The Secret Life of Bletchley Park (15 page)

For others, though, like Jean Valentine – a young Wren who later went on to break Japanese codes in Ceylon – the thing was simply to take a deep breath and get on with it. ‘I was sent to Adstock, living in a village called Steeple Claydon, and started working on the bombe. We worked shifts, or “watches” as they were called; eight in the morning till four in the afternoon for one week; four in the afternoon till midnight the following week; and then midnight till eight on the third week. Then we went off duty at eight in the morning and were back on at four till midnight, so we did sixteen hours that last day. Once you had learned how to [work the bombe], it was OK. It wasn’t all that complicated.’

Jean Valentine says that – speaking for herself – she saw few signs that working on these great machines was more stressful than any other part of the war effort. ‘Yes, there was a call for accuracy, but that was discipline. You disciplined yourself to do it because you were being disciplined. There was nothing serious done to us but it was the expectations on us as youngsters.

‘When you’re younger, your fingers are very flexible, you can do things much more quickly. And the brain works quicker.’

On top of this, many have testified to the unendurable noise of the bombe machines working hour after hour. Again, Jean Valentine remembers slightly differently: ‘I don’t like noise. But to me, it was like a lot of knitting machines working – a kind of tickety-clickety noise. It was repetitive but I can’t say I found it upsettingly noisy. In fact, the bombe reconstruction in the Bletchley Park Museum sounds a lot noisier to me than a room full of five of them.’

One other side-effect of the work, says Jean Valentine, was apparent when she went home. And it was another indicator of the general discretion of the time that this did not prompt more questions: ‘My mother never questioned anything, but she did say to me once: “What are you doing to your shirt cuffs?” I used to take my washing home and the cuffs would be all black. It was the fine spray of oil, which you couldn’t even see so you didn’t know it was happening, a spray coming off the bombes.

‘So I just said, “Oh, it’s the work I’m doing.” And my mother didn’t pursue it.’

‘Ultra never mentioned Coventry,’ commented Air Section head Peter Calvocoressi. ‘Churchill – so far from pondering whether to save Coventry or safeguard Ultra – was under the impression that the raid was to be on London.’
¹

The German raid on Coventry on the night of 14 November 1940 is still the cause of debate and controversy today. Thanks to a pointed reference by Captain Winterbotham in his pioneering book on Ultra, the theory that Churchill allowed the Midlands city to burn – in order that the Germans wouldn’t suspect that Bletchley had broken into Enigma – has continually reappeared. And even though most Bletchley Park veterans firmly believe that the theory is nonsense, a few are not so sure. But in order to get a better idea of the searing events of that night, it is necessary to explain a little of the background, and of the increasing value of the intelligence that Bletchley was providing, through the Battle of Britain and beyond.

Back in the summer of 1940, huge numbers of people in Britain had been bracing themselves for what seemed the inevitable. The Germans, triumphant in France and the Low Countries, would, it was popularly believed, now turn to Britain. There was little belief
that in the event of an invasion, Hitler’s forces could be successfully fought off. Such pessimism would very rarely be heard out loud; one wouldn’t want to be reported for damaging morale. Neverthe less, to read contemporary diaries, and to hear contemporary accounts, it is clear that a great many people were sick with anxiety about what they saw as Hitler’s coming victory.

Little wonder; nothing like the German war machine had been seen before. Added to this was the calculated sadism, together with the way that any conquered nation would be subject to the paranoia of informers and curfews, the terror of random public executions. News of what had been happening in Poland had come back to London. To listen to Churchill’s speeches now, one simply hears the growl of inspirational defiance. But as Mimi Gallilee says, whenever she went to bed after a day’s work at Bletchley, she would ‘pray first, and pray hard’. She and countless others lived in real fear of a lightning invasion.

Secret preparations were made for such an eventuality. Among them was the recruitment of the ‘Scallywags’, outwardly passive-looking men such as clerics, writers and intellectuals, trained in techniques of subversion and assassination, with the aim of starting as much mayhem as possible. But when would Hitler invade? From the Cabinet and MI6, down to the saloon bar debaters in the Anchor and Crown, it was a subject of intense speculation based upon little more than guesswork.

In August, in preparation for Operation Sea Lion, the Luftwaffe launched a ferocious concerted attack from the air upon RAF airfields and radar stations. Yet in the succeeding weeks, during what became known as the Battle of Britain, the RAF pulled off astonishing repeated triumphs in its airborne skirmishes with the enemy. The image is ceaselessly evocative; that of the people of Kent looking up into a wide, pale blue sky to see, far above, the tiny forms of Spitfires firing upon the encroaching enemy, and of German planes spiralling downwards, their bailed-out pilots floating down on para chutes.

The end of August brought the conclusion of the Battle of Britain, and with it not merely a sense of relief but also a valuable raising of spirits. Churchill now gave the command for an air raid on Berlin. This in turn led Hitler to order the Luftwaffe to begin an even stronger attack on London. The unforeseen side-effect of this German strategy, however, was that it relieved pressure on the RAF airfields which previously had been the Luftwaffe’s main targets.

As mentioned before, Bletchley Park could offer little in the way of practical help to the air force at this time. However, come September, one particular decrypt was of great tactical importance. The message ordered the dismantling of air-lifting equipment on Dutch airfields. Its meaning was very swiftly deduced by the Chiefs of Staff: Operation Sea Lion was to be postponed.

In other words, the Few had succeeded brilliantly; the Luftwaffe having been repelled, there was little chance, with the season of storms now upon the English Channel, that the Germans could launch an effective troop landing. Hitler, the Chiefs calculated, would have to shelve preparations for the winter. It was precisely this sort of information, provided by Bletchley, that gave the forces what was termed a ‘crystal ball’. ‘So efficient did Bletchley become in handling this material,’ wrote Aileen Clayton, ‘that there were even cases where, during poor conditions for reception, the German recipient of a signal was obliged to ask the sender for the message to be repeated, whereas our listening stations had recorded it fully the first time. This placed British Intelligence in the position of knowing the contents of a signal before the intended recipient.’
²

By late September, Hitler was starting to turn his attentions east, towards his projected invasion of Russia. Although the Luftwaffe had lost a great many men and planes throughout the Battle of Britain, however, this did not stop their aerial bombing campaign.

The Blitz started on the afternoon of 7 September 1940. Dread-filled Londoners gradually became aware of a distant muffled roar,
like thunder, approaching from the east as 350 German bombers darkened the horizon. The RAF, expecting an assault on their bases, had missed the attackers. Within minutes, the German planes were flying over the vast docks and warehouses of east London. As they dropped their incendiary bombs, the warehouses, filled with imported sugar, molasses and timber, went up in a series of blossoming yellow and blue infernos.

The daylight raids were not to continue, for too many of the German planes were picked off on their way back to base. But nightly bombing soon began, and even though the darkness hampered much of the Luftwaffe’s accuracy, the result was still devastation, and a population forced to seek shelter and sleep far underground in Tube stations. It was, and remains, unimaginably relentless – in the following months, some 19,000 tons of bombs fell on London alone.

But with the coming of that ferocious onslaught to London, the cryptographers at Bletchley made a further breakthrough. Crucially, the Germans sent information about their bombers’ navigation beams – the beams that were supposed to keep them on course – via radio. These radio signals were picked up by the Y Services. And on being passed on to Bletchley, a new colour of Enigma decrypt – ‘Brown’, for this section of the Luftwaffe – was assigned to the specific cracking of such messages.

The operatives of Hut 6 rapidly succeeded in doing so. Within days the Air Ministry was receiving vital information concerning potential raids and the numbers of bombers that might be involved. Thanks to Enigma, as Oliver Lawn explains, the Air Ministry also had the wherewithal to ‘bend’ the German navigation beams, thereby causing the planes to drop their loads in the wrong places: ‘One of the things the Germans used the Enigma machine for, in the early stages of the war, was directing their bombing of British cities – beam bombing. That’s an aeroplane going along a beam and another beam being set to cross it. And that was the point at which they dropped their bombs, over the centre of the city

‘Now, there was a code which set the angles of the beams. And if you could break the code, clever engineers could bend one of the beams so that the crossing point was over green fields, and not over cities.’

London, of course, was not alone in bearing the brunt of the nightly assaults; British industrial cities from Birmingham and Liverpool to Manchester and Glasgow lived in expectation of receiving hits. The information Bletchley supplied was never conclusive, but they were able to identify squadrons and call-signs and thus report on numbers. However, Bletchley Park was not able in 1940 to accurately identify disguised place names in messages. For that, what would be needed was not a bombe, but a physical codebook, for aliases are simply impossible to guess at.

Thus the war acquired a new and terrible urgency. The deployment of British troops in foreign lands was one thing; the targeting of ordinary citizens in large cities – in other words, total war – was another. Although much was made at the time of the claim that ‘Britain can take it!’, the true effect upon morale, especially among the East Enders whose houses and streets were being flattened on a nightly basis, was more difficult to gauge.

British government psychologists were extremely concerned about the possible effects upon large urban populations of subjection to Blitzkrieg of the kind suffered in Spain and Norway. Mass panic was predicted, along with a breakdown of law and order, and the development of a sort of collective psychosis. In fact, those first Luftwaffe raids upon London had demonstrated something quite different; a tangible sense of defiance among all the smouldering bricks and the shattered houses. But London was a vast city. What would be the effect in a smaller, perhaps more tightly knit community?

The RAF campaign against German cities stepped up. That autumn, British bombers aimed for Munich and for arms factories in Essen; they also bombed Hamburg. In response, German
bombers started roving more widely across Britain. And in November 1940, one particular raid led to a conspiracy theory involving Bletchley Park that has persisted to this day.

The story, according to ‘end-of-war’ reports from Bletchley itself, seemed to go like this: thanks to a ‘Brown’ message decrypt from Enigma on 11 November 1940, the Park was able to tell Air Intelligence that there was to be a very heavy raid. The codename given to this raid was ‘Moonlight Sonata’; the reason for the name was that it was apparently to take place at the height of the full moon. The German planes would be led by navigation beams. And there was a list of four potential targets, each of which had been given codenames. One of the codenames was ‘Korn’.

Just earlier, a German prisoner of war had told his interrogators that a heavy raid was planned on Birmingham or Coventry. On 12 November, a ‘Brown’ Enigma decrypt seemed to give navigation beam bearings showing that three of the potential targets were the heavily industrialised Midlands cities of Birmingham, Wolverhampton and Coventry. The date for the raid was most likely to be the 15th.

And so with this information, gleaned from Bletchley, Air Intelligence reported to the Prime Minister on the morning of the 14th, telling him that the target was possibly London – given the sheer size of the raid planned – but could also either be Coventry or Birmingham. After all, no one could know what the code word ‘Korn’ signified. Both Midlands cities were likely targets, as both had high concentrations of manufacturing plants directly involved with the war effort. In the case of Coventry, many of these factories were within the bounds of the city centre. As targets on a brightly moonlit night, they could hardly be easier.

By 3 p.m. that day, radio signals finally made it clear that Coventry was to be the target, and that the raid was to take place that night.

This is where the conspiracy theory begins. Why, it goes, were the people of Coventry given no warning? Why was no attempt made to stop a raid that loosed thousands of incendiaries and tons of high
explosives, creating a hellish blaze that destroyed almost everything within the radius of a quarter of a mile, even the city’s cathedral? In other words, why was the old city of Coventry sacrificed in this conflagration?

The reason, say the conspiracy theorists, is this: that to have deflected the bombing by sabotaging the navigation beams – or allowing RAF fighters to defend the city from the air – Churchill would have been effectively telling the Germans that he had access to their most secret transmissions. The Prime Minister, this theory goes, was therefore faced on 14 November with a hideous dilemma. Could he step in with this foreknowledge and order that Coventry be given full protection from the onslaught – but by doing so alert the enemy to the fact that its messages had been read? Or instead, should he allow the city to be put to the sword so that the secret of Bletchley remained unguessed at?