Hermann Lemp

Who was Hermann Lemp?

Hermann Lemp born: Heinrich Joseph Hermann Lemp was a Swiss-American electrical engineer; he is credited as the inventor of the modern system of diesel electric traction co-ordination and control.

Born and educated in Switzerland, he emigrated to America aged 19, hoping to work with T. A. Edison. He joined Edison General Electric and worked with Edison on electrical projects, including one of Edison's first electric locomotives. A short while later he joined Elihu Thomson, of the Thomson-Houston Company. That company became part of General Electric, to which Edison acted as consultant.

He met Rudolf Diesel on his visit to the USA in 1911, and was an invited observer at the trials of Diesel's direct-drive 1,000 hp locomotive in 1912. The diesel engine was too powerful for the mechanical gears. Lemp, with his colleagues, persuaded GE that diesel traction had a future, but that a non-mechanical transmission system was required. The proposed transmission was electrical, using the diesel engine to power a generator that supplied current to the traction motors. However, such a system would need a device to coordinate engine and generator output. He invented one, patented in 1914.