40d:Water wheel

Water wheel

b-M-w
═ ═ ═ X X X
Construction
Materials	Jobs
3 Wood	Architecture Carpenter
Power
Needs 10 power. Generates 100 power. Net gain of 90 power.

A water wheel is a machine component that provides power via water flow. To build a water wheel, select build menu and choose Machine components. It requires 3 wood and generates 90 net power, which can be used for operating a pump or mill. You can use axles and gears to access the power produced by a water wheel, or connect machinery like a pump or millstone directly.

Waterwheels have quality levels for both design and building. These can be checked from the room screen by moving to the entry and pressing enter.

For a basic overview of how the different machine parts work and work together, see machinery.

Construction

The architecture and carpentry labor are needed for the construction.

A water wheel occupies 3 adjacent tiles (N-S or E-W axis, no diagonals).

Although you can build a stable water wheel on solid ground, this isn't going to do you any good. For this reason, water wheels are almost exclusively built in a hanging state with gaps in the floor below. To do this the water wheel must be attached to a nearby machine component. In order to function, a water wheel must attach to other pre-existing machine components only on either side of its center tile.

Power will be sometimes generated once one channel tile under the water wheel is filled with water at a depth of four or greater if there also is a water flow in one of the three tiles beneath it (we need more info in the article on what constitutes waterflow). The easiest way to achieve this is to place the water wheel in a river, but also a brook or channel works if done right (read below). Having two floor tiles and one channel tile below the wheel will only sometimes work, even if that one tile fulfills the above conditions.

You can transport the power wherever it is needed via horizontal and vertical axles and gear assemblies. It is possible to support a waterwheel by building its center next to a preexisting water wheel's center.

Brook

Intuitively one would place a water wheel in a river, but they can also be powered if placed over brook tiles, but only if you first dig through the surface of the brook. Dig a channel three tiles long, right on the brook. The water wheel will sit above this channel.

Channels

It is possible to power a water wheel in a channel if it is connected to a river or brook (read as: water that has flow. Further details needed.) A channel connected to a murky pool will not suffice, no matter what water movement is present in the channel.

Any direct non-diagonal connection (see water pressure) to a river or brook that has flow (some do not) will power a waterwheel, even if it's a dead end. A floodgate in the channel will not block this flow either.

Designs

Basic watermill design

#	+	+	+	+	~	+
#	+	+	+	+	~	+
#	O	+	+	+	W	+
#	*	═	═	═	W	+
#	+	+	+	+	W	+
#	+	+	+	+	~	+
#	+	+	+	+	~	+

Dual watermill design

#	+	+	+	+	~	~
#	+	+	+	+	~	~
#	O	+	+	+	W	W
#	*	═	═	═	W	W
#	+	+	+	+	W	W
#	+	+	+	+	~	~
#	+	+	+	+	~	~

This is by no means the limit of water power from one location, depending on the width of your river/brook/channel you can stack many waterwheels side-by-side (really big assembles will need to be artificial as there's a limit to how wide the game created water flows get). Just remember to make sure there's a support structure in place before you place the next wheel.

Perpetual motion

Due to the relatively low power draw of a screw pump, a self-powering assembly can be made with a water wheel that still leaves plenty of excess power for other uses. This is an exploit (violating basics principles of physics), and possibly a bug, but this is also Dwarf Fortress, so...

To get it working, you must start the pump manually.*

(* Exceptions are aquifers, which can sometimes have naturally occurring flow. This is sometimes a good thing, because then a wheel simply works by itself - or a bad thing, if, for example, you want the wheel to not provide any power while you build a pump adjacent to it. It's not clear what causes an aquifer to have flow and then keep it - it's difficult to replicate reliably, and can be lost with additional channeling, so designs will have to be adapted if such are found.)

It is good to have a ready source of water to refill the machine, as water tends to escape and evaporate, and once the water falls below a certain level, the machine stops. Below an earlier level, the power supply becomes intermittent.

Key:

║ ═ ╝ ╚ ╔ ╗ ╣ ╠ ╩ ╦ = Wall
+ = Floor
W = Water Wheel
* = Gear Assembly
═ = Axle E/W
║ = Axle N/S
XX = Pump from west
_ = Channel
X = Closed Water Source Opening

*REMEMBER TO BUILD AN ADJACENT PUMP, HORIZONTAL AXLE OR GEAR ASSEMBLY BEFORE THE WATER WHEEL*

Design #1

Upper Level	Lower Level
█ █ █ ╔ ═ ╗ █ █ █ ╔ ╝ + ╚ ╗ █ █ ║ ▼ + + ║ █ █ ╠ ═ ╗ + ║ █ █ ║ X ║ + ║ █ █ ╠ ═ ╝ + ║ ╔ ═ ╝ + + + ║ ║ + X X _ ╔ ╝ ║ W O ║ ╔ ╝ █ ║ W ═ * ║ █ █ ║ W ╔ ═ ╝ █ █ ╚ ═ ╝ █ █ █ █ █ █ █ █ █ █ █	█ █ █ █ █ █ █ █ █ ╔ ═ ╗ █ █ █ █ ║ ▲ ║ █ █ █ █ ╠ ═ ╣ █ █ █ █ ║ X ║ █ █ █ █ ║ + ║ █ █ ╔ ═ ╝ + ╚ ╗ █ ║ + + + + ║ █ ║ + ╔ ╗ + ║ █ ║ + ║ ║ + ║ █ ║ + ╚ ╝ + ║ █ ║ + + + + ║ █ ╚ ═ ═ ═ ═ ╝ █

XX = Pumps from east

Design #2

This uses a simple oval as a waterway. Changes to the design to fill that may be needed. Expect spillage from the pump outlet.

█	╔	═	╗	█	█	█
╔	╝	▲	╚	═	═	╗
║	+	+	+	+	+	║
║	+	≈	≈	≈	+	║
║	+	W	+	X	+	║
║	+	W	═	X	+	║
║	+	W	+	≈	+	║
║	+	≈	≈	≈	+	║
║	+	+	+	+	+	║
╚	═	═	═	═	═	╝

X
X = Pump from south

Design #3

Dwarven Water Reactor

This compact design, once started, cannot be stopped without complete de-construction of all components, since the pump is directly linked to both wheels - deconstructing one wheel will cause a flood (and almost immediately cancel any job order to deconstruct the other components), and deconstructing the pump will cause both wheels to collapse (unless they are attached to machinery outside them, not shown). Power is routed up from the pump or off to the side from a wheel, where a gear assembly can be placed early in the power train, linked to a lever, to disconnect the power at that point.

The design below produces 170 surplus power (less additional power train), almost twice that of the above designs in less than half the space. Expanded versions can produce more power, but should be planned in advance unless you're willing to tear it all down to change the configuration. A second reactor, then connected to the power train, might be better.

Upper Level	Lower Level
╔ ═ ╦ ═ ╗ ║ ≈ ║ ≈ ║ ║ ≈ ║ ≈ ║ ║ ≈ O ≈ ║ ╚ ╗ ≈ ╔ ╝ █ ╚ ═ ╝ █	╔ ═ ═ ═ ╗ ║ W + W ║ ╝ W X W ╚ + W X W + + + ≈ + + + + + + +

X
X = Pumps from south

Dig the V-shaped channel and fill it with water (either from an outside source or by designating it as a pond). Meanwhile, construct the pump, pumping from the South. Construct the two water wheels. Start the pump manually ( q, Enter ) - if there is enough water*, the "reactor" will start immediately and the pump operator will leave. The water from the north end of the pump will spill over the top-most floor tile, filling that to 7/7 and the two tiles east and west of it to ~5/7, but will not overflow back past the water wheel to the walkway area. Note that for the upper level, no southern walls are shown as none are needed.

(* Have not determined the minimum depth needed. For better flow, you might try a "U-shaped" channel, rather than V-shaped, but that requires 2 more tiles to be filled with water.)

Note: If created in an aquifer, there is a chance that the channeled tiles will have a natural water flow - this will cause the pump to start the moment the first wheel is finished, flooding the work area for the second.