Pelton Wheel
a type of water turbine invented by L. A. Pelton of California, and much used in the West and in European countries where there is a high head of water without great quantity. The stream of water is directed through a nozzle against cups or buckets on the wheel's circumference so shaped that there is no waste of energy due to shock or splashing or eddying in the cups. The water strikes against the slanting inner sides and follows the rounded contour of the cups, while side thrust is prevented by having the cups arranged in pairs with a wedge between them which divides the stream of water equally. The efficiency of the Pelton wheel is very high, namely, from 80 to 87 per cent. In the Big Creek Power Plant, California, a number of wheels about eight feet in diameter, driven by 6inch jets of water, moving moving at a velocity of 300 feet per second, develop over 20,000 horsepower apiece. At Lake Fully, Switzerland, Pelton wheels are operated by jets from a 5,000-foot head of water.