A few days ago I told a friend my NEXT fortress would be amazing, what I meant was, the one after that.
So far, I have managed to fail at several drowning trap entrance defences. I think I have it figured out now and this one...this one will work great.
The basic goal has been a low straight hallway that can be flooded. One end is "inside" and goes up into the main fortress the other goes up to the surface as an entrance. Simple right? To make this easier, I have been selecting sites with rivers. I like my current one as it has a river at the bottom of a steep canyon. Its nice.
Attempt 1:
Being unaware of wagon issues, I used stairs, straight down, and straight back up. This was the first time that my military was vaguely effective and kept ambushes at bay. Too effective almost, as none made it to my trap until the first siege.
Water was connected to the inside stairwell, about 2 levels up, with a couple of levels of reservoir. It started well, at about 1/2-2/3 of the way down the hallway, my dwarfs pulled the lever, and water pushed them back, all the way to the other side and stuck the invaders there....but wasn't enough to drown them.... quickly the flow stopped, the water wasn't high enough, and they crossed the hallway, and slaughtered everyone inside.
As this was going on, the mayor, who was building a wall inside the new, larger, aqueduct, walled herself in. She was the final survivor, and eventually died.
I attempted to reclaim the fort, breaking in from the top. Things went well mostly, if a lot of cleanup, until a siege came and a couple of peaceful goblins went hostile. Before that happened I did manage to fix my water system by making it larger, didn't help when the threat was inside.
Attempt 2:
Much better. More water, more pressure. When I opened the floodgates, the hallway filled quickly and completely. All was set. The key has been to keep the lower levels of the pipe small and discharging straight into the hallway, and put more water above in higher levels to keep the pressure up as long as possible. Several dwarves were injured in cave-ins as they stupidly mined and channelled out the reservoir.
By the time it was finished one of the miners was so crippled, that I never spotted him out of bed again.
The problem this time was not the drowning chamber: I learned about cage traps. I made a small landing a few flights up from the chamber and put a first line of defensive cage traps there. They were in place mostly to deal with invasions before the drowning mechanism was complete.
So in this case, the goblins came in, their leader got caught in a cage, and the first ambush to come in turned into a siege that my dwarves were not prepared to break. Then, while we were still recovering from that, a real seige came and did the same thing. Unfortunately some farmers died in the first initial attack and this went unnoticed as I tried to figure out how to deal with the goblins, so by the time they left everyone was running outside to trap animals and vermin.
We had no chance when the siege came, everyone died miserably, mostly of starvation. Our front door was wide open, as everybody was in too much of a panic to pull the lever. The goblins never moved in, even as my injured miner died in bed leaving the final citizen, a dwarven child to go insane and die.
I really hate goblins. They are going to pay for this.
Attempt 3: (current project)
The bottom of my current drowning reservoir looks like a cone. It isn't complete yet but the drowning stage is set somewhat like this:
cut out Inside
-------------------*----*--^^^^ |-----|
| ^| * * F |
| ^| A * B * |-----|
| ^| * * F |
| ^|------- ----------------------|
| | A = Entrance
| | B = Long hallway cut out for brevity
---------------| F = Flood gate ^ = up ramp
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The path around is a bit wider actually but this is the shape. Note the hook at A, my intention is to channel out that area so that all pathing moves away from the channelled area, but water should push anyone in B into the pit; which will be a room with cage traps and drainage. (connected to another flood gate for control)
This time, I will place my first line of cage traps in the "B" area, towards the middle to hopefully make use of this "gaurd the leader" behaviour to trap them, rather than protect them.
That is the plan, so far so good. If this works, I will be building some goblin target practice chambers, and possibly some places for goblin sacrifice. Payback is coming.
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Topic: Adventures in drowning traps (Read 682 times)