Diesel locomotive

A diesel locomotive is a locomotive powered by a diesel engine. The diesel engine drives the locomotive's wheels through a transmission system. Diesel locomotives are very popular worldwide, due to their ease of use and reliability. They can be more powerful than steam locomotives and do not need an expensive power grid like electric locomotives.

In the 1930s they were often used for runs of very short distances. After the middle 20th century they became the most common kind for long runs, too.

Transmission systems

Mechanical transmission uses a gearbox, shaft or chain (diesel-mechanical).
Electric transmission works by generating electricity which is in turn used to power the wheels (diesel-electric). This is the kind most used.
Hydraulic transmission uses a hydraulic transmission system (diesel-hydraulic).

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