ABB125
Established Member
I see, thanksIt's not that it's a different loco, it's that swapping them over will involve coupling and uncoupling and you therefore need to check that this has been done properly, in particular that the multiple working jumpers are functioning.
I can recall a couple of occasions where the Manchester Mk3 set went backwards when driven from the DVT. A notice went up at ATC Crewe to the effect that a forward & reverse test should be done before the set leaves the shed.