Speaker meeting at Ashmores

6th January 2022 Bletchley Park –ULTRA (the ultimate secret) – Bruce Frame

Despite the fact that he confessed to playing golf with a few of our members, Bruce was obviously an experienced presenter and very knowledgeable on this subject. He said that he expected most of us present know the story of Alan Turing and Gordon Welshman and their tremendous work, with many others in breaking the Enigma code, either through the film or book. So he thought it better to talk about the machine itself.

The Enigma machine was developed in the 1920’s as a financial device…but it was a failure; however, the German military took it on to develop it to encode all their messages.

The original machine had 3 rotors, a keyboard and a lamp board, providing 26x26x26 settings or 17576, not a large number in the scheme of things. So they made the rotors interchangeable and then added two more, increasing the number of settings to over 1 million, but by adding a ‘plug board’ it was increased to 158 million million million! Enigma was reciprocal; no letter could appear as itself; the keyboard had no numbers (they had to be spelt out), but of course ‘operator error is always a possibility! However, the Germans believed that Enigma was unbreakable, despite the fact that some Polish engineers had worked it out before the war and sent their results to the English & French intelligence.

Alan Turing’s logic suggested that a machine could be developed to de-code Enigma & he built one, naming it the ‘Bombe’.  The 1^st one he built cost £100k, but a further 150 were built.  These machines could break the daily code within 30 minutes and Bruce talked about how the users identified themselves: fiancée’s name; swear word; numbers; common phrases. He mentioned the sinking of The Bismarck & how names were given to the different military organisations e.g. U-boat codes were “Shark”.  Although the Germans had worked out our British Naval codes for “convoys”, he outlined that the life expectancy on U Boats was about 2 weeks!

He then moved on to the Lorenz Tele printers, a binary system with 12 rotors giving them 16 billion billion settings!  The Heath Robinson machine, which used valves, was unreliable, and they needed the expertise of a Post Office chap called Tommy Flowers, who helped them develop ‘The Colossus’ machine, which could operate at 5000 characters/second due to its optical operation.  About 50 ‘Bombes’ and 2 ‘Colossus’ machines went to GCHQ after the war.

The 10 000 staff that were involved at Bletchley Park contributed to reducing the war by about 2 years!

An interesting suggestion he threw in at his conclusion that an apple with a bite out of it was on a bedside cabinet when Turing committed suicide, which has a remarkable possible link to the Apple Corporation’s logo?

Adrian gave Bruce a glowing Vote of thanks at which he acknowledged that all our members had been captivated by Bruce’s fascinating presentation, to which we all showed our appreciation                           AR