Memory Project

Dorothy Mary Stirling

This testimony is part of the Memory Project Archive

HDI
HDI
Dorothy Stirling, March 2010.
HDI
The Germans anticipated that their messages were unbreakable. And they were almost, but the machines that they were using to encode, one of them was captured.
I went into working on the Enigma machines. Not in the main branch where the centre was, but they had out stations. The out station, it wasn’t known to be what it really was. It was actually, you might say, clerical type work. You assumed to be, which, of course, it wasn’t. We had quarters, our cabins, and the working block had different bays, what we called bays, you know, off the centre, either side, with the machine on them. They were taller than I was and I would say maybe six feet, I can’t recall exactly, you know what the measurements were from end to end. They had banks of drums with three drums on each bank, and the full length of the machine. You had jacks that you plugged into the back of the machine going from whatever you were told to do, this to that and that to this, wires going and plugging into the jack. We sent them up and turned the machines on and there was a sort of a, not exactly a typewriter, but it typed out when the machine stopped. You know, which had worked and, of course, as far as we know, we just sent the results back to Bletchley Park, where they would work on them, the actual decoding of the actual message. Sometimes it was easy because sometimes the Germans, figuring that everything was quite okay, they’d put maybe the locale or maybe the date, where you could work from that, going backwards I suppose. But with each letter, the combination changed, so it was quite a feat for the ones that sorted out the original, you know broke the code. The Germans anticipated that their messages were unbreakable. And they were almost, but the machines that they were using to encode, one of them was captured; and working on that and working backwards, finding out a way to break that code was a real feat, which I wasn’t involved in, of course. But we were just breaking down the codes with the information we were given and we didn’t get the full message. It was just working on parts of the message. We called them the bombs. We didn’t call them the Enigma machines. For the sake I suppose of covering everything, each bomb had a name like Calcutta or whatever. They were given names and when you filled in your sheet, you filled in the name of the machine you were on and we didn’t call them the Enigmas.