bulletin intended to assist bridge engineers in designing electrical equipment on movable bridges has bom published by the U.S. Bureau of Public Roads.—The authors point out that bridge engineers we been guided by manufacturers in the selection of major power unite, and have placed almost entire dependence upon them in selection of control and interlocking devices, The electrical principles involved fare set forth as an nid in deciding the type of equipment required, in supervising canstruction, and in maintaining the equipment. Subjects discumed include the fundament-ale of motor types, selection of motors for different services, control and interlocking of operations, different installations of electrical equipment, and new developments electrical bridge control.
Text read from the printed page and cleaned; old type leaves the occasional error.