The home of World War II codebreaking has called for engineers to operate an electro-mechanical machine developed by mathematician Alan Turing.
The Turing Bombe was a brute-force code-breaker which built on previous work conducted by Polish crypto-analysts. Bletchley Park has rebuilt one Turing Bombe, and now the museum is to launch a recruitment campaign for volunteers to operate it.
The volunteer recruitment open days at the museum, which will be on Friday 12 and Saturday 13 March, are designed to recruit operators for the project, as well as museum guides.
"We've got a number of opportunities for people interested in the history of technology," director of museum operations Kelsey Griffin told ZDNet UK on Friday. "We're looking for electrical and mechanical engineers to help operate the Turing Bombe rebuild."
Griffin said that the museum is understaffed for volunteers, a situation which has been exacerbated by growing visitor numbers.
"Visitor numbers in 2009 exceeded 100,000 visitors for the first time – while we had budgeted for the [economic] downturn," said Griffin. "It's fantastic, but it puts a strain on an already understaffed volunteer team."
The Turing Bombe was an electro-mechanical device that mechanised the process of breaking into crypto streams which had been formed by German Enigma machines, used for military communications. The Bombe was designed by Alan Turing and another mathematician, Gordon Welchman.
The machine was wired to conform to a 'menu' devised by mathematicians, based on 'cribs' or guesses of short parts of Enigma messages which could have contained commonly used words. The Turing Bombe found potential Enigma settings not by proving them, but by disproving every incorrect setting in turn.
The Bombes were built by the British Tabulating Machine company, based in Letchworth. By the end of the war, Bletchley Park and its outstations boasted 210 machines, which were subsequently broken up and destroyed to maintain secrecy at the start of the Cold War.
"[Winston] Churchill was adamant that he didn't want anyone to know how successful our codebreaking had been," said Griffin.
The museum's existing Bombe was rebuilt from a series of black and white photos and the original blueprints. The machine took fourteen years to rebuild by a dedicated team of engineers.