One of the best-kept secrets of World War II

I’m sure many US readers will remember the 2000 film U-571.  It purported to tell the story of how US naval forces recovered the German Enigma code machine from a U-boat.  However, many are not aware that the story was almost entirely fictitious, despite the film being allegedly ‘based on a true story’.  (I suppose that if 95% of it was false, and only 5% was true, that might still be considered ‘based upon fact’ . . . but it’s an awfully big stretch, IMHO!)

Nevertheless, the ‘core’ story of an Enigma being recovered from a U-boat was true.  It was accomplished by a British ship before the USA entered World War II.  The man primarily responsible for the recovery has just died.  From his obituary:

Lieutenant Commander David Balme, who has died aged 95, led a boarding party which captured the secrets of Enigma from a German U-boat during the Battle of Convoy OB138 in May 1941, a turning point in the Battle of the Atlantic.

At midday on May 9 1941 Commander Joe Baker-Cresswell, captain of the destroyer Bulldog, was about to order the ships of the 3rd Escort Group to leave west-bound trans-Atlantic Convoy OB318 in order to refuel at Iceland, when two merchant ships were torpedoed in quick succession. The torpedoes were fired from U-110, commanded by the U-boat ace Fritz-Julius Lemp, who failed to notice the proximity of the corvette Aubretia. Before his second salvo of torpedoes struck, Aubretia’s Lieutenant Commander Vivian Smith commenced a counter-attack with depth charges which blew U-110 to the surface.

The destroyer Broadway attempted to ram the surfaced U-boat and all three British ships opened fire with their guns. There was panic in U-110 and the crew abandoned ship: 15 men were killed or drowned including Lemp, and 32 survivors were picked up and hurried below deck in Aubretia. The action was over in minutes, and when Baker-Cresswell stopped Bulldog alongside the U-boat he found it wallowing stern-down in the Atlantic rollers.

U-110 and HMS Bulldog (image courtesy of Wikipedia)

Balme was ordered to row across in Bulldog’s whaler to “get whatever you can out of her – documents, books, charts, and get the wireless settings, anything like that”. Jumping on to the U-boat’s outer hull he walked, revolver in hand, to the conning tower, at which point he had to holster his pistol in order to climb three ladders to the top of the tower and down again inside the U-boat to the control room. It was, he later recalled, “a very nasty moment because both my hands were occupied and I was a sitting target to anyone down below”.

Balme was very frightened; he expected the boat to sink, or scuttling charges to blow up at any moment, or to be overcome by chlorine from damaged batteries. The inside of the boat was dimly lit, there was a “nasty” hissing noise, and he could hear water slopping in the bilges. “I immediately went right for’d and right aft with my revolver in my hand to see if there was anybody about,” he said later. Noting that despite damage the U-boat was clean and well-kept and there was food on the table, but finding no Germans aboard, Balme called down the boarding party and “started ransacking all the treasures of the U-boat”.

In the wireless office, telegraphist Alan Long found “a funny sort of instrument, Sir, it looks like a typewriter but when you press the keys something else comes up on it”. Balme recognised this as “some sort of coding machine”, which he ordered to be unscrewed, and he organised a human chain to carry the machine and other equipment, charts and documents up the ladders and into the whaler.

Balme and Long had found an Enigma machine, the cipher device which the German U-boat service used to communicate to its fleet in, as the Germans thought, an unbreakable code. Besides that day’s settings they also recovered the daily settings until the end of June, which, when delivered later to Bletchley Park, enabled Alan Turing and his team to read the German naval “Hydra” code, the officer-only code, and, with the knowledge and experience gained, to go on to crack several other codes. Lemp’s crew were so demoralised and ill-disciplined that later in prison camp they talked freely to their interrogators about U-110 and about other boats in which they had served.

Balme and his men spent six hours inside U-110, where for some time they were left alone in the Atlantic, listening to the distant sound of depth charges while the 3rd Escort Group hunted another U-boat. When Bulldog returned, Balme passed a towline, and for a day U-110 was pulled towards Iceland, until about 11.00 on May 10 1941 when the German vessel reared its bows in the air and sank stern-first.

The loss of U-110 enabled the British to throw a cloak of secrecy over the whole affair, a cloak so dark that even when Captain Stephen Roskill, the official historian of the Royal Navy, wrote about the capture in 1959, only those already in the know were able to read between the lines and would have realised that the secret of the capture was not the U-boat but the Enigma material which was salvaged from it. Balme had been told that the truth of his secret capture would be kept forever, and was surprised when in the 1970s its secrets began to leak out.

Baker-Cresswell and Smith were awarded the DSO, Balme the DSC, and Long the DSM, for enterprise and skill in action against enemy submarines.

There were also breaches of security: Baker-Cresswell had told Balme to bring him back a pair of binoculars. Balme brought back two, and he used these swastika-stamped Zeiss binoculars in his yacht for 50 years. He also pinched Lemp’s cap from his cabin, keeping it as a souvenir until he presented it to the Imperial War Museum in 2003.

There’s more at the link.

The capture of U-110 was subsequently named Operation Primrose by the Royal Navy, and kept top secret for several months.  Security precautions included failing to notify the Germans of the death of some of its crew and the capture of others, as required under international convention.  Only when the authorities were sure that U-110’s crew did not suspect that their ship had been temporarily captured rather than immediately sunk, and therefore could not reveal the loss of the Enigma machine, did they allow news of their fate to reach their families.

Notwithstanding Hollywood’s fictional excesses, there is an American link to the capture of U-110.  HMS Broadway, one of the destroyers involved in the action, was originally the World War I-vintage Clemson class ‘four-piper’ destroyer USS Hunt.  She was one of fifty old destroyers transferred to Britain in 1940 in the so-called ‘Destroyers for Bases Agreement‘.  She was scrapped shortly after the end of World War II.



  1. And don't forget the last capture of a foreign warship on the high seas, the U 505 by Dan Gallery, and the USS Guadalcanal. Not only did we get the codes and machine, we got the whole U boat. It is on display in Chicago.

  2. Wasn't there also a movie about how we Americans saved the day with the raid on the heavy water place in Norway?
    Except I think it was the British who did that.
    You'd think that we do enough good things that we wouldn't need to steal credit for things we didn't do, but then this is Hollywood we're talking about…

  3. Just because the Guadalcanal was a "Jeep Carrier", it didn't have to live up to its name by pulling into port with the 505 strapped across its hood…

  4. Much more on the Enigma by David Kahn in his two books, The Codebreakers and Seizing the Enigma. Dan Gallery's book about the Guadalcanal's adventures, including capture of the U-505 is Clear the Decks.

    As an FYI, the Poles had built an Enigma from scratch based on their decoding efforts directed toward cracking German codes, and just before the German invasion of Poland provided one to the British.

  5. Actually the movie on Enigma closest to reality is "The Imitation Game" about Alan Turing's life (although still prone to "artistic licentiousness").

  6. The stories about Enigma abound because of the secrecy during WW II. The plans for the machine were sent to Great Brittan via the Swedish Embassy prior to the start of the war. An actual machine was captured at the start of the war along with the current code books when a U Boat grounded itself trying to get a look see on the western shores of England. The German crew were captured and isolated to prevent German intelligence realizing the compromised material.

    Unfortunately, I can't give the source data because the books were in the main Chicago public library and were thrown out years ago. In the early 60s the library had oodles of personal accounts of code breakers from the Spanish American War through WW II. Now they are all gone and those true first hand accounts are lost.


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