Convoy QS-15 was a trade convoy of merchant ships during the Second World War. It was one of the numbered QS Convoys which travelled from Québec to Sydney. The convoy was attacked in the early weeks of the Battle of the St. Lawrence, in the St. Lawrence River and Gulf of St. Lawrence, when German U-boats were making ad hoc forays deep into Canadian waters. The convoy was found on 6 July 1942 by , which then sank three ships. U-132 was attacked and damaged by the convoy escort ship .
Background
The March 1942 St. Lawrence Conference reviewed plans for Quebec–Sydney (QS) convoys for defence against U-boats in the Gulf of St. Lawrence and the St. Lawrence River and establishing a base at Gaspé, Quebec for the St. Lawrence patrol force, named Gaspé Force. However, by spring 1942 the only deterrent active within the St. Lawrence were air patrols. In early May, the first U-boat arrived in the St. Lawrence, . It entered the Gulf of St. Lawrence and sank two merchant vessels.
Following the attacks, all independent sailings were cancelled and the QS-SQ convoy system was adopted. As a result of merchant ship losses in the Atlantic Ocean, many slow lake freighters, vessels built for shipping on the Great Lakes, had been brought into service supplying St. Lawrence ports. The large number of slow ships prevented the adoption of slow and fast convoys of merchants, making all the convoys uniform in speed at a maximum of .
The had departed its base in France on 10 June. On 13 June, the submarine came under intense attack by an unknown corvette, suffering damage significant enough to be ordered home. However, the submarine's commander, Ernst Vogelsang, insisted that he could continue his mission. Arriving in the St. Lawrence area in mid-June the submarine was then ordered to replenish from one of the German supply submarines off the Atlantic coast. U-132 returned to the St. Lawrence via the Cabot Strait and was directed to attack shipping west of Anticosti Island. U-132 entered the St. Lawrence on 30 June, developing engine problems from the attack by the corvette earlier in the patrol. The submarine continued to patrol, submerging to avoid the Royal Canadian Air Force air cover over the area.
Ships in the convoy
Allied merchant ships
A total of twelve merchant vessels joined the convoy, either at Quebec City or later in the short voyage. The convoy sailing formation was two rows of five followed by one row of two merchant vessels. The entire convoy normally covered in total, but lax station keeping by the merchant vessels led to the convoy spreading over a stretch of water. The convoy's maximum speed was . Anastassios Pateras was carrying trucks, grain and general cargo to the United Kingdom. Hainaut was loaded with general cargo, also bound for the United Kingdom. Dinaric was carrying steel and timber. The convoy commodore, a civilian commander of the merchant vessels, had his flag aboard Fjordheim.
Convoy escort
As with other convoys in the early weeks of the Battle of the St. Lawrence, the escort was a single armed military ship. Drummondville was on its sixth escort mission as part of Gaspé Force, having been one of the five s assigned to the unit in May 1942. All of the missions had been commanded by Drummondvilles commanding officer, Lieutenant J.P. Fraser. Additionally, the convoy was to have air cover provided by Royal Canadian Air Force Canso aircraft operating from the airfield at Gaspé. Their arrival was delayed, as they were already covering convoy SQ-16 transiting the Gulf of St. Lawrence.
Battle
The convoy departed Bic Island in the afternoon of 5 July 1942 heading for Sydney, Nova Scotia. While transiting the St. Lawrence River, a Fairmile motor launch on patrol from Rimouski to Gaspé temporarily joined the convoy to aid Drummondville on forcing the merchant vessels into their places in the convoy. U-132 picked up the convoy at 19:20 off Les Méchins, Quebec on 5 July. However, the commander of U-132 waited until 22:30 to surface and pursue it. QS-15 met the inbound convoy SQ-16 during the night and passed to the south, giving the German submarine captain the "impression of overlapping vessels".