Built at the William Denny and Sons shipyard in Dumbarton the steel steamship St Briac measured 316.0′ x 41.1′ x 13.9′ and weighed 2,312 gross tons, 938 net tons. Launched in 1924 her Denny steam turbine engines generated 969 nhp. She was ownded by the Southern Railway Company Limited and registered in Southhampton.
The St Briac, named after a commune in Brittany, France, was built to operate on the Southampton to St Malo route ferrying passengers back and forth on this important link between Britain and Europe. She could carry up to 1300 passengers and had 450 sleeping berths aboard. She operated successfully on this route for fifteen years until the outbreak of World War Two. In the summer of 1940 she participated in Operation Dynamo, the successful evacuation of allied troops from the beaches at Dunkirk. She was subsequently requisitioned as a Merchant Auxiliary to be used by the Fleet Air Arm based at Arbroath. She was often used in Fleet Air Arm target practice both as a target vessel and for towing other targets.
HMS St Briac left Dundee on the morning of 12th March 1940 on her usual duties. A successful shadow exercise was completed with planes out from Arbroath between 10:00am and 12:00 noon. On completion of the first exercise a new course was set to reach the area for a planned search exercise that afternoon due to begin at 15:00. However, at 14:05 with the captain examining his charts in the Chart House, the ship was rocked by a huge explosion as she collided with an unseen mine. The explosion happened under the starboard side near the engine room and within minutes the engine room was flooded and the engines failed. The stokehold bulkheads held stopping the ship from sinking instantly but she was slowly settling by the stern. She was helpless in a strong south easterly gale drifting in a British minefield laid to protect the vital shipping lane along the east coast of Scotland. Captain Lubbock still hoped his ship might be saved but, recognising their perilous position, immediately ordered distress signals to be sent out.
Four armed trawlers and the Arbroath and Montrose lifeboats were immediately dispatched to the scene. Captain Lubbock ordered all the lifeboats lowered as a precaution and unfortunately, with the powerless ship lurching and rolling in the heavy swell, one of them was damaged beyond repair as it was lowered to the surface. With the ship slowly sinking beneath them the crew were ordered to board the lifeboats but, at around 14:25 as this order was being carried out, the St Briac collided with another mine midships and broke her back only three minutes later and began the plunge to the seabed. Two lifeboats were safely away from the sinking ship but the whaler, with Captain Lubbeck and a number other of the crewmen aboard, capsized and the occupants were thrown in to the sea. Lubbeck surfaced in time to see the bow of his ship rise into the air and sink beneath the surface. It was only five minutes since the second explosion. He and three other seamen from the whaler clung grimly to some floating wreckage and were soon picked up by one of the lifeboats. This boat, with twenty seven men now aboard, was spotted by a patrolling Swordfish biplane the following morning. The pilot reported their position allowing the tug Empire Larch to reach their position and safely pick up the men aboard. The second lifeboat was not so lucky. This boat had drifted north and east towards the shore at Collieston. With safety in sight the lifeboat capsized in heavy seas and thirteen of the seventeen occupants were drowned. 47 men had lost their lives as the St Briac was lost.
The wreck of the St Briac lies in position 56°33.045’N, 001°33.690’W (WGS84) in 58 metres of water. The wreck is in two pieces which lie close together and is oriented 145°/325°. The stern section is fairly in tact and sits upright with some of her stern superstructure still in place. The stern gun mounting, with cases of live ammunition close by, is empty as it appears that the gun itself was torn from its mounts as she sank and lies somewhere nearby on the seabed. Midships the wreck is very broken as a result of the two explosions which caused her demise. The engine and boilers are clearly visible. The bow section is lying on it’s port side and is also still fairly in tact.