British Rail Class 73

class of 49 electro-diesel locomotives

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 typeElectro-diesel
Builder73/0: British RailwaysEastleigh Works
73/1: English Electric at Vulcan Foundry
Build date1962, 1965–1967
Total produced49
 • WhyteBo-Bo
 • UICBo'Bo'
Gauge4 ft 8 12 in (1,435 mm) standard gauge
Wheel diameter3 ft 4 in (1.016 m)
Length16.36 m (53 ft 8 in)
Loco weight73/0: 76.30 long tons (77.52 t)
73/1: 76.80 long tons (78.03 t)
Electric system/s660–750 V DC
Current pickup(s)Third rail
Prime moverEnglish Electric 4SRKT Mk II
Traction motors73/0: EE 542A
73/1: EE 546/1B
Train heatingElectric Train Heating
Train brakesVacuum, Air and Electro-Pneumatic
Performance figures
Top speed73/0: 80 mph (129 km/h)
73/1: 90 mph (145 km/h)
Power outputElectric (continuous): 1,420 hp (1,059 kW)
Electric (one-hour): 1,600 hp (1,193 kW)
Engine: 600 hp (447 kW)
Tractive effort73/0 (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)
Railroad(s)British Rail
FM Rail
Gatwick Express
Network Rail
South West Trains
NumberE6001–E6049; later 73001–73006, 73101–73142
Axle load classRoute 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

References change

  1. It's now at Long Marston