Convoy SC 48 - Prelude

Prelude

SC 48 was an east-bound convoy of 52 ships, carrying war materials and sailed from Sydney, Cape Breton on 5 October 1941 bound for Liverpool. It was under the command of Commodore HM Sanders in the MV Castalia.

It was escorted by a Canadian escort group consisting of the destroyer HMCS Columbia (Lt Cdr SW Davis as Senior Officer Escort), and seven corvettes; HMCS Wetaskiwin, HMCS Rosthern, HMCS Baddeck, HMCS Camrose, HMCS Shediac, HMS Gladiolus and the Free French Mimosa.

Opposing this force was the patrol line Mordbrenner, which was to have comprised eight U-boats and was in the process of forming south of Iceland near the Mid-Ocean Meeting Point. This was the point at which North Atlantic convoys were handed over between the Ocean and the Western Approaches escorts at this stage of the Atlantic campaign.

Allied intelligence became aware of the presence of Mordbrenner, and started to divert the convoys then at sea, but a loss of Ultra intelligence on 12/13 October left SC 48 in the dark; and on the night of 14/15 October it was sighted by U-553 (K/L Karl Thurmann).

At this point in time SC 48 was in some disarray; 11 of its ships, including Castalia, were straggling following heavy weather on the night of 9/10 October. Columbia and two of the corvettes, Camrose and Rosthern, were detached looking for them. A third corvette, Shediac was also separated by the storm and out of radio contact. On 14 October SC 48’s escort comprised just four corvettes; Wetaskiwin (as Acting SOE), Baddeck, Gladiolus and Mimosa.