HM Troopship Somersetshire was 7,456 gross tonnes (Bibby Line). She was built in 1927 and converted into a troopship with accommodation for 1,300 troops. In October 1927 the ship sailed to China and from January to May 1928 she transported troops to Karachi and was laid up in Dartmouth thereafter. In September 1939, the Somersetshire was requisitioned and converted into HM Hospital Ship No. 25 with 507 beds, 118 medical staff and 171 crew members. She participated in the withdrawal from Narvik in April 1940 and on 6 December 1940, was bombarded from shore as her launches brought of the wounded at Tobruk. In February 1941, the ship joined her sistership Dorsetshire in evacuating the wounded from the besieged Tobruk, before operating from the Red Sea to South Africa, Australia and New Zealand repatriating wounded soldiers.

At 12.57 hours on 7 April 1942, German u-boat U-453 fired a spread of four torpedoes at a steamer of 10,000 gross tonnes and heard three detonations after 47 seconds. HMHS Somersetshire was not recognised as a hospital ship by the U-boat anf ortunately she was carrying no patients. The hit was on the starboard side, forward, and Somersetshire settled by the head with a list. One crew member and six Royal Army Medical Corps staff were lost. 114 crew members, 64 medical staff members and two stewardesses abandoned ship in 13 lifeboats. The crew later reboarded her and managed to reach Alexandria on the port engine and assisted by tugs. The remaining survivors were picked up by a Greek destroyer.

From 1944 to 1946, the Somersetshire sailed all over the world as a hospital ship and finishing up in the Pacific. In February 1948, the ship was decommissioned and rebuilt until November by Harland & Wolff to a passenger ship with accommodation for 550 passengers. In 1953, the ship briefly returned to trooping to East Africa during the Mau Mau troubles and in 1954 was broken up by Thos. W. Ward in Barrow-in-Furness.