 In March 1943 , Duncan carried out sea trials and went to Tobermory to work up . In April she joined Escort Group B @-@ 7 as the Senior Officer 's ship , with Commander Peter Gretton in command at the height of the Battle of the Atlantic . She escorted Convoy ONS @-@ 5 in early May , a major convoy battle which saw the destruction of six U boats for the loss of thirteen ships , although Duncan was forced to withdraw for lack of fuel before the battle was over . Later that month , she escorted Convoy SC @-@ 130 , in which three U @-@ boats were destroyed for the loss of no ships . Duncan continued on North Atlantic escort duty until October 1943 ; on 16 October the ship rescued 15 survivors from U @-@ 470 which had been sunk earlier by an Consolidated B @-@ 24 Liberator bomber of the Royal Air Force . Whilst defending Convoy ON @-@ 207 on 23 October , Duncan , together with the destroyer Vidette and a Liberator of No. 224 Squadron RAF , sank U @-@ 274 . Later the same month , on 29 October , Duncan shared the sinking of U @-@ 282 with Vidette and the corvette Sunflower whilst protecting Convoy ON @-@ 208 . 
