Bletchley Park
GC&CS
Station X
This is a place where anyone who has been in the service of our Country, will feel quite at home.
Background
Bletchley Park has a comforting, quite, peaceful feel, but when you sit still and contemplate your surroundings, it is not difficult to remember or imagine the hectic days of the Second World War and the activities that were shrouded in secrecy that took place in and around the site.
From the air it would not be difficult to mistake the site as a Hospital complex or to give it some other simple explanation. This is where all reality ends and the truth begins.
As soon as the history of the site starts to unfold, evocative phrases like MI5, MI6, MI8, Codes and Ciphers, RSS, SCU's, begin to surface adding an air of secrecy to the activities and the people of the site. This is a topic that may take me and many others the rest of our lives to try to unfold but many of us are all working on our own sphere of interest and passing on anything that we may find to the others, much of the work is slow and boring but now and again something of great interest gets the pulse racing, and if we do not do it, who will?
I will try to put together a reasonable account of my understanding of the events and characters, but history shows that things change over time as new information comes to light, so please be forgiving in your criticisms, and remember I am only doing my best.
The Author of this Work
Over the last few years, I am proud to have become an honorary member of the Beaumanor Association, and the Radio Security Service Box 25 (The Voluntary Interceptors). I was also training as a guide at Bletchley Park until events caused me to take a break for a while, but I should get back to it sometime soon, I hope.
So if you are sitting comfortably? I shall begin.
Introduction
The full story of Bletchley Park consists of two intertwined disciplines and many others used around the edges, all of which were evolving and an integral part of the overall work at Bletchley Park. Enigma was not the only cipher machine that was worked on, and the German's were not the only country to have their radio signals intercepted. I will not go into the History of the site before WWII and suggest that a visit would not only be a good day out but may help to cement the feeling and atmosphere of Bletchley Park, the guides will give you a very interesting and informative tour, as well as being able to answer your questions and make you smile. I also do not intend to recreate the excellent work produced by others like Tony Sale.
In the Beginning
During WWI signals intelligence became a valuable asset to the commanders at the front, for the first time in a major conflict radios were becoming a useful resource. Land lines were still the main method of communicating and many novel ways of taping into the telephone lines were tried and tested, with varying degrees of success. With the front lines being so close together and with the technology of the day, rapid advances in wireless (radio) communications were being achieved. The Royal Flying Corps was emerging as the for runner for the Royal Air Force, The premier intelligence services were by later standards very small, the Navy was for the first time able to communicate whilst at sea via wireless (radio) systems, and tanks had not yet been thought of. This time, although not that far back in history was still a time of technological innocence compared with what was to come over the next 90 years.
Cipher technology had been in use for thousands of years by this time, mechanical and electromechanical cryptographic equipment was just emerging as a viable entity.
In 1908 the Royal Engineer Signal Service was formed and provided communications during World War 1. At this time the Dispatch Rider (DR) came into prominence and wireless 'sets' were introduced into service.
At the end of WWI things were wound back down to a peace time level, things on many fronts were allowed to relax, many of the lessons learned were gradually forgotten, and military doctrine suffered.
The 1920's
The Enigma machine was invented for use in secure banking by Arthur Scherbius in 1918 but it did not enjoy a meteoric rise in popularity, the German Military saw a use for the machine and started to develop it for their use.
As the buildup of German military power became evident in the 1920's, Poland trapped between two powerful nations, Russia to the East and Germany to the West became more than just interested in gathering intelligence on their possible future adversaries. From around 1928 the Polish secretly began to intercept radio transmissions, these intercepts were later found to be Enigma enciphered radio transmissions.
The 1930's
Polish Intelligence had acquired examples of the commercial version of the Enigma machines, but found that the German radio intercepts were not using this version. Unable to break the messages they decided to approach the problem from a unique angle, using mathematics to attack the cipher. Three young Mathematicians were recruited to the task, Marian Rejewski, Henryk Zygalski and Jerzy Rozycki. Polish Intelligence were helped by the French in 1931 and 1932, French cryptographer Gustave Bertrand received information about the German Enigma from a spy, Hans-Thilo Schmidt. The information gave vital clues and with the brilliant imagination of Marian Rejewski in guessing the wiring of the keys to entry disc of the rotors, this gave them a great leap forward. This was not the end of the tale but just a good start.
By 1938, the Poles were reading some 75% of the intercepted German Radio transmissions enciphered using the Enigma machine only the Poles knew about their success. It is said that in the period of access they had read over 100,000 intercepts. Then in 1938 the Germans added another two rotors to the existing three making it possible to chose any three of five rotors. The added complexity of the possible permutations made the task of recovering the keys too difficult for the Polish Code Breakers, with the resources they had at their disposal.
Bletchley Park 1938
Fifty miles (80km)
north-west of London lies Bletchley Park.
In September 1938, the Government Codes & Ciphers School visited Bletchley Park to ascertain its suitability for use in case of War, under the cover of Captain Ridley's shooting Party.
In July 1939 the Polish code breakers aware that invasion was imminent, decided that they needed to share the information that they had amassed with other countries to continue the effort during the coming years of war. A meeting was arranged with the French and British code breakers in Kabackie Woods near Pyry just outside Warsaw. To the utter amazement of the French and British code breakers, The Polish Crypt-analysis's gave them copies of the German Enigma machine and revealed the details of the Cyclometers, Bombas and Zygalski sheets. Dilly Knox was inquisitive about the key to entry disc wiring and to his surprise and amazement was informed that the Germans had wired it A-1 and B-2 and so on. This was something that could have been made much more difficult and had not been guessed by the British.
In August 1939, the Government Codes & Ciphers School (GC&CS) moved in at Bletchley Park just before the outbreak of War. MI 6 were using the site also as a radio centre for it's agents hence the title Station X, this was the tenth in a series of stations setup for this purpose.
Shortly before the invasion the Polish were ordered to destroy all of the equipment and information they had on Enigma, they then made their escape from Poland through Romania and made their way to join the French team at Chateau Vignolles just outside Paris. The British were now working hard on the problem of setting up Bletchley Park for the task ahead.
It was decided to
recruit mathematicians and the first was Peter Twinn followed by Alan Turing who
had made visits to GC&CS in London in 1938. These were soon followed by
Gordon Welchman and John Jeffreys.
Now that the British had the Enigma wheel internal wirings, as supplied by the
Polish, work could begin on solving the base settings of the Enigma and the
message keys. Many more tasks were required to be undertaken as part of the
overall work on breaking Enigma.
Alan Turing visited the joint French and Polish effort at Chateau Vignolles in December 1939 carrying with him the modified Zygalski sheets from Bletchley Park. Thus in early January 1940 the joint Polish - French team first broke back into Enigma.
Then on 14th January 1940, Dilly Knox's team made their first break into Enigma in the Cottage at Bletchley Park
It was found that the initial assumption, that the intercepted messages were German Army messages, was in fact incorrect, and they originated from the German Air Force. Once these first breaks had been made it was possible to search for errors within the operating procedures and practices of the Germans, to enable the simplification of tasks in aiding the breaking procedure.
The various messages that were repeated to different services i.e. weather reports could be used to create cribs. The laziness of the operators in selecting the starting positions of the rotors and many other factors all aided the efforts of the the code breakers. What was an unbreakable cipher was compromised by these errors and made the breaking of Enigma possible.
The copy of a German U-Boat used in the film Enigma, this was controlled by divers inside! In the background through the trees Hut 4 Naval intelligence and the Mansion House can be seen.
Walking around the North side of the Mansion you will find the Bletchley post
Office and Toy Exhibition enterance.
Continuing on to the rear of the mansion a view of the castellated water tower becomes visible.
This is Station X, not the whole building just the bit of the water tower that you see in the picture. The radio station through that window is very small and can hold just about two people. More on Station X later.
Station X
The Old Gate entrance to the rear of the Mansion where the dispatch riders, up to 400 of them a day would enter the site to deliver the intercepted German radio signals from places like Beaumanor Park. The signals were sent over Teleprinter lines for speed but the original were also delivered to safeguard against any errors being introduced by typing errors in the copying of the messages.
The Clock Tower and entrance to the court yard where the cottage that was occupied by the original code breakers in 1939 stands. On the left are the garages.
Code Breakers Cottage
The Memorial to the Polish Code Breakers
View across the old tennis courts towards the "Huts"
Lots more to come on this subject soon!