Could you have been a Bletchley Park codebreaker?

Not everyone who worked at Britain’s wartime codebreaking centre was a genius on the level of mathematician Alan Turing, who invented the machine that cracked the Germans’ Enigma codes.

But the thousands of clever young men and women pulled into Bletchley Park — the top-secret country estate in Buckinghamshire — did often share one particularly striking attribute: they all had an unusual love of puzzles.

Many of the recruits weren’t intellectuals at all. They were men and women — from all walks of life — who could not only examine a problem from different angles, but also enjoyed solving it.

Not so different, in fact, from anyone today who gets a kick from Sudoku or crosswords.

During World War II, however, Britain’s fate depended on the codebreakers’ ability to decrypt Nazi messages. This burden of responsibility could cause terrible stress, even breakdowns, at the place some Bletchley townsfolk — none the wiser — thought was a lunatic asylum.

But here’s the extraordinary thing: when they came off duty, the codebreakers often relaxed by diving into yet more puzzles.

So, how did the Government recruit the right people? And if you had been around at the time, would someone be touching you on the shoulder and discreetly telling you to report to ‘Station X’ — the codename for Bletchley?

Today I’ll be giving you the sorts of brainteasers, problems and enigmas that were used either to recruit the codebreakers, or to provide a bit of escapism when they were off-duty.

You don’t need to be exceptionally gifted to solve them. But an interest in puzzles, and being able to think laterally, will give you a head start.

As for the directors of Bletchley, at first they were very conservative in their approach to recruitment. In 1938, they began by homing in on university mathematics departments. These students, it was felt, would be best qualified to take on the Enigma, the Germans’ electric cipher machine, which could, in theory, produce 159 million million million combinations of letters.

But breaking codes was an art as well as a science. And as the Government began erecting the wooden huts that would house Bletchley’s top-secret decryption activity, the recruiters became cannier.

They now started also looking for young people with exceptional language skills. Some of the recruits were young women from aristocratic families, who’d learned other languages at German and Swiss finishing schools in the Thirties.

Alan Turing, the best known codebreaker at Bletchley Park during the Second World War

Then the net was thrown wider still to scoop up thousands of women who were thinking of joining the Women’s Royal Naval Service, Women’s Auxiliary Air Force or Auxiliary Territorial Service.

Application forms asked: did the candidate enjoy solving puzzles? If the answer was yes, the women were then given several intelligence tests.

The brightest would be issued with a ticket for a train journey to a secret destination — after swearing never to reveal the details of the crucial codebreaking work that was about to consume them.

Along the way, other types of talented individuals were taken on. Poets, for example, had an affinity and ear for the infinite possibilities of language.

Another group were people who could reconstruct long-dead languages by breaking different sorts of code — such as the hieroglyphics used by pharaohs.

Last but not least were the chess champions. To excel at chess is to hold 100 abstract possibilities in one’s head while trying to out-think one’s opponent — so it followed that chess players made formidable codebreakers.

And so they all came flooding into Bletchley Park. For every socially awkward mathematician, there was a confident debutante; for every owlish classicist, conversing in ancient Greek, there was a swing-music-loving Wren who enjoyed doing fiendish crosswords.

And they all put their talents to the best possible use — by helping to shorten World War II by nearly two years.

Extracted from Bletchley Park Brainteasers by Sinclair McKay, published by Headline at £12.99 on October 19. To order a copy for £10.39 (valid until October 21), visit mailshop.co.uk/books or call 0844 571 0640. P&P is free on orders over £15.  

And here’s the 1942 crossword they had to solve in 12 minutes…

The story of using people with a talent for crosswords as codebreakers begins in 1941.

Back then, as the war in North Africa was unfolding, letter writers to The Daily Telegraph seemed concerned not so much with military gains as with the quality of the daily crossword. Among the readers’ letters were complaints that it had simply become too easy.

These caught the attention of W. A. J. Gavin of The Eccentric Club, a Mayfair dining society which catered for a membership of original thinkers. And Gavin thought it would be amusing to put up a prize for a special challenge.

So he contacted Telegraph editor Arthur Watson, who was taken with Gavin’s idea of offering a £100 prize for anyone who could solve the daily cryptic crossword in under 12 minutes.

A challenge was issued to Telegraph readers. Those who accepted were invited to the newsroom; and in January 1942, five people succeeded in filling in the puzzle in the allotted time. Though the prize money was a substantial sum, a greater prize lay behind it. Because also there were figures from a shadowy sub-department of MI6.

One of the winners, Stanley Sedgewick, recalled what happened next: ‘I received a letter marked “confidential” inviting me . . . to make an appointment to see Colonel Nicholls of the General Staff who would “like to see you on a matter of national importance”.’

Mr Sedgewick duly went along to Whitehall, signed the Official Secrets Act, and discovered that he’d just been recruited to the Bletchley Park operation. The other four winners were coaxed in a similar fashion.

Do you think you could manage to complete the famous crossword printed in The Daily Telegraph on January 13, 1942? Then why not have a go below? If you finish it within 12 minutes, congratulations! Sixty-five years ago, you would have been singled out by the War Office as one of the codebreaking elite. 

Now try the brainteasers that picked out the brightest… 

 Scroll down for the answers…