Editing Siege engine

{{Quality|Unrated}}

A '''siege engine''' in ''Dwarf Fortress'' is half building, half heavy weapon, and includes both the '''catapult''' and the '''ballista'''.  Both are capable of launching hazardous projectiles at a tremendous range (more than a screen-width, around 80 to 100 tiles for a catapult and between 130 and 200 tiles for a ballista).  A [[ballista arrow]] can kill or injure each creature in its path indiscriminate of friend or foe, but a stone launched from a catapult cannot harm [[dwarf|dwarves]] or [[animal trainer|tamed animals]].

Ballistae require specially-made [[ammo]] – [[ballista arrow]]s, made from [[wood]]en [[log]]s at the [[siege workshop]] (and optionally tipped with [[metal]] [[ballista arrowhead]]s that have been made at a [[forge]] by a [[weaponsmith]]). Catapults use simple [[stone]] as ammunition. Catapults respect [[economic stone]] restrictions and cannot fire [[clay]] at all.

 

In order to build a siege engine, you first need to produce (at least) three catapult or ballista parts in the [[siege workshop]]; catapults are made from any 3 '''catapult parts''', and ballistae are made from any 3 '''ballista parts'''. All parts are made from any type of wood at the siege workshop. Beyond that, "parts" are generic - there are no particular "sub-types" of parts beyond the distinction between those for the two different engine types. The quality of the parts determines the overall rate of fire (and maybe accuracy) of the engine - the best are made with 3 masterwork parts{{verify}}. This won't make up for an untrained siege operator, but every little bit helps. Siege engine parts are stored in Furniture stockpiles.

The assembled siege engine is, effectively, a 3x3 building. It cannot be moved about, other than by taking it down and re-assembling it at the new site. Siege engines do not impede movement, though, so you don't have to worry about building them in a corridor.

*Prepare to Fire:  Siege operators will load the engine and remain stationed for further commands.

*Fire at Will:  Siege operators will fire and load normally.

Since catapults will never hurt your dwarves, you can easily take the above designs and face the catapults towards each other with channels behind them.

This is obviously only for training purposes, but the point is efficiency.  As each catapult fires, it "gives" stones to the engine across from it.  This is entirely self contained, as your operators will continuously recycle the same ammunition, practically playing "catch" with the stones they are training with.  Stones will always be available directly behind each operator, however <s>dorfs</s> some dwarves are incredibly stupid.  They will tend to pick the last MINED stone for loading (like masons and crafters), so its best to burrow them into the range.  Even then, the idiots will sometimes cross the range and pick up stones from the far end.

* Both catapults and ballistae have narrow fields of fire – they will only shoot at creatures directly "in front" of them, and so cannot target anything off at an angle.  They can be turned 90 degrees, but that often will not solve the problem. Unskilled operators have trouble aiming perfectly straight, and their shots will randomly veer off to either side, resulting in a field of fire roughly 19 degrees across. Highly skilled operators fire their shots perfectly straight, restricting their field of fire to a straight line facing directly north/south/east/west.

* Both catapults and ballistae aim and fire only along one z-level.  While ammo from both may drop down z-levels, they do no damage to creatures there. This also means that no "head room" is necessary – ammo only flies out, never up.

* Catapults have a minimum range – at least 30 tiles.

* [[Siege operator]]s are civilians and, as such, will run in fear if enemy units come too close to them. "Too close" varies somewhat, but may be as far as 10 tiles.

 

 

Siege engines can shoot through [[fortification]]s, just like any other projectile weapon. As fortifications appear to provide some protection against incoming [[bolt]]s and [[arrow]]s, it's usually a good idea to protect the siege engine in that way. The siege engine can shoot through any tile thickness of fortification. Fortifications further on in the path of the shot will not hinder it either.

  Entrance++++++++++++▼    ╬  ╬▐▀\◄═«  (~ammo~)

  Entrance++++++++++++▼    ╬▐▀\◄═«▐▄/

  Entrance++++++++++++▼    ╬◄═«▐▄/ (~ammo~)

  ══════════════════════════╣▐▄/ (~ammo~)

 

:*<tt>＋</tt> - floor

An alternate strategy could be to place a [[floodgate]] or retracting [[bridge]] in the center of the 3x3 hallway, and activate it during times of crisis so that the Goblins are forced to fight in two separate 1x1 corridors rather than a single 3x3 corridor. If the corridors are further lined with spike traps and weapon traps, this combined defense can assure your dwarves that any attempts to assault your base will be very, very bloody.

A drawbridge can be combined with the channeled area to provide a practice area, as discussed above.  The channels would be accessible from the battery area via a staircase, keeping the dwarves below/behind the lines of fire at all times.

When a catapult throws a stone, that stone is destroyed upon landing, unless it falls a z-level, where it lands harmlessly.  That means that if you can arrange it so ammo hits a wall (or door, or raised bridge), and there is empty space immediately under that, the stone arrives at that point.  If the ammo reaches its maximum range, again, it falls harmlessly.  Even with a single, no-quality catapult and an untrained crew, this is massively faster than hauling stone by hand.  Ammo that hits [[stairs]] is destroyed, even if it can fall a z-level. Stones falling one z-level onto a floor with empty space under it will also be destroyed, make sure there is a wall under the tile where the ammo ultimately lands on.

:*[[cross-training#Artillery proving ground (siege operator)|Army corps of engineers]]