Prior to the use of steam, water balance pits were sunk using the weight of a tank of water fixed under the pit cage, to take the empty cage and tram to the pit bottom, at the same time hoisting the full tram to the surface. This was done by filling the tank at the top of the pit, and draining it at the bottom, when the full tank outweighed the empty one. These water balances were normally seen only on a hillside, because the pit bottom had to be at sufficient height above the valley bottom for draining. On this particular wheel, it will be seen that there was no brake band. Braking was achieved by means of a 'Hydraulic Retarder', this device can be seen at the bottom of the wheel, looking like a steam engine. The small cylinder was used to pump water, and Retarding or Braking was achieved by restricting the flow of water pumped.
Blaendare Water Balance Wheel 1832
Balance wheels were the first attempt to use mechanical power rather than horses or manual muscle power to raise coal. There were several advantages to this system: As it used no coal or wood fire to generate steam, it was clean and non-polluting, it's only by-product being water, and compared with steam, it was also virtually silent.
