ELECTRIC RAILWAYS. Conduit elec tric railways are those having some form of conduit or trough below the level of the rails, either between them or at the side of the track. Usually there is a short or continuous opening to the street. through which the 'plow' projects from the bottom or side of the ear. Heside the conduit, supported upon suitable insulators, pins, or brackets, are generally the conductors. against which suitable rollers or rubbing blocks, forming Part of the plow, are pressed. In this way cur rent can be taken from one conductor up through the slot on a wire imbedded in the plow, through the motor. and again back to the other conductor. Various other kinds of conduit systems have been devised, but the one described is the only one which has reached any commercial success. The conduit electric railways of New York and Washington have the conduit between the rails; the only side-conduit railway of im portance is that at Budapest, Hungary. As con structed in America, a trench about 2 feet deep at the centre and 6 feet wide is dug along the line of the road, and heavy cast-iron yokes. weighing from 400 to 500 pounds, are placed crosswise of this trench about every 4 feet. To these yokes are bolted the tracks and the rails forming the edges of the slot. Between these yokes and around them is placed concrete, with a trough in the centre to form the conduit.
Between and at the sides of the tracks at in tervals of about 15 feet small covered openings are made into the conduit, and at these points heavy cast-iron and porcelain insulators are bolted to the slot-rails. These have pins pro jecting down into the conduit, to which steel Trails are bolted. The ear-plows extend through the slot and have rubbing-blocks which press against the conductor rails. Current is sup plied to these conductors by feeders or which run in underground conduits alongside the track from the power station. and are at Inched at intervals to the conductor rails. Drainage is secured by frequent outlets from the conduits to sewers, and manholes at inter vals give access to the conduit for repairs. Conduit railways are far more expensive to const rnet than overhead-trolley linos. eh ietly because of the elaborate track and conduit con struetion required. and because of the necessity of removing underground pipes which interfere with the conduit. The most notable conduit elee trk railway systems of the United States are those of New York City and of Washington, 1). C., the New York system aggregating over 100 miles of line in 1900.