Sprague, Frank (Julian) (1857-1934)

US electrical engineer and inventor. In 1887 he installed the USA's first electric trolley system in Richmond, Virginia. He perfected a control system for multiunit trains in 1895, using this as a basis for an automatic train control system he developed. In his later years he produced electric motors for small tools and appliances and coinvented the third rail for electrified rail lines.

He was born in Milford, Connecticut. He developed an interest in electricity while a cadet at the US Naval Academy. As a junior naval officer 1878-83, Sprague experimented with various types of dynamos and motors. He resigned from the Navy to become an assistant to Thomas Edison in 1883. He formed the Sprague Electric Railway and Motor Company in 1884. He sold this company to Edison in 1892. He subsequently established a concern that manufactured electric elevators, selling it in turn to Otis Elevator Company. He served as chairman of committees on shipbuilding and electricity for the Naval Consulting Board during World War I. He has been called ‘the father of electric railway traction’.