“Information gained from the Colossus machine shortened the war by two years”
Iwas sent to work at Bletchley Park in 1943 and had to sign the Official Secrets Act. They wouldn’t say what I’d be doing until I’d signed it. Then I was told, ‘You’ll be deciphering German messages’; I had two weeks to learn the Baudot code.
“I’d joined the Wrens because I wanted excitement so ending up in a top-secret role in codebreaking was per fect! But I had to keep my excitement to myself. I couldn’t tell anyone!
“The boffins at Bletchley Park created a replica of a Lorenz machine, designed by the Germans to send coded messages that were more secure and unbreakable than Enigma. It was used by senior Nazis operating at the highest levels, so the messages were obviously of huge interest to the British and provided information about German military plans.
“I was doing mathematical work to identify significant numbers; a cryptographer deciphered the code from there. We were never told what the messages were, but occasionally we were told about a special breakthrough. This helped us feel valued.
“The Colossus machine, arguably the world’s first computer, was built in 1943 to crack a Nazi code. They called it a ‘Heath Robinson’ because it was created in a rush with spare parts.
“The messages we broke with Colossus showed that Hitler had swallowed a deception plan for D-Day. Information gained from Colossus shortened the war by two years.
“We played table tennis in the mansion at lunchtime. There were clubs, drama societies and music. I was billeted at Woburn Abbey, and on a few occasions we sunbathed nude on the roof. We were hauled before the First Officer who said we were not allowed to do this; apparently we were distracting the pilots!” Nancy Hookham, codebreaker