Bletchley Park,

site of the British codebreaking activities and birthplace of the modern computer

Bletchley Park is located in Milton Keynes and is within easy walking distance from the train station.  These photographs were made on 22 April 2007.

Click on a thumbnail image to download the full-size photograph.


The Mansion, what happens when people have too much wealth.  This monstrosity was built Sir Herbert Samuel and Lady Fanny Leon.  Not surprisingly, the developer who acquired the estate after their deaths intended to demolish it.  The British government, however, stepped in, acquiring the Mansion and estate for their war time codebreaking activities.  Much has been written about the codebreaking activities of Bletchley Park.  The official web site is:            
The building where Alan Turing, Gordon Welchman, and other cryptographers worked.  
Hut #5, one of the original codebreaking huts.  Each of several huts was devoted to cracking a specific cipher.  Hut 5 is now a wireless station and is open to the public.  Most of the remaining huts are in dilapidated condition and are not open to the public. 

Three of the famous National HRO radio receivers of the type used to intercept German wartime Morse code communications.  These radios offered superb selectivity and are ideally suited for the reception of Morse code.  A testament to the high quality of the National HRO is that the receiver was in commercial production for 30 years!

Several views of a bombe, an ingenious device used to decipher German messages encoded with the Enigma device.  Devised by Turing and Welchman, and built on fundamental discoveries of Polish crypto-analysts, the bombe mechanically explored all possible combinations of encoded messages.  The Enigma cipher had one fatal flaw: no letter could be encoded as itself.  Deciphering required merely a bombe, time, and genius.         
Here is the text from the plaque in front of the display:

"This is the Rebuild of a 1944 Colossus Mk 2 Computer.

It is being used to find the 12 wheel settings on a German Lorenz cipher machine which was used to encipher an intercepted German teleprinter message.

The intercepted message has been punched onto paper tape in the teleprinter code and loaded as an endless loop onto the 'bedstead' on the right hand side of Colossus. Here it is being read optically at 5,000 characters per second as data going into Colossus.

Colossus is then using its 2,500 valves (tubes to the Americans!) and switched programs to try various possible wheel starts, looking for the maximum score that appears on the lamp panel on the left hand side of Colossus.

When the highest score has been found it is printed on the typewriter together with the wheel setting it has found.

When all 12 wheel positions have been found another machine called Tunny is then used to decipher the message.

It took about 8 hours to find all 12 wheel settings."


World War II German encryption machines including a Lorenz SZ42 and a four-wheel Enigma (G-312 Abweher) device.       
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