After building a flood trap, not for the purpose of drowning invaders but to displace them into a confined area where I can later make use of them, I've come to wonder how these flow mechanics can be used in more advanced designs.
Here are a few ideas I've had. I'd like to see some examples of where these concepts have been used in existing forts, if they do indeed work.
Flow Conveyor, Side View. Move an item or creature a long distance from right to left, eventually settling on top of the floor grate. Water is pumped up on the right side and flows left, intended to move items with it. A floor grate on the left catches items while allowing water to fall below and eventually return to the pump. Water level needs to be controlled to ensure flow is occurring.
Key: W: Wall, _: Channel, G: Floor Grate, P: Pump, ~: Flowing Water
WG~~~~~~~~~~~~~~~~~~~~~~~PP_W
W~~~~~~~~~~~~~~~~~~~~~~~~~~~W
Flow Delivery System, Side View. A controlled method for dropping an item down a pit without tedious management using Dump and Activity Zones. The idea is your dwarves automatically fill the stockpile with whatever you want, and then you can open the floor hatch and inner floodgate pushing items out of the stockpile and down the (open) floor hatch. Items are caught below by a grate while water drains away.
Key: W: Wall, _: Channel, H: Floor Hatch, G: Floor Grate, X: Floodgate, S: Stockpile, ~: Still Water
WHSX~~X~~water source~~
WG destination W
drain
Designs are more conceptual than foolproof schematics; they would likely need modifications for application in a fortress. Are these concepts sound? Are the effects of flow controllable enough for these kinds of things to work? I'd love to see some examples if they've been done before.