Geek's Guide

Bletchley Park remembers 'forgotten genius' Gordon Welchman

Head of Hut Six 'a disastrous example to others' – GCHQ

By Alexander J Martin


An exhibition has been launched at Bletchley Park to commemorate the work of Cambridge lecturer and "forgotten genius" Gordon Welchman at Britain's wartime codebreaking centre.

Titled Gordon Welchman: Bletchley Park's Architect of Ultra Intelligence, the exhibition is based on the book of the same name by the great man's biographer, Joel Greenberg, and opened on Friday to encourage public recognition of the wartime work of an unsung hero.

Despite Welchman's "invaluable" contributions to breaking Enigma, he has received less public applause than Alan Turing, his colleague both at university and Bletchley.

Welchman adapted Turing's Bombe designs to create the workable machine for decrypting German military messages through a device known as the "diagonal board". He also established and headed Hut Six, which decrypted more than one million German messages over the course of the war.

At the launch event last Thursday, Greenberg stated that it was Welchman who had founded Bletchley Park's production model for decrypting at scale, and developed the practice of producing intelligence through traffic analysis – a specialty of Hut Six.

The analysis programme, named "Sixta", was a fusion of traffic analysis and cryptography. In a personal paper titled A Personal Record, written shortly before his death in 1984, Welchman stated:

No-one else was doing anything about this potential goldmine; so I drew up a comprehensive plan which called for close coordination of radio interception, analysis of the intercepted traffic, the breaking of Enigma keys, and extracting intelligence from the decodes.

In 1982, Welchman – in his book, The Hut Six Story – published more details of the traffic analysis the Bletchley-based codebreakers had committed. The details provided led to Blighty's eavesdropping nerve centre GCHQ describing him as "a disastrous example to others", and Greenberg suggested the agency was particularly sensitive to the revelations of its traffic analysis programme.

Research papers on traffic analysis by the Government Code and Cypher School (or GC&CS, as GCHQ was then known) remain classified. Greenberg noted that upon his book's publication, Welchman – who eventually moved to America and became a US citizen – was targeted for prosecution under the same legislation as NSA master blabbermouth Edward Snowden.

At the time of its publication, Welchman was a consultant for the MITRE Corporation, which was working on communications security for the US Department of Defense. Welchman subsequently lost his security clearance, and therefore his consultancy role, and was prohibited from communicating with the media to discuss his work at Bletchley Park.

An exhibition notice states:

Welchman's vision for a secure tactical communication system can be found in the Joint Tactical Information Distribution System (JTIDS).

This is a fully operational command and control system, providing information, distribution, position, location and identification capabilities for the US Air Force, Army, Navy, Marine Corps, and British, French and NATO forces.

Gordon Welchman died on 8 October, 1985 at the age of 79 at Anna Jacques Hospital in Newburyport, Massachusetts.

The Ultra Secret

Almost nothing was known about Bletchley Park's role in the war until the 1974 publication of The Ultra Secret, a book by former RAF officer Frederick Winterbotham, and it was only after this that Welchman began to feel comfortable about coming forward with his story.

Most of those who had worked at Bletchley were unaware of the work their colleagues in other huts had done, including spouses who had initially met there, and had been forbidden from talking to each other about it under the Official Secrets Act.

Bletchley Park Manor House

It was only following publication of the Winterbotham book, more than 30 years after the work had taken place, that many began to feel less restricted in talking about their personal war efforts.

Welchman's granddaughter Jennifer Welchman told The Register that her grandfather believed that Bletchley was an important story which deserved to be told.

His first wife's military family believed he had avoided military service, which contributed to the breakup of that marriage. Jennifer explained that he was "touched and hurt when the younger men at Bletchley were accused by friends and family of shirking military service."

She added: "My grandfather would be thrilled to see these people remembered".

"In some ways he did believe he managed to escape military service," Jennifer said. "He acknowledged that Bletchley Park was a very comfortable place to live, compared with what other men were experiencing."

Despite GCHQ's admonishments following the publication of his book, the Bletchley Park release states that Welchman's "wartime colleagues could not have thought of the codebreaker more differently [than that of the 'disastrous example' tagged on him by GCHQ], describing him in the late 1940s as inspiring, inventive and by one as 'one of the most original minds I have ever known'."

Uniform analysis

Among those who had worked under Welchman in Hut Six is 101-year-old James Thirsk, who attended the launch on Thursday.

Thirsk had initially been an infantryman but had applied for a transfer when a message was circulated for those with suitable qualifications to join the Intelligence Corps as an officer.

His party had been stationed at Beaumanor, where he told us he worked in uniform and didn't receive the suspicion that some other men reported. "If people asked I told them I worked for MI8 communications, which I did," he said.

"I really only have the one memory of Welchman," Thirsk told The Register. "We knew someone called 'Welchman' was in charge of Hut Six, but we never saw him, he didn't mix with us."

"Our party had been moved to Bletchley from Beaumanor in Leicestershire. We dealt with traffic analysis and callsigns – three letters identifying the German stations that were changed every midnight."

"We hadn't known that Enigma had been broken. It was in the middle of the war, Welchman gathered 50 men – we were only men then – and told us about Enigma."

Thirsk has published a personal memoir of his time at Bletchley, comically subtitled An Inmate's Story.

He told us that while his work at Bletchley didn't inform his later professional life as a librarian, his wife, whom he worked alongside on Hut Six's Sixta traffic analysis group, often credited her Bletchley experiences as a core skill in her later academic career.

Joan Thirsk, CBE, was an economic and social historian who worked at the London School of Economics and the University of Oxford. Her obituary in the Telegraph noted that she "was the leading agricultural historian of her generation and had a huge impact on her field in terms of methodology and research."

The exhibition opened following the broadcast of a BBC documentary on Welchman, subtitled Codebreaking's Forgotten Genius. The documentary was extensively recorded at Bletchley Park, and is available on the BBC's iPlayer. ®

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