The assault on Convoy OG 74 was just one of a variety of attacks on merchant shipping this week:
Enemy Attack on Seaborne Trade
During the week under review U-boats have made determined attacks on three convoys. Four ships were torpedoed, three of which are reported sunk, in a homeward bound convoy from Canada off the east coast of Greenland. Three ships were torpedoed in an outward bound convoy which was attacked on two successive nights to the west of Ushant.
A homeward bound convoy from Sierra Leone was attacked three times on two successive nights to the west of the Canaries and four ships were torpedoed, of which three are believed sunk. Details of attacks on these convoys may be incomplete.
Two ships were mined and sunk in the Thames Approaches, and another was damaged off Milford Haven. An Isle of Wight Ferry steamer was sunk by an explosion, presumed to have been caused by a mine, outside Portsmouth harbour; between, twenty and twenty-five persons are missing.
Three ships were damaged by bombing off the East coast, one of which subsequently sank.
A rescue vessel, with survivors from the torpedoed ships in the outward bound convoy previously attacked by U-boats, was bombed and set on fire by Focke-Wulf aircraft when 550 miles north-east of the Azores, and was subsequently sunk by our own gunfire; ninety-nine survivors, twenty of whom were seriously wounded, were picked up, but the master and twenty-nine of the crew are missing. The Focke-Wulf was destroyed by fighter aircraft from the escorting anti-aircraft ship.
It has now been ascertained that fifteen ships (62,662 tons) were sunk and one is missing in the homeward bound convoy attacked by U-boats off Greenland on the 10th and 11th September.
From the Naval Situation Report for the week ending 25th September 1941 as reported to the British War Cabinet, see TNA CAB 66/18/49