OB 318 was sighted on 7 May 1941 by , which reported its position and commenced shadowing while U-boat Command (
BdU) alerted other U-boats in the area. There were six U-boats within striking distance, and these were ordered to close with
U-94s position. Meanwhile, during 7 May the escort force was joined by five ships from
Iceland and the destroyers of 3 EG, which were to take over escort duties from the
Western Approaches to a dispersal point at 34 West, a location south of
Greenland. Three ships and the destroyers of 7 EG left for Iceland during 7 May, leaving the escort force still at ten warships.
Aubrietia gave the alert to other ships while she unloaded and dropped a pattern of depth charges.
U-110 performed a deep dive and managed to survive the initial onslaught.
Aubrietia was joined by the destroyers
Bulldog and
Broadway, and the attack was delivered with such force that Lemp was forced to surface. As he came up a dozen men on
U-110 rushed to man the guns but were shot by the waiting British ships. Lemp also saw that
Bulldog was preparing to ram so Lemp gave the hurried order to abandon ship. Commander Joe Baker-Cresswell decided to try to capture the U-boat instead and hove to. The survivors went over the side including Lemp. It turned out that Lemp realising that
Bulldog was not going to ram had decided to go back and try to destroy the equipment along with the code books but he failed and died in the attempt.
U-110 itself survived the attack, but was seriously damaged and was taking on water.
U-556 In the early hours of 10 May OB 318 was found by , which attacked immediately, resulting in one ship damaged. As OB 318 was at its dispersal point, the convoy separated during the night, while the escorts departed to meet their next charge. However
U-556 was able to keep in touch with a group of ships heading south-west, and during the day sank two more. ==Aftermath and significance==