Pre-war

Clan Matheson was ordered by Australian Steamship Ltd, Sydney in 1917 as the 4,360 GRT Bogong. It was later decided to rename her You Yangs. The contract was sold to Clan Line Steamers Ltd on the orders of the British Shipping Controller. Her design was modified and she was lengthened.^[1]

Clan Matheson was placed under the management of Cayzer, Irvine & Co Ltd, who registered her at Glasgow. Her United Kingdom official number was 141086 and her code letters were JWPR.^[2] In 1934 her code letters were replaced with the Call sign GQMW.^[3] Clan Matheson was a cargo ship, and also served as a cadet training ship.^[4]

In 1924 the Levuana Moth (Levuana iridescens) was a serious pest to coconut palms in Fiji and a biological solution was devised. A similar moth, Artona catoxantha was known to be parasitized by Ptychomyia and Apanteles, so it was decided to use these parasites to eradicate the Levuana Moth. The parasites had to be imported from Singapore to Fiji. Most ships at that time sailed not direct but via Australia, which would have meant putting the parasites into quarantine in Australia.

Clan Line operated ships in the area. In July 1924 Clan Mackay was sailing from Singapore to Fiji via other ports, and Clan Matheson was also due to sail from Java to Fiji. Clan Mackay took the parasites to Surabaya, Java, where they were transferred to Clan Matheson for onward shipment to Fiji. No Apanteles survived, but the Ptychomia did and their introduction succeeded in eradicating the Levuana Moth within two years.^[5]

Second World War

In the Second World War Clan Matheson sailed in convoys.

HX 229

The following month Clan Matheson, carrying general cargo, mail and a passenger, joined Convoy HX 229 and carried the convoy's Vice Commodore. 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]

Approximate position of Empire Claire's wreck

Post war

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.^[9] In 1951 she was sold to the Heron Steamship Co Ltd of London who renamed her Claire T.^[10] In 1953 she was sold to the Romney Steamship Co Ltd,^[11] serving until 1955 when she was purchased by the MoT and renamed Empire Claire.

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.^[10]