The steel steamship Durham Castle was built by Fairfield Shipbuilding and Engineering in Glasgow and was launched on 17th December 1903. She was 475.4′ x 56.7′ x 31.6′ and was 8240 gross tons and 5077 net tons. Powered by an 8 cylinder compound steam engine by Fairfields delivering 969 nhp she initially served for her owners, the Union Castle Mail ans Steamship Company Ltd, on the Cape of Good Hope to Mombassa route.
She continued in commercial service throughout World War One although she was occasionally hired by the Admiralty to be used as a troopship during the conflict. After the war she continued to sail on routes up and down the East coast of Africa and north through the Suez Canal to ports on the Mediterranean coast of Africa. Her long service came to and end when she was withdrawn from service in 1939 to be replaced by the RMS Pretoria Castle. Her retirement coincided with the outbreak of World War Two and, although schedule to be dismantled by Metal Industries, she was acquired by the Admiralty who planned to use her as an accommodation ship to be anchored in Scapa Flow.
On 26th January 1940 she was under tow heading north to take up her her new role when she struck a mine laid by U-57 (Commander Klaus Korth) off the naval anchorage at the Cromarty Firth. The approaches to the important naval base were continual targets for the German minelaying submarines. She sank immediately a few miles east of the North Sutor, a rocky headland guarding the north side of the entrance to Cromarty.
The wreck of the Durham Castle lies in position 57°41.482’N, 003°54.184’W (WGS84) oriented 160°/340° in 20 metres of water. The wreckage, which lies mostly buried in the sandy seabed is now mainly large steel hull plates and other broken debris rising no more than 2 metres from the seabed. Given the position of the wreck, which lies directly off the entrance to the Cromarty Firth, and the state of the wreckage it is almost certain that she was dispersed at some point although surveys in the 1960’s report that the hull, with the large hole where the mine exploded clearly visible, was still reasonably in tact. It is possible that the wreck was dispersed after this date as the Cromarty Firth came into use as a base for the huge oil drilling platforms of the North Sea.