Frank J. Sprague

Frank Julian Sprague ( born July 25, 1857 in Milford, Connecticut, † October 25, 1934 ) was an American naval officer and inventor. He is regarded in the U.S. as "the father of electric traction " and made significant contributions to the development of electric motors, electric railways and lifts.

Early Developments

Frank Julian Sprague attended Drury High School, where he showed outstanding performance in mathematics. In 1874 he began studying at the United States Naval Academy in Annapolis, Maryland, from which he graduated in 1878 as the seventh best in his class. He then served on various ships of the U.S. Navy, in which he included on the USS Lancaster, the first electric Signalrufsystem on a Navy ship.

Sprague took his departure in 1881 to participate in the Paris Electrical Exhibition and at the Crystal Palace Exhibition in Sydenham, England in 1882. There he was a jury member for the award ceremony for gas engines, dynamos and lamps.

Employees of Edison

1883 made ​​him a business partner of Thomas Alva Edison to cooperate. Sprague led Edison's laboratory in a mathematical methods, which reduced the considerable expense for the hitherto pursued trial- and-error methods. He improved Edison's system of lines and distributions in electrical systems. In 1884 he decided to go his own way and founded the Sprague Electric Railway & Motor Company.

Sprague's company introduced in 1886 two major improvements one: the constant speed electric motor with spark-free solid brushes and the energy recovery of electrically powered devices. With its motor constant speed under varying load were first reached. Edison praised this as the only practically useful engine of its time. The method of energy recovery is also considered essential for the development of electric railways and lifts.

Electric railways

Sprague developed in 1888 a tramway car, which drew its power from an overhead line and thus built the first successful large electric street railway system in Richmond, Virginia. In this handled on the hills of Richmond climbs to 10 %, which proved to be a convincing test of the application of the new technology in other cities. Within a year, the electricity had prevailed over the horse business, and to 1889, 110 electric trains were with Sprague's equipment under construction or in planning. Edison, who made Sprague's equipment, bought it on 1890.

Sprague's intermediate experiences with the elevator control led him early to project a Allachsantrieb of multiple units. In his multiple unit system, each car had its own drive motor. About relays and running through electrical wires, the driver should have control of the train evenly and efficiently. Specific locomotives should thus be saved.

Sprague's first assignment with this technique came from the South Side Elevated Railway in Chicago. The successful use led to further orders in Brooklyn, New York and Boston.

From 1896 to 1900 Sprague of New York Central Railroad served in the electrification of the railway stations, particularly the Grand Central Terminal in New York City. Here he developed an Automatic Train Protection, and then founded the Sprague Safety Control & Signal Corporation to develop and market his system.

Electric lifts

Sprague turned to 1890, the development of electric lifts to and founded in 1892 the Sprague Electric Elevator Company and developed with Charles R. Pratt Sprague - Pratt Electric Elevator, which was faster and more powerful than the hydraulic or steam-powered elevators. Sprague sold his company then to the Otis Elevator Company.

In the 1920s he designed a system for the operation of two independent elevators in the same shaft as well as security systems. Sprague sold his system then the Westinghouse Electric Corporation.

Awards and estate

Sprague received the gold medal at the Paris Electrical Exhibition in 1889, the Grand Prize at the St. Louis Exhibition in 1904, the Elliott Cresson Medal in 1904, the Edison Medal in 1910, the Franklin Medal in 1921 and posthumously the John Fritz Medal Gold 1935.

With his wife Harriet Sprague had two sons, Robert and Julian. After his death in 1934 Sprague was buried at Arlington National Cemetery. His widow gave numerous items from his collection to the New York Public Library. 1959 was built with donations from the Harriet Sprague Sprague Building on Shoreline Trolley Museum in East Haven ( Connecticut ), near Sprague's hometown Milford. The museum is the oldest operating tram museum and has one of the largest collections in the United States.

1999 intersected two grandchildren, John L. Sprague and Peter Sprague, the band and started a Sprague- engine from 1884, and thus a new permanent exhibition, Frank J. Sprague: Inventor, Scientist, Engineer, at the Shoreline Trolley Museum.