British Rail Class 81

Specifications
Specifications
Configuration:;
• AAR	B-B
• UIC	Bo′Bo′
• Commonwealth	Bo-Bo
Gauge	4 ft 8+1⁄2 in (1,435 mm) standard gauge
Bogies	Fabricated steel, Alsthom suspension
Wheel diameter	4 ft 0 in (1.219 m)
Wheelbase	42 ft 3 in (12.88 m)
• Bogie	10 ft 9 in (3.28 m)
Pivot centres	31 ft 6 in (9.60 m)
Length:;
• Over beams	56 ft 6 in (17.22 m)
Width	8 ft 8+1⁄2 in (2.65 m)
Height:;
• Pantograph	13 ft 0+9⁄16 in (3.977 m)
• Body height	12 ft 4+1⁄4 in (3.77 m)
Axle load	20 long tons 4 cwt (20.5 t)
Loco weight	79.60 long tons (80.9 t; 89.2 short tons)
Electric system/s	25 kV AC Catenary
Current pickups	Stone Faiveley ‘V’-type pantograph, 2 off (later 1 off)
Traction motors	4 × AEI 189 6-pole Alsthom Quill drive 847 hp (632 kW)
• Rating 1 hour	760A
• Continuous	700A
Gear ratio	29:76 (Type A); 26:83 (Type B);
Train heating	Electric Train Heating
Loco brake	Westinghouse; Air, Rheostatic;
Train brakes	Vacuum; Dual from 1972–1973

Type and origin
Type and origin
Power type	Electric
Builder	Associated Electrical Industries at Birmingham Railway Carriage and Wagon Company
Build date	1959–1964
Total produced	25

British Railways AL1,
British Rail Class 81
British Railways AL1,; British Rail Class 81
	81004 at Birmingham New Street in 1984
Power type
Type and origin
Power type	Electric
Builder	Associated Electrical Industries at Birmingham Railway Carriage and Wagon Company
Build date	1959–1964
Total produced	25
Configuration:;
Specifications
Configuration:;
• AAR	B-B
• UIC	Bo′Bo′
• Commonwealth	Bo-Bo
Gauge	4 ft 8+1⁄2 in (1,435 mm) standard gauge
Bogies	Fabricated steel, Alsthom suspension
Wheel diameter	4 ft 0 in (1.219 m)
Wheelbase	42 ft 3 in (12.88 m)
• Bogie	10 ft 9 in (3.28 m)
Pivot centres	31 ft 6 in (9.60 m)
Length:;
• Over beams	56 ft 6 in (17.22 m)
Width	8 ft 8+1⁄2 in (2.65 m)
Height:;
• Pantograph	13 ft 0+9⁄16 in (3.977 m)
• Body height	12 ft 4+1⁄4 in (3.77 m)
Axle load	20 long tons 4 cwt (20.5 t)
Loco weight	79.60 long tons (80.9 t; 89.2 short tons)
Electric system/s	25 kV AC Catenary
Current pickups	Stone Faiveley ‘V’-type pantograph, 2 off (later 1 off)
Traction motors	4 × AEI 189 6-pole Alsthom Quill drive 847 hp (632 kW)
• Rating 1 hour	760A
• Continuous	700A
Gear ratio	29:76 (Type A); 26:83 (Type B);
Train heating	Electric Train Heating
Loco brake	Westinghouse; Air, Rheostatic;
Train brakes	Vacuum; Dual from 1972–1973
Maximum speed
Performance figures
Maximum speed	100 mph (161 km/h); Full field: 60 mph (97 km/h); Weak field: 71 mph (114 km/h);
Power output:;
• 1 hour	4 × 920 hp (690 kW)
• Continuous	4 × 847 hp (632 kW)
Tractive effort	50,000 lbf (222 kN)
Operators
Career
Operators	British Rail
Numbers	E3001–E3023, E3096, E3097; later 81001–81022
Axle load class	Route availability 6
Retired	1968 (2), 1971 (1), 1983–1991
Preserved	81002
Disposition	1 preserved, 24 scrapped

The British Rail Class 81 is a type of AC electric locomotives that formerly operated on the West Coast Main Line of British Rail's London Midland Region. Originally designated AL1, it was the first class of AC electric locomotive to be delivered to British Railways.