[3] After graduating, Campbell was employed by the London, Midland and Scottish Railway, and then served in the Royal Air Force during the Second World War.
On demobilisation, in 1947 Campbell began working for British Railways; he was employed in engineering design and construction.
[3] In 1965, Campbell was appointed chief civil engineer for the Scottish Region of British Railways.
[1] In 1977, he became a member of the British Railways Board (BRB) with responsibility for engineering and research,[6] and was appointed chief executive in June 1978, taking over from David Bowick.
[15] He was also appointed a Commander of the Royal Victorian Order (CVO) in the 1977 Silver Jubilee and Birthday Honours.