BR Class 20

Introduced in the 1950s, the English Electric Type 1 locomotive marked a significant milestone in British Railways' transition to diesel power. As the first major step towards dieselisation, this locomotive showcased promising capabilities with its 1000hp (746 kW) engine. Over a span of eleven years, from 1957 to 1968, a total of 228 Type 1 locomotives were manufactured.

The Type 1 locomotives were deployed to replace steam locomotives of similar power, primarily serving in the transportation of light and mixed-freight traffic across the Midlands and in Scotland. Notably, these locomotives stood out with their distinctive single cab design, setting them apart from newer locomotives of the time.

Extreme realism

The unique design of the English Electric Type 1 locomotives included a cab located at the rear of the locomotive. This cab featured controls that could face either direction, giving the locomotives a resemblance to tank engines. Similar to steam locomotives, the diesel engine and on-board equipment were positioned in front of the cab, akin to a firebox and boiler arrangement. Adding to their steam-like characteristics, headcode discs were mounted on each end of the locomotive, a feature present in the initial batch of 127 Type 1 locomotives.

Due to concerns about visibility when operating in the forward direction, it became common to see pairs of Type 1 locomotives coupled together at the nose. This configuration allowed for a better view of the track ahead and provided the added advantage of doubling the combined horsepower, enabling the handling of heavier trains.

Following the implementation of the TOPS (Total Operations Processing System) classification system, the English Electric Type 1 locomotives were reclassified as BR Class 20s. However, they are colloquially known as "Choppers" due to the distinct sound of their engines resembling the noise produced by helicopters when operating under load.