The Petard Pinch exhibition - Now open to visitors

Seamen’s heroic act to capture codebooks from sinking U-boat

The Petard Pinch in Hut 8 at Bletchley Park is now open to all Bletchley Park visitors, following a preview for the Friends of Bletchley Park yesterday (Sunday 13 December).

This exhibition tells the incredible story of the capture of crucial Enigma codebooks. These enabled Bletchley Park to break back into the German naval Enigma network codenamed Shark, following a devastating ten-month blackout. The Admiralty could then re-route vital convoys coming in from the USA, saving thousands of tons of shipping and countless lives.

On 30 October 1942, Lt Tony Fasson and Able Seaman Colin Grazier, along with NAAFI canteen assistant Tommy Brown, made their way towards the stricken U-559, which was sinking after being hit by depth charges for ten hours.

While the U-boat was gradually filling with water, Fasson and Grazier boarded the submarine and handed various Enigma ‘treasures’ to Brown on the U-boat’s conning tower.

The U-Boat sank, taking Fasson and Grazier with it, while Brown was rescued by the crew. Their bodies were never recovered.

The demand for intelligence was never more closely linked to heroic sacrifice but Fasson and Grazier did not die in vain. Just three weeks later the vital documents taken from the U-559 arrived at Bletchley Park. On 13 December 1942, Hut 8 broke back into Shark, unlocking vital intelligence about the U-Boats’ movements.

Bletchley Park’s Research Historian, Dr David Kenyon, says “The achievements of the crew of HMS Petard in October 1942 were vital to the Allies' success in the war at sea. The documents they captured allowed Bletchley Park to read German U-Boat codes for the first time in nearly a year, and to continue to do so for the remainder of the war. As a direct result the Battle of the Atlantic against the U-boats was effectively won in 1943, paving the way for D-Day in 1944 and eventual Allied victory.”

Phil Shanahan, author of The Real Enigma Heroes, which tells the story behind the U-559 incident, said, “I think it’s fantastic that Bletchley Park not just recognises the codebreakers, but also the men who paid the ultimate sacrifice to provide them with the information they needed to break Shark. For decades after the war the need for secrecy denied Tony Fasson, Colin Grazier and Tommy Brown the recognition they deserved but now they are celebrated in style at a world class heritage site which attracts hundreds of thousands of visitors each year. This is a very special landmark in this story."