British Rail Class 73

Specifications
Specifications
Configuration:;
• AAR	B-B
• UIC	Bo'Bo'
• Commonwealth	Bo-Bo
Gauge	4 ft 8+1⁄2 in (1,435 mm) standard gauge
Wheel diameter	3 ft 4 in (1,016 mm)
Length	16.36 m (53 ft 8 in)
Loco weight	73/0: 76.3 long tons (77.5 t; 85.5 short tons); 73/1: 76.8 long tons (78.0 t; 86.0 short tons)
Electric system/s	660–750 V DC Third rail
Current pickup(s)	Contact shoe
Prime mover	English Electric 4SRKT Mk II; 2 × Cummins QSK19 (73951-2); MTU 8V 4000 R43L (73961-971)
Traction motors	73/0: EE 542A; 73/1: EE 546/1B
MU working	73/9: AAR system; (59, 66, 67, 68 008-015, 69, 70, and 73/9)
Train heating	Electric Train Heating
Train brakes	Vacuum, Air and Electropneumatic

Type and origin
Type and origin
Power type	Bi-mode (electro-diesel)
Builder	73/0: British Railways at Eastleigh Works; 73/1: English Electric at Vulcan Foundry
Build date	73/0: 1962; 73/1: 1965–1967
Total produced	49

British Rail Class 73
British Rail Class 73
	A GB Railfreight Class 73/9 at Connel Ferry in 2016
Power type
Type and origin
Power type	Bi-mode (electro-diesel)
Builder	73/0: British Railways at Eastleigh Works; 73/1: English Electric at Vulcan Foundry
Build date	73/0: 1962; 73/1: 1965–1967
Total produced	49
Configuration:;
Specifications
Configuration:;
• AAR	B-B
• UIC	Bo'Bo'
• Commonwealth	Bo-Bo
Gauge	4 ft 8+1⁄2 in (1,435 mm) standard gauge
Wheel diameter	3 ft 4 in (1,016 mm)
Length	16.36 m (53 ft 8 in)
Loco weight	73/0: 76.3 long tons (77.5 t; 85.5 short tons); 73/1: 76.8 long tons (78.0 t; 86.0 short tons)
Electric system/s	660–750 V DC Third rail
Current pickup(s)	Contact shoe
Prime mover	English Electric 4SRKT Mk II; 2 × Cummins QSK19 (73951-2); MTU 8V 4000 R43L (73961-971)
Traction motors	73/0: EE 542A; 73/1: EE 546/1B
MU working	73/9: AAR system; (59, 66, 67, 68 008-015, 69, 70, and 73/9)
Train heating	Electric Train Heating
Train brakes	Vacuum, Air and Electropneumatic
Maximum speed
Performance figures
Maximum 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); 73/9: 1,600 hp (1,193 kW)
Tractive effort	73/0 (electric): 42,000 lbf (186.8 kN); 73/0 (diesel): 34,100 lbf (151.7 kN); 73/1 (electric): 40,000 lbf (177.9 kN); 73/1 (diesel): 36,000 lbf (160.1 kN)
Operators
Career
Operators	British Rail; GB Railfreight; Network Rail; Southern; South Western Railway;
Numbers	E6001–E6049; later 73001–73006, 73101–73142
Axle load class	Route availability 6
Withdrawn	1972 (1), 1982 (1), 1991–present
Disposition	6 preserved, 27 still in service; 6 stored, 10 scrapped

The British Rail Class 73 is a British electro-diesel locomotive. This type is unusual in that it can operate on the Southern Region's 650 / 750 V DC third rail power supply, or an onboard diesel engine to allow it to be used on non-electrified routes. This makes it very versatile, although the diesel engine produces less power than is available from the third-rail power supply, so the locomotives are rarely used outside of the former Southern Region of British Rail. It is one of the first bi-mode locomotives ever built. Following the withdrawal and scrapping of the more powerful Class 74 bi-mode locomotives in 1977, the Class 73 was unique on the British railway network until the introduction of the Class 88 bi-mode locomotives in 2017. Ten locomotives have been scrapped.