Tuesday, 15 March 2011

Day trip to Bletchley Park


As ever, please double-click on an image to see it full size.

The lake and house, Bletchley Park

A few weeks ago in our 'Local' (The Horse & Jockey, Wilmslow) we got to chatting about code breaking and Bletchley Park. I suggested we make a day trip there, and the idea was enthusiastically received by the group. It fell to me, as suggester, to organise it so I looked several weeks ahead in my diary and e-mailed everyone with a proposed date of Tuesday 15th March. Amazingly, all six who wanted to go could make that date, so I collected the train fares from them and made a block booking.

Our 'Old Gits' railcards got us 33% discount, but we did better than that! The card also gave us Virgin peak fares at off-peak prices, so a return ticket from Wilmslow to Bletchley leaving on the 08:11 (changing at Crewe and Milton Keynes) to get us to Bletchley just after 10:00 was £35.20 instead of the £168.00 it would have cost without the card.

Three Peters and me! L to R Peters Stanley, de la Wyche, and Helliwell.
I'm reading the map.

First, we had a coffee in the museum's cafe, then joined a tour of the site.

Our guide tells us the history of the house at Bletchley

We started by the house, with its history, before moving on to see some Enigma encryption machines, as well as some more advanced Lorenz machines.

The famous and very effective Enigma machine, used by the Germans for encrypting and decrypting messages. One of Bletchley's main tasks was deciphering messages sent by Enigma. The machine uses 'rotors' which translate the typed letter to a different letter, that letter dependant on the setting of the rotor. This Machine has four rotors, and they advance after each character to translate the typed character to yet a different one. In addition, a plug board further scrambles the characters. Operators needed to set up their machines so each rotor and the plug board matched the 'code of the day'.

Enigma rotors

Enigma plug board

The Lorenz machine, a development of Enigma

This dispatch rider's bike was used to deliver documents to and from Bletchley during World War Two. It was ridden by a local man, who at the end of the war didn't know what to do with his motorcycle - so he took it home. After he passed away some years ago his widow donated it to the museum.

Turing's 'Bombe', used to fast-decode Enigma-encoded messages

Some of the banks of relays behind the rotors in the Bombe

Lunch in Hut 4. Me, Malcolm, Ivan, and Peter de la.

Hut 4 exterior

Parked near the 'Colossus' building and the National Computer Museum is this somewhat tatty Harrier

The Bletchley park site comprises the old house, and many wooden huts built in the grounds of the house for the hundreds of staff who worked here during the war years. They were billeted in the many villages around the area and bussed in and out every day.

Some of the huts, and some later buildings on the site, are very run down.

The 'James Bond' connection. Ian Flemming worked here, and this place must have been the inspiration for his novels.

Some of the real heroes of Bletchley, not least Gordon Welchman and, perhaps the number one man in code breaking and very early computing, Alan Turing.

Hut 8, where much of Turing's code breaking took place

No computers were developed at Bletchley, only code-breaking electronic and electro-mechanical calculators. However, Turing went to Manchester University after the war to join Williams and Kilburn in developing the world's very first stored-progam computer, the 'Baby', of which a working replica is demonstrated at the Museum of Science & Industry in Manchester.

A stored program computer is a device that can vary its processing steps dependant upon the results of the current step. In other words, it can perform 'conditional jumps' in its program so what it does with the data it is fed depends on the characteristics of that data. A calculating machine, however, will always follow a fixed series of operations regardless of the data fed in.

I spent the second half of the day in the National Computer Museum on the Bletchley site. To a retired career Computing professional (me!) it was so fascinating that I completely forgot to take any photographs! I will remedy that on a future visit. I will be back!

Most pictures in this post are ©Mike Hyslop, others ©Vince Chadwick

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