Changes

Fifty English Electric Type 4 (later BR Class 50) diesel locomotives were built by English Electric (EE) at their Vulcan Foundry Works plant in Newton-le-Willows between 1967 and 1968. The class was a production series of the prototype DP2 of 1962. EE owned the class and leased them to BR: the locomotives carried an owners plate to note this.  The class shared parts with other EE classes 37, 40 and 55. The 16CSVT engine of 2,700hp was a development of the 16SVT used in the Class 40. These 'advanced' Type 4 locomotives were amongst the first in the UK to include innovative features such as electronic control, dynamic braking and electric train heating incorporated into their design. The fleet was delivered in BR blue to the London Midland Region and utilised on all types of traffic, including prestige trains such as the 'Royal Scot'.<ref name=SVR156>SVR News 156</ref>

Initially the locomotives were used to haul express passenger trains on the West Coast Main Line (WCML) between Crewe and Scotland; that section not then being electrified. This often entailed ‘Multiple Working’, with two locomotives under control of a single driver. The class utilised a unique ‘Orange Square’ control, and so could only work in multiple with other class members.

By 1974 the northern WCML had been electrified, and the Class 50 fleet was being transferred to BR's BR’s Western Region to work main line passenger services out of London Paddington, replacing the 'Western Hydraulics' which were in the course of being withdrawn. The arrival of HSTs after 1976 saw them transferred onto other work, including Waterloo to Exeter trains and inter-regional trains from both Bristol and Paddington to Birmingham New Street.

The Class 50’s 50s did not originally carry names, but in the late 1970s BR agreed to their being named after Royal Navy vessels with notable records in the First and Second World Wars.

Withdrawal The low number of Class 50s made them a target for BR's fleet rationalisation plan of 1985, and they were progressively withdrawn between 1987 and 1994. 19 are preserved, six of which are based on the class began in the early 1990sSVR.