Editing User:Nagidal/Sandbox

[[File:Double-slit-name.png‎|frame|right|The two name-giving slits are highlighted]]

QuantumMenace has developed a very easy method how to dig through an [[DF2012:Aquifer|aquifer]] of an unknown depth commonly known as the '''double-slit method'''. Its name derives from two channeled-out slits at the sides of a 2&times;2 area.

The slits are used to break into the aquifer layer below, hence their ramps are flooded (blue). Water can be pumped from one slit to another slightly faster than the aquifer is flooding it. While a dwarf operates the pump, another dwarf can access the source slit via the ramp and seal off the surrounding walls of the aquifer one by one.

== Draining an aquifer ==

Aquifers produce infinite amounts of water, but they can also absorb infinite amounts of it. We can drain an aquifer into itself either within one z-level or across multiple z-levels. 

=== Draining across multiple z-levels ===

QuantumMenace's double slit method uses this kind of aquifer draining for all but the lowest aquifer level. It is more convenient to use the lower aquifer level to absorb all of the water being produced by the aquifer level above it. 

{|class="wikitable1"
|-valign="top" 
| [[Image:Aquifer draining.png|left|350px|]]
|}

This only works if you crack open the lower aquifer level. You can achieve this by digging stairs or channeling into the lower aquifer level while the upper aquifer level is being pumped dry. After that, the lower aquifer level will be able to receive any water from above.

=== Drain within one z-level ===

The double-slit method uses this for the lowest aquifer level. Here we pump out the water from a tile being flooded by the aquifer to the level above it and let it flow back down to another tile where it becomes absorbed by the same aquifer layer again. Note that the target tile of the aquifer must be cracked open (e.g. by downstairs or a channel) to be able to receive water.

{|class="wikitable1" style="padding-top: 2em"
|-valign="top" 
| [[Image:Aquifer_pump_scheme.png|left|600px|Water flow between the two slits.]]
|}


== Tutorial embark setup ==
The double-slit method will be presented in a form of a play-along tutorial. Train it on an embark which you don't intend to play after you've made it through the aquifer. Try to embark at some forested place near the ocean where multi-level aquifers are almost guaranteed. Take this embark setup:

* 1 Proficient Miner
* 4 Proficient Carpenters
* 2 Proficient Wood cutter

You can sell the anvil, one pick, and all quivers, splints and crutches to buy loads of wooden logs. It will save you time cutting down trees.

Make sure you have at least one (battle) axe and one 1 pick to cut down trees and mine.

== Procedure ==

=== Preparation ===

Using your logs of wood, build a carpenter's workshop and craft all the parts necessary to build a pump, i.e.:

* a [[DF2012:Block|block]]<br />
* an [[Trap_components#Enormous_corkscrew|enormous corkscrew]]
* a [[DF2012:Pipe section|pipe section]]

=== Digging through the aquifer ===

Dig a 2&times;2 staircase until you reach the aquifer layer.

{|class="wikitable1"
|-valign="top" 
| [[Image:Safe-layer.png‎|frame|left|Your last non-aquifer layer]]
| [[Image:Aq01.png‎|frame|left|Your first aquifer layer]]
|}

1. Make yourself an access to the aquifer layer:

{|class="wikitable1"
|-valign="top" 
| [[Image:Aq02.png‎|frame|left|1. Channel out one tile at each side of your staircase like this.]]
| [[Image:Aq03.png‎|frame|left|2. This is how the aquifer level looks now.]]
|-valign="top" 
| [[Image:Aq04.png|frame|left|3. Build a floor replacing the stairs between the channels.]]
| [[Image:Aq05.png|frame|left|4. Build a pump there, pumping from the west (make sure one of your dwarves has the [[DF2012:Building designer|architecture]] labor enabled).]]
|}

2. Make sure you have at least one dwarf with the [[DF2012:Pump_operator|pump operating]] labor enabled. Start pumping the water from one side to another. And build walls around the first quadrant.

{|class="wikitable1"
|-valign="top" 
| [[Image:Aq06.png|frame|left|1. Designate these two tiles to be dug]]
| [[Image:Aq07.png|frame|left|2. First build the wall on the south (expect a lot of cancellation spam).]]
|-valign="top" 
| [[Image:Aq08.png|frame|left|3. Then the wall on the north]]
| [[Image:Aq09.png|frame|left|4. Then these two walls (build them one by one).]]
|}

3. Deconstruct the water pump, build it facing the other direction and start pumping again. Build walls around the second quadrant accordingly.

{|class="wikitable1"
|-valign="top" 
| [[Image:Aq10.png|frame|left|1. Start with the southern one]]
| [[Image:Aq11.png|frame|left|2. Proceed until you achieve this]]
|}

4. Deconstruct the pump and the floor tiles in your non-aquifer layer and construct an up/down staircase there instead.

{|class="wikitable1"
|-valign="top" 
| [[Image:Aq12.png|frame|left|1. Pump and floor deconstructed]]
| [[Image:Aq13.png|frame|left|2. Stairs built]]
|}

5. The procedure for building walls in the third quadrant differs slightly from what you have been building until now.

{|class="wikitable1"
|-valign="top" 
|[[Image:Aq14.png|frame|left|1. Dig a channel to the left and right and build a water pump between them (e.g. pumping from the east) and start pumping.]]
|[[Image:Aq15.png|frame|left|2. Don't dig under your stairs. Instead, build a wall in place of the south-eastern channel tile.]]
|-valign="top" 
|[[Image:Aq16.png|frame|left|3. Continue walling off the the third quadrant by building this wall in the north.]]
|[[Image:Aq17.png|frame|left|4. Proceed building in until it looks like this. You mustn't dig the wall under the stairs. It will serve us as water sink.]]
|}


6. Now for the last quadrant. We deliberately haven't dug the North-East wall under the stairs. Despite it being aquifer and leaking water, we need it to use it as a water sink now. Remember, aquifers can receive infinite amount of water, too. Deconstruct the pump and build it to pump to the opposite direction. It will spill some water on its level while pumping, but it isn't dangerous.

{|class="wikitable1"
|-valign="top" 
|[[Image:Aq18.png|frame|left|1. Designate these two aquifer walls to be dug.]]
|[[Image:Aq19.png|frame|left|2. Proceed with the northern wall.]]
|-valign="top" 
|[[Image:Aq20.png|frame|left|3. Then bulid these other three walls.]]
|[[Image:Aq24.png|frame|left|4. Deconstruct the pump and the floors and construct Up/Down stairs there.]]
|}

7. We will now deal with the last piece of aquifer. 

{|class="wikitable1"
|-valign="top" 
|[[Image:Aq21.png|frame|left|1. Deconstruct the wall marked with the "C" to gain access to the last aquifer tile. Aquifers don't leak diagonally, so we are safe here.]]
|[[Image:Aq22.png|frame|left|2. Mine the last piece of the aquifer on this level.]]
|-valign="top" 
|[[Image:Aq23.png|frame|left|3. It will produce 7 units of water wetting the ground a bit.]]
|[[Image:Aq25.png|frame|left|4. Dig downstairs to check whether there is another aquifer layer below.]]
|}

When you are digging the downstairs, better have the game paused and proceed step by step ({{K|.}} One-Step). There is usually some water on the level where you are digging from, which would immediately run down the stairs you're digging and make the level below damp. The only way to tell whether there is an aquifer below is to stop the at the very moment when your miner reveals the first tile of it. If it is damp before the water from your level has run down on it, it is another aquifer level.

{|class="wikitable1"
|-valign="top" 
|[[Image:Aq26.png|frame|left|5. Construct up/down stairs on top of the downstairs to have an access to this level once the ramps are removed.]]
|[[Image:Aq27.png|frame|left|6. Deconstruct the redundant walls.]]
|}

8. Level done

{|class="wikitable1"
|-valign="top" 
|[[Image:Aq28.png|frame|left|Enjoy your first secured aquifer layer.]]
|}

If you see there is another aquifer layer below, you repeat the steps in sections 1-8. To dig through one layer of aquifer this way will take you 2 or 3 months in-game time.

==Links==
[http://www.bay12forums.com/smf/index.php?topic=79224.msg2060636#msg2060636| Quantum's original forum post]