Margaret went to Courns Wood to work alongside Dilly while Mavis took charge of the Cottage, aged just twenty and on the basic £150-a-year salary of a female linguist. On 8 December 1941 she broke into a message on the link between Belgrade and Berlin, allowing the reconstruction of one of the rotors. Mavis was elated by her success, which proved that the Italian naval Enigma breaks hadn’t simply been lucky – although she would say that luck was always the key.
‘Dilly and I were never worried about probability; it was serendipity that counted and it seemed to me that there was a good chance of finding lobsters and sometimes it worked and sometimes it didn’t, and this time it did.’
Commander Denniston wrote to Stewart Menzies, the head of MI6, to let him know of the success: ‘Knox has again justified his reputation as our most original investigator of Enigma problems. He read one message on December 8th. He attributes the success to two young girl members of his staff Miss Rock and Miss Lever, and he gives them all the credit. He is of course the leader, but no doubt has selected and trained his staff to assist him in his somewhat unusual methods.’
From that point on, Bletchley was reading all the high-level messages between the German intelligence officers running the double agents and Berlin, and the Double Cross Committee knew with absolute certainty that the Germans believed all of the false intelligence they were being fed.
Two months later, Mavis broke a second Abwehr machine, the GGG, which was used between the German intelligence officers in Spain, where most of the agent runners were based. Little wonder that when questioned by the Hut 6 mathematicians over his use of ‘Dilly’s Girls’ and how effective they were, Dilly invoked one of the most famous discoveries of the ancient Greek mathematician Archimedes:
‘Give me a Rock and a Lever and I can move the universe.’
The new material was codenamed ISK, standing for Illicit Signals Knox, and a new section was set up to decode it. Dilly might have been largely housebound by the cancer, but it didn’t stop him looking for the additional girls he needed to work in his new ISK Section.
Jean Orme lived in Wendover, ten miles north of Dilly’s home at Courns Wood and on his route into Bletchley Park, so when her name was put forward by one of his other girls, he stopped off to interview her himself. Jean’s father was the village doctor.
‘I didn’t get off to the best of starts because I had a terrible cold so I was still in bed when he arrived. It must have been quite early. He asked me if I knew any German. He said it might be useful to know a few words. He was clearly not a well man. He spent most of the time telling me about the people who worked in the Cottage, including one woman who he said was really nice but who wore trousers and a bow tie, and smoked a pipe.’
At any event, after going back to school to learn some basic German, Jean was put to work in the ISK Section. She hadn’t done brilliantly on her School Certificate and didn’t expect to go to university, so it was something of a surprise to her that Dilly thought her suitable for the work.
‘I was seventeen. I was shy and a bit naive. I had tried to join the Wrens but I wasn’t actually old enough. I suppose someone must have shown me what to do. It was a bit like a crossword puzzle. One became quite good at it. I found it was something I could do. There was an awful lot of luck and chance, but I enjoyed doing it, that’s half the battle.’
Jean’s mother, who was a senior member of the British Legion, used her contacts to arrange a safe billet for her daughter with a Baptist minister and his wife in Stony Stratford, even though Jean’s family were all devout Roman Catholics.
‘They were very kind. I think it must have been a thankless task: they were paid twenty-one shillings a week and we worked strange hours. After about eighteen months, I got more independent and decided to move into the women’s hostel just outside the gate initially, but I could only stay there for about six months. I was then given a billet in Buckingham with a young woman whose husband was in the army in Italy. She had a seven-year-old daughter. She was very kind.’
In her spare time, Jean played tennis on the courts beside the Cottage, went to the beer hut with her friends and to the dances held once a month in the main assembly hall; this was just outside the gates, so people who didn’t work at the Park could be invited.
‘There was a certain camaraderie about it all. There weren’t many there, but the section did grow quite considerably. We must have had up to twenty people on each shift.’
The ISK Section was expanding and was now too big for the Cottage so it was moved into Elmer’s School alongside the section dealing with the more basic German secret service codes. A number of WAAFs were added to the section to operate modified Typex machines designed to simulate the Abwehr Enigma. They set them up to the keys worked out by Jean and the other girls and typed out the German message on strips of sticky tape, just like the Hut 6 Decoding Room.
‘When we thought we had the right answer the girls would set up the machines and hopefully if we’d done our job properly they would get the answers coming up. It was then sent to the translators next door. I don’t think I ever knew any more than that. The security in the Park was absolutely unbelievably tight.’
Dilly spent most of his time at Courns Wood, working with Margaret on a top-secret project which not even Mavis knew anything about, but he did come in occasionally to see them, and once when Jean was going to see her parents for some leave, he offered to drop her off on his way home.
‘I had one hair-raising journey with him when he volunteered to drop me off at Wendover. He drove half the time with no hands on the wheel because he was explaining various things. Fortunately, Mrs Dilly was in the car. In the end she said, “Dilly, you really ought to put one hand on the steering wheel.”’
Margaret was seriously ill herself for several months in the first half of 1942 and Peter Twinn and Keith Batey were brought in from Hut 8 and Hut 6 to bolster the codebreaking capability in the ISK Section. While Keith had deliberately ignored Mavis’s attempt to draw him into picking up her pencil when they were working on the Italian naval Enigma, romance blossomed once they were working together full-time.
But, like many of the young men at Bletchley, Keith felt that he should be taking a more active part in the war. There was undoubtedly pressure on the young men. They had friends who were on the front line, who had no idea why Keith and their like had safe jobs in the countryside, away from the fighting and the bombing. The woman who provided Keith’s first billet had even demanded an assurance that he wasn’t a conscientious objector before she was prepared to let him into her house.
Keith told Gordon Welchman bluntly that there was no reason not to let the young men who wanted to do their bit go off to war. Women were perfectly capable of breaking codes. Mavis, Margaret and Joan Clarke had all shown that, and many of Dilly’s Girls were doing the routine work without any idea of mathematical theory or how the code worked, most of them without ever having seen an Enigma machine. Why not allow the women to get on with it and let the fit young men play their part in the war?
His bosses at Bletchley blanched at the idea of one of their leading Enigma codebreakers putting himself at risk of being captured and giving away the Enigma secret, but there was a compromise when Keith agreed to join the Fleet Air Arm, the Royal Navy’s air service, rather than the RAF; if he was shot down it would always be over the sea, with an expectation that he would die. Perhaps understandably, Mavis never found this particularly reassuring.
Meanwhile, Dilly’s condition was deteriorating. It was clear that he was living on borrowed time and in between his visits to the ISK Section, Mavis occasionally went over to Courns Wood in an official car to seek his advice on what they were doing. On one occasion, she spent the weekend there.
‘My most enduring memory of Dilly is staying at Courns Wood in his last spring. He had invited me over to see the “loveliest of trees, the cherry” now in full bloom under the guest bedroom. He was still passionate about trees but he could no longer do the
strenuous planting he so loved to do. I just helped him shake pine cone seeds into tobacco tins for scattering.’
Keith joined the Fleet Air Arm in June 1942, but he wasn’t taking any chances and before he left he proposed to Mavis, who agreed to marry him and had to confess to Dilly that she was engaged to a mathematician.
‘Although Dilly congratulated me heartily, he asked me if I knew that mathematicians as a breed were not very imaginative. I reassured him that this one was all right. When I showed Olive my engagement ring and said I had chosen it myself, she told me that Dilly had bought hers himself, as he thought that was what the bridegroom was supposed to do. By the tone in her voice, I rather detected that she too would have preferred to be in on the choice.’
Keith’s initial training didn’t go well. On his first solo flight, he came in to land so low that the examiners had to dive to the ground to avoid being decapitated. They passed him, largely because they were desperate for new pilots, but they expressed some reservations. He had to go to Canada to do his full flying training in November 1942 so Mavis and he got married at Marylebone Registry Office, with Peter Twinn as Keith’s best man.
‘Dilly sent us a lovely wedding present and said that if the Muse hadn’t left him he would have composed my wedding hymn.’
Dilly’s wedding present was a silver condiment set engraved with the letters ISK. There was a brief three-day honeymoon in the Lake District, which was interrupted by Keith’s brother Herbert, who came down from Carlisle to see them. Mavis was not at all happy when Keith spent most of one of their precious three days together playing chess with his brother.
After the honeymoon, Keith sailed for Canada. The U-boats were concentrating on sinking ships sailing along the east coast of America but Hut 8 at this time still hadn’t broken the Shark Enigma, so Mavis relied on the girls in the Naval Section to keep her informed of his ship’s progress across the Atlantic and safe arrival in Newfoundland.
‘Shortly afterwards, Dilly was admitted to University College Hospital and when I visited him his brother Evoe, who was editor of Punch, was by his bedside and they were roaring with laughter composing Dilly’s last words.’
Dilly went home to Courns Wood to die. He got out of bed when a representative of the King came to appoint him as a Companion of the Order of St Michael and St George, the traditional award given to members of the intelligence services whose work is so secret it can barely be acknowledged. Dilly was adamant that it was for Mavis and his ‘girls’ as much as for him.
‘Dilly insisted on getting dressed to receive the emissary from Buckingham Palace and typically he sent the decoration to ISK with a touching note saying it was really meant for us. It was heartening to know that he regarded ISK and what he called the “Cottage tradition” as the fulfilment of his career.’
Dilly died at Courns Wood on 27 February 1943, aged fifty-eight, and was buried in the woodland he had lovingly nurtured.
The breaking of the Abwehr Enigma codes and the messages that continued to pour out of the ISK Section provided the intelligence officers running the Double Cross operation with complete confidence that they controlled all the Nazi agents sent to Britain, and that all the false intelligence they were feeding back to the Germans was believed.
This allowed them to take the operation one stage further in the run-up to D-Day, supplying coordinated intelligence from all the double agents to create a completely false picture of a fictitious First United States Army Group, based in southeast England, which was to lead the main thrust of the Allied invasion against the area around Calais. The aim was to persuade the Germans to keep most of their troops near to Calais and give the real landings in Normandy an easier run.
The false intelligence was supplied to the Germans as individual pieces of information from a number of different double agents, which the Abwehr would be able to put together themselves with each agent seeming to back up what the others said.
The most important of the Double Cross agents used in this ‘deception operation’ was a Spaniard called Juan Pujol García, codenamed Garbo. He claimed in his reports to the Germans to be running a network of twenty-seven agents across the UK, including a Swiss businessman in Bootle who reported ‘drunken orgies and slack morals in amusement centres’ in Liverpool, and a Venezuelan in Glasgow who claimed Clydeside dockers would ‘do anything for a litre of wine’. When the Swiss businessman died of cancer, his widow took his place. The Venezuelan also ran agents in Scotland, one of them a communist who thought he was spying for Moscow. Garbo’s mistress, a secretary in the War Cabinet, slept with army officers to gather valuable pillow talk. All of these people, including the mistress, were complete fantasy – none of his agents actually existed. Indeed, his claims were so incredible that it would have been impossible to imagine the Germans believing anything he said if it were not for the ISK Section’s ability to read the messages encoded on the Abwehr Enigmas.
In the early hours of D-Day, 6 June 1944, as Allied troops poured across the English Channel, Garbo tried repeatedly to warn Berlin that they were on their way to Normandy. It was deliberately too late for the Germans to do anything about it, but ensured they still saw Garbo as their most reliable spy.
Three days later, with Allied forces struggling to break through the German defences, and two German armoured divisions on their way to Normandy, Garbo sent his most important message. His agents were reporting troops massed in ports in East Anglia and Kent. The Normandy landings were a diversion. The real landings were to be in Calais as the Germans had always believed. Garbo’s warning went straight to Hitler, who ordered the two armoured divisions back to Calais to defend against what he expected to be the main invasion thrust. This decision ensured the success of the Allied invasion. Had the two divisions continued to Normandy, the Allies might well have been thrown back into the sea.
Brigadier Bill Williams, the officer in charge of intelligence for the British troops at D-Day, said the deception would not have been possible had Dilly and his girls not broken the ‘Spy Enigma’. By the time the troops began wading ashore in Normandy, Dilly had been dead for more than fifteen months, but he had played a vital part in the success of the D-Day landings. By trusting Mavis, Margaret and the rest of Dilly’s Girls to follow his instructions and break the codes, he had achieved what was quite possibly the most important codebreaking success of the Second World War.
8
The World’s First Electronic Computer
The two-year period leading up to D-Day saw a huge increase in the number of people working at Bletchley and the Bombe outstations, and with every available young man needed for the fighting, the vast majority of the new recruits were women. In June 1942, there were 1,900 people working at Bletchley Park of whom two-thirds were female. By D-Day, 6 June 1944, there were just under 8,000 people at Bletchley with three-quarters of them women.
Even in the sections dealing with the Enigma codes, the number of women rose dramatically. By June 1944, there were more than 500 people in Hut 6 breaking the German army and air force Enigma codes and 460 reporting the intelligence in Hut 3. Hut 8 was substantially smaller, with 150 people, in part because the Americans were now doing a lot of the work on the German naval Enigma, but Hut 4, the Naval Section, had 950 people, of whom fewer than a hundred were men.
For security reasons the sections working on Enigma continued to use their original titles, even though they were now in the new brick- and concrete-built blocks. People had become comfortable in the old wooden huts and were not necessarily happy to move. Sally Norton complained of transferring ‘from Hut 4, which we loved, into a horrible concrete building’. Mair Thomas had similar feelings.
‘In all truth our new block was a bit of a dump. Even though it was brand new and built for the new workers it was grim and functional. It felt a bit like working in a factory or a battery farm. I didn’t like the inconvenience of moving; it was disorientating. The old hut, with all its shabbiness, was familiar and settled.’
; The facilities for women also increased. A local hairdresser set up a salon in the Park charging a shilling (5p) for a trim and three shillings and sixpence (17½p) for a shampoo and set. With too many of the billets having limited washing facilities, a bath house was built beside Block F and, amid concern that the lack of natural light in the new blocks was taking its toll on the health of some of the young women, a ‘Sun Ray Clinic’ was set up.
Commander Denniston had successfully established the idea that Bletchley should have first call on mathematicians, and to a certain extent linguists, in the early years of the war, but with far more fighting going on around the world there was now an increasing need for men on the front line and good reason why German and Japanese linguists were needed in other parts of the war effort. Women had to make up the bulk of the staff and even the four sections breaking the Enigma messages and reporting on them to London and to front line commanders were increasingly involving women in work that during the early years of the war had been the exclusive preserve of the men.
Hut 3 got around the Civil Service regulations on women working alongside men on the night shift by setting up an entirely female reporting shift for the Watch, who carried out all of the immediate intelligence reporting. Both Hut 3 and Hut 6 brought in large numbers of army intelligence analysts, the majority of them women, and Hut 6 split the main codebreaking section, the Machine Room, into two. The Hut 6 codebreakers who did the initial work looking for ways into the Enigma codes formed a new section, which like its Hut 3 equivalent was called the Watch. The Machine Room was turned into a completely female section, giving some of the women from the old Decoding Room and a number of smaller sections of Hut 6 some of the codebreaking work. The women taken out of the Decoding Room were largely replaced by female Typex operators who typed the messages out mechanically and had no need to understand German.
The men on the Watch worked out the cribs and passed them through a hatch into the Machine Room where a female codebreaker worked out the menus for the Bombes, liaised with the Wrens running the Bombes, and tested out the settings thrown up by them on captured Enigma machines.
The Debs of Bletchley Park and Other Stories Page 16