The tide turns in the Atlantic for the Allies

Eighty years ago the Battle for the Atlantic shifted in favour of the Allies after many years of increasing losses to the U-Boat Wolfpacks.

Photo: © IWM (A 4586)

1943 had started very badly for Allied shipping. With Britain reliant on imports of food and raw materials to survive and supply the war effort any loss was acutely felt and threatened the build-up of personnel and equipment crossing the Atlantic for the second front.

The underlying problem had been the ‘mid-Atlantic Gap’, the section where no long-range air cover was possible. Enigma decrypts when available helped establish where the U-Boats potentially were, but German signals intelligence units on the Continent were also receiving convoy transmissions and relaying the information to the Wolfpacks and long-range patrol aircraft.

Photo: © IWM (A 5668)

The Arctic convoys also suffered, their route being constantly under threat from patrolling U-Boats, the Luftwaffe bases along the Norwegian coast and the ever-present threat of the Scharnhorst and Kriegsmarine cruisers anchored in the Norwegian fjords.

Convoy PQ17 to Murmansk was the nadir with two-thirds of that Arctic convoy lost in transit due to enemy action in late June/early July 1942. Things looked dire.

The turning point came remarkably quickly and by May 1943, the battle was very much in the Allies’ favour. This was due to the longer-ranged B-24 Liberators closing the Atlantic Gap and new centimetric radar which allowed the B-24s and convoy escorts to hunt the U-Boats in bad weather. One example was a radar-equipped escort locating a surfaced U-Boat running off its side in fog, which it quickly rammed and sunk.

B-24 Liberator anti-submarine conversion with rear fuselage, wing and nose search radar antennas and under nose 20 mm cannon pack. © IWM ATP 9767C

The Bay of Biscay also became a hunting ground for U-Boats entering and leaving their home ports, meaning they had to spend more time submerged increasing the transit time to their patrol areas if they survived the aerial attacks and running the gauntlet again on return.

As the year ground on, the U-Boat losses outnumbered those being built with production slowed by increasing Allied bombing and a flawed mass-production plan introduced by the Nazi Armaments Minister Albert Speer.

The harsh realities of naval warfare meant the sea was the grave for those lost, their battles far over the horizon while only their names remained. CWGC remembers the names of the Commonwealth naval personnel and Merchant Marine lost throughout the Atlantic and Arctic campaigns. 

Their bravery and sacrifice is commemorated on our monuments in the United Kingdom at the Tower Hill Memorial (London) which commemorates the Merchant Marine and Fishing Fleet casualties and at the Chatham, Liverpool, Portsmouth, and Plymouth Naval Memorials.