British Rail Class 85

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British Railways AL5 British Rail Class 85
85018 at Birmingham New Street in 1986
Type and origin Power type Electric Builder British Railways Doncaster Works Build date 1961–1964 Total produced 40
Specifications Configuration: ​  • UIC Bo′Bo′  • Commonwealth Bo-Bo Gauge 4 ft 8+1⁄2 in (1,435 mm) standard gauge Wheel diameter 4 ft 0 in (1.22 m) Minimum curve 264 ft 0 in (80 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 56 ft 6 in (17.22 m) over buffers Width 8 ft 8+1⁄4 in (2.648 m) Height: ​  • Pantograph 13 ft 0+9⁄16 in (3.977 m)  • Body height 12 ft 4+1⁄4 in (3.766 m) Axle load 20.9 t (20.6 LT; 23.0 ST) Loco weight 80 t (79 LT; 88 ST) Electric system/s 25 kV 50 Hz AC overhead Current pickup(s) Pantograph (Stone-Faiveley AMBR) Traction motors 4 × AEI Type 189 ​  • Continuous 700 A per motor Gear ratio 29:76[1] Train heating Electric Train Supply, index 66 (320 kW at 800 V AC) Loco brake Air and rheostatic Train brakes Air and vacuum
Performance figures Maximum speed 85/0: 100 mph (160 km/h) 85/1: 80 mph (130 km/h) Power output: ​  • Continuous 3,200 hp (2,400 kW) at rails Tractive effort: ​  • Starting 50,000 lbf (220 kN)  • Continuous 17,000 lbf (76 kN) at 71 mph (114 km/h) Brakeforce 67.3% of loco weight (inc. rheostatic brake)
Career Operators British Rail Numbers E3056–E3095; later 85001–85040 Axle load class Route Availability 6 Retired 1981–1992 Disposition One preserved, remainder scrapped
Specifications as at December 1986[2] except where otherwise noted.

The British Rail Class 85 (also known by the designation AL5) is an electric locomotive that was designed and produced at British Rail’s (BR) Doncaster Works during the early 1960s. While largely developed by BR, much of its systems can be attributed to the British manufacturing interest Associated Electrical Industries (AEI).^[1]

The locomotive was developed as a part of the programme of works to electrify the West Coast Main Line during the late 1950s and early 1960s. BR deliberately opted to procure multiple batches of locomotives from a range of manufacturers, leading to the procurement of five prototype classes (Classes 81-85) and subsequently placed a larger order for a refined model of one of these, eventually leading to the development of the Class 86 locomotive.

The Class 85 proved to be a relatively reliable workhorse of the London Midland region, particularly following a refurbishment during the 1970s that saw the replacement of their rectifiers. Some members of the type were in service for thirty years, their withdrawal having commenced during the mid 1980s and lasting into the early 1990s, having been effectively displaced by the arrival of newer types such as the Class 87 and later Class 90. Following the retirement of the Class 85, a single example was preserved.