An Electric Pump Plant.
An electric pump plant has been built by Scott & Mountain (Limited) of the Close Works, Newcastle-on-Tyne, for the North Seaton colliery. These pumps were designed to deliver 250 gallons of water per minute through 1300 yards of eight-inch pipe, against a heading of fifty feet. The motor which drives them gives twenty horse-power when running at its nominal speed of 720 revolutions per minute. This speed is reduced to the thirty revolutions at which the pump shaft runs by worm gearing. The worm, which runs in an oil bath, is of wrought-iron, and the worm wheel is phosphor bronze. A thrust bearing is employed to take up the pressure in the worm spindle. The pumps are three in number. The rams are of gun metal, nine inches in diameter, and the stroke is fifteen inches. The crank shaft and connecting rods are steel. The dynamo which supplies the current to the motor does so through a cable 2700 feet long. A special switch is used at the motor end to prevent sparking at the terminals when starting. The dynamo is belt driven, being designed to run at 800 revolutions per minute, at which speed its output is sixty-five amperes at 300 volts. It can be used for electric lighting when not working the pump. The engine which drives the generator is of the vertical type, having a single cylinder thirteen inches in diameter with a ten-inch stroke. It is intended to run at 200 revolutions per minute.