“AS BALME’S MEN SEARCHED THE ABANDONED SUBMARINE, THEY FOUND NOT ONLY THE U-BOAT’S CODEBOOK BUT AN INTACT ENIGMA MACHINE” On 9 May 1941, U-boat ace Fritz-Julius Lemp, commander of U-110, attacked a convoy just south of Iceland. He hit two ships before being spotted by the British destroyer HMS Bulldog, which turned and raced towards him. Lemp, realising the danger, dived, but it was too late. The Bulldog was soon on top of him, and he and his crew could hear depth charges crashing into the water.
Lemp’s crew knew what was coming, and waited in agonising silence for the inevitable shockwaves from the explosions. When they came, they were horrific. “The vibrations were so bad,” Georg Högel, Lemp’s then 21-year-old radio operator, later recalled, “that we knew we couldn’t…
