The four main engines (500 hp Paxman) fed into a central gearbox via differentials, the loco could run on one, two, three or four depending on power required. There were also two 150hp railcar engines, these drove the superchargers for the main engines. It should be noted that at the time this was the most powerful single unit diesel in Britain, not bettered until the prototype Deltic a few years later. It was withdrawn in August 1958, not because it didn't work and not as a result of an engine fire as usually reported - the reason was given as too high maintenance costs.