- Contributed by
- Dundee Central Library
- People in story:
- Kennedy McConnell
- Location of story:
- Eastcote, Middlesex
- Background to story:
- Royal Air Force
- Article ID:
- Contributed on:
- 10 November 2005
Ken McConnell, veteran of Enigma, in 2005
(Kennedy McConnell was an R.A.F. electrical engineer working on the Turing designed "Bombe" decoding machines. In 2003 he produced a professionally filmed lecture series, which has been copied on to videotape and DVD. The full series, comprising approximately seven hours of detailed historical analysis, can be viewed at Dundee Central Library. There are additional copies of the film at the Bletchley Park Trust, the Scottish National Museum, the Imperial War Museum and the National War Museums of America, Australia, and Canada).
When Britain declared war on Germany in September 1939, I was studying electrical engineering, which was a Reserved Occupation. However, after the Dunkirk evacuation in June 1940, when a German invasion was imminent, I volunteered for the RAF. I was trained as an electrical technician, and posted to 143 Squadron, Coastal Command. For the next two years, I worked on Blenheims and Beaufighters and served on various UK stations. I was then selected to join a technical team which was being assembled for some top secret project. After passing a rigorous entrance exam, and signing the Official Secrets Act, I found that this team would be helping cryptographers to attack the German ENIGMA codes.
Throughout the Second World War, all German air, land and sea forces used Enigma machines to encipher their radio signals. At least 50,000 were in service by 1945. Because of its complex mechanism and variable circuitry, this portable electro-mechanical machine was able to change plain text into scrambled output and provide over 150 million permutations. Consequently, Hitler and his intelligence advisers were convinced that their radio traffic would be completely secure. This proved to be a disastrous assumption, because the combined skills of cryptographers and engineers enabled us to break the Enigma codes on a daily basis from 1940 to 1945. The resultant intelligence was code named ULTRA.
The secret of this historic success was an amazing machine invented by Alan Turing, who was a famous mathematician. His brainchild was the forerunner of the modern computer. Thousands of Enigma signals were intercepted daily at receiving stations located throughout Britain. All these intercepts were relayed by teleprinter to the code breaking headquarters at Bletchley Park. From this hour-by-hour supply of raw material, our cryptographers applied their mathematical expertise to deduce programmes for the Turing machines.
All possible Enigma permutations were then tested at a rate of 1,000 per minute. This procedure continued until the correct settings were identified. This search could last from a few hours for the Luftwaffe, up to several days for the U-Boats. The cryptographers were then able to decipher all messages transmitted from that radio network. By 1943, these local networks were spread across Europe, Russia and North Africa. Consequently, we had to contend with many different codes. The settings on all Enigma machines were changed at one minute after midnight, so the same sequence of testing had to be repeated daily. The machines were operated 24 hours per day and 7 days per week by teams of WRENS. Two per machine were required on each shift, so about 1,700 were involved.
From 1940 to 1945, these unique machines were continually being improved in the light of operational experience. Later models were nick-named ‘Jumbos’. My role was to help with their development and maintenance. A total of 250 RAF Sergeants
were involved in this demanding duty. We had to work shifts like the Wrens. Minor faults were prevalent and had to be rectified urgently.
After VE Day in May 1945, Churchill ordered that all the Turing machines had to be dismantled. I was involved in this depressing task, before being demobbed in 1946.
For more than 30 years, we were forbidden to reveal that the Enigma codes had been broken. In 1978, the Government issued rather confusing guidelines on disclosure. We could tell what we had done, but not how we did it. Although my contribution was minor, I am proud to have been involved in this historic achievement, which influenced Allied strategy, saved thousands of lives, and helped to win the war.
Kennedy McConnell via Dundee Central Library
see also "An Amazing Wartime Secret" by the same author.
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