IntroductionSo, you've slaughtered goblins by the thousand, dined with clowns and on clowns in the circus tent, launched kittens into orbit, and yet you're still looking for a challenge. It's thrown about that there's one true last dwarven frontier: the magma sea.
Colonizing the bottom of the magma sea is something that has never been done before to my knowledge. I did find an
old post describing a method to cast an obsidian wall on the bottom layer, but having tested it thoroughly, I can't find any interpretation of the method that works in this version (0.34.11), nor any evidence that anyone actually ever did it. In any case, I'm sure no one has done a writeup in this level of detail before, so it may be of some use even if it's not a first.
Although this is definitely an advanced project, I've done my best to write a guide which a moderately experienced player ought to be able to understand. If there's anything I could explain better or anything I left out (fairly likely, I'm sure), please let me know.
1) You'll need a LOT of water. Having an aquifer is a big help, but you may be able to make do with just cavern water. If you intend to do so, I'd build a big cistern and start saving up right away. Update 12/22/13: If you use the new technique, you need MUCH less water; all you need is a source for filling buckets.
2) A place to put a lot of excess magma. For this purpose, conquering the HFS is highly recommended, but in theory you should be able to pump the magma into the caverns or even atom-smash it.
3) Expendable dwarves. I'm not sure you're ever truly forced to sacrifice a dwarf, but let's face it, there will be accidents.
By the way, your fps will be really, really, bad during bottom layer operations. Fortunately. it will get better when you finish.
Also, it goes without saying you need to use magma-safe materials.
If you have to ask, you shouldn't.
Of course, the key to draining the magma sea is to block off the magma sources on the map's edge. Because magma is not pressurized, once you block all sources on one layer of the map, all you have to do is remove the "inside" magma from that layer to claim it. The easiest way to block the magma sources is to cast obsidian dikes. The plan is just to cast walls around the top layer sources, pump out the inside magma, then repeat.
If it really were that easy, there wouldn't be much point in writing this guide. If you've had much experience with the magma sea, you've probably already forseen the catch: you can't cast obsidian on magma flow tiles which floor the bottom of the magma sea, nor can you use a cave-in to drop a wall in place. How are you supposed to block the bottom-level magma sources when you can't dam it up? The answer is that by installing enough drains in the bottom of the magma sea and by dumping in enough water from the top, you can crowd out enough of the magma to do some construction on the magma sea floor. More on this later--I don't want to spoil the surprise.
Getting through the upper levels takes some patience, but it's really not too hardcore. You can make it to the next-to-bottom layer with nothing but buckets and a single pump stack, if you like. I did. Chances are, you'll expose a couple swaths of magma flow you can use for an extra-dwarfy throne room or something if you don't want to go hardcore and settle the bottom layer. If you're experienced with magma and obsidian, you can just skim this section. Maybe read the HFS-related part.
You want to surround the sources with obsidian, and you do that by pouring water around it. You could do this by draining water from the caverns onto the magma, but I chose to do it with buckets. To do it my way, just channel out a hole in the shape of the wall you want to build TWO layers above the magma sea (if you don't you'll just get steam for some reason), then designate a separate pond (i-p-P-f) for each square in the wall.
The first picture shows the hole carved out for pond designations (center-top), the second shows the obsidian wall created two levels down.
Note that the procedure for the middle layers is exactly the same as it is for the top. You won't be able to place your mid-level obsidian walls directly beneath the top-level one, so you'll probably end up building a sort of terraced wall.
Now that all the sources are walled off, you can either pump out the magma, cast it all into obsidian and mine it out, or you can, well, it's inside the spoiler tag below. The wiki explains pump stacks quite well, so I'll just add that you'll save yourself some work later on if you can find a place to pump magma out of the bottom layer from the start.
Turning the magma to obsidian and mining it out isn't something I did, but it's a reasonable choice if you want to harvest some obsidian while you're at it. Of course, if you choose this method you'd want to skip the bucket-and-pond process I described above.
There's a theoretical fourth option, too. You could atom-smash the magma, that is, crush it out of existence with a drawbridge. I doubt this would be terribly effective, but I mention it because it might be of use when you tackle the bottom layer if you aren't ready or willing to deal with the HFS.
Once you've defeated the first wave of demons, you can enter hell and dig stairs upward toward the magma sea. Beware wandering demons, of course. You can't penetrate the magma flow tiles this way, but you can dig into the normal rock walls you find at the bottom layer. This will let you install a drain leading to the nearest eerie glowing pit. Make sure you install a lever-linked hatch or bridge or something so you can shut off the drain if you need to. Later on, securing the bottom layer of the sea will be much more difficult if you don't use hell drains. Warning: you are very likely to lose dwarves when you puncture the bottom of the magma sea. Placing the drain hatch as close to the hole in the sea as possible will help maximize their chances.
Various drains are circled in white. All are down stairs cut into diorite rock near the magma flow, even the ones that appear separate from the diorite walls. There happened to be a couple isolated pillars on those spots.
The magma sea floor is rarely level, so chances are you'll find that the sea floor at some magma sources is higher than at others. This is good. You can totally wall off these "hill" sources by casting a wall around the "hill." Hopefully this picture will clear up what I mean:
The magma you see here is sitting on top of magma flow tiles. The wall around is touching the edge of that magma flow, but directly beneath the wall is open space. The "real" bottom layer is below the open space.
This is where the real work begins. You can't directly cast a wall to seal off the magma sources (if you try, the magma and water both turn to steam), and you can't cave-in one, because the magma flow will eat it. To make any headway at all, you'll have to dump so much water into the magma sea that you crowd out a large portion of the magma. Aggressively draining or pumping out the magma (see "Clearing out the magma" above) will make this task more doable. Unfortunately, I lost access to the pictures I took while doing this myself.
On top of the magma flow tiles. water and magma do not form obsidian. Instead, they annihilate each other, leaving only a cloud of steam. If you can pour enough water into the magma fast enough, you can annihilate some magma and fill the empty space with water before more magma can fill that space. The method is pretty straightforward: dig a vertical shaft above the magma sea, install a bridge/floodgate/whatever as a shutoff valve, and connect it to your water source. Still, it's not easy to get the volume you need. A pressurized blast of water, such as you'll get by poking a hole in the bottom of a multi-z-level cavern lake, will help you gain a foothold on the magma sea floor. You'll need a continuous source of water to maintain that foothold, though, and one cavern may not give you enough. You'll probably need several sources of water routed to about the same place in the magma sea to make this work. An aquifer is very helpful, but I doubt it's a requirement.
This is a bit difficult to explain without access to my original pictures, but I'll do my best. You've probably noticed that most magma sources span multiple z-levels. That is, magma tends to flow in from the same part of the side of the map on all levels of the magma sea. While you were working on the middle layers, the sealed-off sources above you didn't matter because the only place the upper-source magma could go was down into layers already filled with magma. Now that you're working on the bottom layer, though, they begin to contribute again. It is very helpful to isolate these upper layers from the bottom layer so you won't have to drain so much magma. Once your drainage system really gets going, you'll hopefully notice that magma levels behind some of the top level obsidian walls begin to drop. As soon as the magma level temporarily hits zero on that level, you can designate a bridge there. It doesn't matter how much magma is there during the build--once it's designated, you can finish it. Hopefully this picture will clear things up:
The bit on the map's edge that looks like magma flow tiles, circled in blue, is actually a bridge covered in magma. I used the doors, circled in green, to gain access without breaking containment. As you can see, any magma created on this level has no place to fall down to the level below. This process will drastically cut the magma flowing into the map, but keep in mind you need to drain quite a bit of it in the first place before this is even possible.
So, by now you should have a pool of water forming somewhere in the magma sea near one of the sources. At the border between water and magma, there should be a wall of steam where the two continuously annihilate one another. Believe it or not, it's actually possible to walk a dwarf up to that line and build a wall there by hand. In fact, I did that in part of my own map. You will lose a ton of dwarves to melted toes if you try this (seriously, they bleed more than two severed feet), and it's an unreliable method at best. Fortunately, I found a better way. One level above the water-magma line, trace out the path you want your wall to take with down stairs. Next, build and up stairs directly beneath each down stairs. You will probably have to do these one or two at a time as each square is temporarily free of water and magma. Surprisingly, the dwarves can finish the up stairs while there is a little bit of magma on the tile, so you probably won't get much cancellation spam. The key to all this is that obsidian can be cast on these up stairs, and in fact it will probably happen automatically.
Above you see the up/down stairs I used as scaffolding to build up-stairs between the water and magma. Below you see the obsidian wall created on top of those stairs. Incidentally, the wall created is a tiny bit buggy. It does not create an obsidian floor above it like it should, instead leaving open space. If you want a floor there, you can always build one yourself.
Once you've sealed off every magma source, it should be a trivial matter to drain the water. You're done. Congratulations!
I discovered a new technique that makes this whole process MUCH easier. It turns out that, one you've emptied everything but the bottom layer, it is possible to cast obsidian on the sea floor using only buckets of water and stairs. Rather than redo the whole thing from scratch, I made a little demonstration, casting a single block of obsidian. The pictures I took are probably overkill, but whatever, screenshots are easy.
Use these steps INSTEAD of the steps from "Part II: The Bottom Layer."
First, you'll need to build some down stairs directly above the tiles where you want to cast obsidian. You'll be dumping water on these stairs from one z-level up, so now is the time to build a walkway up there, too. After all the construction is done, go ahead and setup up pond zones on that upper walkway so the dwarves will drop the water on the down stairs you just built.
For my little demonstration, I built one down stair next to the central column, and an up stair next to it. The dwarves climb the up stair and dump the water from one level up.
This step needs to be executed with great precision. When your dwarf dumps water into the magma sea, the water annihilates one square of magma, and you've got a VERY brief window where the floor of the magma sea is exposed before more magma flows into the vacuum. During this window (like 3-4 ticks in length), you can designate an up stair to be built on that spot. I highly recommend going tick-by-tick with '.' so you don't miss the window.
Once you've designated the stairs to be built, the dwarves will finish them, even if the tile is totally filled with magma.
Use the pond to dump one more bucket of water, and it will cast an obsidian wall over the up stair you just built. Just repeat this process to wall off the magma sources on the map's edge, then pump/drain the rest of the magma.
I've finished the outer structure of the sub-magma arcology. I said I was doing a subfort earlier, but I went ahead and built it with the capacity to hold all ~110 dwarves. I've got 74 common bedrooms plus space for a few noble bedrooms. Most of the space in the colony is still unallocated, so I'll post another update once I've furnished more of it. I could do some detail shots at that time, if any of you would like to see them.
Pictures posted below show the colony from the bottom up. The little rooms in the top left are the bedrooms. They are arranged into mini-towers accessible by a maze-like walkway on the top level. The ring-shaped bit nearby is a water source hooked up to the aquifer. Magma will fill the inside of the ring and serve to power magma forges. The dining room should be pretty obvious near the center of the picture. The irregularly shaped rooms are the remnants of the adamantine spires. They will be isolated from the colony once construction is finished. In the bottom left, fourth layer, you may notice a minecart track. That is where the entrance will go. I plan to force dwarves to ride a cart which skips over the magma to enter the colony, but that part hasn't been built yet.
So, what do you think? Any suggestions?
Here is the entrance to the colony. A dwarf who wants to enter must ride a minecart over the magma and through the fortification (the wall-like thing in the middle of the tunnel). The dark triangles are impulse ramps. It's not at all obvious how the admittedly convoluted dwarven system works from the picture, so let me explain it. The dwarf is propelled forward by these ramps, makes it one tile past the side track on the opposite side of the gap, the dwarf exits the cart as it has temporarily stopped moving, then the cart it propelled backward and onto the side track, which takes the cart to the intended stop.
You sharp-eyed readers may have caught a strange feature of this two-way cart system: it's not symmetrical. The side track is closer to the final destination on the south side than it is on the north side. This is not due to carelessness. It needs to be built this way because, having verified that the slightly off-center fortification has no effect on the minecart's path, I have discovered that the minecart travels faster going south than it does going north. I do not know whether this is a quirk of impulse ramp physics or it's a strange dwarven preference for south. Is this known behavior, or does Science need to be done?
In the lower left is the dining room, complete with steel tables and chairs and the following artifacts: an adamantine animal trap, an adamantine statue, two other statues, and a weapon trap including a mechanism and adamantine giant axe blade.
In the lower right is a farm with attendant workshops.
In the upper right are some of the bottom level bedrooms. Each room has a nether-cap bed (I figured it must get a little toasty under the magma, so a perma-chilled bed would be nice), a steel cabinet, and two clear glass coffins, because each bedroom doubles as a tomb for its occupants. Surprisingly, this generates a ton of happy thoughts.
In the upper left is the underside of the workshop level. The inner ring of magma powers the forges. The water is piped in from the aquifer. You can't muddy the magma flow, so it's always clean.
As you can probably tell, this is just one level above the previous picture. The magma forges and smelters are in the upper left, the bedrooms are on the upper right, and there are food and drink stockpiles in an alcove above the dining hall in the lower left.
On the right you see a dome with two stockpiles. The right stockpile is just metal bars, but the one on the left is all artifact finished goods. Figurines, musical instruments, and the like. This my way of putting them on display. There are about ten more on the next level up, too.
The real point of interest is actually the dividing line between two stockpiles. See the crooked line of grey squares with white dots? That's "open space." But directly below is a cast obsidian wall. This weird little glitch occurred when I built stairs on the magma sea floor and cast obsidian on top of them.
The two left "petals" of the clover-shaped building are the offices, currently unassigned, and right petal is a jail. They're all a little bare-bones at this point.
I stupidly forgot to implement an effective pitting system, so I'll have to release enemies with lever-linked cages. Marksdwarves can stand on a 2nd-floor walkway and shoot at resurrected enemies below.
At the top are some of the rocs I'm trying to breed. I managed to get some hatchlings, but the whole process is extremely unreliable since most of the eggs never hatch.
On the lower left is the first level of the Temple to Armok, with a blood sacrifice of ~30 child animals in progress, plus a few dwarf children (Don't worry, I didn't let them die). The room is floored with steel spikes and the statues are of enemies dying in particularly nasty ways, such as being impaled on spikes.
The hospital is at the top. It's pretty mundane, except my dwarves went nuts and overshot the target cloth stock by several million units.
Bottom left is the second level of the Temple to Armok. It's filled with skulls. Totems, to be precise.
I got Overseer running with WINE, so I took a few pictures before releasing the magma. They're not terribly enlightening, but I think they look kinda cool.
These are some pictures of another mega project I was working on while finishing up the colony entrance and refilling the magma sea. It's 55 tiles in diameter and 15 levels high. It's made almost entirely of copper (probably about 1500 bars), plus a few hundred bars of salvaged bismuth bronze and about 30 imported native platinum blocks. Not really related to the colony, but I wanted to share and wasn't sure it merited it's own thread.
In the background you can see two other major constructions. One is a cast obsidian lava cistern which extends all the way down to the magma sea. The other is the surface portion of the main fort, build around a 31-tile (I think) diameter pit which extends to just above the magma sea. Granted, the magma sea is only about 30 levels deep on this map.
Update (July 29th): I've uploaded the map to the DF Map Archive:
http://mkv25.net/dfma/map-11838Update (October 13th): I've updated the map on the DF Map Archive:
http://mkv25.net/dfma/map-11905-heartmineUpdate (December 22nd): Another update to DF Map Archive:
http://mkv25.net/dfma/map-11952-heartmine
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Topic: The Last Frontier: Draining the Magma Sea (even the bottom) [Colony Complete!] (Read 68334 times)