Built for the Cairn Line of Newcastle, the steel steamship Cairnmona was launched form the yard of Sunderland Shipbuilding Company Ltd. on 29th November 1917. She measured 390.2′ x 53.1′ x 33.7′ and weighed 4666 gross tons, 2806 net tons. She was powered by a triple expansion steam engine built by Blair and Co Ltd., Stockton-on-Tess providing 550 net horse power.
During war service in World War One the ship survived a torpedo hit from UC-40 off the Northumberland coast on 15th June, 1918 before returning to her duties as a refrigerated a cargo ship after the end of the war. Like many of her Clan Line sister ships, she was again pressed into war service at the impending outbreak of World War Two. In the early months of 1939 she made three successful Transatlantic voyages bringing much needed supplies to Britain from Montreal, Canada as the country prepared for war. On 23rd September 1939, three weeks after war was declared, she set off once again to Montreal for her next trip arriving there on 3rd October. Over the next two weeks she loaded a general cargo of wool, copper, zinc and grain before proceeding to Halifax Nova Scotia to join convoy HX5 heading for Britain. The convoy left Halifax on the 17th October and consisted of 16 ships and 7 escort vessels. The convoy safely reached the west coast of Britain and dispersed with most of the ships heading south to Liverpool. Cairnmona, under the command of Captain Fred Wilkinson Fairley with a crew of 44 men, turned north to head through the Pentland Firth and down the Scottish east coast to her destination on the Tyne.
By late evening on the 29th she was off Kinnaird Head when she was attacked by German submarine U-13 commanded by Kapitanleutnant Karl Daublebsky von Eichhain. German sources report the attack took place at 22:50 on the 30th with the submarine firing a single torpedo which scored a direct hit on the Cairnmona.
The huge explosion fatally damaged the ship which began to fill and settle almost immediately. Three fireman were killed in the impact. She sank within 15 minutes of the torpedo hitting the ship. Thankfully the crew managed to launch Cairnmona’s lifeboats and evacuate the ship and the remaining 41 crewmen were safely picked up by the Aberdeen trawler River Lossie and the Peterhead lifeboat Julia Park Barry.
The valuable cargo of zinc and copper made her a target for salvage companies and in 1953/4 Risdon Beazley used explosives and grabs to recover much of the copper and zinc aboard. Further salvage was carried out in 1974 by Peterhead based Northern Shipbreaking Company Ltd who recovered more of the ingots not removed by Beazley’s crude technique and also removed the ship’s propeller using air diving techniques.
The wreck of the Cairnmona lies in the position 57°37.764’N, 001°43.783’W and provides a spectacular dive. She lies in 50 metres oriented 130°/310°. Despite the attentions of Rizdon Beazley and his explosives there are still massive pieces of wreckage. The bow is broken from the main midships section and the superstructure has been torn to starboard side of the ship. Her massive engines and boilers provide the highest point of the wreckage rising 5 or 6 metres from the seabed.