Engineering Wonders of the World
Volume I

WATER-POWER STATIONS OF NIAGARA FALLS. 301 A WHEEL-PIT OF THE NIAGARA FALLS POWER COMPANY, WITH STEEL FRAME FOR FLOOR OF POWER- HOUSE PARTLY CONSTRUCTED. (Photo, Orrin E. Dunlap, Niagara Falls, N.Y.) The lower level for the discharge of the water carried through the penstocks is ob- tained by sinking through the rock, for a distance equal to the height of the Falls, a long, narrow shaft, or wheel-pit, over which the power-house itself is built. Down this shaft passes a series of parallel vertical pen- stocks, carrying to the turbines below the water diverted from the river. On leaving the turbines the water falls to the bottom of the pit, and thence finds an outlet to the lower level of the river below the Falls through a long tunnel, cut in the rock at an average depth of 200 feet below the surface. The mechanical power developed by each turbine is transmitted to the electrical gener- ators installed on the power-house floor by revolving vertical steel shafts passing up through the wheel-pit, there being one gener- ator for each turbine. A governor placed at the side of a generator operates valves in its turbine below, automatically controlling the supply of water in accordance with any change in the amount of electrical output by its gener-, ator, thus maintaining a constant speed what- ever variations occur in the load. In. the two power-houses on the American side the capa- city of the turbi xes and generators is 5,000 or 5,500 horse-power each, while in the Canadian plant units of 10,000 horse-power are installed.