The Secret War: Spies, Codes and Guerrillas 1939–1945. Max Hastings

rather than as Alan. When his Enigma study was circulated later in 1940, it became known as ‘the Prof’s book’. He also set about fulfilling his concept for a ‘bombe’, a primitive but revolutionary electro-mechanical device for exploring multiple mathematical combinations. This borrowed its name, though not its design, from the Polish ‘bomby’, and would be capable of examining the 17,576 possible wheel deployments for a three-rotor Enigma in about twenty minutes: the order for the first machine was placed in October 1939, and the prototype became operational six months later. Meanwhile, outside in the park, workmen sawed and hammered at an ever-widening array of low wooden buildings which housed the growing staff. Eventually, only administrators worked in the main building, where the telephone switchboard was established in the ballroom. In the huts, signals were shifted from one section to another on a small trolley pushed along a makeshift wooden tunnel.

      Hut 8 attacked German naval traffic, which was then passed to Hut 4 for translation and processing. Hut 3 performed the same function for Wehrmacht and Luftwaffe traffic decrypted by Hut 6. The former would eventually play a pivotal role in Allied wartime intelligence, but in its early incarnation it had a staff of just four. Frank Lucas, who was one of them, wrote: ‘On a snowy January morning of 1940, in a small bleak wooden room with nothing but a table and three chairs, the first bundle of Enigma decodes appeared. [We] had no idea what they were about to disclose.’ A few score yards away, Hut 6 run by Gordon Welchman wrestled with army-Luftwaffe ‘Red’ key traffic, which was the first to be broken in bulk.

      From the outset, pains were taken to disguise from all but the most senior operational commanders the fact that information was being gained from codebreaking. This gave an unintended boost to the prestige of MI6, and to that of Stewart Menzies in particular. When Reg Jones gave a disguised report based on an Ultra decrypt to the RAF’s director of signals, Air Commodore Nutting, the airman professed astonished admiration for the courage of the presumed spies who had provided the information, saying, ‘By Jove, you’ve got some brave chaps working for you!’ The ever-growing scale of the enemy traffic to be trawled was intimidating. It is a measure of the expansion of communications as a branch of warfare that by August 1943, 305,000 personnel among the Luftwaffe’s total strength of 2.3 million were employed on signals duties – transmitting, receiving or processing – and the same was true on both sides of the war, and of all armed forces.

      At GC&CS there were inevitable personality clashes. Gordon Welchman, whose creative contribution became second only to that of Turing, and whose organisational skills were also priceless, found it hard to work with the highly-strung and fractious Dillwyn Knox, a contender for the hotly contested title of Bletchley’s star eccentric. A notoriously awful driver, Knox giggled: ‘It’s amazing how people smile, and apologise to you, when you knock them over.’ He sustained a stream of intemperate complaints and demands to Denniston, his old comrade from Room 40, about staff shortages, working conditions, low pay, together with the intrusion of and excessive authority conceded to non-cryptanalysts: service intelligence officers ‘who maul and conceal our results’. Knox was seriously ill with the cancer that would kill him in February 1943, but meanwhile he and Welchman bickered: the older man accused the younger of exceeding his narrow initial brief, and was also impatient of Turing, writing, ‘He is very difficult to anchor down. He is very clever but quite irresponsible and throws out a mass of suggestions of all degrees of merit. I have just, but only just, enough authority and ability to keep him and his ideas in some sort of order and discipline. But he is very nice about it all.’ Turing prompted mirth by joining Bletchley’s Home Guard because he was seized by an impulse to learn to shoot, then provoked the apoplectic rage of its colonel by absenting himself from parades once he had fulfilled this private purpose. His unworldliness could provoke real exasperation among those under relentless pressure to produce results. A colleague spoke of Turing’s ‘almost total inability to make himself understood’.

      There were plenty of minor tantrums lower down the hierarchy, unsurprising when staff were performing stressful tasks through long hours in bleak working conditions. Angus Wilson, the later novelist, once vented such a storm of rage that a colleague said wearily, ‘Do stop it, Angus, otherwise we’ll put you in the lake!’ Wilson retorted defiantly, ‘Don’t worry, I’ll do it myself,’ and duly plunged into the water in front of the house; on another such occasion he hurled a bottle of ink at a Wren. Many wartime codebreakers suffered temporary or permanent physical or mental collapses, brought on by their work: William Friedman, one of America’s pioneer practitioners, underwent a nervous breakdown in January 1941 which incapacitated him for three months. Hugh Trevor-Roper languished for several months at about the same time, and others regularly succumbed.

      German signals were at first intercepted by a battery of army wireless-operators stationed in an old naval fort at Chatham, a role later assumed by Gambier-Parry’s organisation at Whaddon Hall. In the early war years there were never enough operators, and both the RAF and the army were reluctant to acknowledge the priority of meeting GC&CS’s demands. Signals were brought in batches to Bletchley’s guardroom by motorcycle couriers, at all hours and often in dreadful weather, then distributed between the relevant huts. From an early stage, the codebreakers learned to identify German senders by the unencrypted preamble to their message texts, none of which was longer than 250 words. It was then a matter of sitting hunched over a deal table through the hours of a shift, pondering a jumble of numbers and letters from which only men – and Bletchley’s handful of women – with remarkable logical or mathematical powers might hope to extract fragments of meaning. ‘The ideal cryptanalyst,’ Stephen Budiansky has written, ‘was Beethoven with the soul of an accountant.’ When Christopher Morris was a new recruit to Bletchley he heard one of his senior colleagues, asked the requirements for the job, respond laconically, ‘Oh, I suppose a sharp pencil and a piece of squared paper.’ Morris himself thought that the main requisites – except at the exalted level of Knox, Turing, Welchman and later Max Newman – were ‘patience, accuracy, stamina, a reasonably clear head, some experience and an ability to work with others’.

      They opened what became vast card indexes, stacked in shoeboxes along the sides of the huts, cataloguing enemy units, personnel, codenames, locations, abbreviations and military hardware; different Enigma keys were distinguished by colour – for instance, yellow, green, red and blue, respectively indicating Norway, Wehrmacht, army-Luftwaffe and air training codes. ‘When a new word came up in the message you were translating,’ wrote Hugh Skillen, ‘a new type of jet fuel, or machine part – you looked for it, and if it was not there, the indexer put it in with a reference time and date stamp.’ Bletchley’s meticulous record-keeping became a critical element in its triumphs.

      For security reasons, the Park’s operations were rigidly compartmentalised, and there was little exchange of information or gossip between sections. Even Welchman remarked years later how little he knew about what colleagues were doing a few yards away from his own Hut. As the staff grew from hundreds into thousands, facilities lagged behind: a section head complained that two hundred men and women enjoyed the use of just one lavatory. The food in the Bletchley canteen was poor even by wartime standards. Former debutante Sarah Norton one night found a cooked cockroach in her meat: ‘I was about to return it to the catering manageress when my friend Osla, who had the appetite of a lioness with cubs, snatched the plate and said: “What a waste – I’ll eat it!”’ The nearest available delicacies outside the wire were to be found at the Station Inn in Bletchley town, which offered ox heart. Welchman recalled having to provide his own newspaper to wrap fish and chips at the local shop. The codebreakers worked around the clock in three rotating shifts, starting with 8 a.m. to 4 p.m. When the exhausted men and women cycled or took a bus through the blackout to their lodgings, they found few comforts: dim lighting, hot baths often rationed to one a week, draconian rules about inter-sex visiting.

      It is deeply impressive that those who worked at Bletchley sustained such dedication while working day after day, month after month, in a drab world devoid of glamour, excitement, variety, glory and decorations. In Hut 3, the watch sat around a horseshoe table, translating deciphered signals, each one resembling a telegraph flimsy, forwarded from Hut 6. Ideally, decrypts were composed of complete German