Metropolitan Railway electric locomotives were used on London's Metropolitan Railway with conventional carriage stock. On the outer suburban routes an electric locomotive was used at the Baker Street end that was exchanged for a steam locomotive en route.
The first ten had a central cab and were known as camel-backs, and these entered service in 1906. A year later another ten units with a box design and a driving position both ends arrived. These were replaced by more powerful units in the early 1920s.
The locomotives were withdrawn from passenger service in 1962 after electrification reached Amersham and the A Stock electric multiple units entered service. One locomotive is preserved as a static display at London Transport Museum.