ACC3157 Class 37/9 37903 Railfreight Diesel LocomotiveHistory Introduced in 1986 7, the repowered Class 37 9s were an off shoot of the ill fated Class 38 project, a proposed 1,800 2,250hp Class 31 33 37 replacement with the haulage capability of a Class 56 or 58. As many as 500 units were planned, which attracted significant interest from locomotive builders and engine manufacturers from the UK, Europe and the USA. Two British manufacturers quickly established themselves among the front runners with