My favorite embark tends to be on a glacier with a towering volcano. And I recently found something fascinating in an embark that was a bit different from my usual embarks.
The volcanoes often have some ice walls on the first level. Obviously, it's not hard to melt these walls by putting magma around them. Putting magma below or to the side doesn't really work by itself (as in either of those cases, unless the square with the ice has been dug out and floored before, the water will merge with the magma to form obsidian), so it's best to spread magma over top of the ice. If you do this on top of an ice wall next to an open square, the water will then spread - and if magma isn't also on top of the new square, and that square is outside, that new square will gain a new ice wall. And due to the fluid mechanics (specifically, because ice always melts to 7 water), this will spread exactly one square beyond the extent you allow the magma to spread. In other words, a self-constructing ice wall.
In my case, I'd built a rectangle of floors 5 wide surrounded by constructed walls at z=+1; this resulted in a rectangle of water 5 wide surrounded by ice walls at z=0. The water was essentially self-refilling due to irregular freeze/melt cycles (even with the magma constantly on top of it - I wasn't even manipulating the magma after getting it out of the volcano), and digging into the ice walls only resulted in the ice wall reforming (and, once, killing the miner - I'm guessing the miner moved in the wrong direction). I haven't tested how various construction like bridges on either level will affect it, or the possibility of draining the water.
I have a few thoughts as to how this could be used in case of sieges, wagon safety, and a few other things, so I was wondering: has this been discovered before and/or put to dorfy uses? Or do you guys have any thoughts on how to use it for !!FUN!!?
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Topic: Self-constructing (kinda) ice walls (Read 931 times)