40d:Hatch cover

A Hatch cover is a circular covering for a hole in the ground, which is effectively a vertical door. It is classed as furniture and can be built from either rock, wood, metal or glass. When closed, hatches have the symbol ç, and when open they look like empty space.

Hatch settings

There are three options one can specify on a door from the q menu:

• l Forbid/Permit Passage
  • A hatch set to Forbidden is impassable to any dwarves in the game. A hatch cannot be set Forbidden if it is open. Invading thieves may lock-pick and bypass a Forbidden hatch.
• o Keep Tightly Closed/Make Pet-Passable
  • A hatch that is pet-passable allows through traffic of pets. A pet can still pass through a hatch that is tightly closed if it does so while it is being held open by an object or dwarf.
• s Set as Internal/External
  • A hatch set to external functions as a floor? when defining boundaries of a room such as a bedroom. A hatch set to internal allows the room boundaries to pour over.

Building Hatches

After constructing a hatch at any of the above workshops, they must be "built" (placed) like all other furniture. Hatches can be built on any free floor tile, over empty space, or on top of down-staircases (or up/down staircases, or even up-staircases, although that last option won't do anything useful). Hatches cannot be placed on the same tile as most other constructions, including all furniture and traps. However, they can be placed on "rough-hewn wall" tiles, which somehow leaves the wall intact!

To be used effectively, a hatch should either be placed above a downstair (or in an up/down stair) where, like a door, it will impede liquid flow while still allowing access; or alternatively it can be linked up to a lever (and probably placed above a channel, or lava, or below a river etc), which when pulled will temporarily open the hatch, allowing whatever is above to fall down below.

Like grates, hatches placed on top of floor tiles are purely decorative. Placing a hatch cover does not automatically dig out anything under the hatch.

Water which has a hatch on top of it can still be used as a water source and for fishing.

Hatches over empty space can be safely walked on and even driven over by caravans (They do need to be next to a wall or floor for support, however, but they can't even be built if that condition isn't met - and supports on the level below don't do any good).