The Lost World of Bletchley Park Page 10
The 1943 Battle of Kursk in Russia was WWII’s largest tank engagement; the Russians received some crucial intelligence about German armaments from Bletchley beforehand, which helped swing the battle for them.
Churchill said that the Battle of the Atlantic and the threat of the U-boats caused him the greatest anxiety; it was also the cause of terrific pressure at Bletchley as codebreakers sought to crack the German Naval codes. Here convoy PQ18 is attacked en route to aid Soviet shipping in 1942.
Then there was the constant tension of the Battle of the Atlantic; months and years in which the Germans sought to strangle the lifelines of an island nation. It was those in Hut 8 who were dealing with the challenge of Naval Enigma, and the reason this hut more than any other caused so much anxiety and bitter fighting in Whitehall was that so much depended on it not failing. This is why the authorities looked so askance at Alan Turing and his young team; the survival of the nation appeared to be in the hands of abstruse, abstract disorganised mathematicians who could not even explain themselves in plain English. Were they really capable of breaking those Naval Enigma codes? Without being able to pinpoint positions and routes, there was very little that Allied shipping could do against the threat of the U-boats. Thanks to the complexities of that Enigma system, it took an agonisingly long time before any breakthrough could be made. When it came, though, in mid-1941, the result was instantaneous. ‘At a time when the British anti-submarine defences were woefully weak and merchant shipping woefully scarce,’ wrote Professor Hinsley, ‘the use of decrypts to route convoys away from the U-boat patrols had a dramatic effect on the scale of the U-boats’ depredation.’
In both World Wars, the Germans were keen to use their submarines in propaganda – this poster was for an early film called The Enchanted Circle, a phrase actually stolen from Winston Churchill. Goebbels arranged for newsreels of U-boats returning triumphant to ports, while Bletchley desperately sought to crack their codes.
The team in Hut 8 had been given a quantum boost by a brilliant cipher coup in May 1941. First there was the capture of the weather ship München – the crew managed to hurl their Enigma machine overboard but some crucial folders containing information on Enigma settings were overlooked. Then two days later came the dramatic attack upon the submarine U-110 to the south of Iceland which was boarded by a party from HMS Bulldog; despite earlier efforts by U-boat captain Lieutenant Commander Lemp to destroy sensitive material, the sailors moving through the now empty and dark submarine took as much of the boat’s equipment as they could; and in among their haul was a prize the significance of which they would have had little idea: an Enigma machine and cipher books. Although this didn’t quite mean that the Naval Enigma team would be able to unlock codes at will, the haul enabled them to take invaluable shortcuts into regular decryptions. Incidentally, as we will see in chapter fourteen, this U-110 pinch became the source of some controversy 60 years later when Hollywood grabbed the story and transformed it into a tale of American heroism.
The U-boat menace to the convoys was made all the starker by the introduction in 1942 of an even more complex Enigma coding system; Admiral Dönitz, seen here greeting U-boat servicemen, had felt some disquiet about security.
At the start of 1942, Hut 8 faced fresh disaster when Admiral Dönitz ramped up the complexity of Naval Enigma by adding a fourth rotor: the decrypts dried up completely and did so for an appalling few months.
It was only thanks to a tremendous act of sacrifice that the impasse was broken. In late October 1942, on one pitch-dark night, the German U-559 submarine was hit off the coast of Egypt. Able Seaman Colin Grazier and First Lieutenant Tony Fasson of HMS Petard swam naked through the black waters to get into the sinking vessel in order to retrieve any secret material there might have been on board. With terrific bravery – clambering aboard a vessel that was obviously sinking fast – they managed to get down into the freezing darkness, then find and pass water-proofed Enigma codebooks back to canteen assistant Tommy Brown. But then, now knee-deep in water, they also tried to haul equipment out of that blackness – and they were suddenly too late to escape as the submarine finally plunged. They were taken with it. Their courageous action, however, was almost beyond value: those codebooks were the Short Weather Cipher and the Short Signal Book. It took just over three weeks to get them back to Bletchley. And instantly the codebreakers saw the treasure they had – these books in essence gave them an express route into unlocking the four-letter indicators, and thence each day’s Enigma setting. Hut 8 got the books on 13 December 1942. Within just one hour of their first decrypts flowing through, intercepts of U-boat signals were sent through to the Admiralty, enabling them to instantly pinpoint the positions of fifteen U-boats. From that point on, an almost unquantifiable number of lives and vessels were saved as a result. Both men were posthumously awarded the George Cross, and they are commemorated annually in their home towns of Tamworth and Jedburgh. Tommy Brown, who survived (but sadly died in 1945), was awarded the George Medal. A little later, this and a couple of other code breakthroughs ‘so changed the balance of power in the Atlantic,’ wrote veteran Ralph Bennett, ‘that the whole future course of the war in Europe may have hung upon it.’
HMS Petard; one dark night in October 1942, it reached the stricken German submarine U-559, with one clear aim – to snatch Enigma.
Colin Grazier, with Lieutenant Tony Fasson, swam to the U-559 and salvaged the prize, handing Enigma material to 16-year-old Tommy Brown – but Grazier and Fasson paid with their lives. They were posthumously awarded the George Cross.
Lieutenant Tony Fasson (ABOVE), who helped change the course of the war, together with (BELOW) HMS Petard’s young canteen assistant Tommy Brown. Their bravery on that dark night turned Bletchley’s fortunes; and Tommy Brown was also awarded the George Medal for his crucial role. Tony Fasson’s medal is pictured here after it was donated by his family to the National Museum of Scotland.
In the earliest stages of the war, when the cryptographers were still trying to establish some kind of foothold into all the different Enigma codes, from the Army to the Luftwaffe, results were more sporadic; even though, for instance, Bletchley had managed to penetrate the Luftwaffe Red code by the spring of 1940, the decrypts were still only of limited use throughout the Norway campaign and the Battle of Britain; in the case of the latter, intelligence gleaned from aerial reconnaissance and from the ‘Y’ Service listening posts dotted around the south coast was more effective. Those Bletchley out-stations – those Wrens and WAAFS instantly relaying conversations from German pilots – were in essence a sort of human radar.
The Enigma machine out in the field – battery-powered, and with two operators. Each different branch of the German military operation had its own version of Enigma and its coding combinations.
But when the codebreakers started unlocking all the other codes, the flood of traffic and intelligence through Bletchley was awe-inspiring. At its peak in the later years of the war, it was breaking and translating and relaying to intelligence many thousands of messages a day. Even by 1941, this cottage industry was starting to hit industrial scales of production. The sinking of the Bismarck in 1941 was a brilliant early (and obviously top-secret) illustration of what the cryptographers could do. The Bismarck, sailing out from Bergen in Norway, had just sunk HMS Hood, with the loss of thousands of lives; and Bletchley pinpointed Luftwaffe Enigma messages that revealed plans to give the Bismarck air cover. There was another contribution – a sharp observation by Keith Batey in Hut 6. A German Air Officer in the Mediterranean had sent a message to a colleague asking for the whereabouts of the Bismarck because the officer had a close relative on board the ship. The response duly came that she was sailing for France. The hunt for the Bismarck had also been joined by effective aerial reconnaissance and other intelligence. But the fact that Bletchley was so alert to the smallest and most random seeming of messages just showed what a formidable institution it was becoming.
The sinking of the German bat
tleship Bismarck in 1941 was a fantastic national morale boost – but it also lifted spirits at Bletchley Park, where the codebreakers had been invaluable in the effort to hunt it down.
There were also controversies – a belief that Bletchley had to cover up its own amazing successes at any cost, no matter how terrible – that continue to this day, the bombing of Coventry being one of the most vivid examples. The theory, still believed by many, is that the codebreakers had decrypted messages indicating that the city was to be targeted that terrible night in November 1940, and if Churchill had ordered the centre to be evacuated, that would have told the Germans that their secret messages had been read. And this in turn would result in them catastrophically increasing the complexity of their codes. So the city had to be sacrificed in that vast and searing inferno. But against this theory are the facts: there had indeed been messages about the forthcoming raid, but they referred to a mission known only by the term ‘Korn’. This was beyond cryptology – it was an indecipherable key-word known only to a very few. And even by late afternoon on the day of the raid, just hours before the bombers came over, there was still uncertainty at Bletchley and in Whitehall as to whether the target would be London, Birmingham, Derby or Coventry. There was very little that anyone could have done.
An extraordinary decrypt: a pronouncement from Hitler addressed to the crew of the German battleship Bismarck on the day it was sunk. The vessel was finally tracked down thanks to the codebreakers.
There is an even more lurid theory that Bletchley so successfully penetrated the Japanese codes in late 1941 that it knew about the forthcoming attack on the US base Pearl Harbor, and that Churchill forbade anyone to pass the intelligence on because he was desperate for the Americans to come into the war, and only an assault of this scale would make that happen. Again, it seems highly improbable; not least because British codebreakers in the Far East in 1942 utterly failed to interpret the Japanese intention to take Singapore. Rather like the Coventry episode, codes in this case had been successfully broken – but the Japanese used such specialised and abstract terms for their operations that no one could have hoped to have known what they were referring to.
There is no doubting that one of Bletchley Park’s most spectacular triumphs was its contribution to Operation Overlord in 1944. The codebreakers joined with other intelligence departments in playing deadly serious games of bluff and counter-bluff. ‘In wartime,’ said Churchill, ‘truth is so precious that she should always be attended by a bodyguard of lies.’ The aim was to trick the Germans into anticipating that an invasion would be landing not on the beaches of Normandy but in the region of the Pas de Calais. The means was a phalanx of turned agents, false military manoeuvres and deceptive messages. And invisible behind all of this was Bletchley Park; in the run-up to D-Day, the Park’s successful cracking of the Abwehr codes allowed them to know precisely what German intelligence was thinking, and this in turn helped British intelligence formulate further deceptions. The other crucial element for the planning of D-Day was knowing exactly the German military dispositions, and in this the codebreakers, by means of reading military, air force and intelligence keys, scored an uncanny triumph. Obviously the entire enterprise was still fraught with enormous hazard, but the codebreakers of Bletchley Park gave the Allied forces the closest thing they could get to a crystal ball. Indeed, as Professor Hinsley observed many years later: ‘It is a singular fact that before the expedition sailed, the Allied estimate of the number, identification and location of the enemy’s divisions in the west, 58 in all, was accurate in all but two items.’
The Allied North African campaign was greatly boosted by the swift decryptions of the Bletchley out-station team on the outskirts of Cairo. Here the El Alamein bell is rung at the El Alamein Club in Cairo to commemorate the end of the war in Europe
Towards the end of the war, traffic coming through Bletchley Park decreased significantly; the German forces, now pushed back on the defensive, were using landlines more and radio less; as a result, fewer messages were being intercepted. The German High Command was still using Lorenz, though, which gave the Newmanry personnel plenty of ‘Fish’ material to work through. By the spring of 1945, they were listening to the Nazi hierarchy starting to disintegrate. Veterans of Bletchley – codebreakers, Wrens, ATS women – had vivid memories of VE Day, and of the news coming through. Up and down the country, women and men in the ‘Y’ Service stations also recalled how they stepped out, blinking, from the last of their all-night listening shifts, and gazed at the flames of the celebratory bonfires that had been lit. Very few of these veterans would have a proper idea of the impact that their work had had; owing to deep secrecy, and compartmentalisation, right up until the end, such information was out of bounds. And so it was that their wars ended without them quite understanding how vital their contribution had been. A great many were not to know until decades later, when the Bletchley secret at last began to seep out. For some, it was already too late. And even now, the triumphs of Bletchley Park are difficult to quantify.
An historic top secret Ultra decrypt from 1944 – German high command observing (yet also being blindsided by) preparations for Operation Overlord, unaware that their communications and countering plans were being followed minutely by the Allies.
The secret German High Command announcement in May of Hitler’s death, as intercepted and decoded by Bletchley Park.
A chance, finally, to raise a glass. Codebreakers gather together to celebrate VE-Day – although for many of them, their work was to continue long after.
Chapter Eleven
WHAT THE CODEBREAKERS DID NEXT
Alan Turing (RIGHT) at the console of the Mark I computer at Manchester, 1951 – he is with two engineers from arms and electronics company Ferranti, which had been brought in by the government to explore the development of the computer, alongside Professor Max Newman’s theoretical work.
Alan Turing’s typewritten and annotated notes on ‘The Applications of Probability to Cryptology’. His post-war work took him from Hanslope Park to the National Physical Laboratory to Manchester University.
For a great many Britons, the years of World War Two had an intensity that nothing afterwards ever quite matched. For the young men posted to distant foreign lands, or for the young women drafted in to do the heavy industrial work back at home, there was, amid the trauma and the loss, a sense that no day was ever predictable; that there could be emergencies or disaster at any stage. Added to this was the deep focus that came with the feeling that every single individual contribution counted. For the young people of Bletchley, that deep well of excitement was accompanied by the adrenaline-trigger of knowing one’s work was of the highest possible security. And when the war ended? How would one expect these hundreds, thousands of codebreakers and Wrens and linguists to depressurise after years of working at maximum concentration on tasks that meant the difference between life and death for so many?
As with the armed forces abroad, demobilisation at Bletchley Park was a gradual process. The Wrens and the WAAFs started to pack up as the intelligence traffic naturally dropped off – and they were eventually under orders to dismantle the bombe machines ‘wire by wire, screw by screw’, as one veteran recalled. After VE Day, the decryption work still went on – most obviously with the continuing focus on the Japanese codes. Nor did the end of the conflict in Europe mean that the work of codebreakers and listeners was over. Far from it. But the form it would take in peacetime was only an abstract concern to those who were eager to resume their normal civilian studies and careers. The winding down, the thinning out of hut personnel, led to some shift difficulties, as internal memos show: with fewer people around, it was harder for those who remained to be able to get Saturday mornings off for matters such as dental appointments.
Sir Stuart Milner-Barry said that reading German decrypts as they came through was like ‘living with history’; after the war, he returned to his great passion of chess
Some of the codebreakers, partic
ularly senior figures in the directorate, knew by this time that they would be staying on in whatever form the establishment was next to take. But for many of the others, marching out of those gates for the last time, back into a life of regular hours, and work not governed on a 24-hour cycle by an endless procession of nightmarishly random cyphers, that period of readjustment was tricky to negotiate. Normal life was a shade too normal; and on top of this, horizons had been widened.
One of the more illuminating post-war experiences was that of the young mathematician John Herivel, whose brilliant insight in 1940 led to the Park unlocking the Luftwaffe Enigma pretty much until 1945. Herivel left the Park and moved to Northern Ireland to teach. The experience was extremely unsatisfactory: he had to give it up when he realised that he had no control over the boys he was supposed to be teaching. To have moved from the collegiate anarchy of Bletchley to the uncongenial anarchy of school must have seemed at best a disappointment. Herivel then moved into academia, taking up a position as a lecturer in the History and Philosophy of Science at Queen’s University Belfast. He also went on to write several books, including Joseph Fournier: The Man and the Physicist. Herivel’s father had no idea what his son had done during the war, and the codebreaker was determined not to break the Official Secrets Act, no matter what the circumstances. On his deathbed, he accused his son of having ‘achieved nothing’ during the war. Heartbreakingly, he could not tell his dying father the truth.