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Sprague

Electric Trolley System

Urban development got a major boost in 1887 when inventor Frank Julian Sprague developed the world's first successful electric street railway system, making it feasible to build cities and towns that were more vast in size and allowing for a greater concentration of businesses in commercial areas.Sprague

Born in Milford, Conn., on July 25, 1857, Sprague showed early talent in mathematics and was admitted to the United States Naval Academy in Annapolis, Maryland, from where he graduated in 1878. He served several tours as an officer on the USS Richmond, USS Minnesota and USS Lancaster, where he spent much of his time filling notebooks with mechanical drawings of devices for telecommunications and transport.

In 1881, Sprague attended the Paris Electrical Exhibition and the Crystal Palace Exhibition in Sydenham, England, where he served as secretary of the jury of awards for gas engines, lamps and dynamos. He began to develop somewhat of a reputation for ingenuity among those in industry, and in 1883, he left the Navy to accept an invitation to work as a technical assistant to Thomas Edison.

While working for Edison he developed an electric motor that could be adapted for use with industrial machinery. He also helped with the installation of Edison's groundbreaking three-wire electrical light systems and made refinements to the inventor's power distribution system. He introduced to Edison's firm the idea of using mathematical formulas rather than trial-and-error experimentation to develop concepts, which helped the company to reel in its R&D expenditures.

After just one year, however, Sprague realized that his interests lied with power and transport, rather than with lighting systems. So, in 1884, he left Edison's firm to set up his own business, the Sprague Electric Railway & Motor Company, in New York City. He began working on electrical energy and wheel suspension systems with the aim of creating an electric street railway. Commercial success with his various electric motors provided him the capital he needed to take on this task.

Prior to 1850, horse-drawn vehicles were the primary method for transport in cities. Later it was realized that by setting these vehicles on rails, horses could pull a greater load more quickly. Many cities, therefore, had built rails in the streets, and some also used cable cars. With the advent of electricity, dozens of attempts in the United States and in Europe were made to prove the feasibility of an electricity-powered service, with varying degrees of success.

Sprague was able to conquer a number of challenges with a comprehensive system that incorporated several designs he invented himself, including improved electrical energy systems, wheel suspension, automatic controls, automatic brakes and a non-sparking motor that could maintain constant revolutions with varying loads. In 1887, Sprague began the installation of a 12-mile electric rail system in Richmond, Virg., for the Richmond Union Passenger Railway. This was to be the first large-scale electric trolley line in the world. It opened with great fanfare on Feb. 2, 1888.

The system's success proved the efficiency, safety and financial viability of an electric-powered street rail service, and within a decade, horse-powered rail and cable car vehicles were all but obsolete. The city of Boston ordered the world's second electric rail system after evaluating Sprague's Richmond installation, and others followed around the world, with 20,000 miles of streetcar tracks laid in the United States alone by 1905. His system served as the basis for a variety of systems later built by competitors such as Thomas-Houston, General Electric and Westinghouse.

In 1890, Sprague sold his company to the Edison General Electric Company. In 1892, he formed a new venture, this time to work on vertical transport, in the form of electric elevators. Via the Sprague Electric Elevator Company, Sprague and associate Charles Pratt invented the Sprague-Pratt Electric Elevator, which employed Sprague's all-important method of returning power to main supply systems. The elevator had the ability to carry heavier loads and move more quickly than hydraulic or steam elevators. He sold nearly 600 elevators for buildings around the world before selling the firm to the Otis Elevator Company in 1895.

That year, he began working on a multiple-unit system for electric railway operation, which greatly contributed to the development of electric traction. He also designed a safety system for automatic train control via yet another new enterprise, the Sprague Safety Control & Signal Corporation; from 1896 to 1900 he served on the Commission for Terminal Electrification of the New York Central Railroad. Later, in the 1920s, he returned to the elevator-building arena, designing a dual-elevator system that allowed for the operation of two elevators in a single shaft. He sold this to the Westinghouse Company.

Sprague is said to have continued innovating up until his death on October 25, 1934, at the age of 77. His numerous honors and awards include the 1889 gold medal at the Paris Electrical Exhibition, the grand prize at the St. Louis Exhibition in 1904, the 1910 Edison Medal of the American Institute of Electrical Engineers, and the Elliott-Cresson Medal awarded by the Franklin Institute in 1904. He was also the recipient of the Franklin Medal in 1921, and was awarded the John Fritz Gold Medal posthumously in1935. He is buried in Arlington National Cemetery in Washington, D.C.

[April 2006]

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