Form 6 become code breakers for a day during their trip to Bletchley Park
It is World War 2, 1941, and Britain’s Naval forces are being severely tested by the constant pressure of the German U-Boat attacks in the Atlantic. And it seems that there is only one way to stop them. By cracking Enigma. Based deep in English countryside is a top secret station for the greatest minds in Britain, Bletchley Park. Their sole purpose is to break the codes and steer allied vessels away from the waiting German submarines so that supplies arrive safely from overseas. But how will they do it? Form 6x travelled there to find out.
Our investigations began at a workshop at the heart of the museum where we learnt what life was like at Bletchley Park for those who worked there. We also learnt how secretive the operatives had to be about what they were doing; many couldn’t even talk to their own colleagues in other huts. We uncovered some important clues about the Enigma machine by inspecting a replica of the real model which revealed how many different ways there were to encode a message. There were five different wheels, each having around 26 prongs, meaning that there were just under 159 quintillion permutations. The operator would select three of these wheels to slot into the machine, and each different setting made an alternative base code. Cracking these codes would be tough.
We were training to be new recruits at Bletchley and were to be briefed about decoding messages sent in Morse code from the Germans. This would help us to plot cardboard ships on a large map of the wartime area. We were staggered at the blistering pace at which Morse code messages came in (those decoders would have to have a sharp ear) and were given our own code sheet and assigned a challenge to decode a short message. It took a good deal of concentration but we managed to crack it.
Following our success, we were taken to the room which housed a large working replica of a bombe machine, the prototype computer painstakingly developed by Alan Turing and his team to efficiently decrypt the German Enigma codes for any given day. In two hours, each machine could rifle through at least 17,000 permutations, using 36 sets of wheels. However, the codes were reset by the Germans every 24 hours- more than a minor issue that would confound Turing and his colleagues.
The operator might guess at a certain word of the code and would slot this information into the machine to verify if his theory was sound. It would do this by checking a letter at a time and then stop if the letter was correct. It would then restart and repeat the process. If the bombe stopped completely then the operator knew that his guess was wide of the mark.
The museum sector in that same room allowed us to, as part of our training, discover about Alan Turing’s secretive life and the inner workings of the Enigma. We learnt that the Navy codes had eight wheels, meaning that there were even more possibilities. Another interesting fact was that the cracking of Enigma was only made possible by the recruits of the Navy looting a German submarine and retrieving a codebook of the codes for the next couple of months. As we left, I noticed an old bombe which I believe was one of the original devices used at Bletchley by the great Turing himself.
The radio station we visited was Britain’s main radio headquarters. We all got an idea of how it worked by having a go at sending a Morse Code message and it was interesting to see the leader directing a conversation in Morse with a correspondent based in Australia. Whilst he was talking with this correspondent, the board above displayed a red dot indicating where the message was being received from.
Then finally there was the tour. Our guide was a local villager who lived down the road from Bletchley Park during the war, and he told us how the Germans, after fleeing, dropped their remaining bombs into the fields behind his house, creating five large equally spaced potholes. Due to his presence in wartime, the man was very knowledgeable.
One of the huts that he led us to housed a motorbike that would transport loot from enemy submarines, or important plans. The guide was eager to point out that we owe a great deal of thanks to these bikers, and that we have never really repaid their sacrifices. We also visited the office block of Alan Turing, where the groups learnt about the role of pigeons in the war and had a peek at his cramped office quarters.
After a day packed full of top secret training, many recruits returned with a certificate for excellence in Morse code. Who knows? Perhaps these Form 6 pupils might now be inspired to become the code breakers of the future.