An archive of images relating to heritage English Electric Type 4 Co-Co mixed traffic locomotives in preservation and during restoration. The fleet of fifty locomotives was constructed between 1967-68 by the English Electric Company of Great Britain. They were the last dedicated mixed-traffic locomotives built in the UK and were capable of operating at speeds of 100 mph. Following the renumbering of British Rail (BR) motive power in the 1970s they were designated as Class 50 locomotives. Eighteen of the original fleet currently remain in existence.