Water Tank (Railcraft)

The Water Tank is a multiblock structure from Railcraft used to store and collect water. This multiblock will passively collect water depending on the environment it is built in (see below). The tank can hold 400 buckets of water at one time.

Construction
The Water Tank is built out of 26 Water Tank Siding blocks, meaning that five sets of six will need to be crafted to build the entire structure. They cannot be built directly next to each other, there must be at least one block in between. They are built in a 3x3x3 with a hollow center out of Water Tank Sidings.

Water
To determine the average amount of water condensed by the Water Tank (as of Railcraft 9.7.0.0, Minecraft 1.7.10), follow these steps:

†Weather is considered on or off. Arid biomes will not exhibit weather. Rain biomes (the default) will rain. Snowy biomes will exhibit snow.
 * 1) Get the biome's "Rainfall Property" from the table below. The central column of your structure is the one determining what biome will be used for the calculation.
 * 2) If none of the blocks in the structure can see the sky, divide this number by 2 and skip to step five.
 * 3) If at least one of the blocks in the structure can see the sky and it is raining†, multiply this number by 3.
 * 4) If at least one of the blocks in the structure can see the sky and it is snowing†, divide this number by 2.
 * 5) Round the number down.
 * 6) The water tank will produce, on average, this number of millibuckets every eight ticks (x/8 mB per tick).