Editing Pump-stack method

kingbu posted this novel approach to [[Aquifer]] piercing over on the bay12 forums. Unfortunately his original twitch video has since been taken down; however, this tutorial is based extensively on that video, adding only a few improvements that have since been made to the method.  Kingbu's method, which he termed the no-cancellation-spam method but is here called the pump-stack method, is significantly faster than the famed [[Double-slit method]] but does require significantly more materials and labors since it involves building a double [[Screw_pump#Pump_stack|Pump stack]].  In it's simplest form, the method draws heavily on the [[Water_wheel#Dwarven_Water_Reactor|Dwarven water reactor]] exploit, so it may not be for everyone.  However, it is entirely possible to accomplish the method without the exploit, but it is significantly slower as you will need to build an extensive [[Power|power system]] to run the pump stack.

=== Double Slit Method ===

Go and read the the [[Double-slit method|double-slit method tutorial]], and possibly run through it with an aquifer.  Knowing the basics of how aquifers drain is crucial to getting this method to work.  Take particular note of the [[Double-slit_method#Draining_an_aquifer|draining an aquifer]] section.

=== Pump Stacks ===

== The embark ==

Embark in an area with an aquifer and plenty of trees.  Picking an area with deep soil increases your chance of getting a multi-level aquifer to practice on.  It is recommended that you try ass flat of an area as possible for your first attempt.  Picking a calm site with invaders turned off will provide a less distracting learning environment.

The first things you'll want to do is queue a lot of trees for cutting, build three carpenter's workshops, a mechanic's workshop, and dig a 4x3 shaft of stairs down from the surface until you hit aquifer.  Of importance, dig the shaft one set of stairs at a time and check the level below the stairs before you dig the soil.  Stop as soon as you see the damp soil.  Do not dig stairs in it yet.

* 6 [[Pipe second|wooden pipe sections]]

Next, pause the game and set up a 4x3 dig stairs designation starting in the aquifer and extending 10 or so levels down.  This will be used to test for aquifer as you descend.  More on this in a bit.

Unpause the game and wait for your miner to dig out one of the marked tiles.  You're looking for a damp stone cancellation.  If you get one after the tile is dug, that means there is more than one level of aquifer.

If you get a cancellation, remove the up/down stairs designation on the new damp-stone layer.  Then unpause the game and let your miners finish digging out the top layer of the aquifer.  If you don't get a cancellation, pause the game, remove the designation, finish this section and then proceed to the "last layer" section.

Now it's time to build the first set of [[Screw pumps|screw pumps]], some [[Gear assembly|gear assemblies]], and the [[Water wheel|water wheel]] that will run the show.  The pumps should be set to pump out of the stairway and into the drain.  In this case, pump from East to West.  You'll do this part in two steps. First the two pumps and the wheel gear assembly, and then the wheel and hanging gear.  See below.

| [[Image:Pump_aquifer_top_wheel.png|frame|left|Next, build a waterwheel attached to the bottom gear assembly, and construct an assembly next to the top pump, hanging over the channel*]]

*If your aquifer is only 1 layer thick, you do not need this gear assembly.

Now, that your pumps are built and the power is ready, it's time to start them up.  Channel out that missing tile and it'll start the pumps (otherwise you can always enable pumping labor on somebody and just start them manually). Of note, you'll get a little splatter when it starts up.  This is normal and nothing to worry about.  It stops immediately and will evaporate after a minute or two.

Now that your pumps are working, you can see that you've created a few safe places in your staircase to work.  How you go about doing that depends on if you have multiple layers of aquifer.

If your aquifer is only 1-layer deep, go to the "last level" section, and follow the directions there.  Otherwise proceed to the next section.

If you're current pumped layer has another layer of aquifer below it, then the first thing you need to do is drill down into that aquifer layer and see if there is another aquifer layer below that.  To do this, dig up/down stairs under the top right set of stairs in the pit.  This corresponds to the tile that is being actively pumped dry by the top of the two pumps.  Once again, you're looking for a damp stone cancellation once the stairs are dug.  Once you dig those stairs and either get a cancellation or not, remove the up/down stairs designation on the layer below the one you just dug the stairs in and continue.

At this point, you're ready to dig out the aquifer underneath your pumping layer.  It's best to do this one row at a time as this avoids dangerous terrain cancellations.

| [[Image:Pump_aquifer_first_first_row.png|frame|left|Starting just below your pilot hole, dig up/down stairs one row at a time.]]

| [[Image:Pump_aquifer_first_second_row.png|frame|left|You do it one row at a time to avoid cancellations due to the water up above creating dangerous terrain.]]

| [[Image:Pump_aquifer_first_fourth_row.png|frame|left|Last row!  Once this row is done, the aquifer layer directly above this one will be draining directly into this layer.]]

=== Walling Off and Extending the Stack ===

Walling off the aquifer is extremely easy in the pump-stack method.  All you do is dig out every other tile around the staircase, and then put a wall there.  You'll almost never get build suspensions doing the walling like this, which is why it was originally pitched as a "no-job-suspension" method.

Doing everything that's left is every bit as easy.  Just designate all the remaining aquifer tiles (being mindful to ignore the diagonal tiles) and replace them with walls.

| [[Image:Pump_aquifer_second_draining.png|frame|left|Just like with the first level, you have a little room to work with on the left, which is enough to get started.]]

From here on out each aquifer level is pretty much the same.  You dig your pilot up/down stairs into the next level to see if there's an aquifer below that one, make a note if you find more aquifer or not, cancel the designations, dig out the level to create a drain, wall off the level, add the pumps, and move to the next.

Since your pumps are creating your work spot in the top-right of the next level, you dig your up/down stairs below the top-right tile.

| [[Image:Pump_aquifer_fourth_damp.png‎|frame|left|In this case, there's another damp stone designation cancellation. That means more aquifer.  Cancel the rest of the up/down stair designations on this level.]]

Once you've done your pilot hole, use up/down stairs to dig out the level one row at a time.

And with that, you're ready for the next level.  Just keep adding on to your pump stack until you finally dig a pilot hole without a damp stone cancellation.  Once you get that cancellation, finish off the walling of your current layer, and proceed to the last layer section.

| [[Image:Pump_aquifer_top_wheel2.png‎|frame|left|A second wheel added to the power generator. In the unlikely event that you need a third wheel, just extend the wall to the West and dig another row into the drain.]]

The lowest layer is always the problem layer for any aquifer pierce method because there's nothing to drain it directly into.  The double-slit method is able to get around this by draining small spaces and utilizing clever wall building and evaporation to finish off the last layer.  Unfortunately, that isn't an option here.

Once you've found the bottom layer, you'll be looking at something like this just under where you dug your pilot hole.  At this point you may as well cancel not only this set of designations, but all other remaining designations you put in place to locate the damp stone.  At this point, you have an opportunity to check your work.  There will be a single visible tile under the pilot hole.  If this tile is a layer stone, or something that doesn't appear in sedimentary rock, then you're in the clear.  If it's ore, gems, or stone that can appear in sedimentary layers, then proceed carefully, as you might just be digging into an ore vein and might still have some aquifer to deal with.

Once you've got your pump-stack on the layer above the bottom in place and they're pumping water out of the lowest layer, it's time to finally use that hatch cover you built near the beginning of this pierce.  Have the hatch cover built in the corner you would normally use to dig a pilot hole.  You are probably going to get a lot of build suspensions when placing this hatch cover.  Just keep unsuspending it and it'll eventually get built.

Once the hatch cover is down, close it firmly so you don't get animals down there.  If at any point you built a stone stockpile or have stone enabled on any stockpile in your fort, now is a good time to disable those stockpiles.  You want to prevent anyone but miners from going through the hatch you just built, so preventing animal pathing and stone-collection keeps out dwarves who shouldn't be down there.  That hatch cover is to hold back the water while your miners dig a drain.

With the drain ready, it's not time to connect it to the bottom layer of your aquifer.  You do this by digging out up/down stairs in the same 4x3 area that the rest of the starcase is in.  Dig them starting at your drain and move upwards one floor at a time, connecting the shaft to your aquifer layer at the very end.

*Q: Why use this method instead of the 2-slit method.

*A: This method is quite a bit faster.  You can breach a 7-layer aquifer in 3 months with this method, which is less than half the time a 2-slit method would take.  It also involves a ton less cancellation spam on the buildings.  In a typical breach, likely you'll only see a few designation cancels here and there, and the suspension spam on the hatch cover.