|This article is about the current version of DF.|
|Part of a number of articles on|
|Aqueduct • Archery tower • Atom smasher • Danger room • Dam • Garbage dump • Mass pit • Moat • Pit trap • Reservoir• Sally port • Swimming pool • Tower • Tree farm|
|Drowning chamber • Magma piston • Obsidian farm • Pump stack • Silk farm • Water reactor|
An archery tower is a common and useful piece of defense design. It is basically a pillbox in the form of a tower, useful for spotting ambushes before they get close enough to do serious damage and for allowing your marksdwarves to fire on enemy goblins "in the field" without exposing themselves. The premise is simple: dig out an internal walkway to the surface and wall it off so that enemies cannot use it to enter your base. Curtain wall it with fortifications and you have a ready piece of defense engineering; to keep flyers out, roof the structure (or put a bridge over it if you want to be able to selectively allow them in for whatever reason).
NOTE: It is better to construct walls and then carve fortifications into them, than to construct fortifications. The reason for this is that constructed fortifications do not provide an implicit floor on the layer above them, but walls do. Walls cannot be constructed without access from one of the four compass directions. Because of this, if you were to construct fortifications, when you progress to the level above, you would need to build a walkable path to the corner tiles. This path would need to be deconstructed before the wall or fortification could be built. Once deconstructed, the building material will drop onto the tile below with the fortification, trapping it until the fortification is deconstructed.
As discussed step-by-step in the article on mega construction, this particular design is about as basic as it gets. As shown, it assumes entry from an underground tunnel, but a door or drawbridge (with moat!?) could easily be added, or even access via a protected sky-bridge.
This can hold 3 archers/side, and has the potential to be as many "archer levels" tall as you wish. The fortification in the center of the building prevents low-level archers from standing there (since they are unable to fire through any non-adjacent fortifications) while allowing high-level archers a full 360 field of fire. Including a bed allows the room to be designated as a barracks, so your marksdwarves can train while serving as lookouts and defending your fortress. Adding raising bridges outside the fortifications will allow you to protect your marksdwarves when an elite enemy archer threatens. Building a secure "roof" will require a temporary exterior stairway. Alternately you can build stairs at the Archer Level in place of a non-corner wall to allow roof access, then once the roof is completed remove the stairs, put a wall in its place and finally carve fortifications into it. Remember to use the "corners first" technique when necessary. (See 40d:Mega_construction#Towers.)
All told, for a simple 1 archer-level tower, this takes just over 50 stones or blocks (plus 25/extra archer level).
This design can be further elaborated upon by expanding it, adding further floors, room, and so on. It is possible to build a whole barracks and above-ground military complex, or go even more extreme and turn your fortress into one enormous tower. For more ideas on how to put these together into a functional defensive grid, see defense guide and security design.
With the advent of climbing monsters in recent releases, this basic design can be elaborated slightly to prevent climbers:
This is conceptually identical to the first design, but adds two levels of overhang to prevent climbers. Note that fortifications can be built on walls, but not floors, and floors can be built on fortifications (for the roof).