Pre-Owned R30043 RailRoad Class 57 Co-Co 57305 Network Rail Diesel LocomotivePre Owned Item, in as new condition. Test Run. Between 1998 and 2004, 33 of the locomotives were converted from Class 47s to Class 57s by Brush Traction. The Class 57 features re conditioned EMD engines and new traction alternators. Network Rail leased six Class 57s fitted with either tightlock couplings or Dellner couplers enabling them to be used as rescue engines for EMUs in the south of England, with the locomotives having fulfilled a similar