How British engineering icons changed espionage in two world wars

Much of the success of gathering intelligence, secure communication and espionage during the turmoil years of the First and Second World Wars was down to technology and engineering.

E&T interviewed Dr Elizabeth Bruton, curator of technology and engineering at the Science Museum, London. 

E&T: How did electrical engineers become of growing importance to the gathering of intelligence and espionage during the world wars?

Elizabeth Bruton: Electrical engineers had a key role in gathering of intelligence and espionage from the First World War onwards, even if, as far as we know, relatively few of the codebreakers at Bletchley Park had an engineering background or were members of the IET.

Initially, during the First World War, when we started to see an increased professionalisation in codebreaking, they used people who had expertise in linguistics. Back then, they felt it was their best bet to break codes and ciphers. It was largely pen and paper. It was all about understanding the language. By the late 1930s, the Polish Cipher Bureau realised that an increasingly automated cypher system would help. Enigma was first developed as a civilian cypher system in the early 1920s. Later, it was purchased by the German military for exclusive use.

It was then that the cypher machines, with automation of the process, became less about language and more about math. The Polish Cipher Bureau were the first cipher organisations to use mathematicians to break codes and ciphers and did so from the 1920s onwards. Quite a few of the codebreakers working at Bletchley Park were mathematicians and there were people from diverse backgrounds working.

E&T: Tell us about Tommy Flowers – an English engineer with the British General Post Office (GPO) – so crucial for British intelligence. Tommy Flowers was a student member of the Institution of Electrical Engineers (the IEE, now the IET). The IET archives team confirmed that he joined in 1928 and was still a student member in 1930. Due to the changes in membership levels at the IEE, Flowers’ membership level was changed from Member to Fellow in 1945.

Bruton: While the stories of Alan Turing and Gordon Welchman are pretty well known, we aimed for the lesserknown collaboration between Bletchley Park and electrical engineers, including Tommy Flowers, at the Post Office Research Station at Dollis Hill. Together, they produced the first semi-programmable electronic computer, Colossus, in 1944 and used it to break high-grade German cipher systems such as Lorenz.

‘Electrical engineers had a key role in gathering of intelligence and espionage from the First World War onwards, even if relatively few codebreakers at Bletchley Park had an engineering background.’

To break German cipher systems, two separate developments took place at Bletchley Park. Firstly, the so-called Bombe machine, a code-breaking machine based on the work of Polish codebreakers and further developed by Turing and others, used during WW2. It was an electromechanical system used to find the key for Enigma cypher device messages.

Enigma was a German cypher system used for day-to-day communications between all military branches, including the German Air Force (Luftwaffe), the Navy and Army. However, they also used other cypher systems such as the Lorenz, a much more complicated system that was used for high-level command.

If breaking into Enigma exposes what the military is doing on a day-to-day basis, breaking into the Lorenz cypher exposes their strategic, longerterm thinking and their long-term military strategy. This was the task of codebreakers at Bletchley Park in 1941.

They soon realised that the process needed to be automated – automated far beyond the scope of the Bombe machines, that they already had in place, which could only be applied to Enigma messages and was based on the pre-war work of Polish codebreakers. Bletchley Park started to collaborate with the GPO.

In January 1944, the first Colossus machine was brought to Bletchley Park and operated a month later. Flowers was one of the leading electrical engineers who worked on the device, which became the world’s first electronic semi-programmable computer. 

This system was in use from early 1944 onwards and helped break the Lorenz [cypher] messages sent around at the time of D-Day. It helped to expose, for instance, that the German military had fallen for a British counterintelligence ruse, that the D-Day landings in Normandy would only be one of several landings. As a result, the Germans held some of their troops and tanks back, waiting for a landing that never took place.

E&T: Tell us about the first radar-like system used in the First World War and its engineer, later an IEE member, who came up with it. Captain Henry Joseph Round, later an IEE member, was a pioneer in using electronics and the first to master using the wireless direction-finding system for gathering intelligence.

Bruton: Captain Henry Joseph HJ Round (1881-1966) was a Marconi Company engineer, specialising in wireless communications, such as pointto-point communications using electromagnetic waves. He started his work before WW1 developing ‘radio valves’, also referred to as ‘vacuum tubes’. These looked like lightbulbs and were based on lightbulb technology.

They could be used to detect electromagnetic waves and they could be used to amplify electrical signals. He realised this technology could be used for voice communication, but first it was used for ‘wireless direction finding’. We explored this in the Top Secret exhibition.

We had a WW1 wireless direction finder from the Marconi Collection at the History of Science Museum, Oxford, on display for the exhibition. Wireless direction-finding technology was used to defend the home front during the First World War, then one of the first wars, where the home front came under direct attack during a significant war.

Aerial attacks from German Zeppelin airships, and later Gotha G.V., a heavy bomber used by Imperial German Air Service, attacked the home front.

Captain HJ Round pondered ways to protect Britain from aerial attacks. Now assigned to military intelligence, he suggested the system of wireless direction-finding stations.

Wireless receiving stations were to be dotted around Britain’s coastline, such as on the east coast, under attack over-proportionally. They would intercept wireless signals, via Morse code signalling, sent from German airships to locate them.

If three or more stations could intercept the same message, they could triangulate where the signal was coming from and pinpoint where the German airship was located.

It wasn’t about the content of the message, it was about the location of the message and so defending the British home front from attack from the war. The Imperial War Museum has a photograph of the direction-finding operations room in Horse Guards in London from 1917.

If you didn’t look too closely, it could be a similar Fighter Command tracking station in the Second World War. The tracking and intelligence-sharing system was largely the same in both wars, even if the source was wireless direction-finding in the First World War and radar in the Second World War.

Essentially, it can be thought of as the radar of the First World War in terms of the intelligence received. Radar emits an electromagnetic signal, which is essentially bounced off an object, mostly aircraft in the Second World War, to reveal the object’s location. Wireless directionfinding requires intercepting a wireless message to reveal the object’s location. Despite these limitations, wireless direction-finding was quite successful.

An air defence control room in central London allowed triangulating and tracking of German airships. In 1916, this advanced warning system could send British pilots up to shoot them down. In early September of the same year, lieutenant William Leefe Robinson of the Royal Flying Corps managed to shoot down the German woodenframed Schütte-Lanz SL 11 airship over Hertfordshire, the first time such an aircraft was shot down over Britain.

Thousands of people were said to have cheered at the sight. From late 1916 onwards, the wireless direction-finding stations continued to be incredibly successful in detecting when German airships were coming in over the east coast of Britain [and allowed for] preparing defences against them.

Captain Round submitted a paper to the Institution of Electrical Engineers in 1919, where he talked about wireless direction-finding and how it was used during the war. After the First World War, Round was a key figure in the development of broadcasting technology.

The vacuum tubes that he was working on for wireless destruction finding and voice communication during the war was used for very early radio broadcasting in the 1920s. You can see a narrative that connects his pre-war work to his wartime work and then the early history of the BBC.

‘Today, companies like Google and Facebook and social media companies are almost forming part of the intelligence landscape.’

E&T: Tell us how a single engineer kept military field communication secure for nearly three decades.

Bruton: Major-General Algernon Fuller [an associate member of the Institution of Electrical Engineers] worked in the military for most of his life and was a telecommunications specialist. During the First World War, Fuller developed a system called the Fullerphone. [His invention was of] life and death importance for secure communications.

At the start of WW1, Britain was using a very crude field telephone for frontline communications. The Germans regularly intercepted it. There were leaks of battle plans, and it led to the loss of life at the battlefront. In response, Fuller developed the Fullerphone, which used a very low-voltage DC current, which meant messages sent using Morse code were entirely secure and voice communication by telephone was very hard to intercept.

The Fullerphone could also be used on very poor or damaged telephone lines. Fuller was able to patent the device, unusual for the time, allowing him to commercialise it. The technology continued to be used in the British military, in France and the United States throughout the rest of the First World War and even during the Second World War, its use spanning nearly three decades.

E&T: In your opinion, what changed since the early days when the aforementioned electrical engineers got involved in espionage and intelligence work since the First World War?

Bruton: If we can learn one thing about electrical engineering and intelligence, then that’s that it’s ultimately a collaborative endeavour. It involves many people, rarely just the single person that receives recognition. It can also be hard to discover the identities of people working in or with intelligence, especially after the Second World War. These people might still be alive today and so have their identities kept secret and protected due to the important and often secret work that they do. This includes electrical engineers working in intelligence as well as more traditional codebreakers and so on. The landscape also changed.

It’s not really until we started to have the advent of the internet, and the World Wide Web, and cyber security, that it’s now a completely different communications landscape.

Today, we see organisations like Google and Facebook and social media companies involved. They are almost forming part of the intelligence landscape, broadly and generally defined. We, as individuals, are very much part of the conversation too, as our data and communications are now, essentially, part of this new, general intelligence landscape.

It is also a much more open and accessible world of communications. Almost all of us use smartphones and encryption and have Internet of Things smart devices in our homes. And so cyber security is important to most people and businesses when historically it was the preserve of governments, intelligence agencies and the military.

Electrical engineers developing smart devices or working in cyber security play a very important and public role in our relatively new communications and intelligence landscape today. It’s great to see the IET getting involved and organising more events and training in cyber security and building awareness of career opportunities in cyber security, now and in the future.

Dr Elizabeth Bruton is curator for ‘Top Secret: From ciphers to cyber security’, a free exhibition at the Science and Industry Museum, Manchester, from 19 May-31 August 2021.