Petrol-electric transmission

From Wikipedia, the free encyclopedia
  (Redirected from Petrol-electric)
Jump to: navigation, search

Petrol-electric transmission (UK English) or Gasoline-electric or Gas-electric transmission (US English) is a transmission system for road, rail and marine transport which avoids the need for a gearbox. The petrol engine drives a dynamo which supplies electricity to traction motors which propel the vehicle or boat. The traction motors may be driven directly or, in the case of a submarine, via a rechargeable battery.

Petrol-electric transmission was used in certain niche markets in the early 20th century. For example in the petrol-electric railway locomotives produced in Britain for use on the War Department Light Railways during World War I. In France, the Crochat petrol-electric transmission system was used for standard gauge locomotives (up to 240kW of electrical power).

After World War I, petrol-electric transmission was largely replaced by diesel-electric transmission but, in the 21st century, it is making a comeback in hybrid electric vehicles.

Advantages and disadvantages[edit]

Petrol-electric transmission allows smooth, stepless, acceleration without gear changes. The disadvantages are increased cost and weight.

Historical applications[edit]


Example of petrol-electric road vehicles include the Tilling-Stevens bus (UK), the Owen Magnetic touring car (USA) and the Saint-Chamond (tank) (France). The tank used the Crochat-Colardeau system of Henry Crochat and Emmanuel Colardeau. This allowed the left and right traction motors to run at different speeds for steering and is detailed in patent US1416611.[1]


Example of petrol-electric rail vehicles include the Doodlebug (rail car)[2] and the GE 57-ton gas-electric boxcab[3] (USA) and the petrol-electric locomotives built for the War Department Light Railways by Dick, Kerr & Co. and British Westinghouse.[4] In France, the Crochat-Colardeau system of Henri Crochat and Emmanuel Colardeau was used in some petrol-electric railcars.


Most submarines which served in World War I were diesel-electric. However, some petrol-electric submarines had been built before the war. Examples include: Plunger-class submarine (USA),[5] A-class submarine (1903) (UK),[6] SM U-1 (Austria-Hungary), Russian submarine Krab (1912).

Modern applications[edit]

In the 21st century, petrol-electric transmission has gained a new lease of life in hybrid electric vehicles. Examples include: Ford Fusion Hybrid; Honda Civic Hybrid; Toyota Prius.


  1. ^
  2. ^
  3. ^
  4. ^ Davies, W.J.K. (1967). Light Railways of the First World War. David and Charles. pp. 157–159. 
  5. ^
  6. ^