Exclusive Interview with Bletchley Park Codebreaker Hazel Gregory 🕵️‍♀️

Bletchley Park

I was posted there after serving at Uxbridge as a plotter.

They interviewed me, and asked me to do the Daily telegraph crossword puzzle. If you could do that, and do it quickly, you were in. I was interviewed by Gordon Welchman, who was subsequently my boss in ‘Hut Six’. He thought I would do, so I went there and was there for 2 years.

It was here they built the first computer, Colossus. It was constructed with Big Glass valves. It was before they had printer circuits and transistors. It’s another story, just like Keith Park. The man who worked with Alan Turing, and made the whole thing possible was a man called Tommy Flowers. He was a Post Office engineer and he was the man who got it all to work. And yet, nobody’s ever heard of him.


Code breaking

There was very little training. We had a fortnight’s training at a place in Oxford, but that was all. Then you just learned by working with someone who was experienced. The system known to the trade-unions as ‘Sitting by Nelly’.

You could do whatever you wanted. If it was successful, everybody was pleased. If it wasn’t, well you’d tried, never mind. You were not very much supervised. You just did what you could really.

I helped in bits of projects where codes were broken. Before the Colossus was invented, Alan Turing had a system called the Bombe[vii] which mechanically broke down a lot of the numbers, which would then come through to us. We had big sheets with perforations that we moved along to see if we could find the right numbers, the right words.

Nobody in Hut Six spoke really good German. We knew enough German to recognise it when we saw it though. Then it went through to Hut 3 to be translated and evaluated. Then it was sent either to the war cabinet office, or up to the Air Ministry. We were working on Luftwaffe codes in that hut. Hut 8 did the naval codes. We did the Luftwaffe.

I don’t recall how many huts there were when I joined, but Bletchley park expanded tremendously. By the time the war ended, there were 1200 people working there. Nobody lived in. Everybody was billeted locally. It amazes me now that I think of it how secretive everything was. The security was fantastic. Nobody ever, ever spoke. I was told that never, ever must I tell anyone what I had done there. When it all suddenly became public, a few years ago I had never been so surprised in my life. I wished I could have told my parents. Because they never knew (Hazel’s mother lived until 1979 and passed away never having known her daughter had been a code breaker at Bletchley Park).

You never told anybody what you were doing. It was not terribly long ago that the news broke. I was so, so surprised, because they had told us that never ever must we say what we had done, or anything about it. We never did. It must have been when the Enigma film was made. It all happened at once really. First of all I heard something on the radio. I though “good heavens! Surely they’re not telling all this!”. Then it became well known. There were lots of programs and books and things.