Friday, May 9, 1941 - Allies capture German Enigma machine

[Louis]

British destroyers Bulldog and Broadway and British corvette Aubretia seize German U-boat U-110 with Navy Enigma machine, rotors, handbook, and position codes; U-110 is allowed to sink the next day to conceal the capture.

U-110 being captured by HMS Bulldog, 9 May 1941

"On May 9, British destroyers HMS Bulldog, HMS Broadway, and HMS Aubrietia attacked U-110, embarking on what was later called Operation Primrose. The U-boat was seriously damaged and its crew surrendered when it was thought to be sinking. Fifteen men from the boat were killed and 32 were captured. The capture of the U-110 was successfully kept a secret as the boat sunk the next day. The Germans continued to use their codes, assuming their confidential material sank as well.

The recovered materials were taken to Bletchley Park in England, where cryptographers, including computer pioneer Alan Turing, succeeded in breaking the naval code. The codes allowed the U-boat traffic to be read for several weeks, until the keys ran out. Throughout 1941, the British were able to plot the positions of U-boat patrol lines and route convoys around them. Merchant ship losses dropped by over two-thirds in July 1941, and remained low until November. The codes also allowed the British to become familiar with the messages which helped in breaking the new keys".-

 

[Louis]

"David Balme will be forever known as the 20-year-old hero who, on 9 May 1941, boarded a German U-boat in mid-Atlantic, and captured one of the greatest secrets of the WW2. This capture – or ‘pinch’ as it was known within secret, inner circles – changed the course of the Battle of the Atlantic and shortened the war itself.

Balme was part of a team comprising officers and men of the Third Escort Group ably led by Commander Joe Baker Cresswell, also commander of HMS Bulldog, who shared the danger with other unsung heroes such as Lieutenant Commander George Dodds. Balme was tasked with taking the Bulldog’s whaler and a small party to board the U-boat U-110 which had been disabled. However he was alone when initially boarding, entering and searching the U-boat. This put him in a vulnerable position while descending into the vessel - he risked being shot by any German submariner that may have remained or blown-up by a booby-trap device. Furthermore he could have drowned when Bulldog disappeared into the mists of the Atlantic to hunt another U-boat, as U-110 could have plummeted into the depths at any time.

However, where others tried and failed or tragically lost their lives, Balme and his boarding party succeeded magnificently in capturing an entire Enigma machine, the essential rotors and months’ worth of associated cipher material. This was an absolute gift to the code breakers at Bletchley Park who were able to read all the secret German naval signal traffic for some months and it enabled them to read virtually the whole of the traffic for the rest of the war and with little delay. The capture was kept so secret that few even on the British side knew about it – not even the Americans were told what had been achieved after they entered the war. Balme returned from the war and never spoke about the secret capture which he believed would be hidden forever".

Lt Commander David Balme, born Oct 1 1920, died Jan 3 2016