OBITUARY : Gil Hayward

20 Oct 2011

OBITUARY : Gil Hayward
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Gil Hayward, who died on October 9 aged 93, contributed to the wartime 
design of the "Tunny" decryption machines at the Post Office Research 
Station at Dollis Hill, north London, and later at Bletchley Park.

Tunny was a British re-engineering of the German Lorenz SZ42 cipher 
machine used in radio teleprinter communications between members of the 
German High Command. The Lorenz was thus used to transmit even higher 
grade secrets than the more famous Enigma machine, which had only three or 
four encoding "wheels" compared to the Lorenz's 12.

The original break into Lorenz had occurred after a German cipher clerk 
enciphered two long messages using the same initial settings of the 
machine's 12 wheels, and in early 1944 the decision was made to construct 
a number of replica machines, under the direction of Tommy Flowers, at the 
Post Office Research Station at Dollis Hill.

Intercepted messages in code could be fed into these Tunny machines, but 
the problem remained of how to determine which wheel settings to employ to 
produce the messages in deciphered "clear". Painfully slow decrypting work 
was done by hand until the development of the Colossus machine, now 
recognised as the first modern computer. Its calculating power reduced the 
time spent establishing the wheel settings from several weeks to a few 
days, allowing commanders in the field to act on the resulting 
information...../snip/


....In retirement Hayward helped researchers rebuild Colossus and Tunny, 
which had been broken up after the war, by making 600 pattern plugs and 
1,000 valve holders. Luckily he had squirrelled away plans for the 
machines - against the orders of Churchill, who had feared that the 
technology might find its way into Russian hands.

His contribution to the war effort was recognised in 1996 when he was 
presented to the Duke of Kent on the opening of Bletchley Park Museum. 
Last year he was presented with a special medal from the Prime Minister, 
in recognition of his contribution to the code breaking effort.

Gil Hayward's first marriage to Irene was dissolved and he married 
secondly, in 1969, Maisie Blencowe. She survives him with a son by his 
first marriage and a stepson.

Gil Hayward, born October 16 1917, died October 9 2011 


http://www.telegraph.co.uk/news/obituaries/technology-obituaries/8837249/Gil-Hayward.html

http://i.telegraph.co.uk/multimedia/archive/02031/hayward_2031544c.jpg