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

LAC Gray was also ex-aircrew, ‘grounded as result of crash’, had ‘B’ grade Spanish. Cpl Hodges, aged twenty-six, was unfit for aircrew, ‘anxious to use his German “A”, in civil life worked in architect’s office’. AC1 Tew, a twenty-eight-year-old clerk, had German ‘A’, as well as some Spanish, French and Danish, acquired while working in his father’s leather-trading business. There was much snapping between Bletchley and the Air Ministry about the latter’s reluctance to grant commissioned rank to RAF men seconded to cipher or wireless interception duties. Group-Captain Blandy of the Y Service complained that such people were ‘picked individuals having considerable linguistic qualifications and a high standard of education … [Mere Aircraftsmen] and NCOs lack the necessary authority required to carry out their duties efficiently.’

Not all the personnel posted to Bletchley proved suited to its demands. A March 1941 report on an RAF officer returned to general duties after a spell at BP noted: ‘Although an excellent linguist, he does not appear to me to have any aptitude or inclination for the research side of the work. He had been relegated to clerical tasks, but did not seem thus to justify his pay.’ There were equally bleak verdicts on the performance of some women staffers lower down the hierarchy: ‘Wren Kenwick is inaccurate, very slow and not a bit keen on her work, not very intelligent. Wrens Buchanan and Ford are unintelligent and slow and seem unable to learn. Wren Rogers suffers from mild claustrophobia and cannot work in a windowless room.’ The report concluded: ‘The remainder … are doing most excellent work,’ but the selectors were urged to recognise the importance of the jobs the women were required to fulfil, ‘and not to send us too many of the Cook and Messenger type’.

Enfolded within their oppressive security blanket, Bletchley’s people lived, loved and largely played within their own community. Almost all were paid a pittance: nineteen-year-old mathematician Mavis Lever, one of ‘Dilly’ Knox’s team, initially received thirty shillings a week, of which she paid twenty-one shillings for her lodgings. When staff did escape into the world beyond the perimeter fence, the civilian status of the young men incurred dark suspicions among the uninitiated about their absence from any battlefield. The dramas and pantomimes performed by the Park’s amateur dramatic society became high spots in the annual calendar: Frank Birch, formerly of King’s College, Cambridge and now head of Hut 4, was celebrated for his appearances as the Widow Twankey in productions of the pantomime Aladdin .

By 1942, common sense had achieved some important successes in the Park’s management. Each section worked to its appointed head, irrespective of rank or lack of it. Cryptanalysis for all Britain’s armed forces was handled entirely at Bletchley and its Indian out-stations, a concentration of effort that neither Germany nor the United States ever matched. Gordon Welchman emerged as the foremost lubricator, curbing feuding; several notoriously stupid service officers were transferred out; the popular Eric Jones was appointed to head Hut 3. It was acknowledged that the civilian codebreakers must be ridden on the lightest possible rein, though the director was prone to occasional surges of authoritarianism.

On 1 February 1942, Admiral Karl Dönitz introduced a reflector or fourth rotor into the Atlantic U-boat service’s Enigma, with immediate and calamitous results for Allied fortunes in the Battle of the Atlantic: this imposed a twenty-six-fold increase in the range of possible settings, and blinded Bletchley. Sinkings soared. At sea, the Royal Navy was obliged to rely upon ‘Huff-Duff’ to locate enemy submarines until these approached within range of underwater detection by the Asdics of convoy escorts, which were impotent against night surface attackers. Breaking what was now designated the ‘Shark’ submarine key became the Park’s foremost priority, a challenge unresolved for nine frightening months, by far the most stressful period of the war for those engaged in the task. They knew, as they sat hunched over their labours in those austere huts, that at sea men were dying every day because of their failure – though no rational person would have called it such.

Also on 1 February, coincidentally, Alastair Denniston was pushed aside into a subordinate London role, to be replaced by his deputy, Edward Travis. In some measure this development reflected a clash of personalities – Denniston and Stewart Menzies disliked each other – together with the infighting characteristic of any large bureaucracy. But it was widely felt at Bletchley that its operational head was being overwhelmed by the strains of running an establishment that since the outbreak of war had increased fourfold in size, and many times that much in its importance to the war effort. Power struggles were unavoidable. Denniston was a good and kind man who had done many things well, but Bletchley had outgrown him. Travis, whose edicts were issued in a curious trademark brown ink, was generally considered a success in his new role, not least by such influential creative figures as Welchman. When another codebreaker, Ralph Bennett, returned that summer from detached duty in the Middle East, he found that the atmosphere had changed markedly: ‘I had left as one of a group of enthusiastic amateurs. I returned to a professional organisation with standards and an acknowledged reputation to maintain. Success was no longer an occasional prize, but the natural reward of relentless attention to detail.’

Throughout 1942, Bletchley’s activities were hampered by a desperate shortage of bombes, and thus by argument about their best employment. In January the army-Luftwaffe Hut 6 was receiving 1,400 intercepts a day, of which an average of 580 were broken, a proportion that slowly increased, reaching about 50 per cent by May 1943. Often no more than one three-wheel bombe was available at any given time to work on the Shark U-boat cipher, because the others of what was still only a handful of machines were committed to breaking army and air traffic. The codebreakers said later that they would have needed ten four-wheel bombes – which did not then exist – significantly to accelerate their progress. By November, a note of desperation had entered the Admiralty’s pleas to the Park about Shark. The Battle of the Atlantic, said the navy’s Operational Intelligence Centre, was ‘the one campaign which BP are not at present influencing to any marked extent – and it is the only one in which the war can be lost unless BP do help’. A critical breakthrough was imminent, however. On 30 October in the Eastern Mediterranean U-559 was attacked by an escort group, and forced to the surface by depth-charging. Tony Fasson, thirty-year-old first lieutenant of the destroyer Petard , along with Able Seaman Colin Grazier, hastily stripped naked and swam sixty yards to the stricken submarine, then hauled themselves into the conning tower. The crew had opened the seacocks before abandoning their boat, and the sea was flooding in even as the two men searched the control room with desperate urgency.

They found treasure: the second edition of the Wetterkurzschlüssel , or weather short signal book, for its Enigma. Having wrapped this and other documents in waterproofing, Fasson and Grazier handed them up the hatch to sixteen-year-old NAAFI canteen assistant Tommy Brown, who had followed in swimming to the U-boat. He in turn passed the packages to the crew of a whaleboat, which arrived alongside in the nick of time. Brown, a civilian, lived to receive a George Medal for his daring, but the two supremely dedicated British sailors pushed their luck by plunging once more into the submarine’s control room, possibly in the belief that that they might retrieve a cipher machine. Bletchley did not need this, for it had already reconstructed the wiring of a four-rotor Enigma: it was the signal books that mattered. U-559 suddenly vanished into the Mediterranean, taking with it Fasson and Grazier, both of whom received posthumous George Crosses. The captured documents reached Bletchley on 24 November, and made possible the critical break into the Shark key on 13 December, assisted by data from weather decrypts secured by Hut 10.