the british rail class 85 is an electric locomotive built during the early 1960s, as part of br's policy to develop a standard electric locomotive. five prototype classes (81-85) were built and evaluated, which eventually led to the development of the class 86 locomotive. the locomotives of class 85 were originally fitted with germanium rectifiers which were eventually replaced by silicon rectifiers. forty of these locomotives were built from 1961-64 by br at doncaster works. the class were used to haul trains on the then newly electrified west coast main line, from birmingham, to crewe, manchester piccadilly, liverpool and later preston. by 1965, electrification had spread south to london euston.