On approaching the convoy , Douglas rescued 18 survivors from the tanker Capulet , which had been torpedoed by U-552 .
On approaching the convoy , Douglas failed in an attempt to sink Capulet 's abandoned wreck with gunfire .
On approaching the convoy , Douglas rescued 18 survivors from the tanker Capulet , which had been torpedoed by U-552 , but failed in an attempt to sink Capulet 's abandoned wreck with gunfire .