imitation game movie

On 10/02/2015 05:21, Jon Elson wrote: I've not seen it but there's been a lot of criticism about historical (in)accuracy. I'm not an expert, but I think you're a bit wide of the mark in places. You're evidently referring to the US Navy bombes. Although the original contract was apparently for 350, only 121 were ever built, including prototypes, and they were used at the US Navy Communications Annex in Washington, not Ft Meade. The US Army also had a small number of bombes built closer to a British design. And the reproduction at Bletchley doesn't run at the full speed of the later British ones, although it's true the US Navy Bombe was a good deal faster (850rpm or 1725rpm vs 120rpm; various sources suggest between 5 and 10 times faster in practice). Bletchley itself had only a small number of bombes. Most of the 224 built in Britain were housed at outstations. Because I've not seen the film, I don't know what the "clunk-clunk-clunk" you refer to is, but I've seen and heard the bombe running and I would bet it's the sound of the middle wheels advancing, roughly once a second on the replica, but faster on most of the British bombes. They didn't. No bombes were ever shipped across the Atlantic. Only design drawings and information were, in the care of officers from the US Army and Navy in 1941, and later two USN and some senior Bletchley staff in 1942. The US Navy bombe was an adaptation of the British design from the latter exchange, and went into service in 1943. Britain had been using their bombes for several years by then, of course. Bletchley apparently did use USN bombes, but not directly. They did it by sending cribs and getting the stops and settings back over encrypted cable, to be used for decryption of 4-rotor Naval Enigma messages at Bletchley Park. All made by the British Tabulating Machine Company (BTM), though they subcontracted some parts. -- Pete -- Pete Pete Turnbull