Secret Life of Bletchley Park - McKay Sinclair [94]
Only in the weeks after the visit did this cordial relationship start to grow bumpy and sour. For there were some on the American side who considered that the British had not reciprocated the invaluable gift of the Purple machine. No matter that Bletchley Park had sent the Americans detailed documents about Enigma and the cracking thereof, and even parts of Alan Turing’s notes on the same; what the Americans wanted was a bombe machine. And British Intelligence, as well as Alistair Denniston, was determined that the US should not have one.
On the face of it, this seems a puzzling denial; why shouldn’t an ally have full access to any technology that could help in the wider conflict? Was it simply – as American cryptographers suspected – a jealous possessiveness on the part of Bletchley Park? Was it a symptom of Bletchley Park’s neurotic insistence on maintaining control?
Or could there have been fear on the British side? Some have suggested that Bletchley Park was deeply reluctant to let the Americans anywhere near the bombes because thus far, American security had been relatively lax. If the Americans latched on to the British technology, the reasoning went, there was always the grim possibility than an enemy agent in the USA would find it very easy to fathom what they were doing, and pass the information back to Germany.
There was also the fact that in 1940, there were just six bombes in operation, and these were working at full stretch. Bletchley Park could not afford to lose even one of these machines. MI6 told Bletchley that they should not cite this reason, however, in case the Americans suggested that the bombe blueprint should be sent instead so that they could build their own.
The American reaction was – perhaps not unreasonably – an angry one. Crucially, though, this diplomatic frostiness did not affect the personal relationships between the senior cryptographers themselves. Alistair Denniston struck up a warm and enduringly useful friendship with senior American cryptographer William Friedman; in turn, it has been written, Friedman greatly admired and respected Denniston.
Though Bletchley refused to give up its bombes, it tried to help the Americans in various other ways. In November 1942, for instance, it sent the United States Alan Turing in person. He crossed the Atlantic on the Queen Elizabeth at a time when all such shipping was intensely vulnerable to the all-pervasive menace of the U-boats. Turing had been in America before, in the 1930s, and had friends there; this visit was with the purpose of creating new ones. In essence, Bletchley was lending out his intellectual expertise to their formidably wealthy ally, in the hope that his genius combined with their technological knowhow and unlimited resources would create further breakthroughs.
Having arrived at Communications Supplementary Activities (Washington), known as CSAW, Turing moved from department to department of the American cryptography operation, with an understanding that he was there by permission not of the army or navy, but of the White House itself. He was allowed complete access to all the new systems that the US cryptographers were working on, and his skills began to pay dividends. The positions of the Atlantic U-boats were at last trackable once more.
He next set to work in Bell Laboratories in New York where a top secret new idea was being developed. It was concerned with speech encipherment and call scrambling, using devices such as the Vocoder, which was being developed in Dollis Hill back in London. Known within this community as England’s top cryptographer, he based himself in Greenwich Village for work on this and other military security systems which involved twelve-hour days.
Still there was an ungovernable streak though. His biographer Andrew Hodges writes that colleagues there:
complained of Alan giving no sign of recognition or greeting when he passed