British Rail Class 73

The British Rail Class 73 electro-diesel locomotives are very unusual in that they can operate from a 750 V DC third-rail supply but also have a diesel engine to allow them to operate on non-electrified routes. This makes them very versatile, although the diesel engine produces less power than is available from the third-rail supply so they rarely stray from the former Southern Region of British Rail. Following the withdrawal of the more powerful Class 74 electro-diesels in 1977, the Class 73 is now unique on the British rail system.

British Rail Class 73
Class 73, no. 73201 at Woking. This locomotive was used by South West Trains as a “Thunderbird” to rescue failed trains.[1]
Type and origin Power type Electro-diesel Builder 73/0: British Railways’ Eastleigh Works 73/1: English Electric at Vulcan Foundry Build date 1962, 1965–1967 Total produced 49
Specifications Configuration: ​  • Whyte Bo-Bo  • UIC Bo'Bo' Gauge 4 ft 8 1⁄2 in (1,435 mm) standard gauge Wheel diameter 3 ft 4 in (1.016 m) Length 16.36 m (53 ft 8 in) Loco weight 73/0: 76.30 long tons (77.52 t) 73/1: 76.80 long tons (78.03 t) Electric system/s 660–750 V DC Current pickup(s) Third rail Prime mover English Electric 4SRKT Mk II Traction motors 73/0: EE 542A 73/1: EE 546/1B Train heating Electric Train Heating Train brakes Vacuum, Air and Electro-Pneumatic
Performance figures Top speed 73/0: 80 mph (129 km/h) 73/1: 90 mph (145 km/h) Power output Electric (continuous): 1,420 hp (1,059 kW) Electric (one-hour): 1,600 hp (1,193 kW) Engine: 600 hp (447 kW) Tractive effort 73/0 (electric): 42,000 lbf (186.8 kN) 73/0 (diesel): 34,100 lbf (151.7 kN) 71/0 (electric): 40,000 lbf (177.9 kN) 73/1 (diesel): 36,000 lbf (160.1 kN)
Career Railroad(s) British Rail Eurostar FM Rail Gatwick Express FirstGBRf Network Rail South West Trains Number E6001–E6049; later 73001–73006, 73101–73142 Axle load class Route availability 6

Class 73, no. E6013 (73107) at Rowsley South, on the Peak Railway on 17 April 2003. This locomotive was on loan from Fragonset Railways, and has since returned to main-line service.

Class 73/1 73101 in BR blue livery