Originally built as Class 47 (Brush Type 4's), the Class 57's were rebuilt in the period 1997 - 2003 (hence the term 'Bodysnatchers) by Brush Traction at Loughborough using refurbished General Motors diesel engines and fitted with Brush Alternators and Traction Motors, 57/0's and 57601 were fitted with 2500HP GM645 - 12E3 engines, while 57/3's and 57602 - 57605 had GM 645 F3B-12 engines producing 2750HP.