RMS Duke of Lancaster was a steam turbine passenger ship operated by the London Midland and Scottish Railway from 1928 to 1956 between England and Northern Ireland across the Irish Sea.

Built at William Denny and Brothers, Dumbarton and completed in 1928, she was designed to operate as a passenger ferry between Heysham, Lancashire and Belfast.

[2][3] In August 1932 Duke of Lancaster went aground on Copeland Island in a fog, but was refloated successfully,[2] and in September 1934 collided with a trawler in Morecambe Bay.

She ran aground again at Bride at the Point of Ayre on the Isle of Man on 14 June 1937, but was refloated the following day.

[3][4] On 13 January 1940 she collided with and sank the coaster Fire King belonging to Gilchrist traders of liverpool[3] In 1941 Duke of Lancaster as requisitioned as HM Hospital Ship No.56, with capacity for 408 patients and 60 medical staff, as well as 100 crew.