Class 85 (AEI/British Railways AL5)

British Railways, in it's wisdom, split an order for 100 AC electric locomotives for the West Coast Main Line five ways. The largest share however, was kept in house with 40 of the locomotives built at BR's Doncaster Works using AEI electrical equipment. The Class 85 was similar to the BRCW Class 81, having the same AEI equipment. However, the Class 85 had semiconductor based rectifiers (at first a mixture of germanium and silicon, later retrofitted to be all silicon) and rheostatic braking [1].

Information
Number built:	40
Built:	1961-64
Builder:	Associated Electrical Industries / BR Doncaster
Motor:	4 AEI 189 traction motors (25kV AC OHLE)
Power:	3, 200 hp (2, 400 kW)
Wheel arrangement:	Bo-Bo

The Class 85 (along with the 81) proved to be the best of the prototype AC electrics, their only real issue being ride quality at top speed. They were displaced from expresses by the Class 86 but remained in service on secondary passenger services and freight until the early 1990s when they were finally withdrawn. One has been preserved.

85 006 preserved at Barrow Hill

[1] Brian Haresnape, Electric Locomotives (Ian Allan, 1983) p. 61