During May 2013, a number of events were held in the UK and Canada to commemorate the 70th anniversary of the 1943 turning point in the Battle of the Atlantic – the battle to ship vital supplies to Britain from the USA and Canada which lasted for the whole duration of the 1939-45 war with Germany.
As the war progressed, it soon became apparent that large numbers of escort craft were required to protect the convoys of merchant ships crossing the North Atlantic from attacks by German submarines – unterseebooten, which the British called U-boats. Small shipyards around Britain set to work on vessels of a simple and austere design which could be built quickly. To boost the morale of those who would have to face the Atlantic storms as well as the enemy in these tubby, uncomfortable, unglamorous craft, a name from the romantic age of sail was revived for them – the corvette.
Troon’s Ailsa Shipbuilding Company Ltd received orders for two Flower Class corvettes which would see much wartime action, but not in the British Navy. They would both be crewed by exiles who were continuing to fight alongside the British after their countries had been overrun, Acanthus being transferred to the Royal Norwegian Navy and Aconite to the Free French Naval Forces.
Work began on Acanthus in December 1939. In late September 1941 the completed vessel came under Norwegian command at Troon. Having worked up to operational readiness, she was soon in action, taking part in the commando raid on the Lofoten Islands, off the Norwegian coast, in December 1941. For most of her war service, Acanthus escorted Atlantic convoys. Although not credited with actually sinking any U-boats, she helped to drive off their attacks on a number of occasions. She briefly served on the Arctic convoy route to Russia in late 1943, and was part of the naval force escorting the D-Day invasion fleet in June 1944.
Aconite was laid down at Troon in March 1940. In July 1941 she entered service with the Free French and adopted the French version of her name, becoming Aconit.
Aconit would become one of the most famous Free French warships. This was due to her participation in a bitter engagement which began on the night of 10/11 March 1943 and continued into the next day. The North Atlantic convoy HX228, with Aconit among its escort, came under U-boat attack during the night. Aconit was summoned to assist the destroyer HMS Harvester, which had surprised U-444 approaching the convoy on the surface. (Most U-boats were much faster surfaced than submerged, and they often made surface attacks under cover of darkness.) Harvester rammed and crippled the submarine, but in doing so suffered heavy damage herself. When Aconit arrived, she also rammed U-444 and finished her off. She then re-joined the convoy as ordered while Harvester limped along behind, but was called back during the day when the destroyer broke down completely. Meanwhile, another U-boat, U-432, had come on the scene, and in a submerged approach she torpedoed Harvester and sank her. 183 lives were lost. The final duel now commenced as Aconit and U-432 stalked each other. It ended in victory for the French, who forced the submarine to the surface with depth charges and destroyed her with gunfire and rammimg. Aconit then picked up 60 survivors from Harvester. Of the 91 Germans on the two U-boats, 24 were also rescued. Aconit’s battle damage was repaired at Glasgow, and on 21 April 1943 General Charles de Gaulle came aboard her at Greenock, the base for the Free French Atlantic escort force, and presented awards for valour to the ship and her commander, Lieutenant Jean Levasseur.
The second pair of corvettes to be built at Troon were improved Castle Class vessels. Work began on Tintagel Castle in April 1943, and around a year later she entered service with the Royal Navy. On 10 April 1945, along with the destroyer HMS Vanquisher, she depth charged and sank U-878 in the Bay of Biscay – there were no survivors from the submarine’s crew of 51.
Wolvesey Castle was laid down in June 1943, but by the time of her launch in February 1944 she had been earmarked for service with the Royal Canadian Navy, and her name had been changed to Huntsville after a town in Canada. Her active service commenced in August 1944, and by the end of the war she had helped to protect the passage of 14 convoys.
The stop-gap corvettes were followed by larger anti-submarine vessels which were better-armed and more seaworthy. Again, they were given a type name revived from the great days of Nelson – the frigate. Two, Loch Tarbert and Loch Veyatie, were ordered from Ailsa at Troon in early 1943, but their greater degree of sophistication and the unfamiliar pre-fabricated method of construction led to delays. Loch Tarbert eventually became operational with the Royal Navy in mid-April 1945 and commenced convoy escort work, but she saw no combat before the war in Europe ended on 8 May that year. Loch Veyatie was not completed until well after the war had ended.
All of the Troon-built U-boat hunters survived the war. Loch Tarbert, Loch Veyatie and Tintagel Castle were scrapped at the end of their Royal Navy service, the latter vessel returning to Troon in 1958 to be broken up. Huntsville was converted to a merchant ship after the war, and was lost in a collision in 1960. Aconit and Acanthus were also sold for commercial use, and had long careers as whale-catchers before being scrapped, in 1967 and 1970 respectively.
In addition to these escort vessels, eight Bangor class fleet minesweepers were built at Troon during the war for the Royal Navy, of which two were lost in action.