The Secrets of Station X: How the Bletchley Park Codebreakers Helped Win the War

By Robbin Laird

There is by now a growing literature on Bletchley Park, its culture, its approaches, and its roles in helping the British and then the allies win the Second World War II.

The book by Michael Smith first published in 2011 which focuses on Bletchley Park is clearly one of the very best and is highly recommended.

He has interviewed many of the Codebreakers who worked at Bletchley and clearly has provided to the reader a sense of how the place worked as well how it functioned in a broader context.

But beyond the power of providing real understanding about Bletchley Park he has provided significant insights into the cultural and operational problems of providing what we would now call situational awareness or the I in C5ISR, or perhaps best put, actionable intelligence.

The first point, which might be noted, is that the demands of the war attracted a very unusual mix of talent to the code braking business.

If we would put that in modern terms, would a US intelligence community today tolerate the kinds of backgrounds and personalities, which Bletchley put together?

The book provides vignettes throughout of the wide range of people and their backgrounds involved in the Bletchley process

And when one reads through the book, I can not imagine many of these types ever getting a security clearance in today’s world of intelligence in a liberal democratic state.

For example, here is the judgment of one member of the air section at Bletchley,

Gwen Davies, another member of the Air Section, remembered Cooper as being ‘a very, very strange man, who would burst into the watch sometimes and shriek something absolutely unintelligible and burst out again.

Most of the junior members of staff had difficulty understanding what he was saying, but there was no doubting his brilliance.

There was a great degree of tolerance at Bletchley for eccentricities. There had to be because so many of the people were very, very eccentric indeed. At least half of the people there were absolutely mad.

They were geniuses, no doubt many of them were extremely, extremely clever, but my goodness they were strange in ordinary life.1

The second point was the level of cultural innovation as the Park evolved over time to adjust to the demands of the war.

And to do so with a high level of flexibility with regard to how work became organized as well.

An American who came fairly early to liaison with the British at Bletchley highlighted the dynamics from an organizational point of view at the Park.

Joe Eachus, a young US naval lieutenant, was sent to Bletchley in early 1942 by Op-20-G, the US naval codebreaking unit, to find out more about the British codebreakers and what they were doing.

‘My nominal task was to tell Washington what was happening at Bletchley Park,’ he said. ‘In that role I got around to see more of Bletchley Park than a lot of the people who were part of it.’

There was continuing mistrust on both sides.

As a liaison officer I was occasionally asked to get specific stuff and on one occasion I was asked by Washington for an organisational chart of Bletchley Park,’ Eachus said.

‘I went to the man in charge and said could I have a chart of the organisation. He paused and said, “I don’t believe we have one.” I didn’t pursue this with him, but I was never quite certain whether he meant we don’t have a chart, or we don’t have an organisation.’ 2

The third point, which is really at the heart of the book, is the evolution during the war of how intelligence and operations became more closely integrated.

For a considerable period of time, the UK services simply were not aware or in the case of higher-level leadership simply discounted the utility of what Bletchley was producing.

On the one hand, the challenge was to protect the enigma data being mined from discovery of this process by the Germans.

On the other hand, there were the significant cultural gaps between the processes and product of Bletchley and the services.

An additional problem of course was to the ongoing challenge of being able to deliver the right intelligence to the right decision makers on a timely basis, a challenge which is increasingly facing the 21st century warfighter.

But finally by the time of the African campaign in 1942 it was clear that Bletchley could deliver war winning intelligence.

North Africa was where Ultra finally proved itself to be the source of intelligence the military could trust.

Until then, the RAF and the Royal Navy had derived real benefits from the Enigma decrypts and understood their importance.

The Army had placed a lot of trust in its eventual value, providing the bulk of the intercept operators who intercepted Enigma messages and many of those who worked on them at Bletchley, but had been slow to see the tangible value the Ultra reports could provide.

That changed in North Africa, said Lucas.

From the summer of 1941 until the surrender in Tunisia in May 1943, a very large part of our work was concerned with North Africa, where it may be said without hesitation that ‘Source’ was decisive.

This was because, at long last, efficient arrangements had been made for passing our information to those who could best use it, the operational commands.

Partly in consequence of certain differences in the character of War Office and Air Ministry, partly because of the scantiness of military, as compared with air, intelligence from Hut 3, relations with these two ministries also differed.

While Air Ministry looked to BP for their most important source, the War Office received comparatively little. They therefore treated Hut 3 as a very subsidiary source.

It was not until the African campaign that Hut 3 established itself in the eyes of the War Office as a purveyor of goods which were priceless, unobtainable elsewhere, and already well processed when issued.

In the African campaign, every formation, every unit, had been known and placed, no reinforcement could accrue to the enemy across the Mediterranean without due warning.3

Even then high-ranking commanders would ignore what they could have known because their “intuitive” knowledge was superior to anything an organization which Bletchley could provide.

And, of course, there was the challenge of what tentative intelligence might show which contradicted the core assumptions of commanders which led of course to discounting the incoming intelligence.

One of the more compelling cases which Smith highlights in the book was the clear conflict between the intelligence which was coming in with regard to a German counter-attack which would lead to the Battle of the Bulge and the clear assumption which senior commanders like General Montgomery had with regard to the impending collapse of the German forces.

The warning signs that the Germans were planning a major counter-attack were not as obvious from Ultra as they had been at times during the war.

Nevertheless, there was no failure of intelligence collection, simply a lack of long-term analysis of German intentions born out of the belief that the war was virtually over, said Ralph Bennett.

The high-ups on our side became convinced that the Germans were weakened by their failures and they couldn’t do anymore.

By that time we’d got too damn cocky. I still don’t understand and I don’t think I shall understand, how it was that sign after sign that they were planning something was ignored. 4

The fourth point is how Bletchley worked intelligence gained from German allies with regard to German capabilities and intentions.

Throughout the book cases are provided of how the Italians and Japanese inadvertently provided key intelligence to the Bletchley team.

A most dramatic example was leveraging Japanese intelligence to get a very complete picture of how the Germans were preparing their defenses for the Atlantic Wall.

The Japanese Military Attaché cypher had been broken by John Tiltman in 1942. Bill Sibley was one of the Japanese interpreters translating the Japanese Military Attaché’s messages. I was recruited from Balliol (I was a classicist, at the end of my first year) for the second Japanese language course at Bedford, which began, I think, in September 1942.

We were summoned to a five-minute one-to-one interview with John Tiltman, having been pre-selected by the Master of Balliol A. D. Lindsay. I then went to Bletchley in the spring of 1943 and was set to work as a translator on the Japanese Military Attaché code until the end of the war, apart from a period of a few months when I was seconded to work on the Japanese Naval Attaché cypher.

Our work began after the real cryptographers had done their work and identified where, in relation to the double substitution cypher keys, individual messages were located. The texts on which we worked were provided for us by ‘key-breakers’ who were not trained in the language, and whose task was to break the keys used in the messages relying on acquired familiarity with the frequencies of the bigrams in which the messages were composed before being encyphered.

We lived an introverted existence, insulated from the real world.

Our masters did occasionally send us words of encouragement, but I can’t recall that at our level we were ever told of any examples of our work having produced any positive results. Nobody knew what was going on in the rest of the place.

It was a funny life, very funny, particularly the secrecy, and the oddity of some of the people. There was one famous professor of English who used to read about three detective novels a day. He used to walk around the grounds reading them.

The codebreakers added to the significant intelligence they were already providing to Allied commanders when they broke into the Fish link between Berlin and von Rundstedt’s headquarters at St Germain, just outside Paris. The Germans had increased the security of Tunny, introducing the SZ42, but the arrival of Colossus in early 1944 led in March to the breaking at Bletchley of the Paris–Berlin link, which they codenamed Jellyfish, decyphering all of von Rundstedt’s high-grade communications with Hitler.

The confirmation from the Japanese ambassador’s report, and other signals decyphered by Bletchley, that the Germans believed the Allies would land on the Pas de Calais led the Double Cross Committee to use the double agents to send false intelligence to the Germans that would reinforce them in that view, ensuring that large numbers of German forces were kept there and cutting the numbers that would face the Allied troops in Normandy.5

A fifth point sketched throughout the book was the challenge of working with allies, notably the Americans, who benefited greatly from Bletchley but as the war went on provided increasingly significant intelligence contributions.

The problem of course was cultural and levels of trust, rooted in two very different systems of developing, using and protecting intelligence.

Again, this challenge is very central today as more allies need to work together to deal with the global threat of terrorism and even more pointedly dealing with direct Chinese, North Korean and Russian threats.

Eventually agreements were worked out and processes of sharing forged.

A US mission went to Britain in April 1943 and was involved in ‘difficult and protracted negotiations’ with Travis and Menzies.

But in mid-May, the two sides signed a groundbreaking accord.

The BRUSA agreement set out a division of responsibilities between Bletchley Park and Arlington Hall. The British would control the interception and decryption of German radio messages while the Americans concentrated on Japanese. US liaison officers would be based at Bletchley Park where they would have access to ‘all decoded material’ and the right to pass those they selected back to Washington or on to US commanders in the field.6

The Russians also benefited from Bletchley as well by having a well placed source in the process.

Of course, we are talking about a spy working for the Russians in the thick of the Bletchley process, something which would become evident after the war.

John Cairncross, codenamed Liszt by the Russians because of his love of music, had already given Moscow Centre details of Bletchley Park’s network of intercept sites while working in the section of the Treasury that dealt with the GPO in the months before the war.

He had then become private secretary to Lord Hankey, the Minister without Portfolio, and passed the Russians details of the Anglo-American atomic weapons project, providing them with the information that formed the basis for their own atomic weapons programme.

But at the beginning of 1942, Cairncross was called up and was instructed to try to get himself into Bletchley Park, which the KGB codenamed Kurort (German).

…..Cairncross smuggled decrypts that were due to be destroyed out of Hut 3 in his trousers, transferring them to his bag at the railway station before going on to London to meet his KGB contact.

The information that he handed the Russians is probably rightly credited with helping them to win the Battle of Kursk, the turning point on the Eastern Front.

Despite the fact that a sanitised version of the Tunny messages was being passed to Moscow, Stalin was highly suspicious of any intelligence passed to him by the Allies, particularly if the source was unclear.

But Cairncross was supplying the German language signals and it was coming via the KGB.

‘The Russians were convinced,’ Cairncross said, ‘that in its German version the Ultra I supplied was genuine, giving the full details of German units and locations, thus enabling the Russians to pinpoint their targets and to take the enemy by surprise.’ 7

A final point, which I would highlight, is the introduction and evolution of the man machine relationship which is now at the center of C5ISR which was born at Bletchley.

As the work processes evolved and standardization sorted out with regard to those processes some of the processing was now handed to what would become the first computers.

Chapter 10 of the book entitled “The Birth of the Modern Computer” provides an overview of the process of introducing new machines into the intelligence process.

In short, Smith provides a very readable account of Bletchley Park. It is one which is not a quick read, less for any failure in clarity in writing but because of the details throughout the book which one wants to take in and process.

And as I have highlighted here, Bletchley Park is a history but also a case study of the challenge of shaping actionable intelligence which goes against the grain of what leaders want to hear.

Many of our intelligence organizations are more centered on themselves and their culture than they are really being open to learning what they do not know.









  1. Smith, Michael. The Secrets of Station X: How the Bletchley Park codebreakers helped win the war (Kindle Locations 1288-1294). Biteback Publishing. Kindle Edition.
  2. Smith, Michael. The Secrets of Station X: How the Bletchley Park codebreakers helped win the war (Kindle Locations 2301-2308). Biteback Publishing. Kindle Edition.
  3. Smith, Michael. The Secrets of Station X: How the Bletchley Park codebreakers helped win the war (Kindle Locations 3184-3199). Biteback Publishing. Kindle Edition.
  4. Smith, Michael. The Secrets of Station X: How the Bletchley Park codebreakers helped win the war (Kindle Locations 4085-4093). Biteback Publishing. Kindle Edition.
  5. Smith, Michael. The Secrets of Station X: How the Bletchley Park codebreakers helped win the war (Kindle Locations 3786-3806). Biteback Publishing. Kindle Edition.
  6. Smith, Michael. The Secrets of Station X: How the Bletchley Park codebreakers helped win the war (Kindle Locations 3649-3654). Biteback Publishing. Kindle Edition.
  7. Smith, Michael. The Secrets of Station X: How the Bletchley Park codebreakers helped win the war (Kindle Locations 343-3548; 3556-3562).Biteback Publishing. Kindle Edition.