Convoy TM 1 Convoy TM 1 was the code name for an Allied convoy during the Second World War . Nine tankers , escorted by Royal Navy warships , attempted to reach Gibraltar from Trinidad . The convoy was attacked by a U - boat wolf pack in the central Atlantic Ocean , and most of the merchant vessels were sunk . This was one of the most successful attacks on Allied supply convoys throughout the entire war . The convoy was defended by the destroyer HMS " Havelock " , and three Flower class corvette s , , and HMS " Saxifrage " . Seven tankers were sunk during the attacks , two surviving to reach Gibraltar . Two U - boats were damaged during the attacks . Battle . " U - 124 " located HMS " Godetia " on 29 December 1942 , escorting two tankers to join up with the main convoy . " U - 514 " made contact with the convoy on 3 January and attacked and damaged the tanker , forcing her crew to abandon her though the ship remained afloat . By now aware that a large tanker convoy was headed through the Atlantic , presumably to deliver supplies to the allied armies in North Africa , Admiral Karl Dönitz , the German BdU ( commander in chief of U - Boats ) ordered wolf pack " Dolphin " to move into the area and attempt to intercept it . " U - 381 " made contact with the convoy on 8 January , and the wolf pack launched their first attacks that evening . " U - 436 " attacked and sank the and damaged the . HMS " Havelock " launched a counter - attack , damaging and driving off " U - 381 " , while " Pimpernel " and " Godetia " drove off " U - 571 " and " U - 575 " respectively . " U - 522 " returned the following morning and attacked the convoy , damaging two tankers , the , and , while " U - 442 " damaged the " Empire Lytton " . " U - 181 " and " U - 134 " made attacks , but failed to hit any targets . " Godetia " retaliated with depth charge s , damaging " U - 134 " . " U - 620 " kept in contact with the convoy , and in the evening of 9 January , " U - 522 " attacked the two tankers she had damaged earlier in the morning , " Norvik " and " Minister Wedel " , and sank both of them . Meanwhile " U - 442 " returned to the damaged and abandoned " Empire Lytton " and finished her off with two torpedoes , while " U - 436 " returned to the abandoned " Albert L . Ellsworth " and sank her with shells from her deck gun . The " U - 511 " came across the , a merchant ship sailing unescorted and not part of convoy TM 1 , and sank her . The attacks resumed on the night of 10 / 11 January , with " U - 522 " torpedoing the . Her crew abandoned her , but the ship was only damaged and did not sink until " U - 620 " arrived and sank her with a " coup - de - grace " torpedo and gunfire . Other attacks that evening and over the next two days , by " U - 571 " and " U - 511 " , fail to score any successes . By now the convoy was approaching Gibraltar , and the destroyer and the corvettes and were sent out to reinforce the escorts . Supported by allied air cover , the convoy reached Gibraltar without further loss on 14 January . Two tankers , the " Cliona " and the " Vanja " , survived from the original nine . The final action came on 24 January , when the abandoned hulk of " British Vigilance " , torpedoed by " U - 514 " on 3 January , was discovered by " U - 105 " , and promptly sunk .