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You are here: Home / Article topics / Publications / Naval Historical Review / The Battle of the Atlantic – Contribution by Code Breakers

The Battle of the Atlantic – Contribution by Code Breakers

Keegan, John · Mar 4, 2007 · Print This Page

Author
Keegan, John
Subjects
Naval Intelligence, WWII operations, History - WW2
Tags
U Boat, Atlantic, Bletchley Park, code breaking, Enigma
RAN Ships
None noted.
Publication
March 2007 edition of the Naval Historical Review (all rights reserved)

Paradoxically, however, during what historians of the U-boat war denote as ‘the great convoy battles’ in the first five months of 1943, the British were frequently reading Enigma in real time and the Trade Division was redirecting some convoys away from U‑boat patrol lines. Moreover, although there were massacres, U-boat losses were also rising, eventually to unbearable levels, forcing Doenitz, in May 1943, to take his boats out of the North Atlantic and so, effectively, admit defeat.

What, therefore, are we to make of E. H. Hinsley’s assertion that Bletchley achieved one of its undeniable successes in the Atlantic battle? Hinsley, a Bletchley veteran, is notably modest in the claims he makes for the British Government Code and Cipher School. He specifically rejects the view that ‘Bletchley won the war’, and rightly so. His estimate of Bletchley’s success in the war against the U-boats must be set, however, against Clay Blair’s sober and heavily documented assessment that over 99 per cent of all ships forming transatlantic convoys reached their destinations safely. Out of 43,526 ships sailed (many several times, of course), 272 were sunk by U-boats. Many others were sunk but usually when sailing independently or having left convoys, either to ‘straggle’ (fall behind) or to ‘romp’ (sail ahead).

Counting the Cost

Allied merchant seamen paid a terrible price. Over 30,000 out of 120,000 in the British Merchant Navy alone were killed in the struggle against the U-boats. The U-boat crews, however, suffered worse: 28,000, out of an enlisted force of 40,000, died in the destruction of their submarines – which amounted to 713. Aircraft sank 204, warships 240, aircraft flying from escort carriers 39; ships and aircraft operating together sank 84; mines, accidents and other incidents – such as U-boats ramming each other – made up the difference in numbers.

The outcome of the Atlantic battle, seen in perspective, suggests that intelligence, as in so many other operational circumstances, was, though significant, secondary to the age-old business of fighting the issue out. In easy times, as during the U-boat’s ‘Happy Time’ along the eastern American seaboard in the first six months of 1942, it was not strategic intelligence but day-to-day happen-stance that yielded the victims. In the more difficult times, particularly during the ‘great convoy battles’ of early 1943, Bletchley’s ability to steer convoys out of danger frustrated many of the traps Doenitz laid, but it was the stolid endurance of the merchant seamen, sticking to convoy commodores’ orders, and the dogged determination of the escort crews to fight back, that did the U-boats down. Modern interpretations of the Battle of the Atlantic represent it as a true battle, in which one side attacked, the other accepted the challenge to defend or counter-attack, and counter-attack prevailed. That seems correct. The Battle of the Atlantic could have been won without the assistance of the code-breakers, greatly though they helped to tip the balance in the favour of the defenders.

Pages: Page 1 Page 2

Naval Historical Review, Naval Intelligence, WWII operations, History - WW2 U Boat, Atlantic, Bletchley Park, code breaking, Enigma

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