Vital secret on captured U-boat

May 9 1941 — The capture ofGerman submarine U-110by the Royal Navy gives up a vital war tool – her top-secret Enigma machine, used to encrypt and decrypt the secure message traffic of the German armed forces during World War 2, and her code book. U-110 had just two patrols, damaging British ships in March before sinking the Henri Mory (April 27), Bengore Head and Esmond (both on May 9). It is located with sonar by the corvette HMS Aubrietia, which, together with the destroyer HMS Broadway,force U-110 to surface with depth charges. Broadway fires two depth charges beneath the damaged U-boat and the crew abandon ship. A party from the destroyer HMS Bulldog, led by Sub-lieutenant David Balme (inset right), undertakes the dangerous mission to board U-110 and strip it of everything portable. William Stewart Pollock, a former radio operator in the Royal Navy and on loan to Bulldog, retrieves the Enigma and code book as they look out ofplace in the radio room. Capturing the Enigma marks a vital turning point in the Battle of the Atlantic.It plays a significant role in cryptanalysis at Bletchley Park led by Alan Turing. Despite being credited with a capture that turned the tide of the deadliest war ever fought and thus shortening it by two years,Balme doesn’t receive any recognition until the enforced secrecy surrounding Enigma is relaxed in the 1970s.