Secrets of D-Day: Bletchley Park codebreakers

Bletchley Park
Pat Davies’ photo album. Credit: Bletchley Park

On the 80th anniversary of D-Day, Bletchley Park veteran Pat Davies looks back at her time working for Station X, the hidden home of the Second World War codebreakers

Words by Natasha Foges

Pat Davies, Second World War codebreaker

For decades, Pat Davies kept her wartime secrets to herself, not sharing her experiences even with her own family. In the Second World War, she was assigned to one of the war’s
most important operations: the ambitious attempt by Bletchley Park, centre of British intelligence, to crack the German Enigma code.

Before she had anything to do with Station X – the codebreaking HQ had its own codename, of course – Pat had heard of the Victorian mansion in leafy Buckinghamshire. Her godmother, married to a chap in the foreign office, wrote to Pat’s mother with news: some of the secretaries, a “crowd of jolly girls”, were going to work at a nice place called Bletchley Park and wouldn’t it be good if Pat went too? But it didn’t sound like Pat’s cup of tea: “I decided that I was going to join the Wrens [Women’s Royal Naval Service]
and be by the sea with a crowd of jolly sailors!”

But when she joined the Wrens in 1942, jolly sailors were not what they had in mind. When it was discovered that Pat could speak fluent German – thanks to her family’s Austrian refugee cook – she was sent for special training. “I was terrified I was going to be a spy – that would mean jumping out of an aeroplane. I was much too timid to do that.”

Bletchley Park
Bletchley Park

Instead, Pat was to work in close communication with Bletchley Park, intercepting messages sent by German ships in Enigma code and passing them to Bletchley to be unscrambled. She was posted to a Y station – a top-secret listening post – in sleepy Withernsea on the Yorkshire coast. “There was traffic that wasn’t too urgent from the Baltic,” she explains, “so you got run in quite well there.” She then spent a summer in Lyme Regis in Dorset, in a disused golf clubhouse, listening to German ships and lighthouses along the Normandy coast ‘talk’ to each other.

The Engima Machine

Bletchley Park
An Enigma Machine

Pat had signed the Official Secrets Act as soon as she finished her basic training, and discussion of her work was strictly forbidden. As a cover story – of sorts – she told people she was working in radio (“there were aerials all over the buildings so it wasn’t very difficult for anyone to guess”). Pat and her fellow Wrens were a crucial cog in Bletchley Park’s wheel. When a message was received in Enigma code, one of the Wrens would dash to the teleprinter and send it to Bletchley Park. “They always wanted the messages immediately,” says Pat. The race was on to stay one step ahead of the enemy: if the war was to be won, the Allies needed advance knowledge of German manoeuvres.

The code generated by the Enigma machines – five-letter groups of gibberish – had been considered impenetrable. The machines could be configured in 103 thousand million million million different ways, and the Germans changed the code daily.

Alan Turing and Gordon Welchman came up with the Bombe machine that cracked the Enigma code, based on a pre-war machine developed by Polish codebreakers. Turing’s is the name most associated with Bletchley Park, but he and his fellow boffins, from mathematicians and scientists to chess champions, are only part of the picture. Once the codebreaking techniques had been developed, Bletchley Park’s wartime ‘intelligence factory’ ran as a super-efficient production line, gathering, at its peak, some 4,000 messages a day, extracting intelligence and communicating it along the chain of command – all at a breakneck pace.

Bletchley Park
Bletchley Park hut exteriors. Credit: Bletchley Park Trust

D-Day at Bletchley Park

When Bletchley Park opened in 1939 there were just 150 staff, all crammed into the Mansion; by D-Day, at the height of its powers, Station X was a secret city of 9,000 people – 75 percent of whom were women – working in purpose-built ‘huts’: a 24-hour rolling operation. So efficient had the system become that on D-Day itself, German Enigma messages were being intercepted, decrypted and passed on to Allied Command in as little as two and a half hours.

Pat knew little of all this. “We knew about Station X, but we never asked them anything and they never asked us anything.” In 1943 Pat was moved to an important Y station at Abbot’s Cliff, midway between Dover and Folkestone, only 23 miles from Cap Gris-Nez in France. It was a pivotal moment of the war – the run-up to D-Day – when swiftly intercepting messages that were passing between German ships was, more
than ever, a matter of life and death.

From her clifftop perch Pat had a front-row view of the comings and goings in the Channel below, watching endless convoys of ships glide westwards. “We couldn’t make out what looked like tables upside-down could possibly be.” As she later learned, they were sections of Mulberry harbour – a portable contraption designed to rapidly offload cargo onto beaches during the Allied invasion.

The statue of Winston Churchill outside Westminster

Operation Fortitude

One morning on the clifftop, Pat saw a familiar face: Winston Churchill was approaching, flanked by army officers. He walked to the edge of the cliff, the nearest point to France, and gazed across. His appearance there, Pat believes, was part of Operation Fortitude, a plan to fool the Germans into thinking the invasion would be at the Pas de Calais, rather than at Normandy, 120 miles west. “They knew that the German spies would report back, ‘Churchill has been seen in the Dover area’”, explains Pat.

D-Day itself was a time of extreme anxiety: “A lot of Wrens had fiancés or husbands who were involved in the Landings,” remembers Pat. “When they first landed there was a sort of silence. It was a very tense time.”

D-Day wreckage on the Normandy Beaches

Bletchley Park D-Day exhibition

The D-Day exhibition in the former teleprinter building of Bletchley Park does an excellent job of recreating the high-stakes tension leading up to the invasion, and shows how intelligence produced at Bletchley directly influenced its successful outcome. The invading troops had been briefed to an astonishing degree about the lie of the land, from the height of fences to the location of landmines – all information provided by Station X.

It is said that Bletchley’s work shortened the war by two years. Visiting this remarkable place, so little changed, it’s easy to imagine it scurrying with wartime activity. You can still wander in and out of Bletchley’s famous huts, visit the Mansion where the longstanding alliance between the UK and US intelligence agencies was born, get up close to Enigma machines and read diaries and letters by veterans.

Bletchley Park
A computer on display at Bletchley Park

VE Day 1945

On 8 May 1945, as the country celebrated VE Day, Pat went to Buckingham Palace to cheer the royal family and Churchill. “It was terrific,” she says, “but because my father was a prisoner of war in the Far East it was really VJ Day that my family wanted.” To the family’s joy, he was released at the end of the war and returned home. Pat’s service in the Wrens meant she was entitled to a grant to go to university, and she went on to become a distinguished journalist.

VE Day
VE Day in London. Credit: Galt Museum & Archives

Perhaps the most intriguing aspect of Bletchley’s story is that its secrets were kept for so long. Much of the evidence of codebreaking activity was destroyed after the war, and information was classified until the 1970s. Pat had kept her secret from her family, though unbeknown to her, her sister Jean had also worked in top-secret intelligence, as a cipher officer in Egypt and Italy. Decades after the war, the truth finally came out. “I said, ‘By the way, what were you doing in the war, Jean?’ I had no idea and she didn’t know what I’d been doing. The Official Secrets Act is terribly fierce.”

Find out more about visiting Bletchley Park, here. 

Getting there

There are direct rail services from London Euston to Bletchley (40min). Bletchley Park is a few minutes’ walk from the station.

Read more from BRITAIN:

Winston Churchill remembered

Remembering D-Day

Royal portraits: Photos at the palace