Yesterday the Aberdeen branch of the BCS (online) hosted two lectures by Dr. Mark Baldwin about the Enigma machine titled “The Codebreakers: Enigma, Bletchley Park & the Battle of the Atlantic”. The first talk of the day was held at the Satrosphere Science Centre to an audience of about 25 persons mainly members of the BCS. The second public talk was held at the Sir Ian Wood Building, Robert Gordon University to an audience of some 65 persons. The talk began around 18:30 and concluded around 20:20 with the opportunity for questions and a viewing of some World War 2 Enigma machines and also a modern day simulation that one could build for around £120stg.
It was really quite fascinating to hear to story of its evolution beginning around the time of World War 1 and of its evolution over a twenty year period. In parallel was the story of what began in the early 1930’s on “breaking” the Enigma ciphers.
A very interesting graph was displayed during the a discussion on the Battle of the Atlantic showing the monthly merchant shipping losses in thousands of tonnes. One could see some key points in time that coincided with the acquisition of hardware / code books and the reduction in shipping losses shortly thereafter. In addition one could also see the increase in losses when the Enigma machine went from three rotors to four.
It was really interesting to learn about the inner workings of the machine focusing in on the wiring configuration and mechanical operations that allowed for a different encoded letter be generated every time you pressed the same input key. The mechanism by how it works is surprisingly simple, essentially just creating a simple loop through which current can flow – thereby illuminating a small bulb. It was really amazing to see that for all of its simplicity it could generate a huge number of possible outcomes – each rotor generating 26 factorial combinations which in turn was magnified by a front panel allowing one to wire up one particular letter with another.
It was also really great to see up close the actual Enigma machine that appeared roughly 10 minutes into the film “The Imitation Game” (imdb), (trailer). The following links may give you some further information about Enigma should you wish to know more: (online), (online), (online).
The images below may be found in the following flickr photo album (online).
Dr. Daniel C. Doolan News & Photos 
A terrible time in our history was brouvht to conclusion as a result of our gettinhl on hands on this machine. Great series and priority information.