|Builder:||English Electric, Vulcan Foundry|
|Motor:||English Electric 16CSVT diesel|
|Power:||2, 700 hp (2, 013 kW)|
At first the reliability of the Class 50 was poor with failures often due to problems with the then-novel electronic systems fitted. Crews joked that they were called the Class 50 as there was only a 50:50 chance they would make it to their destinations!  They received a full refurbishment in the late 1970s/early 1980s to improve reliability by removing little used and redundant equipment such as the slow speed control.
Much of their time was spent on West of England express passenger trains out of London Paddington and London Waterloo and other passenger services. This made them vulnerable as multiple units became the favoured mode of people mover in the late 1980s and early 1990s and the supply of work dried up. There were attempts to utilise the class for slower freights and one locomotive was modified with lower geared bogies though the experiment was not a success.
The Class 50 was withdrawn from service by 1994 though no less than eighteen have been preserved (thirty six percent of the fleet) and several are mainline certified. The Class 50s were the first class of diesel locomotive to only carry BR blue livery (and later variations) though one preserved locomotive was given a "what might have been" BR green livery. One British Rail exception came in the 1980s when one Class 50 was renamed Sir Edward Elgar and repainted in Brunswick Green to commemorate the 150th anniversary of the GWR.
|50 049 in BR big logo livery at Kidderminster Town|
|50 027 in Network South East livery at Ropley|
|Two more 50s at Kidderminster, 50 031 (right) is in a fantasy "what might have been" Intercity livery|
|In original BR blue|
|50 026 at Chinnor|
 Brian Haresnape, Production Diesel-Electrics Types 4 and 5 (Ian Allan, 1984) p. 67
 Michael Welch, Diesels on the Western (Capital Transport, 2013) p. 107