Order of battle for Convoy SC 7

Convoy SC 7 was the seventh of the SC convoys, bound from Sydney, Nova Scotia across the North Atlantic to British ports, mainly Liverpool. They were called SC as their departure point was designated Sydney, Cape Breton to avoid confusion with Sydney in Australia. The convoys formed part of the battle of the Atlantic during the Second World War. Large numbers of merchant ships travelled with naval escorts to protect against U-boat attacks. Th convoys were often slow, the merchantmen often only being capable of a speed of around 8 kn and so were particularly vulnerable to attack. This problem was exacerbated by a shortage of suitable escorts from either the Royal Canadian Navy or the Royal Navy early in the war.

Convoy SC 7 left Sydney on 5 October 1940, consisting of 36 freighters initially escorted by the Canadian armed yacht HMCS Elk (S05) and the British sloop HMS Scarborough (U25). Having seen the convoy out of Canadian waters, Elk turned back on 7 October, leaving the convoy to spend three-quarters of the crossing escorted by Scarborough. SS Winona had developed engine problems and also turned back. The crossing was uneventful, the only casualty being SS Trevisa, which straggled behind the convoy and was torpedoed and sunk near Rockall on 16 October by GS U-124 (1940).

The main convoy was spotted the following day by GS U-38 (1938), which sank SS Aenos (1910). Further sporadic attacks continued that day and the following, despite the arrival of the sloop HMS Fowey (L15) and the corvette HMS Bluebell (K80). The night of 18/19 October saw the use of the wolf pack tactic by the U-boats. Five U-boats; GS U-46 (1938), GS U-99 (1940), GS U-100 (1939), GS U-101 (1940) and GS U-123 (1940) attacked together, overwhelming the escorts, despite being reinforced by HMS Leith (U36) and HMS Heartsease (K15). They sank 16 ships in a six-hours, bringing the total to twenty freighters sunk and a total tonnage lost of 79,592 gross registered tons. The U-boats only broke off their attacks to intercept convoy HX 79, which had arrived in the area. They went on to sink a further 12 ships from this convoy, for a total of 28 ships sunk on 18/19 October, making this the deadliest two days of the battle of the Atlantic. The surviving merchant ships were gathered up by the remaining escorts and brought into port several days later.