Probus Visit to Bletchley Park



32 members and guests visited Bletchley Park,  home of the Allied code breakers during WW II,  on Tuesday 22 May 2018.   The site has been recently refurbished and renovated to preserve the heritage for future generations. In the Second World War it housed the Government Code and Cypher School which regularly decoded the secret communications of the Axis powers, the most important of which were the German Enigma and Lorenz ciphers.


The naval, military and air sections were on the ground floor of the Mansion and the top floor was allocated to MI6.       Construction of the wooden huts was begun in 1939 with non-naval enigma messages being deciphered in Hut 6 and translation, indexing and cross referencing in Hut 3.








Naval Enigma messages were originally deciphered in  Hut 8 and then translated in Hut 4.      Within a short time 12 further huts were added as the work expanded and became more specialized including Hut 2 which was used for beer, teas and general relaxation.      Initially there was a wireless room in the Mansion but this was moved to nearby Whaddon Hall.


The Enigma coding machine had been developed in the late 1920s by a German engineer and its military potential was soon recognized.        Shortly before the outbreak of the war the Polish Cypher Bureau based in Warsaw broke the Enigma Code and, with the invasion of Poland imminent, the information and techniques were passed to the British.     The bombe, designed by Alan Turing was a bank of early computers designed to uncover some of the increasingly complex daily settings of the Enigma machine used by the various German military networks and the Luftwaffe.   


  At its peak the code breakers at Bletchley were reading 4,000 messages a day sent in by a chain of wireless intercept stations.   The communications of the German Navy proved more difficult to read as they had much tighter procedures after the introduction of the four rotor Enigma.    Their communications could only be deciphered after the successful launch of the US Navy bombe which continued operating for the rest of the war.  Most of the material which had been recorded and passed on to Bletchley by motorcycle or teleprinter was deciphered in Block D,  a maze of corridors and windowless room.     


The Lorenz system was used for high level messages between German High Command and field commanders.     However, operator errors crept in which helped those at Bletchley to work out the logical structures of the German machines.       Automatic machinery was constructed to help with the decryption which led to the construction of Colossus,  the world’s first digital electronic computer which could be programmed.     This was designed and built by Tommy Flowers and his team and was delivered to Bletchley where it was further developed.


After the messages had been analysed the contents were sent on to the relevant organisations or commanders in the field as intelligence reports.


After the war the secrecy imposed on the Bletchley staff remained in force although some leaks were inevitable and most of the Park over time became a conservation area.  Eventually The Bletchley Park Trust was formed to maintain the site as a museum, refurbishing the exteriors of some of the huts and to make it a tourist attraction.  It now has a large visitor centre and has a major educational component catering for  school parties.


 Some Probus members and guests enjoying the visit:











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