British Rail Class 37

The British Rail Class 37, also known as the English Electric Type 3, is a diesel-electric locomotive ordered as part of the British Rail modernisation plan. English Electric put forward a design based on locomotives it had already supplied to railways in East Africa, and British Railways placed an order for forty-two in January 1959 with no prototype. The first was delivered in November 1960 and entered service on 2 December, and the final locomotive reached the Western Region on 9 November 1965. Construction was split between Vulcan Foundry at Newton-le-Willows and Robert Stephenson and Hawthorns of Darlington, and 309 were produced in total, numbered in the D6600 to D6608 and D6700 to D6999 ranges. A general purpose design, the class became a familiar sight on British Rail, notably on InterCity services in East Anglia and Scotland, and many are still in use on freight, maintenance and empty stock movement duties. Enthusiasts know the locomotives as tractors, because the sound of the engine resembles that of a tractor.