by the dimensions of the turbine and generator. However, as this level is below the maximum possible flood level estimated at the time of the design to be at it was the powerhouse and the workshop were made watertight up to this level. As a result, the windows are set high and the doors are at the level. Open to the machine hall but raised approximately three metres above the main floor at the western end of the powerhouse is the unloading bay underneath of which is the 400 V switchgear at main floor level and below them is the auxiliary generating sets on the generator floor. The lowest level is the drainage gallery at which runs the whole length of the powerhouse and gives access to the draft tubes. The generator transformers are located outdoors on a platform above the tailrace at . Generating units Each spillway drives a Francis turbine supplied by Dominion Engineering of Canada. The turbines have a nominal speed of 136.4 rpm with a guaranteed maximum runaway speed of 252 rpm. The turbines have a rated output of 56,000 hp at a net head of 148 ft (13.7 m), which consume of water at full load. The runners weigh 28 tons and have a diameter of 12 ft 10 inches (1.2 m). The speed of the each turbine is controlled by a Woodward supplied governor located on the generator floor. The generating unit are located apart between centres. Each turbine is directly connected to a dedicated to a 44 pole 11 kV synchronous generator supplied by British Thomson-Houston (BTH). Each generator has an output of 44.44 MVA at a power factor of 0.9 and a total weight of 362 tons with the rotor weighing185 tons. The generators are each enclosed in thick-walled octagonal concrete housing, each with a makeup air intake located in each upstream corner. The generators are air cooled by fans on the top and bottom of the rotor circulating air, while water cooled radiators located each corner of the generator pit removed heat from the air. The output of the each generating unit is connected to three single phase generator transformers half of which were supplied by Ferranti and the remainder by Canadian General Electric. All had two equal secondary windings which allowed them to be configured to provide either 110 kV or 220 kV. Generating units 1 to 5 are connected