Convoy OB 318

Convoy OB 318. It was a significant North Atlantic convoy of the Second World War that departed from Liverpool in early May 1941. The convoy became the focus of a major engagement with German submarines, resulting in substantial losses for both sides. The battle is noted for the involvement of the Royal Navy's Escort Group B-7 and the loss of the famed U-boat U-110, which led to a critical intelligence coup for the Allies.

Background

The Battle of the Atlantic was reaching a critical phase in early 1941, with Admiral Karl Dönitz's U-boat wolfpack tactics inflicting heavy losses on Allied shipping. Convoys sailing from the British Isles to North America, like those on the OB route, were primary targets. The Admiralty was continuously refining its convoy tactics and escort capabilities in response. The period also saw increased cooperation between the Royal Navy and the Royal Canadian Navy, as well as the introduction of more capable corvettes and destroyers into escort groups.

Ships and escort

The convoy comprised approximately 38 merchant ships, including vessels such as the *Empire Cloud* and the *Bengore Head*. The close escort was provided by the renowned Escort Group B-7, commanded by Commander Donald Macintyre aboard the destroyer HMS *Walker*. The group included the destroyer HMS *Vanoc* and several Flower-class corvettes like HMS *Bluebell*. Additional support was available from the Home Fleet and a separate ocean escort group.

U-boat attacks

On 7 May, the convoy was detected by *U-94* under Kapitänleutnant Herbert Kuppisch, which summoned a wolfpack. The first attacks began that night, with *U-94* sinking the *Ixion*. On 9 May, *U-201* (Adalbert Schnee) and *U-556* (Herbert Wohlfarth) joined the assault, sinking several ships including the *Gregalia* and *Aelybryn*. The critical moment occurred when *U-110*, commanded by Fritz-Julius Lemp, was depth-charged and forced to the surface by *HMS *Aubretia*** and attacked by *HMS *Bulldog*** and *HMS *Broadway***. Lemp ordered the crew to abandon ship, believing the U-boat was sinking, but it was captured largely intact.

Aftermath

The capture of *U-110* was one of the greatest intelligence prizes of the war. Royal Navy boarding parties recovered an intact Enigma machine and its associated codebooks from the submarine. This material was delivered to the codebreakers at Bletchley Park, significantly aiding the Ultra intelligence program. While the convoy lost six merchant ships, the Kriegsmarine suffered the loss of *U-110* and severe damage to other submarines. The battle demonstrated the growing effectiveness of Allied Anti-submarine warfare tactics and escort coordination.

Legacy

The engagement is historically significant primarily for the capture of the Enigma machine from *U-110*, an event sometimes referred to as "the most important capture of the war at sea." The intelligence gained provided Bletchley Park with crucial insights into German naval codes, shortening the war in the Atlantic. The tactics used by Escort Group B-7 under Macintyre became a model for future escort operations. The battle is studied as a key example of the turning point in the Battle of the Atlantic during mid-1941, preceding even more decisive Allied victories later in the year.

Category:Naval battles of World War II involving the United Kingdom Category:Convoys of World War II Category:Battle of the Atlantic