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Bletchley Park – Code Breaking Facility

 

An author’s perspective on the journey to complete the book


My first visit to Bletchley Park was in 1998 and it was a complete eye opener. The visit started with an on site lecture, and this proved to be invaluable in providing much of the background to the museum. I remember prior to the visit reading that before 1974 the whole place was shrouded by secrecy, by the Official Secrets Act. In 1974 the book, "The Ultra Secret", was published, the first volume of the use of British Intelligence in the Second World War. It brought to light the use, and impact of the Enigma-derived intelligence on the Allies'conduct of the war .

 

When the Ultra secret was finally brought out of the official secrets acts there was much discussion on Ultra's impact on the war. German military commanders were presented Ultra, and they derived that  the war would have ended in 1947-48 had it not been for Ultra.

 


The importance of Bletchley Park was almost lost to history as the story was kept under wraps. The fledgling museum was saved from the wrecker’s demolition ball. A handful of enthusiasts, who recognized the landmark importance of the site, prevented the sell off to developers. When the museum opened it was run on a tight budget and over a 10 year period the museum was preserved, renovated and restored. Many of the wooden huts were in very poor shape. The project encouraged ex-intelligence workers to join the project, and many brought back their stories and numerous artifacts flooded back.

Bletchley Park Mansion

 

Bletchley Park Mansion

 


My second visit to Bletchley Park was in 2008 to gather research information for the second Churchill book in the series. The focus was around the early days of Bletchley between the Battle of France and Battle of Britain, and the initial successes in cracking Enigma. The German military command had developed the Enigma cipher machine to keep their communications secret for their army, navy and air force. The electro-mechanical machine was available commercially during the 1920s and it was evolved for military use. The machine relied on a series of rotating 'wheels,' rotors to translate text messages into complex ciphers. The machine used many billions of combinations to set its variable elements. If the receiver had keys to the machine they could unscramble the message. The German authorities believed in the absolute security of the Enigma right to the end of the war. Only Admiral Donitz ever suspected a breach.

 

The first breakthrough in cracking the code came through in the 1930s with Polish cryptographers who worked with commercial machines. From June 1934 they were able to read German coded messages like these about from the SS and Gestapo about the Night of the Long Knives. They were able to read about 75% of the intercepted messages until 1938. Every so often some changes were introduced to the coding systems but the Poles were able to keep up with these.

 

In July 1939 Polish cryptographers shared their Enigma work and results with the French and British. They had obtained examples of the commercial Enigma machine and managed to break the codes. They also had an idea for developing a mechanical method for finding the Enigma ring settings to speed up deciphering.


 


In his book The Hut Six Story: Breaking the Enigma Codes  Gordon Welshman, a former Bletchley codebreaker,  unequivocally states that the British Ultra "would never have gotten off the ground if we had not learned from the Poles, in the nick of time, the details both of the German military Enigma machine, and of the operating procedures that were in use."

 


The Polish work gave the Bletchley organization a great boost, and in January 1940, code-breakers in Hut 6 made their first break into Enigma. But Bletchley Park was still a fledgling and manual operation, very laborious, and it was hit-and-miss whether the messages could be deciphered before an event would actually happen. An electromechanical machine could greatly reduce the odds, and thereby the time required, to break the daily-changing Enigma keys. Work started on this under the leadership of the renowned Alan Turing (father of the Turing Machine and pioneer of computing).


 

Enigma machine open with 8 rotors 

Ciphers or Encrypted Messages

Polish Enigma Recreation

 

Enigma in the field

Enigma Usage Enigma Usage
Enigma Usage

Enigma Usage


"Knowledge is power." A recent quote, or is it? Well, it was actually coined in 1597 by Sir Francis Bacon, English author, courtier and philosopher. In the military, knowledge has always been important, especially in decision-making. In recent decades, knowledge, better known as "intelligence," has emerged as one of the most vital military assets.

 

Although we may perceive the concept of military intelligence as old as warfare itself the industrial production of intelligence dates back to May 1940, in response to the demands of a nation in crisis. Bletchley Park witnessed the first real, concerted effort to introduce mechanization and a level of automation into the production of intelligence.

 Y stations Equipment


During the Battle of France in May 1940, the value of deciphered enemy communications started to emerge, especially from the German Army when field commanders filed situation reports to headquarters each day. This allowed the British commanders to check on their own information and build up a more accurate picture. This gave great confidence in the potential of this intelligence and greatly raised Bletchley's profile with the military.

 

In May 1940, several new prototypes of electromechanical machines, or Bombes, were completed, based on the original Polish idea, and initial results proved very promising as the operation of deciphering dramatically sped up. If messages were decrypted in a 24-hour window, this would provide invaluable information on enemy intent and threats, and allow defensive positions to be taken prior to any enemy offensive. The odds against breaking Enigma were a staggering 150 million to one, so it was unlikely this source of intelligence would come under suspicion as it was considered highly secure by the Axis.

 


Churchill had to use the limited resources he had at his disposal in the most effective way. He could only do that through the greater use of organizational and enemy intelligence. Knowing the extent of enemy preparation and activity would provide the necessary insight to where and how the enemy was likely to strike next. Armed with this, Churchill could then better target resources to meet the invasion threat.

 

Churchill knew the value of intelligence and was shaped by his previous experiences from the First World War. First, the lack of a central policy undermined coordination of resources and prolonged the UK's response as well as the war. Second, the lack of reliable intelligence proved a major undoing for him at Gallipoli in 1915, which crucified his career in the short term. Churchill's plan to defeat Turkey by sending in British warships and troops to stand off Constantinople failed miserably. As the troops hit the beaches at Gallipoli, without adequate ground intelligence, they had nowhere to go and were gunned down by the Turkish army that commanded the heights and overall terrain of the beaches.

 

As Churchill came to power in May 1940, he became aware of the secret establishment at Bletchley Park, which collected and deciphered encrypted enemy communications or Enigma codes under the overall command of Stewart Menzies, the director of Military Intelligence (MI6). Bletchley Park was opened in 1938 when the Government Codes & Ciphers School was moved there to test its suitability for warfare. The mansion was located midway between the Universities of Oxford and Cambridge, a fertile community and source of mathematicians and logicians, all ideal code-breaker candidates. Bletchley Park, commanded by Alastair Denniston, was given the cover name Station X, being the tenth of a large number of sites acquired by MI6 for its wartime operations.

 

Churchill was made aware of Bletchley and quickly recognized its potential. The necessary investments were made to further automate and scale the operation up. This was done through more Bombes and the influx of skilled staff into Hut 3, which dramatically optimized the operation. The operation was given the code name "Ultra," and then shrouded in a veil of security. A network of listening stations called "Y" Stations was set up to gather raw wireless signals for processing at Bletchley. The focus at Bletchley was not just on breaking the Enigma code, but as the volume of messages increased, putting a significance or priority on key messages going to chiefs of staff and Churchill. This proved extremely valuable for the recipients. However, a new cog in the operation was required, namely an interpretation unit, known as the Shadow OKH (German Army High Command) in Hut 3, which required the influx of skilled human resources. The emphasis was on pooling this information with previous messages to create an enormous bank of organized knowledge.

 

Battle  of France

 

Operation of Bombe Bletchley Park Hut 3 secret war 

Bletchley Park Hut 3    Bletchley Park Hut 6

  Bletchley Park Hut 6 letterscircled

Bletchley Park System

Bletchley Park Hut 8

 As a result of these initiatives:

 

  • An elaborate level of security was developed to protect Ultra. Special Liaison Units were set up to ensure that Ultra was only put into the hands of a few key decision-makers to lower the risk of the Axis discovering the source of the intelligence.
  • Ultra intelligence and knowledge could be applied to decision-making, specifically in the War Cabinet and through RAF Fighter Command.
  • Secure direct lines and SLUs were set up to RAF Fighter Command (Bentley Priory) for the use of Air Chief Marshal Hugh Dowding.
  • Ultra gave Dowding details of the Luftwaffe order of battle down to individual commanders in the field. The output framed the messages in the larger context of what was happening on the enemy front.
  • Churchill took a deep personal interest in Bletchley and described it as "the goose that laid the golden egg, but didn't cackle."
  • To help ensure that Ultra was being used effectively, Churchill introduced the systematic use of it across his enterprise (all three military arms). In some situations, he was outraged when his commanders did not use it.
  • An elaborate decoy system was set up so if actions resulted from Ultra, the Axis had to be fooled into thinking that the source of intelligence came from elsewhere but Ultra.
  • Ultra was arguably the first concerted efforts to introduce Knowledge Management on such a large scale.

Bombe Rebuild Project Bombe
Bombe Rebuild Project Rotors

Colossus Rebuild Project


Electromechanical computers would be incorporated into the process of information gathering, collection, collation, deciphering and interpretation. Within an incredibly short time frame, Bletchley Park revolutionized modern warfare, specifically, how air wars were going to be fought from that point on.

 


In the short term, Ultra had a profound effect on the UK's defense strategies and the course of the Battle of Britain by providing early warning of enemy intent, strength, size of raids and their timing. For example, RAF Fighter Command was aware of massive enemy attacks (i.e., Eagle Day - August 13, 1940), and any changes in enemy tactics. Storey's Gate was receiving 200 to 300 decoded messages a day and passing a synopsis to Dowding. In the longer term, the overall knowledge-driven culture had a profound effect on the course of the war.