British Rail Class 50

British Rail Class 50
50049 Defiance at Bath Spa Station on 3 June 2007.
Type and origin Power type Diesel-electric Builder English Electric at Vulcan Foundry Build date 1967–1968 Total produced 50
Specifications Configuration: ​  • Whyte Co-Co  • UIC Co'Co' Gauge 4 ft 8 ^1⁄2 in (1,435 mm) standard gauge Wheel diameter 3 ft 7 in (1.092 m) Wheelbase 56 ft 2 in (17.12 m) Length 68 ft 6 in (20.88 m) Width 8 ft 10 in (2.69 m) Height 12 ft 9 in (3.89 m) Loco weight 115 long tons (117 t) Prime mover English Electric 16 CSVT MU working ■ Orange Square Train heating Electric Train Heat Train brakes Dual (Air and Vacuum)
Performance figures Top speed 105 mph (169 km/h) Power output Engine: 2,700 bhp (2,010 kW) Tractive effort Maximum: 48,500 lbf (216 kN) Continuous: 33,000 lbf (147,000 N)
Career Railroad(s) British Rail Number D400–D449; later 50001–50050 Axle load class Route availability 6

The British Rail (BR) Class 50 is a diesel locomotive built from 1967–68 by English Electric at their Vulcan Foundry Works in Newton-le-Willows. Fifty of these locomotives were built to haul express passenger trains on the, then non-electrified, section of the West Coast Main Line between Crewe, Carlisle and Scotland. They were originally hired from English Electric Leasings, not being purchased outright by BR until around 1973. Under the pre-1968 classification system these locomotives were known as the English Electric Type 4. The class were affectionately nicknamed "Hoovers" by rail enthusiasts because of their distinctive engine sound, caused by the centrifugal air filters originally fitted. These proved unreliable, and were later removed, but the "Hoover" nickname stuck.