The Secret Lives of Codebreakers

by Sinclair McKay

  Similarly, most of the young people who worked at Bletchley would only ever have read about the aristocracy. Certainly they would have been highly unlikely in any other circumstances to meet such rarefied creatures, while the smart “gels” who volunteered their services would have had only the patchiest idea about the lives of those alongside whom they were now working.

  But Bletchley represented the last gasp of the notion of the smarter set and their sense of mucking in and doing what one could, just as it represented in miniature the oncoming triumph of the middle classes: the classes for whom the old snobberies were being cast aside, not merely in the interests of the nation pulling together, but because they had read Orwell and Priestley and understood the terrible privations suffered by so many in the 1930s, and were determined that a better country should come of this.

  When Captain Eric Jones was put in charge of Hut 3, everyone who worked with him could not help remarking on his Cheshire vowels and indeed the source of his wealth (“… His qualifications for the post were not immediately apparent. He was a wholesale cloth merchant from Macclesfield,” wrote William Millward. Peter Calvocoressi thought that he had been “something in biscuits”)—but, crucially, these same people stressed how brilliant he was in the role. All who worked with Captain Jones (later to become Sir Eric) were full of praise for his strong principles and the strength of character that enabled him to deal smoothly with “tiresome intrigues and controversies,” as Millward put it.

  The point they seemed to be making—only slightly patronizingly—was that Jones’s background was an indicator of quiet strength, and that he was the reverse of a chinless wonder. And in contrast to the pre-war Foreign Office days, when recruits tended to be plucked from the more privileged classes, Jones was one of the men who was to form the post-war establishment, going on to head the successor to Bletchley Park, the Government Communications Headquarters (GCHQ).

  Even if they could not have known it, these young cryptographers, from the minor public schools and the grammar schools, and their peers, were set to become the dominating voices of the new age. And by 1941, the nature of the conflict was changing, intensifying further; for Bletchley, it would prove a crucial year in which Britain’s fortunes were ever more vulnerable. For all those who worked at the Park, it was a time of both exhaustion and occasionally elation.

  13 1941: The Battle of the Atlantic

  As the war widened and unfolded, the importance of Bletchley Park’s work—and the concomitant pressure to get every tiny detail absolutely right—increased accordingly. In 1941, during the Battle of the Atlantic, German spies in various ports reported back to German High Command that a vast British convoy, comprising thirteen cargo boats, four tankers, and ships carrying innumerable aircraft parts, was sailing off the coast of Africa. This message to Hitler was sent by radio—meaning that it was also picked up by British Signals Intelligence. It was decoded at Bletchley perhaps even before German High Command got to read it. As a result, the British convoy was alerted to the imminent German danger and was able to take evasive action.

  The nightmare dangers that the Atlantic convoys faced were all too easy for those back home to imagine; the vessel ruthlessly stalked by U-boats, torpedoed, with countless crew and sometimes civilian passengers perishing in the dagger-cold ocean waters. Anxiety over the peril to supplies was matched by the ache of sympathy for the men out on those seas. So a naval victory of any sort always proved to be an effective morale booster back in Britain.

  There was an important lifting of spirits at sea in March 1941 thanks in great part to Mavis Batey, who had been working with Dilly Knox in the Cottage on the Italian Enigma. Mrs. Batey recalls with a smile how Knox was brilliant at getting people to look at problems from unexpected angles. “Dilly would ask: ‘Which way do the hands on a clock go round?’ One might say clockwise. But Knox would reply that that would depend on whether one was the observer, or the clock.”

  And this lateral approach was applied to Enigma. Mrs. Batey still has the “rods” that were used to work out the order of the wheels inside the machine, and the starting position of those wheels for the message being cracked. But the rods were not much use unless the person employing them had a lively intelligence; and it was deep into one September night in 1940 that Mrs. Batey had first found her way into the code, by guessing that the first word of a particular message, for which they thought they had the letters PERX, was in fact PERSONALE—“personal.”

  That gave her a start, yielding up two or three more potential letters within the message. A night’s worth of infinitely patient and extraordinarily focused work later, and Mrs. Batey had identified the wheel order and the message setting. It was a brilliant feat of inspiration and perseverance.

  Now, in the spring of 1941, it was this same light-touch but inspired approach that cracked a message to an Italian naval commander: “Today 25 March is X–3.” As Mrs. Batey says now, “If you get a message saying ‘today minus three’, then you know that something pretty big is afoot.”

  It was. Subsequent, more specific messages came in. Mavis worked through shift after shift, not leaving the Cottage. And then: “It was eleven o’clock at night, and it was pouring with rain when I rushed, ran, absolutely tore down to take it to Intelligence, to get it across to Admiral Cunningham.”

  After some work, intelligence analysts deduced from the message that the Italian fleet was planning to attack British troop convoys sailing from Alexandria to Piraeus in Greece. Admiral Cunningham was in charge of the operation that explosively ambushed four Italian destroyers and four cruisers off the coast of Sicily. From the point of view of the Italians, the British had sailed up out of nowhere.

  It was a spectacular coup, as Admiral John Godfrey, Director of Naval Intelligence, was keen to tell Bletchley Park. He rang with a message: “Tell Dilly that we have won a great victory in the Mediterranean and it is entirely due to him and his girls.”

  Mrs. Batey illustrates vividly how, when something of vital importance was going on, the codebreakers would not budge until their job was done. “Finally,” she says, “the work was finished in the middle of the night after three nights.”

  Mrs. Batey is modest about her pivotal role. “It was the Italians’ errors that gave the game away,” she says. “Our eyes were so used to picking things out. I got a long message and it didn’t have a single ‘L’ in it. The Italians only ever sent out a few telegrams, so the very idea that they were sending messages out automatically gave you the signal that they were going to do something for a change.

  “And so they sent out dummy messages all the time so it would look like a uniform transmission. And of course, what this Italian chap had done was just to sit with his finger on ‘L,’ smoking a cigarette, the biggest crib there ever was.

  “A message that long that contained only ‘L’s! That actually broke one of the wheels of the Italian Enigma machine.”

  Another 1941 sea battle of some significance to Bletchley took place inside the Arctic Circle, and featured a British attack on German ships. The real target was a trawler called Krebs; for it was known that on board this vessel was an Enigma machine, which could prove invaluable for breaking into those almost impossible German naval codes. The German captain, sensing the danger, threw the Enigma machine overboard into the freezing ocean, but he was killed before he had a chance to destroy his coding documents and bigram tables. The vital documents and tables were retrieved, eventually taken back to Bletchley and pieced together.

  Then, even more brilliantly, came the episode of the U-110. This was the U-boat that had, in the first few days of the war, caused widespread public horror by torpedoing and sinking the passenger ship Athenia. Now the U-110 was itself depth-charged and captured in the Atlantic. The captain, Julius Lemp, was unable to prevent the British from seizing vital Enigma material, including bigram tables. These in turn were rushed back to Bletchley. The submarine was being towed to Iceland when it sank; the crew who had torpedoed and drowned s
o many sailors were now themselves lost. But it was from these courageous naval operations that grew Bletchley’s outstanding achievement—the breaking of the notoriously unbreakable naval Enigma.

  Even back in 1940, Alistair Denniston had remarked to Head of Naval Section Frank Birch: “You know, the Germans don’t mean you to read their stuff, and I don’t suppose you ever will.” However, from these tables, and other data, Alan Turing calculated a new method into the codes, which became termed “Banburismus”—in essence, as his Hut 8 colleague and sometime fiancée Joan Murray recalled, it involved “punched holes on long sheets of paper, made at Banbury.”

  Often on the night shifts, recalled Joan Murray, “around midnight was a particularly interesting time, since the German Naval keys changed at midnight, but results of analysis of most of a day’s traffic began to reach us before then.”1 The result, she recalled, was that very often people were too absorbed at the end of the shift—like Mavis Lever—to even think of going home. Instead, they preferred to stay on and carry on working with the following shift.

  And the effect it began to have on the course of the war was almost incalculable. In the first few months of 1941, U-boat attacks on the convoys had meant that Britain was facing a catastrophic shortfall of imported food; if the submarines could not be thwarted, there would literally not be enough to feed the population. On top of this, there would not be enough imported oil for war production to continue. Now, according to Jack Copeland, convoy re-routings “based on Hut 8 decrypts were so successful that for the first twenty-three days [of June], the north Atlantic U-boats made not a single sighting of a convoy.”2

  In the midst of these events, Joan Murray gave a short description of Alan Turing, and his own gentle abstraction. “I can remember Alan Turing coming in as usual for a day’s leave,” she wrote, “doing his own mathematical research at night, in the warmth and light of the office, without interrupting the routine of daytime sleep.” Another veteran recalls Turing’s abstraction when being congratulated for his work by a senior ranking officer, while later, Hugh Alexander was to say of Turing’s role that “Turing thought it [naval Enigma] could be broken because it would be so interesting to break it.… Turing first got interested in the problem for the typical reason that ‘no one else was doing anything about it and I could have it to myself.’ “3

  No better example then of the partnership between unfettered mathematical inquiry and the national interest. For much of that summer, Bletchley was able to read the majority of German naval Enigma messages, and in so doing could provide protection beyond value to British shipping. In the days before either America or Russia had joined the conflict, and when Britain was standing quite alone, this feat could easily be counted as one of the decisive points in the war.

  There were other examples in 1941 of just how vital the work at Bletchley was. It was entirely thanks to the decoders that the British were forewarned of the German intention to target not Malta—despite the false impression the Germans were trying to give—but Crete. In spite of this advance warning, Crete was to fall, but the warning did perhaps help with the evacuation of some 17,000 troops. Elsewhere, similarly, amid the generally dispiriting progress of the war in Africa, an Enigma decrypt concerning the size and formation of Rommel’s forces at the Halfaya Pass on the Egyptian border offered at least the consolation prize of enabling the British forces to escape being crushed.

  There was also the fantastic coup of the Bismarck. In May 1941, this mighty and formidable battleship, commanded by Admiral Lutjens, had sunk the British vessel HMS Hood. Out of the crew of 2,500 men, only three survived. A few days later the Royal Navy had, with the help of Bletchley, tracked the position of the Bismarck. In an effort to conceal the fact that the signals had been intercepted, it was arranged for the air force to fly two or three reconnaissance planes over the area, to give the Bismarck’s crew the impression that this was how they had been spotted.

  In fact, the Bletchley Park intercepts had been the result of a certain amount of serendipity. Jane Fawcett, MBE, was there as the scenario unfolded. She recalls:

  “I was in Hut 6 and on the occasion of the Bismarck codes, I worked a 24-hour shift all the way through. We intercepted a message from one of the senior military commanders in Berlin—he was asking German High Command for the whereabouts of the Bismarck because his son was on board. His message went: ‘Where is my son?’ And the message back told him. The Bismarck was at Brest.” Interestingly, in 1974, the late Diana Plowman made an inscription for the benefit of her family in her copy of Frederick Winterbotham’s book. In this inscription, she gave a miniature portrait of life at the Park. And at the very end—again, solely for the benefit of her relatives—she wrote: “But the Bismarck was my own special piece of luck.”

  After the message was intercepted, a ring of British warships attacked the Bismarck. In all, 2,300 of its crew drowned. The mighty symbol of the strength of the German navy was scuttled. The effect in Germany was serious. One senior Reich figure observed: “The Führer is melancholy beyond words.”

  The activity prior to this great triumph had been similarly intense in Hut 4. One veteran recalls cots, or small camp beds, being moved in so that the personnel concerned would never be far from developments. One codebreaker, Walter Ettinghausen, spent forty-eight hours in the hut; he eventually emerged, “unkempt and unshaven,” and announced to his colleagues that “the Bismarck had finally been chased down.”

  Perhaps appropriately, given the centrality of the conflict at sea, there was now a distinctly naval flavor to the personnel at Bletchley Park. This chiefly took the form of the Women’s Royal Navy volunteers, the first of whom were just starting to arrive. Ruth Bourne was such a young woman, although pleasingly, she was a little less impressed with the central notion of Bletchley than her commanding officers seemed to be.

  “When we were called up, we had to go to training camp,” she says. “And even though I lived and volunteered in Birmingham, we were sent all the way up to a castle called Balloch, outside of Glasgow. And there was what had been a farm called Tallyhewen and this farm was turned into a Wrens’ training camp.

  “And that’s where we spent the first three weeks doing naval training—salutes, square bashing, cleaning out the ablutions. Organizing concert parties, whatever you wanted to do in your leisure. Then at the end of that period, there was a mustering process and people were told what they were going to do.

  “A group of us were told we were going to do SDX—and that was connected to joining a ‘ship’ called HMS Pembroke 5, which was later on shortened to P5. Anyone who was P5 was doing bombe operating and codebreaking and so on. But we didn’t know that then.

  “Eventually when we were brought in to see the Petty Officer, we were told that this was highly secret work—if we entered into it, we would not be able to leave it.”

  There was that one tiny opportunity to back out if the idea seemed utterly uncongenial. “At that stage, we could have opted out, but no one ever did,” says Ruth. “And then when we’d been told that, we were taken somewhere else and asked to sign the Official Secrets Act and then we were taken into what was known as B-Block, which was a huge block eventually where we finished up. My strongest memory is of the Chief Petty Officer saying ‘We are breaking German codes’ with a kind of triumphant smile.”

  As Diane Payne recalled in an essay, it was often difficult to explain to loved ones exactly why one wasn’t on board a ship, as one had signed up to be:

  My pay amounted to thirty shillings a week as an ordinary Wren, rising to £4 10s when I later became a Petty Officer. We had no category badges, and were supposed to say, if asked, that we were just “writers.” Sometimes it was very difficult having so little to say about one’s life, and this explanation did not always satisfy relatives and friends, so my wartime activities were considered unimportant and something of a failure.

  By now, the numbers working at the Park were expanding as the decrypting grew steadily more successful
and reliable. As historian and codebreaker Asa Briggs succinctly put it: “I’d never seen so many women in my life!”4 Often, when looking out from her office on the first floor of the house, over the lawn and the lake, recalls Mimi Gallilee, one could see, at shift changeover time, “a great sea of bodies. All these people going to and from the coaches that would ferry them to their billets in the outlying villages. Countless people, all milling about—it was a magnificent sight.”

  Around this time, Bletchley was using so-called “Hollerith Machines,” mighty efforts that processed punch cards, another logic-based means into some of the codes. And it was obvious that it would be better to have these machines operated by people who knew how they worked. One such group was very loosely termed “the Lewis Ladies.”

  The Park authorities had, in their search for Hollerith personnel, turned to the retail firm John Lewis; it used similar punch-card machines, and had women specially trained to use them. Making a plea via the Ministry for Labour and National Service, the Park interviewed fifty of these young women and selected ten. To the fury of the Park authorities, the Ministry suddenly withdrew the offer and allocated the John Lewis women to land work instead. Vinegary memos passed back and forth. One read: “The John Lewis episode is a disgrace.”

  The fight between Bletchley Park and the monolithic bureaucracy grew so rancorous that eventually Churchill got to hear of it. As recorded in one Park memo, “the shortage of personnel reached the ears of the PM who directed Ismay to render an immediate report on the shortage of female personnel.”

  It was a significant problem, as another memo from September 1941 makes clear: “We have had some very considerable difficulty in recruitment, especially women clerks, and we are now considerably underborne with the result that some very important jobs are being held up.”