90021 is a nocturnal locomotive seeing use on the Caledonian

Sleeper services between Scotland and London. It is seen here at Waverley stabled between duties wearing its First Group and EWS liveries with its compressor gently ticking away. I can't help but think that this does not represent the best use of an expensive resource to the railways and probably goes some way to explaining why the sleeper services operate at a loss relying heavily on a considerable subsidy from the Scottish Government.