0758 - Photo: Paul Gildersleve.

Deltics were at their best with two operable power units though situations did arise when the locomotives were put to use when restricted to only one. Here 55006 (D9006) "THE FIFE & FORFAR YEOMANRY" is seen at York on the 18th August 1978 shortly after arrival with the 1E18 13:40 Edinburgh - York service having powered the train with only one engine in use. 55006 entered Doncaster Works two days later on Sunday 20th August when it had its No.2 power unit 442 replaced by 438.