In October 1939 Clan Matheson carried general cargo from Britain to East Africa.

[6] Clan Matheson was a member of Convoy OG 22, which formed at sea on 18 March 1940 bound for Gibraltar.

She was due to join Convoy HX 228, which left New York on 28 February 1943 and reached Liverpool on 15 March, but instead she returned to port.

HX 229 left New York on 8 March 1943 bound for Liverpool, and Clan Matheson was meant to sail with the convoy as far as Loch Ewe, but she was unable to maintain speed and put into Halifax, Nova Scotia.

[8] In 1948 Clan Matheson was sold to British & South American Steam Navigation Co Ltd, which renamed her Harmodius and appointed Houston Line Ltd to manage her.

As part of Operation Sandcastle she was loaded with obsolete war materiel which included confiscated German munitions containing Tabun.

[12] Loaded with 16,000 bombs,[13] On 27 July 1955 Empire Claire was towed out of Stranraer[9] and scuttled in the North Atlantic 800 miles northwest of County Donegal, Ireland[13] at 56°30′N 12°00′W / 56.500°N 12.000°W / 56.500; -12.000.

[10] On 19 September 2013 Royal Mail issued a set of six postage stamps commemorating the British Merchant Navy.