Bletchley Park Tour

Hut 11 - home to the Turing 'Bombes'

The Germans changed most of the Enigma keys every day at midnight, some more frequently. With the odds stacked so highly against the codebreakers, keeping pace by manual methods was well-nigh impossible. And to be of use, intelligence must be timely. To speed up the codebreaking process, a team led by Alan Turing developed an idea originally proposed by Polish cryptanalysts. The result was the Bombe - an electro-mechanical machine of clattering code wheels that greatly reduced the odds, and thereby the time required, to break the ever-changing keys.

Each machine had to be set up very accurately to achieve the best results. This job fell to the Wrens.

As the Park's workload increased, additional Bombe units were sited at many locations throughout North Buckinghamshire, as well as Stanmore and Eastcote. By 1944, there were at least two hundred machines in use.

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