The world’s first Diesel-powered locomotive was operated in the summer of 1912 on the Winterthur-Romanshorn Railroad in Switzerland. In 1906, Rudolf Diesel, Adolf Klose and the steam and Diesel engine manufacturer Gebrüder Sulzer founded Diesel-Sulzer-Klose GmbH for the manufacture of Diesel-powered locomotives. In 1909, Prussian State Railways ordered a Diesel locomotive from the company, and after test runs between Winterthur and Romanshorn the Diesel-mechanical locomotive was delivered in Berlin in September 1912. After the first world war broke out in 1914, all further trials were stopped.

Adolphus Busch purchased the American manufacturing rights for the Diesel engine in 1898 but never applied this new form of power to transportation. Guess he was to busy making beer.

General Electric (GE) entered the market in the early twentieth century, as Thomas Edison possessed an outstanding patent on the electric locomotive, his design actually being a type of electrically driven railcar. GE built its first electric locomotive prototype in 1895. Because of the cost of high electrification, GE turned its attention to Diesel power to provide electricity for electric railcars. Problems related to combining the Diesel engine with electric motor were immediately encountered.

The first significant breakthrough occurred in 1914, when Hermann Lemp, a GE electrical engineer, developed and patented a reliable direct current electrical control system. Lemp’s design used a single lever to control both engine and generator in a coordinated fashion.

This became the prototype for all Diesel-electric locomotive control systems.

Diesel-electric railroad locomotion entered the mainstream when the Burlington Railroad and Union Pacific used Diesel “streamliners” to haul passengers. Following the successful 1939 tour of General Motors’ EMD’s FT demonstrator freight locomotive set, the transition from steam to Diesel power began.

In a Diesel-electric locomotive, the diesel engine drives a generator whose output provides power to the traction motors. There is no mechanical connection between the engine and the wheels. The control system consists of the engine governor as well as electrical components used to control or modify the electrical supply to the traction motors.

Originally, the traction motors and generator were all DC. Following the development of high-capacity silicon rectifiers in the 1960s, the DC generator was replaced by an alternator using a diode bridge to convert its output to DC. This advance greatly improved locomotive reliability and decreased generator maintenance costs by elimination of the commutator and brushes in the generator. More recently, the development of high-power variable-frequency/variable-voltage drives, or “traction inverters,” has allowed the use of AC traction motors. The result is a more efficient and reliable drive that requires relatively little maintenance and is better able to cope with overload conditions that often destroyed the older types of motors.

ED GORDON is a freelance writer. He lives in Tehachapi and with his wife, Linda, is the owner of Trains, etc., located at 114 W. Tehachapi Blvd., Tehachapi.

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