Friday, April 02, 2010

Subject: Re: Large Machine

Part of the Enigma decoding system. Just after you posted this there was a whole story about it on the History channel.

Goody

Hi Goody,

It was called the "Bombe" and was developed here in the U.S. after the Bletchley gang, in England, gave up trying to decode the enigma stuff. It was only recently that our government acknowledged that it existed, and gave credit to the designers and all the women that did the soldering and "grunt" work.
supposedly, Alan Turing came over to inspect it and said that it would never work!

Here is an except from Wikipedia:

US Navy Bombe

US Navy bombe. It contained 16 four-rota Enigma-equivalents and was much faster than the British bombe.Funding for a full, $2 million, navy development effort was requested on 3 September 1942 and approved the following day. Commander Edward Travis, Deputy Director and Frank Birch, Head of the German Naval Section travelled from Bletchley Park to Washington in September 1942 to establish a relationship of "full collaboration" with OP-20-G.[25] An all electronic solution to the problem of a fast bombe was considered, but rejected for pragmatic reasons, and a contract was let with the National Cash Register Corporation (NCR) in Dayton, Ohio. This established the United States Naval Computing Machine Laboratory. Engineering development was led by NCR's Joseph Desch.

Alan Turing, who had written a memorandum to OP-20-G probably in 1941,[27] visited OP-20-G in December 1942, and went to NCR in Dayton on the 21st. He was able to show that it was not necessary to build 336 Bombes, one for each wheel order, by utilising techniques such as Banburismus. The initial order was scaled down to 96 machines.

The US Navy bombes used drums for the Enigma rotors in much the same way as the British bombes. They had eight Enigma-equivalents on the front and eight on the back of the machines. The fast drum, however, rotated at 1,725 rpm, 34 times the speed of the early British bombes. When a 'stop' was found, the machine over-ran as it slowed, reversed to the position found and printed it out before re-starting. The first Navy bombes became available in late May 1943. They were 10 feet (3.0 m) wide, 7 feet (2.1 m) high, 2 feet (0.61 m) deep and weighed 2½ tons.

Production was stopped in September 1944 after 121 had been made. The last-manufactured US Navy bombe is on display at the US National Cryptologic Museum. Jack Ingram, Curator of the museum, describes being told of the existence of a second bombe and searching for it but not finding it whole. Whether it remains in storage in pieces, waiting to be discovered, or no longer exists, is unknown.


Dave