Secret Life of Bletchley Park - McKay Sinclair [36]
In addition to their factual content, these decodes produced an important psychological boost. In the days of the Phoney War, tension was high. No one had yet managed to stop the German army. All knew that Nazi territorial ambitions were virtually limitless. Along with the desperate scramble to rearm and train her forces, Britain was in a furious struggle to gain an advantage in intelligence. That first break into the army code of the previously unbreakable Enigma machine was a source of some relief.
Perhaps the weight of the unrelenting pressure was behind an explosive row between Dilly Knox and Alistair Denniston. For reasons of security, Denniston had been extremely reluctant to let Alan Turing travel to Paris with the Zygalski sheets; Knox, on the other hand, felt that aid and assistance to the Polish and French cryptographers was a promise that the Park was honour-bound to keep. The argument came to a head when Knox wrote Denniston this sulphurous letter, opening ‘My dear Alistair’:
[The statistics] must be handed over at once … My personal feelings on the subject are so strong that unless they leave by Wednesday night, I shall tender my resignation.
I do not want to go to Paris but if you cannot secure another messenger, I am actually at the moment completely idle.9
Of course, Turing went, and Denniston bowed to Knox. But there were to be further outbreaks of ill-temper and seething resentment between the two old friends.
And the pressure to achieve results was only to grow. It was Gordon Welchman who, even at the earliest stages, saw that Bletchley would have to be moved into what might be termed ‘mass production’ – especially when the first regular, daily breaks into Enigma were made, for then they would have access to thousands of intercepted messages daily – and that numbers at Bletchley Park had to increase dramatically. And it was Welchman, rather than the veteran Knox, who made representations to Alistair Denniston and his deputy Edward Travis. Welchman was also helping Alan Turing with the development of the bombes. He was clearly a young man with a colossal amount of energy and enthusiasm.
The early months of the war had given the operatives at Bletchley a terrific head start. For although the fighting on land had yet to begin, hostilities at sea were under way, allowing the codebreakers a period of time in which to hone their skills on German traffic. ‘The exercise gave us invaluable practice,’ says one cryptologist. ‘And it provided us with a battery of cribs of which we were able to make use when the war became real.’
Bletchley Park, and by extension the entire military machine, was relying upon human inspiration. The circumstances in which it came were quite extraordinary.
9 1940: Inspiration – and Intensity
On a week of damp, chilly nights in February 1940, at a point when the Germans had further changed the settings of their military Enigma machines – and in the days before the arrival of Turing’s bombes – the young John Herivel was in the sitting room of his billet, in his customary position before the fire, ‘always concentrating on the encoded messages,’ as he wrote, ‘and always totally without any glimmer of progress.
Then suddenly one night something very strange happened; I may have dozed off before the fire – a dangerous thing to do as I often smoked a pipe and might have burnt a hole in my landlady’s carpet, or worse – and perhaps I woke up with a start and the faint trace of a vanishing dream in my head. Whatever it was, I was left with a distinct picture – imagined of course – in my mind’s eye, of a German Enigma operator.
This was the trigger that was to set off my discoveries … I seem to have taken Aristotle’s advice, that you cannot really understand anything thoroughly unless you see it growing from the beginning.
In this case, the beginning would be early in the morning when the wretched operator would have to wake or be wakened and set up the new key of the day on his machine.1
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