Convoy SC 94 Convoy SC - 94 was the 94th of the numbered series of World War II Slow Convoys of merchant ships from Sydney , Cape Breton Island , Nova Scotia , to Liverpool . The ships departed Sydney on 31 July 1942 and were met by Mid - Ocean Escort Force Group C - 1 consisting of the Canadian River class destroyer " Assiniboine " with the Flower class corvette s " Battleford " , " Chilliwack " , " Dianthus " , " Nasturtium " , " Orillia " , and " Primrose " . Background . As western Atlantic coastal convoys brought an end to the second happy time , Admiral Karl Dönitz , the " Befehlshaber der U - Boote " ( " BdU " ) or commander in chief of U - Boats , shifted focus to the mid - Atlantic to avoid aircraft patrols . Although convoy routing was less predictable in the mid - ocean , Dönitz anticipated that the increased numbers of U - boats being produced would be able to effectively search the area with the advantage of intelligence gained through " B - Dienst " decryption of British Naval Cypher Number 3 . However , only 20 percent of the 180 trans - Atlantic convoys sailing from the end of July 1942 until the end of April 1943 lost ships to U - boat attack . Discovery on 5 August . " U - 593 " reported the convoy on 5 August and torpedoed the Dutch freighter " Spar " . Attack of 6 August . " Assiniboine " s Type 286 radar spotted in a heavy fog on 6 August . The destroyer closed on the contact and briefly spotted the submarine twice before losing her in the fog . The submarine reappeared crossing the destroyer ' s bow at a range of , and both ships opened fire . The range was too close for " Assiniboine " s 4 . 7 - inch guns to engage , but her . 50 - calibre machine guns shot up the submarine ' s deck and conning tower . This kept the Germans from manning their deck gun , but the flak gun was already manned and firing . It punched holes through the destroyer ' s plating that set some petrol tanks on the deck afire and disabled ' A ' gun . The destroyer was unable to ram " U - 210 " until the rear 4 . 7 - inch gun hit the conning tower , killing the entire bridge crew and the . 50 - caliber machine guns were able to silence the flak gun . This caused Lieutenant Sorber , the senior surviving officer , to order the submarine to dive , but this meant that she had to hold a straight course while doing so . " Assiniboine " was able to take advantage of this and rammed " U - 210 " abaft the conning tower whilst she was diving . This caused the electric motors to fail , damaged her propellers and led to water entering the submarine , as a result of which Sorber ordered the ballast tank s to be blown and the submarine to be abandoned . The destroyer rammed her again when " U - 210 " resurfaced , dropped a pattern of depth charges set to detonate at shallow depth and hit her one more time with a 4 . 7 - inch shell before the submarine finally sank . Attack of 8 August . " U - 379 " torpedoed the British freighter " Anneberg " and American freighter " Kaimoku " on the afternoon of 8 August while " U - 176 " torpedoed the British freighters " Kelso " and " Trehata " and Greek freighter " Mount Kassion " . Three undamaged ships were abandoned in the resulting panic . One of them , the British freighter " Radchurch " , was later torpedoed by " U - 176 " . The Thornycroft type flotilla leader " Broke " and the Polish destroyer " Blyskawica " arrived to reinforce the escort as " Dianthus " left the convoy to repair damage incurred while ramming and sinking " U - 379 " . Attack of 10 August . " U - 438 " torpedoed the Greek freighter " Condylis " in daylight on 10 August while " U - 660 " torpedoed the British freighters " Cape Race " , " Empire Reindeer " and " Oregon " . The remainder of the convoy reached Liverpool on 13 August .