Into the Flooded U-559

On 30 October 1942, a British Sunderland flying boat spotted the German submarine U-559 in the Mediterranean. HMS Petard, HMS Pakenham, HMS Hero, HMS Dulverton and HMS Hurworth moved in. A Vickers Wellesley bomber dropped depth charges, and the destroyers attacked for hours. Damaged and unable to remain submerged, U-559 surfaced at about 22:40. Its crew had opened sea valves and petcocks before abandoning ship; 38 survived, while seven died.

HMS Petard called for volunteers to search the submarine. Lieutenant Anthony Fasson and Able Seaman Colin Grazier swam across. Sixteen-year-old NAAFI canteen assistant Tommy Brown joined them. They climbed aboard the sinking boat and searched for documents. Fasson and Grazier worked inside, passing material to Brown, who waited above and carried it to the destroyer’s whaler. The submarine lurched and went under without warning. Fasson and Grazier were drowned. Brown survived.

The men had recovered codebooks from the commander’s cabin of the flooding submarine. They included a Short Weather Cipher and a Short Signal Book. The material mattered because Atlantic U-boats had switched to a four-rotor Enigma in February 1942, leaving Bletchley Park unable to read their messages. The captured books helped the codebreakers resume reading U-boat traffic. The code, known as Shark, was solved at Bletchley Park on 13 December 1942. The recovered information let the Allies reroute convoys away from U-boat positions.

Fasson and Grazier were posthumously awarded the George Cross; Brown received the George Medal. The operation remained secret for decades. The men’s work had taken place in the cramped, filling spaces of a submarine that was already sinking, and the two men had stayed below until it was too late to escape. Their recovered books reached Bletchley Park; their bodies were never recovered.