New Tainter Gate Hoist

A new 23-ton tainter gate hoist consists of a ratchet wheel driven by a pawl on a lever, which, in turn, is driven by a piston in a 2,000 psi hydraulic cylinder. A second pawl holds the ratchet wheel, as required. A cable drum is connected to the ratchet wheel. Two cables carry the load of the tainter gate over a set of sheaves to the drum. The mechanism was contained in a steel box 5 ft 3 in. square by 2 ft 7 in. deep, mounted on the side of a spillway pier. Each hoist contains an electrically driven hydraulic pump. Hoists are controlled from a remote control board in which the position of the group of gates is indicated by one Selsyn receiver. In one stroke of the piston, the gates move 4 in. up or down. All gates readily can be set to a uniform opening. The apparatus is well-adapted to spillways on soft foundations in which all gates or groups of gates must be opened in unison. Each 4 in. turn of the ratchet wheel results in a definite discharge, permitting close control of water releases.