Enigma machine captured

9th May 1941: A young naval officer forces his way onto a sinking U-boat - and changes the course of the entire war

The boarding party led by Sub-Lieutenant David Balme climbs onto the U-110, as seen from HMS Bulldog, soon after midday on 9th May. Balme had to holster his revolver in order to undo two hatches and climb down into the U-boat. It was only then realised that the entire crew had abandoned ship.

The original image, showing the distance from HMS Bulldog to U-110.

One of the outstanding intelligence breakthroughs of the war came on 9th May with the capture of an intact Enigma machine, the German encoding device that they had believed was impossible to break. When awarding a medal to the officer responsible, the King told him it was “perhaps the most important single event in the whole war at sea.”

… perhaps the most important single event in the whole war at sea.

The British had assembled a team of brilliant academics at Bletchley Park who were making steady progress in deciphering German messages encoded with ‘Enigma’ machines. They already possessed one Enigma machine, passed on by Polish Intelligence before the war. What was needed were the internal rotors from the machines currently in use. A number of schemes had been devised to capture these, including one worthy of James Bond, but the boarding of U-110 came as an unexpected bonus.

The U-boat had been forced to surface after depth-charging, and the crew had abandoned ship, believing that the U-boat was already sinking, or that, by opening the sea cocks, she would soon. The surviving crew were rescued and quickly taken below decks so they would not be aware that the U-boat was being boarded.

Fritz-Julius Lemp, commander of U-110, with Admiral Donitz, Befehlshaber der Unterseeboote, commander of the U-boat arm. Lemp had sunk the passenger liner Athenia on the first day of the war, contrary to the rules of war, killing American and Canadian children. The Nazis tried to cover up the fact that they were responsible.

The commander of the U-boat Lemp died; some accounts from the German crew suggested he was shot as he attempted to swim back to the boat to sink her. But the Royal Navy officers involved denied this, and it is more likely that he drowned accidentally or by suicide when he realised the enormity of his failure to scuttle his boat. Fourteen other crew members died from the cold and exhaustion of abandoning the U-boat, or from wounds.

The Captain of HMS Bulldog reported:

H.M.S. Bulldog stopped within 100 yards of the submarine and sent away an armed whaler’s crew. No sign of a white flag was seen and two men appeared to be manning the submarine’s forward gun. Fire was again opened by Lewis gun and two or three men were hit. My object was to keep the crew rattled. They already appeared dazed and uncertain what to do. By the time the whaler was alongside the submarine, the whole crew appeared to have jumped into the water.

There was a moderate sea running and waves were breaking over the U. boat’s deck. The officer in charge of the whaler, appreciating the necessity of speed, ran his boat hard on board the submarine and a wave carried it on to the deck where it was smashed. The crew found that the conning tower hatch was closed. They opened it and went below without delay. ( Their orders were to seize all books and anything that looked important). Shortly afterwards they signaled that the U. boat had been abandoned, and appeared to be sound and in no danger of sinking.

The twenty-year-old David Balme (1920-2016) was awarded the Distinguished Service Cross and later became the youngest Lieutenant Commander in the Royal Navy.

Sub-Lieutenant David Balme reported how he boarded U-110: