Convoy OB 318

Date	7–10 May 1941
Location	Atlantic Ocean, South of Iceland
Result	British victory

Belligerents

United Kingdom

Germany

Commanders and leaders

Convoy Commodore: WB MacKenzie RNR
Escort: Cdr AJB Baker-Cresswell
Boarding Party: Sub-Lt. David Balme

Admiral Karl Dönitz

Strength

40 freighters
3 Destroyers
3 Corvettes
2 Naval trawlers

4 submarines

Casualties and losses

7 freighters sunk (35,315GRT)
40 killed/drowned
2 freighters damaged

1 submarine captured
14 killed/drowned
32 captured
2 submarines damaged

OB 318 was a North Atlantic convoy which ran during the Battle of the Atlantic in World War II. During Operation Primrose Royal Navy convoy escorts HMS Bulldog, Broadway and Aubretia captured U-110 with an intact Enigma machine and a wealth of signals intelligence, which led to the Allied breakthrough into cracking the German naval Enigma code.

By the Spring of 1941 the battle of the Atlantic was starting to have an increase in German U-boat losses. This forced Vizeadmiral Karl Dönitz to change his strategy and he now moved his wolf packs further west, in order to catch the convoys without their anti-submarine escort. OB 318 was a west-bound convoy of 38 ships, either in ballast or carrying trade goods, and sailed from Liverpool on 2 May 1941 bound for ports in North America. The convoy commodore was R.Adm. WB MacKenzie in SS Colonial. It was escorted by 7 EG, an escort group led by HMS Westcott (Cdr. Bockett-Pugh) and comprising ten warships; these were joined in mid-ocean by 3 EG, a force of eight warships led by HMS Bulldog (Cdr J Baker-Cresswell). Opposing them was a force of nineteen U-boats, though in the event only six were in a position to pose a threat. One of those was U-110 under the command of Kapitänleutnant Fritz-Julius Lemp. Lemp notoriously had been in command of U-30 in 1939 which had controversially sunk the 13,581 ton passenger ship Athenia.

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Wikipedia