Caterham & District

Visit to Bletchley Park - Oct 2013

It was the day of the long predicted “St Jude storm”: rail lines were closed across the whole of southern England, thousands of homes were without power and cross channel ferries stayed in harbour. But 40 intrepid U3A members were brave enough to assemble in Caterham for the long journey to Milton Keynes to visit the famous war time code breaking centre of Bletchley Park. As a bonus we were rewarded with a high quality coach (only 2 years old) with effective, if somewhat noisy, air conditioning. In the event the roads were unusually quiet, so the journey was faster than expected with little rain and we were met with bright skies on arrival.

The visit started with a short introductory talk, given while walking across the site that lay just outside the small town of Bletchley itself. Among other things, we heard that Bletchley Park was used by Post Office Telecommunications (now BT) as a training school until the 1990's, was saved from housing development and then turned into a heritage site for the nation by the Bletchley Park Trust. For most of us this was followed by a welcome visit to the café for coffee or tea. Then we had another highly informative, hour long talk, given by a trust volunteer at various points around the large site, highlighting the functions of the Government Code and Cypher School (GC&CS).

We were also given a brief insight into the lives of the 8,000-10,000 people who worked at the Bletchley Park site. They comprised a combination of academics from Oxbridge, largely mathematicians and linguists, with thousands of support staff, mainly women enrolled as Wrens. Apparently GC&CS originally employed small numbers of “upper class” ladies who, it was felt at the time, could be trusted to keep secret the highly classified work. However, as the work expanded, so more and more “ordinary” women arrived, doing everything from typing up transcripts to running the various decoding machines. There was an all pervasive focus on security that kept all the work secret both during and after the war, which continued for over 50 years after the war had ended. Secrecy even existed between a couple who had worked separately at Bletchley Park, married after the war, but were unaware of each other's involvement until they each received their invitation to an anniversary reunion at the site.

We saw the memorial to the three Polish mathematicians who first cracked the early Enigma codes in the 1930's and built the first simple Bomba machines. Later versions of these machines known as Bombes, developed by Alan Turing, routinely broke the encoding of thousands of Enigma messages during the war. While we enjoyed lunch in the café (the home-made soup with roll is recommended), others visited the music room in the mansion itself to eat their packed lunches. Left to our own devices in the afternoon to choose where to go and what to see, we started with the Bombe room where we experienced a little of the working life of Wrens who operated these machines on a 24 hour shift system. Next came my highlight of the day, entering the National Museum of Computing to see the majestic re-constructed Colossus computer. Luckily we just caught the start of a guided tour and talk, including explanations of the Lorenz cipher machines used by the German High Command to send encoded telex type messages and the early Heath Robinson electro-mechanical machine designed to crack these hugely complex codes. We also saw the Tunny machine that produced clear text after the key to the Lorenz code had been found, thereby producing one stream of the so-called “Ultra” source material. Like other visitors when we came to the final room of H block, we were awestruck by the sight of the rebuilt Colossus II computer itself, equipped with over 2,500 valves. Classified top secret until the 1970's, today Colossus is finally recognised as the world's first electronic digital computer that was at all programmable.

We finally crossed the site to Block B which housed the main Bletchley Park museum with its many exhibits of Lorenz and Enigma machines and detailed information boards explaining how they worked. As well as WWII displays of life in the services and on the home front, we read details of life at Bletchley Park, including the social life, entertainment, music, theatre, sports, and life in the “digs” where the workers were housed. It was clear that the base was not run as a military establishment in terms of discipline, but with an ethos that was designed to encourage team work and free thinking. Downstairs we learnt about Japanese cipher codes, deception campaigns such as “Operation Mincemeat”, and the operation of “Y Stations” situated all round the south of England that picked up the encoded transmissions from the Axis powers in Europe. We also read outlines of lives of key mathematicians who worked on site, including Alan Turing “the father of modern computing” who was commemorated in a most impressive life size slate statue. Finally we saw the demonstration of a working re-construction of a Bombe, the machine that regularly cracked the Enigma codes that changed every day.

Unlike others, we didn't find time to visit the Toy museum, the Naval hut, the Churchill exhibition, the Pidgeon Loft, the Post Office or the Vintage cars. As some buildings undergoing major restoration were closed, it was suggested a return visit might be in order at some point in the future. We enjoyed a good return journey home, despite queuing at major M25 junctions: a smooth enough ride to prepare a first draft of this report via smart-phone on the coach!

Richard Andrews