Well it's good some info is confirmed...
Now we just need to know how quickly does a dwarf pull a lever and how fast water flows. Maybe we should play it safe and use floodgates? Why do we have the 2nd floor down there anyways? I remember that it would fall through the upper floor but how are we going to dig it out if we have no access to it? If we do then that would leave it vulnerable to building destroyers and flying creatures. So might as well only have 1 floor. I doubt we will have any practical use for it anyways.
Yes, use floodgates. They'll prevent jams. I'll add them to the plan.
The purpose of the otherwise empty second level is that the floor will prevent creatures from coming up through it, but not block the cave-in from killing the stuff below it. Also, it allows the cave-in to target the entire hallway - if the second level wasn't there, the hallway would need to be three tiles wide or the obsidian wouldn't fall.
Fun stuff:
1.We locked to expedition leader on the roof of the apartments and she got pretty hungry and thirsty.
2. A groundhog dodged into the volcano.
EDIT: Basically, the "proper" way to run it is:
Close floodgates
Activate pumps
Read "crushed under the collapsing ceiling" messages
Deactivate pumps (You'll probably be able to just queue the lever to be pulled twice)
Open floodgates to reload
Dig out tunnel, leaving obsidian floor above intact.EDIT2: I'll test it out and post a video on the DFMA.
EDIT3: I'll upload the video in a while.
EDIT4: AARGH, SDL. Brb, downloading legacy and re-recording.
EDIT5:
http://mkv25.net/dfma/movie-2299-cave-inguntestIt works... mostly. For some reason, the third tile from the top didn't obsidianize, although the water and magma were consumed. This also happened on the first test, except with the second tile. I don't know why. It's okay though - anything that could exploit that flaw would have to survive the full cave-in dusting action.The structure was minimalistic - I didn't bother with pumping the liquids into the chambers (thank you dfliquids) and the floodgates were just for show. The doors were simply for construction access, and should be replaced with walls in the final assembly.
EDIT6: Didn't even notice this:
Oh and where can I drain the magma from the volcano to make the glass entry? I can't alter the edges of the map so... Yeah... Wait... I could just drain some into the yin-yang sing but that still leaves a bunch... Any ideas?
Atom smasher.