track even if the tile at which it joins the new track instantly sends it around a corner.

Tracks that are travelling at high enough velocity will also start "jumping" the track if it hits an un-tracked tile (flying over and ignoring any tracks) until it is ready to land. Carts that land upon tracked tiles re-rail themselves, and clever designers use this feature to jump over curved track sections in one direction or another. (Retracting bridges over untracked tiles can cause jumps or not cause jumps depending upon the status of the bridge.) Minecart speed must be carefully regulated to ensure reliability of jump length.

Carts that approach a downward slope at a high enough velocity will also make a jump, but will not do so if the Checkpoint Effect (below) is exploited through an impulse ramp before the actual downhill as the impulse ramp "tricks" the cart into thinking it has already started going downhill.

=== Corner Ramp Derail ===

Corners on upward ramps can cause diagonal movement, forcing a derail even if the cart has a wall next to it, which will force a stop when it touches a wall that forces dwarves to manually reset the cart.

This is caused by the fact that a cart, after turning the bend in the track halfway through the length of the tile, will still "accelerate down", which is now perpendicular to the movement of the cart, causing acceleration to occur in two directions. (Down corner ramps do not have this problem, as when they pass the halfway point, all perpendicular motion is added to forward motion, and after that curve, all downward acceleration is in the forward direction.)

There are two fixes to this problem. One is to simply not put corners on up ramps. The other is to take advantage of the Checkpoint Effect, below, by making a ramp (possibly including an impulse ramp) one tile in front of the ramp to make it skip through most of the tile before sideways momentum can be built.

=== Checkpoint Effect ===
The checkpoint effect, [http://www.bay12forums.com/smf/index.php?topic=144328.0 explained in depth by Larix], is an odd and highly exploitable feature of ramps where minecarts "teleport" through the next tile of track, ignoring nearly all minecart physics (except that they stop at all walls or other obstacles and not only respect curves, but will take them even when they would otherwise derail) and passing through that tile in just a single tick, and into the next tile at the halfway point.

This effect occurs when a cart leaves a downward ramp for any other direction of tile. (This includes ramps which accelerate in different directions, even a ramp which goes from accelerating East to accelerating North due to a bend in a chain of standard down ramps in a curve.) This allows, for example, two valid straight ramps directly next to one another with a cart dropped onto one or the other with no momentum to have the cart pick up acceleration going "down" the ramp as normal, but then flying up through the "up" ramp it travels into with no loss of momentum, as though it had come from an impulse ramp. If the two ramps had at least one space of distance between them, and then a cart were dropped in, the cart would instead "rock" back and forth between the two ramps.

This seems to be because ramps have a slightly longer length than regular tiles - 144,000, rather than 100,000 distance. When this "snaps back" after a ramp, it seems to project the cart suddenly further along the track, making it jump a tile ahead even when otherwise moving at relatively low speeds.

This [[bug]] is the cause of a ''wide array'' of unexpected behavior among people who do not take this bug into account. It causes derailments or failure to climb up seemingly valid impulse elevators. In general, it makes a system that behaves extremely counter-intuitively, and operates ''any time a cart encounters a valid ramp''. At the same time, when its effect is accounted for, it is highly exploitable: It causes "perpetual motion devices" using no power when two opposing ramps are placed next to one another, since the "uphill" effect of the opposing ramp is ignored, preventing deceleration.

Another useful thing to note about this exploit is that carts traveling at no less than 72,000 or so speed (enough to travel half a ramp tile in a single tick) can travel through every tile in just one tick at no change in velocity as long as the tiles alternate between impulse ramp or actual down ramp and any other tile type. The cart checkpoints through the non-down-ramp tiles, and can pass through the (impulse) down ramp tiles in a single tick, before they can actually start gaining momentum.

=== Falling ===
When falling, a minecart appears to cause no damage upon collision, possibly to allow cart "stacking" across Z-levels.{{cite devlog|2012|04|06}} A dwarf riding in a minecart that is dropped multiple z-levels suffers normal fall damage. Minecarts can fall through up/down stairs.
The cart falling (from a hatch, thus with no horizontal speed) onto a track ramp is accelerated as if starting from the middle of the ramp - i.e. to the same speed, no matter how many Z-levels it was dropped, vertical velocity is negated. {{cite forum|144328/5701211}}

=== Stacking ===
If a minecart lands on top of another minecart, they may form a stack, with the upper cart on the z-level above the lower. Subsequent carts do not form a stack, but rather quantum stockpile in the same space. This behaviour is useful for [[megaprojects]] and [[trap design]] with minecarts as the weaponry. Moderation should still be exercised: carts take longer to fall into a "stacking" tile already occupied by other carts and will spend that time "hanging" in the air above the stack. This can lead to following carts striking them, which can cause all kinds of malfunctions. The extra time is two game steps for every cart already in the stack, which doesn't hurt stacks of ten carts very much but makes stacks of 100+ rather impractical.

These minecarts on the upper level generally need to be struck with another minecart to move out, or have their support removed. The latter option is safest done by shooting it away with another minecart, manual removal of a stack-supporting cart typically causes the next cart from the stack to [[fun|fall on top]] of the hauler.

=== Perfectly Elastic Collisions ===
Minecart collisions are perfectly elastic, meaning that not only do minecarts not take damage, but that two carts that are rolling which have frontal collisions of near-similar speed, and where one cart is no more than twice the mass of the other cart, will result in a billiard-ball-like effect of the lighter cart bouncing off the heavier cart with a proportional speed increase dependent upon the relative momentum behind the heavier cart.

Using this trick with carts already at the 270,000 maximum speed from ramps can result in "supersonic" carts traveling at speeds in the millions (travelling a dozen tiles per tick), but where they are suddenly subject to 10,000 units of "terminal velocity" friction per tick. [http://www.bay12forums.com/smf/index.php?topic=137557.0 Thread with SCIENCE here].

While hypothetically capable of launching a minecart into orbit when used in conjunction with a ramp, no cargo can be contained in the launched cart, as the collisions will force ejections of the cargo. Your "unwilling volunteer" [[goblin]] space pioneers will simply become paste underneath the wheels of an extreme high-speed cart.

=== Numbers behind the scene ===

According to early research by '''expwnent'''{{cite forum|112831/3536975}}:

The minecart has a variable for speed. Speed is measured in tiles/100000 ticks, so a speed of one hundred thousand means one tile per tick. By going down a large number of ramps, a maximum speed of 270,000 can be reached, which presents the limit for most practical applications. Short bursts of (much) higher speeds are possible through carefully planned collisions of high-speed carts {{cite forum|137557/5145499}}.

Every tick the cart accumulates distance units, as well as slows down depending on current tile (speed is reduced by "friction" of the tile). The cart will move to the next tile the tick before accumulating 100000 distance units, (or several tiles in case of great speed), then the leftover distance units are added to the default 100000 distance u. of the next tile. Since most deceleration and acceleration is applied per step, with the notable exception of corners, a cart going at twice the speed of another one can cover about four times the distance in a straight line, but only twice the distance along a winding track with very many corners.

A push will teleport a cart to the beginning of the next tile (NOT the middle!) in one tick with 19990 speed (10 speed is lost due to track friction), while a roller will give a cart the roller's set speed, and it will start to accumulate regular track friction past the middle of the roller tile. Some track features will affect a minecart when it is past the middle of the previous tile: entering a ramp or a hole/drop will happen when the cart has left the middle of the previous tile, and the ramp will gain additional distance unit depending on the leftover units from the previous tile. When a cart leaves a ramp it will emerge after one tick in the middle of the next regular tile, so its entry coordinate is "50000-speed+friction". Rollers also affect the speed of minecart from the middle of the previous tile.

Friction of tiles:
{| class="wikitable"
|-
! Tile
! Friction
! Comment
|-
| Tracks
| 10
|-
| Ground/Floor
| 200
|-
| Unusable ramp
| 10
|-
| Upwards ramp
| 4910 (10+4900)
|-
| Downwards ramp
| -4890 (10-4900)
|-
| Roller
| ±100000 (but capped by the set speed)
|-
| Corner track
| 10
| Speed reduced by 1000 upon leaving the corner tile
|-
| Track stop (highest)
| 50000
|-
| Track stop (high)
| 10000
|-
| Track stop (medium)
| 500
|-
| Track stop (low)
| 50
|-
| Track stop (lowest)
| 10
|-
| Water 1-6
| Additional (WaterLevel - 1) * 100
| rowspan="2" | [[#Skipping|See Skipping]]
|-
| Magma 1-6
| Additional (WaterLevel - 1) * 500
|-
| Empty space
| 0
|}

Water of depth 7/7 provides a friction of about 10000 per step, as does maximum-depth magma. This higher friction may not apply to very slow-moving carts.

Impulse sources:
{| class="wikitable"
|-
! Feature
! Speed
|-
| Push
| 20000
|-
| Roller lowest
| 10000
|-
| Roller low
| 20000
|-
| Roller medium
| 30000
|-
| Roller high
| 40000
|-
| Roller Highest
| 50000
|-
|}

== Non-standard uses ==
Minecarts include some interesting characteristics that have motivated uses beyond hauling. They can be useful for creating fully-automated [[exploit|quantum stockpiles]] and [[garbage disposal]]s. Storing perishable goods (meat, meals, etc.) inside a minecart appears to guard against rot and vermin.
Minecarts can be [[Trap_design#Minecarts|used as weapons]], or as (hopefully non-fatal) triggers to restart stalled [[healthcare]]. They can also be used to time/control game events, either using a basic [[repeater]] or much more advanced [[minecart logic]].
Minecarts trigger [[pressure plate]]s, which means a trap can be designed to trigger when a thief attempts to steal a minecart.
A pressure plate can be used as automatic and more precise custom "launch when full enough" system - as long as weight of your minecarts stays the same. You cannot build a hatch or roller on the same tile, so launch by bumping with another cart. {{cite forum|15096/4580050}}
Dwarves riding minecarts can attack enemies within reach (which goes back to dev log). This applies to shooting, and they actually can hit targets while riding by.{{cite forum|109460/5266119}} Whether a minecart protects the rider and how it interacts with dodging is not known yet. Minecart riders can also [[Swimming#Minecart_training|train swimming]] and [[Megaprojects#Surveillance_Track|detect ambushers]].

== Adventure mode ==
In addition to being used for hauling, minecarts can also be ridden in [[adventure mode]]. (Adapted from forum thread {{cite forum|122903/4258212}})

# If the minecart is in your inventory, drop it. If it is already on the ground, proceed to step 2.
# Press {{k|u}} when you are 1 tile away from the minecart (or standing on the same tile as the minecart).
# You will be presented with the following options:
[[File:minecart adventure mode menu.png|left]]
{{clear}}
* If you {{DFtext|Push}} the minecart, it will move a few tiles in the direction you chose. Physics comes into play here, so it will gain/lose speed depending on the usual factors.
* If you {{DFtext|Ride}} the minecart, you will hop into the minecart, even if you were a tile away, and it will move in the chosen direction with you in it. It will gain/lose speed depending on the usual factors. Whilst the minecart is in motion, you should press {{k|.}} to skip your turn; if you attempt to move whilst the minecart is still in motion, the laws of physics come into play, and you will take [[wound|damage]]. Alternatively, you can push the minecart whilst it's still in motion (although it's unclear how one can bend [[physics]] so as to push a moving minecart whilst inside the minecart). If you push it in the same direction you are already travelling in, you will greatly increase the minecart's velocity. You can also push it in different directions, and this will cause it to gradually change direction-the amount of pushes this requires depends on the minecart's velocity. Once the minecart has stopped moving, you may move out of it safely, or you may want to give it another push. Note that if you push a minecart right after having ridden it (still on the same tile as the minecart), it will act as though you chose to ''ride'' it.

If you want to test this out without creating an adventurer, the [[object testing arena]] allows you to spawn minecarts ({{k|k}}-{{k|c}}-{{k|n}})

== Forging and Melting ==
* Metal minecarts cost '''two''' [[metal]] bars to forge, or '''six''' [[adamantine]] wafers.
* When a non-adamantine metal minecart is melted down, it will return '''1.8''' metal bars, for an '''efficiency of 90%'''.
* When an adamantine minecart is melted down, it will produce '''1.8''' wafers, for an '''efficiency of 30%'''.

== See also ==
* [http://www.bay12forums.com/smf/index.php?topic=109460.0 The "How Does Minecart" Thread] by '''Girlinhat''' et al.
* [http://www.bay12forums.com/smf/index.php?topic=112831.0 SCIENCE: Quantifying minecart physics] by '''Snaake''' et al.
* [http://www.bay12forums.com/smf/index.php?topic=129676.0 How to build a Multi-cart Ore to Magma Minecart Project without needing power] by '''WanderingKid'''.
* [http://www.bay12forums.com/smf/index.php?topic=144328.0 My very own Minecart Education Thread. Ten Lessons, now complete.] by '''Larix'''.

== Bugs ==
*A dwarf will drop her [[child|baby]], if she has one, when boarding a minecart set to be ridden.
*Dwarves have no concept of traffic safety and will walk into busy minecart lines to retrieve objects, often with deadly consequences. This is especially problematic in [[Swimming#Minecart_training|clever applications]] depending on dwarves riding the carts very frequently, because they have a bad habit of dumping their worn clothes on the tracks after a minecart ride. Adding an automatically-operated [[hatch cover]] at the end of such a ride can help prevent [[unfortunate accident]]s.
*Dwarves cannot guide a minecart through an unlocked door unless another dwarf opens the door.{{bug|6056}}
*It is possible for a creature and minecart moving towards each other to pass without collision if they exchange tiles in the same tick.
*After a minecart ride, a dwarf will sometimes haul the minecart to a storage stockpile, leaving another dwarf to haul the vehicle back to the route.
*Minecarts falling onto a floor injure creatures in the tile below the floor.{{bug|6068}}
*A minecart's initial velocity is not affected by weight, when pushed or launched from rollers.{{bug|6296}}
*Removing a stop that has a vehicle waiting on it may cause the game to crash.{{bug|5980}}

{{Category|Fortress mode}}
{{Category|Interface}}

[[ru:Minecart]]

Minecart

2015-06-18T02:49:43Z

NW Kohaku: /* Impulse ramps */

{{Quality|Masterwork|08:15, 19 May 2015 (UTC)}}
{{av}}
A '''minecart''' is a [[tool]] intended for [[hauling]], introduced in version 0.34.08. It can be made of [[wood]] at a [[carpenter's workshop]] or [[metal]] at a [[metalsmith's forge]] (using the [[Metal crafter|metalcrafting]] labor.) Minecarts store up to five times as many items as [[wheelbarrow]]s and are quite a bit faster than dwarves hauling objects by hand, but have the disadvantages of requiring a dedicated track network, a complex route planning phase, and the possibility of dwarves [[Fun|blundering into the path of carts filled with lead ore]]. Tracks may be carved into stone, or [[Construction|constructed]]; the latter allows above-ground routes, but these are more difficult to set up due to their additional [[building material|material requirements]].

Just like wheelbarrows, minecarts are considered [[item]]s and are stored in a [[furniture]] [[stockpile]]. Despite their five-times-greater capacity, they are only 33% larger than wheelbarrows and are identical in base [[item value|value]] when made from the same [[material]] (the value may differ due to the [[item quality]]). [[thief|Thieves]] or even mischievous animals can steal minecarts, even when they are moving on a track{{cite forum|109460/3289070}}. However, minecarts moving fast enough or being ridden cannot be stolen.

Although most of the utility of minecarts is in [[fortress mode]], an [[adventure mode|adventurer]] can also ride in a minecart. Adventurers can also pick up and relocate minecarts.

The invention of minecarts revolutionized the [[minecart logic|Science of Dwarfputing]] by enabling smaller, faster logic systems to be built.

== Basic Minecart Usage ==
Minecarts can be used to swiftly transport dwarves, [[flow|fluids]], and/or large amounts of items, but before you have a functional minecart there are several preconditions that need to be met. First of all you need an actual minecart, constructed either in a [[carpenter's workshop]] or [[metalsmith's forge]]. For the minecart to be able to move you also need to carve (with {{k|d}} {{k|T}}) or construct (with {{k|b}} {{k|C}} {{k|T}}) a track, which could be as simple as a straight line. Finally you need to construct stops on your track (with {{k|b}} {{k|C}} {{k|S}}) where the minecart will start and stop.

After you have created the stops and assigned a cart to the track, you must create logic routes connecting several stops and designate starting conditions for each stop. This is done with the {{k|h}}auling key. The most basic conditions are how the cart's movement is initiated and in which direction the cart should start moving. Carts can be either be Pushed (a dwarf stands at a stop and gives the cart a single push) or Guided (a dwarf continually pushes the cart forward, guiding it along the track). The [[hauling]] [[labor]] required for pushing and guiding carts is called "Push/Haul Vehicles" and is turned on by default.

To control which items to transport you can add conditions specifying: (1) which kind of items to be loaded, and unloaded, (2) stockpile links to define which stockpile(s) the items should be un/loaded to and from.

===Capacity and weights ===
Minecarts have five times the [[Weight|capacity]] of [[wheelbarrow]]s.

'''Examples of the capacity of one cart'''
{| class="wikitable"
|-
! Item
! Amount
|-
| [[stone]]
| 5
|-
| [[wood|log]]
| 10
|-
| [[block]]/[[bar]]
| 83
|-
| [[Kitchen|prepared meals]]
| 500
|-
| [[Trap_component#Spiked_ball|spiked balls]]
| 500
|-
| [[Weapon#Native_weapons|mace]]
| 625
|-
| [[Weapon#Native_weapons|spears]]
| 1250
|-
| [[cloth]]
| 2500
|}

The weight of the loaded minecart does not affect the initial velocity received from pushing or launching from a roller. However, the load of a minecart ''does'' affect whether a [[pressure plate]] triggers or not, based on the pressure plate's setting.

'''Weights of different carts'''

{| class="wikitable"
|-
! Type of cart
! Empty cart
! Fully loaded (items)
|-
| oaken minecart
| 28Γ
| 378Γ (10 oak logs)
|-
| platinum minecart
| 856Γ
| 10482Γ (83 gold bars)
|}

The weight of a minecart is one twenty-fifth (1/25) the [[density]] of its material in Urists. Because pressure plates can be set to trigger at intervals of 50 Urists, minecarts with weights just under a multiple of 50 are ideal for switching based on whether they're full or empty. The best minecart materials for full/empty switching are as follows:

{| class="wikitable sortable"
|-
! Material !! Minecart weight !! Content weight required to trigger !! Banana roasts required to trigger (for scale)
|-
| [[Bismuth]] (moods only) || 391 || 9 || 15
|-
| [[Brass]] || 342 || 8 || 14
|-
| [[Electrum]] || 596 || 4 || 7
|-
| [[Fine pewter]] || 291 || 9 || 15
|-
| [[Glumprong]] || 48 || 2 || 4
|-
| [[Lay pewter]] || 291 || 9 || 15
|-
| [[Nickel silver]] || 346 || 4 || 7
|-
| [[Tin]] || 291 || 9 || 15
|-
| [[Trifle pewter]] || 291 || 9 || 15
|}

=== Creating tracks ===
Minecart tracks are made up of contiguous track, tracked ramp, or bridge tiles. Track tiles and tracked ramp tiles have a direction or series of directions associated with them. These directions dictate which directions a minecart on a given tile may move from that tile. For example, a Track NE (northeast) tile allows a minecart on it to move either north or east from its present position. Therefore, if you want your minecart to move east along a straight piece of track, then return west using that same track, you would need to use EW tracks so that the cart could travel east initially, then return west over the same track. Excluding designs in which the cart will "jump" tracks via a drop or other ramp, tracks must be valid end to end to work for most looped or straight-track applications. A single east only track tile in your line of east-west tracks will cause any route using the track to fail the moment it tries to go the wrong way over that tile. Minecart tracks can be built in two ways: Engraved/carved or constructed. A given minecart track need not use engraved or constructed elements exclusively, as the two methods can be used interchangeably depending on the needs of a given section of track. The way the tracks are built is slightly different between the two, as explained below.

====Simple tracks====

'''Carved'''

A single-tile wide strip of natural stone can be designated to be [[Engraver|carved]] (with {{K|d}} {{k|T}}), which will create a straight two-way track. The creation of corners, crossings, and T-junctions is as simple as designating another strip of track that overlaps an existent or newly designated track. Engraved tracks are removed by [[smoothing]] the rock they're on, which results in a smooth floor (that can be re-engraved if necessary), or by building a [[floor]] on top and subsequently removing it. Dwarves can carve corner tracks in one pass by designating the track carving twice and canceling unwanted carvings (with {{K|d}} {{K|x}}). Tracks can be engraved in any natural floor tile, rough, smooth and even over engravings, providing an easy method to remove low-quality or undesired floor engravings. Once a track has been engraved, it's important to check the track directions for each tile in the route carefully to make sure no mistakes were made by yourself or the game's track engraving logic.

'''Constructed'''

Tracks can also be built as regular [[construction]]s (through {{K|b}} {{K|C}} {{K|T}}). This method is resource-expensive, since each track tile requires one stone, [[bar]], or [[block]] for construction, and time-consuming, since you can't designate strips longer than 10 tiles at a time. Corners, crossings, T-junctions, and ramps also have to be designated individually. However, it is usually the only way to build tracks above ground or on soil (barring the [[Obsidian farming|creation of obsidian]]). Constructed tracks are designated for removal like any regular construction; be aware that removing track ramps built on top of natural ones will also remove the original ramp, leaving a flat floor.

====Ramps====

'''Carved'''

The carving of natural ramps is a little more confusing: to carve a two-way track on a ramp (natural only, does not work on constructed ramps), you must designate the track '''starting on the ramp and one square beyond''' in the direction you want the track to go. For the side of the ramp square you want to head upward, there '''must''' be either a natural or constructed wall in the square next to it, otherwise the game assumes you are trying to carve it on the same level -- this can result in the track being carved underneath a door or other object. If you have accidentally done this, you can correct it by smoothing the ramp and constructing a single square of wall next to it, then re-carving the ramp correctly. (However, the wall must stay there permanently; removing it will disconnect the track.)

'''Constructed'''

When constructing track ramps, the stated direction should be the same as the connected tracks. For example, a track going up from West to East would require, starting from the West, a Track (EW), a Track/Ramp (EW) and a Wall behind the ramp, underneath the section of track above it. Incorrectly placed ramps result in minecarts ignoring the ramp and crashing into the supporting wall. They will not, however, display as unusable as when the supporting wall is missing.

'''Examples of ramps'''

A simple ramp would look like this:
{{diagram|spaces=yes|\
z +0 z +1
░░░░ ░░░░
═▲o ░▼═
░░░░ ░░░░
o : wall
}}

Carving track corners into ramps is rather unintuitive and complicated. Since engraving tracks always requires two tiles to connect in a straight line as input, you have to give two separate designations for a single job: a track bit from the ramp tile to the "below" direction and another one to the wall of the "upward" direction. If you wanted to change direction on a ramp from east to north:
{{diagram|spaces=yes|\
z +0 z +1
░░░░░ ░░░░░
░░░░░ ══╗░░
=▲░░ ░░▼░░
░░░░░ ░░░░░
}}
you would need to connect the ramp on z +0 both to the west and to the north by issuing two "carve track" commands, one selecting the ramp and the track tile to the west, and another connecting the ramp tile with the wall to the north. An engraver would then carve a NW track corner into the ramp, allowing carts to pass the corner correctly both going up and down. Such track corners are perfectly serviceable for guided carts, but moving down a route of several of them by pushed or ridden cart is problematic - ramps on corners behave very counter-intuitively, resulting in loss of speed when going down and diagonal movement when going up.

Moving to and from ramps (or between ramps "pointing" in different directions0 causes some non-trivial adjustments to speed and even moving along the tiles at a fixed speed ''unrelated to the entry/exit velocity values'', because transitions to/from ramps are processed differently and are not to be "skipped". This affects compact track/ramp combinations (such as e.g. a simple 2x2 ramp spiral) most, and combined with bouncing often makes them work not in the way one could expect. {{cite forum|144328/5705102}}

{{anchor|Tracks}}

=== Hauling route ===
A hauling route is a list of directions describing how and under what conditions a minecart will move. The proper setting up of routes is essential for a working rail system. Routes, stops, departure conditions and stockpile links are managed from the {{k|h}}auling menu.

==== Route ====
A route defines the path a minecart will take along a track, as well as under what conditions it will move or stop moving. A route is made up of stops. Stops are precisely what they sound like, a position on the track at which you want a minecart to stop. A minecart track might use as little as a single stop for a looped track, which will serve as both a starting and stopping point for the cart, or it could contain many stops, perhaps to load supplies or wait for a bridge to be manually lowered, before reaching its destination or returning to its starting point. It is important to note that you only need to place stops on a route where you actually want the cart to stop and wait for some action to occur. They are not needed to help navigate the cart along the track beyond telling it where on the track to stop.

New routes are created with the {{k|h}}auling key. Existing ones can be removed (without confirmation) with the {{k|x}} key, and also {{k|n}}icknamed. Before operating, the route must have a {{k|v}}ehicle assigned to it (this can be done with either the route or a stop selected). Assigning a full minecart to a route may result in a slow hauling job if the contents are heavy.

==== Stops ====
Stops are the individual waypoints that make up a hauling route. A given stop consists of the location of a tile, as well as conditions describing when, where, and how a cart should be moved after being stopped at that tile. Stops can be created from within the {{k|h}}auling menu, by placing the cursor over a tile and hitting {{k|s}} while highlighting the route (or a stop within) you've already designated. A minecart will begin its route at the first stop created, and continue through each subsequent stop, being guided, pushed, or ridden from each stop to the next depending on the conditions specified. In many basic minecart applications, the cart will end up at the same stop it began at, though this is not always the case. It is important to note that hauling stop order is enforced, even if there is no track. A dwarf will drag the cart overland back to a skipped stop in the route's list if your tracks bypass it somehow.

Once a stop has been placed, it is given a default set of conditions under which to move the minecart if it is stopped there. Each new stop gets the same default conditions regardless of the track it is placed upon (e.g. guide the cart to the north). For this reason new stops might get marked by yellow exclamation marks ({{DFtext|!|#ff0}}) due to invalid directions. One important thing to note is that as you place additional stops, the display will show paths between the stops you have defined. However, this is '''not''' necessarily the actual route the minecart will take once the route is in operation. For example, if a route were defined with two stops at opposite ends of a track with many twists and turns, a line will be drawn directly between those stops to show the order in which they will be visited. These route lines may crisscross all over the tracks, but so long as the track is valid end to end, the cart will follow the track from one stop to the next, even across twists, turns, and z-level changes. Stops, which are the steps that make up a route, should not be confused with Track Stops, described below.

===== Stockpile links =====
By placing the cursor on top of a stockpile and using {{k|s}}, you can create stockpile links while defining a hauling stop. Links can also be redefined by selecting them, placing the cursor over a different stockpile, and pressing {{k|p}}. The cart will then be filled by items present in its various linked stockpiles in preference to other items. Note that bins should be used with caution in stockpiles that are linked to minecarts. Bins cause problems when used with the "Desired Items" list in a stop's conditions. For example, if a minecart is set to accept only granite blocks, and to depart north when it is 100% full of granite blocks, it will not depart if any of those granite blocks are in bins, even if bins are also included in the desired items list. Two solutions to this problem exist as of v0.40.24. First, bins can be disallowed in stockpiles that are linked to stops. Alternatively, bins '''can''' be used in conjunction with minecarts provided that the minecart's departure conditions use only "any items" instead of "desired items." This option can be toggled in the advanced conditions menu for a stop, accessible via the {{key|C|}} key. The cart's contents can still be controlled by specifying what items are allowed in the linked stockpile.

===== Departure condition =====
Departure conditions involve setting conditions in which the minecart will leave on the route. Each condition includes:
# A departure mode (Guide, Ride or Push).
# An initial departure direction (NSEW). Note that this defines the initial direction of movement only. Even if a track includes many turns, as long as the initial movement direction is valid the cart will follow the minecart track thereafter.
# A timer, before which the departure condition cannot be met.
# Conditions on the amount of items in the cart.
Departure conditions are created with the {{k|n}} key. A new departure condition will read: "guide north immediately when empty of desired items". This condition can be changed between basic presets with {{k|c}}. "Advanced" mode ({{k|C}}) allows for more precise control over departure conditions: fine tuning the percentage from 0 to 100 in 25% steps ({{k|f}} and {{k|F}}), switching it being either the maximum or the minimum amount of items for the condition to be met ({{k|m}}), and whether the cart accepts all or only a specific set of items ({{k|l}}). Common to both screens are the departure mode ({{k|p}}, Push, Ride or Guide), {{k|d}}irection, and timer ({{k|t}} and {{k|T}}) options.

To have a cart only carry a specific set of items, the stop can be set to only carry "desired" items, opening the selection screen with the {{k|Enter}} key while having said stop condition selected, and toggling as desired, or it can simply be linked to a stockpile and set to depart once it is full of items from its linked stockpiles, regardless of type.

=== Track Stops ===
A Track Stop, not to be confused with a route stop, is an optional, single-tile construction which serves two purposes. First, it can be used to cancel a cart's momentum in order to slow or stop it as it passes over the Track Stop. This might be necessary if a cart were pushed down a series of ramps to its destination. Second, a Track Stop can cause a cart to automatically dump its contents as it passes over the Track Stop. Track Stops are constructed via {{k|b}} {{k|C}} {{k|S}}, and must be constructed atop an existing piece of track. If a Track Stop has been set to automatically dump a cart's contents, the cart will dump its contents in the direction indicated when it passes over the Track Stop. Depending on the friction settings chosen for the Track Stop, the cart might then stop after dumping, or it might continue on its route to another destination.

Track Stops are not mandatory; in fact, their main use is in automated rail systems. However, even in basic rail systems it can be useful to set a Track Stop to dump items: this saves time that dwarves would otherwise spend in removing items from the cart, time that is better spent driving the cart back to where it's needed. Dumping will occur even with a guided cart. '''Take care not to set Track Stops at a loading site to dump their contents''', or dwarves will never be able to fill the cart. It will dump any contents the moment they are loaded.

Counter-intuitive to their construction method, Track Stops are considered [[building]]s and must be removed by {{k|q}} {{k|x}}.
* See [[#More_on_Track_stop |More on Track Stops]]

=== Step-by-step tutorial ===

Let's construct a simple minecart route. This route will move stone blocks from an input stockpile to an output stockpile. We'll begin by creating the stockpiles:

[[File:minecart-example-1.png|Stockpiles designated.]]

The input stockpile is on the left; the output stockpile is on the right. We'll be moving blocks from left to right. Disable bins in both stockpiles, and set the input stockpile to accept only from links. Then make the stockpile take from the mason's workshop where the blocks are being produced.

Next, carve the track:

[[File:minecart-example-2.png|Track carving designation.]]

Note that the ends of the designation are uniquely shaped; this is automatic, and not anything you need to control. Now, wait for your engravers to come along and carve the track into the stone. (Your haulers will probably also fill up the input stockpile while you wait.)

In addition, while we're waiting for that to happen, we'll build an iron minecart in the forge.

[[File:minecart-example-3.png|Track carved.]]

When the track has been carved, it will look like the above (the track will be solid instead of flashing). Now, order a track stop to be constructed next to the output stockpile:

{|
| [[File:minecart-example-4.png|Track stop designation.]]
| [[File:minecart-example-5.png|Select dumping direction.]]
|}

You must press {{k|d}} three times to select the dumping direction ''before'' placing the track stop. We want our blocks to be dumped into the output stockpile east of the track stop. Then wait for a mechanic to come along and build the track stop.

[[File:minecart-example-6.png|Track stop constructed.]]

Now we'll define the actual ''route''. This is done in the {{k|h}}auling menu. Press {{k|r}} to begin defining a route. Next, move the cursor to the input end of the track, and then press {{k|s}} to define the first stop:

{|
| [[File:minecart-example-7.png|Stop 1 designation.]]
| [[File:minecart-example-8.png|Route definition, in progress.]]
|}

Move the cursor again, to the output end of the track, and press {{k|s}} again to define the second stop:

{|
| [[File:minecart-example-9.png|Stop 2 designation.]]
| [[File:minecart-example-10.png|Route definition, two stops.]]
|-
|
| [[File:minecart-example-11.png|Stops are not defined yet.]]
|}

There are several user interface features to note at this point. The stops have been positioned, but they haven't been ''defined'' yet, so there is a warning {{DFtext|!|#ff0}} symbol by each of them. In the lower right corner, we see what the {{DFtext|!|#ff0}} means. Also, note that the second stop is labeled in white, while the other two lines are grey. The white text is a selection indicator, and can be moved up and down by pressing {{k|+}}/{{k|-}}.

Next we need to define what our stops do. We want the minecart to be filled with blocks at the first stop, then travel to the second stop where it will dump its cargo, and then return. Press {{k|-}} to move the selection up to stop 1, and {{k|Enter}} to open it up. By default, the stop has three conditions:

[[File:minecart-example-12.png|Default stop definition.]]

We don't want any of these, so press {{k|x}} three times to delete them. This leaves us with a blank stop. Now we can add the conditions we actually want. Press {{k|n}} to begin adding the first condition, then {{k|d}} twice to change the direction from north to east. Then press {{k|c}} to change the condition from empty to full. This will instruct the minecart to be guided east when full of desired items.

To set the desired items, we create a stockpile link. Press {{k|s}}, then move the cursor to the input stockpile, then press {{k|p}} to select that stockpile. Now press {{k|Enter}}; this opens up a selection screen that resembles the stockpile customization screen. Move down to Blocks, {{k|e}}nable them, then (if you wish) restrict it to stone blocks.

When you've done all that, stop 1 should look like this:

[[File:minecart-example-13.png|Stop 1, defined.]]

Stop 2 is much simpler. All we need to do is have the minecart return to the input stop. So, make a condition and change the direction:

[[File:minecart-example-14.png|Stop 2, defined.]]

Finally, we just have to assign our minecart. Go back to the route definition screen, and press {{k|v}}. Select the minecart, and press {{k|Enter}}.

Now we've got everything set up:

[[File:minecart-example-15.png|Route, fully defined.]]

The V is red because the minecart hasn't been moved onto the track yet. Some dwarf will have to haul it from the forge to the first stop, by hand; this will take a while, especially if the forge is far away.

Once the minecart is in place, dwarves should fill it with blocks from the input stockpile, which will in turn be filled with blocks from the workshop where your mason has been toiling dutifully. When the minecart is full, the blocks will be dumped into the 1x1 stockpile on the right. Automatic quantum dumping!

=== Troubleshooting ===

Because of the complexity of the system, all but the most careful and experienced minecart users will encounter issues. Most route issues can be diagnosed and fixed from the {{k|h}}auling menu.

'''Symptom:''' {{DFtext|! Set dir/connect track|6:1}} message appears to the right of one or more stops

'''Possible Causes:'''
* The departure direction of the stop might be invalid. Edit the stop using {{k|Enter}} and press{{k|d}} until it is pointing in a valid direction.
* The track stop might not be built on top of a track. The track stop must be deconstructed to remedy this issue.
* Your track might not be built correctly. Make sure all connected tracks between destinations are not one-way tracks.
** This can be especially confusing with ramps. To carve a two-way track on a (natural) ramp, you must designate the ramp and one square beyond in the direction you want the track to go.
** Ramps '''must''' have a solid block on the side opposite to the track, or they will neither work nor be marked as "unusable". The solid block can be natural or constructed.
* The desired/kept items might not be configured correctly.

'''Symptom:''' The status '''0% V''' always appears to the right of one stop.

'''Possible Causes:'''
* The stop may not be set to take from a stockpile. Edit the Stop using {{k|Enter}} and make sure you see a message like "Take from Stockpile #1".
* The take conditions must correspond with the contents of the stockpile.
* The track stop may be set to dump. A track stop set to dump cannot be filled. You must either set the stop to a time-based departure or deconstruct the track stop and rebuild it without dumping. (Alternatively, with [[DFHack]] you can modify "Dump on arrival" to "No" using the {{key|q}} menu without rebuilding the stop.)
* Make sure the minecart itself has not been designated to be dumped (such as when using mass-dump).

'''Symptom:''' Dwarves fill the minecart properly, but will not move it thereafter.

'''Possible Causes:'''
* The minecart may contain items which are not included in its current stop's desired items. Check inside the minecart using the {{key|k}} and {{key|z}} keys and ensure that all items in the cart are desired items.
* The minecart may contain desired items in bins. Minecarts seem to have problems realizing that they are in fact full of desired items if some of those items are in bins, even if bins are also among the desired items for that stop. '''This cannot be solved by adding the appropriate bins to the stop's desired items.''' Either disallow bins in stockpiles you intend to load minecarts from, or set the departure conditions to rely only on percentage of total load rather than percentage of desired items using the advanced conditions menu ({{key|C}} key).

'''Symptom:''' Dwarves repeatedly attempt to load the minecart, but no items are ever loaded into it.

'''Possible Causes:'''
* This can be caused by using a Track Stop with autodumping enabled at a loading site. Every time a dwarf places an item into a cart resting on such a track stop, the item will be immediately dumped, causing unlimited, useless cart loading jobs. Autodumping Track Stops should never be used at a loading site.

'''Symptom:''' A dwarf picks up the minecart and carries it to its destination.
* See [[#Quirks|Quirks]]

=== Danger ===
Minecarts are not without <strike>danger</strike> [[fun]]. Although designating a track automatically sets the [[traffic]] designation to low, dwarves ''may'' still walk on them, and [[creature]]s ignore traffic designations altogether. If an unlucky dwarf or creature fails to [[dodger|dodge]] a minecart, they can be injured. Most of this danger can be avoided by setting the minecart {{k|h}}auling commands to guide instead of push or ride (dwarves guiding minecarts will ignore traffic restrictions), as well as by [[pasture|pasturing]] domestic animals and preventing the access of other creatures to the tracks. Note that removing the track doesn't reset that tile back to normal traffic priority, so you may wish to manually clean up traffic designation afterward. Also note that bridges that are used as tracks don't have their traffic priority changed automatically (since they're just normal bridges), which could cause dwarves to pathfind normally through dangerous minecart entrances in your fort's walls if you're not careful.

The only <s>fool</s>''dwarf''-proof method is to make the tracks inaccessible. There are several ways to create a track which works for minecarts but doesn't allow creature-traversal; the simplest is perhaps building a [[statue]] on the tracks. Other options include adding single-tile holes (minecarts moving at reasonable speed will jump the gap), vertical drops, minecart-triggered doors, small pools of liquid (4/7 water or 2/7 magma), and hostile creatures overlooking the tracks. For safety, both ends of the track should be isolated, making the dangerous center sections completely inaccessible (though maintenance access can be provided by a locked door).

Danger does not always involve living victims: careless route designation can also result in minecarts careening off tracks or colliding with each other. If this occurs, the [[item]]s may be scattered; this can cause even more hauling jobs than the minecart aimed to eliminate. Even <s>better</s> worse, scattered items, especially [[weapon]]s, can injure passing [[dwarf|dwarves]] or other [[creature]]s; in the words of Toady One the Great, "Accidental grapeshotting of the dining room should be possible now."

Of course, the danger of using minecarts means they can also be [[Trap_design#Minecarts|used as weapons]] by imaginative players.

== Advanced usage and automation ==
Minecart-specific effects are implemented via track stops, rollers and [[pressure plate]]s with "track" condition set. Since all three are considered [[building]]s, they can't be built on the same square (however convenient track stop + pressure plate would be) nor a simple ramp, and are removed by {{k|q}} {{k|x}}.

=== More on Track stop ===
Track stops are constructions that allow further automation of minecart systems via adjustable features such as braking by friction and automatic dumping of contents. They can be built from logs, bars and blocks through {{K|b}} {{K|C}} {{K|S}}; friction amount, dumping toggle and dumping direction must be set '''before''' construction, and these settings can be neither changed nor seen thereafter; however, track stops can be linked to [[pressure plate]]s or [[lever]]s to toggle friction and dumping On or Off (trigger state is inverted: switch On = track stop Off).

If a [[stockpile]] is placed on the tile that a track stop is set to dump to, it can act as a [[Exploit#Quantum_stockpiles|quantum stockpile]] and any items dumped from a minecart that match the storage settings of the stockpile will remain there and accumulate. Normally trackstops are built on top of existing track to operate on moving minecarts, but they can also be used without tracks to create [[Exploit#The_Minecart_Stop|automatic quantum stockpiles]] (see also [[#Step-by-step_tutorial|step-by-step tutorial]]). It is not always desirable to collect ALL of certain items into one quantum stockpile, such as when distributing a material to multiple separate industries. You can link your quantum stockpile to various other stockpiles, ensuring that your dwarves will keep them supplied as necessary. Because quantum stockpiles never fill up like regular stockpiles, it may be a good idea to add a switch to turn them off.

Items dumped from a minecart at a track stop (or dumped by any other means) into open space fall through z-levels until they land on a solid surface. Items falling onto a designated [[stockpile]] will automatically be considered part of that stockpile, even if the stockpile is set to disallow those items (they will, however, be automatically moved to a more appropriate stockpile, if available). Items falling on top of a minecart will '''not''' fall "inside" the minecart. Use with caution; dwarves have fragile skulls.{{bug|5945}}

=== Automated propulsion ===
==== Roller ====
{{Main|Roller}}

A '''roller''' is a [[power]]ed [[machine component]] for the automated propulsion of minecarts. They are built over the top of existing tracks with {{K|b|M|r}}, requiring a [[mechanic]], ''(length/4)+1'' [[mechanism]]s and a [[rope]]. Rollers may also be placed directly on ramps to help pull carts up Z levels. Rollers are very useful to maintain a cart's momentum along long routes, to get them to climb Z-levels without dwarfpower involved, and to get them to reach speeds unattainable by guiding dwarves. These devices are variable-length (1-10), variable-direction and variable-speed ([[Minecart#Numbers_behind_the_scene|see below]]), all traits that can be set at construction time; a roller uses two units of power per tile it is long.

Single-tile rollers transfer power in all four cardinal directions, while other rollers generally only transfer power perpendicular to their activity direction. Longer rollers can also transfer power along their activity direction if built in the correct order, although this can be hard to accomplish and is easily broken. Rollers cannot be powered from above.

Rollers have great acceleration and capped speed. Carts going faster than the roller are unaffected. If a cart moves across an active roller in the direction the roller works and moves slower than the roller's specified speed, the cart will be set to the roller's speed. A cart going against a roller's movement direction will be sent back the way it came (once again at the roller's speed), unless it was moving extremely fast: speed increment of 100000 allows to reverse carts from the full "highest" (50000) speed roller to full "highest" speed back, but ramps can accelerate a cart beyond this. {{cite forum|144328/5702453}}
A cart crossing over a roller perpendicular to its current movement direction will gain the roller's amount of speed in the perpendicular direction without directly changing its forward motion. Without an adjacent wall to constrict its movement, this will typically send a cart off the rails on a diagonal path, completely unable to follow any tracks until it collides with a wall or is otherwise brought to rest. However, if the roller is placed over a track turn and pushes ''from'' the direction of that turn's track, the turn affects carts ''after'' the roller, so they will be forced into the turn rather than derailed in a diagonal direction. {{cite forum|144328/5702453}}

{{diagram|spaces=yes|\
tracks: full:
║ ║
═╗═ ═╢═
║ ║

╢ : roller pushing from W to E
}}
If the roller is powered, carts from ''all'' directions (unless too fast) exit S, because speed imparted by the roller forces carts toward E and ''then'' into the turn.
If not powered, carts from W and N exit S, carts from E and S exit W. Carts above derail speed will ignore the turn, of course.

{{diagram|spaces=yes|\
║ ║
═╗═ ═╟═
║ ║

╟ : Roller pushing from E to W
}}
Carts from the E or W: exit W.
Carts from N: derailed diagonally, exit SW.
Carts from S: derailed diagonally, exit NW.

Rollers affects carts on a track - if placed on a floor or ramp without any tracks, they are ignored. Depowered rollers are also ignored, friction is determined by the tiles underneath.

Because of their one-way nature, rollers are unsuitable for most two-way minecart tracks (unless you set gears toggling roller A->B off while toggling A<-B rollers on). However, a minecart set to be ''guided'' is not affected by rollers at all{{cite forum|109460/3286235}} — this allows a one-way track to be used in both directions. In addition, unpowered rollers do not affect minecarts.

Care must be taken in [[glacier]]s and other extremely cold [[biome]]s, since rollers (and the machinery used to power them) will not operate when constructed on natural [[ice]] floors.

==== Impulse ramps ====
Carts can be given momentum without rollers or changing z-level through a phenomenon called "impulse ramps". A track ramp which is connected both to a wall and to a floor will ''always'' accelerate a cart towards the connected floor tile, no matter where the cart enters the tile from. This means carts can be accelerated as though dropping z-levels, even if the cart doesn't actually change z-level at all. If a track ramp faces three directions such as ╩, then two of those directions need to be facing walls for the cart to be accelerated towards the remaining direction.

Example of straight impulse acceleration:

{{diagram|spaces=yes|\
▒▒▒▒▒▒▒▒▒▒ ▒▒▒▒▒▒▒▒▒▒
═▲▲▲▲▲▲▲▲▲▲═ ═╚╚╚╚╚╚╚╚╚╚═
▒ : Wall
═ : Normal track
▲/╚ : N/E Track/Ramp
}}

If a cart enters from the left, it will speed up on every track/ramp and exit to the right going very very fast - more than one tile every step. If it enters from the right then it will bounce back impulsed by the ramp if it's going slow enough.

As another oddity, carts coming from ramps will in some cases "teleport" through most of the next tile. This can be used to send carts up levels with minimal loss of speed. You can just make an upward spiral alternating impulse ramps and regular upward ramps. It takes no power, is quick and cheap to build, requiring only channeling and track carving, and the cart goes up fast, but not so fast that it launches its contents.

Example of an impulse elevator:

{{diagram|spaces=yes|\
z +0 z +1 z +2 z +3
░░░░░ ░░░░░ ░░░░░ ░░░░░
░╔░░░ ░▼╚╗░ ░░▼▼░ ░░░░░
░╝░░░ ░▼░░░ ░░░╔░ ░░░▼░
░▼▼░░ ░░░░░ ░░░╝░ ░╚╗▼░
░░░░░ ░░░░░ ░░░░░ ░░░░░

░ : Wall
╔,╚,╗,╝ : Track/Ramp
▼ : Down Ramp (empty space)
}}

Note that this impulse elevator, due to the checkpoint effect and upward ramp curve effect, will not actually result in carts traveling straight up the ramp. They will lose speed, bounce off a ramp, then be accelerated back into the spiral after a 9-turn delay on both tiles on the floor where they are stopped. Initial acceleration will carry the cart up a variable number of floors before this effect occurs, but this bouncing back and forth will occur every 5z-levels after the first. When the cart ''is'' traveling upwards, it will pass every tile at a rate of one tile per turn regardless of its actual speed, due to the checkpoint effect. In tracks with only a single cart, this is negligible, but when multiple carts are on the same track (such as when you place multiple carts on a magma cart lift) this can cause collisions which derail carts or cause other unexpected or undesired behaviors.

A sort of opposite effect to impulse ramps also exists: ramps lacking the proper "up" and "down" connections are treated as flat track, even if they actually go up or down z-levels. This allows building "anti-impulse" slopes consisting entirely of ramps only connected up, which a minecart can travel up forty levels and more, needing no more than a single push.

=== Controlling traffic ===

==== Switching ====

As constructions or tile features, [[door]]s and other furniture can be built on tracks. A [[door]] or [[floodgate]] can be turned on or off by a [[lever]], effectively controlling the flow of automated minecarts. This may be <s>dangerous</s> [[fun]], however.
{{diagram|spaces=yes|\
->
A ════┤≡════ B
┤ : roller pushing to East
≡ : door
}}
The roller pushes the cart east, but until the "departure condition" is fulfilled, the door remains closed and blocks the path.

[[Bridge]]s can also act as tracks, but only if they're lowered or not retracted. This property can enable levers to turn tracks on and off. However, care should be taken to ensure that such bridges are never operated while a cart is on top of them, as the cart will be flung off the track. It's worth noting that it's often faster, and cheaper, to construct large bridges than long sections of constructed track.

A powered track switch can be constructed by building an "inverted" corner as illustrated below.
{{diagram|spaces=yes|\
B B
║ -> ║
║ ║
════╚═══ ════├════
A C A C
├ : roller pushing to West.
}}

If the cart is pushed East from the stop at 'A' while the roller is activated, it will arrive at 'B'. If the roller is not running, it will arrive at 'C'. The switch works by the roller first reversing the incoming cart's movement and the cart ''then'' following the track corner.

This switch is very reliable, reacts instantly to on/off signals, and carts of any speed can be switched by this design, although very fast carts will require rollers that are several tiles long, up to three. The requirement for power can be inconvenient or impractical. Non-powered solutions may use controlled derailment, or a connecting bridge.
{{diagram|spaces=yes|\
B ╥
║
║
╞════╝ ════╡
A D C
}}
Here the track between A and C is not continuous. The only continuous track is A->B, with a corner (not a T section). Fast moving carts will tend to derail at D and rejoin the track to C. Placing a door at D will prevent the derailment, so the cart continues to B. The door is operated by mechanisms elsewhere (typically, a lever, but some fun can be had with pressure plates).

Since it depends on derailing, this switch requires a very fast cart, faster than what can be achieved with rollers alone. To gain sufficient speed, a cart must be accelerated further, usually by descending several levels or through impulse ramps. The high speed makes the cart much more dangerous and harder to control.

If carts are moving too slowly to derail at the corner, a retractable bridge may be used as a connector between A and C.
{{diagram|spaces=yes|\
B╥
║
║
A╞════bbb════╡C
}}
The bridge must overlap the corner. Bridges behave like a track crossing, allowing carts to pass in a straight line. When retracted, the corner reappears, so the carts will continue to B. Bridges take 100 steps to react to a signal, necessitating rather long "lead times" when switching tracks via bridge.

As mentioned above, special care must be taken to make sure the bridge doesn't change state while the cart is passing over it. Retracting bridges will throw the cart, causing it to stop dead. Raising bridges can even crush the cart.

==== Controlling Speed ====


Minecarts can reach extremely high speeds, especially when descending multiple Z-levels. A minecart will derail at a track corner if its speed exceeds 0.5 t/st (tiles per step), '''unless''' the route in the direction of travel is blocked:

Will derail at > 0.5 t/st:

{{diagram|spaces=yes|\
in ══╗ -> derailing
║
out
}}

Will not derail at > 0.5 t/st:
{{diagram|spaces=yes|\
in ══╗O
║
out

O : wall/column.
}}

This behavior can be used to build a "speed limiter", that will ensure that when a minecart exits it is traveling below derail speed:
{{diagram|spaces=yes|\
░░░░ ░░░░░ ░░░░░
in ═╔═╗░ ░╔S╗░ ░╔S╗░
out ═╬═╝░ out ═╗═╝░ out ═╗═╝░
░╚S╝░ ░╚═╝═ in ░╚S╝░
░░░░░ ░░░░ ║░░░
in
░ : wall
S : Track Stop (High Friction or lower)
}}
If the minecart is traveling below derailment speed, it will not be affected; if above, will be slowed down and checked again. Granted, you could do the same just with track turns, but it may take a lot of turns and time.

Since all the derailings, bounces and ramps can impart a sideway component of speed small enough to start visible drift many tiles away (say, [[Fun|in the middle of a bridge]]), track turns have one more use: forcing the carts to move strictly along the grid directions. Carts passing a turn below derailing speed convert one component of velocity into another, thus eliminating the drift.

=== Loading liquids ===
[[Water]] and [[magma]] can also be loaded into minecarts by submerging them to a depth of at least 6/7 while standing still or moving at speeds of at most 10000. Loading fluids onto minecarts can be difficult because the added friction provided by fluids can stop a cart in a submerged tile. Curiously, filling a minecart with magma does not injure a dwarf ''riding'' it. A minecart will hold enough fluid to increase the depth of a single tile by 2. This amount is listed as 833 units, which weigh 459Γ (water) or 999Γ (magma). An iron or steel cart filled with magma weighs 1313Γ, while an adamantine cart filled with magma weighs 1007Γ. Since you need a minecart above the liquid's level, possible arrangements may include pressure-activated sluices, rollers (with magma-safe chains for magma), pouring from above to "submerge" it briefly on the same level and drain excess away (dig deeper and leave a vaporizer, though if you could have power for rollers, may as well use a pump) and exploits with ramps (not necessarily impulse ramps, "same height" passing dip does it).
The liquids can be dumped by a constructed track stop.

== Quirks ==
This little quirk concerns dwarf-managed minecarts. If a track which was previously open becomes blocked (ex. flipping a switch connected to a floodgate you've built on the track to raise it) and the conditions for departure are met, instead of refusing to ride/guide the minecart or ride/guide it until it reaches the obstacle, the dwarf will pick up the minecart off the tracks and haul it to its scheduled destination on foot. If the distance is long enough and the weight of the cart heavy enough (due to being filled with heavy items such as stones), the dwarf may drop the cart because of fatigue/hunger/thirst before reaching the destination. This will cancel that vehicle setting job and make another dwarf come by and attempt to haul the cart to the nearest appropriate stockpile where another dwarf will pick up the cart and attempt to haul it to its initial stop. If the stockpile is far enough from initial stop, this second dwarf who is attempting to place the minecart on its tracks may also drop the minecart out of fatigue/hunger/thirst creating a loop that will go on until a dwarf with enough endurance manages to place the minecart where it belongs.

In fact, it seems dwarves are more than happy to attempt to carry a minecart from one stop to another even if just waiting until the track is open again would be the more sane option.

Dwarves will also carry a minecart to its next stop if the direction specified is incorrect (or invalid). This can often occur when using the default departure settings and forgetting to set the direction of each condition.

Dwarves can admire buildings while riding mine carts. Dwarves will not fall asleep during a ride (at least not from being drowsy). If riding on a continuous powered track loop, the dwarf will die of dehydration/starvation as they can not jump off to get sustenance{{cite forum|109460/3377228}}. Dwarves riding in submerged minecarts will gain experience in [[swimming]].{{cite forum|129889}}

Tracks block wagon access to trade depots, unless they're on a ramp. [[Bridge]]s can also be used, as they function as tracks but do not block wagons.

== Physics ==


Minecart physics depend greatly on the departure mode set in the route stop conditions.

When set to "Push" or "Ride", minecarts will move according to the regular laws of momentum, gaining speed when going downhill, losing it slowly due to friction when on a flat plane, and more quickly when going uphill. In these modes, minecarts will move in a straight line until they either are brought to a stop by friction or an obstacle, or until they encounter a turn. A minecart will roll straight past "blocked" ends of T-junctions or track ends, they have no power to restrict a cart's movement. The cart's behavior is largely independent of the weight of its contents (including fluids and dwarves): heavily loaded carts gain more momentum when accelerating, but this only plays a role in collisions: a heavy cart gains just as much speed and is as easy to stop as a light one. In either case, dwarves can not push nor ride an unpowered cart up a ramp, bouncing back the direction it came. At best, this is a waste of time; at worst, it will give your cart-pushing dwarf a [[fun|fun surprise]]. To solve this, the player can either use Rollers (see below) or set the cart to be Guided.

The difference between "Push" and "Ride" is whether the dwarf will go along with the cart or not.
{{DFtext|Push}}: the dwarf will give the cart an initial push, not enough to go up a ramp, but enough to go some way along flat track, and the dwarf will remain at the first stop, ready for a new job.
{{DFtext|Ride}}: the dwarf will give the cart the same initial push and then hop aboard the cart riding with it to the next stop.
{{DFtext|Guide}}: minecarts seem to ignore all laws of physics. That is:
*Ignore the weight of any and all items inside. Therefore:
**Move at the speed of the dwarf that is guiding them. It is thus recommended to pick the most [[attribute#Agility|agile]] of your dwarves for cart-guiding tasks.
*Ignore working rollers.
*Will ''not'' collide with other guided carts even when a full frontal collision would be expected.
*Will go up ramps like nobody's business.
This is therefore the recommended method of transport for simple non-powered rail systems, despite it diverting a dwarf from other, potentially more important tasks.

Some samples with behavior:
{{diagram|spaces=yes|\
A <-> B A <-> C A <-> B
B B B
║ ║ ║
A══╝ A══╩══C A══╬╗
You can only go A->B ╚╝
Works when the cart Works
is in Guide mode.
}}
In the second example above, a cart "pushed" from B will go over the junction and roll off into the unknown south.

=== Track Direction Irrelevance ===
Carts that are traveling independently, (that is, not guided,) only care that tracks ''are'' on the tile, not which direction the tracks actually move. Tracks respect only curves (with two exits) and ramps.

This means, for example, that the following tracks, when a (non-guided) cart travels from West-to-East, are functionally identical in effect:

A════════════B A╬║╚╔╣╩╦╠╥╨╞╡B

This is because so far as the cart is concerned, only ramps and curves with two exits where the exit in the path they are traveling matters.

Carts only check for curves when they are halfway through a tile. When they get there, they look to see if their path has no exit. (That is, if it is traveling East, it checks if there is an East exit.) If there is, it ignores all other track directions, and keeps traveling. If there is not, it checks to see if there are only two exits to the track, and if one of those directions was the direction it "came from". (That is, if traveling from the East, it checks if there is a valid exit to the West, and if so, if there is either a North exit or a South exit.) If there is not, it ignores the track anyway, and keeps on traveling as though it were still on track. If there is, it will subtract 1000 from the velocity of the cart, and redirect all forward velocity to the direction of the curve. This change in the direction of velocity ''overwrites'' any "diagonal" velocity, which can prevent diagonal velocity derailments, but any perpendicular velocity is not preserved, and is instead discarded.

=== Invalid Ramps ===
Ramps are functionally defined for cart purposes as being a tile which exerts an acceleration force upon its "downward slope". This downward slope requires a cart to have one ''and exactly one'' carved exit to the tile that is the "bottom" of the ramp. Ramps push carts in this "downward" direction (possibly leading to diagonal movement, below), and the deceleration of an "uphill" ramp is actually just the acceleration being applied against the direction of a cart's movement.

This is where players can find an exploit in the behavior of ramps - if there are ''two'' "downhill" exits to a ramp (such as a "T junction" on a ramp where only one exit faces a wall), then the ramp provides no acceleration ''or'' deceleration, allowing carts to travel up ramps without any loss of momentum except for the standard "flat track" deceleration, because as far as the cart is concerned, the track ''is'' flat.

Similar effects can be achieved when there are ''no'' "downhill" exits to a ramp. This may be the case if you have, for example, an East-West track with a one-tile channel with a ramp in it. The cart will travel through the "dip" with no change in velocity. It can also be the case if you abuse the Track Direction Irrelevance, above, and set only exits ''up'' the ramp, and none leading ''down'' the ramp. For example, if a cart is traveling from West to East up a slope, only carving East exits on each tile of ramp will make the cart travel up the ramp, and then recognize the tile it is on as being a "flat" tile, thus ignoring any deceleration from traveling uphill. Note that this effect only reliably occurs at relatively slow speeds (at around push, or single accelerating ramp speeds) as the cart may simply ignore the ramp and crash into the wall at higher speeds.

=== Skipping ===
If a minecart is moving fast enough, it can skip over [[water]] or [[magma]], making splashes of [[mist]] (or [[magma mist]]) as it attempts to move on them horizontally. This horizontal movement is independent of the minecart and its content's [[weight]].

=== Track Jumping ===
If a minecart encounters the end of the track or a T junction with no "exit" in its movement direction, it will simply leave the track and continue on its course in a straight line until it encounters an obstacle, slows to a stop, or encounters another (properly aligned) Track even if the tile at which it joins the new track instantly sends it around a corner.

Tracks that are travelling at high enough velocity will also start "jumping" the track if it hits an un-tracked tile (flying over and ignoring any tracks) until it is ready to land. Carts that land upon tracked tiles re-rail themselves, and clever designers use this feature to jump over curved track sections in one direction or another. (Retracting bridges over untracked tiles can cause jumps or not cause jumps depending upon the status of the bridge.) Minecart speed must be carefully regulated to ensure reliability of jump length.

Carts that approach a downward slope at a high enough velocity will also make a jump, but will not do so if the Checkpoint Effect (below) is exploited through an impulse ramp before the actual downhill as the impulse ramp "tricks" the cart into thinking it has already started going downhill.

=== Corner Ramp Derail ===

Corners on upward ramps can cause diagonal movement, forcing a derail even if the cart has a wall next to it, which will force a stop when it touches a wall that forces dwarves to manually reset the cart.

This is caused by the fact that a cart, after turning the bend in the track halfway through the length of the tile, will still "accelerate down", which is now perpendicular to the movement of the cart, causing acceleration to occur in two directions. (Down corner ramps do not have this problem, as when they pass the halfway point, all perpendicular motion is added to forward motion, and after that curve, all downward acceleration is in the forward direction.)

There are two fixes to this problem. One is to simply not put corners on up ramps. The other is to take advantage of the Checkpoint Effect, below, by making a ramp (possibly including an impulse ramp) one tile in front of the ramp to make it skip through most of the tile before sideways momentum can be built.

=== Checkpoint Effect ===
The checkpoint effect, [http://www.bay12forums.com/smf/index.php?topic=144328.0 explained in depth by Larix], is an odd and highly exploitable feature of ramps where minecarts "teleport" through the next tile of track, ignoring nearly all minecart physics (except that they stop at all walls or other obstacles and not only respect curves, but will take them even when they would otherwise derail) and passing through that tile in just a single tick, and into the next tile at the halfway point.

This effect occurs when a cart leaves a downward ramp for any other direction of tile. (This includes ramps which accelerate in different directions, even a ramp which goes from accelerating East to accelerating North due to a bend in a chain of standard down ramps in a curve.) This allows, for example, two valid straight ramps directly next to one another with a cart dropped onto one or the other with no momentum to have the cart pick up acceleration going "down" the ramp as normal, but then flying up through the "up" ramp it travels into with no loss of momentum, as though it had come from an impulse ramp. If the two ramps had at least one space of distance between them, and then a cart were dropped in, the cart would instead "rock" back and forth between the two ramps.

This seems to be because ramps have a slightly longer length than regular tiles - 144,000, rather than 100,000 distance. When this "snaps back" after a ramp, it seems to project the cart suddenly further along the track, making it jump a tile ahead even when otherwise moving at relatively low speeds.

This [[bug]] is the cause of a ''wide array'' of unexpected behavior among people who do not take this bug into account. It causes derailments or failure to climb up seemingly valid impulse elevators. In general, it makes a system that behaves extremely counter-intuitively, and operates ''any time a cart encounters a valid ramp''. At the same time, when its effect is accounted for, it is highly exploitable: It causes "perpetual motion devices" using no power when two opposing ramps are placed next to one another, since the "uphill" effect of the opposing ramp is ignored, preventing deceleration.

Another useful thing to note about this exploit is that carts traveling at no less than 72,000 or so speed (enough to travel half a ramp tile in a single tick) can travel through every tile in just one tick at no change in velocity as long as the tiles alternate between impulse ramp or actual down ramp and any other tile type. The cart checkpoints through the non-down-ramp tiles, and can pass through the (impulse) down ramp tiles in a single tick, before they can actually start gaining momentum.

=== Falling ===
When falling, a minecart appears to cause no damage upon collision, possibly to allow cart "stacking" across Z-levels.{{cite devlog|2012|04|06}} A dwarf riding in a minecart that is dropped multiple z-levels suffers normal fall damage. Minecarts can fall through up/down stairs.
The cart falling (from a hatch, thus with no horizontal speed) onto a track ramp is accelerated as if starting from the middle of the ramp - i.e. to the same speed, no matter how many Z-levels it was dropped, vertical velocity is negated. {{cite forum|144328/5701211}}

=== Stacking ===
If a minecart lands on top of another minecart, they may form a stack, with the upper cart on the z-level above the lower. Subsequent carts do not form a stack, but rather quantum stockpile in the same space. This behaviour is useful for [[megaprojects]] and [[trap design]] with minecarts as the weaponry. Moderation should still be exercised: carts take longer to fall into a "stacking" tile already occupied by other carts and will spend that time "hanging" in the air above the stack. This can lead to following carts striking them, which can cause all kinds of malfunctions. The extra time is two game steps for every cart already in the stack, which doesn't hurt stacks of ten carts very much but makes stacks of 100+ rather impractical.

These minecarts on the upper level generally need to be struck with another minecart to move out, or have their support removed. The latter option is safest done by shooting it away with another minecart, manual removal of a stack-supporting cart typically causes the next cart from the stack to [[fun|fall on top]] of the hauler.

=== Perfectly Elastic Collisions ===
Minecart collisions are perfectly elastic, meaning that not only do minecarts not take damage, but that two carts that are rolling which have frontal collisions of near-similar speed, and where one cart is no more than twice the mass of the other cart, will result in a billiard-ball-like effect of the lighter cart bouncing off the heavier cart with a proportional speed increase dependent upon the relative momentum behind the heavier cart.

Using this trick with carts already at the 270,000 maximum speed from ramps can result in "supersonic" carts traveling at speeds in the millions (travelling a dozen tiles per tick), but where they are suddenly subject to 10,000 units of "terminal velocity" friction per tick. [http://www.bay12forums.com/smf/index.php?topic=137557.0 Thread with SCIENCE here].

While hypothetically capable of launching a minecart into orbit when used in conjunction with a ramp, no cargo can be contained in the launched cart, as the collisions will force ejections of the cargo. Your "unwilling volunteer" [[goblin]] space pioneers will simply become paste underneath the wheels of an extreme high-speed cart.

=== Numbers behind the scene ===

According to early research by '''expwnent'''{{cite forum|112831/3536975}}:

The minecart has a variable for speed. Speed is measured in tiles/100000 ticks, so a speed of one hundred thousand means one tile per tick. By going down a large number of ramps, a maximum speed of 270,000 can be reached, which presents the limit for most practical applications. Short bursts of (much) higher speeds are possible through carefully planned collisions of high-speed carts {{cite forum|137557/5145499}}.

Every tick the cart accumulates distance units, as well as slows down depending on current tile (speed is reduced by "friction" of the tile). The cart will move to the next tile the tick before accumulating 100000 distance units, (or several tiles in case of great speed), then the leftover distance units are added to the default 100000 distance u. of the next tile. Since most deceleration and acceleration is applied per step, with the notable exception of corners, a cart going at twice the speed of another one can cover about four times the distance in a straight line, but only twice the distance along a winding track with very many corners.

A push will teleport a cart to the beginning of the next tile (NOT the middle!) in one tick with 19990 speed (10 speed is lost due to track friction), while a roller will give a cart the roller's set speed, and it will start to accumulate regular track friction past the middle of the roller tile. Some track features will affect a minecart when it is past the middle of the previous tile: entering a ramp or a hole/drop will happen when the cart has left the middle of the previous tile, and the ramp will gain additional distance unit depending on the leftover units from the previous tile. When a cart leaves a ramp it will emerge after one tick in the middle of the next regular tile, so its entry coordinate is "50000-speed+friction". Rollers also affect the speed of minecart from the middle of the previous tile.

Friction of tiles:
{| class="wikitable"
|-
! Tile
! Friction
! Comment
|-
| Tracks
| 10
|-
| Ground/Floor
| 200
|-
| Unusable ramp
| 10
|-
| Upwards ramp
| 4910 (10+4900)
|-
| Downwards ramp
| -4890 (10-4900)
|-
| Roller
| ±100000 (but capped by the set speed)
|-
| Corner track
| 10
| Speed reduced by 1000 upon leaving the corner tile
|-
| Track stop (highest)
| 50000
|-
| Track stop (high)
| 10000
|-
| Track stop (medium)
| 500
|-
| Track stop (low)
| 50
|-
| Track stop (lowest)
| 10
|-
| Water 1-6
| Additional (WaterLevel - 1) * 100
| rowspan="2" | [[#Skipping|See Skipping]]
|-
| Magma 1-6
| Additional (WaterLevel - 1) * 500
|-
| Empty space
| 0
|}

Water of depth 7/7 provides a friction of about 10000 per step, as does maximum-depth magma. This higher friction may not apply to very slow-moving carts.

Impulse sources:
{| class="wikitable"
|-
! Feature
! Speed
|-
| Push
| 20000
|-
| Roller lowest
| 10000
|-
| Roller low
| 20000
|-
| Roller medium
| 30000
|-
| Roller high
| 40000
|-
| Roller Highest
| 50000
|-
|}

== Non-standard uses ==
Minecarts include some interesting characteristics that have motivated uses beyond hauling. They can be useful for creating fully-automated [[exploit|quantum stockpiles]] and [[garbage disposal]]s. Storing perishable goods (meat, meals, etc.) inside a minecart appears to guard against rot and vermin.
Minecarts can be [[Trap_design#Minecarts|used as weapons]], or as (hopefully non-fatal) triggers to restart stalled [[healthcare]]. They can also be used to time/control game events, either using a basic [[repeater]] or much more advanced [[minecart logic]].
Minecarts trigger [[pressure plate]]s, which means a trap can be designed to trigger when a thief attempts to steal a minecart.
A pressure plate can be used as automatic and more precise custom "launch when full enough" system - as long as weight of your minecarts stays the same. You cannot build a hatch or roller on the same tile, so launch by bumping with another cart. {{cite forum|15096/4580050}}
Dwarves riding minecarts can attack enemies within reach (which goes back to dev log). This applies to shooting, and they actually can hit targets while riding by.{{cite forum|109460/5266119}} Whether a minecart protects the rider and how it interacts with dodging is not known yet. Minecart riders can also [[Swimming#Minecart_training|train swimming]] and [[Megaprojects#Surveillance_Track|detect ambushers]].

== Adventure mode ==
In addition to being used for hauling, minecarts can also be ridden in [[adventure mode]]. (Adapted from forum thread {{cite forum|122903/4258212}})

# If the minecart is in your inventory, drop it. If it is already on the ground, proceed to step 2.
# Press {{k|u}} when you are 1 tile away from the minecart (or standing on the same tile as the minecart).
# You will be presented with the following options:
[[File:minecart adventure mode menu.png|left]]
{{clear}}
* If you {{DFtext|Push}} the minecart, it will move a few tiles in the direction you chose. Physics comes into play here, so it will gain/lose speed depending on the usual factors.
* If you {{DFtext|Ride}} the minecart, you will hop into the minecart, even if you were a tile away, and it will move in the chosen direction with you in it. It will gain/lose speed depending on the usual factors. Whilst the minecart is in motion, you should press {{k|.}} to skip your turn; if you attempt to move whilst the minecart is still in motion, the laws of physics come into play, and you will take [[wound|damage]]. Alternatively, you can push the minecart whilst it's still in motion (although it's unclear how one can bend [[physics]] so as to push a moving minecart whilst inside the minecart). If you push it in the same direction you are already travelling in, you will greatly increase the minecart's velocity. You can also push it in different directions, and this will cause it to gradually change direction-the amount of pushes this requires depends on the minecart's velocity. Once the minecart has stopped moving, you may move out of it safely, or you may want to give it another push. Note that if you push a minecart right after having ridden it (still on the same tile as the minecart), it will act as though you chose to ''ride'' it.

If you want to test this out without creating an adventurer, the [[object testing arena]] allows you to spawn minecarts ({{k|k}}-{{k|c}}-{{k|n}})

== Forging and Melting ==
* Metal minecarts cost '''two''' [[metal]] bars to forge, or '''six''' [[adamantine]] wafers.
* When a non-adamantine metal minecart is melted down, it will return '''1.8''' metal bars, for an '''efficiency of 90%'''.
* When an adamantine minecart is melted down, it will produce '''1.8''' wafers, for an '''efficiency of 30%'''.

== See also ==
* [http://www.bay12forums.com/smf/index.php?topic=109460.0 The "How Does Minecart" Thread] by '''Girlinhat''' et al.
* [http://www.bay12forums.com/smf/index.php?topic=112831.0 SCIENCE: Quantifying minecart physics] by '''Snaake''' et al.
* [http://www.bay12forums.com/smf/index.php?topic=129676.0 How to build a Multi-cart Ore to Magma Minecart Project without needing power] by '''WanderingKid'''.
* [http://www.bay12forums.com/smf/index.php?topic=144328.0 My very own Minecart Education Thread. Ten Lessons, now complete.] by '''Larix'''.

== Bugs ==
*A dwarf will drop her [[child|baby]], if she has one, when boarding a minecart set to be ridden.
*Dwarves have no concept of traffic safety and will walk into busy minecart lines to retrieve objects, often with deadly consequences. This is especially problematic in [[Swimming#Minecart_training|clever applications]] depending on dwarves riding the carts very frequently, because they have a bad habit of dumping their worn clothes on the tracks after a minecart ride. Adding an automatically-operated [[hatch cover]] at the end of such a ride can help prevent [[unfortunate accident]]s.
*Dwarves cannot guide a minecart through an unlocked door unless another dwarf opens the door.{{bug|6056}}
*It is possible for a creature and minecart moving towards each other to pass without collision if they exchange tiles in the same tick.
*After a minecart ride, a dwarf will sometimes haul the minecart to a storage stockpile, leaving another dwarf to haul the vehicle back to the route.
*Minecarts falling onto a floor injure creatures in the tile below the floor.{{bug|6068}}
*A minecart's initial velocity is not affected by weight, when pushed or launched from rollers.{{bug|6296}}
*Removing a stop that has a vehicle waiting on it may cause the game to crash.{{bug|5980}}

{{Category|Fortress mode}}
{{Category|Interface}}

[[ru:Minecart]]

Minecart

2015-06-18T02:26:16Z

NW Kohaku: /* Physics */

{{Quality|Masterwork|08:15, 19 May 2015 (UTC)}}
{{av}}
A '''minecart''' is a [[tool]] intended for [[hauling]], introduced in version 0.34.08. It can be made of [[wood]] at a [[carpenter's workshop]] or [[metal]] at a [[metalsmith's forge]] (using the [[Metal crafter|metalcrafting]] labor.) Minecarts store up to five times as many items as [[wheelbarrow]]s and are quite a bit faster than dwarves hauling objects by hand, but have the disadvantages of requiring a dedicated track network, a complex route planning phase, and the possibility of dwarves [[Fun|blundering into the path of carts filled with lead ore]]. Tracks may be carved into stone, or [[Construction|constructed]]; the latter allows above-ground routes, but these are more difficult to set up due to their additional [[building material|material requirements]].

Just like wheelbarrows, minecarts are considered [[item]]s and are stored in a [[furniture]] [[stockpile]]. Despite their five-times-greater capacity, they are only 33% larger than wheelbarrows and are identical in base [[item value|value]] when made from the same [[material]] (the value may differ due to the [[item quality]]). [[thief|Thieves]] or even mischievous animals can steal minecarts, even when they are moving on a track{{cite forum|109460/3289070}}. However, minecarts moving fast enough or being ridden cannot be stolen.

Although most of the utility of minecarts is in [[fortress mode]], an [[adventure mode|adventurer]] can also ride in a minecart. Adventurers can also pick up and relocate minecarts.

The invention of minecarts revolutionized the [[minecart logic|Science of Dwarfputing]] by enabling smaller, faster logic systems to be built.

== Basic Minecart Usage ==
Minecarts can be used to swiftly transport dwarves, [[flow|fluids]], and/or large amounts of items, but before you have a functional minecart there are several preconditions that need to be met. First of all you need an actual minecart, constructed either in a [[carpenter's workshop]] or [[metalsmith's forge]]. For the minecart to be able to move you also need to carve (with {{k|d}} {{k|T}}) or construct (with {{k|b}} {{k|C}} {{k|T}}) a track, which could be as simple as a straight line. Finally you need to construct stops on your track (with {{k|b}} {{k|C}} {{k|S}}) where the minecart will start and stop.

After you have created the stops and assigned a cart to the track, you must create logic routes connecting several stops and designate starting conditions for each stop. This is done with the {{k|h}}auling key. The most basic conditions are how the cart's movement is initiated and in which direction the cart should start moving. Carts can be either be Pushed (a dwarf stands at a stop and gives the cart a single push) or Guided (a dwarf continually pushes the cart forward, guiding it along the track). The [[hauling]] [[labor]] required for pushing and guiding carts is called "Push/Haul Vehicles" and is turned on by default.

To control which items to transport you can add conditions specifying: (1) which kind of items to be loaded, and unloaded, (2) stockpile links to define which stockpile(s) the items should be un/loaded to and from.

===Capacity and weights ===
Minecarts have five times the [[Weight|capacity]] of [[wheelbarrow]]s.

'''Examples of the capacity of one cart'''
{| class="wikitable"
|-
! Item
! Amount
|-
| [[stone]]
| 5
|-
| [[wood|log]]
| 10
|-
| [[block]]/[[bar]]
| 83
|-
| [[Kitchen|prepared meals]]
| 500
|-
| [[Trap_component#Spiked_ball|spiked balls]]
| 500
|-
| [[Weapon#Native_weapons|mace]]
| 625
|-
| [[Weapon#Native_weapons|spears]]
| 1250
|-
| [[cloth]]
| 2500
|}

The weight of the loaded minecart does not affect the initial velocity received from pushing or launching from a roller. However, the load of a minecart ''does'' affect whether a [[pressure plate]] triggers or not, based on the pressure plate's setting.

'''Weights of different carts'''

{| class="wikitable"
|-
! Type of cart
! Empty cart
! Fully loaded (items)
|-
| oaken minecart
| 28Γ
| 378Γ (10 oak logs)
|-
| platinum minecart
| 856Γ
| 10482Γ (83 gold bars)
|}

The weight of a minecart is one twenty-fifth (1/25) the [[density]] of its material in Urists. Because pressure plates can be set to trigger at intervals of 50 Urists, minecarts with weights just under a multiple of 50 are ideal for switching based on whether they're full or empty. The best minecart materials for full/empty switching are as follows:

{| class="wikitable sortable"
|-
! Material !! Minecart weight !! Content weight required to trigger !! Banana roasts required to trigger (for scale)
|-
| [[Bismuth]] (moods only) || 391 || 9 || 15
|-
| [[Brass]] || 342 || 8 || 14
|-
| [[Electrum]] || 596 || 4 || 7
|-
| [[Fine pewter]] || 291 || 9 || 15
|-
| [[Glumprong]] || 48 || 2 || 4
|-
| [[Lay pewter]] || 291 || 9 || 15
|-
| [[Nickel silver]] || 346 || 4 || 7
|-
| [[Tin]] || 291 || 9 || 15
|-
| [[Trifle pewter]] || 291 || 9 || 15
|}

=== Creating tracks ===
Minecart tracks are made up of contiguous track, tracked ramp, or bridge tiles. Track tiles and tracked ramp tiles have a direction or series of directions associated with them. These directions dictate which directions a minecart on a given tile may move from that tile. For example, a Track NE (northeast) tile allows a minecart on it to move either north or east from its present position. Therefore, if you want your minecart to move east along a straight piece of track, then return west using that same track, you would need to use EW tracks so that the cart could travel east initially, then return west over the same track. Excluding designs in which the cart will "jump" tracks via a drop or other ramp, tracks must be valid end to end to work for most looped or straight-track applications. A single east only track tile in your line of east-west tracks will cause any route using the track to fail the moment it tries to go the wrong way over that tile. Minecart tracks can be built in two ways: Engraved/carved or constructed. A given minecart track need not use engraved or constructed elements exclusively, as the two methods can be used interchangeably depending on the needs of a given section of track. The way the tracks are built is slightly different between the two, as explained below.

====Simple tracks====

'''Carved'''

A single-tile wide strip of natural stone can be designated to be [[Engraver|carved]] (with {{K|d}} {{k|T}}), which will create a straight two-way track. The creation of corners, crossings, and T-junctions is as simple as designating another strip of track that overlaps an existent or newly designated track. Engraved tracks are removed by [[smoothing]] the rock they're on, which results in a smooth floor (that can be re-engraved if necessary), or by building a [[floor]] on top and subsequently removing it. Dwarves can carve corner tracks in one pass by designating the track carving twice and canceling unwanted carvings (with {{K|d}} {{K|x}}). Tracks can be engraved in any natural floor tile, rough, smooth and even over engravings, providing an easy method to remove low-quality or undesired floor engravings. Once a track has been engraved, it's important to check the track directions for each tile in the route carefully to make sure no mistakes were made by yourself or the game's track engraving logic.

'''Constructed'''

Tracks can also be built as regular [[construction]]s (through {{K|b}} {{K|C}} {{K|T}}). This method is resource-expensive, since each track tile requires one stone, [[bar]], or [[block]] for construction, and time-consuming, since you can't designate strips longer than 10 tiles at a time. Corners, crossings, T-junctions, and ramps also have to be designated individually. However, it is usually the only way to build tracks above ground or on soil (barring the [[Obsidian farming|creation of obsidian]]). Constructed tracks are designated for removal like any regular construction; be aware that removing track ramps built on top of natural ones will also remove the original ramp, leaving a flat floor.

====Ramps====

'''Carved'''

The carving of natural ramps is a little more confusing: to carve a two-way track on a ramp (natural only, does not work on constructed ramps), you must designate the track '''starting on the ramp and one square beyond''' in the direction you want the track to go. For the side of the ramp square you want to head upward, there '''must''' be either a natural or constructed wall in the square next to it, otherwise the game assumes you are trying to carve it on the same level -- this can result in the track being carved underneath a door or other object. If you have accidentally done this, you can correct it by smoothing the ramp and constructing a single square of wall next to it, then re-carving the ramp correctly. (However, the wall must stay there permanently; removing it will disconnect the track.)

'''Constructed'''

When constructing track ramps, the stated direction should be the same as the connected tracks. For example, a track going up from West to East would require, starting from the West, a Track (EW), a Track/Ramp (EW) and a Wall behind the ramp, underneath the section of track above it. Incorrectly placed ramps result in minecarts ignoring the ramp and crashing into the supporting wall. They will not, however, display as unusable as when the supporting wall is missing.

'''Examples of ramps'''

A simple ramp would look like this:
{{diagram|spaces=yes|\
z +0 z +1
░░░░ ░░░░
═▲o ░▼═
░░░░ ░░░░
o : wall
}}

Carving track corners into ramps is rather unintuitive and complicated. Since engraving tracks always requires two tiles to connect in a straight line as input, you have to give two separate designations for a single job: a track bit from the ramp tile to the "below" direction and another one to the wall of the "upward" direction. If you wanted to change direction on a ramp from east to north:
{{diagram|spaces=yes|\
z +0 z +1
░░░░░ ░░░░░
░░░░░ ══╗░░
=▲░░ ░░▼░░
░░░░░ ░░░░░
}}
you would need to connect the ramp on z +0 both to the west and to the north by issuing two "carve track" commands, one selecting the ramp and the track tile to the west, and another connecting the ramp tile with the wall to the north. An engraver would then carve a NW track corner into the ramp, allowing carts to pass the corner correctly both going up and down. Such track corners are perfectly serviceable for guided carts, but moving down a route of several of them by pushed or ridden cart is problematic - ramps on corners behave very counter-intuitively, resulting in loss of speed when going down and diagonal movement when going up.

Moving to and from ramps (or between ramps "pointing" in different directions0 causes some non-trivial adjustments to speed and even moving along the tiles at a fixed speed ''unrelated to the entry/exit velocity values'', because transitions to/from ramps are processed differently and are not to be "skipped". This affects compact track/ramp combinations (such as e.g. a simple 2x2 ramp spiral) most, and combined with bouncing often makes them work not in the way one could expect. {{cite forum|144328/5705102}}

{{anchor|Tracks}}

=== Hauling route ===
A hauling route is a list of directions describing how and under what conditions a minecart will move. The proper setting up of routes is essential for a working rail system. Routes, stops, departure conditions and stockpile links are managed from the {{k|h}}auling menu.

==== Route ====
A route defines the path a minecart will take along a track, as well as under what conditions it will move or stop moving. A route is made up of stops. Stops are precisely what they sound like, a position on the track at which you want a minecart to stop. A minecart track might use as little as a single stop for a looped track, which will serve as both a starting and stopping point for the cart, or it could contain many stops, perhaps to load supplies or wait for a bridge to be manually lowered, before reaching its destination or returning to its starting point. It is important to note that you only need to place stops on a route where you actually want the cart to stop and wait for some action to occur. They are not needed to help navigate the cart along the track beyond telling it where on the track to stop.

New routes are created with the {{k|h}}auling key. Existing ones can be removed (without confirmation) with the {{k|x}} key, and also {{k|n}}icknamed. Before operating, the route must have a {{k|v}}ehicle assigned to it (this can be done with either the route or a stop selected). Assigning a full minecart to a route may result in a slow hauling job if the contents are heavy.

==== Stops ====
Stops are the individual waypoints that make up a hauling route. A given stop consists of the location of a tile, as well as conditions describing when, where, and how a cart should be moved after being stopped at that tile. Stops can be created from within the {{k|h}}auling menu, by placing the cursor over a tile and hitting {{k|s}} while highlighting the route (or a stop within) you've already designated. A minecart will begin its route at the first stop created, and continue through each subsequent stop, being guided, pushed, or ridden from each stop to the next depending on the conditions specified. In many basic minecart applications, the cart will end up at the same stop it began at, though this is not always the case. It is important to note that hauling stop order is enforced, even if there is no track. A dwarf will drag the cart overland back to a skipped stop in the route's list if your tracks bypass it somehow.

Once a stop has been placed, it is given a default set of conditions under which to move the minecart if it is stopped there. Each new stop gets the same default conditions regardless of the track it is placed upon (e.g. guide the cart to the north). For this reason new stops might get marked by yellow exclamation marks ({{DFtext|!|#ff0}}) due to invalid directions. One important thing to note is that as you place additional stops, the display will show paths between the stops you have defined. However, this is '''not''' necessarily the actual route the minecart will take once the route is in operation. For example, if a route were defined with two stops at opposite ends of a track with many twists and turns, a line will be drawn directly between those stops to show the order in which they will be visited. These route lines may crisscross all over the tracks, but so long as the track is valid end to end, the cart will follow the track from one stop to the next, even across twists, turns, and z-level changes. Stops, which are the steps that make up a route, should not be confused with Track Stops, described below.

===== Stockpile links =====
By placing the cursor on top of a stockpile and using {{k|s}}, you can create stockpile links while defining a hauling stop. Links can also be redefined by selecting them, placing the cursor over a different stockpile, and pressing {{k|p}}. The cart will then be filled by items present in its various linked stockpiles in preference to other items. Note that bins should be used with caution in stockpiles that are linked to minecarts. Bins cause problems when used with the "Desired Items" list in a stop's conditions. For example, if a minecart is set to accept only granite blocks, and to depart north when it is 100% full of granite blocks, it will not depart if any of those granite blocks are in bins, even if bins are also included in the desired items list. Two solutions to this problem exist as of v0.40.24. First, bins can be disallowed in stockpiles that are linked to stops. Alternatively, bins '''can''' be used in conjunction with minecarts provided that the minecart's departure conditions use only "any items" instead of "desired items." This option can be toggled in the advanced conditions menu for a stop, accessible via the {{key|C|}} key. The cart's contents can still be controlled by specifying what items are allowed in the linked stockpile.

===== Departure condition =====
Departure conditions involve setting conditions in which the minecart will leave on the route. Each condition includes:
# A departure mode (Guide, Ride or Push).
# An initial departure direction (NSEW). Note that this defines the initial direction of movement only. Even if a track includes many turns, as long as the initial movement direction is valid the cart will follow the minecart track thereafter.
# A timer, before which the departure condition cannot be met.
# Conditions on the amount of items in the cart.
Departure conditions are created with the {{k|n}} key. A new departure condition will read: "guide north immediately when empty of desired items". This condition can be changed between basic presets with {{k|c}}. "Advanced" mode ({{k|C}}) allows for more precise control over departure conditions: fine tuning the percentage from 0 to 100 in 25% steps ({{k|f}} and {{k|F}}), switching it being either the maximum or the minimum amount of items for the condition to be met ({{k|m}}), and whether the cart accepts all or only a specific set of items ({{k|l}}). Common to both screens are the departure mode ({{k|p}}, Push, Ride or Guide), {{k|d}}irection, and timer ({{k|t}} and {{k|T}}) options.

To have a cart only carry a specific set of items, the stop can be set to only carry "desired" items, opening the selection screen with the {{k|Enter}} key while having said stop condition selected, and toggling as desired, or it can simply be linked to a stockpile and set to depart once it is full of items from its linked stockpiles, regardless of type.

=== Track Stops ===
A Track Stop, not to be confused with a route stop, is an optional, single-tile construction which serves two purposes. First, it can be used to cancel a cart's momentum in order to slow or stop it as it passes over the Track Stop. This might be necessary if a cart were pushed down a series of ramps to its destination. Second, a Track Stop can cause a cart to automatically dump its contents as it passes over the Track Stop. Track Stops are constructed via {{k|b}} {{k|C}} {{k|S}}, and must be constructed atop an existing piece of track. If a Track Stop has been set to automatically dump a cart's contents, the cart will dump its contents in the direction indicated when it passes over the Track Stop. Depending on the friction settings chosen for the Track Stop, the cart might then stop after dumping, or it might continue on its route to another destination.

Track Stops are not mandatory; in fact, their main use is in automated rail systems. However, even in basic rail systems it can be useful to set a Track Stop to dump items: this saves time that dwarves would otherwise spend in removing items from the cart, time that is better spent driving the cart back to where it's needed. Dumping will occur even with a guided cart. '''Take care not to set Track Stops at a loading site to dump their contents''', or dwarves will never be able to fill the cart. It will dump any contents the moment they are loaded.

Counter-intuitive to their construction method, Track Stops are considered [[building]]s and must be removed by {{k|q}} {{k|x}}.
* See [[#More_on_Track_stop |More on Track Stops]]

=== Step-by-step tutorial ===

Let's construct a simple minecart route. This route will move stone blocks from an input stockpile to an output stockpile. We'll begin by creating the stockpiles:

[[File:minecart-example-1.png|Stockpiles designated.]]

The input stockpile is on the left; the output stockpile is on the right. We'll be moving blocks from left to right. Disable bins in both stockpiles, and set the input stockpile to accept only from links. Then make the stockpile take from the mason's workshop where the blocks are being produced.

Next, carve the track:

[[File:minecart-example-2.png|Track carving designation.]]

Note that the ends of the designation are uniquely shaped; this is automatic, and not anything you need to control. Now, wait for your engravers to come along and carve the track into the stone. (Your haulers will probably also fill up the input stockpile while you wait.)

In addition, while we're waiting for that to happen, we'll build an iron minecart in the forge.

[[File:minecart-example-3.png|Track carved.]]

When the track has been carved, it will look like the above (the track will be solid instead of flashing). Now, order a track stop to be constructed next to the output stockpile:

{|
| [[File:minecart-example-4.png|Track stop designation.]]
| [[File:minecart-example-5.png|Select dumping direction.]]
|}

You must press {{k|d}} three times to select the dumping direction ''before'' placing the track stop. We want our blocks to be dumped into the output stockpile east of the track stop. Then wait for a mechanic to come along and build the track stop.

[[File:minecart-example-6.png|Track stop constructed.]]

Now we'll define the actual ''route''. This is done in the {{k|h}}auling menu. Press {{k|r}} to begin defining a route. Next, move the cursor to the input end of the track, and then press {{k|s}} to define the first stop:

{|
| [[File:minecart-example-7.png|Stop 1 designation.]]
| [[File:minecart-example-8.png|Route definition, in progress.]]
|}

Move the cursor again, to the output end of the track, and press {{k|s}} again to define the second stop:

{|
| [[File:minecart-example-9.png|Stop 2 designation.]]
| [[File:minecart-example-10.png|Route definition, two stops.]]
|-
|
| [[File:minecart-example-11.png|Stops are not defined yet.]]
|}

There are several user interface features to note at this point. The stops have been positioned, but they haven't been ''defined'' yet, so there is a warning {{DFtext|!|#ff0}} symbol by each of them. In the lower right corner, we see what the {{DFtext|!|#ff0}} means. Also, note that the second stop is labeled in white, while the other two lines are grey. The white text is a selection indicator, and can be moved up and down by pressing {{k|+}}/{{k|-}}.

Next we need to define what our stops do. We want the minecart to be filled with blocks at the first stop, then travel to the second stop where it will dump its cargo, and then return. Press {{k|-}} to move the selection up to stop 1, and {{k|Enter}} to open it up. By default, the stop has three conditions:

[[File:minecart-example-12.png|Default stop definition.]]

We don't want any of these, so press {{k|x}} three times to delete them. This leaves us with a blank stop. Now we can add the conditions we actually want. Press {{k|n}} to begin adding the first condition, then {{k|d}} twice to change the direction from north to east. Then press {{k|c}} to change the condition from empty to full. This will instruct the minecart to be guided east when full of desired items.

To set the desired items, we create a stockpile link. Press {{k|s}}, then move the cursor to the input stockpile, then press {{k|p}} to select that stockpile. Now press {{k|Enter}}; this opens up a selection screen that resembles the stockpile customization screen. Move down to Blocks, {{k|e}}nable them, then (if you wish) restrict it to stone blocks.

When you've done all that, stop 1 should look like this:

[[File:minecart-example-13.png|Stop 1, defined.]]

Stop 2 is much simpler. All we need to do is have the minecart return to the input stop. So, make a condition and change the direction:

[[File:minecart-example-14.png|Stop 2, defined.]]

Finally, we just have to assign our minecart. Go back to the route definition screen, and press {{k|v}}. Select the minecart, and press {{k|Enter}}.

Now we've got everything set up:

[[File:minecart-example-15.png|Route, fully defined.]]

The V is red because the minecart hasn't been moved onto the track yet. Some dwarf will have to haul it from the forge to the first stop, by hand; this will take a while, especially if the forge is far away.

Once the minecart is in place, dwarves should fill it with blocks from the input stockpile, which will in turn be filled with blocks from the workshop where your mason has been toiling dutifully. When the minecart is full, the blocks will be dumped into the 1x1 stockpile on the right. Automatic quantum dumping!

=== Troubleshooting ===

Because of the complexity of the system, all but the most careful and experienced minecart users will encounter issues. Most route issues can be diagnosed and fixed from the {{k|h}}auling menu.

'''Symptom:''' {{DFtext|! Set dir/connect track|6:1}} message appears to the right of one or more stops

'''Possible Causes:'''
* The departure direction of the stop might be invalid. Edit the stop using {{k|Enter}} and press{{k|d}} until it is pointing in a valid direction.
* The track stop might not be built on top of a track. The track stop must be deconstructed to remedy this issue.
* Your track might not be built correctly. Make sure all connected tracks between destinations are not one-way tracks.
** This can be especially confusing with ramps. To carve a two-way track on a (natural) ramp, you must designate the ramp and one square beyond in the direction you want the track to go.
** Ramps '''must''' have a solid block on the side opposite to the track, or they will neither work nor be marked as "unusable". The solid block can be natural or constructed.
* The desired/kept items might not be configured correctly.

'''Symptom:''' The status '''0% V''' always appears to the right of one stop.

'''Possible Causes:'''
* The stop may not be set to take from a stockpile. Edit the Stop using {{k|Enter}} and make sure you see a message like "Take from Stockpile #1".
* The take conditions must correspond with the contents of the stockpile.
* The track stop may be set to dump. A track stop set to dump cannot be filled. You must either set the stop to a time-based departure or deconstruct the track stop and rebuild it without dumping. (Alternatively, with [[DFHack]] you can modify "Dump on arrival" to "No" using the {{key|q}} menu without rebuilding the stop.)
* Make sure the minecart itself has not been designated to be dumped (such as when using mass-dump).

'''Symptom:''' Dwarves fill the minecart properly, but will not move it thereafter.

'''Possible Causes:'''
* The minecart may contain items which are not included in its current stop's desired items. Check inside the minecart using the {{key|k}} and {{key|z}} keys and ensure that all items in the cart are desired items.
* The minecart may contain desired items in bins. Minecarts seem to have problems realizing that they are in fact full of desired items if some of those items are in bins, even if bins are also among the desired items for that stop. '''This cannot be solved by adding the appropriate bins to the stop's desired items.''' Either disallow bins in stockpiles you intend to load minecarts from, or set the departure conditions to rely only on percentage of total load rather than percentage of desired items using the advanced conditions menu ({{key|C}} key).

'''Symptom:''' Dwarves repeatedly attempt to load the minecart, but no items are ever loaded into it.

'''Possible Causes:'''
* This can be caused by using a Track Stop with autodumping enabled at a loading site. Every time a dwarf places an item into a cart resting on such a track stop, the item will be immediately dumped, causing unlimited, useless cart loading jobs. Autodumping Track Stops should never be used at a loading site.

'''Symptom:''' A dwarf picks up the minecart and carries it to its destination.
* See [[#Quirks|Quirks]]

=== Danger ===
Minecarts are not without <strike>danger</strike> [[fun]]. Although designating a track automatically sets the [[traffic]] designation to low, dwarves ''may'' still walk on them, and [[creature]]s ignore traffic designations altogether. If an unlucky dwarf or creature fails to [[dodger|dodge]] a minecart, they can be injured. Most of this danger can be avoided by setting the minecart {{k|h}}auling commands to guide instead of push or ride (dwarves guiding minecarts will ignore traffic restrictions), as well as by [[pasture|pasturing]] domestic animals and preventing the access of other creatures to the tracks. Note that removing the track doesn't reset that tile back to normal traffic priority, so you may wish to manually clean up traffic designation afterward. Also note that bridges that are used as tracks don't have their traffic priority changed automatically (since they're just normal bridges), which could cause dwarves to pathfind normally through dangerous minecart entrances in your fort's walls if you're not careful.

The only <s>fool</s>''dwarf''-proof method is to make the tracks inaccessible. There are several ways to create a track which works for minecarts but doesn't allow creature-traversal; the simplest is perhaps building a [[statue]] on the tracks. Other options include adding single-tile holes (minecarts moving at reasonable speed will jump the gap), vertical drops, minecart-triggered doors, small pools of liquid (4/7 water or 2/7 magma), and hostile creatures overlooking the tracks. For safety, both ends of the track should be isolated, making the dangerous center sections completely inaccessible (though maintenance access can be provided by a locked door).

Danger does not always involve living victims: careless route designation can also result in minecarts careening off tracks or colliding with each other. If this occurs, the [[item]]s may be scattered; this can cause even more hauling jobs than the minecart aimed to eliminate. Even <s>better</s> worse, scattered items, especially [[weapon]]s, can injure passing [[dwarf|dwarves]] or other [[creature]]s; in the words of Toady One the Great, "Accidental grapeshotting of the dining room should be possible now."

Of course, the danger of using minecarts means they can also be [[Trap_design#Minecarts|used as weapons]] by imaginative players.

== Advanced usage and automation ==
Minecart-specific effects are implemented via track stops, rollers and [[pressure plate]]s with "track" condition set. Since all three are considered [[building]]s, they can't be built on the same square (however convenient track stop + pressure plate would be) nor a simple ramp, and are removed by {{k|q}} {{k|x}}.

=== More on Track stop ===
Track stops are constructions that allow further automation of minecart systems via adjustable features such as braking by friction and automatic dumping of contents. They can be built from logs, bars and blocks through {{K|b}} {{K|C}} {{K|S}}; friction amount, dumping toggle and dumping direction must be set '''before''' construction, and these settings can be neither changed nor seen thereafter; however, track stops can be linked to [[pressure plate]]s or [[lever]]s to toggle friction and dumping On or Off (trigger state is inverted: switch On = track stop Off).

If a [[stockpile]] is placed on the tile that a track stop is set to dump to, it can act as a [[Exploit#Quantum_stockpiles|quantum stockpile]] and any items dumped from a minecart that match the storage settings of the stockpile will remain there and accumulate. Normally trackstops are built on top of existing track to operate on moving minecarts, but they can also be used without tracks to create [[Exploit#The_Minecart_Stop|automatic quantum stockpiles]] (see also [[#Step-by-step_tutorial|step-by-step tutorial]]). It is not always desirable to collect ALL of certain items into one quantum stockpile, such as when distributing a material to multiple separate industries. You can link your quantum stockpile to various other stockpiles, ensuring that your dwarves will keep them supplied as necessary. Because quantum stockpiles never fill up like regular stockpiles, it may be a good idea to add a switch to turn them off.

Items dumped from a minecart at a track stop (or dumped by any other means) into open space fall through z-levels until they land on a solid surface. Items falling onto a designated [[stockpile]] will automatically be considered part of that stockpile, even if the stockpile is set to disallow those items (they will, however, be automatically moved to a more appropriate stockpile, if available). Items falling on top of a minecart will '''not''' fall "inside" the minecart. Use with caution; dwarves have fragile skulls.{{bug|5945}}

=== Automated propulsion ===
==== Roller ====
{{Main|Roller}}

A '''roller''' is a [[power]]ed [[machine component]] for the automated propulsion of minecarts. They are built over the top of existing tracks with {{K|b|M|r}}, requiring a [[mechanic]], ''(length/4)+1'' [[mechanism]]s and a [[rope]]. Rollers may also be placed directly on ramps to help pull carts up Z levels. Rollers are very useful to maintain a cart's momentum along long routes, to get them to climb Z-levels without dwarfpower involved, and to get them to reach speeds unattainable by guiding dwarves. These devices are variable-length (1-10), variable-direction and variable-speed ([[Minecart#Numbers_behind_the_scene|see below]]), all traits that can be set at construction time; a roller uses two units of power per tile it is long.

Single-tile rollers transfer power in all four cardinal directions, while other rollers generally only transfer power perpendicular to their activity direction. Longer rollers can also transfer power along their activity direction if built in the correct order, although this can be hard to accomplish and is easily broken. Rollers cannot be powered from above.

Rollers have great acceleration and capped speed. Carts going faster than the roller are unaffected. If a cart moves across an active roller in the direction the roller works and moves slower than the roller's specified speed, the cart will be set to the roller's speed. A cart going against a roller's movement direction will be sent back the way it came (once again at the roller's speed), unless it was moving extremely fast: speed increment of 100000 allows to reverse carts from the full "highest" (50000) speed roller to full "highest" speed back, but ramps can accelerate a cart beyond this. {{cite forum|144328/5702453}}
A cart crossing over a roller perpendicular to its current movement direction will gain the roller's amount of speed in the perpendicular direction without directly changing its forward motion. Without an adjacent wall to constrict its movement, this will typically send a cart off the rails on a diagonal path, completely unable to follow any tracks until it collides with a wall or is otherwise brought to rest. However, if the roller is placed over a track turn and pushes ''from'' the direction of that turn's track, the turn affects carts ''after'' the roller, so they will be forced into the turn rather than derailed in a diagonal direction. {{cite forum|144328/5702453}}

{{diagram|spaces=yes|\
tracks: full:
║ ║
═╗═ ═╢═
║ ║

╢ : roller pushing from W to E
}}
If the roller is powered, carts from ''all'' directions (unless too fast) exit S, because speed imparted by the roller forces carts toward E and ''then'' into the turn.
If not powered, carts from W and N exit S, carts from E and S exit W. Carts above derail speed will ignore the turn, of course.

{{diagram|spaces=yes|\
║ ║
═╗═ ═╟═
║ ║

╟ : Roller pushing from E to W
}}
Carts from the E or W: exit W.
Carts from N: derailed diagonally, exit SW.
Carts from S: derailed diagonally, exit NW.

Rollers affects carts on a track - if placed on a floor or ramp without any tracks, they are ignored. Depowered rollers are also ignored, friction is determined by the tiles underneath.

Because of their one-way nature, rollers are unsuitable for most two-way minecart tracks (unless you set gears toggling roller A->B off while toggling A<-B rollers on). However, a minecart set to be ''guided'' is not affected by rollers at all{{cite forum|109460/3286235}} — this allows a one-way track to be used in both directions. In addition, unpowered rollers do not affect minecarts.

Care must be taken in [[glacier]]s and other extremely cold [[biome]]s, since rollers (and the machinery used to power them) will not operate when constructed on natural [[ice]] floors.

==== Impulse ramps ====
Carts can be given momentum without rollers or changing z-level through a phenomenon called "impulse ramps". A track ramp which is connected both to a wall and to a floor will ''always'' accelerate a cart towards the connected floor tile, no matter where the cart enters the tile from. This means carts can be accelerated as though dropping z-levels, even if the cart doesn't actually change z-level at all. If a track ramp faces three directions such as ╩, then two of those directions need to be facing walls for the cart to be accelerated towards the remaining direction.

Example of straight impulse acceleration:

{{diagram|spaces=yes|\
▒▒▒▒▒▒▒▒▒▒ ▒▒▒▒▒▒▒▒▒▒
═▲▲▲▲▲▲▲▲▲▲═ ═╚╚╚╚╚╚╚╚╚╚═
▒ : Wall
═ : Normal track
▲/╚ : N/E Track/Ramp
}}

If a cart enters from the left, it will speed up on every track/ramp and exit to the right going very very fast - more than one tile every step. If it enters from the right then it will bounce back impulsed by the ramp if it's going slow enough.

As another oddity, carts coming from ramps will in some cases "teleport" through most of the next tile. This can be used to send carts up levels with minimal loss of speed. You can just make an upward spiral alternating impulse ramps and regular upward ramps. It takes no power, is quick and cheap to build, requiring only channeling and track carving, and the cart goes up fast, but not so fast that it launches its contents.

Example of an impulse elevator:

{{diagram|spaces=yes|\
z +0 z +1 z +2 z +3
░░░░░ ░░░░░ ░░░░░ ░░░░░
░╔░░░ ░▼╚╗░ ░░▼▼░ ░░░░░
░╝░░░ ░▼░░░ ░░░╔░ ░░░▼░
░▼▼░░ ░░░░░ ░░░╝░ ░╚╗▼░
░░░░░ ░░░░░ ░░░░░ ░░░░░

░ : Wall
╔,╚,╗,╝ : Track/Ramp
▼ : Down Ramp (empty space)
}}

A sort of opposite effect to impulse ramps also exists: ramps lacking the proper "up" and "down" connections are treated as flat track, even if they actually go up or down z-levels. This allows building "anti-impulse" slopes consisting entirely of ramps only connected up, which a minecart can travel up forty levels and more, needing no more than a single push.

=== Controlling traffic ===

==== Switching ====

As constructions or tile features, [[door]]s and other furniture can be built on tracks. A [[door]] or [[floodgate]] can be turned on or off by a [[lever]], effectively controlling the flow of automated minecarts. This may be <s>dangerous</s> [[fun]], however.
{{diagram|spaces=yes|\
->
A ════┤≡════ B
┤ : roller pushing to East
≡ : door
}}
The roller pushes the cart east, but until the "departure condition" is fulfilled, the door remains closed and blocks the path.

[[Bridge]]s can also act as tracks, but only if they're lowered or not retracted. This property can enable levers to turn tracks on and off. However, care should be taken to ensure that such bridges are never operated while a cart is on top of them, as the cart will be flung off the track. It's worth noting that it's often faster, and cheaper, to construct large bridges than long sections of constructed track.

A powered track switch can be constructed by building an "inverted" corner as illustrated below.
{{diagram|spaces=yes|\
B B
║ -> ║
║ ║
════╚═══ ════├════
A C A C
├ : roller pushing to West.
}}

If the cart is pushed East from the stop at 'A' while the roller is activated, it will arrive at 'B'. If the roller is not running, it will arrive at 'C'. The switch works by the roller first reversing the incoming cart's movement and the cart ''then'' following the track corner.

This switch is very reliable, reacts instantly to on/off signals, and carts of any speed can be switched by this design, although very fast carts will require rollers that are several tiles long, up to three. The requirement for power can be inconvenient or impractical. Non-powered solutions may use controlled derailment, or a connecting bridge.
{{diagram|spaces=yes|\
B ╥
║
║
╞════╝ ════╡
A D C
}}
Here the track between A and C is not continuous. The only continuous track is A->B, with a corner (not a T section). Fast moving carts will tend to derail at D and rejoin the track to C. Placing a door at D will prevent the derailment, so the cart continues to B. The door is operated by mechanisms elsewhere (typically, a lever, but some fun can be had with pressure plates).

Since it depends on derailing, this switch requires a very fast cart, faster than what can be achieved with rollers alone. To gain sufficient speed, a cart must be accelerated further, usually by descending several levels or through impulse ramps. The high speed makes the cart much more dangerous and harder to control.

If carts are moving too slowly to derail at the corner, a retractable bridge may be used as a connector between A and C.
{{diagram|spaces=yes|\
B╥
║
║
A╞════bbb════╡C
}}
The bridge must overlap the corner. Bridges behave like a track crossing, allowing carts to pass in a straight line. When retracted, the corner reappears, so the carts will continue to B. Bridges take 100 steps to react to a signal, necessitating rather long "lead times" when switching tracks via bridge.

As mentioned above, special care must be taken to make sure the bridge doesn't change state while the cart is passing over it. Retracting bridges will throw the cart, causing it to stop dead. Raising bridges can even crush the cart.

==== Controlling Speed ====


Minecarts can reach extremely high speeds, especially when descending multiple Z-levels. A minecart will derail at a track corner if its speed exceeds 0.5 t/st (tiles per step), '''unless''' the route in the direction of travel is blocked:

Will derail at > 0.5 t/st:

{{diagram|spaces=yes|\
in ══╗ -> derailing
║
out
}}

Will not derail at > 0.5 t/st:
{{diagram|spaces=yes|\
in ══╗O
║
out

O : wall/column.
}}

This behavior can be used to build a "speed limiter", that will ensure that when a minecart exits it is traveling below derail speed:
{{diagram|spaces=yes|\
░░░░ ░░░░░ ░░░░░
in ═╔═╗░ ░╔S╗░ ░╔S╗░
out ═╬═╝░ out ═╗═╝░ out ═╗═╝░
░╚S╝░ ░╚═╝═ in ░╚S╝░
░░░░░ ░░░░ ║░░░
in
░ : wall
S : Track Stop (High Friction or lower)
}}
If the minecart is traveling below derailment speed, it will not be affected; if above, will be slowed down and checked again. Granted, you could do the same just with track turns, but it may take a lot of turns and time.

Since all the derailings, bounces and ramps can impart a sideway component of speed small enough to start visible drift many tiles away (say, [[Fun|in the middle of a bridge]]), track turns have one more use: forcing the carts to move strictly along the grid directions. Carts passing a turn below derailing speed convert one component of velocity into another, thus eliminating the drift.

=== Loading liquids ===
[[Water]] and [[magma]] can also be loaded into minecarts by submerging them to a depth of at least 6/7 while standing still or moving at speeds of at most 10000. Loading fluids onto minecarts can be difficult because the added friction provided by fluids can stop a cart in a submerged tile. Curiously, filling a minecart with magma does not injure a dwarf ''riding'' it. A minecart will hold enough fluid to increase the depth of a single tile by 2. This amount is listed as 833 units, which weigh 459Γ (water) or 999Γ (magma). An iron or steel cart filled with magma weighs 1313Γ, while an adamantine cart filled with magma weighs 1007Γ. Since you need a minecart above the liquid's level, possible arrangements may include pressure-activated sluices, rollers (with magma-safe chains for magma), pouring from above to "submerge" it briefly on the same level and drain excess away (dig deeper and leave a vaporizer, though if you could have power for rollers, may as well use a pump) and exploits with ramps (not necessarily impulse ramps, "same height" passing dip does it).
The liquids can be dumped by a constructed track stop.

== Quirks ==
This little quirk concerns dwarf-managed minecarts. If a track which was previously open becomes blocked (ex. flipping a switch connected to a floodgate you've built on the track to raise it) and the conditions for departure are met, instead of refusing to ride/guide the minecart or ride/guide it until it reaches the obstacle, the dwarf will pick up the minecart off the tracks and haul it to its scheduled destination on foot. If the distance is long enough and the weight of the cart heavy enough (due to being filled with heavy items such as stones), the dwarf may drop the cart because of fatigue/hunger/thirst before reaching the destination. This will cancel that vehicle setting job and make another dwarf come by and attempt to haul the cart to the nearest appropriate stockpile where another dwarf will pick up the cart and attempt to haul it to its initial stop. If the stockpile is far enough from initial stop, this second dwarf who is attempting to place the minecart on its tracks may also drop the minecart out of fatigue/hunger/thirst creating a loop that will go on until a dwarf with enough endurance manages to place the minecart where it belongs.

In fact, it seems dwarves are more than happy to attempt to carry a minecart from one stop to another even if just waiting until the track is open again would be the more sane option.

Dwarves will also carry a minecart to its next stop if the direction specified is incorrect (or invalid). This can often occur when using the default departure settings and forgetting to set the direction of each condition.

Dwarves can admire buildings while riding mine carts. Dwarves will not fall asleep during a ride (at least not from being drowsy). If riding on a continuous powered track loop, the dwarf will die of dehydration/starvation as they can not jump off to get sustenance{{cite forum|109460/3377228}}. Dwarves riding in submerged minecarts will gain experience in [[swimming]].{{cite forum|129889}}

Tracks block wagon access to trade depots, unless they're on a ramp. [[Bridge]]s can also be used, as they function as tracks but do not block wagons.

== Physics ==


Minecart physics depend greatly on the departure mode set in the route stop conditions.

When set to "Push" or "Ride", minecarts will move according to the regular laws of momentum, gaining speed when going downhill, losing it slowly due to friction when on a flat plane, and more quickly when going uphill. In these modes, minecarts will move in a straight line until they either are brought to a stop by friction or an obstacle, or until they encounter a turn. A minecart will roll straight past "blocked" ends of T-junctions or track ends, they have no power to restrict a cart's movement. The cart's behavior is largely independent of the weight of its contents (including fluids and dwarves): heavily loaded carts gain more momentum when accelerating, but this only plays a role in collisions: a heavy cart gains just as much speed and is as easy to stop as a light one. In either case, dwarves can not push nor ride an unpowered cart up a ramp, bouncing back the direction it came. At best, this is a waste of time; at worst, it will give your cart-pushing dwarf a [[fun|fun surprise]]. To solve this, the player can either use Rollers (see below) or set the cart to be Guided.

The difference between "Push" and "Ride" is whether the dwarf will go along with the cart or not.
{{DFtext|Push}}: the dwarf will give the cart an initial push, not enough to go up a ramp, but enough to go some way along flat track, and the dwarf will remain at the first stop, ready for a new job.
{{DFtext|Ride}}: the dwarf will give the cart the same initial push and then hop aboard the cart riding with it to the next stop.
{{DFtext|Guide}}: minecarts seem to ignore all laws of physics. That is:
*Ignore the weight of any and all items inside. Therefore:
**Move at the speed of the dwarf that is guiding them. It is thus recommended to pick the most [[attribute#Agility|agile]] of your dwarves for cart-guiding tasks.
*Ignore working rollers.
*Will ''not'' collide with other guided carts even when a full frontal collision would be expected.
*Will go up ramps like nobody's business.
This is therefore the recommended method of transport for simple non-powered rail systems, despite it diverting a dwarf from other, potentially more important tasks.

Some samples with behavior:
{{diagram|spaces=yes|\
A <-> B A <-> C A <-> B
B B B
║ ║ ║
A══╝ A══╩══C A══╬╗
You can only go A->B ╚╝
Works when the cart Works
is in Guide mode.
}}
In the second example above, a cart "pushed" from B will go over the junction and roll off into the unknown south.

=== Track Direction Irrelevance ===
Carts that are traveling independently, (that is, not guided,) only care that tracks ''are'' on the tile, not which direction the tracks actually move. Tracks respect only curves (with two exits) and ramps.

This means, for example, that the following tracks, when a (non-guided) cart travels from West-to-East, are functionally identical in effect:

A════════════B A╬║╚╔╣╩╦╠╥╨╞╡B

This is because so far as the cart is concerned, only ramps and curves with two exits where the exit in the path they are traveling matters.

Carts only check for curves when they are halfway through a tile. When they get there, they look to see if their path has no exit. (That is, if it is traveling East, it checks if there is an East exit.) If there is, it ignores all other track directions, and keeps traveling. If there is not, it checks to see if there are only two exits to the track, and if one of those directions was the direction it "came from". (That is, if traveling from the East, it checks if there is a valid exit to the West, and if so, if there is either a North exit or a South exit.) If there is not, it ignores the track anyway, and keeps on traveling as though it were still on track. If there is, it will subtract 1000 from the velocity of the cart, and redirect all forward velocity to the direction of the curve. This change in the direction of velocity ''overwrites'' any "diagonal" velocity, which can prevent diagonal velocity derailments, but any perpendicular velocity is not preserved, and is instead discarded.

=== Invalid Ramps ===
Ramps are functionally defined for cart purposes as being a tile which exerts an acceleration force upon its "downward slope". This downward slope requires a cart to have one ''and exactly one'' carved exit to the tile that is the "bottom" of the ramp. Ramps push carts in this "downward" direction (possibly leading to diagonal movement, below), and the deceleration of an "uphill" ramp is actually just the acceleration being applied against the direction of a cart's movement.

This is where players can find an exploit in the behavior of ramps - if there are ''two'' "downhill" exits to a ramp (such as a "T junction" on a ramp where only one exit faces a wall), then the ramp provides no acceleration ''or'' deceleration, allowing carts to travel up ramps without any loss of momentum except for the standard "flat track" deceleration, because as far as the cart is concerned, the track ''is'' flat.

Similar effects can be achieved when there are ''no'' "downhill" exits to a ramp. This may be the case if you have, for example, an East-West track with a one-tile channel with a ramp in it. The cart will travel through the "dip" with no change in velocity. It can also be the case if you abuse the Track Direction Irrelevance, above, and set only exits ''up'' the ramp, and none leading ''down'' the ramp. For example, if a cart is traveling from West to East up a slope, only carving East exits on each tile of ramp will make the cart travel up the ramp, and then recognize the tile it is on as being a "flat" tile, thus ignoring any deceleration from traveling uphill. Note that this effect only reliably occurs at relatively slow speeds (at around push, or single accelerating ramp speeds) as the cart may simply ignore the ramp and crash into the wall at higher speeds.

=== Skipping ===
If a minecart is moving fast enough, it can skip over [[water]] or [[magma]], making splashes of [[mist]] (or [[magma mist]]) as it attempts to move on them horizontally. This horizontal movement is independent of the minecart and its content's [[weight]].

=== Track Jumping ===
If a minecart encounters the end of the track or a T junction with no "exit" in its movement direction, it will simply leave the track and continue on its course in a straight line until it encounters an obstacle, slows to a stop, or encounters another (properly aligned) Track even if the tile at which it joins the new track instantly sends it around a corner.

Tracks that are travelling at high enough velocity will also start "jumping" the track if it hits an un-tracked tile (flying over and ignoring any tracks) until it is ready to land. Carts that land upon tracked tiles re-rail themselves, and clever designers use this feature to jump over curved track sections in one direction or another. (Retracting bridges over untracked tiles can cause jumps or not cause jumps depending upon the status of the bridge.) Minecart speed must be carefully regulated to ensure reliability of jump length.

Carts that approach a downward slope at a high enough velocity will also make a jump, but will not do so if the Checkpoint Effect (below) is exploited through an impulse ramp before the actual downhill as the impulse ramp "tricks" the cart into thinking it has already started going downhill.

=== Corner Ramp Derail ===

Corners on upward ramps can cause diagonal movement, forcing a derail even if the cart has a wall next to it, which will force a stop when it touches a wall that forces dwarves to manually reset the cart.

This is caused by the fact that a cart, after turning the bend in the track halfway through the length of the tile, will still "accelerate down", which is now perpendicular to the movement of the cart, causing acceleration to occur in two directions. (Down corner ramps do not have this problem, as when they pass the halfway point, all perpendicular motion is added to forward motion, and after that curve, all downward acceleration is in the forward direction.)

There are two fixes to this problem. One is to simply not put corners on up ramps. The other is to take advantage of the Checkpoint Effect, below, by making a ramp (possibly including an impulse ramp) one tile in front of the ramp to make it skip through most of the tile before sideways momentum can be built.

=== Checkpoint Effect ===
The checkpoint effect, [http://www.bay12forums.com/smf/index.php?topic=144328.0 explained in depth by Larix], is an odd and highly exploitable feature of ramps where minecarts "teleport" through the next tile of track, ignoring nearly all minecart physics (except that they stop at all walls or other obstacles and not only respect curves, but will take them even when they would otherwise derail) and passing through that tile in just a single tick, and into the next tile at the halfway point.

This effect occurs when a cart leaves a downward ramp for any other direction of tile. (This includes ramps which accelerate in different directions, even a ramp which goes from accelerating East to accelerating North due to a bend in a chain of standard down ramps in a curve.) This allows, for example, two valid straight ramps directly next to one another with a cart dropped onto one or the other with no momentum to have the cart pick up acceleration going "down" the ramp as normal, but then flying up through the "up" ramp it travels into with no loss of momentum, as though it had come from an impulse ramp. If the two ramps had at least one space of distance between them, and then a cart were dropped in, the cart would instead "rock" back and forth between the two ramps.

This seems to be because ramps have a slightly longer length than regular tiles - 144,000, rather than 100,000 distance. When this "snaps back" after a ramp, it seems to project the cart suddenly further along the track, making it jump a tile ahead even when otherwise moving at relatively low speeds.

This [[bug]] is the cause of a ''wide array'' of unexpected behavior among people who do not take this bug into account. It causes derailments or failure to climb up seemingly valid impulse elevators. In general, it makes a system that behaves extremely counter-intuitively, and operates ''any time a cart encounters a valid ramp''. At the same time, when its effect is accounted for, it is highly exploitable: It causes "perpetual motion devices" using no power when two opposing ramps are placed next to one another, since the "uphill" effect of the opposing ramp is ignored, preventing deceleration.

Another useful thing to note about this exploit is that carts traveling at no less than 72,000 or so speed (enough to travel half a ramp tile in a single tick) can travel through every tile in just one tick at no change in velocity as long as the tiles alternate between impulse ramp or actual down ramp and any other tile type. The cart checkpoints through the non-down-ramp tiles, and can pass through the (impulse) down ramp tiles in a single tick, before they can actually start gaining momentum.

=== Falling ===
When falling, a minecart appears to cause no damage upon collision, possibly to allow cart "stacking" across Z-levels.{{cite devlog|2012|04|06}} A dwarf riding in a minecart that is dropped multiple z-levels suffers normal fall damage. Minecarts can fall through up/down stairs.
The cart falling (from a hatch, thus with no horizontal speed) onto a track ramp is accelerated as if starting from the middle of the ramp - i.e. to the same speed, no matter how many Z-levels it was dropped, vertical velocity is negated. {{cite forum|144328/5701211}}

=== Stacking ===
If a minecart lands on top of another minecart, they may form a stack, with the upper cart on the z-level above the lower. Subsequent carts do not form a stack, but rather quantum stockpile in the same space. This behaviour is useful for [[megaprojects]] and [[trap design]] with minecarts as the weaponry. Moderation should still be exercised: carts take longer to fall into a "stacking" tile already occupied by other carts and will spend that time "hanging" in the air above the stack. This can lead to following carts striking them, which can cause all kinds of malfunctions. The extra time is two game steps for every cart already in the stack, which doesn't hurt stacks of ten carts very much but makes stacks of 100+ rather impractical.

These minecarts on the upper level generally need to be struck with another minecart to move out, or have their support removed. The latter option is safest done by shooting it away with another minecart, manual removal of a stack-supporting cart typically causes the next cart from the stack to [[fun|fall on top]] of the hauler.

=== Perfectly Elastic Collisions ===
Minecart collisions are perfectly elastic, meaning that not only do minecarts not take damage, but that two carts that are rolling which have frontal collisions of near-similar speed, and where one cart is no more than twice the mass of the other cart, will result in a billiard-ball-like effect of the lighter cart bouncing off the heavier cart with a proportional speed increase dependent upon the relative momentum behind the heavier cart.

Using this trick with carts already at the 270,000 maximum speed from ramps can result in "supersonic" carts traveling at speeds in the millions (travelling a dozen tiles per tick), but where they are suddenly subject to 10,000 units of "terminal velocity" friction per tick. [http://www.bay12forums.com/smf/index.php?topic=137557.0 Thread with SCIENCE here].

While hypothetically capable of launching a minecart into orbit when used in conjunction with a ramp, no cargo can be contained in the launched cart, as the collisions will force ejections of the cargo. Your "unwilling volunteer" [[goblin]] space pioneers will simply become paste underneath the wheels of an extreme high-speed cart.

=== Numbers behind the scene ===

According to early research by '''expwnent'''{{cite forum|112831/3536975}}:

The minecart has a variable for speed. Speed is measured in tiles/100000 ticks, so a speed of one hundred thousand means one tile per tick. By going down a large number of ramps, a maximum speed of 270,000 can be reached, which presents the limit for most practical applications. Short bursts of (much) higher speeds are possible through carefully planned collisions of high-speed carts {{cite forum|137557/5145499}}.

Every tick the cart accumulates distance units, as well as slows down depending on current tile (speed is reduced by "friction" of the tile). The cart will move to the next tile the tick before accumulating 100000 distance units, (or several tiles in case of great speed), then the leftover distance units are added to the default 100000 distance u. of the next tile. Since most deceleration and acceleration is applied per step, with the notable exception of corners, a cart going at twice the speed of another one can cover about four times the distance in a straight line, but only twice the distance along a winding track with very many corners.

A push will teleport a cart to the beginning of the next tile (NOT the middle!) in one tick with 19990 speed (10 speed is lost due to track friction), while a roller will give a cart the roller's set speed, and it will start to accumulate regular track friction past the middle of the roller tile. Some track features will affect a minecart when it is past the middle of the previous tile: entering a ramp or a hole/drop will happen when the cart has left the middle of the previous tile, and the ramp will gain additional distance unit depending on the leftover units from the previous tile. When a cart leaves a ramp it will emerge after one tick in the middle of the next regular tile, so its entry coordinate is "50000-speed+friction". Rollers also affect the speed of minecart from the middle of the previous tile.

Friction of tiles:
{| class="wikitable"
|-
! Tile
! Friction
! Comment
|-
| Tracks
| 10
|-
| Ground/Floor
| 200
|-
| Unusable ramp
| 10
|-
| Upwards ramp
| 4910 (10+4900)
|-
| Downwards ramp
| -4890 (10-4900)
|-
| Roller
| ±100000 (but capped by the set speed)
|-
| Corner track
| 10
| Speed reduced by 1000 upon leaving the corner tile
|-
| Track stop (highest)
| 50000
|-
| Track stop (high)
| 10000
|-
| Track stop (medium)
| 500
|-
| Track stop (low)
| 50
|-
| Track stop (lowest)
| 10
|-
| Water 1-6
| Additional (WaterLevel - 1) * 100
| rowspan="2" | [[#Skipping|See Skipping]]
|-
| Magma 1-6
| Additional (WaterLevel - 1) * 500
|-
| Empty space
| 0
|}

Water of depth 7/7 provides a friction of about 10000 per step, as does maximum-depth magma. This higher friction may not apply to very slow-moving carts.

Impulse sources:
{| class="wikitable"
|-
! Feature
! Speed
|-
| Push
| 20000
|-
| Roller lowest
| 10000
|-
| Roller low
| 20000
|-
| Roller medium
| 30000
|-
| Roller high
| 40000
|-
| Roller Highest
| 50000
|-
|}

== Non-standard uses ==
Minecarts include some interesting characteristics that have motivated uses beyond hauling. They can be useful for creating fully-automated [[exploit|quantum stockpiles]] and [[garbage disposal]]s. Storing perishable goods (meat, meals, etc.) inside a minecart appears to guard against rot and vermin.
Minecarts can be [[Trap_design#Minecarts|used as weapons]], or as (hopefully non-fatal) triggers to restart stalled [[healthcare]]. They can also be used to time/control game events, either using a basic [[repeater]] or much more advanced [[minecart logic]].
Minecarts trigger [[pressure plate]]s, which means a trap can be designed to trigger when a thief attempts to steal a minecart.
A pressure plate can be used as automatic and more precise custom "launch when full enough" system - as long as weight of your minecarts stays the same. You cannot build a hatch or roller on the same tile, so launch by bumping with another cart. {{cite forum|15096/4580050}}
Dwarves riding minecarts can attack enemies within reach (which goes back to dev log). This applies to shooting, and they actually can hit targets while riding by.{{cite forum|109460/5266119}} Whether a minecart protects the rider and how it interacts with dodging is not known yet. Minecart riders can also [[Swimming#Minecart_training|train swimming]] and [[Megaprojects#Surveillance_Track|detect ambushers]].

== Adventure mode ==
In addition to being used for hauling, minecarts can also be ridden in [[adventure mode]]. (Adapted from forum thread {{cite forum|122903/4258212}})

# If the minecart is in your inventory, drop it. If it is already on the ground, proceed to step 2.
# Press {{k|u}} when you are 1 tile away from the minecart (or standing on the same tile as the minecart).
# You will be presented with the following options:
[[File:minecart adventure mode menu.png|left]]
{{clear}}
* If you {{DFtext|Push}} the minecart, it will move a few tiles in the direction you chose. Physics comes into play here, so it will gain/lose speed depending on the usual factors.
* If you {{DFtext|Ride}} the minecart, you will hop into the minecart, even if you were a tile away, and it will move in the chosen direction with you in it. It will gain/lose speed depending on the usual factors. Whilst the minecart is in motion, you should press {{k|.}} to skip your turn; if you attempt to move whilst the minecart is still in motion, the laws of physics come into play, and you will take [[wound|damage]]. Alternatively, you can push the minecart whilst it's still in motion (although it's unclear how one can bend [[physics]] so as to push a moving minecart whilst inside the minecart). If you push it in the same direction you are already travelling in, you will greatly increase the minecart's velocity. You can also push it in different directions, and this will cause it to gradually change direction-the amount of pushes this requires depends on the minecart's velocity. Once the minecart has stopped moving, you may move out of it safely, or you may want to give it another push. Note that if you push a minecart right after having ridden it (still on the same tile as the minecart), it will act as though you chose to ''ride'' it.

If you want to test this out without creating an adventurer, the [[object testing arena]] allows you to spawn minecarts ({{k|k}}-{{k|c}}-{{k|n}})

== Forging and Melting ==
* Metal minecarts cost '''two''' [[metal]] bars to forge, or '''six''' [[adamantine]] wafers.
* When a non-adamantine metal minecart is melted down, it will return '''1.8''' metal bars, for an '''efficiency of 90%'''.
* When an adamantine minecart is melted down, it will produce '''1.8''' wafers, for an '''efficiency of 30%'''.

== See also ==
* [http://www.bay12forums.com/smf/index.php?topic=109460.0 The "How Does Minecart" Thread] by '''Girlinhat''' et al.
* [http://www.bay12forums.com/smf/index.php?topic=112831.0 SCIENCE: Quantifying minecart physics] by '''Snaake''' et al.
* [http://www.bay12forums.com/smf/index.php?topic=129676.0 How to build a Multi-cart Ore to Magma Minecart Project without needing power] by '''WanderingKid'''.
* [http://www.bay12forums.com/smf/index.php?topic=144328.0 My very own Minecart Education Thread. Ten Lessons, now complete.] by '''Larix'''.

== Bugs ==
*A dwarf will drop her [[child|baby]], if she has one, when boarding a minecart set to be ridden.
*Dwarves have no concept of traffic safety and will walk into busy minecart lines to retrieve objects, often with deadly consequences. This is especially problematic in [[Swimming#Minecart_training|clever applications]] depending on dwarves riding the carts very frequently, because they have a bad habit of dumping their worn clothes on the tracks after a minecart ride. Adding an automatically-operated [[hatch cover]] at the end of such a ride can help prevent [[unfortunate accident]]s.
*Dwarves cannot guide a minecart through an unlocked door unless another dwarf opens the door.{{bug|6056}}
*It is possible for a creature and minecart moving towards each other to pass without collision if they exchange tiles in the same tick.
*After a minecart ride, a dwarf will sometimes haul the minecart to a storage stockpile, leaving another dwarf to haul the vehicle back to the route.
*Minecarts falling onto a floor injure creatures in the tile below the floor.{{bug|6068}}
*A minecart's initial velocity is not affected by weight, when pushed or launched from rollers.{{bug|6296}}
*Removing a stop that has a vehicle waiting on it may cause the game to crash.{{bug|5980}}

{{Category|Fortress mode}}
{{Category|Interface}}

[[ru:Minecart]]

Minecart

2015-06-18T02:12:34Z

NW Kohaku: /* Physics */

{{Quality|Masterwork|08:15, 19 May 2015 (UTC)}}
{{av}}
A '''minecart''' is a [[tool]] intended for [[hauling]], introduced in version 0.34.08. It can be made of [[wood]] at a [[carpenter's workshop]] or [[metal]] at a [[metalsmith's forge]] (using the [[Metal crafter|metalcrafting]] labor.) Minecarts store up to five times as many items as [[wheelbarrow]]s and are quite a bit faster than dwarves hauling objects by hand, but have the disadvantages of requiring a dedicated track network, a complex route planning phase, and the possibility of dwarves [[Fun|blundering into the path of carts filled with lead ore]]. Tracks may be carved into stone, or [[Construction|constructed]]; the latter allows above-ground routes, but these are more difficult to set up due to their additional [[building material|material requirements]].

Just like wheelbarrows, minecarts are considered [[item]]s and are stored in a [[furniture]] [[stockpile]]. Despite their five-times-greater capacity, they are only 33% larger than wheelbarrows and are identical in base [[item value|value]] when made from the same [[material]] (the value may differ due to the [[item quality]]). [[thief|Thieves]] or even mischievous animals can steal minecarts, even when they are moving on a track{{cite forum|109460/3289070}}. However, minecarts moving fast enough or being ridden cannot be stolen.

Although most of the utility of minecarts is in [[fortress mode]], an [[adventure mode|adventurer]] can also ride in a minecart. Adventurers can also pick up and relocate minecarts.

The invention of minecarts revolutionized the [[minecart logic|Science of Dwarfputing]] by enabling smaller, faster logic systems to be built.

== Basic Minecart Usage ==
Minecarts can be used to swiftly transport dwarves, [[flow|fluids]], and/or large amounts of items, but before you have a functional minecart there are several preconditions that need to be met. First of all you need an actual minecart, constructed either in a [[carpenter's workshop]] or [[metalsmith's forge]]. For the minecart to be able to move you also need to carve (with {{k|d}} {{k|T}}) or construct (with {{k|b}} {{k|C}} {{k|T}}) a track, which could be as simple as a straight line. Finally you need to construct stops on your track (with {{k|b}} {{k|C}} {{k|S}}) where the minecart will start and stop.

After you have created the stops and assigned a cart to the track, you must create logic routes connecting several stops and designate starting conditions for each stop. This is done with the {{k|h}}auling key. The most basic conditions are how the cart's movement is initiated and in which direction the cart should start moving. Carts can be either be Pushed (a dwarf stands at a stop and gives the cart a single push) or Guided (a dwarf continually pushes the cart forward, guiding it along the track). The [[hauling]] [[labor]] required for pushing and guiding carts is called "Push/Haul Vehicles" and is turned on by default.

To control which items to transport you can add conditions specifying: (1) which kind of items to be loaded, and unloaded, (2) stockpile links to define which stockpile(s) the items should be un/loaded to and from.

===Capacity and weights ===
Minecarts have five times the [[Weight|capacity]] of [[wheelbarrow]]s.

'''Examples of the capacity of one cart'''
{| class="wikitable"
|-
! Item
! Amount
|-
| [[stone]]
| 5
|-
| [[wood|log]]
| 10
|-
| [[block]]/[[bar]]
| 83
|-
| [[Kitchen|prepared meals]]
| 500
|-
| [[Trap_component#Spiked_ball|spiked balls]]
| 500
|-
| [[Weapon#Native_weapons|mace]]
| 625
|-
| [[Weapon#Native_weapons|spears]]
| 1250
|-
| [[cloth]]
| 2500
|}

The weight of the loaded minecart does not affect the initial velocity received from pushing or launching from a roller. However, the load of a minecart ''does'' affect whether a [[pressure plate]] triggers or not, based on the pressure plate's setting.

'''Weights of different carts'''

{| class="wikitable"
|-
! Type of cart
! Empty cart
! Fully loaded (items)
|-
| oaken minecart
| 28Γ
| 378Γ (10 oak logs)
|-
| platinum minecart
| 856Γ
| 10482Γ (83 gold bars)
|}

The weight of a minecart is one twenty-fifth (1/25) the [[density]] of its material in Urists. Because pressure plates can be set to trigger at intervals of 50 Urists, minecarts with weights just under a multiple of 50 are ideal for switching based on whether they're full or empty. The best minecart materials for full/empty switching are as follows:

{| class="wikitable sortable"
|-
! Material !! Minecart weight !! Content weight required to trigger !! Banana roasts required to trigger (for scale)
|-
| [[Bismuth]] (moods only) || 391 || 9 || 15
|-
| [[Brass]] || 342 || 8 || 14
|-
| [[Electrum]] || 596 || 4 || 7
|-
| [[Fine pewter]] || 291 || 9 || 15
|-
| [[Glumprong]] || 48 || 2 || 4
|-
| [[Lay pewter]] || 291 || 9 || 15
|-
| [[Nickel silver]] || 346 || 4 || 7
|-
| [[Tin]] || 291 || 9 || 15
|-
| [[Trifle pewter]] || 291 || 9 || 15
|}

=== Creating tracks ===
Minecart tracks are made up of contiguous track, tracked ramp, or bridge tiles. Track tiles and tracked ramp tiles have a direction or series of directions associated with them. These directions dictate which directions a minecart on a given tile may move from that tile. For example, a Track NE (northeast) tile allows a minecart on it to move either north or east from its present position. Therefore, if you want your minecart to move east along a straight piece of track, then return west using that same track, you would need to use EW tracks so that the cart could travel east initially, then return west over the same track. Excluding designs in which the cart will "jump" tracks via a drop or other ramp, tracks must be valid end to end to work for most looped or straight-track applications. A single east only track tile in your line of east-west tracks will cause any route using the track to fail the moment it tries to go the wrong way over that tile. Minecart tracks can be built in two ways: Engraved/carved or constructed. A given minecart track need not use engraved or constructed elements exclusively, as the two methods can be used interchangeably depending on the needs of a given section of track. The way the tracks are built is slightly different between the two, as explained below.

====Simple tracks====

'''Carved'''

A single-tile wide strip of natural stone can be designated to be [[Engraver|carved]] (with {{K|d}} {{k|T}}), which will create a straight two-way track. The creation of corners, crossings, and T-junctions is as simple as designating another strip of track that overlaps an existent or newly designated track. Engraved tracks are removed by [[smoothing]] the rock they're on, which results in a smooth floor (that can be re-engraved if necessary), or by building a [[floor]] on top and subsequently removing it. Dwarves can carve corner tracks in one pass by designating the track carving twice and canceling unwanted carvings (with {{K|d}} {{K|x}}). Tracks can be engraved in any natural floor tile, rough, smooth and even over engravings, providing an easy method to remove low-quality or undesired floor engravings. Once a track has been engraved, it's important to check the track directions for each tile in the route carefully to make sure no mistakes were made by yourself or the game's track engraving logic.

'''Constructed'''

Tracks can also be built as regular [[construction]]s (through {{K|b}} {{K|C}} {{K|T}}). This method is resource-expensive, since each track tile requires one stone, [[bar]], or [[block]] for construction, and time-consuming, since you can't designate strips longer than 10 tiles at a time. Corners, crossings, T-junctions, and ramps also have to be designated individually. However, it is usually the only way to build tracks above ground or on soil (barring the [[Obsidian farming|creation of obsidian]]). Constructed tracks are designated for removal like any regular construction; be aware that removing track ramps built on top of natural ones will also remove the original ramp, leaving a flat floor.

====Ramps====

'''Carved'''

The carving of natural ramps is a little more confusing: to carve a two-way track on a ramp (natural only, does not work on constructed ramps), you must designate the track '''starting on the ramp and one square beyond''' in the direction you want the track to go. For the side of the ramp square you want to head upward, there '''must''' be either a natural or constructed wall in the square next to it, otherwise the game assumes you are trying to carve it on the same level -- this can result in the track being carved underneath a door or other object. If you have accidentally done this, you can correct it by smoothing the ramp and constructing a single square of wall next to it, then re-carving the ramp correctly. (However, the wall must stay there permanently; removing it will disconnect the track.)

'''Constructed'''

When constructing track ramps, the stated direction should be the same as the connected tracks. For example, a track going up from West to East would require, starting from the West, a Track (EW), a Track/Ramp (EW) and a Wall behind the ramp, underneath the section of track above it. Incorrectly placed ramps result in minecarts ignoring the ramp and crashing into the supporting wall. They will not, however, display as unusable as when the supporting wall is missing.

'''Examples of ramps'''

A simple ramp would look like this:
{{diagram|spaces=yes|\
z +0 z +1
░░░░ ░░░░
═▲o ░▼═
░░░░ ░░░░
o : wall
}}

Carving track corners into ramps is rather unintuitive and complicated. Since engraving tracks always requires two tiles to connect in a straight line as input, you have to give two separate designations for a single job: a track bit from the ramp tile to the "below" direction and another one to the wall of the "upward" direction. If you wanted to change direction on a ramp from east to north:
{{diagram|spaces=yes|\
z +0 z +1
░░░░░ ░░░░░
░░░░░ ══╗░░
=▲░░ ░░▼░░
░░░░░ ░░░░░
}}
you would need to connect the ramp on z +0 both to the west and to the north by issuing two "carve track" commands, one selecting the ramp and the track tile to the west, and another connecting the ramp tile with the wall to the north. An engraver would then carve a NW track corner into the ramp, allowing carts to pass the corner correctly both going up and down. Such track corners are perfectly serviceable for guided carts, but moving down a route of several of them by pushed or ridden cart is problematic - ramps on corners behave very counter-intuitively, resulting in loss of speed when going down and diagonal movement when going up.

Moving to and from ramps (or between ramps "pointing" in different directions0 causes some non-trivial adjustments to speed and even moving along the tiles at a fixed speed ''unrelated to the entry/exit velocity values'', because transitions to/from ramps are processed differently and are not to be "skipped". This affects compact track/ramp combinations (such as e.g. a simple 2x2 ramp spiral) most, and combined with bouncing often makes them work not in the way one could expect. {{cite forum|144328/5705102}}

{{anchor|Tracks}}

=== Hauling route ===
A hauling route is a list of directions describing how and under what conditions a minecart will move. The proper setting up of routes is essential for a working rail system. Routes, stops, departure conditions and stockpile links are managed from the {{k|h}}auling menu.

==== Route ====
A route defines the path a minecart will take along a track, as well as under what conditions it will move or stop moving. A route is made up of stops. Stops are precisely what they sound like, a position on the track at which you want a minecart to stop. A minecart track might use as little as a single stop for a looped track, which will serve as both a starting and stopping point for the cart, or it could contain many stops, perhaps to load supplies or wait for a bridge to be manually lowered, before reaching its destination or returning to its starting point. It is important to note that you only need to place stops on a route where you actually want the cart to stop and wait for some action to occur. They are not needed to help navigate the cart along the track beyond telling it where on the track to stop.

New routes are created with the {{k|h}}auling key. Existing ones can be removed (without confirmation) with the {{k|x}} key, and also {{k|n}}icknamed. Before operating, the route must have a {{k|v}}ehicle assigned to it (this can be done with either the route or a stop selected). Assigning a full minecart to a route may result in a slow hauling job if the contents are heavy.

==== Stops ====
Stops are the individual waypoints that make up a hauling route. A given stop consists of the location of a tile, as well as conditions describing when, where, and how a cart should be moved after being stopped at that tile. Stops can be created from within the {{k|h}}auling menu, by placing the cursor over a tile and hitting {{k|s}} while highlighting the route (or a stop within) you've already designated. A minecart will begin its route at the first stop created, and continue through each subsequent stop, being guided, pushed, or ridden from each stop to the next depending on the conditions specified. In many basic minecart applications, the cart will end up at the same stop it began at, though this is not always the case. It is important to note that hauling stop order is enforced, even if there is no track. A dwarf will drag the cart overland back to a skipped stop in the route's list if your tracks bypass it somehow.

Once a stop has been placed, it is given a default set of conditions under which to move the minecart if it is stopped there. Each new stop gets the same default conditions regardless of the track it is placed upon (e.g. guide the cart to the north). For this reason new stops might get marked by yellow exclamation marks ({{DFtext|!|#ff0}}) due to invalid directions. One important thing to note is that as you place additional stops, the display will show paths between the stops you have defined. However, this is '''not''' necessarily the actual route the minecart will take once the route is in operation. For example, if a route were defined with two stops at opposite ends of a track with many twists and turns, a line will be drawn directly between those stops to show the order in which they will be visited. These route lines may crisscross all over the tracks, but so long as the track is valid end to end, the cart will follow the track from one stop to the next, even across twists, turns, and z-level changes. Stops, which are the steps that make up a route, should not be confused with Track Stops, described below.

===== Stockpile links =====
By placing the cursor on top of a stockpile and using {{k|s}}, you can create stockpile links while defining a hauling stop. Links can also be redefined by selecting them, placing the cursor over a different stockpile, and pressing {{k|p}}. The cart will then be filled by items present in its various linked stockpiles in preference to other items. Note that bins should be used with caution in stockpiles that are linked to minecarts. Bins cause problems when used with the "Desired Items" list in a stop's conditions. For example, if a minecart is set to accept only granite blocks, and to depart north when it is 100% full of granite blocks, it will not depart if any of those granite blocks are in bins, even if bins are also included in the desired items list. Two solutions to this problem exist as of v0.40.24. First, bins can be disallowed in stockpiles that are linked to stops. Alternatively, bins '''can''' be used in conjunction with minecarts provided that the minecart's departure conditions use only "any items" instead of "desired items." This option can be toggled in the advanced conditions menu for a stop, accessible via the {{key|C|}} key. The cart's contents can still be controlled by specifying what items are allowed in the linked stockpile.

===== Departure condition =====
Departure conditions involve setting conditions in which the minecart will leave on the route. Each condition includes:
# A departure mode (Guide, Ride or Push).
# An initial departure direction (NSEW). Note that this defines the initial direction of movement only. Even if a track includes many turns, as long as the initial movement direction is valid the cart will follow the minecart track thereafter.
# A timer, before which the departure condition cannot be met.
# Conditions on the amount of items in the cart.
Departure conditions are created with the {{k|n}} key. A new departure condition will read: "guide north immediately when empty of desired items". This condition can be changed between basic presets with {{k|c}}. "Advanced" mode ({{k|C}}) allows for more precise control over departure conditions: fine tuning the percentage from 0 to 100 in 25% steps ({{k|f}} and {{k|F}}), switching it being either the maximum or the minimum amount of items for the condition to be met ({{k|m}}), and whether the cart accepts all or only a specific set of items ({{k|l}}). Common to both screens are the departure mode ({{k|p}}, Push, Ride or Guide), {{k|d}}irection, and timer ({{k|t}} and {{k|T}}) options.

To have a cart only carry a specific set of items, the stop can be set to only carry "desired" items, opening the selection screen with the {{k|Enter}} key while having said stop condition selected, and toggling as desired, or it can simply be linked to a stockpile and set to depart once it is full of items from its linked stockpiles, regardless of type.

=== Track Stops ===
A Track Stop, not to be confused with a route stop, is an optional, single-tile construction which serves two purposes. First, it can be used to cancel a cart's momentum in order to slow or stop it as it passes over the Track Stop. This might be necessary if a cart were pushed down a series of ramps to its destination. Second, a Track Stop can cause a cart to automatically dump its contents as it passes over the Track Stop. Track Stops are constructed via {{k|b}} {{k|C}} {{k|S}}, and must be constructed atop an existing piece of track. If a Track Stop has been set to automatically dump a cart's contents, the cart will dump its contents in the direction indicated when it passes over the Track Stop. Depending on the friction settings chosen for the Track Stop, the cart might then stop after dumping, or it might continue on its route to another destination.

Track Stops are not mandatory; in fact, their main use is in automated rail systems. However, even in basic rail systems it can be useful to set a Track Stop to dump items: this saves time that dwarves would otherwise spend in removing items from the cart, time that is better spent driving the cart back to where it's needed. Dumping will occur even with a guided cart. '''Take care not to set Track Stops at a loading site to dump their contents''', or dwarves will never be able to fill the cart. It will dump any contents the moment they are loaded.

Counter-intuitive to their construction method, Track Stops are considered [[building]]s and must be removed by {{k|q}} {{k|x}}.
* See [[#More_on_Track_stop |More on Track Stops]]

=== Step-by-step tutorial ===

Let's construct a simple minecart route. This route will move stone blocks from an input stockpile to an output stockpile. We'll begin by creating the stockpiles:

[[File:minecart-example-1.png|Stockpiles designated.]]

The input stockpile is on the left; the output stockpile is on the right. We'll be moving blocks from left to right. Disable bins in both stockpiles, and set the input stockpile to accept only from links. Then make the stockpile take from the mason's workshop where the blocks are being produced.

Next, carve the track:

[[File:minecart-example-2.png|Track carving designation.]]

Note that the ends of the designation are uniquely shaped; this is automatic, and not anything you need to control. Now, wait for your engravers to come along and carve the track into the stone. (Your haulers will probably also fill up the input stockpile while you wait.)

In addition, while we're waiting for that to happen, we'll build an iron minecart in the forge.

[[File:minecart-example-3.png|Track carved.]]

When the track has been carved, it will look like the above (the track will be solid instead of flashing). Now, order a track stop to be constructed next to the output stockpile:

{|
| [[File:minecart-example-4.png|Track stop designation.]]
| [[File:minecart-example-5.png|Select dumping direction.]]
|}

You must press {{k|d}} three times to select the dumping direction ''before'' placing the track stop. We want our blocks to be dumped into the output stockpile east of the track stop. Then wait for a mechanic to come along and build the track stop.

[[File:minecart-example-6.png|Track stop constructed.]]

Now we'll define the actual ''route''. This is done in the {{k|h}}auling menu. Press {{k|r}} to begin defining a route. Next, move the cursor to the input end of the track, and then press {{k|s}} to define the first stop:

{|
| [[File:minecart-example-7.png|Stop 1 designation.]]
| [[File:minecart-example-8.png|Route definition, in progress.]]
|}

Move the cursor again, to the output end of the track, and press {{k|s}} again to define the second stop:

{|
| [[File:minecart-example-9.png|Stop 2 designation.]]
| [[File:minecart-example-10.png|Route definition, two stops.]]
|-
|
| [[File:minecart-example-11.png|Stops are not defined yet.]]
|}

There are several user interface features to note at this point. The stops have been positioned, but they haven't been ''defined'' yet, so there is a warning {{DFtext|!|#ff0}} symbol by each of them. In the lower right corner, we see what the {{DFtext|!|#ff0}} means. Also, note that the second stop is labeled in white, while the other two lines are grey. The white text is a selection indicator, and can be moved up and down by pressing {{k|+}}/{{k|-}}.

Next we need to define what our stops do. We want the minecart to be filled with blocks at the first stop, then travel to the second stop where it will dump its cargo, and then return. Press {{k|-}} to move the selection up to stop 1, and {{k|Enter}} to open it up. By default, the stop has three conditions:

[[File:minecart-example-12.png|Default stop definition.]]

We don't want any of these, so press {{k|x}} three times to delete them. This leaves us with a blank stop. Now we can add the conditions we actually want. Press {{k|n}} to begin adding the first condition, then {{k|d}} twice to change the direction from north to east. Then press {{k|c}} to change the condition from empty to full. This will instruct the minecart to be guided east when full of desired items.

To set the desired items, we create a stockpile link. Press {{k|s}}, then move the cursor to the input stockpile, then press {{k|p}} to select that stockpile. Now press {{k|Enter}}; this opens up a selection screen that resembles the stockpile customization screen. Move down to Blocks, {{k|e}}nable them, then (if you wish) restrict it to stone blocks.

When you've done all that, stop 1 should look like this:

[[File:minecart-example-13.png|Stop 1, defined.]]

Stop 2 is much simpler. All we need to do is have the minecart return to the input stop. So, make a condition and change the direction:

[[File:minecart-example-14.png|Stop 2, defined.]]

Finally, we just have to assign our minecart. Go back to the route definition screen, and press {{k|v}}. Select the minecart, and press {{k|Enter}}.

Now we've got everything set up:

[[File:minecart-example-15.png|Route, fully defined.]]

The V is red because the minecart hasn't been moved onto the track yet. Some dwarf will have to haul it from the forge to the first stop, by hand; this will take a while, especially if the forge is far away.

Once the minecart is in place, dwarves should fill it with blocks from the input stockpile, which will in turn be filled with blocks from the workshop where your mason has been toiling dutifully. When the minecart is full, the blocks will be dumped into the 1x1 stockpile on the right. Automatic quantum dumping!

=== Troubleshooting ===

Because of the complexity of the system, all but the most careful and experienced minecart users will encounter issues. Most route issues can be diagnosed and fixed from the {{k|h}}auling menu.

'''Symptom:''' {{DFtext|! Set dir/connect track|6:1}} message appears to the right of one or more stops

'''Possible Causes:'''
* The departure direction of the stop might be invalid. Edit the stop using {{k|Enter}} and press{{k|d}} until it is pointing in a valid direction.
* The track stop might not be built on top of a track. The track stop must be deconstructed to remedy this issue.
* Your track might not be built correctly. Make sure all connected tracks between destinations are not one-way tracks.
** This can be especially confusing with ramps. To carve a two-way track on a (natural) ramp, you must designate the ramp and one square beyond in the direction you want the track to go.
** Ramps '''must''' have a solid block on the side opposite to the track, or they will neither work nor be marked as "unusable". The solid block can be natural or constructed.
* The desired/kept items might not be configured correctly.

'''Symptom:''' The status '''0% V''' always appears to the right of one stop.

'''Possible Causes:'''
* The stop may not be set to take from a stockpile. Edit the Stop using {{k|Enter}} and make sure you see a message like "Take from Stockpile #1".
* The take conditions must correspond with the contents of the stockpile.
* The track stop may be set to dump. A track stop set to dump cannot be filled. You must either set the stop to a time-based departure or deconstruct the track stop and rebuild it without dumping. (Alternatively, with [[DFHack]] you can modify "Dump on arrival" to "No" using the {{key|q}} menu without rebuilding the stop.)
* Make sure the minecart itself has not been designated to be dumped (such as when using mass-dump).

'''Symptom:''' Dwarves fill the minecart properly, but will not move it thereafter.

'''Possible Causes:'''
* The minecart may contain items which are not included in its current stop's desired items. Check inside the minecart using the {{key|k}} and {{key|z}} keys and ensure that all items in the cart are desired items.
* The minecart may contain desired items in bins. Minecarts seem to have problems realizing that they are in fact full of desired items if some of those items are in bins, even if bins are also among the desired items for that stop. '''This cannot be solved by adding the appropriate bins to the stop's desired items.''' Either disallow bins in stockpiles you intend to load minecarts from, or set the departure conditions to rely only on percentage of total load rather than percentage of desired items using the advanced conditions menu ({{key|C}} key).

'''Symptom:''' Dwarves repeatedly attempt to load the minecart, but no items are ever loaded into it.

'''Possible Causes:'''
* This can be caused by using a Track Stop with autodumping enabled at a loading site. Every time a dwarf places an item into a cart resting on such a track stop, the item will be immediately dumped, causing unlimited, useless cart loading jobs. Autodumping Track Stops should never be used at a loading site.

'''Symptom:''' A dwarf picks up the minecart and carries it to its destination.
* See [[#Quirks|Quirks]]

=== Danger ===
Minecarts are not without <strike>danger</strike> [[fun]]. Although designating a track automatically sets the [[traffic]] designation to low, dwarves ''may'' still walk on them, and [[creature]]s ignore traffic designations altogether. If an unlucky dwarf or creature fails to [[dodger|dodge]] a minecart, they can be injured. Most of this danger can be avoided by setting the minecart {{k|h}}auling commands to guide instead of push or ride (dwarves guiding minecarts will ignore traffic restrictions), as well as by [[pasture|pasturing]] domestic animals and preventing the access of other creatures to the tracks. Note that removing the track doesn't reset that tile back to normal traffic priority, so you may wish to manually clean up traffic designation afterward. Also note that bridges that are used as tracks don't have their traffic priority changed automatically (since they're just normal bridges), which could cause dwarves to pathfind normally through dangerous minecart entrances in your fort's walls if you're not careful.

The only <s>fool</s>''dwarf''-proof method is to make the tracks inaccessible. There are several ways to create a track which works for minecarts but doesn't allow creature-traversal; the simplest is perhaps building a [[statue]] on the tracks. Other options include adding single-tile holes (minecarts moving at reasonable speed will jump the gap), vertical drops, minecart-triggered doors, small pools of liquid (4/7 water or 2/7 magma), and hostile creatures overlooking the tracks. For safety, both ends of the track should be isolated, making the dangerous center sections completely inaccessible (though maintenance access can be provided by a locked door).

Danger does not always involve living victims: careless route designation can also result in minecarts careening off tracks or colliding with each other. If this occurs, the [[item]]s may be scattered; this can cause even more hauling jobs than the minecart aimed to eliminate. Even <s>better</s> worse, scattered items, especially [[weapon]]s, can injure passing [[dwarf|dwarves]] or other [[creature]]s; in the words of Toady One the Great, "Accidental grapeshotting of the dining room should be possible now."

Of course, the danger of using minecarts means they can also be [[Trap_design#Minecarts|used as weapons]] by imaginative players.

== Advanced usage and automation ==
Minecart-specific effects are implemented via track stops, rollers and [[pressure plate]]s with "track" condition set. Since all three are considered [[building]]s, they can't be built on the same square (however convenient track stop + pressure plate would be) nor a simple ramp, and are removed by {{k|q}} {{k|x}}.

=== More on Track stop ===
Track stops are constructions that allow further automation of minecart systems via adjustable features such as braking by friction and automatic dumping of contents. They can be built from logs, bars and blocks through {{K|b}} {{K|C}} {{K|S}}; friction amount, dumping toggle and dumping direction must be set '''before''' construction, and these settings can be neither changed nor seen thereafter; however, track stops can be linked to [[pressure plate]]s or [[lever]]s to toggle friction and dumping On or Off (trigger state is inverted: switch On = track stop Off).

If a [[stockpile]] is placed on the tile that a track stop is set to dump to, it can act as a [[Exploit#Quantum_stockpiles|quantum stockpile]] and any items dumped from a minecart that match the storage settings of the stockpile will remain there and accumulate. Normally trackstops are built on top of existing track to operate on moving minecarts, but they can also be used without tracks to create [[Exploit#The_Minecart_Stop|automatic quantum stockpiles]] (see also [[#Step-by-step_tutorial|step-by-step tutorial]]). It is not always desirable to collect ALL of certain items into one quantum stockpile, such as when distributing a material to multiple separate industries. You can link your quantum stockpile to various other stockpiles, ensuring that your dwarves will keep them supplied as necessary. Because quantum stockpiles never fill up like regular stockpiles, it may be a good idea to add a switch to turn them off.

Items dumped from a minecart at a track stop (or dumped by any other means) into open space fall through z-levels until they land on a solid surface. Items falling onto a designated [[stockpile]] will automatically be considered part of that stockpile, even if the stockpile is set to disallow those items (they will, however, be automatically moved to a more appropriate stockpile, if available). Items falling on top of a minecart will '''not''' fall "inside" the minecart. Use with caution; dwarves have fragile skulls.{{bug|5945}}

=== Automated propulsion ===
==== Roller ====
{{Main|Roller}}

A '''roller''' is a [[power]]ed [[machine component]] for the automated propulsion of minecarts. They are built over the top of existing tracks with {{K|b|M|r}}, requiring a [[mechanic]], ''(length/4)+1'' [[mechanism]]s and a [[rope]]. Rollers may also be placed directly on ramps to help pull carts up Z levels. Rollers are very useful to maintain a cart's momentum along long routes, to get them to climb Z-levels without dwarfpower involved, and to get them to reach speeds unattainable by guiding dwarves. These devices are variable-length (1-10), variable-direction and variable-speed ([[Minecart#Numbers_behind_the_scene|see below]]), all traits that can be set at construction time; a roller uses two units of power per tile it is long.

Single-tile rollers transfer power in all four cardinal directions, while other rollers generally only transfer power perpendicular to their activity direction. Longer rollers can also transfer power along their activity direction if built in the correct order, although this can be hard to accomplish and is easily broken. Rollers cannot be powered from above.

Rollers have great acceleration and capped speed. Carts going faster than the roller are unaffected. If a cart moves across an active roller in the direction the roller works and moves slower than the roller's specified speed, the cart will be set to the roller's speed. A cart going against a roller's movement direction will be sent back the way it came (once again at the roller's speed), unless it was moving extremely fast: speed increment of 100000 allows to reverse carts from the full "highest" (50000) speed roller to full "highest" speed back, but ramps can accelerate a cart beyond this. {{cite forum|144328/5702453}}
A cart crossing over a roller perpendicular to its current movement direction will gain the roller's amount of speed in the perpendicular direction without directly changing its forward motion. Without an adjacent wall to constrict its movement, this will typically send a cart off the rails on a diagonal path, completely unable to follow any tracks until it collides with a wall or is otherwise brought to rest. However, if the roller is placed over a track turn and pushes ''from'' the direction of that turn's track, the turn affects carts ''after'' the roller, so they will be forced into the turn rather than derailed in a diagonal direction. {{cite forum|144328/5702453}}

{{diagram|spaces=yes|\
tracks: full:
║ ║
═╗═ ═╢═
║ ║

╢ : roller pushing from W to E
}}
If the roller is powered, carts from ''all'' directions (unless too fast) exit S, because speed imparted by the roller forces carts toward E and ''then'' into the turn.
If not powered, carts from W and N exit S, carts from E and S exit W. Carts above derail speed will ignore the turn, of course.

{{diagram|spaces=yes|\
║ ║
═╗═ ═╟═
║ ║

╟ : Roller pushing from E to W
}}
Carts from the E or W: exit W.
Carts from N: derailed diagonally, exit SW.
Carts from S: derailed diagonally, exit NW.

Rollers affects carts on a track - if placed on a floor or ramp without any tracks, they are ignored. Depowered rollers are also ignored, friction is determined by the tiles underneath.

Because of their one-way nature, rollers are unsuitable for most two-way minecart tracks (unless you set gears toggling roller A->B off while toggling A<-B rollers on). However, a minecart set to be ''guided'' is not affected by rollers at all{{cite forum|109460/3286235}} — this allows a one-way track to be used in both directions. In addition, unpowered rollers do not affect minecarts.

Care must be taken in [[glacier]]s and other extremely cold [[biome]]s, since rollers (and the machinery used to power them) will not operate when constructed on natural [[ice]] floors.

==== Impulse ramps ====
Carts can be given momentum without rollers or changing z-level through a phenomenon called "impulse ramps". A track ramp which is connected both to a wall and to a floor will ''always'' accelerate a cart towards the connected floor tile, no matter where the cart enters the tile from. This means carts can be accelerated as though dropping z-levels, even if the cart doesn't actually change z-level at all. If a track ramp faces three directions such as ╩, then two of those directions need to be facing walls for the cart to be accelerated towards the remaining direction.

Example of straight impulse acceleration:

{{diagram|spaces=yes|\
▒▒▒▒▒▒▒▒▒▒ ▒▒▒▒▒▒▒▒▒▒
═▲▲▲▲▲▲▲▲▲▲═ ═╚╚╚╚╚╚╚╚╚╚═
▒ : Wall
═ : Normal track
▲/╚ : N/E Track/Ramp
}}

If a cart enters from the left, it will speed up on every track/ramp and exit to the right going very very fast - more than one tile every step. If it enters from the right then it will bounce back impulsed by the ramp if it's going slow enough.

As another oddity, carts coming from ramps will in some cases "teleport" through most of the next tile. This can be used to send carts up levels with minimal loss of speed. You can just make an upward spiral alternating impulse ramps and regular upward ramps. It takes no power, is quick and cheap to build, requiring only channeling and track carving, and the cart goes up fast, but not so fast that it launches its contents.

Example of an impulse elevator:

{{diagram|spaces=yes|\
z +0 z +1 z +2 z +3
░░░░░ ░░░░░ ░░░░░ ░░░░░
░╔░░░ ░▼╚╗░ ░░▼▼░ ░░░░░
░╝░░░ ░▼░░░ ░░░╔░ ░░░▼░
░▼▼░░ ░░░░░ ░░░╝░ ░╚╗▼░
░░░░░ ░░░░░ ░░░░░ ░░░░░

░ : Wall
╔,╚,╗,╝ : Track/Ramp
▼ : Down Ramp (empty space)
}}

A sort of opposite effect to impulse ramps also exists: ramps lacking the proper "up" and "down" connections are treated as flat track, even if they actually go up or down z-levels. This allows building "anti-impulse" slopes consisting entirely of ramps only connected up, which a minecart can travel up forty levels and more, needing no more than a single push.

=== Controlling traffic ===

==== Switching ====

As constructions or tile features, [[door]]s and other furniture can be built on tracks. A [[door]] or [[floodgate]] can be turned on or off by a [[lever]], effectively controlling the flow of automated minecarts. This may be <s>dangerous</s> [[fun]], however.
{{diagram|spaces=yes|\
->
A ════┤≡════ B
┤ : roller pushing to East
≡ : door
}}
The roller pushes the cart east, but until the "departure condition" is fulfilled, the door remains closed and blocks the path.

[[Bridge]]s can also act as tracks, but only if they're lowered or not retracted. This property can enable levers to turn tracks on and off. However, care should be taken to ensure that such bridges are never operated while a cart is on top of them, as the cart will be flung off the track. It's worth noting that it's often faster, and cheaper, to construct large bridges than long sections of constructed track.

A powered track switch can be constructed by building an "inverted" corner as illustrated below.
{{diagram|spaces=yes|\
B B
║ -> ║
║ ║
════╚═══ ════├════
A C A C
├ : roller pushing to West.
}}

If the cart is pushed East from the stop at 'A' while the roller is activated, it will arrive at 'B'. If the roller is not running, it will arrive at 'C'. The switch works by the roller first reversing the incoming cart's movement and the cart ''then'' following the track corner.

This switch is very reliable, reacts instantly to on/off signals, and carts of any speed can be switched by this design, although very fast carts will require rollers that are several tiles long, up to three. The requirement for power can be inconvenient or impractical. Non-powered solutions may use controlled derailment, or a connecting bridge.
{{diagram|spaces=yes|\
B ╥
║
║
╞════╝ ════╡
A D C
}}
Here the track between A and C is not continuous. The only continuous track is A->B, with a corner (not a T section). Fast moving carts will tend to derail at D and rejoin the track to C. Placing a door at D will prevent the derailment, so the cart continues to B. The door is operated by mechanisms elsewhere (typically, a lever, but some fun can be had with pressure plates).

Since it depends on derailing, this switch requires a very fast cart, faster than what can be achieved with rollers alone. To gain sufficient speed, a cart must be accelerated further, usually by descending several levels or through impulse ramps. The high speed makes the cart much more dangerous and harder to control.

If carts are moving too slowly to derail at the corner, a retractable bridge may be used as a connector between A and C.
{{diagram|spaces=yes|\
B╥
║
║
A╞════bbb════╡C
}}
The bridge must overlap the corner. Bridges behave like a track crossing, allowing carts to pass in a straight line. When retracted, the corner reappears, so the carts will continue to B. Bridges take 100 steps to react to a signal, necessitating rather long "lead times" when switching tracks via bridge.

As mentioned above, special care must be taken to make sure the bridge doesn't change state while the cart is passing over it. Retracting bridges will throw the cart, causing it to stop dead. Raising bridges can even crush the cart.

==== Controlling Speed ====


Minecarts can reach extremely high speeds, especially when descending multiple Z-levels. A minecart will derail at a track corner if its speed exceeds 0.5 t/st (tiles per step), '''unless''' the route in the direction of travel is blocked:

Will derail at > 0.5 t/st:

{{diagram|spaces=yes|\
in ══╗ -> derailing
║
out
}}

Will not derail at > 0.5 t/st:
{{diagram|spaces=yes|\
in ══╗O
║
out

O : wall/column.
}}

This behavior can be used to build a "speed limiter", that will ensure that when a minecart exits it is traveling below derail speed:
{{diagram|spaces=yes|\
░░░░ ░░░░░ ░░░░░
in ═╔═╗░ ░╔S╗░ ░╔S╗░
out ═╬═╝░ out ═╗═╝░ out ═╗═╝░
░╚S╝░ ░╚═╝═ in ░╚S╝░
░░░░░ ░░░░ ║░░░
in
░ : wall
S : Track Stop (High Friction or lower)
}}
If the minecart is traveling below derailment speed, it will not be affected; if above, will be slowed down and checked again. Granted, you could do the same just with track turns, but it may take a lot of turns and time.

Since all the derailings, bounces and ramps can impart a sideway component of speed small enough to start visible drift many tiles away (say, [[Fun|in the middle of a bridge]]), track turns have one more use: forcing the carts to move strictly along the grid directions. Carts passing a turn below derailing speed convert one component of velocity into another, thus eliminating the drift.

=== Loading liquids ===
[[Water]] and [[magma]] can also be loaded into minecarts by submerging them to a depth of at least 6/7 while standing still or moving at speeds of at most 10000. Loading fluids onto minecarts can be difficult because the added friction provided by fluids can stop a cart in a submerged tile. Curiously, filling a minecart with magma does not injure a dwarf ''riding'' it. A minecart will hold enough fluid to increase the depth of a single tile by 2. This amount is listed as 833 units, which weigh 459Γ (water) or 999Γ (magma). An iron or steel cart filled with magma weighs 1313Γ, while an adamantine cart filled with magma weighs 1007Γ. Since you need a minecart above the liquid's level, possible arrangements may include pressure-activated sluices, rollers (with magma-safe chains for magma), pouring from above to "submerge" it briefly on the same level and drain excess away (dig deeper and leave a vaporizer, though if you could have power for rollers, may as well use a pump) and exploits with ramps (not necessarily impulse ramps, "same height" passing dip does it).
The liquids can be dumped by a constructed track stop.

== Quirks ==
This little quirk concerns dwarf-managed minecarts. If a track which was previously open becomes blocked (ex. flipping a switch connected to a floodgate you've built on the track to raise it) and the conditions for departure are met, instead of refusing to ride/guide the minecart or ride/guide it until it reaches the obstacle, the dwarf will pick up the minecart off the tracks and haul it to its scheduled destination on foot. If the distance is long enough and the weight of the cart heavy enough (due to being filled with heavy items such as stones), the dwarf may drop the cart because of fatigue/hunger/thirst before reaching the destination. This will cancel that vehicle setting job and make another dwarf come by and attempt to haul the cart to the nearest appropriate stockpile where another dwarf will pick up the cart and attempt to haul it to its initial stop. If the stockpile is far enough from initial stop, this second dwarf who is attempting to place the minecart on its tracks may also drop the minecart out of fatigue/hunger/thirst creating a loop that will go on until a dwarf with enough endurance manages to place the minecart where it belongs.

In fact, it seems dwarves are more than happy to attempt to carry a minecart from one stop to another even if just waiting until the track is open again would be the more sane option.

Dwarves will also carry a minecart to its next stop if the direction specified is incorrect (or invalid). This can often occur when using the default departure settings and forgetting to set the direction of each condition.

Dwarves can admire buildings while riding mine carts. Dwarves will not fall asleep during a ride (at least not from being drowsy). If riding on a continuous powered track loop, the dwarf will die of dehydration/starvation as they can not jump off to get sustenance{{cite forum|109460/3377228}}. Dwarves riding in submerged minecarts will gain experience in [[swimming]].{{cite forum|129889}}

Tracks block wagon access to trade depots, unless they're on a ramp. [[Bridge]]s can also be used, as they function as tracks but do not block wagons.

== Physics ==


Minecart physics depend greatly on the departure mode set in the route stop conditions.

When set to "Push" or "Ride", minecarts will move according to the regular laws of momentum, gaining speed when going downhill, losing it slowly due to friction when on a flat plane, and more quickly when going uphill. In these modes, minecarts will move in a straight line until they either are brought to a stop by friction or an obstacle, or until they encounter a turn. A minecart will roll straight past "blocked" ends of T-junctions or track ends, they have no power to restrict a cart's movement. The cart's behavior is largely independent of the weight of its contents (including fluids and dwarves): heavily loaded carts gain more momentum when accelerating, but this only plays a role in collisions: a heavy cart gains just as much speed and is as easy to stop as a light one. In either case, dwarves can not push nor ride an unpowered cart up a ramp, bouncing back the direction it came. At best, this is a waste of time; at worst, it will give your cart-pushing dwarf a [[fun|fun surprise]]. To solve this, the player can either use Rollers (see below) or set the cart to be Guided.

The difference between "Push" and "Ride" is whether the dwarf will go along with the cart or not.
{{DFtext|Push}}: the dwarf will give the cart an initial push, not enough to go up a ramp, but enough to go some way along flat track, and the dwarf will remain at the first stop, ready for a new job.
{{DFtext|Ride}}: the dwarf will give the cart the same initial push and then hop aboard the cart riding with it to the next stop.
{{DFtext|Guide}}: minecarts seem to ignore all laws of physics. That is:
*Ignore the weight of any and all items inside. Therefore:
**Move at the speed of the dwarf that is guiding them. It is thus recommended to pick the most [[attribute#Agility|agile]] of your dwarves for cart-guiding tasks.
*Ignore working rollers.
*Will ''not'' collide with other guided carts even when a full frontal collision would be expected.
*Will go up ramps like nobody's business.
This is therefore the recommended method of transport for simple non-powered rail systems, despite it diverting a dwarf from other, potentially more important tasks.

Some samples with behavior:
{{diagram|spaces=yes|\
A <-> B A <-> C A <-> B
B B B
║ ║ ║
A══╝ A══╩══C A══╬╗
You can only go A->B ╚╝
Works when the cart Works
is in Guide mode.
}}
In the second example above, a cart "pushed" from B will go over the junction and roll off into the unknown south.

=== Track Direction Irrelevance ===
Carts that are traveling independently, (that is, not guided,) only care that tracks ''are'' on the tile, not which direction the tracks actually move. Tracks respect only curves (with two exits) and ramps.

This means, for example, that the following tracks, when a (non-guided) cart travels from West-to-East, are functionally identical in effect:

A════════════B A╬║╚╔╣╩╦╠╥╨╞╡B

This is because so far as the cart is concerned, only ramps and curves with two exits where the exit in the path they are traveling matters.

Carts only check for curves when they are halfway through a tile. When they get there, they look to see if their path has no exit. (That is, if it is traveling East, it checks if there is an East exit.) If there is, it ignores all other track directions, and keeps traveling. If there is not, it checks to see if there are only two exits to the track, and if one of those directions was the direction it "came from". (That is, if traveling from the East, it checks if there is a valid exit to the West, and if so, if there is either a North exit or a South exit.) If there is not, it ignores the track anyway, and keeps on traveling as though it were still on track. If there is, it will subtract 1000 from the velocity of the cart, and redirect all forward velocity to the direction of the curve. This change in the direction of velocity ''overwrites'' any "diagonal" velocity, which can prevent diagonal velocity derailments, but any perpendicular velocity is not preserved, and is instead discarded.

=== Skipping ===
If a minecart is moving fast enough, it can skip over [[water]] or [[magma]], making splashes of [[mist]] (or [[magma mist]]) as it attempts to move on them horizontally. This horizontal movement is independent of the minecart and its content's [[weight]].

=== Track Jumping ===
If a minecart encounters the end of the track or a T junction with no "exit" in its movement direction, it will simply leave the track and continue on its course in a straight line until it encounters an obstacle, slows to a stop, or encounters another (properly aligned) Track even if the tile at which it joins the new track instantly sends it around a corner.

Tracks that are travelling at high enough velocity will also start "jumping" the track if it hits an un-tracked tile (flying over and ignoring any tracks) until it is ready to land. Carts that land upon tracked tiles re-rail themselves, and clever designers use this feature to jump over curved track sections in one direction or another. (Retracting bridges over untracked tiles can cause jumps or not cause jumps depending upon the status of the bridge.) Minecart speed must be carefully regulated to ensure reliability of jump length.

Carts that approach a downward slope at a high enough velocity will also make a jump, but will not do so if the Checkpoint Effect (below) is exploited through an impulse ramp before the actual downhill as the impulse ramp "tricks" the cart into thinking it has already started going downhill.

=== Invalid Ramps ===
Ramps are functionally defined for cart purposes as being a tile which exerts an acceleration force upon its "downward slope". This downward slope requires a cart to have one ''and exactly one'' carved exit to the tile that is the "bottom" of the ramp. Ramps push carts in this "downward" direction (possibly leading to diagonal movement, below), and the deceleration of an "uphill" ramp is actually just the acceleration being applied against the direction of a cart's movement.

This is where players can find an exploit in the behavior of ramps - if there are ''two'' "downhill" exits to a ramp (such as a "T junction" on a ramp where only one exit faces a wall), then the ramp provides no acceleration ''or'' deceleration, allowing carts to travel up ramps without any loss of momentum except for the standard "flat track" deceleration, because as far as the cart is concerned, the track ''is'' flat.

Similar effects can be achieved when there are ''no'' "downhill" exits to a ramp. This may be the case if you have, for example, an East-West track with a one-tile channel with a ramp in it. The cart will travel through the "dip" with no change in velocity. It can also be the case if you abuse the Track Direction Irrelevance, above, and set only exits ''up'' the ramp, and none leading ''down'' the ramp. For example, if a cart is traveling from West to East up a slope, only carving East exits on each tile of ramp will make the cart travel up the ramp, and then recognize the tile it is on as being a "flat" tile, thus ignoring any deceleration from traveling uphill. Note that this effect only reliably occurs at relatively slow speeds (at around push, or single accelerating ramp speeds) as the cart may simply ignore the ramp and crash into the wall at higher speeds.

=== Corner Ramp Derail ===

Corners on upward ramps can cause diagonal movement, forcing a derail even if the cart has a wall next to it, which will force a stop when it touches a wall that forces dwarves to manually reset the cart.

This is caused by the fact that a cart, after turning the bend in the track halfway through the length of the tile, will still "accelerate down", which is now perpendicular to the movement of the cart, causing acceleration to occur in two directions. (Down corner ramps do not have this problem, as when they pass the halfway point, all perpendicular motion is added to forward motion, and after that curve, all downward acceleration is in the forward direction.)

There are two fixes to this problem. One is to simply not put corners on up ramps. The other is to take advantage of the Checkpoint Effect, below, by making a ramp (possibly including an impulse ramp) one tile in front of the ramp to make it skip through most of the tile before sideways momentum can be built.

=== Checkpoint Effect ===
The checkpoint effect, [http://www.bay12forums.com/smf/index.php?topic=144328.0 explained in depth by Larix], is an odd and highly exploitable feature of ramps where minecarts "teleport" through the next tile of track, ignoring nearly all minecart physics (except that they stop at all walls or other obstacles and not only respect curves, but will take them even when they would otherwise derail) and passing through that tile in just a single tick, and into the next tile at the halfway point.

This effect occurs when a cart leaves a downward ramp for any other direction of tile. (This includes ramps which accelerate in different directions, even a ramp which goes from accelerating East to accelerating North due to a bend in a chain of standard down ramps in a curve.) This allows, for example, two valid straight ramps directly next to one another with a cart dropped onto one or the other with no momentum to have the cart pick up acceleration going "down" the ramp as normal, but then flying up through the "up" ramp it travels into with no loss of momentum, as though it had come from an impulse ramp. If the two ramps had at least one space of distance between them, and then a cart were dropped in, the cart would instead "rock" back and forth between the two ramps.

This seems to be because ramps have a slightly longer length than regular tiles - 144,000, rather than 100,000 distance. When this "snaps back" after a ramp, it seems to project the cart suddenly further along the track, making it jump a tile ahead even when otherwise moving at relatively low speeds.

This effect would be a "[[bug]]" if it weren't probably deliberately coded, and an "[[exploit]]" if it weren't impossible not to feel its effects. Nevertheless, many designs exploit the checkpoint effect to allow "perpetual motion devices" where a cart stuck between two ramps can climb a ramp with no loss in momentum, creating unpowered perpetual motion devices. This also allows for ramp "elevators" to be constructed even without impulse ramps (although impulse ramps make it more compact, still).

Another useful thing to note about this exploit is that carts traveling at no less than 72,000 or so speed (enough to travel half a ramp tile in a single tick) can travel through every tile in just one tick at no change in velocity as long as the tiles alternate between impulse ramp or actual down ramp and any other tile type. The cart checkpoints through the non-down-ramp tiles, and can pass through the (impulse) down ramp tiles in a single tick, before they can actually start gaining momentum.

=== Falling ===
When falling, a minecart appears to cause no damage upon collision, possibly to allow cart "stacking" across Z-levels.{{cite devlog|2012|04|06}} A dwarf riding in a minecart that is dropped multiple z-levels suffers normal fall damage. Minecarts can fall through up/down stairs.
The cart falling (from a hatch, thus with no horizontal speed) onto a track ramp is accelerated as if starting from the middle of the ramp - i.e. to the same speed, no matter how many Z-levels it was dropped, vertical velocity is negated. {{cite forum|144328/5701211}}

=== Stacking ===
If a minecart lands on top of another minecart, they may form a stack, with the upper cart on the z-level above the lower. Subsequent carts do not form a stack, but rather quantum stockpile in the same space. This behaviour is useful for [[megaprojects]] and [[trap design]] with minecarts as the weaponry. Moderation should still be exercised: carts take longer to fall into a "stacking" tile already occupied by other carts and will spend that time "hanging" in the air above the stack. This can lead to following carts striking them, which can cause all kinds of malfunctions. The extra time is two game steps for every cart already in the stack, which doesn't hurt stacks of ten carts very much but makes stacks of 100+ rather impractical.

These minecarts on the upper level generally need to be struck with another minecart to move out, or have their support removed. The latter option is safest done by shooting it away with another minecart, manual removal of a stack-supporting cart typically causes the next cart from the stack to [[fun|fall on top]] of the hauler.

=== Perfectly Elastic Collisions ===
Minecart collisions are perfectly elastic, meaning that not only do minecarts not take damage, but that two carts that are rolling which have frontal collisions of near-similar speed, and where one cart is no more than twice the mass of the other cart, will result in a billiard-ball-like effect of the lighter cart bouncing off the heavier cart with a proportional speed increase dependent upon the relative momentum behind the heavier cart.

Using this trick with carts already at the 270,000 maximum speed from ramps can result in "supersonic" carts traveling at speeds in the millions (travelling a dozen tiles per tick), but where they are suddenly subject to 10,000 units of "terminal velocity" friction per tick. [http://www.bay12forums.com/smf/index.php?topic=137557.0 Thread with SCIENCE here].

While hypothetically capable of launching a minecart into orbit when used in conjunction with a ramp, no cargo can be contained in the launched cart, as the collisions will force ejections of the cargo. Your "unwilling volunteer" [[goblin]] space pioneers will simply become paste underneath the wheels of an extreme high-speed cart.

=== Numbers behind the scene ===

According to early research by '''expwnent'''{{cite forum|112831/3536975}}:

The minecart has a variable for speed. Speed is measured in tiles/100000 ticks, so a speed of one hundred thousand means one tile per tick. By going down a large number of ramps, a maximum speed of 270,000 can be reached, which presents the limit for most practical applications. Short bursts of (much) higher speeds are possible through carefully planned collisions of high-speed carts {{cite forum|137557/5145499}}.

Every tick the cart accumulates distance units, as well as slows down depending on current tile (speed is reduced by "friction" of the tile). The cart will move to the next tile the tick before accumulating 100000 distance units, (or several tiles in case of great speed), then the leftover distance units are added to the default 100000 distance u. of the next tile. Since most deceleration and acceleration is applied per step, with the notable exception of corners, a cart going at twice the speed of another one can cover about four times the distance in a straight line, but only twice the distance along a winding track with very many corners.

A push will teleport a cart to the beginning of the next tile (NOT the middle!) in one tick with 19990 speed (10 speed is lost due to track friction), while a roller will give a cart the roller's set speed, and it will start to accumulate regular track friction past the middle of the roller tile. Some track features will affect a minecart when it is past the middle of the previous tile: entering a ramp or a hole/drop will happen when the cart has left the middle of the previous tile, and the ramp will gain additional distance unit depending on the leftover units from the previous tile. When a cart leaves a ramp it will emerge after one tick in the middle of the next regular tile, so its entry coordinate is "50000-speed+friction". Rollers also affect the speed of minecart from the middle of the previous tile.

Friction of tiles:
{| class="wikitable"
|-
! Tile
! Friction
! Comment
|-
| Tracks
| 10
|-
| Ground/Floor
| 200
|-
| Unusable ramp
| 10
|-
| Upwards ramp
| 4910 (10+4900)
|-
| Downwards ramp
| -4890 (10-4900)
|-
| Roller
| ±100000 (but capped by the set speed)
|-
| Corner track
| 10
| Speed reduced by 1000 upon leaving the corner tile
|-
| Track stop (highest)
| 50000
|-
| Track stop (high)
| 10000
|-
| Track stop (medium)
| 500
|-
| Track stop (low)
| 50
|-
| Track stop (lowest)
| 10
|-
| Water 1-6
| Additional (WaterLevel - 1) * 100
| rowspan="2" | [[#Skipping|See Skipping]]
|-
| Magma 1-6
| Additional (WaterLevel - 1) * 500
|-
| Empty space
| 0
|}

Water of depth 7/7 provides a friction of about 10000 per step, as does maximum-depth magma. This higher friction may not apply to very slow-moving carts.

Impulse sources:
{| class="wikitable"
|-
! Feature
! Speed
|-
| Push
| 20000
|-
| Roller lowest
| 10000
|-
| Roller low
| 20000
|-
| Roller medium
| 30000
|-
| Roller high
| 40000
|-
| Roller Highest
| 50000
|-
|}

== Non-standard uses ==
Minecarts include some interesting characteristics that have motivated uses beyond hauling. They can be useful for creating fully-automated [[exploit|quantum stockpiles]] and [[garbage disposal]]s. Storing perishable goods (meat, meals, etc.) inside a minecart appears to guard against rot and vermin.
Minecarts can be [[Trap_design#Minecarts|used as weapons]], or as (hopefully non-fatal) triggers to restart stalled [[healthcare]]. They can also be used to time/control game events, either using a basic [[repeater]] or much more advanced [[minecart logic]].
Minecarts trigger [[pressure plate]]s, which means a trap can be designed to trigger when a thief attempts to steal a minecart.
A pressure plate can be used as automatic and more precise custom "launch when full enough" system - as long as weight of your minecarts stays the same. You cannot build a hatch or roller on the same tile, so launch by bumping with another cart. {{cite forum|15096/4580050}}
Dwarves riding minecarts can attack enemies within reach (which goes back to dev log). This applies to shooting, and they actually can hit targets while riding by.{{cite forum|109460/5266119}} Whether a minecart protects the rider and how it interacts with dodging is not known yet. Minecart riders can also [[Swimming#Minecart_training|train swimming]] and [[Megaprojects#Surveillance_Track|detect ambushers]].

== Adventure mode ==
In addition to being used for hauling, minecarts can also be ridden in [[adventure mode]]. (Adapted from forum thread {{cite forum|122903/4258212}})

# If the minecart is in your inventory, drop it. If it is already on the ground, proceed to step 2.
# Press {{k|u}} when you are 1 tile away from the minecart (or standing on the same tile as the minecart).
# You will be presented with the following options:
[[File:minecart adventure mode menu.png|left]]
{{clear}}
* If you {{DFtext|Push}} the minecart, it will move a few tiles in the direction you chose. Physics comes into play here, so it will gain/lose speed depending on the usual factors.
* If you {{DFtext|Ride}} the minecart, you will hop into the minecart, even if you were a tile away, and it will move in the chosen direction with you in it. It will gain/lose speed depending on the usual factors. Whilst the minecart is in motion, you should press {{k|.}} to skip your turn; if you attempt to move whilst the minecart is still in motion, the laws of physics come into play, and you will take [[wound|damage]]. Alternatively, you can push the minecart whilst it's still in motion (although it's unclear how one can bend [[physics]] so as to push a moving minecart whilst inside the minecart). If you push it in the same direction you are already travelling in, you will greatly increase the minecart's velocity. You can also push it in different directions, and this will cause it to gradually change direction-the amount of pushes this requires depends on the minecart's velocity. Once the minecart has stopped moving, you may move out of it safely, or you may want to give it another push. Note that if you push a minecart right after having ridden it (still on the same tile as the minecart), it will act as though you chose to ''ride'' it.

If you want to test this out without creating an adventurer, the [[object testing arena]] allows you to spawn minecarts ({{k|k}}-{{k|c}}-{{k|n}})

== Forging and Melting ==
* Metal minecarts cost '''two''' [[metal]] bars to forge, or '''six''' [[adamantine]] wafers.
* When a non-adamantine metal minecart is melted down, it will return '''1.8''' metal bars, for an '''efficiency of 90%'''.
* When an adamantine minecart is melted down, it will produce '''1.8''' wafers, for an '''efficiency of 30%'''.

== See also ==
* [http://www.bay12forums.com/smf/index.php?topic=109460.0 The "How Does Minecart" Thread] by '''Girlinhat''' et al.
* [http://www.bay12forums.com/smf/index.php?topic=112831.0 SCIENCE: Quantifying minecart physics] by '''Snaake''' et al.
* [http://www.bay12forums.com/smf/index.php?topic=129676.0 How to build a Multi-cart Ore to Magma Minecart Project without needing power] by '''WanderingKid'''.
* [http://www.bay12forums.com/smf/index.php?topic=144328.0 My very own Minecart Education Thread. Ten Lessons, now complete.] by '''Larix'''.

== Bugs ==
*A dwarf will drop her [[child|baby]], if she has one, when boarding a minecart set to be ridden.
*Dwarves have no concept of traffic safety and will walk into busy minecart lines to retrieve objects, often with deadly consequences. This is especially problematic in [[Swimming#Minecart_training|clever applications]] depending on dwarves riding the carts very frequently, because they have a bad habit of dumping their worn clothes on the tracks after a minecart ride. Adding an automatically-operated [[hatch cover]] at the end of such a ride can help prevent [[unfortunate accident]]s.
*Dwarves cannot guide a minecart through an unlocked door unless another dwarf opens the door.{{bug|6056}}
*It is possible for a creature and minecart moving towards each other to pass without collision if they exchange tiles in the same tick.
*After a minecart ride, a dwarf will sometimes haul the minecart to a storage stockpile, leaving another dwarf to haul the vehicle back to the route.
*Minecarts falling onto a floor injure creatures in the tile below the floor.{{bug|6068}}
*A minecart's initial velocity is not affected by weight, when pushed or launched from rollers.{{bug|6296}}
*Removing a stop that has a vehicle waiting on it may cause the game to crash.{{bug|5980}}

{{Category|Fortress mode}}
{{Category|Interface}}

[[ru:Minecart]]

Minecart

2015-06-18T01:55:24Z

NW Kohaku: /* Physics */

{{Quality|Masterwork|08:15, 19 May 2015 (UTC)}}
{{av}}
A '''minecart''' is a [[tool]] intended for [[hauling]], introduced in version 0.34.08. It can be made of [[wood]] at a [[carpenter's workshop]] or [[metal]] at a [[metalsmith's forge]] (using the [[Metal crafter|metalcrafting]] labor.) Minecarts store up to five times as many items as [[wheelbarrow]]s and are quite a bit faster than dwarves hauling objects by hand, but have the disadvantages of requiring a dedicated track network, a complex route planning phase, and the possibility of dwarves [[Fun|blundering into the path of carts filled with lead ore]]. Tracks may be carved into stone, or [[Construction|constructed]]; the latter allows above-ground routes, but these are more difficult to set up due to their additional [[building material|material requirements]].

Just like wheelbarrows, minecarts are considered [[item]]s and are stored in a [[furniture]] [[stockpile]]. Despite their five-times-greater capacity, they are only 33% larger than wheelbarrows and are identical in base [[item value|value]] when made from the same [[material]] (the value may differ due to the [[item quality]]). [[thief|Thieves]] or even mischievous animals can steal minecarts, even when they are moving on a track{{cite forum|109460/3289070}}. However, minecarts moving fast enough or being ridden cannot be stolen.

Although most of the utility of minecarts is in [[fortress mode]], an [[adventure mode|adventurer]] can also ride in a minecart. Adventurers can also pick up and relocate minecarts.

The invention of minecarts revolutionized the [[minecart logic|Science of Dwarfputing]] by enabling smaller, faster logic systems to be built.

== Basic Minecart Usage ==
Minecarts can be used to swiftly transport dwarves, [[flow|fluids]], and/or large amounts of items, but before you have a functional minecart there are several preconditions that need to be met. First of all you need an actual minecart, constructed either in a [[carpenter's workshop]] or [[metalsmith's forge]]. For the minecart to be able to move you also need to carve (with {{k|d}} {{k|T}}) or construct (with {{k|b}} {{k|C}} {{k|T}}) a track, which could be as simple as a straight line. Finally you need to construct stops on your track (with {{k|b}} {{k|C}} {{k|S}}) where the minecart will start and stop.

After you have created the stops and assigned a cart to the track, you must create logic routes connecting several stops and designate starting conditions for each stop. This is done with the {{k|h}}auling key. The most basic conditions are how the cart's movement is initiated and in which direction the cart should start moving. Carts can be either be Pushed (a dwarf stands at a stop and gives the cart a single push) or Guided (a dwarf continually pushes the cart forward, guiding it along the track). The [[hauling]] [[labor]] required for pushing and guiding carts is called "Push/Haul Vehicles" and is turned on by default.

To control which items to transport you can add conditions specifying: (1) which kind of items to be loaded, and unloaded, (2) stockpile links to define which stockpile(s) the items should be un/loaded to and from.

===Capacity and weights ===
Minecarts have five times the [[Weight|capacity]] of [[wheelbarrow]]s.

'''Examples of the capacity of one cart'''
{| class="wikitable"
|-
! Item
! Amount
|-
| [[stone]]
| 5
|-
| [[wood|log]]
| 10
|-
| [[block]]/[[bar]]
| 83
|-
| [[Kitchen|prepared meals]]
| 500
|-
| [[Trap_component#Spiked_ball|spiked balls]]
| 500
|-
| [[Weapon#Native_weapons|mace]]
| 625
|-
| [[Weapon#Native_weapons|spears]]
| 1250
|-
| [[cloth]]
| 2500
|}

The weight of the loaded minecart does not affect the initial velocity received from pushing or launching from a roller. However, the load of a minecart ''does'' affect whether a [[pressure plate]] triggers or not, based on the pressure plate's setting.

'''Weights of different carts'''

{| class="wikitable"
|-
! Type of cart
! Empty cart
! Fully loaded (items)
|-
| oaken minecart
| 28Γ
| 378Γ (10 oak logs)
|-
| platinum minecart
| 856Γ
| 10482Γ (83 gold bars)
|}

The weight of a minecart is one twenty-fifth (1/25) the [[density]] of its material in Urists. Because pressure plates can be set to trigger at intervals of 50 Urists, minecarts with weights just under a multiple of 50 are ideal for switching based on whether they're full or empty. The best minecart materials for full/empty switching are as follows:

{| class="wikitable sortable"
|-
! Material !! Minecart weight !! Content weight required to trigger !! Banana roasts required to trigger (for scale)
|-
| [[Bismuth]] (moods only) || 391 || 9 || 15
|-
| [[Brass]] || 342 || 8 || 14
|-
| [[Electrum]] || 596 || 4 || 7
|-
| [[Fine pewter]] || 291 || 9 || 15
|-
| [[Glumprong]] || 48 || 2 || 4
|-
| [[Lay pewter]] || 291 || 9 || 15
|-
| [[Nickel silver]] || 346 || 4 || 7
|-
| [[Tin]] || 291 || 9 || 15
|-
| [[Trifle pewter]] || 291 || 9 || 15
|}

=== Creating tracks ===
Minecart tracks are made up of contiguous track, tracked ramp, or bridge tiles. Track tiles and tracked ramp tiles have a direction or series of directions associated with them. These directions dictate which directions a minecart on a given tile may move from that tile. For example, a Track NE (northeast) tile allows a minecart on it to move either north or east from its present position. Therefore, if you want your minecart to move east along a straight piece of track, then return west using that same track, you would need to use EW tracks so that the cart could travel east initially, then return west over the same track. Excluding designs in which the cart will "jump" tracks via a drop or other ramp, tracks must be valid end to end to work for most looped or straight-track applications. A single east only track tile in your line of east-west tracks will cause any route using the track to fail the moment it tries to go the wrong way over that tile. Minecart tracks can be built in two ways: Engraved/carved or constructed. A given minecart track need not use engraved or constructed elements exclusively, as the two methods can be used interchangeably depending on the needs of a given section of track. The way the tracks are built is slightly different between the two, as explained below.

====Simple tracks====

'''Carved'''

A single-tile wide strip of natural stone can be designated to be [[Engraver|carved]] (with {{K|d}} {{k|T}}), which will create a straight two-way track. The creation of corners, crossings, and T-junctions is as simple as designating another strip of track that overlaps an existent or newly designated track. Engraved tracks are removed by [[smoothing]] the rock they're on, which results in a smooth floor (that can be re-engraved if necessary), or by building a [[floor]] on top and subsequently removing it. Dwarves can carve corner tracks in one pass by designating the track carving twice and canceling unwanted carvings (with {{K|d}} {{K|x}}). Tracks can be engraved in any natural floor tile, rough, smooth and even over engravings, providing an easy method to remove low-quality or undesired floor engravings. Once a track has been engraved, it's important to check the track directions for each tile in the route carefully to make sure no mistakes were made by yourself or the game's track engraving logic.

'''Constructed'''

Tracks can also be built as regular [[construction]]s (through {{K|b}} {{K|C}} {{K|T}}). This method is resource-expensive, since each track tile requires one stone, [[bar]], or [[block]] for construction, and time-consuming, since you can't designate strips longer than 10 tiles at a time. Corners, crossings, T-junctions, and ramps also have to be designated individually. However, it is usually the only way to build tracks above ground or on soil (barring the [[Obsidian farming|creation of obsidian]]). Constructed tracks are designated for removal like any regular construction; be aware that removing track ramps built on top of natural ones will also remove the original ramp, leaving a flat floor.

====Ramps====

'''Carved'''

The carving of natural ramps is a little more confusing: to carve a two-way track on a ramp (natural only, does not work on constructed ramps), you must designate the track '''starting on the ramp and one square beyond''' in the direction you want the track to go. For the side of the ramp square you want to head upward, there '''must''' be either a natural or constructed wall in the square next to it, otherwise the game assumes you are trying to carve it on the same level -- this can result in the track being carved underneath a door or other object. If you have accidentally done this, you can correct it by smoothing the ramp and constructing a single square of wall next to it, then re-carving the ramp correctly. (However, the wall must stay there permanently; removing it will disconnect the track.)

'''Constructed'''

When constructing track ramps, the stated direction should be the same as the connected tracks. For example, a track going up from West to East would require, starting from the West, a Track (EW), a Track/Ramp (EW) and a Wall behind the ramp, underneath the section of track above it. Incorrectly placed ramps result in minecarts ignoring the ramp and crashing into the supporting wall. They will not, however, display as unusable as when the supporting wall is missing.

'''Examples of ramps'''

A simple ramp would look like this:
{{diagram|spaces=yes|\
z +0 z +1
░░░░ ░░░░
═▲o ░▼═
░░░░ ░░░░
o : wall
}}

Carving track corners into ramps is rather unintuitive and complicated. Since engraving tracks always requires two tiles to connect in a straight line as input, you have to give two separate designations for a single job: a track bit from the ramp tile to the "below" direction and another one to the wall of the "upward" direction. If you wanted to change direction on a ramp from east to north:
{{diagram|spaces=yes|\
z +0 z +1
░░░░░ ░░░░░
░░░░░ ══╗░░
=▲░░ ░░▼░░
░░░░░ ░░░░░
}}
you would need to connect the ramp on z +0 both to the west and to the north by issuing two "carve track" commands, one selecting the ramp and the track tile to the west, and another connecting the ramp tile with the wall to the north. An engraver would then carve a NW track corner into the ramp, allowing carts to pass the corner correctly both going up and down. Such track corners are perfectly serviceable for guided carts, but moving down a route of several of them by pushed or ridden cart is problematic - ramps on corners behave very counter-intuitively, resulting in loss of speed when going down and diagonal movement when going up.

Moving to and from ramps (or between ramps "pointing" in different directions0 causes some non-trivial adjustments to speed and even moving along the tiles at a fixed speed ''unrelated to the entry/exit velocity values'', because transitions to/from ramps are processed differently and are not to be "skipped". This affects compact track/ramp combinations (such as e.g. a simple 2x2 ramp spiral) most, and combined with bouncing often makes them work not in the way one could expect. {{cite forum|144328/5705102}}

{{anchor|Tracks}}

=== Hauling route ===
A hauling route is a list of directions describing how and under what conditions a minecart will move. The proper setting up of routes is essential for a working rail system. Routes, stops, departure conditions and stockpile links are managed from the {{k|h}}auling menu.

==== Route ====
A route defines the path a minecart will take along a track, as well as under what conditions it will move or stop moving. A route is made up of stops. Stops are precisely what they sound like, a position on the track at which you want a minecart to stop. A minecart track might use as little as a single stop for a looped track, which will serve as both a starting and stopping point for the cart, or it could contain many stops, perhaps to load supplies or wait for a bridge to be manually lowered, before reaching its destination or returning to its starting point. It is important to note that you only need to place stops on a route where you actually want the cart to stop and wait for some action to occur. They are not needed to help navigate the cart along the track beyond telling it where on the track to stop.

New routes are created with the {{k|h}}auling key. Existing ones can be removed (without confirmation) with the {{k|x}} key, and also {{k|n}}icknamed. Before operating, the route must have a {{k|v}}ehicle assigned to it (this can be done with either the route or a stop selected). Assigning a full minecart to a route may result in a slow hauling job if the contents are heavy.

==== Stops ====
Stops are the individual waypoints that make up a hauling route. A given stop consists of the location of a tile, as well as conditions describing when, where, and how a cart should be moved after being stopped at that tile. Stops can be created from within the {{k|h}}auling menu, by placing the cursor over a tile and hitting {{k|s}} while highlighting the route (or a stop within) you've already designated. A minecart will begin its route at the first stop created, and continue through each subsequent stop, being guided, pushed, or ridden from each stop to the next depending on the conditions specified. In many basic minecart applications, the cart will end up at the same stop it began at, though this is not always the case. It is important to note that hauling stop order is enforced, even if there is no track. A dwarf will drag the cart overland back to a skipped stop in the route's list if your tracks bypass it somehow.

Once a stop has been placed, it is given a default set of conditions under which to move the minecart if it is stopped there. Each new stop gets the same default conditions regardless of the track it is placed upon (e.g. guide the cart to the north). For this reason new stops might get marked by yellow exclamation marks ({{DFtext|!|#ff0}}) due to invalid directions. One important thing to note is that as you place additional stops, the display will show paths between the stops you have defined. However, this is '''not''' necessarily the actual route the minecart will take once the route is in operation. For example, if a route were defined with two stops at opposite ends of a track with many twists and turns, a line will be drawn directly between those stops to show the order in which they will be visited. These route lines may crisscross all over the tracks, but so long as the track is valid end to end, the cart will follow the track from one stop to the next, even across twists, turns, and z-level changes. Stops, which are the steps that make up a route, should not be confused with Track Stops, described below.

===== Stockpile links =====
By placing the cursor on top of a stockpile and using {{k|s}}, you can create stockpile links while defining a hauling stop. Links can also be redefined by selecting them, placing the cursor over a different stockpile, and pressing {{k|p}}. The cart will then be filled by items present in its various linked stockpiles in preference to other items. Note that bins should be used with caution in stockpiles that are linked to minecarts. Bins cause problems when used with the "Desired Items" list in a stop's conditions. For example, if a minecart is set to accept only granite blocks, and to depart north when it is 100% full of granite blocks, it will not depart if any of those granite blocks are in bins, even if bins are also included in the desired items list. Two solutions to this problem exist as of v0.40.24. First, bins can be disallowed in stockpiles that are linked to stops. Alternatively, bins '''can''' be used in conjunction with minecarts provided that the minecart's departure conditions use only "any items" instead of "desired items." This option can be toggled in the advanced conditions menu for a stop, accessible via the {{key|C|}} key. The cart's contents can still be controlled by specifying what items are allowed in the linked stockpile.

===== Departure condition =====
Departure conditions involve setting conditions in which the minecart will leave on the route. Each condition includes:
# A departure mode (Guide, Ride or Push).
# An initial departure direction (NSEW). Note that this defines the initial direction of movement only. Even if a track includes many turns, as long as the initial movement direction is valid the cart will follow the minecart track thereafter.
# A timer, before which the departure condition cannot be met.
# Conditions on the amount of items in the cart.
Departure conditions are created with the {{k|n}} key. A new departure condition will read: "guide north immediately when empty of desired items". This condition can be changed between basic presets with {{k|c}}. "Advanced" mode ({{k|C}}) allows for more precise control over departure conditions: fine tuning the percentage from 0 to 100 in 25% steps ({{k|f}} and {{k|F}}), switching it being either the maximum or the minimum amount of items for the condition to be met ({{k|m}}), and whether the cart accepts all or only a specific set of items ({{k|l}}). Common to both screens are the departure mode ({{k|p}}, Push, Ride or Guide), {{k|d}}irection, and timer ({{k|t}} and {{k|T}}) options.

To have a cart only carry a specific set of items, the stop can be set to only carry "desired" items, opening the selection screen with the {{k|Enter}} key while having said stop condition selected, and toggling as desired, or it can simply be linked to a stockpile and set to depart once it is full of items from its linked stockpiles, regardless of type.

=== Track Stops ===
A Track Stop, not to be confused with a route stop, is an optional, single-tile construction which serves two purposes. First, it can be used to cancel a cart's momentum in order to slow or stop it as it passes over the Track Stop. This might be necessary if a cart were pushed down a series of ramps to its destination. Second, a Track Stop can cause a cart to automatically dump its contents as it passes over the Track Stop. Track Stops are constructed via {{k|b}} {{k|C}} {{k|S}}, and must be constructed atop an existing piece of track. If a Track Stop has been set to automatically dump a cart's contents, the cart will dump its contents in the direction indicated when it passes over the Track Stop. Depending on the friction settings chosen for the Track Stop, the cart might then stop after dumping, or it might continue on its route to another destination.

Track Stops are not mandatory; in fact, their main use is in automated rail systems. However, even in basic rail systems it can be useful to set a Track Stop to dump items: this saves time that dwarves would otherwise spend in removing items from the cart, time that is better spent driving the cart back to where it's needed. Dumping will occur even with a guided cart. '''Take care not to set Track Stops at a loading site to dump their contents''', or dwarves will never be able to fill the cart. It will dump any contents the moment they are loaded.

Counter-intuitive to their construction method, Track Stops are considered [[building]]s and must be removed by {{k|q}} {{k|x}}.
* See [[#More_on_Track_stop |More on Track Stops]]

=== Step-by-step tutorial ===

Let's construct a simple minecart route. This route will move stone blocks from an input stockpile to an output stockpile. We'll begin by creating the stockpiles:

[[File:minecart-example-1.png|Stockpiles designated.]]

The input stockpile is on the left; the output stockpile is on the right. We'll be moving blocks from left to right. Disable bins in both stockpiles, and set the input stockpile to accept only from links. Then make the stockpile take from the mason's workshop where the blocks are being produced.

Next, carve the track:

[[File:minecart-example-2.png|Track carving designation.]]

Note that the ends of the designation are uniquely shaped; this is automatic, and not anything you need to control. Now, wait for your engravers to come along and carve the track into the stone. (Your haulers will probably also fill up the input stockpile while you wait.)

In addition, while we're waiting for that to happen, we'll build an iron minecart in the forge.

[[File:minecart-example-3.png|Track carved.]]

When the track has been carved, it will look like the above (the track will be solid instead of flashing). Now, order a track stop to be constructed next to the output stockpile:

{|
| [[File:minecart-example-4.png|Track stop designation.]]
| [[File:minecart-example-5.png|Select dumping direction.]]
|}

You must press {{k|d}} three times to select the dumping direction ''before'' placing the track stop. We want our blocks to be dumped into the output stockpile east of the track stop. Then wait for a mechanic to come along and build the track stop.

[[File:minecart-example-6.png|Track stop constructed.]]

Now we'll define the actual ''route''. This is done in the {{k|h}}auling menu. Press {{k|r}} to begin defining a route. Next, move the cursor to the input end of the track, and then press {{k|s}} to define the first stop:

{|
| [[File:minecart-example-7.png|Stop 1 designation.]]
| [[File:minecart-example-8.png|Route definition, in progress.]]
|}

Move the cursor again, to the output end of the track, and press {{k|s}} again to define the second stop:

{|
| [[File:minecart-example-9.png|Stop 2 designation.]]
| [[File:minecart-example-10.png|Route definition, two stops.]]
|-
|
| [[File:minecart-example-11.png|Stops are not defined yet.]]
|}

There are several user interface features to note at this point. The stops have been positioned, but they haven't been ''defined'' yet, so there is a warning {{DFtext|!|#ff0}} symbol by each of them. In the lower right corner, we see what the {{DFtext|!|#ff0}} means. Also, note that the second stop is labeled in white, while the other two lines are grey. The white text is a selection indicator, and can be moved up and down by pressing {{k|+}}/{{k|-}}.

Next we need to define what our stops do. We want the minecart to be filled with blocks at the first stop, then travel to the second stop where it will dump its cargo, and then return. Press {{k|-}} to move the selection up to stop 1, and {{k|Enter}} to open it up. By default, the stop has three conditions:

[[File:minecart-example-12.png|Default stop definition.]]

We don't want any of these, so press {{k|x}} three times to delete them. This leaves us with a blank stop. Now we can add the conditions we actually want. Press {{k|n}} to begin adding the first condition, then {{k|d}} twice to change the direction from north to east. Then press {{k|c}} to change the condition from empty to full. This will instruct the minecart to be guided east when full of desired items.

To set the desired items, we create a stockpile link. Press {{k|s}}, then move the cursor to the input stockpile, then press {{k|p}} to select that stockpile. Now press {{k|Enter}}; this opens up a selection screen that resembles the stockpile customization screen. Move down to Blocks, {{k|e}}nable them, then (if you wish) restrict it to stone blocks.

When you've done all that, stop 1 should look like this:

[[File:minecart-example-13.png|Stop 1, defined.]]

Stop 2 is much simpler. All we need to do is have the minecart return to the input stop. So, make a condition and change the direction:

[[File:minecart-example-14.png|Stop 2, defined.]]

Finally, we just have to assign our minecart. Go back to the route definition screen, and press {{k|v}}. Select the minecart, and press {{k|Enter}}.

Now we've got everything set up:

[[File:minecart-example-15.png|Route, fully defined.]]

The V is red because the minecart hasn't been moved onto the track yet. Some dwarf will have to haul it from the forge to the first stop, by hand; this will take a while, especially if the forge is far away.

Once the minecart is in place, dwarves should fill it with blocks from the input stockpile, which will in turn be filled with blocks from the workshop where your mason has been toiling dutifully. When the minecart is full, the blocks will be dumped into the 1x1 stockpile on the right. Automatic quantum dumping!

=== Troubleshooting ===

Because of the complexity of the system, all but the most careful and experienced minecart users will encounter issues. Most route issues can be diagnosed and fixed from the {{k|h}}auling menu.

'''Symptom:''' {{DFtext|! Set dir/connect track|6:1}} message appears to the right of one or more stops

'''Possible Causes:'''
* The departure direction of the stop might be invalid. Edit the stop using {{k|Enter}} and press{{k|d}} until it is pointing in a valid direction.
* The track stop might not be built on top of a track. The track stop must be deconstructed to remedy this issue.
* Your track might not be built correctly. Make sure all connected tracks between destinations are not one-way tracks.
** This can be especially confusing with ramps. To carve a two-way track on a (natural) ramp, you must designate the ramp and one square beyond in the direction you want the track to go.
** Ramps '''must''' have a solid block on the side opposite to the track, or they will neither work nor be marked as "unusable". The solid block can be natural or constructed.
* The desired/kept items might not be configured correctly.

'''Symptom:''' The status '''0% V''' always appears to the right of one stop.

'''Possible Causes:'''
* The stop may not be set to take from a stockpile. Edit the Stop using {{k|Enter}} and make sure you see a message like "Take from Stockpile #1".
* The take conditions must correspond with the contents of the stockpile.
* The track stop may be set to dump. A track stop set to dump cannot be filled. You must either set the stop to a time-based departure or deconstruct the track stop and rebuild it without dumping. (Alternatively, with [[DFHack]] you can modify "Dump on arrival" to "No" using the {{key|q}} menu without rebuilding the stop.)
* Make sure the minecart itself has not been designated to be dumped (such as when using mass-dump).

'''Symptom:''' Dwarves fill the minecart properly, but will not move it thereafter.

'''Possible Causes:'''
* The minecart may contain items which are not included in its current stop's desired items. Check inside the minecart using the {{key|k}} and {{key|z}} keys and ensure that all items in the cart are desired items.
* The minecart may contain desired items in bins. Minecarts seem to have problems realizing that they are in fact full of desired items if some of those items are in bins, even if bins are also among the desired items for that stop. '''This cannot be solved by adding the appropriate bins to the stop's desired items.''' Either disallow bins in stockpiles you intend to load minecarts from, or set the departure conditions to rely only on percentage of total load rather than percentage of desired items using the advanced conditions menu ({{key|C}} key).

'''Symptom:''' Dwarves repeatedly attempt to load the minecart, but no items are ever loaded into it.

'''Possible Causes:'''
* This can be caused by using a Track Stop with autodumping enabled at a loading site. Every time a dwarf places an item into a cart resting on such a track stop, the item will be immediately dumped, causing unlimited, useless cart loading jobs. Autodumping Track Stops should never be used at a loading site.

'''Symptom:''' A dwarf picks up the minecart and carries it to its destination.
* See [[#Quirks|Quirks]]

=== Danger ===
Minecarts are not without <strike>danger</strike> [[fun]]. Although designating a track automatically sets the [[traffic]] designation to low, dwarves ''may'' still walk on them, and [[creature]]s ignore traffic designations altogether. If an unlucky dwarf or creature fails to [[dodger|dodge]] a minecart, they can be injured. Most of this danger can be avoided by setting the minecart {{k|h}}auling commands to guide instead of push or ride (dwarves guiding minecarts will ignore traffic restrictions), as well as by [[pasture|pasturing]] domestic animals and preventing the access of other creatures to the tracks. Note that removing the track doesn't reset that tile back to normal traffic priority, so you may wish to manually clean up traffic designation afterward. Also note that bridges that are used as tracks don't have their traffic priority changed automatically (since they're just normal bridges), which could cause dwarves to pathfind normally through dangerous minecart entrances in your fort's walls if you're not careful.

The only <s>fool</s>''dwarf''-proof method is to make the tracks inaccessible. There are several ways to create a track which works for minecarts but doesn't allow creature-traversal; the simplest is perhaps building a [[statue]] on the tracks. Other options include adding single-tile holes (minecarts moving at reasonable speed will jump the gap), vertical drops, minecart-triggered doors, small pools of liquid (4/7 water or 2/7 magma), and hostile creatures overlooking the tracks. For safety, both ends of the track should be isolated, making the dangerous center sections completely inaccessible (though maintenance access can be provided by a locked door).

Danger does not always involve living victims: careless route designation can also result in minecarts careening off tracks or colliding with each other. If this occurs, the [[item]]s may be scattered; this can cause even more hauling jobs than the minecart aimed to eliminate. Even <s>better</s> worse, scattered items, especially [[weapon]]s, can injure passing [[dwarf|dwarves]] or other [[creature]]s; in the words of Toady One the Great, "Accidental grapeshotting of the dining room should be possible now."

Of course, the danger of using minecarts means they can also be [[Trap_design#Minecarts|used as weapons]] by imaginative players.

== Advanced usage and automation ==
Minecart-specific effects are implemented via track stops, rollers and [[pressure plate]]s with "track" condition set. Since all three are considered [[building]]s, they can't be built on the same square (however convenient track stop + pressure plate would be) nor a simple ramp, and are removed by {{k|q}} {{k|x}}.

=== More on Track stop ===
Track stops are constructions that allow further automation of minecart systems via adjustable features such as braking by friction and automatic dumping of contents. They can be built from logs, bars and blocks through {{K|b}} {{K|C}} {{K|S}}; friction amount, dumping toggle and dumping direction must be set '''before''' construction, and these settings can be neither changed nor seen thereafter; however, track stops can be linked to [[pressure plate]]s or [[lever]]s to toggle friction and dumping On or Off (trigger state is inverted: switch On = track stop Off).

If a [[stockpile]] is placed on the tile that a track stop is set to dump to, it can act as a [[Exploit#Quantum_stockpiles|quantum stockpile]] and any items dumped from a minecart that match the storage settings of the stockpile will remain there and accumulate. Normally trackstops are built on top of existing track to operate on moving minecarts, but they can also be used without tracks to create [[Exploit#The_Minecart_Stop|automatic quantum stockpiles]] (see also [[#Step-by-step_tutorial|step-by-step tutorial]]). It is not always desirable to collect ALL of certain items into one quantum stockpile, such as when distributing a material to multiple separate industries. You can link your quantum stockpile to various other stockpiles, ensuring that your dwarves will keep them supplied as necessary. Because quantum stockpiles never fill up like regular stockpiles, it may be a good idea to add a switch to turn them off.

Items dumped from a minecart at a track stop (or dumped by any other means) into open space fall through z-levels until they land on a solid surface. Items falling onto a designated [[stockpile]] will automatically be considered part of that stockpile, even if the stockpile is set to disallow those items (they will, however, be automatically moved to a more appropriate stockpile, if available). Items falling on top of a minecart will '''not''' fall "inside" the minecart. Use with caution; dwarves have fragile skulls.{{bug|5945}}

=== Automated propulsion ===
==== Roller ====
{{Main|Roller}}

A '''roller''' is a [[power]]ed [[machine component]] for the automated propulsion of minecarts. They are built over the top of existing tracks with {{K|b|M|r}}, requiring a [[mechanic]], ''(length/4)+1'' [[mechanism]]s and a [[rope]]. Rollers may also be placed directly on ramps to help pull carts up Z levels. Rollers are very useful to maintain a cart's momentum along long routes, to get them to climb Z-levels without dwarfpower involved, and to get them to reach speeds unattainable by guiding dwarves. These devices are variable-length (1-10), variable-direction and variable-speed ([[Minecart#Numbers_behind_the_scene|see below]]), all traits that can be set at construction time; a roller uses two units of power per tile it is long.

Single-tile rollers transfer power in all four cardinal directions, while other rollers generally only transfer power perpendicular to their activity direction. Longer rollers can also transfer power along their activity direction if built in the correct order, although this can be hard to accomplish and is easily broken. Rollers cannot be powered from above.

Rollers have great acceleration and capped speed. Carts going faster than the roller are unaffected. If a cart moves across an active roller in the direction the roller works and moves slower than the roller's specified speed, the cart will be set to the roller's speed. A cart going against a roller's movement direction will be sent back the way it came (once again at the roller's speed), unless it was moving extremely fast: speed increment of 100000 allows to reverse carts from the full "highest" (50000) speed roller to full "highest" speed back, but ramps can accelerate a cart beyond this. {{cite forum|144328/5702453}}
A cart crossing over a roller perpendicular to its current movement direction will gain the roller's amount of speed in the perpendicular direction without directly changing its forward motion. Without an adjacent wall to constrict its movement, this will typically send a cart off the rails on a diagonal path, completely unable to follow any tracks until it collides with a wall or is otherwise brought to rest. However, if the roller is placed over a track turn and pushes ''from'' the direction of that turn's track, the turn affects carts ''after'' the roller, so they will be forced into the turn rather than derailed in a diagonal direction. {{cite forum|144328/5702453}}

{{diagram|spaces=yes|\
tracks: full:
║ ║
═╗═ ═╢═
║ ║

╢ : roller pushing from W to E
}}
If the roller is powered, carts from ''all'' directions (unless too fast) exit S, because speed imparted by the roller forces carts toward E and ''then'' into the turn.
If not powered, carts from W and N exit S, carts from E and S exit W. Carts above derail speed will ignore the turn, of course.

{{diagram|spaces=yes|\
║ ║
═╗═ ═╟═
║ ║

╟ : Roller pushing from E to W
}}
Carts from the E or W: exit W.
Carts from N: derailed diagonally, exit SW.
Carts from S: derailed diagonally, exit NW.

Rollers affects carts on a track - if placed on a floor or ramp without any tracks, they are ignored. Depowered rollers are also ignored, friction is determined by the tiles underneath.

Because of their one-way nature, rollers are unsuitable for most two-way minecart tracks (unless you set gears toggling roller A->B off while toggling A<-B rollers on). However, a minecart set to be ''guided'' is not affected by rollers at all{{cite forum|109460/3286235}} — this allows a one-way track to be used in both directions. In addition, unpowered rollers do not affect minecarts.

Care must be taken in [[glacier]]s and other extremely cold [[biome]]s, since rollers (and the machinery used to power them) will not operate when constructed on natural [[ice]] floors.

==== Impulse ramps ====
Carts can be given momentum without rollers or changing z-level through a phenomenon called "impulse ramps". A track ramp which is connected both to a wall and to a floor will ''always'' accelerate a cart towards the connected floor tile, no matter where the cart enters the tile from. This means carts can be accelerated as though dropping z-levels, even if the cart doesn't actually change z-level at all. If a track ramp faces three directions such as ╩, then two of those directions need to be facing walls for the cart to be accelerated towards the remaining direction.

Example of straight impulse acceleration:

{{diagram|spaces=yes|\
▒▒▒▒▒▒▒▒▒▒ ▒▒▒▒▒▒▒▒▒▒
═▲▲▲▲▲▲▲▲▲▲═ ═╚╚╚╚╚╚╚╚╚╚═
▒ : Wall
═ : Normal track
▲/╚ : N/E Track/Ramp
}}

If a cart enters from the left, it will speed up on every track/ramp and exit to the right going very very fast - more than one tile every step. If it enters from the right then it will bounce back impulsed by the ramp if it's going slow enough.

As another oddity, carts coming from ramps will in some cases "teleport" through most of the next tile. This can be used to send carts up levels with minimal loss of speed. You can just make an upward spiral alternating impulse ramps and regular upward ramps. It takes no power, is quick and cheap to build, requiring only channeling and track carving, and the cart goes up fast, but not so fast that it launches its contents.

Example of an impulse elevator:

{{diagram|spaces=yes|\
z +0 z +1 z +2 z +3
░░░░░ ░░░░░ ░░░░░ ░░░░░
░╔░░░ ░▼╚╗░ ░░▼▼░ ░░░░░
░╝░░░ ░▼░░░ ░░░╔░ ░░░▼░
░▼▼░░ ░░░░░ ░░░╝░ ░╚╗▼░
░░░░░ ░░░░░ ░░░░░ ░░░░░

░ : Wall
╔,╚,╗,╝ : Track/Ramp
▼ : Down Ramp (empty space)
}}

A sort of opposite effect to impulse ramps also exists: ramps lacking the proper "up" and "down" connections are treated as flat track, even if they actually go up or down z-levels. This allows building "anti-impulse" slopes consisting entirely of ramps only connected up, which a minecart can travel up forty levels and more, needing no more than a single push.

=== Controlling traffic ===

==== Switching ====

As constructions or tile features, [[door]]s and other furniture can be built on tracks. A [[door]] or [[floodgate]] can be turned on or off by a [[lever]], effectively controlling the flow of automated minecarts. This may be <s>dangerous</s> [[fun]], however.
{{diagram|spaces=yes|\
->
A ════┤≡════ B
┤ : roller pushing to East
≡ : door
}}
The roller pushes the cart east, but until the "departure condition" is fulfilled, the door remains closed and blocks the path.

[[Bridge]]s can also act as tracks, but only if they're lowered or not retracted. This property can enable levers to turn tracks on and off. However, care should be taken to ensure that such bridges are never operated while a cart is on top of them, as the cart will be flung off the track. It's worth noting that it's often faster, and cheaper, to construct large bridges than long sections of constructed track.

A powered track switch can be constructed by building an "inverted" corner as illustrated below.
{{diagram|spaces=yes|\
B B
║ -> ║
║ ║
════╚═══ ════├════
A C A C
├ : roller pushing to West.
}}

If the cart is pushed East from the stop at 'A' while the roller is activated, it will arrive at 'B'. If the roller is not running, it will arrive at 'C'. The switch works by the roller first reversing the incoming cart's movement and the cart ''then'' following the track corner.

This switch is very reliable, reacts instantly to on/off signals, and carts of any speed can be switched by this design, although very fast carts will require rollers that are several tiles long, up to three. The requirement for power can be inconvenient or impractical. Non-powered solutions may use controlled derailment, or a connecting bridge.
{{diagram|spaces=yes|\
B ╥
║
║
╞════╝ ════╡
A D C
}}
Here the track between A and C is not continuous. The only continuous track is A->B, with a corner (not a T section). Fast moving carts will tend to derail at D and rejoin the track to C. Placing a door at D will prevent the derailment, so the cart continues to B. The door is operated by mechanisms elsewhere (typically, a lever, but some fun can be had with pressure plates).

Since it depends on derailing, this switch requires a very fast cart, faster than what can be achieved with rollers alone. To gain sufficient speed, a cart must be accelerated further, usually by descending several levels or through impulse ramps. The high speed makes the cart much more dangerous and harder to control.

If carts are moving too slowly to derail at the corner, a retractable bridge may be used as a connector between A and C.
{{diagram|spaces=yes|\
B╥
║
║
A╞════bbb════╡C
}}
The bridge must overlap the corner. Bridges behave like a track crossing, allowing carts to pass in a straight line. When retracted, the corner reappears, so the carts will continue to B. Bridges take 100 steps to react to a signal, necessitating rather long "lead times" when switching tracks via bridge.

As mentioned above, special care must be taken to make sure the bridge doesn't change state while the cart is passing over it. Retracting bridges will throw the cart, causing it to stop dead. Raising bridges can even crush the cart.

==== Controlling Speed ====


Minecarts can reach extremely high speeds, especially when descending multiple Z-levels. A minecart will derail at a track corner if its speed exceeds 0.5 t/st (tiles per step), '''unless''' the route in the direction of travel is blocked:

Will derail at > 0.5 t/st:

{{diagram|spaces=yes|\
in ══╗ -> derailing
║
out
}}

Will not derail at > 0.5 t/st:
{{diagram|spaces=yes|\
in ══╗O
║
out

O : wall/column.
}}

This behavior can be used to build a "speed limiter", that will ensure that when a minecart exits it is traveling below derail speed:
{{diagram|spaces=yes|\
░░░░ ░░░░░ ░░░░░
in ═╔═╗░ ░╔S╗░ ░╔S╗░
out ═╬═╝░ out ═╗═╝░ out ═╗═╝░
░╚S╝░ ░╚═╝═ in ░╚S╝░
░░░░░ ░░░░ ║░░░
in
░ : wall
S : Track Stop (High Friction or lower)
}}
If the minecart is traveling below derailment speed, it will not be affected; if above, will be slowed down and checked again. Granted, you could do the same just with track turns, but it may take a lot of turns and time.

Since all the derailings, bounces and ramps can impart a sideway component of speed small enough to start visible drift many tiles away (say, [[Fun|in the middle of a bridge]]), track turns have one more use: forcing the carts to move strictly along the grid directions. Carts passing a turn below derailing speed convert one component of velocity into another, thus eliminating the drift.

=== Loading liquids ===
[[Water]] and [[magma]] can also be loaded into minecarts by submerging them to a depth of at least 6/7 while standing still or moving at speeds of at most 10000. Loading fluids onto minecarts can be difficult because the added friction provided by fluids can stop a cart in a submerged tile. Curiously, filling a minecart with magma does not injure a dwarf ''riding'' it. A minecart will hold enough fluid to increase the depth of a single tile by 2. This amount is listed as 833 units, which weigh 459Γ (water) or 999Γ (magma). An iron or steel cart filled with magma weighs 1313Γ, while an adamantine cart filled with magma weighs 1007Γ. Since you need a minecart above the liquid's level, possible arrangements may include pressure-activated sluices, rollers (with magma-safe chains for magma), pouring from above to "submerge" it briefly on the same level and drain excess away (dig deeper and leave a vaporizer, though if you could have power for rollers, may as well use a pump) and exploits with ramps (not necessarily impulse ramps, "same height" passing dip does it).
The liquids can be dumped by a constructed track stop.

== Quirks ==
This little quirk concerns dwarf-managed minecarts. If a track which was previously open becomes blocked (ex. flipping a switch connected to a floodgate you've built on the track to raise it) and the conditions for departure are met, instead of refusing to ride/guide the minecart or ride/guide it until it reaches the obstacle, the dwarf will pick up the minecart off the tracks and haul it to its scheduled destination on foot. If the distance is long enough and the weight of the cart heavy enough (due to being filled with heavy items such as stones), the dwarf may drop the cart because of fatigue/hunger/thirst before reaching the destination. This will cancel that vehicle setting job and make another dwarf come by and attempt to haul the cart to the nearest appropriate stockpile where another dwarf will pick up the cart and attempt to haul it to its initial stop. If the stockpile is far enough from initial stop, this second dwarf who is attempting to place the minecart on its tracks may also drop the minecart out of fatigue/hunger/thirst creating a loop that will go on until a dwarf with enough endurance manages to place the minecart where it belongs.

In fact, it seems dwarves are more than happy to attempt to carry a minecart from one stop to another even if just waiting until the track is open again would be the more sane option.

Dwarves will also carry a minecart to its next stop if the direction specified is incorrect (or invalid). This can often occur when using the default departure settings and forgetting to set the direction of each condition.

Dwarves can admire buildings while riding mine carts. Dwarves will not fall asleep during a ride (at least not from being drowsy). If riding on a continuous powered track loop, the dwarf will die of dehydration/starvation as they can not jump off to get sustenance{{cite forum|109460/3377228}}. Dwarves riding in submerged minecarts will gain experience in [[swimming]].{{cite forum|129889}}

Tracks block wagon access to trade depots, unless they're on a ramp. [[Bridge]]s can also be used, as they function as tracks but do not block wagons.

== Physics ==


Minecart physics depend greatly on the departure mode set in the route stop conditions.

When set to "Push" or "Ride", minecarts will move according to the regular laws of momentum, gaining speed when going downhill, losing it slowly due to friction when on a flat plane, and more quickly when going uphill. In these modes, minecarts will move in a straight line until they either are brought to a stop by friction or an obstacle, or until they encounter a turn. A minecart will roll straight past "blocked" ends of T-junctions or track ends, they have no power to restrict a cart's movement. The cart's behavior is largely independent of the weight of its contents (including fluids and dwarves): heavily loaded carts gain more momentum when accelerating, but this only plays a role in collisions: a heavy cart gains just as much speed and is as easy to stop as a light one. In either case, dwarves can not push nor ride an unpowered cart up a ramp, bouncing back the direction it came. At best, this is a waste of time; at worst, it will give your cart-pushing dwarf a [[fun|fun surprise]]. To solve this, the player can either use Rollers (see below) or set the cart to be Guided.

The difference between "Push" and "Ride" is whether the dwarf will go along with the cart or not.
{{DFtext|Push}}: the dwarf will give the cart an initial push, not enough to go up a ramp, but enough to go some way along flat track, and the dwarf will remain at the first stop, ready for a new job.
{{DFtext|Ride}}: the dwarf will give the cart the same initial push and then hop aboard the cart riding with it to the next stop.
{{DFtext|Guide}}: minecarts seem to ignore all laws of physics. That is:
*Ignore the weight of any and all items inside. Therefore:
**Move at the speed of the dwarf that is guiding them. It is thus recommended to pick the most [[attribute#Agility|agile]] of your dwarves for cart-guiding tasks.
*Ignore working rollers.
*Will ''not'' collide with other guided carts even when a full frontal collision would be expected.
*Will go up ramps like nobody's business.
This is therefore the recommended method of transport for simple non-powered rail systems, despite it diverting a dwarf from other, potentially more important tasks.

Some samples with behavior:
{{diagram|spaces=yes|\
A <-> B A <-> C A <-> B
B B B
║ ║ ║
A══╝ A══╩══C A══╬╗
You can only go A->B ╚╝
Works when the cart Works
is in Guide mode.
}}
In the second example above, a cart "pushed" from B will go over the junction and roll off into the unknown south.

=== Track Direction Irrelevance ===
Carts that are traveling independently, (that is, not guided,) only care that tracks ''are'' on the tile, not which direction the tracks actually move. Tracks respect only curves (with two exits) and ramps.

This means, for example, that the following tracks, when a (non-guided) cart travels from West-to-East, are functionally identical in effect:

A════════════B A╬║╚╔╣╩╦╠╥╨╞╡B

This is because so far as the cart is concerned, only ramps and curves with two exits where the exit in the path they are traveling matters.

Carts only check for curves when they are halfway through a tile. When they get there, they look to see if their path has no exit. (That is, if it is traveling East, it checks if there is an East exit.) If there is, it ignores all other track directions, and keeps traveling. If there is not, it checks to see if there are only two exits to the track, and if one of those directions was the direction it "came from". (That is, if traveling from the East, it checks if there is a valid exit to the West, and if so, if there is either a North exit or a South exit.) If there is not, it ignores the track anyway, and keeps on traveling as though it were still on track. If there is, it will subtract 1000 from the velocity of the cart, and redirect all forward velocity to the direction of the curve. This change in the direction of velocity ''overwrites'' any "diagonal" velocity, which can prevent diagonal velocity derailments, but any perpendicular velocity is not preserved, and is instead discarded.

=== Skipping ===
If a minecart is moving fast enough, it can skip over [[water]] or [[magma]], making splashes of [[mist]] (or [[magma mist]]) as it attempts to move on them horizontally. This horizontal movement is independent of the minecart and its content's [[weight]].

=== Track Jumping ===
If a minecart encounters the end of the track or a T junction with no "exit" in its movement direction, it will simply leave the track and continue on its course in a straight line until it encounters an obstacle, slows to a stop, or encounters another (properly aligned) Track even if the tile at which it joins the new track instantly sends it around a corner.

Tracks that are travelling at high enough velocity will also start "jumping" the track if it hits an un-tracked tile (flying over and ignoring any tracks) until it is ready to land. Carts that land upon tracked tiles re-rail themselves, and clever designers use this feature to jump over curved track sections in one direction or another. (Retracting bridges over untracked tiles can cause jumps or not cause jumps depending upon the status of the bridge.) Minecart speed must be carefully regulated to ensure reliability of jump length.

Carts that approach a downward slope at a high enough velocity will also make a jump, but will not do so if the Checkpoint Effect (below) is exploited through an impulse ramp before the actual downhill as the impulse ramp "tricks" the cart into thinking it has already started going downhill.

=== Invalid Ramps ===
Ramps are functionally defined for cart purposes as being a tile which exerts an acceleration force upon its "downward slope". This downward slope requires a cart to have one ''and exactly one'' carved exit to the tile that is the "bottom" of the ramp. Ramps push carts in this "downward" direction (possibly leading to diagonal movement, below), and the deceleration of an "uphill" ramp is actually just the acceleration being applied against the direction of a cart's movement.

This is where players can find an exploit in the behavior of ramps - if there are ''two'' "downhill" exits to a ramp (such as a "T junction" on a ramp where only one exit faces a wall), then the ramp provides no acceleration ''or'' deceleration, allowing carts to travel up ramps without any loss of momentum except for the standard "flat track" deceleration, because as far as the cart is concerned, the track ''is'' flat.

Similar effects can be achieved when there are ''no'' "downhill" exits to a ramp. This may be the case if you have, for example, an East-West track with a one-tile channel with a ramp in it. The cart will travel through the "dip" with no change in velocity. It can also be the case if you abuse the Track Direction Irrelevance, above, and set only exits ''up'' the ramp, and none leading ''down'' the ramp. For example, if a cart is traveling from West to East up a slope, only carving East exits on each tile of ramp will make the cart travel up the ramp, and then recognize the tile it is on as being a "flat" tile, thus ignoring any deceleration from traveling uphill.

=== Corner Ramp Derail ===

Corners on upward ramps can cause diagonal movement, forcing a derail even if the cart has a wall next to it, which will force a stop when it touches a wall that forces dwarves to manually reset the cart.

This is caused by the fact that a cart, after turning the bend in the track halfway through the length of the tile, will still "accelerate down", which is now perpendicular to the movement of the cart, causing acceleration to occur in two directions. (Down corner ramps do not have this problem, as when they pass the halfway point, all perpendicular motion is added to forward motion, and after that curve, all downward acceleration is in the forward direction.)

There are two fixes to this problem. One is to simply not put corners on up ramps. The other is to take advantage of the Checkpoint Effect, below, by making a ramp (possibly including an impulse ramp) one tile in front of the ramp to make it skip through most of the tile before sideways momentum can be built.

=== Checkpoint Effect ===
The checkpoint effect, [http://www.bay12forums.com/smf/index.php?topic=144328.0 explained in depth by Larix], is an odd and highly exploitable feature of ramps where minecarts "teleport" through the next tile of track, ignoring nearly all minecart physics (except that they stop at all walls or other obstacles and not only respect curves, but will take them even when they would otherwise derail) and passing through that tile in just a single tick, and into the next tile at the halfway point.

This effect occurs when a cart leaves a downward ramp for any other direction of tile. This allows, for example, two valid straight ramps directly next to one another with a cart dropped onto one or the other with no momentum to have the cart pick up acceleration going "down" the ramp as normal, but then flying up through the "up" ramp it travels into with no loss of momentum, as though it had come from an impulse ramp. If the two ramps had at least one space of distance between them, and then a cart were dropped in, the cart would instead "rock" back and forth between the two ramps.

This seems to be because ramps have a slightly longer length than regular tiles - 144,000, rather than 100,000 distance. When this "snaps back" after a ramp, it seems to project the cart suddenly further along the track, making it jump a tile ahead even when otherwise moving at relatively low speeds.

This effect would be a "[[bug]]" if it weren't probably deliberately coded, and an "[[exploit]]" if it weren't impossible not to feel its effects. Nevertheless, many designs exploit the checkpoint effect to allow "perpetual motion devices" where a cart stuck between two ramps can climb a ramp with no loss in momentum, creating unpowered perpetual motion devices. This also allows for ramp "elevators" to be constructed even without impulse ramps (although impulse ramps make it more compact, still).

Another useful thing to note about this exploit is that carts traveling at no less than 72,000 or so speed (enough to travel half a ramp tile in a single tick) can travel through every tile in just one tick at no change in velocity as long as the tiles alternate between impulse ramp or actual down ramp and any other tile type. The cart checkpoints through the non-down-ramp tiles, and can pass through the (impulse) down ramp tiles in a single tick, before they can actually start gaining momentum.

=== Falling ===
When falling, a minecart appears to cause no damage upon collision, possibly to allow cart "stacking" across Z-levels.{{cite devlog|2012|04|06}} A dwarf riding in a minecart that is dropped multiple z-levels suffers normal fall damage. Minecarts can fall through up/down stairs.
The cart falling (from a hatch, thus with no horizontal speed) onto a track ramp is accelerated as if starting from the middle of the ramp - i.e. to the same speed, no matter how many Z-levels it was dropped, vertical velocity is negated. {{cite forum|144328/5701211}}

=== Stacking ===
If a minecart lands on top of another minecart, they may form a stack, with the upper cart on the z-level above the lower. Subsequent carts do not form a stack, but rather quantum stockpile in the same space. This behaviour is useful for [[megaprojects]] and [[trap design]] with minecarts as the weaponry. Moderation should still be exercised: carts take longer to fall into a "stacking" tile already occupied by other carts and will spend that time "hanging" in the air above the stack. This can lead to following carts striking them, which can cause all kinds of malfunctions. The extra time is two game steps for every cart already in the stack, which doesn't hurt stacks of ten carts very much but makes stacks of 100+ rather impractical.

These minecarts on the upper level generally need to be struck with another minecart to move out, or have their support removed. The latter option is safest done by shooting it away with another minecart, manual removal of a stack-supporting cart typically causes the next cart from the stack to [[fun|fall on top]] of the hauler.

=== Perfectly Elastic Collisions ===
Minecart collisions are perfectly elastic, meaning that not only do minecarts not take damage, but that two carts that are rolling which have frontal collisions of near-similar speed, and where one cart is no more than twice the mass of the other cart, will result in a billiard-ball-like effect of the lighter cart bouncing off the heavier cart with a proportional speed increase dependent upon the relative momentum behind the heavier cart.

Using this trick with carts already at the 270,000 maximum speed from ramps can result in "supersonic" carts traveling at speeds in the millions (travelling a dozen tiles per tick), but where they are suddenly subject to 10,000 units of "terminal velocity" friction per tick. [http://www.bay12forums.com/smf/index.php?topic=137557.0 Thread with SCIENCE here].

While hypothetically capable of launching a minecart into orbit when used in conjunction with a ramp, no cargo can be contained in the launched cart, as the collisions will force ejections of the cargo. Your "unwilling volunteer" [[goblin]] space pioneers will simply become paste underneath the wheels of an extreme high-speed cart.

=== Numbers behind the scene ===

According to early research by '''expwnent'''{{cite forum|112831/3536975}}:

The minecart has a variable for speed. Speed is measured in tiles/100000 ticks, so a speed of one hundred thousand means one tile per tick. By going down a large number of ramps, a maximum speed of 270,000 can be reached, which presents the limit for most practical applications. Short bursts of (much) higher speeds are possible through carefully planned collisions of high-speed carts {{cite forum|137557/5145499}}.

Every tick the cart accumulates distance units, as well as slows down depending on current tile (speed is reduced by "friction" of the tile). The cart will move to the next tile the tick before accumulating 100000 distance units, (or several tiles in case of great speed), then the leftover distance units are added to the default 100000 distance u. of the next tile. Since most deceleration and acceleration is applied per step, with the notable exception of corners, a cart going at twice the speed of another one can cover about four times the distance in a straight line, but only twice the distance along a winding track with very many corners.

A push will teleport a cart to the beginning of the next tile (NOT the middle!) in one tick with 19990 speed (10 speed is lost due to track friction), while a roller will give a cart the roller's set speed, and it will start to accumulate regular track friction past the middle of the roller tile. Some track features will affect a minecart when it is past the middle of the previous tile: entering a ramp or a hole/drop will happen when the cart has left the middle of the previous tile, and the ramp will gain additional distance unit depending on the leftover units from the previous tile. When a cart leaves a ramp it will emerge after one tick in the middle of the next regular tile, so its entry coordinate is "50000-speed+friction". Rollers also affect the speed of minecart from the middle of the previous tile.

Friction of tiles:
{| class="wikitable"
|-
! Tile
! Friction
! Comment
|-
| Tracks
| 10
|-
| Ground/Floor
| 200
|-
| Unusable ramp
| 10
|-
| Upwards ramp
| 4910 (10+4900)
|-
| Downwards ramp
| -4890 (10-4900)
|-
| Roller
| ±100000 (but capped by the set speed)
|-
| Corner track
| 10
| Speed reduced by 1000 upon leaving the corner tile
|-
| Track stop (highest)
| 50000
|-
| Track stop (high)
| 10000
|-
| Track stop (medium)
| 500
|-
| Track stop (low)
| 50
|-
| Track stop (lowest)
| 10
|-
| Water 1-6
| Additional (WaterLevel - 1) * 100
| rowspan="2" | [[#Skipping|See Skipping]]
|-
| Magma 1-6
| Additional (WaterLevel - 1) * 500
|-
| Empty space
| 0
|}

Water of depth 7/7 provides a friction of about 10000 per step, as does maximum-depth magma. This higher friction may not apply to very slow-moving carts.

Impulse sources:
{| class="wikitable"
|-
! Feature
! Speed
|-
| Push
| 20000
|-
| Roller lowest
| 10000
|-
| Roller low
| 20000
|-
| Roller medium
| 30000
|-
| Roller high
| 40000
|-
| Roller Highest
| 50000
|-
|}

== Non-standard uses ==
Minecarts include some interesting characteristics that have motivated uses beyond hauling. They can be useful for creating fully-automated [[exploit|quantum stockpiles]] and [[garbage disposal]]s. Storing perishable goods (meat, meals, etc.) inside a minecart appears to guard against rot and vermin.
Minecarts can be [[Trap_design#Minecarts|used as weapons]], or as (hopefully non-fatal) triggers to restart stalled [[healthcare]]. They can also be used to time/control game events, either using a basic [[repeater]] or much more advanced [[minecart logic]].
Minecarts trigger [[pressure plate]]s, which means a trap can be designed to trigger when a thief attempts to steal a minecart.
A pressure plate can be used as automatic and more precise custom "launch when full enough" system - as long as weight of your minecarts stays the same. You cannot build a hatch or roller on the same tile, so launch by bumping with another cart. {{cite forum|15096/4580050}}
Dwarves riding minecarts can attack enemies within reach (which goes back to dev log). This applies to shooting, and they actually can hit targets while riding by.{{cite forum|109460/5266119}} Whether a minecart protects the rider and how it interacts with dodging is not known yet. Minecart riders can also [[Swimming#Minecart_training|train swimming]] and [[Megaprojects#Surveillance_Track|detect ambushers]].

== Adventure mode ==
In addition to being used for hauling, minecarts can also be ridden in [[adventure mode]]. (Adapted from forum thread {{cite forum|122903/4258212}})

# If the minecart is in your inventory, drop it. If it is already on the ground, proceed to step 2.
# Press {{k|u}} when you are 1 tile away from the minecart (or standing on the same tile as the minecart).
# You will be presented with the following options:
[[File:minecart adventure mode menu.png|left]]
{{clear}}
* If you {{DFtext|Push}} the minecart, it will move a few tiles in the direction you chose. Physics comes into play here, so it will gain/lose speed depending on the usual factors.
* If you {{DFtext|Ride}} the minecart, you will hop into the minecart, even if you were a tile away, and it will move in the chosen direction with you in it. It will gain/lose speed depending on the usual factors. Whilst the minecart is in motion, you should press {{k|.}} to skip your turn; if you attempt to move whilst the minecart is still in motion, the laws of physics come into play, and you will take [[wound|damage]]. Alternatively, you can push the minecart whilst it's still in motion (although it's unclear how one can bend [[physics]] so as to push a moving minecart whilst inside the minecart). If you push it in the same direction you are already travelling in, you will greatly increase the minecart's velocity. You can also push it in different directions, and this will cause it to gradually change direction-the amount of pushes this requires depends on the minecart's velocity. Once the minecart has stopped moving, you may move out of it safely, or you may want to give it another push. Note that if you push a minecart right after having ridden it (still on the same tile as the minecart), it will act as though you chose to ''ride'' it.

If you want to test this out without creating an adventurer, the [[object testing arena]] allows you to spawn minecarts ({{k|k}}-{{k|c}}-{{k|n}})

== Forging and Melting ==
* Metal minecarts cost '''two''' [[metal]] bars to forge, or '''six''' [[adamantine]] wafers.
* When a non-adamantine metal minecart is melted down, it will return '''1.8''' metal bars, for an '''efficiency of 90%'''.
* When an adamantine minecart is melted down, it will produce '''1.8''' wafers, for an '''efficiency of 30%'''.

== See also ==
* [http://www.bay12forums.com/smf/index.php?topic=109460.0 The "How Does Minecart" Thread] by '''Girlinhat''' et al.
* [http://www.bay12forums.com/smf/index.php?topic=112831.0 SCIENCE: Quantifying minecart physics] by '''Snaake''' et al.
* [http://www.bay12forums.com/smf/index.php?topic=129676.0 How to build a Multi-cart Ore to Magma Minecart Project without needing power] by '''WanderingKid'''.
* [http://www.bay12forums.com/smf/index.php?topic=144328.0 My very own Minecart Education Thread. Ten Lessons, now complete.] by '''Larix'''.

== Bugs ==
*A dwarf will drop her [[child|baby]], if she has one, when boarding a minecart set to be ridden.
*Dwarves have no concept of traffic safety and will walk into busy minecart lines to retrieve objects, often with deadly consequences. This is especially problematic in [[Swimming#Minecart_training|clever applications]] depending on dwarves riding the carts very frequently, because they have a bad habit of dumping their worn clothes on the tracks after a minecart ride. Adding an automatically-operated [[hatch cover]] at the end of such a ride can help prevent [[unfortunate accident]]s.
*Dwarves cannot guide a minecart through an unlocked door unless another dwarf opens the door.{{bug|6056}}
*It is possible for a creature and minecart moving towards each other to pass without collision if they exchange tiles in the same tick.
*After a minecart ride, a dwarf will sometimes haul the minecart to a storage stockpile, leaving another dwarf to haul the vehicle back to the route.
*Minecarts falling onto a floor injure creatures in the tile below the floor.{{bug|6068}}
*A minecart's initial velocity is not affected by weight, when pushed or launched from rollers.{{bug|6296}}
*Removing a stop that has a vehicle waiting on it may cause the game to crash.{{bug|5980}}

{{Category|Fortress mode}}
{{Category|Interface}}

[[ru:Minecart]]

Minecart

2015-06-18T01:45:14Z

NW Kohaku: /* Physics */

{{Quality|Masterwork|08:15, 19 May 2015 (UTC)}}
{{av}}
A '''minecart''' is a [[tool]] intended for [[hauling]], introduced in version 0.34.08. It can be made of [[wood]] at a [[carpenter's workshop]] or [[metal]] at a [[metalsmith's forge]] (using the [[Metal crafter|metalcrafting]] labor.) Minecarts store up to five times as many items as [[wheelbarrow]]s and are quite a bit faster than dwarves hauling objects by hand, but have the disadvantages of requiring a dedicated track network, a complex route planning phase, and the possibility of dwarves [[Fun|blundering into the path of carts filled with lead ore]]. Tracks may be carved into stone, or [[Construction|constructed]]; the latter allows above-ground routes, but these are more difficult to set up due to their additional [[building material|material requirements]].

Just like wheelbarrows, minecarts are considered [[item]]s and are stored in a [[furniture]] [[stockpile]]. Despite their five-times-greater capacity, they are only 33% larger than wheelbarrows and are identical in base [[item value|value]] when made from the same [[material]] (the value may differ due to the [[item quality]]). [[thief|Thieves]] or even mischievous animals can steal minecarts, even when they are moving on a track{{cite forum|109460/3289070}}. However, minecarts moving fast enough or being ridden cannot be stolen.

Although most of the utility of minecarts is in [[fortress mode]], an [[adventure mode|adventurer]] can also ride in a minecart. Adventurers can also pick up and relocate minecarts.

The invention of minecarts revolutionized the [[minecart logic|Science of Dwarfputing]] by enabling smaller, faster logic systems to be built.

== Basic Minecart Usage ==
Minecarts can be used to swiftly transport dwarves, [[flow|fluids]], and/or large amounts of items, but before you have a functional minecart there are several preconditions that need to be met. First of all you need an actual minecart, constructed either in a [[carpenter's workshop]] or [[metalsmith's forge]]. For the minecart to be able to move you also need to carve (with {{k|d}} {{k|T}}) or construct (with {{k|b}} {{k|C}} {{k|T}}) a track, which could be as simple as a straight line. Finally you need to construct stops on your track (with {{k|b}} {{k|C}} {{k|S}}) where the minecart will start and stop.

After you have created the stops and assigned a cart to the track, you must create logic routes connecting several stops and designate starting conditions for each stop. This is done with the {{k|h}}auling key. The most basic conditions are how the cart's movement is initiated and in which direction the cart should start moving. Carts can be either be Pushed (a dwarf stands at a stop and gives the cart a single push) or Guided (a dwarf continually pushes the cart forward, guiding it along the track). The [[hauling]] [[labor]] required for pushing and guiding carts is called "Push/Haul Vehicles" and is turned on by default.

To control which items to transport you can add conditions specifying: (1) which kind of items to be loaded, and unloaded, (2) stockpile links to define which stockpile(s) the items should be un/loaded to and from.

===Capacity and weights ===
Minecarts have five times the [[Weight|capacity]] of [[wheelbarrow]]s.

'''Examples of the capacity of one cart'''
{| class="wikitable"
|-
! Item
! Amount
|-
| [[stone]]
| 5
|-
| [[wood|log]]
| 10
|-
| [[block]]/[[bar]]
| 83
|-
| [[Kitchen|prepared meals]]
| 500
|-
| [[Trap_component#Spiked_ball|spiked balls]]
| 500
|-
| [[Weapon#Native_weapons|mace]]
| 625
|-
| [[Weapon#Native_weapons|spears]]
| 1250
|-
| [[cloth]]
| 2500
|}

The weight of the loaded minecart does not affect the initial velocity received from pushing or launching from a roller. However, the load of a minecart ''does'' affect whether a [[pressure plate]] triggers or not, based on the pressure plate's setting.

'''Weights of different carts'''

{| class="wikitable"
|-
! Type of cart
! Empty cart
! Fully loaded (items)
|-
| oaken minecart
| 28Γ
| 378Γ (10 oak logs)
|-
| platinum minecart
| 856Γ
| 10482Γ (83 gold bars)
|}

The weight of a minecart is one twenty-fifth (1/25) the [[density]] of its material in Urists. Because pressure plates can be set to trigger at intervals of 50 Urists, minecarts with weights just under a multiple of 50 are ideal for switching based on whether they're full or empty. The best minecart materials for full/empty switching are as follows:

{| class="wikitable sortable"
|-
! Material !! Minecart weight !! Content weight required to trigger !! Banana roasts required to trigger (for scale)
|-
| [[Bismuth]] (moods only) || 391 || 9 || 15
|-
| [[Brass]] || 342 || 8 || 14
|-
| [[Electrum]] || 596 || 4 || 7
|-
| [[Fine pewter]] || 291 || 9 || 15
|-
| [[Glumprong]] || 48 || 2 || 4
|-
| [[Lay pewter]] || 291 || 9 || 15
|-
| [[Nickel silver]] || 346 || 4 || 7
|-
| [[Tin]] || 291 || 9 || 15
|-
| [[Trifle pewter]] || 291 || 9 || 15
|}

=== Creating tracks ===
Minecart tracks are made up of contiguous track, tracked ramp, or bridge tiles. Track tiles and tracked ramp tiles have a direction or series of directions associated with them. These directions dictate which directions a minecart on a given tile may move from that tile. For example, a Track NE (northeast) tile allows a minecart on it to move either north or east from its present position. Therefore, if you want your minecart to move east along a straight piece of track, then return west using that same track, you would need to use EW tracks so that the cart could travel east initially, then return west over the same track. Excluding designs in which the cart will "jump" tracks via a drop or other ramp, tracks must be valid end to end to work for most looped or straight-track applications. A single east only track tile in your line of east-west tracks will cause any route using the track to fail the moment it tries to go the wrong way over that tile. Minecart tracks can be built in two ways: Engraved/carved or constructed. A given minecart track need not use engraved or constructed elements exclusively, as the two methods can be used interchangeably depending on the needs of a given section of track. The way the tracks are built is slightly different between the two, as explained below.

====Simple tracks====

'''Carved'''

A single-tile wide strip of natural stone can be designated to be [[Engraver|carved]] (with {{K|d}} {{k|T}}), which will create a straight two-way track. The creation of corners, crossings, and T-junctions is as simple as designating another strip of track that overlaps an existent or newly designated track. Engraved tracks are removed by [[smoothing]] the rock they're on, which results in a smooth floor (that can be re-engraved if necessary), or by building a [[floor]] on top and subsequently removing it. Dwarves can carve corner tracks in one pass by designating the track carving twice and canceling unwanted carvings (with {{K|d}} {{K|x}}). Tracks can be engraved in any natural floor tile, rough, smooth and even over engravings, providing an easy method to remove low-quality or undesired floor engravings. Once a track has been engraved, it's important to check the track directions for each tile in the route carefully to make sure no mistakes were made by yourself or the game's track engraving logic.

'''Constructed'''

Tracks can also be built as regular [[construction]]s (through {{K|b}} {{K|C}} {{K|T}}). This method is resource-expensive, since each track tile requires one stone, [[bar]], or [[block]] for construction, and time-consuming, since you can't designate strips longer than 10 tiles at a time. Corners, crossings, T-junctions, and ramps also have to be designated individually. However, it is usually the only way to build tracks above ground or on soil (barring the [[Obsidian farming|creation of obsidian]]). Constructed tracks are designated for removal like any regular construction; be aware that removing track ramps built on top of natural ones will also remove the original ramp, leaving a flat floor.

====Ramps====

'''Carved'''

The carving of natural ramps is a little more confusing: to carve a two-way track on a ramp (natural only, does not work on constructed ramps), you must designate the track '''starting on the ramp and one square beyond''' in the direction you want the track to go. For the side of the ramp square you want to head upward, there '''must''' be either a natural or constructed wall in the square next to it, otherwise the game assumes you are trying to carve it on the same level -- this can result in the track being carved underneath a door or other object. If you have accidentally done this, you can correct it by smoothing the ramp and constructing a single square of wall next to it, then re-carving the ramp correctly. (However, the wall must stay there permanently; removing it will disconnect the track.)

'''Constructed'''

When constructing track ramps, the stated direction should be the same as the connected tracks. For example, a track going up from West to East would require, starting from the West, a Track (EW), a Track/Ramp (EW) and a Wall behind the ramp, underneath the section of track above it. Incorrectly placed ramps result in minecarts ignoring the ramp and crashing into the supporting wall. They will not, however, display as unusable as when the supporting wall is missing.

'''Examples of ramps'''

A simple ramp would look like this:
{{diagram|spaces=yes|\
z +0 z +1
░░░░ ░░░░
═▲o ░▼═
░░░░ ░░░░
o : wall
}}

Carving track corners into ramps is rather unintuitive and complicated. Since engraving tracks always requires two tiles to connect in a straight line as input, you have to give two separate designations for a single job: a track bit from the ramp tile to the "below" direction and another one to the wall of the "upward" direction. If you wanted to change direction on a ramp from east to north:
{{diagram|spaces=yes|\
z +0 z +1
░░░░░ ░░░░░
░░░░░ ══╗░░
=▲░░ ░░▼░░
░░░░░ ░░░░░
}}
you would need to connect the ramp on z +0 both to the west and to the north by issuing two "carve track" commands, one selecting the ramp and the track tile to the west, and another connecting the ramp tile with the wall to the north. An engraver would then carve a NW track corner into the ramp, allowing carts to pass the corner correctly both going up and down. Such track corners are perfectly serviceable for guided carts, but moving down a route of several of them by pushed or ridden cart is problematic - ramps on corners behave very counter-intuitively, resulting in loss of speed when going down and diagonal movement when going up.

Moving to and from ramps (or between ramps "pointing" in different directions0 causes some non-trivial adjustments to speed and even moving along the tiles at a fixed speed ''unrelated to the entry/exit velocity values'', because transitions to/from ramps are processed differently and are not to be "skipped". This affects compact track/ramp combinations (such as e.g. a simple 2x2 ramp spiral) most, and combined with bouncing often makes them work not in the way one could expect. {{cite forum|144328/5705102}}

{{anchor|Tracks}}

=== Hauling route ===
A hauling route is a list of directions describing how and under what conditions a minecart will move. The proper setting up of routes is essential for a working rail system. Routes, stops, departure conditions and stockpile links are managed from the {{k|h}}auling menu.

==== Route ====
A route defines the path a minecart will take along a track, as well as under what conditions it will move or stop moving. A route is made up of stops. Stops are precisely what they sound like, a position on the track at which you want a minecart to stop. A minecart track might use as little as a single stop for a looped track, which will serve as both a starting and stopping point for the cart, or it could contain many stops, perhaps to load supplies or wait for a bridge to be manually lowered, before reaching its destination or returning to its starting point. It is important to note that you only need to place stops on a route where you actually want the cart to stop and wait for some action to occur. They are not needed to help navigate the cart along the track beyond telling it where on the track to stop.

New routes are created with the {{k|h}}auling key. Existing ones can be removed (without confirmation) with the {{k|x}} key, and also {{k|n}}icknamed. Before operating, the route must have a {{k|v}}ehicle assigned to it (this can be done with either the route or a stop selected). Assigning a full minecart to a route may result in a slow hauling job if the contents are heavy.

==== Stops ====
Stops are the individual waypoints that make up a hauling route. A given stop consists of the location of a tile, as well as conditions describing when, where, and how a cart should be moved after being stopped at that tile. Stops can be created from within the {{k|h}}auling menu, by placing the cursor over a tile and hitting {{k|s}} while highlighting the route (or a stop within) you've already designated. A minecart will begin its route at the first stop created, and continue through each subsequent stop, being guided, pushed, or ridden from each stop to the next depending on the conditions specified. In many basic minecart applications, the cart will end up at the same stop it began at, though this is not always the case. It is important to note that hauling stop order is enforced, even if there is no track. A dwarf will drag the cart overland back to a skipped stop in the route's list if your tracks bypass it somehow.

Once a stop has been placed, it is given a default set of conditions under which to move the minecart if it is stopped there. Each new stop gets the same default conditions regardless of the track it is placed upon (e.g. guide the cart to the north). For this reason new stops might get marked by yellow exclamation marks ({{DFtext|!|#ff0}}) due to invalid directions. One important thing to note is that as you place additional stops, the display will show paths between the stops you have defined. However, this is '''not''' necessarily the actual route the minecart will take once the route is in operation. For example, if a route were defined with two stops at opposite ends of a track with many twists and turns, a line will be drawn directly between those stops to show the order in which they will be visited. These route lines may crisscross all over the tracks, but so long as the track is valid end to end, the cart will follow the track from one stop to the next, even across twists, turns, and z-level changes. Stops, which are the steps that make up a route, should not be confused with Track Stops, described below.

===== Stockpile links =====
By placing the cursor on top of a stockpile and using {{k|s}}, you can create stockpile links while defining a hauling stop. Links can also be redefined by selecting them, placing the cursor over a different stockpile, and pressing {{k|p}}. The cart will then be filled by items present in its various linked stockpiles in preference to other items. Note that bins should be used with caution in stockpiles that are linked to minecarts. Bins cause problems when used with the "Desired Items" list in a stop's conditions. For example, if a minecart is set to accept only granite blocks, and to depart north when it is 100% full of granite blocks, it will not depart if any of those granite blocks are in bins, even if bins are also included in the desired items list. Two solutions to this problem exist as of v0.40.24. First, bins can be disallowed in stockpiles that are linked to stops. Alternatively, bins '''can''' be used in conjunction with minecarts provided that the minecart's departure conditions use only "any items" instead of "desired items." This option can be toggled in the advanced conditions menu for a stop, accessible via the {{key|C|}} key. The cart's contents can still be controlled by specifying what items are allowed in the linked stockpile.

===== Departure condition =====
Departure conditions involve setting conditions in which the minecart will leave on the route. Each condition includes:
# A departure mode (Guide, Ride or Push).
# An initial departure direction (NSEW). Note that this defines the initial direction of movement only. Even if a track includes many turns, as long as the initial movement direction is valid the cart will follow the minecart track thereafter.
# A timer, before which the departure condition cannot be met.
# Conditions on the amount of items in the cart.
Departure conditions are created with the {{k|n}} key. A new departure condition will read: "guide north immediately when empty of desired items". This condition can be changed between basic presets with {{k|c}}. "Advanced" mode ({{k|C}}) allows for more precise control over departure conditions: fine tuning the percentage from 0 to 100 in 25% steps ({{k|f}} and {{k|F}}), switching it being either the maximum or the minimum amount of items for the condition to be met ({{k|m}}), and whether the cart accepts all or only a specific set of items ({{k|l}}). Common to both screens are the departure mode ({{k|p}}, Push, Ride or Guide), {{k|d}}irection, and timer ({{k|t}} and {{k|T}}) options.

To have a cart only carry a specific set of items, the stop can be set to only carry "desired" items, opening the selection screen with the {{k|Enter}} key while having said stop condition selected, and toggling as desired, or it can simply be linked to a stockpile and set to depart once it is full of items from its linked stockpiles, regardless of type.

=== Track Stops ===
A Track Stop, not to be confused with a route stop, is an optional, single-tile construction which serves two purposes. First, it can be used to cancel a cart's momentum in order to slow or stop it as it passes over the Track Stop. This might be necessary if a cart were pushed down a series of ramps to its destination. Second, a Track Stop can cause a cart to automatically dump its contents as it passes over the Track Stop. Track Stops are constructed via {{k|b}} {{k|C}} {{k|S}}, and must be constructed atop an existing piece of track. If a Track Stop has been set to automatically dump a cart's contents, the cart will dump its contents in the direction indicated when it passes over the Track Stop. Depending on the friction settings chosen for the Track Stop, the cart might then stop after dumping, or it might continue on its route to another destination.

Track Stops are not mandatory; in fact, their main use is in automated rail systems. However, even in basic rail systems it can be useful to set a Track Stop to dump items: this saves time that dwarves would otherwise spend in removing items from the cart, time that is better spent driving the cart back to where it's needed. Dumping will occur even with a guided cart. '''Take care not to set Track Stops at a loading site to dump their contents''', or dwarves will never be able to fill the cart. It will dump any contents the moment they are loaded.

Counter-intuitive to their construction method, Track Stops are considered [[building]]s and must be removed by {{k|q}} {{k|x}}.
* See [[#More_on_Track_stop |More on Track Stops]]

=== Step-by-step tutorial ===

Let's construct a simple minecart route. This route will move stone blocks from an input stockpile to an output stockpile. We'll begin by creating the stockpiles:

[[File:minecart-example-1.png|Stockpiles designated.]]

The input stockpile is on the left; the output stockpile is on the right. We'll be moving blocks from left to right. Disable bins in both stockpiles, and set the input stockpile to accept only from links. Then make the stockpile take from the mason's workshop where the blocks are being produced.

Next, carve the track:

[[File:minecart-example-2.png|Track carving designation.]]

Note that the ends of the designation are uniquely shaped; this is automatic, and not anything you need to control. Now, wait for your engravers to come along and carve the track into the stone. (Your haulers will probably also fill up the input stockpile while you wait.)

In addition, while we're waiting for that to happen, we'll build an iron minecart in the forge.

[[File:minecart-example-3.png|Track carved.]]

When the track has been carved, it will look like the above (the track will be solid instead of flashing). Now, order a track stop to be constructed next to the output stockpile:

{|
| [[File:minecart-example-4.png|Track stop designation.]]
| [[File:minecart-example-5.png|Select dumping direction.]]
|}

You must press {{k|d}} three times to select the dumping direction ''before'' placing the track stop. We want our blocks to be dumped into the output stockpile east of the track stop. Then wait for a mechanic to come along and build the track stop.

[[File:minecart-example-6.png|Track stop constructed.]]

Now we'll define the actual ''route''. This is done in the {{k|h}}auling menu. Press {{k|r}} to begin defining a route. Next, move the cursor to the input end of the track, and then press {{k|s}} to define the first stop:

{|
| [[File:minecart-example-7.png|Stop 1 designation.]]
| [[File:minecart-example-8.png|Route definition, in progress.]]
|}

Move the cursor again, to the output end of the track, and press {{k|s}} again to define the second stop:

{|
| [[File:minecart-example-9.png|Stop 2 designation.]]
| [[File:minecart-example-10.png|Route definition, two stops.]]
|-
|
| [[File:minecart-example-11.png|Stops are not defined yet.]]
|}

There are several user interface features to note at this point. The stops have been positioned, but they haven't been ''defined'' yet, so there is a warning {{DFtext|!|#ff0}} symbol by each of them. In the lower right corner, we see what the {{DFtext|!|#ff0}} means. Also, note that the second stop is labeled in white, while the other two lines are grey. The white text is a selection indicator, and can be moved up and down by pressing {{k|+}}/{{k|-}}.

Next we need to define what our stops do. We want the minecart to be filled with blocks at the first stop, then travel to the second stop where it will dump its cargo, and then return. Press {{k|-}} to move the selection up to stop 1, and {{k|Enter}} to open it up. By default, the stop has three conditions:

[[File:minecart-example-12.png|Default stop definition.]]

We don't want any of these, so press {{k|x}} three times to delete them. This leaves us with a blank stop. Now we can add the conditions we actually want. Press {{k|n}} to begin adding the first condition, then {{k|d}} twice to change the direction from north to east. Then press {{k|c}} to change the condition from empty to full. This will instruct the minecart to be guided east when full of desired items.

To set the desired items, we create a stockpile link. Press {{k|s}}, then move the cursor to the input stockpile, then press {{k|p}} to select that stockpile. Now press {{k|Enter}}; this opens up a selection screen that resembles the stockpile customization screen. Move down to Blocks, {{k|e}}nable them, then (if you wish) restrict it to stone blocks.

When you've done all that, stop 1 should look like this:

[[File:minecart-example-13.png|Stop 1, defined.]]

Stop 2 is much simpler. All we need to do is have the minecart return to the input stop. So, make a condition and change the direction:

[[File:minecart-example-14.png|Stop 2, defined.]]

Finally, we just have to assign our minecart. Go back to the route definition screen, and press {{k|v}}. Select the minecart, and press {{k|Enter}}.

Now we've got everything set up:

[[File:minecart-example-15.png|Route, fully defined.]]

The V is red because the minecart hasn't been moved onto the track yet. Some dwarf will have to haul it from the forge to the first stop, by hand; this will take a while, especially if the forge is far away.

Once the minecart is in place, dwarves should fill it with blocks from the input stockpile, which will in turn be filled with blocks from the workshop where your mason has been toiling dutifully. When the minecart is full, the blocks will be dumped into the 1x1 stockpile on the right. Automatic quantum dumping!

=== Troubleshooting ===

Because of the complexity of the system, all but the most careful and experienced minecart users will encounter issues. Most route issues can be diagnosed and fixed from the {{k|h}}auling menu.

'''Symptom:''' {{DFtext|! Set dir/connect track|6:1}} message appears to the right of one or more stops

'''Possible Causes:'''
* The departure direction of the stop might be invalid. Edit the stop using {{k|Enter}} and press{{k|d}} until it is pointing in a valid direction.
* The track stop might not be built on top of a track. The track stop must be deconstructed to remedy this issue.
* Your track might not be built correctly. Make sure all connected tracks between destinations are not one-way tracks.
** This can be especially confusing with ramps. To carve a two-way track on a (natural) ramp, you must designate the ramp and one square beyond in the direction you want the track to go.
** Ramps '''must''' have a solid block on the side opposite to the track, or they will neither work nor be marked as "unusable". The solid block can be natural or constructed.
* The desired/kept items might not be configured correctly.

'''Symptom:''' The status '''0% V''' always appears to the right of one stop.

'''Possible Causes:'''
* The stop may not be set to take from a stockpile. Edit the Stop using {{k|Enter}} and make sure you see a message like "Take from Stockpile #1".
* The take conditions must correspond with the contents of the stockpile.
* The track stop may be set to dump. A track stop set to dump cannot be filled. You must either set the stop to a time-based departure or deconstruct the track stop and rebuild it without dumping. (Alternatively, with [[DFHack]] you can modify "Dump on arrival" to "No" using the {{key|q}} menu without rebuilding the stop.)
* Make sure the minecart itself has not been designated to be dumped (such as when using mass-dump).

'''Symptom:''' Dwarves fill the minecart properly, but will not move it thereafter.

'''Possible Causes:'''
* The minecart may contain items which are not included in its current stop's desired items. Check inside the minecart using the {{key|k}} and {{key|z}} keys and ensure that all items in the cart are desired items.
* The minecart may contain desired items in bins. Minecarts seem to have problems realizing that they are in fact full of desired items if some of those items are in bins, even if bins are also among the desired items for that stop. '''This cannot be solved by adding the appropriate bins to the stop's desired items.''' Either disallow bins in stockpiles you intend to load minecarts from, or set the departure conditions to rely only on percentage of total load rather than percentage of desired items using the advanced conditions menu ({{key|C}} key).

'''Symptom:''' Dwarves repeatedly attempt to load the minecart, but no items are ever loaded into it.

'''Possible Causes:'''
* This can be caused by using a Track Stop with autodumping enabled at a loading site. Every time a dwarf places an item into a cart resting on such a track stop, the item will be immediately dumped, causing unlimited, useless cart loading jobs. Autodumping Track Stops should never be used at a loading site.

'''Symptom:''' A dwarf picks up the minecart and carries it to its destination.
* See [[#Quirks|Quirks]]

=== Danger ===
Minecarts are not without <strike>danger</strike> [[fun]]. Although designating a track automatically sets the [[traffic]] designation to low, dwarves ''may'' still walk on them, and [[creature]]s ignore traffic designations altogether. If an unlucky dwarf or creature fails to [[dodger|dodge]] a minecart, they can be injured. Most of this danger can be avoided by setting the minecart {{k|h}}auling commands to guide instead of push or ride (dwarves guiding minecarts will ignore traffic restrictions), as well as by [[pasture|pasturing]] domestic animals and preventing the access of other creatures to the tracks. Note that removing the track doesn't reset that tile back to normal traffic priority, so you may wish to manually clean up traffic designation afterward. Also note that bridges that are used as tracks don't have their traffic priority changed automatically (since they're just normal bridges), which could cause dwarves to pathfind normally through dangerous minecart entrances in your fort's walls if you're not careful.

The only <s>fool</s>''dwarf''-proof method is to make the tracks inaccessible. There are several ways to create a track which works for minecarts but doesn't allow creature-traversal; the simplest is perhaps building a [[statue]] on the tracks. Other options include adding single-tile holes (minecarts moving at reasonable speed will jump the gap), vertical drops, minecart-triggered doors, small pools of liquid (4/7 water or 2/7 magma), and hostile creatures overlooking the tracks. For safety, both ends of the track should be isolated, making the dangerous center sections completely inaccessible (though maintenance access can be provided by a locked door).

Danger does not always involve living victims: careless route designation can also result in minecarts careening off tracks or colliding with each other. If this occurs, the [[item]]s may be scattered; this can cause even more hauling jobs than the minecart aimed to eliminate. Even <s>better</s> worse, scattered items, especially [[weapon]]s, can injure passing [[dwarf|dwarves]] or other [[creature]]s; in the words of Toady One the Great, "Accidental grapeshotting of the dining room should be possible now."

Of course, the danger of using minecarts means they can also be [[Trap_design#Minecarts|used as weapons]] by imaginative players.

== Advanced usage and automation ==
Minecart-specific effects are implemented via track stops, rollers and [[pressure plate]]s with "track" condition set. Since all three are considered [[building]]s, they can't be built on the same square (however convenient track stop + pressure plate would be) nor a simple ramp, and are removed by {{k|q}} {{k|x}}.

=== More on Track stop ===
Track stops are constructions that allow further automation of minecart systems via adjustable features such as braking by friction and automatic dumping of contents. They can be built from logs, bars and blocks through {{K|b}} {{K|C}} {{K|S}}; friction amount, dumping toggle and dumping direction must be set '''before''' construction, and these settings can be neither changed nor seen thereafter; however, track stops can be linked to [[pressure plate]]s or [[lever]]s to toggle friction and dumping On or Off (trigger state is inverted: switch On = track stop Off).

If a [[stockpile]] is placed on the tile that a track stop is set to dump to, it can act as a [[Exploit#Quantum_stockpiles|quantum stockpile]] and any items dumped from a minecart that match the storage settings of the stockpile will remain there and accumulate. Normally trackstops are built on top of existing track to operate on moving minecarts, but they can also be used without tracks to create [[Exploit#The_Minecart_Stop|automatic quantum stockpiles]] (see also [[#Step-by-step_tutorial|step-by-step tutorial]]). It is not always desirable to collect ALL of certain items into one quantum stockpile, such as when distributing a material to multiple separate industries. You can link your quantum stockpile to various other stockpiles, ensuring that your dwarves will keep them supplied as necessary. Because quantum stockpiles never fill up like regular stockpiles, it may be a good idea to add a switch to turn them off.

Items dumped from a minecart at a track stop (or dumped by any other means) into open space fall through z-levels until they land on a solid surface. Items falling onto a designated [[stockpile]] will automatically be considered part of that stockpile, even if the stockpile is set to disallow those items (they will, however, be automatically moved to a more appropriate stockpile, if available). Items falling on top of a minecart will '''not''' fall "inside" the minecart. Use with caution; dwarves have fragile skulls.{{bug|5945}}

=== Automated propulsion ===
==== Roller ====
{{Main|Roller}}

A '''roller''' is a [[power]]ed [[machine component]] for the automated propulsion of minecarts. They are built over the top of existing tracks with {{K|b|M|r}}, requiring a [[mechanic]], ''(length/4)+1'' [[mechanism]]s and a [[rope]]. Rollers may also be placed directly on ramps to help pull carts up Z levels. Rollers are very useful to maintain a cart's momentum along long routes, to get them to climb Z-levels without dwarfpower involved, and to get them to reach speeds unattainable by guiding dwarves. These devices are variable-length (1-10), variable-direction and variable-speed ([[Minecart#Numbers_behind_the_scene|see below]]), all traits that can be set at construction time; a roller uses two units of power per tile it is long.

Single-tile rollers transfer power in all four cardinal directions, while other rollers generally only transfer power perpendicular to their activity direction. Longer rollers can also transfer power along their activity direction if built in the correct order, although this can be hard to accomplish and is easily broken. Rollers cannot be powered from above.

Rollers have great acceleration and capped speed. Carts going faster than the roller are unaffected. If a cart moves across an active roller in the direction the roller works and moves slower than the roller's specified speed, the cart will be set to the roller's speed. A cart going against a roller's movement direction will be sent back the way it came (once again at the roller's speed), unless it was moving extremely fast: speed increment of 100000 allows to reverse carts from the full "highest" (50000) speed roller to full "highest" speed back, but ramps can accelerate a cart beyond this. {{cite forum|144328/5702453}}
A cart crossing over a roller perpendicular to its current movement direction will gain the roller's amount of speed in the perpendicular direction without directly changing its forward motion. Without an adjacent wall to constrict its movement, this will typically send a cart off the rails on a diagonal path, completely unable to follow any tracks until it collides with a wall or is otherwise brought to rest. However, if the roller is placed over a track turn and pushes ''from'' the direction of that turn's track, the turn affects carts ''after'' the roller, so they will be forced into the turn rather than derailed in a diagonal direction. {{cite forum|144328/5702453}}

{{diagram|spaces=yes|\
tracks: full:
║ ║
═╗═ ═╢═
║ ║

╢ : roller pushing from W to E
}}
If the roller is powered, carts from ''all'' directions (unless too fast) exit S, because speed imparted by the roller forces carts toward E and ''then'' into the turn.
If not powered, carts from W and N exit S, carts from E and S exit W. Carts above derail speed will ignore the turn, of course.

{{diagram|spaces=yes|\
║ ║
═╗═ ═╟═
║ ║

╟ : Roller pushing from E to W
}}
Carts from the E or W: exit W.
Carts from N: derailed diagonally, exit SW.
Carts from S: derailed diagonally, exit NW.

Rollers affects carts on a track - if placed on a floor or ramp without any tracks, they are ignored. Depowered rollers are also ignored, friction is determined by the tiles underneath.

Because of their one-way nature, rollers are unsuitable for most two-way minecart tracks (unless you set gears toggling roller A->B off while toggling A<-B rollers on). However, a minecart set to be ''guided'' is not affected by rollers at all{{cite forum|109460/3286235}} — this allows a one-way track to be used in both directions. In addition, unpowered rollers do not affect minecarts.

Care must be taken in [[glacier]]s and other extremely cold [[biome]]s, since rollers (and the machinery used to power them) will not operate when constructed on natural [[ice]] floors.

==== Impulse ramps ====
Carts can be given momentum without rollers or changing z-level through a phenomenon called "impulse ramps". A track ramp which is connected both to a wall and to a floor will ''always'' accelerate a cart towards the connected floor tile, no matter where the cart enters the tile from. This means carts can be accelerated as though dropping z-levels, even if the cart doesn't actually change z-level at all. If a track ramp faces three directions such as ╩, then two of those directions need to be facing walls for the cart to be accelerated towards the remaining direction.

Example of straight impulse acceleration:

{{diagram|spaces=yes|\
▒▒▒▒▒▒▒▒▒▒ ▒▒▒▒▒▒▒▒▒▒
═▲▲▲▲▲▲▲▲▲▲═ ═╚╚╚╚╚╚╚╚╚╚═
▒ : Wall
═ : Normal track
▲/╚ : N/E Track/Ramp
}}

If a cart enters from the left, it will speed up on every track/ramp and exit to the right going very very fast - more than one tile every step. If it enters from the right then it will bounce back impulsed by the ramp if it's going slow enough.

As another oddity, carts coming from ramps will in some cases "teleport" through most of the next tile. This can be used to send carts up levels with minimal loss of speed. You can just make an upward spiral alternating impulse ramps and regular upward ramps. It takes no power, is quick and cheap to build, requiring only channeling and track carving, and the cart goes up fast, but not so fast that it launches its contents.

Example of an impulse elevator:

{{diagram|spaces=yes|\
z +0 z +1 z +2 z +3
░░░░░ ░░░░░ ░░░░░ ░░░░░
░╔░░░ ░▼╚╗░ ░░▼▼░ ░░░░░
░╝░░░ ░▼░░░ ░░░╔░ ░░░▼░
░▼▼░░ ░░░░░ ░░░╝░ ░╚╗▼░
░░░░░ ░░░░░ ░░░░░ ░░░░░

░ : Wall
╔,╚,╗,╝ : Track/Ramp
▼ : Down Ramp (empty space)
}}

A sort of opposite effect to impulse ramps also exists: ramps lacking the proper "up" and "down" connections are treated as flat track, even if they actually go up or down z-levels. This allows building "anti-impulse" slopes consisting entirely of ramps only connected up, which a minecart can travel up forty levels and more, needing no more than a single push.

=== Controlling traffic ===

==== Switching ====

As constructions or tile features, [[door]]s and other furniture can be built on tracks. A [[door]] or [[floodgate]] can be turned on or off by a [[lever]], effectively controlling the flow of automated minecarts. This may be <s>dangerous</s> [[fun]], however.
{{diagram|spaces=yes|\
->
A ════┤≡════ B
┤ : roller pushing to East
≡ : door
}}
The roller pushes the cart east, but until the "departure condition" is fulfilled, the door remains closed and blocks the path.

[[Bridge]]s can also act as tracks, but only if they're lowered or not retracted. This property can enable levers to turn tracks on and off. However, care should be taken to ensure that such bridges are never operated while a cart is on top of them, as the cart will be flung off the track. It's worth noting that it's often faster, and cheaper, to construct large bridges than long sections of constructed track.

A powered track switch can be constructed by building an "inverted" corner as illustrated below.
{{diagram|spaces=yes|\
B B
║ -> ║
║ ║
════╚═══ ════├════
A C A C
├ : roller pushing to West.
}}

If the cart is pushed East from the stop at 'A' while the roller is activated, it will arrive at 'B'. If the roller is not running, it will arrive at 'C'. The switch works by the roller first reversing the incoming cart's movement and the cart ''then'' following the track corner.

This switch is very reliable, reacts instantly to on/off signals, and carts of any speed can be switched by this design, although very fast carts will require rollers that are several tiles long, up to three. The requirement for power can be inconvenient or impractical. Non-powered solutions may use controlled derailment, or a connecting bridge.
{{diagram|spaces=yes|\
B ╥
║
║
╞════╝ ════╡
A D C
}}
Here the track between A and C is not continuous. The only continuous track is A->B, with a corner (not a T section). Fast moving carts will tend to derail at D and rejoin the track to C. Placing a door at D will prevent the derailment, so the cart continues to B. The door is operated by mechanisms elsewhere (typically, a lever, but some fun can be had with pressure plates).

Since it depends on derailing, this switch requires a very fast cart, faster than what can be achieved with rollers alone. To gain sufficient speed, a cart must be accelerated further, usually by descending several levels or through impulse ramps. The high speed makes the cart much more dangerous and harder to control.

If carts are moving too slowly to derail at the corner, a retractable bridge may be used as a connector between A and C.
{{diagram|spaces=yes|\
B╥
║
║
A╞════bbb════╡C
}}
The bridge must overlap the corner. Bridges behave like a track crossing, allowing carts to pass in a straight line. When retracted, the corner reappears, so the carts will continue to B. Bridges take 100 steps to react to a signal, necessitating rather long "lead times" when switching tracks via bridge.

As mentioned above, special care must be taken to make sure the bridge doesn't change state while the cart is passing over it. Retracting bridges will throw the cart, causing it to stop dead. Raising bridges can even crush the cart.

==== Controlling Speed ====


Minecarts can reach extremely high speeds, especially when descending multiple Z-levels. A minecart will derail at a track corner if its speed exceeds 0.5 t/st (tiles per step), '''unless''' the route in the direction of travel is blocked:

Will derail at > 0.5 t/st:

{{diagram|spaces=yes|\
in ══╗ -> derailing
║
out
}}

Will not derail at > 0.5 t/st:
{{diagram|spaces=yes|\
in ══╗O
║
out

O : wall/column.
}}

This behavior can be used to build a "speed limiter", that will ensure that when a minecart exits it is traveling below derail speed:
{{diagram|spaces=yes|\
░░░░ ░░░░░ ░░░░░
in ═╔═╗░ ░╔S╗░ ░╔S╗░
out ═╬═╝░ out ═╗═╝░ out ═╗═╝░
░╚S╝░ ░╚═╝═ in ░╚S╝░
░░░░░ ░░░░ ║░░░
in
░ : wall
S : Track Stop (High Friction or lower)
}}
If the minecart is traveling below derailment speed, it will not be affected; if above, will be slowed down and checked again. Granted, you could do the same just with track turns, but it may take a lot of turns and time.

Since all the derailings, bounces and ramps can impart a sideway component of speed small enough to start visible drift many tiles away (say, [[Fun|in the middle of a bridge]]), track turns have one more use: forcing the carts to move strictly along the grid directions. Carts passing a turn below derailing speed convert one component of velocity into another, thus eliminating the drift.

=== Loading liquids ===
[[Water]] and [[magma]] can also be loaded into minecarts by submerging them to a depth of at least 6/7 while standing still or moving at speeds of at most 10000. Loading fluids onto minecarts can be difficult because the added friction provided by fluids can stop a cart in a submerged tile. Curiously, filling a minecart with magma does not injure a dwarf ''riding'' it. A minecart will hold enough fluid to increase the depth of a single tile by 2. This amount is listed as 833 units, which weigh 459Γ (water) or 999Γ (magma). An iron or steel cart filled with magma weighs 1313Γ, while an adamantine cart filled with magma weighs 1007Γ. Since you need a minecart above the liquid's level, possible arrangements may include pressure-activated sluices, rollers (with magma-safe chains for magma), pouring from above to "submerge" it briefly on the same level and drain excess away (dig deeper and leave a vaporizer, though if you could have power for rollers, may as well use a pump) and exploits with ramps (not necessarily impulse ramps, "same height" passing dip does it).
The liquids can be dumped by a constructed track stop.

== Quirks ==
This little quirk concerns dwarf-managed minecarts. If a track which was previously open becomes blocked (ex. flipping a switch connected to a floodgate you've built on the track to raise it) and the conditions for departure are met, instead of refusing to ride/guide the minecart or ride/guide it until it reaches the obstacle, the dwarf will pick up the minecart off the tracks and haul it to its scheduled destination on foot. If the distance is long enough and the weight of the cart heavy enough (due to being filled with heavy items such as stones), the dwarf may drop the cart because of fatigue/hunger/thirst before reaching the destination. This will cancel that vehicle setting job and make another dwarf come by and attempt to haul the cart to the nearest appropriate stockpile where another dwarf will pick up the cart and attempt to haul it to its initial stop. If the stockpile is far enough from initial stop, this second dwarf who is attempting to place the minecart on its tracks may also drop the minecart out of fatigue/hunger/thirst creating a loop that will go on until a dwarf with enough endurance manages to place the minecart where it belongs.

In fact, it seems dwarves are more than happy to attempt to carry a minecart from one stop to another even if just waiting until the track is open again would be the more sane option.

Dwarves will also carry a minecart to its next stop if the direction specified is incorrect (or invalid). This can often occur when using the default departure settings and forgetting to set the direction of each condition.

Dwarves can admire buildings while riding mine carts. Dwarves will not fall asleep during a ride (at least not from being drowsy). If riding on a continuous powered track loop, the dwarf will die of dehydration/starvation as they can not jump off to get sustenance{{cite forum|109460/3377228}}. Dwarves riding in submerged minecarts will gain experience in [[swimming]].{{cite forum|129889}}

Tracks block wagon access to trade depots, unless they're on a ramp. [[Bridge]]s can also be used, as they function as tracks but do not block wagons.

== Physics ==


Minecart physics depend greatly on the departure mode set in the route stop conditions.

When set to "Push" or "Ride", minecarts will move according to the regular laws of momentum, gaining speed when going downhill, losing it slowly due to friction when on a flat plane, and more quickly when going uphill. In these modes, minecarts will move in a straight line until they either are brought to a stop by friction or an obstacle, or until they encounter a turn. A minecart will roll straight past "blocked" ends of T-junctions or track ends, they have no power to restrict a cart's movement. The cart's behavior is largely independent of the weight of its contents (including fluids and dwarves): heavily loaded carts gain more momentum when accelerating, but this only plays a role in collisions: a heavy cart gains just as much speed and is as easy to stop as a light one. In either case, dwarves can not push nor ride an unpowered cart up a ramp, bouncing back the direction it came. At best, this is a waste of time; at worst, it will give your cart-pushing dwarf a [[fun|fun surprise]]. To solve this, the player can either use Rollers (see below) or set the cart to be Guided.

The difference between "Push" and "Ride" is whether the dwarf will go along with the cart or not.
{{DFtext|Push}}: the dwarf will give the cart an initial push, not enough to go up a ramp, but enough to go some way along flat track, and the dwarf will remain at the first stop, ready for a new job.
{{DFtext|Ride}}: the dwarf will give the cart the same initial push and then hop aboard the cart riding with it to the next stop.
{{DFtext|Guide}}: minecarts seem to ignore all laws of physics. That is:
*Ignore the weight of any and all items inside. Therefore:
**Move at the speed of the dwarf that is guiding them. It is thus recommended to pick the most [[attribute#Agility|agile]] of your dwarves for cart-guiding tasks.
*Ignore working rollers.
*Will ''not'' collide with other guided carts even when a full frontal collision would be expected.
*Will go up ramps like nobody's business.
This is therefore the recommended method of transport for simple non-powered rail systems, despite it diverting a dwarf from other, potentially more important tasks.

Some samples with behavior:
{{diagram|spaces=yes|\
A <-> B A <-> C A <-> B
B B B
║ ║ ║
A══╝ A══╩══C A══╬╗
You can only go A->B ╚╝
Works when the cart Works
is in Guide mode.
}}
In the second example above, a cart "pushed" from B will go over the junction and roll off into the unknown south.

=== Track Direction Irrelevance ===
Carts that are traveling independently, (that is, not guided,) only care that tracks ''are'' on the tile, not which direction the tracks actually move. Tracks respect only curves (with two exits) and ramps.

This means, for example, that the following tracks, when a (non-guided) cart travels from West-to-East, are functionally identical in effect:

A════════════B A╬║╚╔╣╩╦╠╥╨╞╡B

This is because so far as the cart is concerned, only ramps and curves with two exits where the exit in the path they are traveling matters.

=== Skipping ===
If a minecart is moving fast enough, it can skip over [[water]] or [[magma]], making splashes of [[mist]] (or [[magma mist]]) as it attempts to move on them horizontally. This horizontal movement is independent of the minecart and its content's [[weight]].

=== Track Jumping ===
If a minecart encounters the end of the track or a T junction with no "exit" in its movement direction, it will simply leave the track and continue on its course in a straight line until it encounters an obstacle, slows to a stop, or encounters another (properly aligned) Track even if the tile at which it joins the new track instantly sends it around a corner.

Tracks that are travelling at high enough velocity will also start "jumping" the track if it hits an un-tracked tile (flying over and ignoring any tracks) until it is ready to land. Carts that land upon tracked tiles re-rail themselves, and clever designers use this feature to jump over curved track sections in one direction or another. (Retracting bridges over untracked tiles can cause jumps or not cause jumps depending upon the status of the bridge.) Minecart speed must be carefully regulated to ensure reliability of jump length.

Carts that approach a downward slope at a high enough velocity will also make a jump, but will not do so if the Checkpoint Effect (below) is exploited through an impulse ramp before the actual downhill as the impulse ramp "tricks" the cart into thinking it has already started going downhill.

=== Invalid Ramps ===
Ramps are functionally defined for cart purposes as being a tile which exerts an acceleration force upon its "downward slope". This downward slope requires a cart to have one ''and exactly one'' carved exit to the tile that is the "bottom" of the ramp. Ramps push carts in this "downward" direction (possibly leading to diagonal movement, below), and the deceleration of an "uphill" ramp is actually just the acceleration being applied against the direction of a cart's movement.

This is where players can find an exploit in the behavior of ramps - if there are ''two'' "downhill" exits to a ramp (such as a "T junction" on a ramp where only one exit faces a wall), then the ramp provides no acceleration ''or'' deceleration, allowing carts to travel up ramps without any loss of momentum except for the standard "flat track" deceleration, because as far as the cart is concerned, the track ''is'' flat. Similar effects can be achieved with a 1-tile "dip" where all exits from a ramp are up another floor.

=== Corner Ramp Derail ===

Corners on upward ramps can cause diagonal movement, forcing a derail even if the cart has a wall next to it, which will force a stop when it touches a wall that forces dwarves to manually reset the cart.

This is caused by the fact that a cart, after turning the bend in the track halfway through the length of the tile, will still "accelerate down", which is now perpendicular to the movement of the cart, causing acceleration to occur in two directions. (Down corner ramps do not have this problem, as when they pass the halfway point, all perpendicular motion is added to forward motion, and after that curve, all downward acceleration is in the forward direction.)

There are two fixes to this problem. One is to simply not put corners on up ramps. The other is to take advantage of the Checkpoint Effect, below, by making a ramp (possibly including an impulse ramp) one tile in front of the ramp to make it skip through most of the tile before sideways momentum can be built.

=== Checkpoint Effect ===
The checkpoint effect, [http://www.bay12forums.com/smf/index.php?topic=144328.0 explained in depth by Larix], is an odd and highly exploitable feature of ramps where minecarts "teleport" through the next tile of track, ignoring nearly all minecart physics (except that they stop at all walls or other obstacles and not only respect curves, but will take them even when they would otherwise derail) and passing through that tile in just a single tick, and into the next tile at the halfway point.

This effect occurs when a cart leaves a downward ramp for any other direction of tile. This allows, for example, two valid straight ramps directly next to one another with a cart dropped onto one or the other with no momentum to have the cart pick up acceleration going "down" the ramp as normal, but then flying up through the "up" ramp it travels into with no loss of momentum, as though it had come from an impulse ramp. If the two ramps had at least one space of distance between them, and then a cart were dropped in, the cart would instead "rock" back and forth between the two ramps.

This seems to be because ramps have a slightly longer length than regular tiles - 144,000, rather than 100,000 distance. When this "snaps back" after a ramp, it seems to project the cart suddenly further along the track, making it jump a tile ahead even when otherwise moving at relatively low speeds.

This effect would be a "[[bug]]" if it weren't probably deliberately coded, and an "[[exploit]]" if it weren't impossible not to feel its effects. Nevertheless, many designs exploit the checkpoint effect to allow "perpetual motion devices" where a cart stuck between two ramps can climb a ramp with no loss in momentum, creating unpowered perpetual motion devices. This also allows for ramp "elevators" to be constructed even without impulse ramps (although impulse ramps make it more compact, still).

Another useful thing to note about this exploit is that carts traveling at no less than 72,000 or so speed (enough to travel half a ramp tile in a single tick) can travel through every tile in just one tick at no change in velocity as long as the tiles alternate between impulse ramp or actual down ramp and any other tile type. The cart checkpoints through the non-down-ramp tiles, and can pass through the (impulse) down ramp tiles in a single tick, before they can actually start gaining momentum.

=== Falling ===
When falling, a minecart appears to cause no damage upon collision, possibly to allow cart "stacking" across Z-levels.{{cite devlog|2012|04|06}} A dwarf riding in a minecart that is dropped multiple z-levels suffers normal fall damage. Minecarts can fall through up/down stairs.
The cart falling (from a hatch, thus with no horizontal speed) onto a track ramp is accelerated as if starting from the middle of the ramp - i.e. to the same speed, no matter how many Z-levels it was dropped, vertical velocity is negated. {{cite forum|144328/5701211}}

=== Stacking ===
If a minecart lands on top of another minecart, they may form a stack, with the upper cart on the z-level above the lower. Subsequent carts do not form a stack, but rather quantum stockpile in the same space. This behaviour is useful for [[megaprojects]] and [[trap design]] with minecarts as the weaponry. Moderation should still be exercised: carts take longer to fall into a "stacking" tile already occupied by other carts and will spend that time "hanging" in the air above the stack. This can lead to following carts striking them, which can cause all kinds of malfunctions. The extra time is two game steps for every cart already in the stack, which doesn't hurt stacks of ten carts very much but makes stacks of 100+ rather impractical.

These minecarts on the upper level generally need to be struck with another minecart to move out, or have their support removed. The latter option is safest done by shooting it away with another minecart, manual removal of a stack-supporting cart typically causes the next cart from the stack to [[fun|fall on top]] of the hauler.

=== Perfectly Elastic Collisions ===
Minecart collisions are perfectly elastic, meaning that not only do minecarts not take damage, but that two carts that are rolling which have frontal collisions of near-similar speed, and where one cart is no more than twice the mass of the other cart, will result in a billiard-ball-like effect of the lighter cart bouncing off the heavier cart with a proportional speed increase dependent upon the relative momentum behind the heavier cart.

Using this trick with carts already at the 270,000 maximum speed from ramps can result in "supersonic" carts traveling at speeds in the millions (travelling a dozen tiles per tick), but where they are suddenly subject to 10,000 units of "terminal velocity" friction per tick. [http://www.bay12forums.com/smf/index.php?topic=137557.0 Thread with SCIENCE here].

While hypothetically capable of launching a minecart into orbit when used in conjunction with a ramp, no cargo can be contained in the launched cart, as the collisions will force ejections of the cargo. Your "unwilling volunteer" [[goblin]] space pioneers will simply become paste underneath the wheels of an extreme high-speed cart.

=== Numbers behind the scene ===

According to early research by '''expwnent'''{{cite forum|112831/3536975}}:

The minecart has a variable for speed. Speed is measured in tiles/100000 ticks, so a speed of one hundred thousand means one tile per tick. By going down a large number of ramps, a maximum speed of 270,000 can be reached, which presents the limit for most practical applications. Short bursts of (much) higher speeds are possible through carefully planned collisions of high-speed carts {{cite forum|137557/5145499}}.

Every tick the cart accumulates distance units, as well as slows down depending on current tile (speed is reduced by "friction" of the tile). The cart will move to the next tile the tick before accumulating 100000 distance units, (or several tiles in case of great speed), then the leftover distance units are added to the default 100000 distance u. of the next tile. Since most deceleration and acceleration is applied per step, with the notable exception of corners, a cart going at twice the speed of another one can cover about four times the distance in a straight line, but only twice the distance along a winding track with very many corners.

A push will teleport a cart to the beginning of the next tile (NOT the middle!) in one tick with 19990 speed (10 speed is lost due to track friction), while a roller will give a cart the roller's set speed, and it will start to accumulate regular track friction past the middle of the roller tile. Some track features will affect a minecart when it is past the middle of the previous tile: entering a ramp or a hole/drop will happen when the cart has left the middle of the previous tile, and the ramp will gain additional distance unit depending on the leftover units from the previous tile. When a cart leaves a ramp it will emerge after one tick in the middle of the next regular tile, so its entry coordinate is "50000-speed+friction". Rollers also affect the speed of minecart from the middle of the previous tile.

Friction of tiles:
{| class="wikitable"
|-
! Tile
! Friction
! Comment
|-
| Tracks
| 10
|-
| Ground/Floor
| 200
|-
| Unusable ramp
| 10
|-
| Upwards ramp
| 4910 (10+4900)
|-
| Downwards ramp
| -4890 (10-4900)
|-
| Roller
| ±100000 (but capped by the set speed)
|-
| Corner track
| 10
| Speed reduced by 1000 upon leaving the corner tile
|-
| Track stop (highest)
| 50000
|-
| Track stop (high)
| 10000
|-
| Track stop (medium)
| 500
|-
| Track stop (low)
| 50
|-
| Track stop (lowest)
| 10
|-
| Water 1-6
| Additional (WaterLevel - 1) * 100
| rowspan="2" | [[#Skipping|See Skipping]]
|-
| Magma 1-6
| Additional (WaterLevel - 1) * 500
|-
| Empty space
| 0
|}

Water of depth 7/7 provides a friction of about 10000 per step, as does maximum-depth magma. This higher friction may not apply to very slow-moving carts.

Impulse sources:
{| class="wikitable"
|-
! Feature
! Speed
|-
| Push
| 20000
|-
| Roller lowest
| 10000
|-
| Roller low
| 20000
|-
| Roller medium
| 30000
|-
| Roller high
| 40000
|-
| Roller Highest
| 50000
|-
|}

== Non-standard uses ==
Minecarts include some interesting characteristics that have motivated uses beyond hauling. They can be useful for creating fully-automated [[exploit|quantum stockpiles]] and [[garbage disposal]]s. Storing perishable goods (meat, meals, etc.) inside a minecart appears to guard against rot and vermin.
Minecarts can be [[Trap_design#Minecarts|used as weapons]], or as (hopefully non-fatal) triggers to restart stalled [[healthcare]]. They can also be used to time/control game events, either using a basic [[repeater]] or much more advanced [[minecart logic]].
Minecarts trigger [[pressure plate]]s, which means a trap can be designed to trigger when a thief attempts to steal a minecart.
A pressure plate can be used as automatic and more precise custom "launch when full enough" system - as long as weight of your minecarts stays the same. You cannot build a hatch or roller on the same tile, so launch by bumping with another cart. {{cite forum|15096/4580050}}
Dwarves riding minecarts can attack enemies within reach (which goes back to dev log). This applies to shooting, and they actually can hit targets while riding by.{{cite forum|109460/5266119}} Whether a minecart protects the rider and how it interacts with dodging is not known yet. Minecart riders can also [[Swimming#Minecart_training|train swimming]] and [[Megaprojects#Surveillance_Track|detect ambushers]].

== Adventure mode ==
In addition to being used for hauling, minecarts can also be ridden in [[adventure mode]]. (Adapted from forum thread {{cite forum|122903/4258212}})

# If the minecart is in your inventory, drop it. If it is already on the ground, proceed to step 2.
# Press {{k|u}} when you are 1 tile away from the minecart (or standing on the same tile as the minecart).
# You will be presented with the following options:
[[File:minecart adventure mode menu.png|left]]
{{clear}}
* If you {{DFtext|Push}} the minecart, it will move a few tiles in the direction you chose. Physics comes into play here, so it will gain/lose speed depending on the usual factors.
* If you {{DFtext|Ride}} the minecart, you will hop into the minecart, even if you were a tile away, and it will move in the chosen direction with you in it. It will gain/lose speed depending on the usual factors. Whilst the minecart is in motion, you should press {{k|.}} to skip your turn; if you attempt to move whilst the minecart is still in motion, the laws of physics come into play, and you will take [[wound|damage]]. Alternatively, you can push the minecart whilst it's still in motion (although it's unclear how one can bend [[physics]] so as to push a moving minecart whilst inside the minecart). If you push it in the same direction you are already travelling in, you will greatly increase the minecart's velocity. You can also push it in different directions, and this will cause it to gradually change direction-the amount of pushes this requires depends on the minecart's velocity. Once the minecart has stopped moving, you may move out of it safely, or you may want to give it another push. Note that if you push a minecart right after having ridden it (still on the same tile as the minecart), it will act as though you chose to ''ride'' it.

If you want to test this out without creating an adventurer, the [[object testing arena]] allows you to spawn minecarts ({{k|k}}-{{k|c}}-{{k|n}})

== Forging and Melting ==
* Metal minecarts cost '''two''' [[metal]] bars to forge, or '''six''' [[adamantine]] wafers.
* When a non-adamantine metal minecart is melted down, it will return '''1.8''' metal bars, for an '''efficiency of 90%'''.
* When an adamantine minecart is melted down, it will produce '''1.8''' wafers, for an '''efficiency of 30%'''.

== See also ==
* [http://www.bay12forums.com/smf/index.php?topic=109460.0 The "How Does Minecart" Thread] by '''Girlinhat''' et al.
* [http://www.bay12forums.com/smf/index.php?topic=112831.0 SCIENCE: Quantifying minecart physics] by '''Snaake''' et al.
* [http://www.bay12forums.com/smf/index.php?topic=129676.0 How to build a Multi-cart Ore to Magma Minecart Project without needing power] by '''WanderingKid'''.
* [http://www.bay12forums.com/smf/index.php?topic=144328.0 My very own Minecart Education Thread. Ten Lessons, now complete.] by '''Larix'''.

== Bugs ==
*A dwarf will drop her [[child|baby]], if she has one, when boarding a minecart set to be ridden.
*Dwarves have no concept of traffic safety and will walk into busy minecart lines to retrieve objects, often with deadly consequences. This is especially problematic in [[Swimming#Minecart_training|clever applications]] depending on dwarves riding the carts very frequently, because they have a bad habit of dumping their worn clothes on the tracks after a minecart ride. Adding an automatically-operated [[hatch cover]] at the end of such a ride can help prevent [[unfortunate accident]]s.
*Dwarves cannot guide a minecart through an unlocked door unless another dwarf opens the door.{{bug|6056}}
*It is possible for a creature and minecart moving towards each other to pass without collision if they exchange tiles in the same tick.
*After a minecart ride, a dwarf will sometimes haul the minecart to a storage stockpile, leaving another dwarf to haul the vehicle back to the route.
*Minecarts falling onto a floor injure creatures in the tile below the floor.{{bug|6068}}
*A minecart's initial velocity is not affected by weight, when pushed or launched from rollers.{{bug|6296}}
*Removing a stop that has a vehicle waiting on it may cause the game to crash.{{bug|5980}}

{{Category|Fortress mode}}
{{Category|Interface}}

[[ru:Minecart]]

Minecart

2015-06-18T01:11:25Z

NW Kohaku: /* Physics */

{{Quality|Masterwork|08:15, 19 May 2015 (UTC)}}
{{av}}
A '''minecart''' is a [[tool]] intended for [[hauling]], introduced in version 0.34.08. It can be made of [[wood]] at a [[carpenter's workshop]] or [[metal]] at a [[metalsmith's forge]] (using the [[Metal crafter|metalcrafting]] labor.) Minecarts store up to five times as many items as [[wheelbarrow]]s and are quite a bit faster than dwarves hauling objects by hand, but have the disadvantages of requiring a dedicated track network, a complex route planning phase, and the possibility of dwarves [[Fun|blundering into the path of carts filled with lead ore]]. Tracks may be carved into stone, or [[Construction|constructed]]; the latter allows above-ground routes, but these are more difficult to set up due to their additional [[building material|material requirements]].

Just like wheelbarrows, minecarts are considered [[item]]s and are stored in a [[furniture]] [[stockpile]]. Despite their five-times-greater capacity, they are only 33% larger than wheelbarrows and are identical in base [[item value|value]] when made from the same [[material]] (the value may differ due to the [[item quality]]). [[thief|Thieves]] or even mischievous animals can steal minecarts, even when they are moving on a track{{cite forum|109460/3289070}}. However, minecarts moving fast enough or being ridden cannot be stolen.

Although most of the utility of minecarts is in [[fortress mode]], an [[adventure mode|adventurer]] can also ride in a minecart. Adventurers can also pick up and relocate minecarts.

The invention of minecarts revolutionized the [[minecart logic|Science of Dwarfputing]] by enabling smaller, faster logic systems to be built.

== Basic Minecart Usage ==
Minecarts can be used to swiftly transport dwarves, [[flow|fluids]], and/or large amounts of items, but before you have a functional minecart there are several preconditions that need to be met. First of all you need an actual minecart, constructed either in a [[carpenter's workshop]] or [[metalsmith's forge]]. For the minecart to be able to move you also need to carve (with {{k|d}} {{k|T}}) or construct (with {{k|b}} {{k|C}} {{k|T}}) a track, which could be as simple as a straight line. Finally you need to construct stops on your track (with {{k|b}} {{k|C}} {{k|S}}) where the minecart will start and stop.

After you have created the stops and assigned a cart to the track, you must create logic routes connecting several stops and designate starting conditions for each stop. This is done with the {{k|h}}auling key. The most basic conditions are how the cart's movement is initiated and in which direction the cart should start moving. Carts can be either be Pushed (a dwarf stands at a stop and gives the cart a single push) or Guided (a dwarf continually pushes the cart forward, guiding it along the track). The [[hauling]] [[labor]] required for pushing and guiding carts is called "Push/Haul Vehicles" and is turned on by default.

To control which items to transport you can add conditions specifying: (1) which kind of items to be loaded, and unloaded, (2) stockpile links to define which stockpile(s) the items should be un/loaded to and from.

===Capacity and weights ===
Minecarts have five times the [[Weight|capacity]] of [[wheelbarrow]]s.

'''Examples of the capacity of one cart'''
{| class="wikitable"
|-
! Item
! Amount
|-
| [[stone]]
| 5
|-
| [[wood|log]]
| 10
|-
| [[block]]/[[bar]]
| 83
|-
| [[Kitchen|prepared meals]]
| 500
|-
| [[Trap_component#Spiked_ball|spiked balls]]
| 500
|-
| [[Weapon#Native_weapons|mace]]
| 625
|-
| [[Weapon#Native_weapons|spears]]
| 1250
|-
| [[cloth]]
| 2500
|}

The weight of the loaded minecart does not affect the initial velocity received from pushing or launching from a roller. However, the load of a minecart ''does'' affect whether a [[pressure plate]] triggers or not, based on the pressure plate's setting.

'''Weights of different carts'''

{| class="wikitable"
|-
! Type of cart
! Empty cart
! Fully loaded (items)
|-
| oaken minecart
| 28Γ
| 378Γ (10 oak logs)
|-
| platinum minecart
| 856Γ
| 10482Γ (83 gold bars)
|}

The weight of a minecart is one twenty-fifth (1/25) the [[density]] of its material in Urists. Because pressure plates can be set to trigger at intervals of 50 Urists, minecarts with weights just under a multiple of 50 are ideal for switching based on whether they're full or empty. The best minecart materials for full/empty switching are as follows:

{| class="wikitable sortable"
|-
! Material !! Minecart weight !! Content weight required to trigger !! Banana roasts required to trigger (for scale)
|-
| [[Bismuth]] (moods only) || 391 || 9 || 15
|-
| [[Brass]] || 342 || 8 || 14
|-
| [[Electrum]] || 596 || 4 || 7
|-
| [[Fine pewter]] || 291 || 9 || 15
|-
| [[Glumprong]] || 48 || 2 || 4
|-
| [[Lay pewter]] || 291 || 9 || 15
|-
| [[Nickel silver]] || 346 || 4 || 7
|-
| [[Tin]] || 291 || 9 || 15
|-
| [[Trifle pewter]] || 291 || 9 || 15
|}

=== Creating tracks ===
Minecart tracks are made up of contiguous track, tracked ramp, or bridge tiles. Track tiles and tracked ramp tiles have a direction or series of directions associated with them. These directions dictate which directions a minecart on a given tile may move from that tile. For example, a Track NE (northeast) tile allows a minecart on it to move either north or east from its present position. Therefore, if you want your minecart to move east along a straight piece of track, then return west using that same track, you would need to use EW tracks so that the cart could travel east initially, then return west over the same track. Excluding designs in which the cart will "jump" tracks via a drop or other ramp, tracks must be valid end to end to work for most looped or straight-track applications. A single east only track tile in your line of east-west tracks will cause any route using the track to fail the moment it tries to go the wrong way over that tile. Minecart tracks can be built in two ways: Engraved/carved or constructed. A given minecart track need not use engraved or constructed elements exclusively, as the two methods can be used interchangeably depending on the needs of a given section of track. The way the tracks are built is slightly different between the two, as explained below.

====Simple tracks====

'''Carved'''

A single-tile wide strip of natural stone can be designated to be [[Engraver|carved]] (with {{K|d}} {{k|T}}), which will create a straight two-way track. The creation of corners, crossings, and T-junctions is as simple as designating another strip of track that overlaps an existent or newly designated track. Engraved tracks are removed by [[smoothing]] the rock they're on, which results in a smooth floor (that can be re-engraved if necessary), or by building a [[floor]] on top and subsequently removing it. Dwarves can carve corner tracks in one pass by designating the track carving twice and canceling unwanted carvings (with {{K|d}} {{K|x}}). Tracks can be engraved in any natural floor tile, rough, smooth and even over engravings, providing an easy method to remove low-quality or undesired floor engravings. Once a track has been engraved, it's important to check the track directions for each tile in the route carefully to make sure no mistakes were made by yourself or the game's track engraving logic.

'''Constructed'''

Tracks can also be built as regular [[construction]]s (through {{K|b}} {{K|C}} {{K|T}}). This method is resource-expensive, since each track tile requires one stone, [[bar]], or [[block]] for construction, and time-consuming, since you can't designate strips longer than 10 tiles at a time. Corners, crossings, T-junctions, and ramps also have to be designated individually. However, it is usually the only way to build tracks above ground or on soil (barring the [[Obsidian farming|creation of obsidian]]). Constructed tracks are designated for removal like any regular construction; be aware that removing track ramps built on top of natural ones will also remove the original ramp, leaving a flat floor.

====Ramps====

'''Carved'''

The carving of natural ramps is a little more confusing: to carve a two-way track on a ramp (natural only, does not work on constructed ramps), you must designate the track '''starting on the ramp and one square beyond''' in the direction you want the track to go. For the side of the ramp square you want to head upward, there '''must''' be either a natural or constructed wall in the square next to it, otherwise the game assumes you are trying to carve it on the same level -- this can result in the track being carved underneath a door or other object. If you have accidentally done this, you can correct it by smoothing the ramp and constructing a single square of wall next to it, then re-carving the ramp correctly. (However, the wall must stay there permanently; removing it will disconnect the track.)

'''Constructed'''

When constructing track ramps, the stated direction should be the same as the connected tracks. For example, a track going up from West to East would require, starting from the West, a Track (EW), a Track/Ramp (EW) and a Wall behind the ramp, underneath the section of track above it. Incorrectly placed ramps result in minecarts ignoring the ramp and crashing into the supporting wall. They will not, however, display as unusable as when the supporting wall is missing.

'''Examples of ramps'''

A simple ramp would look like this:
{{diagram|spaces=yes|\
z +0 z +1
░░░░ ░░░░
═▲o ░▼═
░░░░ ░░░░
o : wall
}}

Carving track corners into ramps is rather unintuitive and complicated. Since engraving tracks always requires two tiles to connect in a straight line as input, you have to give two separate designations for a single job: a track bit from the ramp tile to the "below" direction and another one to the wall of the "upward" direction. If you wanted to change direction on a ramp from east to north:
{{diagram|spaces=yes|\
z +0 z +1
░░░░░ ░░░░░
░░░░░ ══╗░░
=▲░░ ░░▼░░
░░░░░ ░░░░░
}}
you would need to connect the ramp on z +0 both to the west and to the north by issuing two "carve track" commands, one selecting the ramp and the track tile to the west, and another connecting the ramp tile with the wall to the north. An engraver would then carve a NW track corner into the ramp, allowing carts to pass the corner correctly both going up and down. Such track corners are perfectly serviceable for guided carts, but moving down a route of several of them by pushed or ridden cart is problematic - ramps on corners behave very counter-intuitively, resulting in loss of speed when going down and diagonal movement when going up.

Moving to and from ramps (or between ramps "pointing" in different directions0 causes some non-trivial adjustments to speed and even moving along the tiles at a fixed speed ''unrelated to the entry/exit velocity values'', because transitions to/from ramps are processed differently and are not to be "skipped". This affects compact track/ramp combinations (such as e.g. a simple 2x2 ramp spiral) most, and combined with bouncing often makes them work not in the way one could expect. {{cite forum|144328/5705102}}

{{anchor|Tracks}}

=== Hauling route ===
A hauling route is a list of directions describing how and under what conditions a minecart will move. The proper setting up of routes is essential for a working rail system. Routes, stops, departure conditions and stockpile links are managed from the {{k|h}}auling menu.

==== Route ====
A route defines the path a minecart will take along a track, as well as under what conditions it will move or stop moving. A route is made up of stops. Stops are precisely what they sound like, a position on the track at which you want a minecart to stop. A minecart track might use as little as a single stop for a looped track, which will serve as both a starting and stopping point for the cart, or it could contain many stops, perhaps to load supplies or wait for a bridge to be manually lowered, before reaching its destination or returning to its starting point. It is important to note that you only need to place stops on a route where you actually want the cart to stop and wait for some action to occur. They are not needed to help navigate the cart along the track beyond telling it where on the track to stop.

New routes are created with the {{k|h}}auling key. Existing ones can be removed (without confirmation) with the {{k|x}} key, and also {{k|n}}icknamed. Before operating, the route must have a {{k|v}}ehicle assigned to it (this can be done with either the route or a stop selected). Assigning a full minecart to a route may result in a slow hauling job if the contents are heavy.

==== Stops ====
Stops are the individual waypoints that make up a hauling route. A given stop consists of the location of a tile, as well as conditions describing when, where, and how a cart should be moved after being stopped at that tile. Stops can be created from within the {{k|h}}auling menu, by placing the cursor over a tile and hitting {{k|s}} while highlighting the route (or a stop within) you've already designated. A minecart will begin its route at the first stop created, and continue through each subsequent stop, being guided, pushed, or ridden from each stop to the next depending on the conditions specified. In many basic minecart applications, the cart will end up at the same stop it began at, though this is not always the case. It is important to note that hauling stop order is enforced, even if there is no track. A dwarf will drag the cart overland back to a skipped stop in the route's list if your tracks bypass it somehow.

Once a stop has been placed, it is given a default set of conditions under which to move the minecart if it is stopped there. Each new stop gets the same default conditions regardless of the track it is placed upon (e.g. guide the cart to the north). For this reason new stops might get marked by yellow exclamation marks ({{DFtext|!|#ff0}}) due to invalid directions. One important thing to note is that as you place additional stops, the display will show paths between the stops you have defined. However, this is '''not''' necessarily the actual route the minecart will take once the route is in operation. For example, if a route were defined with two stops at opposite ends of a track with many twists and turns, a line will be drawn directly between those stops to show the order in which they will be visited. These route lines may crisscross all over the tracks, but so long as the track is valid end to end, the cart will follow the track from one stop to the next, even across twists, turns, and z-level changes. Stops, which are the steps that make up a route, should not be confused with Track Stops, described below.

===== Stockpile links =====
By placing the cursor on top of a stockpile and using {{k|s}}, you can create stockpile links while defining a hauling stop. Links can also be redefined by selecting them, placing the cursor over a different stockpile, and pressing {{k|p}}. The cart will then be filled by items present in its various linked stockpiles in preference to other items. Note that bins should be used with caution in stockpiles that are linked to minecarts. Bins cause problems when used with the "Desired Items" list in a stop's conditions. For example, if a minecart is set to accept only granite blocks, and to depart north when it is 100% full of granite blocks, it will not depart if any of those granite blocks are in bins, even if bins are also included in the desired items list. Two solutions to this problem exist as of v0.40.24. First, bins can be disallowed in stockpiles that are linked to stops. Alternatively, bins '''can''' be used in conjunction with minecarts provided that the minecart's departure conditions use only "any items" instead of "desired items." This option can be toggled in the advanced conditions menu for a stop, accessible via the {{key|C|}} key. The cart's contents can still be controlled by specifying what items are allowed in the linked stockpile.

===== Departure condition =====
Departure conditions involve setting conditions in which the minecart will leave on the route. Each condition includes:
# A departure mode (Guide, Ride or Push).
# An initial departure direction (NSEW). Note that this defines the initial direction of movement only. Even if a track includes many turns, as long as the initial movement direction is valid the cart will follow the minecart track thereafter.
# A timer, before which the departure condition cannot be met.
# Conditions on the amount of items in the cart.
Departure conditions are created with the {{k|n}} key. A new departure condition will read: "guide north immediately when empty of desired items". This condition can be changed between basic presets with {{k|c}}. "Advanced" mode ({{k|C}}) allows for more precise control over departure conditions: fine tuning the percentage from 0 to 100 in 25% steps ({{k|f}} and {{k|F}}), switching it being either the maximum or the minimum amount of items for the condition to be met ({{k|m}}), and whether the cart accepts all or only a specific set of items ({{k|l}}). Common to both screens are the departure mode ({{k|p}}, Push, Ride or Guide), {{k|d}}irection, and timer ({{k|t}} and {{k|T}}) options.

To have a cart only carry a specific set of items, the stop can be set to only carry "desired" items, opening the selection screen with the {{k|Enter}} key while having said stop condition selected, and toggling as desired, or it can simply be linked to a stockpile and set to depart once it is full of items from its linked stockpiles, regardless of type.

=== Track Stops ===
A Track Stop, not to be confused with a route stop, is an optional, single-tile construction which serves two purposes. First, it can be used to cancel a cart's momentum in order to slow or stop it as it passes over the Track Stop. This might be necessary if a cart were pushed down a series of ramps to its destination. Second, a Track Stop can cause a cart to automatically dump its contents as it passes over the Track Stop. Track Stops are constructed via {{k|b}} {{k|C}} {{k|S}}, and must be constructed atop an existing piece of track. If a Track Stop has been set to automatically dump a cart's contents, the cart will dump its contents in the direction indicated when it passes over the Track Stop. Depending on the friction settings chosen for the Track Stop, the cart might then stop after dumping, or it might continue on its route to another destination.

Track Stops are not mandatory; in fact, their main use is in automated rail systems. However, even in basic rail systems it can be useful to set a Track Stop to dump items: this saves time that dwarves would otherwise spend in removing items from the cart, time that is better spent driving the cart back to where it's needed. Dumping will occur even with a guided cart. '''Take care not to set Track Stops at a loading site to dump their contents''', or dwarves will never be able to fill the cart. It will dump any contents the moment they are loaded.

Counter-intuitive to their construction method, Track Stops are considered [[building]]s and must be removed by {{k|q}} {{k|x}}.
* See [[#More_on_Track_stop |More on Track Stops]]

=== Step-by-step tutorial ===

Let's construct a simple minecart route. This route will move stone blocks from an input stockpile to an output stockpile. We'll begin by creating the stockpiles:

[[File:minecart-example-1.png|Stockpiles designated.]]

The input stockpile is on the left; the output stockpile is on the right. We'll be moving blocks from left to right. Disable bins in both stockpiles, and set the input stockpile to accept only from links. Then make the stockpile take from the mason's workshop where the blocks are being produced.

Next, carve the track:

[[File:minecart-example-2.png|Track carving designation.]]

Note that the ends of the designation are uniquely shaped; this is automatic, and not anything you need to control. Now, wait for your engravers to come along and carve the track into the stone. (Your haulers will probably also fill up the input stockpile while you wait.)

In addition, while we're waiting for that to happen, we'll build an iron minecart in the forge.

[[File:minecart-example-3.png|Track carved.]]

When the track has been carved, it will look like the above (the track will be solid instead of flashing). Now, order a track stop to be constructed next to the output stockpile:

{|
| [[File:minecart-example-4.png|Track stop designation.]]
| [[File:minecart-example-5.png|Select dumping direction.]]
|}

You must press {{k|d}} three times to select the dumping direction ''before'' placing the track stop. We want our blocks to be dumped into the output stockpile east of the track stop. Then wait for a mechanic to come along and build the track stop.

[[File:minecart-example-6.png|Track stop constructed.]]

Now we'll define the actual ''route''. This is done in the {{k|h}}auling menu. Press {{k|r}} to begin defining a route. Next, move the cursor to the input end of the track, and then press {{k|s}} to define the first stop:

{|
| [[File:minecart-example-7.png|Stop 1 designation.]]
| [[File:minecart-example-8.png|Route definition, in progress.]]
|}

Move the cursor again, to the output end of the track, and press {{k|s}} again to define the second stop:

{|
| [[File:minecart-example-9.png|Stop 2 designation.]]
| [[File:minecart-example-10.png|Route definition, two stops.]]
|-
|
| [[File:minecart-example-11.png|Stops are not defined yet.]]
|}

There are several user interface features to note at this point. The stops have been positioned, but they haven't been ''defined'' yet, so there is a warning {{DFtext|!|#ff0}} symbol by each of them. In the lower right corner, we see what the {{DFtext|!|#ff0}} means. Also, note that the second stop is labeled in white, while the other two lines are grey. The white text is a selection indicator, and can be moved up and down by pressing {{k|+}}/{{k|-}}.

Next we need to define what our stops do. We want the minecart to be filled with blocks at the first stop, then travel to the second stop where it will dump its cargo, and then return. Press {{k|-}} to move the selection up to stop 1, and {{k|Enter}} to open it up. By default, the stop has three conditions:

[[File:minecart-example-12.png|Default stop definition.]]

We don't want any of these, so press {{k|x}} three times to delete them. This leaves us with a blank stop. Now we can add the conditions we actually want. Press {{k|n}} to begin adding the first condition, then {{k|d}} twice to change the direction from north to east. Then press {{k|c}} to change the condition from empty to full. This will instruct the minecart to be guided east when full of desired items.

To set the desired items, we create a stockpile link. Press {{k|s}}, then move the cursor to the input stockpile, then press {{k|p}} to select that stockpile. Now press {{k|Enter}}; this opens up a selection screen that resembles the stockpile customization screen. Move down to Blocks, {{k|e}}nable them, then (if you wish) restrict it to stone blocks.

When you've done all that, stop 1 should look like this:

[[File:minecart-example-13.png|Stop 1, defined.]]

Stop 2 is much simpler. All we need to do is have the minecart return to the input stop. So, make a condition and change the direction:

[[File:minecart-example-14.png|Stop 2, defined.]]

Finally, we just have to assign our minecart. Go back to the route definition screen, and press {{k|v}}. Select the minecart, and press {{k|Enter}}.

Now we've got everything set up:

[[File:minecart-example-15.png|Route, fully defined.]]

The V is red because the minecart hasn't been moved onto the track yet. Some dwarf will have to haul it from the forge to the first stop, by hand; this will take a while, especially if the forge is far away.

Once the minecart is in place, dwarves should fill it with blocks from the input stockpile, which will in turn be filled with blocks from the workshop where your mason has been toiling dutifully. When the minecart is full, the blocks will be dumped into the 1x1 stockpile on the right. Automatic quantum dumping!

=== Troubleshooting ===

Because of the complexity of the system, all but the most careful and experienced minecart users will encounter issues. Most route issues can be diagnosed and fixed from the {{k|h}}auling menu.

'''Symptom:''' {{DFtext|! Set dir/connect track|6:1}} message appears to the right of one or more stops

'''Possible Causes:'''
* The departure direction of the stop might be invalid. Edit the stop using {{k|Enter}} and press{{k|d}} until it is pointing in a valid direction.
* The track stop might not be built on top of a track. The track stop must be deconstructed to remedy this issue.
* Your track might not be built correctly. Make sure all connected tracks between destinations are not one-way tracks.
** This can be especially confusing with ramps. To carve a two-way track on a (natural) ramp, you must designate the ramp and one square beyond in the direction you want the track to go.
** Ramps '''must''' have a solid block on the side opposite to the track, or they will neither work nor be marked as "unusable". The solid block can be natural or constructed.
* The desired/kept items might not be configured correctly.

'''Symptom:''' The status '''0% V''' always appears to the right of one stop.

'''Possible Causes:'''
* The stop may not be set to take from a stockpile. Edit the Stop using {{k|Enter}} and make sure you see a message like "Take from Stockpile #1".
* The take conditions must correspond with the contents of the stockpile.
* The track stop may be set to dump. A track stop set to dump cannot be filled. You must either set the stop to a time-based departure or deconstruct the track stop and rebuild it without dumping. (Alternatively, with [[DFHack]] you can modify "Dump on arrival" to "No" using the {{key|q}} menu without rebuilding the stop.)
* Make sure the minecart itself has not been designated to be dumped (such as when using mass-dump).

'''Symptom:''' Dwarves fill the minecart properly, but will not move it thereafter.

'''Possible Causes:'''
* The minecart may contain items which are not included in its current stop's desired items. Check inside the minecart using the {{key|k}} and {{key|z}} keys and ensure that all items in the cart are desired items.
* The minecart may contain desired items in bins. Minecarts seem to have problems realizing that they are in fact full of desired items if some of those items are in bins, even if bins are also among the desired items for that stop. '''This cannot be solved by adding the appropriate bins to the stop's desired items.''' Either disallow bins in stockpiles you intend to load minecarts from, or set the departure conditions to rely only on percentage of total load rather than percentage of desired items using the advanced conditions menu ({{key|C}} key).

'''Symptom:''' Dwarves repeatedly attempt to load the minecart, but no items are ever loaded into it.

'''Possible Causes:'''
* This can be caused by using a Track Stop with autodumping enabled at a loading site. Every time a dwarf places an item into a cart resting on such a track stop, the item will be immediately dumped, causing unlimited, useless cart loading jobs. Autodumping Track Stops should never be used at a loading site.

'''Symptom:''' A dwarf picks up the minecart and carries it to its destination.
* See [[#Quirks|Quirks]]

=== Danger ===
Minecarts are not without <strike>danger</strike> [[fun]]. Although designating a track automatically sets the [[traffic]] designation to low, dwarves ''may'' still walk on them, and [[creature]]s ignore traffic designations altogether. If an unlucky dwarf or creature fails to [[dodger|dodge]] a minecart, they can be injured. Most of this danger can be avoided by setting the minecart {{k|h}}auling commands to guide instead of push or ride (dwarves guiding minecarts will ignore traffic restrictions), as well as by [[pasture|pasturing]] domestic animals and preventing the access of other creatures to the tracks. Note that removing the track doesn't reset that tile back to normal traffic priority, so you may wish to manually clean up traffic designation afterward. Also note that bridges that are used as tracks don't have their traffic priority changed automatically (since they're just normal bridges), which could cause dwarves to pathfind normally through dangerous minecart entrances in your fort's walls if you're not careful.

The only <s>fool</s>''dwarf''-proof method is to make the tracks inaccessible. There are several ways to create a track which works for minecarts but doesn't allow creature-traversal; the simplest is perhaps building a [[statue]] on the tracks. Other options include adding single-tile holes (minecarts moving at reasonable speed will jump the gap), vertical drops, minecart-triggered doors, small pools of liquid (4/7 water or 2/7 magma), and hostile creatures overlooking the tracks. For safety, both ends of the track should be isolated, making the dangerous center sections completely inaccessible (though maintenance access can be provided by a locked door).

Danger does not always involve living victims: careless route designation can also result in minecarts careening off tracks or colliding with each other. If this occurs, the [[item]]s may be scattered; this can cause even more hauling jobs than the minecart aimed to eliminate. Even <s>better</s> worse, scattered items, especially [[weapon]]s, can injure passing [[dwarf|dwarves]] or other [[creature]]s; in the words of Toady One the Great, "Accidental grapeshotting of the dining room should be possible now."

Of course, the danger of using minecarts means they can also be [[Trap_design#Minecarts|used as weapons]] by imaginative players.

== Advanced usage and automation ==
Minecart-specific effects are implemented via track stops, rollers and [[pressure plate]]s with "track" condition set. Since all three are considered [[building]]s, they can't be built on the same square (however convenient track stop + pressure plate would be) nor a simple ramp, and are removed by {{k|q}} {{k|x}}.

=== More on Track stop ===
Track stops are constructions that allow further automation of minecart systems via adjustable features such as braking by friction and automatic dumping of contents. They can be built from logs, bars and blocks through {{K|b}} {{K|C}} {{K|S}}; friction amount, dumping toggle and dumping direction must be set '''before''' construction, and these settings can be neither changed nor seen thereafter; however, track stops can be linked to [[pressure plate]]s or [[lever]]s to toggle friction and dumping On or Off (trigger state is inverted: switch On = track stop Off).

If a [[stockpile]] is placed on the tile that a track stop is set to dump to, it can act as a [[Exploit#Quantum_stockpiles|quantum stockpile]] and any items dumped from a minecart that match the storage settings of the stockpile will remain there and accumulate. Normally trackstops are built on top of existing track to operate on moving minecarts, but they can also be used without tracks to create [[Exploit#The_Minecart_Stop|automatic quantum stockpiles]] (see also [[#Step-by-step_tutorial|step-by-step tutorial]]). It is not always desirable to collect ALL of certain items into one quantum stockpile, such as when distributing a material to multiple separate industries. You can link your quantum stockpile to various other stockpiles, ensuring that your dwarves will keep them supplied as necessary. Because quantum stockpiles never fill up like regular stockpiles, it may be a good idea to add a switch to turn them off.

Items dumped from a minecart at a track stop (or dumped by any other means) into open space fall through z-levels until they land on a solid surface. Items falling onto a designated [[stockpile]] will automatically be considered part of that stockpile, even if the stockpile is set to disallow those items (they will, however, be automatically moved to a more appropriate stockpile, if available). Items falling on top of a minecart will '''not''' fall "inside" the minecart. Use with caution; dwarves have fragile skulls.{{bug|5945}}

=== Automated propulsion ===
==== Roller ====
{{Main|Roller}}

A '''roller''' is a [[power]]ed [[machine component]] for the automated propulsion of minecarts. They are built over the top of existing tracks with {{K|b|M|r}}, requiring a [[mechanic]], ''(length/4)+1'' [[mechanism]]s and a [[rope]]. Rollers may also be placed directly on ramps to help pull carts up Z levels. Rollers are very useful to maintain a cart's momentum along long routes, to get them to climb Z-levels without dwarfpower involved, and to get them to reach speeds unattainable by guiding dwarves. These devices are variable-length (1-10), variable-direction and variable-speed ([[Minecart#Numbers_behind_the_scene|see below]]), all traits that can be set at construction time; a roller uses two units of power per tile it is long.

Single-tile rollers transfer power in all four cardinal directions, while other rollers generally only transfer power perpendicular to their activity direction. Longer rollers can also transfer power along their activity direction if built in the correct order, although this can be hard to accomplish and is easily broken. Rollers cannot be powered from above.

Rollers have great acceleration and capped speed. Carts going faster than the roller are unaffected. If a cart moves across an active roller in the direction the roller works and moves slower than the roller's specified speed, the cart will be set to the roller's speed. A cart going against a roller's movement direction will be sent back the way it came (once again at the roller's speed), unless it was moving extremely fast: speed increment of 100000 allows to reverse carts from the full "highest" (50000) speed roller to full "highest" speed back, but ramps can accelerate a cart beyond this. {{cite forum|144328/5702453}}
A cart crossing over a roller perpendicular to its current movement direction will gain the roller's amount of speed in the perpendicular direction without directly changing its forward motion. Without an adjacent wall to constrict its movement, this will typically send a cart off the rails on a diagonal path, completely unable to follow any tracks until it collides with a wall or is otherwise brought to rest. However, if the roller is placed over a track turn and pushes ''from'' the direction of that turn's track, the turn affects carts ''after'' the roller, so they will be forced into the turn rather than derailed in a diagonal direction. {{cite forum|144328/5702453}}

{{diagram|spaces=yes|\
tracks: full:
║ ║
═╗═ ═╢═
║ ║

╢ : roller pushing from W to E
}}
If the roller is powered, carts from ''all'' directions (unless too fast) exit S, because speed imparted by the roller forces carts toward E and ''then'' into the turn.
If not powered, carts from W and N exit S, carts from E and S exit W. Carts above derail speed will ignore the turn, of course.

{{diagram|spaces=yes|\
║ ║
═╗═ ═╟═
║ ║

╟ : Roller pushing from E to W
}}
Carts from the E or W: exit W.
Carts from N: derailed diagonally, exit SW.
Carts from S: derailed diagonally, exit NW.

Rollers affects carts on a track - if placed on a floor or ramp without any tracks, they are ignored. Depowered rollers are also ignored, friction is determined by the tiles underneath.

Because of their one-way nature, rollers are unsuitable for most two-way minecart tracks (unless you set gears toggling roller A->B off while toggling A<-B rollers on). However, a minecart set to be ''guided'' is not affected by rollers at all{{cite forum|109460/3286235}} — this allows a one-way track to be used in both directions. In addition, unpowered rollers do not affect minecarts.

Care must be taken in [[glacier]]s and other extremely cold [[biome]]s, since rollers (and the machinery used to power them) will not operate when constructed on natural [[ice]] floors.

==== Impulse ramps ====
Carts can be given momentum without rollers or changing z-level through a phenomenon called "impulse ramps". A track ramp which is connected both to a wall and to a floor will ''always'' accelerate a cart towards the connected floor tile, no matter where the cart enters the tile from. This means carts can be accelerated as though dropping z-levels, even if the cart doesn't actually change z-level at all. If a track ramp faces three directions such as ╩, then two of those directions need to be facing walls for the cart to be accelerated towards the remaining direction.

Example of straight impulse acceleration:

{{diagram|spaces=yes|\
▒▒▒▒▒▒▒▒▒▒ ▒▒▒▒▒▒▒▒▒▒
═▲▲▲▲▲▲▲▲▲▲═ ═╚╚╚╚╚╚╚╚╚╚═
▒ : Wall
═ : Normal track
▲/╚ : N/E Track/Ramp
}}

If a cart enters from the left, it will speed up on every track/ramp and exit to the right going very very fast - more than one tile every step. If it enters from the right then it will bounce back impulsed by the ramp if it's going slow enough.

As another oddity, carts coming from ramps will in some cases "teleport" through most of the next tile. This can be used to send carts up levels with minimal loss of speed. You can just make an upward spiral alternating impulse ramps and regular upward ramps. It takes no power, is quick and cheap to build, requiring only channeling and track carving, and the cart goes up fast, but not so fast that it launches its contents.

Example of an impulse elevator:

{{diagram|spaces=yes|\
z +0 z +1 z +2 z +3
░░░░░ ░░░░░ ░░░░░ ░░░░░
░╔░░░ ░▼╚╗░ ░░▼▼░ ░░░░░
░╝░░░ ░▼░░░ ░░░╔░ ░░░▼░
░▼▼░░ ░░░░░ ░░░╝░ ░╚╗▼░
░░░░░ ░░░░░ ░░░░░ ░░░░░

░ : Wall
╔,╚,╗,╝ : Track/Ramp
▼ : Down Ramp (empty space)
}}

A sort of opposite effect to impulse ramps also exists: ramps lacking the proper "up" and "down" connections are treated as flat track, even if they actually go up or down z-levels. This allows building "anti-impulse" slopes consisting entirely of ramps only connected up, which a minecart can travel up forty levels and more, needing no more than a single push.

=== Controlling traffic ===

==== Switching ====

As constructions or tile features, [[door]]s and other furniture can be built on tracks. A [[door]] or [[floodgate]] can be turned on or off by a [[lever]], effectively controlling the flow of automated minecarts. This may be <s>dangerous</s> [[fun]], however.
{{diagram|spaces=yes|\
->
A ════┤≡════ B
┤ : roller pushing to East
≡ : door
}}
The roller pushes the cart east, but until the "departure condition" is fulfilled, the door remains closed and blocks the path.

[[Bridge]]s can also act as tracks, but only if they're lowered or not retracted. This property can enable levers to turn tracks on and off. However, care should be taken to ensure that such bridges are never operated while a cart is on top of them, as the cart will be flung off the track. It's worth noting that it's often faster, and cheaper, to construct large bridges than long sections of constructed track.

A powered track switch can be constructed by building an "inverted" corner as illustrated below.
{{diagram|spaces=yes|\
B B
║ -> ║
║ ║
════╚═══ ════├════
A C A C
├ : roller pushing to West.
}}

If the cart is pushed East from the stop at 'A' while the roller is activated, it will arrive at 'B'. If the roller is not running, it will arrive at 'C'. The switch works by the roller first reversing the incoming cart's movement and the cart ''then'' following the track corner.

This switch is very reliable, reacts instantly to on/off signals, and carts of any speed can be switched by this design, although very fast carts will require rollers that are several tiles long, up to three. The requirement for power can be inconvenient or impractical. Non-powered solutions may use controlled derailment, or a connecting bridge.
{{diagram|spaces=yes|\
B ╥
║
║
╞════╝ ════╡
A D C
}}
Here the track between A and C is not continuous. The only continuous track is A->B, with a corner (not a T section). Fast moving carts will tend to derail at D and rejoin the track to C. Placing a door at D will prevent the derailment, so the cart continues to B. The door is operated by mechanisms elsewhere (typically, a lever, but some fun can be had with pressure plates).

Since it depends on derailing, this switch requires a very fast cart, faster than what can be achieved with rollers alone. To gain sufficient speed, a cart must be accelerated further, usually by descending several levels or through impulse ramps. The high speed makes the cart much more dangerous and harder to control.

If carts are moving too slowly to derail at the corner, a retractable bridge may be used as a connector between A and C.
{{diagram|spaces=yes|\
B╥
║
║
A╞════bbb════╡C
}}
The bridge must overlap the corner. Bridges behave like a track crossing, allowing carts to pass in a straight line. When retracted, the corner reappears, so the carts will continue to B. Bridges take 100 steps to react to a signal, necessitating rather long "lead times" when switching tracks via bridge.

As mentioned above, special care must be taken to make sure the bridge doesn't change state while the cart is passing over it. Retracting bridges will throw the cart, causing it to stop dead. Raising bridges can even crush the cart.

==== Controlling Speed ====


Minecarts can reach extremely high speeds, especially when descending multiple Z-levels. A minecart will derail at a track corner if its speed exceeds 0.5 t/st (tiles per step), '''unless''' the route in the direction of travel is blocked:

Will derail at > 0.5 t/st:

{{diagram|spaces=yes|\
in ══╗ -> derailing
║
out
}}

Will not derail at > 0.5 t/st:
{{diagram|spaces=yes|\
in ══╗O
║
out

O : wall/column.
}}

This behavior can be used to build a "speed limiter", that will ensure that when a minecart exits it is traveling below derail speed:
{{diagram|spaces=yes|\
░░░░ ░░░░░ ░░░░░
in ═╔═╗░ ░╔S╗░ ░╔S╗░
out ═╬═╝░ out ═╗═╝░ out ═╗═╝░
░╚S╝░ ░╚═╝═ in ░╚S╝░
░░░░░ ░░░░ ║░░░
in
░ : wall
S : Track Stop (High Friction or lower)
}}
If the minecart is traveling below derailment speed, it will not be affected; if above, will be slowed down and checked again. Granted, you could do the same just with track turns, but it may take a lot of turns and time.

Since all the derailings, bounces and ramps can impart a sideway component of speed small enough to start visible drift many tiles away (say, [[Fun|in the middle of a bridge]]), track turns have one more use: forcing the carts to move strictly along the grid directions. Carts passing a turn below derailing speed convert one component of velocity into another, thus eliminating the drift.

=== Loading liquids ===
[[Water]] and [[magma]] can also be loaded into minecarts by submerging them to a depth of at least 6/7 while standing still or moving at speeds of at most 10000. Loading fluids onto minecarts can be difficult because the added friction provided by fluids can stop a cart in a submerged tile. Curiously, filling a minecart with magma does not injure a dwarf ''riding'' it. A minecart will hold enough fluid to increase the depth of a single tile by 2. This amount is listed as 833 units, which weigh 459Γ (water) or 999Γ (magma). An iron or steel cart filled with magma weighs 1313Γ, while an adamantine cart filled with magma weighs 1007Γ. Since you need a minecart above the liquid's level, possible arrangements may include pressure-activated sluices, rollers (with magma-safe chains for magma), pouring from above to "submerge" it briefly on the same level and drain excess away (dig deeper and leave a vaporizer, though if you could have power for rollers, may as well use a pump) and exploits with ramps (not necessarily impulse ramps, "same height" passing dip does it).
The liquids can be dumped by a constructed track stop.

== Quirks ==
This little quirk concerns dwarf-managed minecarts. If a track which was previously open becomes blocked (ex. flipping a switch connected to a floodgate you've built on the track to raise it) and the conditions for departure are met, instead of refusing to ride/guide the minecart or ride/guide it until it reaches the obstacle, the dwarf will pick up the minecart off the tracks and haul it to its scheduled destination on foot. If the distance is long enough and the weight of the cart heavy enough (due to being filled with heavy items such as stones), the dwarf may drop the cart because of fatigue/hunger/thirst before reaching the destination. This will cancel that vehicle setting job and make another dwarf come by and attempt to haul the cart to the nearest appropriate stockpile where another dwarf will pick up the cart and attempt to haul it to its initial stop. If the stockpile is far enough from initial stop, this second dwarf who is attempting to place the minecart on its tracks may also drop the minecart out of fatigue/hunger/thirst creating a loop that will go on until a dwarf with enough endurance manages to place the minecart where it belongs.

In fact, it seems dwarves are more than happy to attempt to carry a minecart from one stop to another even if just waiting until the track is open again would be the more sane option.

Dwarves will also carry a minecart to its next stop if the direction specified is incorrect (or invalid). This can often occur when using the default departure settings and forgetting to set the direction of each condition.

Dwarves can admire buildings while riding mine carts. Dwarves will not fall asleep during a ride (at least not from being drowsy). If riding on a continuous powered track loop, the dwarf will die of dehydration/starvation as they can not jump off to get sustenance{{cite forum|109460/3377228}}. Dwarves riding in submerged minecarts will gain experience in [[swimming]].{{cite forum|129889}}

Tracks block wagon access to trade depots, unless they're on a ramp. [[Bridge]]s can also be used, as they function as tracks but do not block wagons.

== Physics ==


Minecart physics depend greatly on the departure mode set in the route stop conditions.

When set to "Push" or "Ride", minecarts will move according to the regular laws of momentum, gaining speed when going downhill, losing it slowly due to friction when on a flat plane, and more quickly when going uphill. In these modes, minecarts will move in a straight line until they either are brought to a stop by friction or an obstacle, or until they encounter a turn. A minecart will roll straight past "blocked" ends of T-junctions or track ends, they have no power to restrict a cart's movement. The cart's behavior is largely independent of the weight of its contents (including fluids and dwarves): heavily loaded carts gain more momentum when accelerating, but this only plays a role in collisions: a heavy cart gains just as much speed and is as easy to stop as a light one. In either case, dwarves can not push nor ride an unpowered cart up a ramp, bouncing back the direction it came. At best, this is a waste of time; at worst, it will give your cart-pushing dwarf a [[fun|fun surprise]]. To solve this, the player can either use Rollers (see below) or set the cart to be Guided.

The difference between "Push" and "Ride" is whether the dwarf will go along with the cart or not.
{{DFtext|Push}}: the dwarf will give the cart an initial push, not enough to go up a ramp, but enough to go some way along flat track, and the dwarf will remain at the first stop, ready for a new job.
{{DFtext|Ride}}: the dwarf will give the cart the same initial push and then hop aboard the cart riding with it to the next stop.
{{DFtext|Guide}}: minecarts seem to ignore all laws of physics. That is:
*Ignore the weight of any and all items inside. Therefore:
**Move at the speed of the dwarf that is guiding them. It is thus recommended to pick the most [[attribute#Agility|agile]] of your dwarves for cart-guiding tasks.
*Ignore working rollers.
*Will ''not'' collide with other guided carts even when a full frontal collision would be expected.
*Will go up ramps like nobody's business.
This is therefore the recommended method of transport for simple non-powered rail systems, despite it diverting a dwarf from other, potentially more important tasks.

Some samples with behavior:
{{diagram|spaces=yes|\
A <-> B A <-> C A <-> B
B B B
║ ║ ║
A══╝ A══╩══C A══╬╗
You can only go A->B ╚╝
Works when the cart Works
is in Guide mode.
}}
In the second example above, a cart "pushed" from B will go over the junction and roll off into the unknown south.

=== Skipping ===
If a minecart is moving fast enough, it can skip over [[water]] or [[magma]], making splashes of [[mist]] (or [[magma mist]]) as it attempts to move on them horizontally. This horizontal movement is independent of the minecart and its content's [[weight]].

=== Track Jumping ===
If a minecart encounters the end of the track or a T junction with no "exit" in its movement direction, it will simply leave the track and continue on its course in a straight line until it encounters an obstacle, slows to a stop, or encounters another (properly aligned) Track even if the tile at which it joins the new track instantly sends it around a corner.

Tracks that are travelling at high enough velocity will also start "jumping" the track if it hits an un-tracked tile (flying over and ignoring any tracks) until it is ready to land. Carts that land upon tracked tiles re-rail themselves, and clever designers use this feature to jump over curved track sections in one direction or another. (Retracting bridges over untracked tiles can cause jumps or not cause jumps depending upon the status of the bridge.) Minecart speed must be carefully regulated to ensure reliability of jump length.

Carts that approach a downward slope at a high enough velocity will also make a jump, but will not do so if the Checkpoint Effect (below) is exploited through an impulse ramp before the actual downhill as the impulse ramp "tricks" the cart into thinking it has already started going downhill.

=== Corner Ramp Derail ===

Corners on upward ramps can cause diagonal movement, forcing a derail even if the cart has a wall next to it, which will force a stop when it touches a wall that forces dwarves to manually reset the cart.

This is caused by the fact that a cart, after turning the bend in the track halfway through the length of the tile, will still "accelerate down", which is now perpendicular to the movement of the cart, causing acceleration to occur in two directions. (Down corner ramps do not have this problem, as when they pass the halfway point, all perpendicular motion is added to forward motion, and after that curve, all downward acceleration is in the forward direction.)

There are two fixes to this problem. One is to simply not put corners on up ramps. The other is to take advantage of the Checkpoint Effect, below, by making a ramp (possibly including an impulse ramp) one tile in front of the ramp to make it skip through most of the tile before sideways momentum can be built.

=== Checkpoint Effect ===
The checkpoint effect, [http://www.bay12forums.com/smf/index.php?topic=144328.0 explained in depth by Larix], is an odd and highly exploitable feature of ramps where minecarts "teleport" through the next tile of track, ignoring nearly all minecart physics (except that they stop at all walls or other obstacles and not only respect curves, but will take them even when they would otherwise derail) and passing through that tile in just a single tick, and into the next tile at the halfway point.

This effect occurs when a cart leaves a downward ramp for any other direction of tile. This allows, for example, two valid straight ramps directly next to one another with a cart dropped onto one or the other with no momentum to have the cart pick up acceleration going "down" the ramp as normal, but then flying up through the "up" ramp it travels into with no loss of momentum, as though it had come from an impulse ramp. If the two ramps had at least one space of distance between them, and then a cart were dropped in, the cart would instead "rock" back and forth between the two ramps.

This seems to be because ramps have a slightly longer length than regular tiles - 144,000, rather than 100,000 distance. When this "snaps back" after a ramp, it seems to project the cart suddenly further along the track, making it jump a tile ahead even when otherwise moving at relatively low speeds.

This effect would be a "[[bug]]" if it weren't probably deliberately coded, and an "[[exploit]]" if it weren't impossible not to feel its effects. Nevertheless, many designs exploit the checkpoint effect to allow "perpetual motion devices" where a cart stuck between two ramps can climb a ramp with no loss in momentum, creating unpowered perpetual motion devices. This also allows for ramp "elevators" to be constructed even without impulse ramps (although impulse ramps make it more compact, still).

Another useful thing to note about this exploit is that carts traveling at no less than 72,000 or so speed (enough to travel half a ramp tile in a single tick) can travel through every tile in just one tick at no change in velocity as long as the tiles alternate between impulse ramp or actual down ramp and any other tile type. The cart checkpoints through the non-down-ramp tiles, and can pass through the (impulse) down ramp tiles in a single tick, before they can actually start gaining momentum.

=== Falling ===
When falling, a minecart appears to cause no damage upon collision, possibly to allow cart "stacking" across Z-levels.{{cite devlog|2012|04|06}} A dwarf riding in a minecart that is dropped multiple z-levels suffers normal fall damage. Minecarts can fall through up/down stairs.
The cart falling (from a hatch, thus with no horizontal speed) onto a track ramp is accelerated as if starting from the middle of the ramp - i.e. to the same speed, no matter how many Z-levels it was dropped, vertical velocity is negated. {{cite forum|144328/5701211}}

=== Stacking ===
If a minecart lands on top of another minecart, they may form a stack, with the upper cart on the z-level above the lower. Subsequent carts do not form a stack, but rather quantum stockpile in the same space. This behaviour is useful for [[megaprojects]] and [[trap design]] with minecarts as the weaponry. Moderation should still be exercised: carts take longer to fall into a "stacking" tile already occupied by other carts and will spend that time "hanging" in the air above the stack. This can lead to following carts striking them, which can cause all kinds of malfunctions. The extra time is two game steps for every cart already in the stack, which doesn't hurt stacks of ten carts very much but makes stacks of 100+ rather impractical.

These minecarts on the upper level generally need to be struck with another minecart to move out, or have their support removed. The latter option is safest done by shooting it away with another minecart, manual removal of a stack-supporting cart typically causes the next cart from the stack to [[fun|fall on top]] of the hauler.

=== Perfectly Elastic Collisions ===
Minecart collisions are perfectly elastic, meaning that not only do minecarts not take damage, but that two carts that are rolling which have frontal collisions of near-similar speed, and where one cart is no more than twice the mass of the other cart, will result in a billiard-ball-like effect of the lighter cart bouncing off the heavier cart with a proportional speed increase dependent upon the relative momentum behind the heavier cart.

Using this trick with carts already at the 270,000 maximum speed from ramps can result in "supersonic" carts traveling at speeds in the millions (travelling a dozen tiles per tick), but where they are suddenly subject to 10,000 units of "terminal velocity" friction per tick. [http://www.bay12forums.com/smf/index.php?topic=137557.0 Thread with SCIENCE here].

While hypothetically capable of launching a minecart into orbit when used in conjunction with a ramp, no cargo can be contained in the launched cart, as the collisions will force ejections of the cargo. Your "unwilling volunteer" [[goblin]] space pioneers will simply become paste underneath the wheels of an extreme high-speed cart.

=== Numbers behind the scene ===

According to early research by '''expwnent'''{{cite forum|112831/3536975}}:

The minecart has a variable for speed. Speed is measured in tiles/100000 ticks, so a speed of one hundred thousand means one tile per tick. By going down a large number of ramps, a maximum speed of 270,000 can be reached, which presents the limit for most practical applications. Short bursts of (much) higher speeds are possible through carefully planned collisions of high-speed carts {{cite forum|137557/5145499}}.

Every tick the cart accumulates distance units, as well as slows down depending on current tile (speed is reduced by "friction" of the tile). The cart will move to the next tile the tick before accumulating 100000 distance units, (or several tiles in case of great speed), then the leftover distance units are added to the default 100000 distance u. of the next tile. Since most deceleration and acceleration is applied per step, with the notable exception of corners, a cart going at twice the speed of another one can cover about four times the distance in a straight line, but only twice the distance along a winding track with very many corners.

A push will teleport a cart to the beginning of the next tile (NOT the middle!) in one tick with 19990 speed (10 speed is lost due to track friction), while a roller will give a cart the roller's set speed, and it will start to accumulate regular track friction past the middle of the roller tile. Some track features will affect a minecart when it is past the middle of the previous tile: entering a ramp or a hole/drop will happen when the cart has left the middle of the previous tile, and the ramp will gain additional distance unit depending on the leftover units from the previous tile. When a cart leaves a ramp it will emerge after one tick in the middle of the next regular tile, so its entry coordinate is "50000-speed+friction". Rollers also affect the speed of minecart from the middle of the previous tile.

Friction of tiles:
{| class="wikitable"
|-
! Tile
! Friction
! Comment
|-
| Tracks
| 10
|-
| Ground/Floor
| 200
|-
| Unusable ramp
| 10
|-
| Upwards ramp
| 4910 (10+4900)
|-
| Downwards ramp
| -4890 (10-4900)
|-
| Roller
| ±100000 (but capped by the set speed)
|-
| Corner track
| 10
| Speed reduced by 1000 upon leaving the corner tile
|-
| Track stop (highest)
| 50000
|-
| Track stop (high)
| 10000
|-
| Track stop (medium)
| 500
|-
| Track stop (low)
| 50
|-
| Track stop (lowest)
| 10
|-
| Water 1-6
| Additional (WaterLevel - 1) * 100
| rowspan="2" | [[#Skipping|See Skipping]]
|-
| Magma 1-6
| Additional (WaterLevel - 1) * 500
|-
| Empty space
| 0
|}

Water of depth 7/7 provides a friction of about 10000 per step, as does maximum-depth magma. This higher friction may not apply to very slow-moving carts.

Impulse sources:
{| class="wikitable"
|-
! Feature
! Speed
|-
| Push
| 20000
|-
| Roller lowest
| 10000
|-
| Roller low
| 20000
|-
| Roller medium
| 30000
|-
| Roller high
| 40000
|-
| Roller Highest
| 50000
|-
|}

== Non-standard uses ==
Minecarts include some interesting characteristics that have motivated uses beyond hauling. They can be useful for creating fully-automated [[exploit|quantum stockpiles]] and [[garbage disposal]]s. Storing perishable goods (meat, meals, etc.) inside a minecart appears to guard against rot and vermin.
Minecarts can be [[Trap_design#Minecarts|used as weapons]], or as (hopefully non-fatal) triggers to restart stalled [[healthcare]]. They can also be used to time/control game events, either using a basic [[repeater]] or much more advanced [[minecart logic]].
Minecarts trigger [[pressure plate]]s, which means a trap can be designed to trigger when a thief attempts to steal a minecart.
A pressure plate can be used as automatic and more precise custom "launch when full enough" system - as long as weight of your minecarts stays the same. You cannot build a hatch or roller on the same tile, so launch by bumping with another cart. {{cite forum|15096/4580050}}
Dwarves riding minecarts can attack enemies within reach (which goes back to dev log). This applies to shooting, and they actually can hit targets while riding by.{{cite forum|109460/5266119}} Whether a minecart protects the rider and how it interacts with dodging is not known yet. Minecart riders can also [[Swimming#Minecart_training|train swimming]] and [[Megaprojects#Surveillance_Track|detect ambushers]].

== Adventure mode ==
In addition to being used for hauling, minecarts can also be ridden in [[adventure mode]]. (Adapted from forum thread {{cite forum|122903/4258212}})

# If the minecart is in your inventory, drop it. If it is already on the ground, proceed to step 2.
# Press {{k|u}} when you are 1 tile away from the minecart (or standing on the same tile as the minecart).
# You will be presented with the following options:
[[File:minecart adventure mode menu.png|left]]
{{clear}}
* If you {{DFtext|Push}} the minecart, it will move a few tiles in the direction you chose. Physics comes into play here, so it will gain/lose speed depending on the usual factors.
* If you {{DFtext|Ride}} the minecart, you will hop into the minecart, even if you were a tile away, and it will move in the chosen direction with you in it. It will gain/lose speed depending on the usual factors. Whilst the minecart is in motion, you should press {{k|.}} to skip your turn; if you attempt to move whilst the minecart is still in motion, the laws of physics come into play, and you will take [[wound|damage]]. Alternatively, you can push the minecart whilst it's still in motion (although it's unclear how one can bend [[physics]] so as to push a moving minecart whilst inside the minecart). If you push it in the same direction you are already travelling in, you will greatly increase the minecart's velocity. You can also push it in different directions, and this will cause it to gradually change direction-the amount of pushes this requires depends on the minecart's velocity. Once the minecart has stopped moving, you may move out of it safely, or you may want to give it another push. Note that if you push a minecart right after having ridden it (still on the same tile as the minecart), it will act as though you chose to ''ride'' it.

If you want to test this out without creating an adventurer, the [[object testing arena]] allows you to spawn minecarts ({{k|k}}-{{k|c}}-{{k|n}})

== Forging and Melting ==
* Metal minecarts cost '''two''' [[metal]] bars to forge, or '''six''' [[adamantine]] wafers.
* When a non-adamantine metal minecart is melted down, it will return '''1.8''' metal bars, for an '''efficiency of 90%'''.
* When an adamantine minecart is melted down, it will produce '''1.8''' wafers, for an '''efficiency of 30%'''.

== See also ==
* [http://www.bay12forums.com/smf/index.php?topic=109460.0 The "How Does Minecart" Thread] by '''Girlinhat''' et al.
* [http://www.bay12forums.com/smf/index.php?topic=112831.0 SCIENCE: Quantifying minecart physics] by '''Snaake''' et al.
* [http://www.bay12forums.com/smf/index.php?topic=129676.0 How to build a Multi-cart Ore to Magma Minecart Project without needing power] by '''WanderingKid'''.
* [http://www.bay12forums.com/smf/index.php?topic=144328.0 My very own Minecart Education Thread. Ten Lessons, now complete.] by '''Larix'''.

== Bugs ==
*A dwarf will drop her [[child|baby]], if she has one, when boarding a minecart set to be ridden.
*Dwarves have no concept of traffic safety and will walk into busy minecart lines to retrieve objects, often with deadly consequences. This is especially problematic in [[Swimming#Minecart_training|clever applications]] depending on dwarves riding the carts very frequently, because they have a bad habit of dumping their worn clothes on the tracks after a minecart ride. Adding an automatically-operated [[hatch cover]] at the end of such a ride can help prevent [[unfortunate accident]]s.
*Dwarves cannot guide a minecart through an unlocked door unless another dwarf opens the door.{{bug|6056}}
*It is possible for a creature and minecart moving towards each other to pass without collision if they exchange tiles in the same tick.
*After a minecart ride, a dwarf will sometimes haul the minecart to a storage stockpile, leaving another dwarf to haul the vehicle back to the route.
*Minecarts falling onto a floor injure creatures in the tile below the floor.{{bug|6068}}
*A minecart's initial velocity is not affected by weight, when pushed or launched from rollers.{{bug|6296}}
*Removing a stop that has a vehicle waiting on it may cause the game to crash.{{bug|5980}}

{{Category|Fortress mode}}
{{Category|Interface}}

[[ru:Minecart]]

Syndrome

2015-06-15T20:10:39Z

NW Kohaku: Made counter syndromes a separate section so it could be linked to directly for explanation purposes.

{{Quality|Masterwork|13:02, 6 April 2015 (UTC)}}
{{av}}

A '''syndrome''' is a disease or effect that a poor, hapless creature might get through encountering certain creatures, extracts, supernatural weather, or vindictive modders. They generally cause unpleasant and frequently fatal [[symptoms]] over a short to long period of time, but some will clear up over time or with the assistance of a [[doctor]]. A [[Health care|Hospital]] is required to diagnose and potentially treat the syndrome. [[File:Snakebite.png|200px|thumb|right|An example of a syndrome in effect. This hippo did not ultimately survive the encounter despite one bite being the only injury sustained.]]

==List of syndromes==
{| {{prettytable}}
|- bgcolor="#dddddd"
! Syndrome
! Venom
! Acquired
! Short-term Symptoms
! Long-term Symptoms
! Chronic Symptoms
|-
| Adder bite
| adder venom (injected)
| Being bitten by an [[adder]], [[giant adder]] or [[adder man]]
| Strong pain
| Swelling Blisters Nausea
|
|-
| Bark scorpion sting
| bark scorpion venom (injected)
| Being stung by a [[bark scorpion]], [[giant bark scorpion]] or [[bark scorpion man]]
| Strong pain
| none
| none
|-
| Black mamba bite
| black mamba venom (injected)
| Being bitten by a [[black mamba]], [[giant black mamba]] or [[black mamba man]]
| Dizziness Drowsiness Strong pain Fever Unconsciousness Complete paralysis1
|
|
|-
| Blob blisters
| cave blob fluid (contact or ingested)
| Touching a [[cave blob]]
| Mild pain Mild blisters
| None
| None
|-
| Brown recluse spider bite
| brown recluse spider venom (injected)
| Being bitten by a [[brown recluse spider]], [[giant brown recluse spider]] or [[brown recluse spider man]]
| Nausea Fever Pain 
| Severe localized necrosis
|
|-
| Bumblebee sting
| bumblebee venom (injected)
| Being stung by a [[bumblebee]] worker
| Pain Strong swelling
|
|
|-
| Bushmaster bite
| bushmaster venom (injected)
| Being bitten by a [[bushmaster]], [[giant bushmaster]] or [[bushmaster man]]
| Strong pain Mild bleeding Dizziness Nausea Unconsciousness Complete paralysis1
|
|
|-
| Cave floater sickness
| cave floater gas (inhaled or ingested)
| Expelled from [[cave floater]]
| Mild nausea
| Fever Strong drowsiness (delayed) Strong dizziness (delayed)
| None
|-
| Cave spider bite
| cave spider venom (injected)
| Being bitten by a [[cave spider]]
| None
| None
| Very mild dizziness
|-
| Copperhead snake bite
| copperhead snake venom (injected)
| Being bitten by a [[copperhead snake]], [[giant copperhead snake]] or [[copperhead snake man]]
| Pain Swelling Nausea
|
|
|-
| Giant cave spider bite
| giant cave spider venom (injected)
| Being bitten by a [[giant cave spider]]
| Size-dependant paralysis.
| Death by asphyxiation, in small targets. Large targets are generally unhindered.
| None, not that it really matters.
|-
| Gila monster bite
| gila monster venom (injected)
| Being bitten by a [[gila monster]], [[giant gila monster]] or [[gila monster man]]
| Pain Mild swelling
|
|
|-
| Gnomeblight
| [[gnomeblight]] (contact, inhaled, injected, or ingested)
| Unknown. Affects gnomes only
| None
| Severe systemic necrosis2
| None
|-
| Giant desert scorpion sting
| giant desert scorpion venom (injected)
| Being stung by a [[giant desert scorpion]]
| Necrosis of the brain and nervous system
| '''Certain death'''
| None, not that is really matters.
|-
| Helmet snake bite
| helmet snake venom (injected)
| Being bitten by a [[helmet snake]]
| Minor bleeding
| Fever Nausea Dizziness Localized swelling Localized oozing Localized bruising Strong pain Intense localized necrosis Possible loss of limb
| None
|-
| Honey bee sting
| honey bee venom (injected)
| Being stung by a [[honey bee]] worker
| Pain Strong swelling
|
|
|-
| Iron man cough
| iron man gas (inhaled)
| Expelled by [[iron man]]
| Coughing blood
| None
| None
|-
| King cobra bite
| king cobra venom (injected)
| Being bitten by a [[king cobra]]
| Complete paralysis1 Pain, dizziness, drowsiness
| None
| None
|-
| Phantom spider bite
| phantom spider venom (injected)
| Being bitten by a [[phantom spider]]
| None
| Numbness and mild dizziness
| None
|-
| Platypus sting
| platypus venom (injected)
| Being kicked by a [[platypus]], [[giant platypus]] or [[platypus man]]
| Pain and swelling
| Extreme pain, swelling possibly to the point of necrosis
| None
|-
| Rattlesnake bite
| rattlesnake venom (injected)
| Being bitten by a [[rattlesnake]], [[giant rattlesnake]] or [[rattlesnake man]]
| Pain, nausea, blisters, swelling, bruising
| Severe localized necrosis
| None
|-
| Serpent man bite
| serpent man venom (injected)
| Being bitten by a [[serpent man]]
| Complete paralysis1
| None
| None
|-
| [evil rain] sickness3
|rowspan=5| random
| Being caught outside in freakish weather in an evil biome
|rowspan=5| random
|rowspan=5| random
|rowspan=5| random
|-
| [evil cloud] sickness4
| Being caught in a creeping cloud in an evil biome
|-
| beast sickness5
| Encounters with [[forgotten beast]]s
|-
| titan sickness5
| Encounters with [[titan]]s
|-
| demon sickness5
| Encounters with [[demon]]s
|}
:1. For small creatures such as humans and dwarves, paralysis tends to result in suffocation.
:2. Necrosis of the brain will eventually result in death once the brain rots away completely.
:3. Evil rain typically only causes minor symptoms such as blisters, bruising, coughing blood, dizziness, fever, nausea, oozing, and pain.
:4. Evil clouds either cause major symptoms (as with beast/titan/demon sicknesses) or permanently transform creatures into [[Undead|zombie-like]] forms.
:5. [[Titan]]s, [[forgotten beast]]s, and [[demon]]s have a chance to have a randomized syndrome. These range from pointless (mild blisters from inhaling boiling blood) to instantly fatal (severe necrosis from a contact poison attached to a breath weapon/creature made of blood).

==The anatomy of a syndrome==
Mechanically, syndromes are bundles of tokens attached to a material - they're confined to creature materials in vanilla DF, but it's a simple matter to add them to inorganic materials. When the material is injected, touched, inhaled, or ingested (depending on the syndrome), the creature suffers the predations of a nasty disease or poison. Here's an example syndrome, taken from the Giant Cave Spider raws.

If you are having troubles getting the syndromes to work (i.e., in combat reports, getting "'''supersnake''' n/a splatters~etc"), then simply throw the venom template into the actual creature's raw, which is what the LOCAL_CREATURE_MAT actually calls on; the venom being in the same file.

[USE_MATERIAL_TEMPLATE:POISON:CREATURE_EXTRACT_TEMPLATE]
[STATE_NAME:ALL_SOLID:frozen giant cave spider venom]
[STATE_ADJ:ALL_SOLID:frozen giant cave spider venom]
[STATE_NAME:LIQUID:giant cave spider venom]
[STATE_ADJ:LIQUID:giant cave spider venom]
[STATE_NAME:GAS:boiling giant cave spider venom]
[STATE_ADJ:GAS:boiling giant cave spider venom]
[PREFIX:NONE]
[ENTERS_BLOOD]
[SYNDROME]
[SYN_NAME:giant cave spider bite]
[SYN_AFFECTED_CLASS:GENERAL_POISON]
[SYN_IMMUNE_CREATURE:SPIDER_CAVE:ALL]
[SYN_INJECTED]
[CE_PARALYSIS:SEV:100:PROB:100:RESISTABLE:SIZE_DILUTES:START:5:PEAK:10:END:20]

The first line, USE_MATERIAL_TEMPLATE, is creating a new material, called POISON, using the CREATURE_EXTRACT_TEMPLATE as the basis. After this, the STATE_NAME and STATE_ADJ tokens are used to define the names and adjectives assigned to different states of the material - GAS, LIQUID and ALL_SOLID, in this case, though ALL is also a valid token. At this stage, you can use any material tags like MAT_FIXED_TEMP or similar to set further material properties, though this usually isn't necessary.

ENTERS_BLOOD
This tag determines whether a poison enters the blood or not. If it is not included, the poison will splatter (if liquid) or flow (if gas) over the affected body part instead when injected. If you're using a contact poison, leave this out. Necessary for injected poisons.
SYNDROME
This tag ends the material details and begins the definition of the actual syndrome.
SYN_NAME
This one is self-explanatory - the name of the syndrome as it will appear in-game.
SYN_AFFECTED_CLASS
This token defines what CREATURE_CLASS will be affected by the syndrome. Most creatures are classed under GENERAL_POISON. Multiple tokens can be used in a single syndrome.
SYN_IMMUNE_CLASS
As above, but makes class immune.
SYN_IMMUNE_CREATURE
This token defines which creatures CANNOT be affected by the syndrome - useful for addressing specific instances within a population, such as a specific caste or an individual creature that falls under GENERAL_POISON. Syntax is [SYN_IMMUNE_CREATURE:creature:caste]. ALL can be used for the caste.
SYN_AFFECTED_CREATURE
As above, but makes creature or caste susceptible.
SYN_CLASS
This tag sets a class for the syndrome that can be used in [[Interaction token|interactions.]]

SYN_INJECTED, SYN_CONTACT, SYN_INHALED, SYN_INGESTED
This token determines the method of infection - injected syndromes must be injected via a creature attack, while contact syndromes result from any contamination of a creature by material splatter (such as blood), inhaled syndromes must be inhaled in gaseous form (such as from boiling or a creature breath attack), and ingestion syndromes must be eaten or drunk. Any combination of these tags can be used. A fun variation on the usual creature injection routine is to create a material with a SYN_CONTACT syndrome and have a creature use it for blood - this tends to end poorly for any predator that chooses to attack them.

[SPECIALATTACK_INJECT_EXTRACT:LOCAL_CREATURE_MAT:VENOM:LIQUID:100:100]
This is one method for getting a poison into a creature. If [ENTERS_BLOOD] is applied, it will be injected into the bloodstream. Otherwise, it will just splatter over the area. Put this on a creature attack. Substance type (gas, liquid, solid) does not appear to have an effect. The numbers on the end are minimum and maximum.

CE_X, or creature effect tokens, are the real meat and bones of your syndrome. They're detailed below.

==Creature effect tokens==
Each and every syndrome has a number of creature effect tokens, represented by CE_X - these lovely little beauties determine exactly how the poor creature suffering from the syndrome is affected. An example CE token is as follows:

[CE_NECROSIS:SEV:100:PROB:100:LOCALIZED:VASCULAR_ONLY:RESISTABLE:START:50:PEAK:1000:END:2000]

In this example, we have an effect that will always cause severe necrosis in whichever bodypart it touches, so long as that bodypart is vascular and that the creature is not able to resist it in some manner. The effect begins shortly after the syndrome is contracted, peaks 1000 [[time|time units]] afterwards, and finally ceases another 1000 time units later.

As a general rule of thumb, so long as CE_X starts the string and START/(PEAK/END) end it, the order of the intervening tokens isn't important. PEAK and END aren't required.

*CE_X
The effect type. This can be a number of different tokens, as detailed in the table below this list.
*SEV:X
The severity of the effect. Higher values appear to be worse, with SEV:1000 CE_NECROSIS causing a part to near-instantly become rotten.
*PROB:X
The probability of the effect actually manifesting in the victim, as a percentage. 100 means always, 1 means a 1 in 100 chance.
*LOCALIZED (Overwrites BP tokens)
This tag causes an effect to ignore all BP tokens and then forces the game to attempt to apply the effect to the limb that came into contact with the contagion - i.e. the part that was bitten by the creature injecting the syndrome material, or the one that was splattered by a contact contagion. If an effect can not be applied to the contacted limb (such as IMPAIR_FUNCTION on a non-organ) then this token makes the syndrome have no effect. This token also makes inhaled syndromes have no effect.
*BP:BODY_PART:TISSUE (Overwritten by LOCALIZED)
Specifies which body parts and tissues are to be affected by the syndrome. BODY_PART can be BY_CATEGORY:x to target body parts with a matching [CATEGORY:x] [[body token]] (or ALL to affect everything), BY_TYPE:x to target body parts having a particular type (UPPERBODY, LOWERBODY, HEAD, GRASP, or STANCE), or BY_TOKEN:x to target individual body parts by their ID (as specified in the [BP] token). For example, if you wanted to target the lungs of a creature, you would use BP:BY_CATEGORY:LUNG:ALL. The syndrome would act on all bodyparts within the creature with the CATEGORY tag LUNG and affect all tissue layers. For another example, say you wanted to cause the skin to rot off a creature - you could use BP:BY_CATEGORY:ALL:SKIN, targeting the SKIN tissue on all bodyparts. Multiple targets can be given in one syndrome by placing the BP tokens end to end. This is one of the most powerful and useful aspects of the syndrome system, as it allows you to selectively target bodyparts relevant to the contagion, like lungs for coal dust inhalation, or the eyes for exposure to an acid gas. Not everything takes a target!
*VASCULAR_ONLY (Optional)
This syndrome only affects tissue layers with the VASCULAR token.
*MUSCULAR_ONLY (Optional)
This syndrome only affects tissue layers with the MUSCULAR token. Are you seeing a trend here?
*SIZE_DILUTES (Optional)
This token presumably causes the effects of the syndrome to scale with the size of the creature compared to the size of the dose of contagion they received, but has yet to be extensively tested.
*SIZE_DELAYS (Optional)
As above, this token has yet to be tested but presumably delays the onset of a syndrome according to the size of the victim.

The details of this table are still being thrashed out by modders, so if you have anything to add, please don't hesitate to hit the edit button!

Non-targeted syndromes will ignore any BP tokens and LOCALIZED tokens.
{| {{prettytable}}
|- bgcolor="Bisque"
! Token
! Accepts Target
! Description
|-
| CE_BLEEDING
| Yes
| Causes the targeted bodypart to start bleeding, with heavy enough bleeding resulting in the death of the sufferer. Some conditions seem to cause bleeding to be fatal no matter how weak.
|-
| CE_BLISTERS
| Yes
| Covers the targeted bodypart with blisters.
|-
| CE_BRUISING
| Yes
| Causes the targeted bodypart to undergo bruising.
|-
| CE_IMPAIR_FUNCTION
| Yes
| An organ afflicted with this CE is rendered inoperable - for example, if both lungs are impaired the creature can't breathe and will suffocate. This token only affects organs, not limbs. Note that this effect is currently bugged, and will not "turn off" until the creature receives a wound to cause its body parts to update.
|-
| CE_NECROSIS
| Yes
| Causes the targeted bodypart to rot, with associated tissue damage and miasma. Badly necrotic limbs will require amputation and heavy rot will eventually result in bleeding. Necrosis has some strange behavior involving bleeding to death that isn't fully understood; a 100% necrotic creature can survive fine with no non-yellow bodyparts but will die of bleeding as soon as they end a round of combat, even if they never take a hit. Because of this, fairly useless unless targeting the lungs or eyes.
|-
| CE_NUMBNESS
| Yes
| Causes numbness in the affected body part, blocking pain. Extreme numbness may lead to sensory nerve damage.
|-
| CE_OOZING
| Yes
| Causes pus to ooze from the afflicted bodypart.
|-
| CE_PAIN
| Yes
| Afflicts the targeted bodypart with intense pain.
|-
| CE_PARALYSIS
| No
| Causes paralysis. Paralysis is complete paralysis and will cause suffocation in smaller creatures.
|-
| CE_SWELLING
| Yes
| Causes the targeted bodypart to swell up. Extreme swelling may lead to necrosis.
|-
| CE_COUGH_BLOOD
| No
| This effect results in the sufferer periodically coughing blood, which stains the tile they're on and requires cleanup. It doesn't appear to be lethal, but may cause minor bleeding damage.
|-
| CE_DIZZINESS
| No
| Inflicts the Dizziness condition, occasional fainting and a general slowdown in movement and work speed.
|-
| CE_DROWSINESS
| No
| Causes the Drowsiness condition.
|-
| CE_FEVER
| No
| Causes the Fever condition.
|-
| CE_NAUSEA
| No
| Causes the Nausea condition, and heavy vomiting. Can eventually lead to dehydration and death.
|-
| CE_UNCONSCIOUSNESS
| No
| Renders unconscious.
|-
| CE_VOMIT_BLOOD
| No
| This effect results in the sufferer periodically vomiting blood, which stains the tile they're on and requires cleanup. It doesn't appear to be lethal, but may cause minor bleeding damage.
|}

===Special Effects===
Several special syndrome effects take different arguments than the above. These are used for generated interactions in unmodded games, but may be used as well for any substance or custom interaction.

{| {{prettytable}}
|- bgcolor="Bisque"
! Token
! Accepts Target
! Arguments
! Description
|-
| CE_ADD_TAG
| No
| tags
| Adds a tag to the affected creature. Many arguments can be used sequentially within one syndrome token. See the [[Interaction token]] '''IT_REQUIRES''' for valid tags.
|-
| CE_REMOVE_TAG
| No
| tags
| Removes a tag from a creature. Supported arguments are the same as CE_ADD_TAG.
|-
| CE_DISPLAY_TILE
| No
| TILE:[[DF2012:Tilesets|tile number]]:[[DF2012:Color#Modding color|colour]]
| The creature displays the specified tile and colour instead of its normal one.
|-
| CE_DISPLAY_NAME
| No
| NAME:singular:plural:adjective
| Attaches a specified name to the creature's normal name.
|-
| CE_FLASH_TILE
| No
| TILE:tile number:colour:FREQUENCY:ticks default tile:ticks syndrome tile
| The creature flashes between its normal tile and the one specified here.
|-
| CE_PHYS_ATT_CHANGE
| No
| [[Attribute]]:percentage:fixed boost(?)
| Alters the physical [[attribute]]s of a creature.
|-
| CE_MENT_ATT_CHANGE
| No
| [[Attribute]]:percentage:fixed boost(?)
| Alters the mental [[attribute]]s of a creature.
|-
| CE_BODY_APPEARANCE_MODIFIER
| No
| APPEARANCE_MODIFIER:HEIGHT/LENGTH/BROADNESS:percentage(?)
| Alters the size of the creature.
|-
| CE_BP_APPEARANCE_MODIFIER
| Yes
| body part:APPEARANCE_MODIFIER:attribute:number]
| Alters the characteristics (height, width etc.) of a body part.
|-
| CE_MATERIAL_FORCE_MULTIPLIER
| No
| MAT_MULT:[[material token|material]]:A:B
| Makes creature affected by materials more or less by a factor of A/B. If A is 3 and B is 2, the creature will be 1.5x weaker to the defined material (can be NONE:NONE for all); if 2:3, the creature will be 1.5 times stronger.
|-
| CE_BODY_MAT_INTERACTION
| No
|
| Causes one of the creature's materials to trigger an interaction, generally when ingested. Several additional tokens may be specified after this:
* CE:INTERACTION:interaction_id
* CE:SYNDROME_TAG:syndrome_trigger_type (SYN_INGESTED, SYN_INJECTED, etc.)
|-
| CE_SPEED_CHANGE
| No
| speed modifier:number
| Changes the speed of a creature.
Speed modifier contains one or both:
* SPEED_PERC:percentage (this modifies a creature's in-game speed, so higher numbers are faster)
* SPEED_ADD:number (this modifies a creature's [SPEED:XX] token, so higher numbers are slower. Negative numbers are accepted though will only reduce a creature's speed to zero)
The minimum and maximum speeds able to be created by CE_SPEED_CHANGE are 99 and 10,000 respectively.
|-
| CE_CAN_DO_INTERACTION
| No
|
| Makes the creature able to perform an interaction. See [[Interaction token]]. To specify the interaction, use the argument:
* CDI:INTERACTION:interaction name
|-
| CE_BODY_TRANSFORMATION
| No
| PROB:percentage:START:time:END:time
| Transforms into another creature. PROB and END arguments optional. The target creature is specified with:
* CE:CREATURE:CREATURE_ID:CASTE_ID (ex. CE:CREATURE:DWARF:FEMALE) 
Note that any wounds the creature has suffered will instantly heal upon transforming, both into and out of the target form. [[Undead]] limbs of a creature with this token will grow into a full instance of that creature.
|-
| CE_SKILL_ROLL_ADJUST
| No
| PERC:percentage:PERC_ON:percentage
| Alters the skill level of a creature. The argument PERC specifies a percentage of the creature's current skill, and PERC_ON the probability of the effect being applied on a particular roll.
|-
| CE_SENSE_CREATURE_CLASS
| No
| CLASS:creature class:tile:color
| Allows creature to see other creatures with given class through walls. Vampires, for example, have CLASS:GENERAL_POISON:15:4:0:1.
|}

'''All''' creature effect tokens take START, END and PROB numbers, and can be followed by [CE:PERIODIC] and/or [CE:COUNTER_TRIGGER] to restrict when they actually take effect.
* PERIODIC:period_type:min_value:max_value
* {{text anchor|COUNTER_TRIGGER}}:counter_name:min_value:max_value:REQUIRED

Currently, the only valid period type is MOON_PHASE.

===Counter Triggers===
Valid counter values are below:

{| {{prettytable}}
|- bgcolor="Bisque"
! Counter
! Description
|-
| ALCOHOLIC
| How long it's been (in [[time]] units) since the creature last had a drink of alcohol. Only present on creatures who need alcohol to get through the working day.
* 100800 (3 months) = and is starting to work slowly due to its scarcity
* 201600 (6 months) = and really wants a drink
* 302400 (9 months) = and has gone without a drink for far, far too long
* 403200 (1 year) = and can't even remember the last time he/she had some
|-
| MOUNTAIN
| How much the creature minds being outdoors. Low values are known to decrease the severity of certain unhappy [[thought]]s.
* 0 = likes working outdoors and grumbles only mildly at inclement weather.
* 1 = does not mind being outdoors, at least for a time.
* 2 = (no message)
|-
| TIME_SINCE_BREAK
| How long it's been (in [[time]] units) since the creature last went on [[break]]. Creatures generally go at least a year (100800 time units) between breaks unless the [[economy]] is active (which never happens).
|-
| ON_BREAK
| How long (in [[time]] units) the creature has been on break. Once it reaches 15000 (about 12.5 days), the creature should get back to work.
|-
| CAVE_ADAPT
| How cave-adapted the creature is. Increases by 1 for every [[time]] unit spent underground, to a maximum of 800000.
* 403200 (1 year) = going outside causes irritation
* 604800 (1.5 years) = going outside causes nausea
|-
| PARTIED_OUT
| How long before the creature will decide to attend another party. Starts at 3+ months and counts down to zero.
|-
| MILK_COUNTER
| How long before the creature can be milked again. Starts at the creature's MILK frequency and counts down to zero.
|-
| EGG_SPENT
| How long before the creature can lay more eggs. Starts at 3 months and counts down to zero.
|-
| GROUNDED_ANIMAL_ANGER
| How angry (and likely to attack) an animal is from being over-crowded. Increases when over-crowded and otherwise counts down to zero.
|-
| TIME_SINCE_SUCKED_BLOOD
| How long it's been (in [[time]] units) since the creature last sucked somebody's blood.
|-
| DRINKING_BLOOD
| How much longer the creature will be drinking somebody's blood. Starts at 2.4 days and counts down to zero.
|}

==Inorganic syndromes and you!==
It's perfectly possible - and quite simple - to add a nasty syndrome to a type of rock or metal - you simply add the syndrome tokens to the material definition in the same manner that you would add them to a creature material definition. The only catch is that since your hapless dwarves will only normally encounter the material in metal, gem or boulder form, a bit of creativity must be used to actually get them inside your citizens - that is, you need to make them 'explosively boil' as soon as they're mined or produced. This has the sad side effect of destroying the actual item - sorry, no highly radioactive uranium this release.

The easiest way to accomplish this is to assign the material a low boiling point, usually just under room temperature, and make sure its temperature is fixed to a point above it.
[MAT_FIXED_TEMP:9001]
[BOILING_POINT:9000]
Now, as soon as this substance hits the open air - by being mined, smelted or reaction-produced at a custom workshop - it will EXPLOSIVELY BOIL, flooding a small area with delicious syndrome-rich gas. Creatures who inhale the gas will be immediately hit with the syndrome you thoughtfully attached to the material definition earlier!

There are a number of other tokens you can use to control the colour and naming conventions of your syndrome material, referred to as MATERIAL tokens.

{{Category|Modding}}
{{Category|Creature attributes}}
[[ru:DF2012:Syndrome]]

Giant tortoise

2015-06-12T23:22:07Z

NW Kohaku:

{{Quality|Exceptional|17:56, 9 June 2013 (UTC)}}
{{creaturelookup/0
|shell=1
|bone=19
|meat=15
|scale=1
|skull=1
|brain=1
|kidney=2
|spleen=1
|sweetbread=1
|tripe=1
|liver=1
|intestine=1
|heart=1
|lung=2
|fat=13
|vary=[[Giant tortoise]] - [[Giant tortoise man]] - [[Gigantic tortoise]]
|wiki=yes|contrib=no}}
{{av}}
{{creaturedesc}}
'''Giant tortoises''' are the "mundane" version of [[gigantic tortoise]]s. They appear in groups of 5-10 in tropical areas, and can live up to 200 years. When fully grown, male giant tortoises are roughly as large as a common [[donkey]], and twice the size of female giant tortoises. All giant tortoises are equally slow, moving at less than a third of the default [[speed]].

Tortoises are also extremely benign, and will nearly always react to threats by retracting into their shells, rather than fighting. Because of this, they nearly never frighten worker dwarves, and since they do not move when in their shell, you can freely build a cage trap directly underneath a tortoise in their shell.

Giant tortoises can be [[tame]]d and kept as low-value [[pet]]s, farmed for [[egg]]s, or bred for a [[meat industry]]. With 5-10 eggs in a clutch, they are poor for egg industry, but for the meat industry, they are born in larger numbers than most larger creatures. They produce a moderate amount of meat without tying up your [[pasture]]land, and their [[shell]]s can prove valuable for fulfilling [[strange mood]] requests. Note, however, that giant tortoises require five years to reach full adult size.

Interestingly, only [[male]]s seem to produce nose cartilage when butchered (which currently has no real use, and there are far better ways to determine gender).

[[Image:Giant-Tortoise-Santa-Cruz.jpg|thumb|center|400px|[[preference|Admired]] for their ''great size''.]]
{{gamedata}}
{{creatures}}

Gigantic tortoise

2015-06-12T23:18:20Z

NW Kohaku:

{{Quality|Fine|18:40, 19 August 2012 (UTC)}}
{{Creaturelookup/0
|vary=[[Giant tortoise]] - [[Giant tortoise man]] - [[Gigantic tortoise]]
|bone=23-35
|meat=27-59
|fat=13-19
|lung=2-4
|heart=1
|intestine=3-7
|liver=1-2
|tripe=1-2
|sweetbread=1
|spleen=1
|kidney=2
|brain=1-2
|skull=1
|shell=6-12
|skin=scale
|contrib=no
|wiki=no
}}
{{av}}
{{creaturedesc}}
'''Gigantic tortoises''' are the monstrous version of [[giant tortoise]]s. Along with [[gigantic panda]]s and [[gigantic squid]]s, they receive the "gigantic" title instead of "giant", since there is a normal version of those creatures that is already referred to as "giant".

Due to the fact that tortoises are not only benign, they also react first and foremost by retracting into their shell, if a herd of gigantic tortoises walk onto your map, it is possible to actually build cage traps directly underneath a tortoise that is in its shell to capture it without worry.

With the males half the size of an elephant at full size (5 years), these creature provide enough food products to feed a decent-sized fortress for a year. Also, due to the fact that they are born in clutches of 5-10 at a time, a breeding pair and offspring of gigantic tortoises is fully capable of supplying all the food a fortress will ever need. For moods, they also provide shells.

{{gamedata}}
{{Creatures}}

Grape

2015-06-09T02:26:55Z

NW Kohaku: Added substance to the page

{{Quality|Superior|13:06, 18 May 2015 (UTC)}}
{{plantlookup|uses=
* [[Food]]
}}
{{av}}{{buggy}}

Grapes are a type of garden [[crop]] most known for being the "proper" source of wine. Grape wine is merely called "wine", as opposed to other fruit wines.

Oddly, in spite of encompassing almost all preferred varieties of wine, dwarves (and humans, for that matter,) have no particular desire for wine over other, more notably wretched forms of wine like [[turnip]] wine.

==Bugs==
Grapes cannot currently be farmed correctly. Dwarves harvest leaves, and not the grapes, themselves, and cannot produce any seeds from the leaves, resulting in a farm that cannot be sustained.

{{Translation
| dwarven = mashus
| elvish = pocace
| goblin = tat
| human = sothro
}}

{{gamedata}}
{{Plants}}

Crop

2015-06-09T02:23:52Z

NW Kohaku:

{{Quality|Exceptional|23:05, 8 April 2015 (UTC)}}
{{av}}{{buggy}}
:''(This article is about plants. If you want information about trees, see [[Tree]].)''

{{catbox|DF2014:Plants}}'''Crops''' (or more accurately '''plants''') can either be [[farming|farmed]], traded for, or acquired by plant gathering. Farming happens at farm plots. There are two types of crops: above ground and subterranean. The [[seed]]s of subterranean crops may be brought from the starting embark screen or, with some small luck, purchased from dwarven caravans. Above ground crops and [[seed]]s may be purchased from human or elven caravans or gathered by dwarves with the [[plant gathering]] labor enabled. Seeds may also be collected by processing the plants or eating them (but not by cooking!). There is a limit of 200 seeds per type (adjustable in [[d_init.txt]]), after which no additional seeds will be produced.

A few of the plants listed below are not strictly crops, as they have no seeds and can't be planted (see note "4", below.)

Most plants can be brewed into [[alcohol]]s, each plant type producing a different variation, and dwarves do prefer some variety in their drink. Some plants may be eaten raw, others must be cooked first, others must be processed first (by milling or plant processing) before they are edible, and still others are inedible, producing only non-food products (their seeds may be edible, though). Drinks may be cooked as ingredients in prepared meals, but at least one of the ingredients must be a non-liquid.

All drinks require a spare [[barrel]] or [[large pot]] for storage, and some other products also require specific containers for storage. Plants can be stored in barrels or without a container; seeds are stored individually or in [[bag]]s which can then be put into barrels. It may be advisable to have a small stockpile that accepts only seeds next to your farm(s), since dwarves will happily carry entire pots of seeds across the map to pick up a single seed, leading to cancellation spam and irregular planting.

Plump helmets and pig tails can be harvested 25 days after sowing. All other subterranean crops need about 42 days.

== Standard Plants ==
These are the plants defined in the file plant_standard.txt. Standard plants have been changed very little from the previous version; tiles and colors have been upgaded, and brewing, pressing and processing plants to bags have been reimplemented as reactions, which means these options will be unavailable in the workshop if materials are missing.

{{plant table head}}
{{plant table row|name=Plump helmet|tile=♠|color=5:0|biome=Wet cavern|value=4|drink=Dwarven wine|drinkv=10|eat=y|cook=y}}
{{plant table row|name=Pig tail|tile=τ|color=7:0|seasons={{seasons3||1|1|}}|biome=Wet cavern|value=4|drink=Dwarven ale|drinkv=10|prod=Pig tail thread (p)|prodv=2}}
{{plant table row|name=Cave wheat|tile=τ|color=7:1|seasons={{seasons3||1|1|}}|biome=Wet cavern|value=4|drink=Dwarven beer|drinkv=10|cook=p|prod=Dwarven wheat flour (m)|prodv=20}}
{{plant table row|name=Sweet pod|tile=Φ|color=4:1|seasons={{seasons3|1|1||}}|biome=Wet cavern|value=4|drink=Dwarven rum|drinkv=10|cook=p|prod=Dwarven sugar (m) Dwarven syrup (l)|prodv=20☼ 1001}}
{{plant table row|name=Quarry bush|tile=♣|color=7:0|seasons={{seasons3|1|1|1|}}|biome=Wet cavern|value=4|cook=p|prod=Quarry bush leaves (b) Rock nut paste (m) Rock nut press cake (s) Rock nut oil (s)|prodv=501☼ 1☼ 1☼ 5}}
{{plant table row|name=Dimple cup|tile=♥|color=1:1|biome=Wet cavern|value=4|prod=Dimple [[dye]] (m)|prodv=20}}
{{plant table row|name=Muck root|super=4|tile=τ|color=0:1|biome=Wetland/Wet|value=1|drink=Swamp whiskey|drinkv=5|eat=y|cook=y}}
{{plant table row|name=Bloated tuber|super=4|tile=Φ|color=6:0|biome=Wetland/Dry|value=2|drink=Tuber beer|drinv=10|eat=y|cook=y}}
{{plant table row|name=Kobold bulb|super=4|tile=Φ|color=0:1|biome=Wetland/Wet|value=5|prod=[[Gnomeblight]] (e)|prodv=100}}
{{plant table row|name=Prickle berry|tile=:|color=2:0|biome=Not freezing/Dry|value=1|drink=Prickle berry wine|drinkv=5|eat=y|cook=y}}
{{plant table row|name=Strawberry|tile=:|color=4:0|biome=Not freezing/Dry|value=4|drink=Strawberry wine|drinkv=10|eat=y|cook=y}}
{{plant table row|name=Longland grass|tile=τ|color=6:1|biome=Not freezing/Dry|value=4|drink=Longland beer|drinkv=10|cook=p|prod=Longland flour (m)|prodv=20}}
{{plant table row|name=Valley herb|super=4|tile=ÿ|color=2:1|seasons={{seasons3|1|||}}|biome=Temperate grassland/Dry|value=10|cook=y|prod=[[Golden salve]] (v)|prodv=100}}
{{plant table row|name=Rat weed|tile=τ|color=2:0|biome=Not freezing/Wet|value=1|drink=Sewer brew|drinkv=5|eat=y|cook=y}}
{{plant table row|name=Fisher berry|tile=:|color=7:0|biome=Not freezing/Wet|value=4|drink=Fisher berry wine|drinkv=10|eat=y|cook=y}}
{{plant table row|name=Rope reed|tile=ƒ|color=2:0|biome=Not freezing/Wet|value=4|drink=River spirits|prod=Rope reed thread (p)|prodv=2}}
{{plant table row|name=Blade weed|tile=τ|color=2:0|biome=Not freezing/Dry|value=4|prod=Emerald [[dye]] (m)|prodv=20}}
{{plant table row|name=Hide root|tile=τ|color=6:0|biome=Not freezing/Dry|value=1|prod=Redroot [[dye]] (m)|prodv=10}}
{{plant table row|name=Sliver barb|tile=τ|color=0:1|biome=Not freezing/Dry|align=Evil|value=1|drink=Gutter cruor|drinkv=5|prod=Sliver [[dye]] (m)|prodv=20}}
{{plant table row|name=Sun berry|tile=:|color=6:1|biome=Not freezing/Wet|align=Good|value=9|drink=Sunshine|drinkv=25|eat=y|cook=y}}
{{plant table row|name=Whip vine|tile=§|color=3:1|biome=Not freezing/Dry|align=Savage|value=1|drink=Whip wine|drinkv=15|cook=p|prod=Whip vine flour (m)|prodv=25}}
|}
'''Notes:'''
:1 This is the value for a stack of 5 units, which is the number rendered from a single plant.
:2 Anything that can be cooked is edible afterwards. Note that cooking leaves no seeds for re-planting.
:3 These plants cannot be eaten/cooked until they are further processed, either by milling or extracting; see "products" column for process product.
:4 These plants cannot be grown on a farm plot as they have no seeds. They can only be acquired through plant gathering (in season only) or trade.
:5 To get the products/extracts from the plants they have to be processed, in the following [[workshop]]s, using the following [[labor]]s:
::*'''m''': mill ([[cave wheat]], [[sweet pod]], [[longland grass]], [[whip vine]], [[dimple cup]], [[blade weed]], [[hide root]], [[sliver barb]]): At [[quern]] or [[millstone]], using [[milling]].
::*'''b''': process to bag ([[quarry bush]]): At [[farmer's workshop]], using [[plant processing]].
::*'''s''': press paste into oil ([[quarry bush]]): At [[screw press]].
::*'''l''': process to barrel ([[sweet pod]]): At farmer's workshop, using plant processing.
::*'''p''': process plant ([[pig tail]], [[rope reed]]): At farmer's workshop, using plant processing.
::*'''v''': process to vial ([[valley herb]]): At farmer's workshop, using plant processing.
::*'''e''': extract plant essence ([[kobold bulb]]): At [[still]], using [[plant gathering]].

== Garden Plants ==
All garden plants are above-ground, and can grow year-round. Garden plants are defined in a separate file from standard plants, named, somewhat predictably, plant_garden.txt 
Unlike standard plants, garden plants will also produce growths - leaves, buds, flowers, pods and fruits.
As a general rule, leaves can be only cooked, buds can be both cooked and brewed. // todo: fill in rest; didn't get that far.
{{plant table head}}
{{plant table row|name=Artichoke|tile=:(58)|color=6:0|biome=Temperate grassland/Dry|value=2
|drink=Artichoke wine|drinkv=10|eat=y|cook=y
|prod=leaves (green) heart (purple) flowers seeds
|prodv=?☼ ?☼ ?☼ 1}}
{{plant table row|name=Asparagus|tile=:(58)|color=2:0|biome=Temperate/Dry|value=2
|eat=y|cook=y
|prod=leaves (yellowish-green) flowers (green) fruits (poisonous) seeds
|prodv=?☼ ?☼ ?☼ 1}}
{{plant table row|name=Bambara groundnut|tile=:|color=2:0|biome=Tropical dry broadleaf forest, tropical grassland, tropical savanna, tropical shrubland/Dry|value=2
|eat=y|cook=y
|prod=leaves flowers fruits seeds
|prodv=?☼ ?☼ ?☼ 1}}
{{plant table row|name=String bean|tile=:|color=2:0:1|biome=Temperate/Dry|value=2
|eat=n|cook=y
|prod=leaves flowers pod seeds
|prodv=?☼ ?☼ ?☼ 1}}
{{plant table row|name=Broad bean|tile=:|color=2:0:1|biome=Temperate/Dry|value=2
|eat=n|cook=y
|prod=leaves flowers pod seeds
|prodv=?☼ ?☼ ?☼ 1}}
{{plant table row|name=Beet|tile=:|color=4:0:1|biome=Temperate grassland/Dry|value=2
|drink=beetroot wine|drinkv=10|eat=y|cook=y
|prod=leaves flowers seeds 
|prodv=?☼ ?☼ ?}}
{{plant table row|name=Bitter melon|tile=:|color=2:0:1|biome=Tropical/Dry|value=2
|eat=n|cook=y
|prod=leaves flowers fruit seeds
|prodv=?☼ ?☼ ?☼ ?}}
{{plant table row|name=Cabbage|tile=:|color=2:0:1|biome=Temperate/Dry|value=2
|eat=y|cook=y
|prod=leaves flowers seeds
|prodv=?☼ ?☼ ?☼ ?}}
{{plant table row|name=Caper|tile=:|color=2:0|biome=Desert, Grassland/Dry|value=2
|eat=y|cook=y
|prod=leaves buds flowers fruits seeds
|prodv=?☼ ?☼ ?☼ ?☼ ?}}
{{plant table row|name=Wild carrot|tile=:|color=7:0:1|biome=Temperate/Dry|value=2
|drink=Carrot wine|drinkv=10|eat=y|cook=y
|prod=? seeds
|prodv=?☼ ?}}
{{plant table row|name=Cassava|tile=:|color=2:0:0|biome=Tropical/Dry|value=2
|drink=Cassava beer|drinkv=10|eat=n|cook=y
|prod=? seeds
|prodv=?☼ ?}}
{{plant table row|name=Celery|tile=:|color=2:0:0|biome=Temperate/Dry|value=2
|eat=y|cook=y
|prod=? seeds
|prodv=?☼ ?}}
{{plant table row|name=Chickpea|tile=:|color=2:0:1|biome=Tropical/Dry|value=2
|eat=n|cook=n
|prod=? seeds
|prodv=?☼ ?}}
{{plant table row|name=Chicory|tile=?|color=?|biome=Temperate/Dry|value=?
|eat=y|cook=y
|prod=? seeds
|prodv=?☼ ?}}
{{plant table row|name=Cowpea|tile=?|color=?|biome=Tropical grasslands/Dry|value=?
|eat=?|cook=?
|prod=? seeds
|prodv=?☼ ?}}
{{plant table row|name=Cucumber|tile=?|color=?|biome=Tropical dry broadleaf forest, tropical grassland, tropical savanna, tropical shrubland/Dry|value=?
|eat=?|cook=?
|prod=? seeds
|prodv=?☼ ?}}
{{plant table row|name=Eggplant|tile=?|color=?|biome=Tropical dry broadleaf forest, tropical grassland, tropical savanna, tropical shrubland/Dry|value=2
|eat=?|cook=?
|prod=? seeds
|prodv=?☼ ?}}
{{plant table row|name=Garden cress|tile=?|color=?|biome=Temperate/Dry|value=4
|eat=y|cook=y
|prod=? seeds
|prodv=?☼ ?}}
{{plant table row|name=Garlic|tile=?|color=?|biome=Temperate/Dry|value=?
|eat=?|cook=?
|prod=? seeds
|prodv=?☼ ?}}
{{plant table row|name=Horned melon|tile=?|color=?|biome=Tropical/Dry|value=2
|eat=?|cook=?
|prod=? seeds
|prodv=?☼ ?}}
{{plant table row|name=Leek|tile=?|color=?|biome=Temperate/Dry|value=4
|eat=y|cook=y
|prod=? seeds
|prodv=?☼ ?}}
{{plant table row|name=Lentil|tile=?|color=?|biome=Not freezing/Dry|value=?
|eat=?|cook=?
|prod=? seeds
|prodv=?☼ ?}}
{{plant table row|name=Lettuce|tile=?|color=?|biome=Temperate, tropical dry broadleaf forest, tropical grassland, tropical savanna, tropical shrubland/Dry|value=?
|eat=?|cook=?
|prod=? seeds
|prodv=?☼ ?}}
{{plant table row|name=Mung bean|tile=?|color=?|biome=Tropical/Dry|value=?
|eat=?|cook=?
|prod=? seeds
|prodv=?☼ ?}}
{{plant table row|name=Muskmelon|tile=?|color=?|biome=Temperate,tropical dry broadleaf forest, tropical grassland, tropical savanna, tropical shrubland/Dry|value=?
|eat=?|cook=?
|prod=? seeds
|prodv=?☼ ?}}
{{plant table row|name=Onion|tile=?|color=?|biome=Temperate/Dry|value=2
|eat=?|cook=?
|prod=? seeds
|prodv=?☼ ?}}
{{plant table row|name=Parsnip|tile=:|color=7:0|biome=Temperate/Dry|value=4
|drink=parsnip wine|drinkv=10|eat=y|cook=y
|prod=? seeds
|prodv=?☼ ?}}
{{plant table row|name=Pea|tile=?|color=?|biome=Temperate/Dry|value=2
|eat=?|cook=?
|prod=? seeds
|prodv=?☼ ?}}
{{plant table row|name=Peanut|tile=?|color=?|biome=Tropical dry broadleaf forest, tropical grassland, tropical savanna, tropical shrubland/Dry|value=2
|eat=?|cook=?
|prod=? seeds
|prodv=?☼ ?}}
{{plant table row|name=Pepper|tile=?|color=?|biome=Tropical/Dry|value=?
|eat=?|cook=?
|prod=? seeds
|prodv=?☼ ?}}
{{plant table row|name=Potato|tile=?|color=?|biome=Not freezing/Dry|value=4
|drink=Potato wine|drinkv=10|eat=y|cook=y
|prod=? seeds
|prodv=?☼ 1}}
{{plant table row|name=Radish|tile=?|color=?|biome=Temperate/Dry|value=4
|drink=Radish wine|drinkv=10|eat=y|cook=y
|prod=? seeds
|prodv=?☼ ?}}
{{plant table row|name=Red bean|tile=?|color=?|biome=Temperate/Dry|value=2
|drink=?|drinkv=?|eat=?|cook=?
|prod=? seeds
|prodv=?☼ ?}}
{{plant table row|name=Rhubarb|tile=?|color=?|biome=Temperate/Dry|value=?
|eat=?|cook=?
|prod=? seeds
|prodv=?☼ ?}}
{{plant table row|name=Soybean|tile=?|color=?|biome=Temperate/Dry|value=2
|eat=?|cook=?
|prod=? seeds
|prodv=?☼ ?}}
{{plant table row|name=Spinach|tile=?|color=?|biome=Temperate/Dry|value=?
|eat=?|cook=?
|prod=? seeds
|prodv=?☼ ?}}
{{plant table row|name=Squash|tile=?|color=?|biome=Tropical/Dry|value=?
|eat=?|cook=?
|prod=? seeds
|prodv=?☼ ?}}
{{plant table row|name=Sweet potato|tile=?|color=?|biome=Tropical/Dry|value=?
|drink=Sweet potato wine|drinkv=10|eat=?|cook=?
|prod=? seeds
|prodv=?☼ ?}}
{{plant table row|name=Taro|tile=?|color=?|biome=Tropical/Dry|value=2
|eat=n|cook=y
|prod=leaves flowers seeds
|prodv=?☼ ?}}
{{plant table row|name=Tomato|tile=?|color=?|biome=Tropical dry broadleaf forest/Dry|value=?
|drink=Tomato wine|drinkv=10|eat=?|cook=?
|prod=? seeds
|prodv=?☼ ?}}
{{plant table row|name=Tomatillo|tile=?|color=?|biome=Tropical dry broadleaf forest, tropical grassland, tropical savanna, tropical shrubland/Dry|value=?
|drink=Tomatillo wine|drinkv=10|eat=?|cook=?
|prod=? seeds
|prodv=?☼ ?}}
{{plant table row|name=Turnip|tile=?|color=?|biome=Temperate/Dry|value=?
|drink=Turnip wine|drinkv=10|eat=?|cook=?
|prod=? seeds
|prodv=?☼ ?}}
{{plant table row|name=Urad bean|tile=?|color=?|biome=Tropical/Dry|value=?
|eat=?|cook=?
|prod=? seeds
|prodv=?☼ ?}}
{{plant table row|name=Watermelon|tile=?|color=?|biome=Tropical/Dry|value=2
|eat=?|cook=?
|prod={{tile|♠|2:0}} leaves {{tile|♣|6:0}} flowers {{tile|o|2:0}} fruit seeds
|prodv=?☼ ?}}
{{plant table row|name=Winter melon|tile=?|color=?|biome=Tropical/Dry|value=?
|eat=?|cook=?
|prod={{tile|♠|2:0}} leaves {{tile|♣|6:0}} flowers {{tile|o|2:0}} fruit seeds
|prodv=?☼ ?}}
{{plant table row|name=Lesser yam|tile=?|color=?|biome=Tropical/Dry|value=4
|eat=?|cook=?
|prod=? seeds
|prodv=?☼ ?}}
{{plant table row|name=Long yam|tile=?|color=?|biome=Temperate/Dry|value=4
|eat=y|cook=y
|prod=? seeds
|prodv=?☼ ?}}
{{plant table row|name=Purple yam|tile=?|color=?|biome=Tropical/Dry|value=4
|eat=?|cook=?
|prod=? seeds
|prodv=?☼ ?}}
{{plant table row|name=White yam|tile=?|color=?|biome=Tropical/Dry|value=4
|eat=?|cook=?
|prod=? seeds
|prodv=?☼ ?}}
{{plant table row|name=Passion fruit|tile=?|color=?|biome=Tropical/Dry|value=2
|drink=Passion fruit wine|drinkv=10|eat=?|cook=?
|prod=? seeds
|prodv=?☼ ?}}
{{plant table row|name=Grape|tile=?|color=?|biome=Temperate/Dry|value=2
|drink=Wine|drinkv=10|eat=y|cook=y
|prod=? seeds
|prodv=?☼ ?}}
{{plant table row|name=Cranberry|tile=?|color=?|biome=Temperate, tundra, taiga/Dry|value=?
|drink=Cranberry wine|drinkv=10|eat=?|cook=?
|prod=? seeds
|prodv=?☼ ?}}
{{plant table row|name=Bilberry|tile=?|color=?|biome=Temperate, tundra, taiga/Dry|value=2
|drink=Bilberry wine|drinkv=10|eat=?|cook=?
|prod=? seeds
|prodv=?☼ ?}}
{{plant table row|name=Blueberry|tile=?|color=?|biome=Temperate, tundra, taiga/Dry|value=2
|drink=Blueberry wine|drinkv=10|eat=y|cook=y
|prod=? seeds
|prodv=?☼ ?}}
{{plant table row|name=Blackberry|tile=?|color=?|biome=Temperate/Dry|value=2
|drink=Blackberry wine|drinkv=10|eat=?|cook=?
|prod=? seeds
|prodv=?☼ ?}}
{{plant table row|name=Raspberry|tile=?|color=?|biome=Temperate/Dry|value=2
|drink=Raspberry wine|drinkv=10|eat=?|cook=?
|prod=? seeds
|prodv=?☼ ?}}
{{plant table row|name=Pineapple|tile=?|color=?|biome=Tropical/Dry|value=?
|drink=Pineapple wine|drinkv=10|eat=?|cook=?
|prod=? seeds
|prodv=?☼ ?}}
|}
'''Notes:'''
:1 This is the value for a stack of 5 units, which is the number rendered from a single plant.
:2 Anything that can be cooked is edible afterwards. Note that cooking leaves no seeds for re-planting.
:3 These plants cannot be eaten/cooked until they are further processed, either by milling or extracting; see "products" column for process product.
:4 These plants cannot be grown on a farm plot as they have no seeds. They can only be acquired through plant gathering (in season only) or trade.
:5 Some products may require processing; see plant page for details.

== Crop Plants ==
These plants are defined in the file plant_crops.txt. They grow above ground, in any season.

{{plant table head}}
{{plant table row|name=Single-grain wheat|tile=?|color=?|biome=Tropical Savannah, Grassland|value=2
|drink=Single-grain wheat beer|drinkv=10|eat=n|cook=p
|prod=? seeds
|prodv=?☼ ?}}
{{plant table row|name=Two-grain wheat|tile=?|color=?|biome=Tropical Savannah, Grassland|value=2
|drink=Two-grain wheat beer|drinkv=10|eat=n|cook=p
|prod=Two-grain wheat flour (m) seeds
|prodv=20☼ 1}}
{{plant table row|name=Soft wheat|tile=?|color=?|biome=Tropical Savannah, Grassland|value=?
|drink=Soft wheat beer|drinkv=10|eat=n|cook=p
|prod=? seeds
|prodv=?☼ ?}}
{{plant table row|name=Hard wheat|tile=?|color=?|biome=Tropical Savannah, Grassland|value=?
|drink=Hard wheat beer|drinkv=10|eat=?|cook=?
|prod=? seeds
|prodv=?☼ ?}}
{{plant table row|name=Spelt|tile=?|color=?|biome=Any Temperate|value=4
|drink=Spelt beer|drinkv=10|eat=?|cook=p
|prod=Spelt flour (m) Spelt seeds
|prodv=20☼ 1}}
{{plant table row|name=Barley|tile=?|color=?|biome=Not freezing|value=2
|drink=Barley wine|drinkv=10|eat=n|cook=p
|prod=Barley flour (m) seeds
|prodv=20☼ ?}}
{{plant table row|name=Buckwheat|tile=?|color=?|biome=Tropical dry broadleaf forest|value=?
|drink=Buckwheat beer|drinkv=10|eat=n|cook=p
|prod=? seeds
|prodv=?☼ ?}}
{{plant table row|name=Oats|tile=?|color=?|biome=Any Temperate|value=2
|eat=n|cook=p
|prod=Oat flour (m) Oat seeds
|prodv=?☼ ?}}
{{plant table row|name=Alfalfa|tile=?|color=?|biome=Not freezing|value=4
|eat=?|cook=y
|prod=? seeds
|prodv=?☼ ?}}
{{plant table row|name=Rye|tile=?|color=?|biome=Not freezing|value=2
|drink=Rye beer|drinkv=10|eat=n|cook=p
|prod=Rye flour (m) seeds
|prodv=20☼ 1}}
{{plant table row|name=Sorghum|tile=?|color=?|biome=Tropical Savannah, Grassland|value=?
|drink=Sorghum beer|drinkv=10|eat=?|cook=?
|prod=? seeds
|prodv=?☼ ?}}
{{plant table row|name=Rice|tile=?|color=?|biome=Any tropical|value=2
|drink=Rice beer|drinkv=10|eat=?|cook=?
|prod=Rice flour (m) seeds
|prodv=20☼ 1}}
{{plant table row|name=Maize|tile=?|color=?|biome=Any tropical|value=?
|drink=Maize beer|drinkv=10|eat=?|cook=?
|prod=? seeds
|prodv=?☼ ?}}
{{plant table row|name=Quinoa|tile=?|color=?|biome=Any temperate|value=?
|drink=Quinoa beer|drinkv=10|eat=n|cook=p
|prod=Quinoa flour (m) seeds
|prodv=20☼ 1}}
{{plant table row|name=Kaniwa|tile=?|color=?|biome=Any temperate|value=2
|drink=Kaniwa beer|drinkv=10|eat=n|cook=p
|prod=Kaniwa flour (m) seeds
|prodv=20☼ 1}}
{{plant table row|name=Bitter vetch|tile=?|color=?|biome=Any temperate|value=?
|eat=?|cook=y
|prod=? seeds
|prodv=?☼ ?}}
{{plant table row|name=Pendant amaranth|tile=?|color=?|biome=Any tropical|value=?
|drink=Pendant amaranth beer|drinkv=10|eat=?|cook=?
|prod=? seeds
|prodv=?☼ ?}}
{{plant table row|name=Blood amaranth|tile=?|color=?|biome=Any tropical|value=2
|drink=Blood amaranth beer|drinkv=10|eat=?|cook=n
|prod=Blood amaranth flour (m) seeds
|prodv=20☼ 1}}
{{plant table row|name=Purple amaranth|tile=?|color=?|biome=Any temperate|value=2
|drink=Purple amaranth beer|drinkv=10|eat=n|cook=n
|prod=Purple amaranth flour (m) seeds
|prodv=20☼ 1}}
{{plant table row|name=Red spinach|tile=?|color=?|biome=Not freezing|value=2
|eat=y|cook=y
|prod=? seeds
|prodv=?☼ ?}}
{{plant table row|name=Elephant-head amaranth|tile=?|color=?|biome=Any tropical|value=2
|eat=?|cook=n
|prod=? seeds
|prodv=?☼ ?}}
{{plant table row|name=Pearl millet|tile=?|color=?|biome=Any tropical|value=2
|drink=Pearl millet beer|drinkv=10|eat=n|cook=p
|prod=Pearl millet flour (m) Plant Millet
|prodv=20☼ 1}}
{{plant table row|name=White millet|tile=?|color=?|biome=Any temperate|value=2
|drink=White millet beer|drinkv=10|eat=n|cook=p
|prod=White millet flour (m) seeds
|prodv=20☼ ?}}
{{plant table row|name=Finger millet|tile=?|color=?|biome=Any temperate|value=2
|drink=Finger millet beer|drinkv=10|eat=n|cook=p
|prod=Finger millet flour (m) Finger Millet
|prodv=20☼ 1}}
{{plant table row|name=Foxtail millet|tile=?|color=?|biome=Any temperate|value=2
|drink=Foxtail millet beer|drinkv=10|eat=n|cook=p
|prod=Foxtail millet flour (m) seeds
|prodv=20☼ ?}}
{{plant table row|name=Fonio|tile=?|color=?|biome=Tropical Savannah|value=2
|drink=Fonio beer|drinkv=10|eat=?|cook=y
|prod=Fonio flour (m) seeds
|prodv=20☼ 1}}
{{plant table row|name=Teff|tile=?|color=?|biome=Tropical Grassland|value=2
|drink=Teff beer|drinkv=10|eat=?|cook=?
|prod=? seeds
|prodv=?☼ ?}}
{{plant table row|name=Flax|tile=?|color=?|biome=Tropical Savannah, Grassland|value=2
|eat=n|cook=p
|prod=Flax plant fiber thread Flax flour Flax seed paste (m) Flax seed press cake (s) Linseed oil (s)
|prodv=12☼ 20☼ 1☼ 1☼ 5}}
{{plant table row|name=Jute|tile=?|color=?|biome=Any tropical|value=2
|eat=n|cook=n
|prod=Jute plant fiber thread seeds
|prodv=12☼ 1}}
{{plant table row|name=Hemp|tile=?|color=?|biome=Any temperate|value=2
|eat=n|cook=p
|prod=Hemp plant fiber thread Hemp flour Hemp seed paste (m) Hemp seed press cake (s) Hempseed oil (s)
|prodv=12☼ 20☼ 1☼ 1☼ 5}}
{{plant table row|name=Cotton|tile=?|color=?|biome=Any tropical|value=2
|eat=n|cook=n
|prod= Cotton plant fiber thread Cotton seed paste (m) Cotton seed press cake (s) Cotton seed oil (s)
|prodv=12☼ 1☼ 1☼ 5}}
{{plant table row|name=Ramie|tile=?|color=?|biome=Any tropical|value=2
|eat=n|cook=n
|prod=Ramie plant fiber thread Kenaf seed paste (m) Kenaf seed press cake (s) Kenaf seed oil (s)
|prodv=12☼ 1}}
{{plant table row|name=Kenaf|tile=?|color=?|biome=Any tropical|value=2
|eat=n|cook=n
|prod=Kenaf plant fiber thread seeds
|prodv=12☼ 1☼ 1☼ 5}}
{{plant table row|name=Papyrus sedge|tile=?|color=?|biome=Any tropical wetland|value=?
|eat=?|cook=?
|prod=? seeds
|prodv=?☼ ?}}
|}
'''Notes:'''
:1 This is the value for a stack of 5 units, which is the number rendered from a single plant.
:2 Anything that can be cooked is edible afterwards. Note that cooking leaves no seeds for re-planting.
:3 These plants cannot be eaten/cooked until they are further processed, either by milling or extracting; see "products" column for process product.
:4 These plants cannot be grown on a farm plot as they have no seeds. They can only be acquired through plant gathering (in season only) or trade.
:5 Some products may require processing; see plant page for details.

==Bugs==

* Plant handling/processing is incomplete for some crops.{{bug|6940}} This results in plants that, when picked, are inedible because the wrong parts are picked, or where seeds are impossible to pull from the proper plant parts. Large numbers of crops are therefore incapable of being farmed.

== See also ==
* [[Farming]]