Friday 24 September 2010

Bletchley Park: Alan Turing & Enigma

The mansion at Bletchley Park

Bletchley Park, near Milton Keynes in Buckinghamshire, was Station X, the home of the Government Code and Cipher School set up by Winston Churchill during World War II. It is now a museum and a tribute to the vital work that went on here which is reckoned to have shortened the war by two years and to have saved thousands of lives. Churchill quickly realised the importance to the war effort of code-and cipher-breaking, and his famous "Action This Day" order ensured that the operation was set up with all speed. Later, he paid tribute to the loyalty and integrity of the Bletchley workers by calling them "the geese that laid the golden egg but never cackled".

Top mathematicians such as Alan Turing and Gordon Welchman were recruited to find ways of breaking the complex and ever-changing ciphers generated by German Enigma and Lorenz machines which were used to transmit messages between German High Command and their armed forces. Turing and Welchman, building on work done prewar by Polish crypto-analysts, were instrumental in inventing the Bombe which decrypted Enigma messages thousands of times faster than the human brain, whilst Colossus, the world’s first practical electronic digital information processing machine - a forerunner of today’s computers, was developed to deal with messages from the more complex Lorenz machines. Station X: The Codebreakers of Bletchley Park by Michael Smith is a good overview of what happened here.

Today, thanks to the splendid efforts of enthusiasts and computer experts, there are at Bletchley Park functioning rebuilds of both the Bombe and Colossus. See here (for more on the Bombe rebuild) and here (for Colossus).

Whilst the top boffins at Bletchley Park were all men (this was the 1940s after all), the actual work with the machines was mainly done by women who were recruited for their intelligence and quickness of mind. Gordon Welchman paid tribute to two of his assistants, Miss Rock and Miss Lever, by paraphrasing Archimedes thusly: "Give me a Lever and a Rock and I will move the universe."

Alan Turing's office in Hut 8

Block B contains the main exhibition including several Enigma machines and the Bombe rebuild, as well as a very striking statue of Alan Turing made of slivers of slate.

Alan Turing Statue in main exhibition Block B

No photo can do justice to this magnificent tribute to Alan Turing by sculptor Stephen Kettle. Kettle has shown a seated Turing studying an Enigma machine. The detail is breathtaking - the shoelaces, for example, are composed of 200 individual pieces of slate! It's worth visiting Stephen Kettle's website where he shows close-up photos of the statue and writes about the thoughtfulness and detail that went into its making.

Alan Turing, the father of computer science,

was perhaps the most interesting and the most tragic of the many geniuses who presided at Bletchley Park during World War II. The most brilliant mathematician of his generation, he should have been regarded as a war hero for his vital work at Bletchley but his life ended in undeserved disgrace and death in 1954 at the age of only 41. Whilst working on computers at Manchester University, he was convicted of a homosexual act (this being illegal at the time) and he chose chemical castration over a prison sentence. But the side effects of this and the concomitant destruction of his ongoing work for Bletchley Park's successor GCHQ, led him to take his own life by means of an apple laced with potassium cyanide. There's surely some symbolism here to do with knowledge and lost innocence, and I wonder if Turing chose an apple with any of this in mind.

Andrew Hodges' Alan Turing: The Enigma is probably the definitive biography and the author has generously supplemented it with a comprehensive website devoted to Alan Turing.

2012 sees the centenary of his birth and this website outlines a programme of commemorative events.

There's so much else to see and do at Bletchley Park (do see the website for details), you really can't do it all in a day, so tickets (valid for as many visits as you like in a year) are wonderful value.

Please support this stirring part of our heritage - visit soon and often! Bletchley Park receives no funds from government and relies on Heritage Lottery grants and the generosity of the general public to carry on its task of restoring and preserving the many historic buildings on the site (from wooden huts to a mansion). On our recent visit it was good to see the restoration of Hut 8 (where Alan Turing worked on Naval Enigma) with a reconstruction of Turing's office and other rooms dedicated to the sailors from HMS Petard who gave their lives retrieving vital Enigma code books from a sunken German U-Boat, and to the valuable war service of homing pigeons which is a lot more interesting than it sounds - there really were Hero Pigeons of World War II!