BR Southern Region / English Electric

'BR Southern Region / English Electric' is used in this encyclopedia where a locomotive class was designed jointly by the Southern Region engineering office and English Electric as the prime contractor. EE's traction expertise, its Vulcan Foundry locomotive works at Newton-le-Willows and its electrical works at Bradford and Preston, gave the Region a partner well-suited to its 750 V dc third-rail and overhead high-voltage electric requirements.