Although still only a junior researcher, Jones was caught up in the rivalry between Lindemann, on the one hand, and Sir Henry Tizard and Robert Watson-Watt, on the other. His academic research was brought to a close and Watson-Watt arranged for him to be recruited as a civil servant in the Air Ministry. Jones was reluctant to leave Oxford and felt he had become ‘a pawn in a distinctly unpleasant game’.3 In fact, it was the best thing that could have happened to him as well as to British wartime science, for it brought Jones into the top secret world of the intelligence community.
There had never been a scientist in Air Ministry Intelligence before, and over the next few years Jones gained a fast-track grounding in the military application of science. He worked with most of the leading figures in pre-war military science and did stints for both the navy and the RAF. When war came, Jones completed his crash course with a placement to Bletchley Park. Here, the mysteries of the German Enigma machine were explained to him and he spent some time with the brilliant young Cambridge mathematician, Alan Turing, who was already starting to devise ways of breaking the seemingly impenetrable codes that the Germans were using. Two months after the declaration of war, in November 1939, Jones was sent back from Bletchley Park to 54 Broadway, near Victoria, the headquarters of the SIS, and it was here that late one afternoon Winterbotham passed on to him the parcel containing the Oslo Report.
The task Jones had been given was to obtain early warning of any new weapons or systems the enemy might be developing for use against Britain or British forces. He was staggered at how little real scientific intelligence had been gathered before the war; in particular the lack of knowledge about the Germans’ development of radar. He was convinced that the Germans were using radar, a belief confirmed by the Oslo Report, but he could get no one to believe him. So, despite the warning in the report about the use of radar to pick up bombers heading for Wilhelmshaven, another raid went ahead in December, resulting in the dreadful losses described earlier.
Jones’s wide-ranging experience in the run-up to war gave him the confidence to say what he thought and to stick his neck above the scientific parapet when be believed he was right. The first real occasion for this came in June 1940. Before the Battle of Britain had begun, Jones thought he had picked up indications that the Germans were using a system of beams to guide bombers to their targets. The beams could work by day or night and in all weathers. He had been given details of various intercepted messages referring to a system described as Knickebein which, puzzlingly, translated as ‘crooked leg’. It appeared to be linked to a radio transmitting station at Cleves. Jones reported his fears to Professor Lindemann, who by this time was running a special unit in Downing Street to advise Churchill, recently appointed Prime Minister. Lindemann was sceptical as he believed short wave beams could not travel far as they could not follow the curvature of the earth. Jones had to find more evidence for his theory.
Jones got one of his colleagues, Squadron Leader Denys Felkin, who ran an interrogation centre for captured Luftwaffe PoWs, to ask them about the Knickebein system. But they would say nothing. Then, talking among themselves, one pilot was overheard saying to another that no matter how hard the British looked, they would never find the system. This comment was secretly recorded and passed on to Jones. It gave him the clue that maybe Knickebein was not some additional piece of kit but existed within the radio equipment already in use in German bombers. Technicians examined a Heinkel III bomber that had come down in Scotland and found it contained a blind landing system developed by the Lorenz company that was intended to help aircraft line up with the runway in bad weather conditions. However, it appeared that the receiver was far more sensitive than it needed to be for such a purpose. Jones believed he had found the device the Germans were using to guide the bombers to their targets. He went back to Lindemann, who was now persuaded to take the idea seriously.
Lindemann passed this information on to Churchill, who immediately recognised the importance of such a discovery and was keen to explore the problem further. Fearing that it would get bogged down in endless bureaucratic delays, Churchill called several senior figures to an urgent meeting. Present were the Minister for Air, Sir Archibald Sinclair, the Minister for Aircraft Production, Lord Beaverbrook, both Lindemann and Tizard, Watson-Watt and several senior RAF figures, including the Chief of the Air Staff and Sir Hugh Dowding, the head of Fighter Command. The meeting was called for 21 June in the Cabinet Room. Arriving at work that morning, Jones received a summons to attend the meeting with the Prime Minister but as a renowned practical joker he thought this was his friends getting their own back and did nothing. When he realised it was no joke he rushed to Downing Street, but arrived half an hour after the meeting had started. It was his first meeting with the PM, and this was not a good start.
When Jones entered the Cabinet Room, he found Churchill, Lindemann and Beaverbrook seated on one side of a long table, with Tizard, Watson-Watt and the RAF folk down the other side. Jones detected a tense atmosphere in the room, almost a sense of confrontation. So he decided to sit across one end of the table in a sort of no-man’s-land between the two sides. He realised in the next few minutes of conversation that no one had grasped the situation accurately, so when Churchill turned to ask him a point of detail, Jones said, ‘Would it be a help, sir, if I told the story right from the start?’
Churchill was rather taken aback but replied, ‘Well, yes it would.’
The twenty-eight-year-old, confident that he alone understood the whole picture, then spoke for about twenty minutes in front of the nation’s top political leaders and the top brass of the RAF, a long time to hold the attention of such senior men in the midst of a grave national crisis. Coolly recounting his suspicions, he explained how he had raised his concerns and deduced that the beam reading system was part of the Lorenz blind landing mechanism. Churchill later wrote, ‘For twenty minutes or more he spoke in quiet tones, unrolling his chain of circumstantial evidence, the like of which for its convincing fascination was never surpassed by the tales of Sherlock Holmes.’4
When Jones fell silent, Churchill asked him what could be done. The young man replied that first an RAF aircraft must fly with the captured equipment and see if it could navigate along the beams. Then, attempts must be made to put in a false cross-beam to get the German bombers to drop their bombs miles off target. Another option was to consider jamming the beams. There was a general air of incredulity among the RAF chiefs, who raised various objections. Churchill flew into a rage and banged the table angrily, exclaiming, ‘All I get from the Air Ministry is files, files, files.’ The young scientist had at least offered him a programme of action. Churchill demanded that counter-measures be explored as a priority and the meeting broke up. What was later called the Battle of the Beams now began.5
Jones had been correct in his belief about the use of the beams and once their operation had been fully understood it was possible for the scientists at TRE to work out ways to jam them and to throw the German bombers off course. The first round in the Battle of the Beams had gone to Jones and the British radio scientists. But as the Blitz began in earnest, the Germans soon realised their secret had been uncovered. They started to use a far more complex system of five very high frequency short wave radio beams that when intersected by another beam provided key Pathfinder aircraft with an accurate siting to within a hundred yards of a target. The second round belonged to the German scientists. British radio operators could pick up the existence of the beams but were unable to work out where they were pointing.
On the night of 14 November, a big raid was predicted, but its target remained unknown. That night the Luftwaffe carried out their biggest raid outside London on the city of Coventry: 554 men and women were killed and more than twenty factories around the city, along with hundreds of homes, were destroyed.
Eventually, during the winter of 1940–1, the boffins at TRE found a way of reading the beams and warning where the raiders were heading. But even before a victory h
ad been called in this round, the Germans began to use the new device called the Y-Gerät, or Y-Apparatus, using a sophisticated form of radar to guide their bombers to the target. This too was hacked into and distorted and it is thought that the bombing of Dublin in neutral Ireland in May 1941 was a consequence of twisting the radar beams that were guiding the German bombers. Interestingly, for Jones, an early form of the Y-Gerät had been described in the Oslo Report. He was glad he had kept his copy.
The Battle of the Beams made it absolutely clear not only that the Germans had radar but that they were capable of using it in inventive and ingenious ways. But there were still some doubters in the intelligence community. So while still struggling with the beams, the next round in Jones’s secret war began in July 1940 when his team began to pick up radio signals that suggested at least two German radar stations were in operation, one on the westernmost tip of the Cherbourg peninsula near Auderville and a second further west on the Brittany coast near Lannion. During the autumn and winter of 1940–1, Derek Garrard from TRE, who had been assigned to work for Jones, went down to the south coast with his own receiver to listen in to various frequencies. At one point, setting up his strange receivers in a forbidden area, he was arrested as a spy, though Jones soon got him released. Garrard not only picked up the transmissions but was even able to find fairly precise bearings which confirmed where they were coming from.
Jones found it difficult to make sense of all the different systems that appeared to be in operation for the Wehrmacht, the Kriegsmarine and the Luftwaffe. He was struggling with the fact that German radar had been developed by several different companies using different wavelengths. But he realised that the generic term in use was DT (Dezimeter Telegraphie). The Kriegsmarine seemed to be using one system to target coastal guns against British shipping in the Channel on a wavelength of 80 cm. Another system was in use to provide early warning against the arrival of British aircraft over occupied France. Intercepted signals suggested that the principal form of this radar was named Freya. Jones initially calculated that it had a range of about 90 miles. Jones realised that with the fall of France, the Germans had simply moved the Freya radar stations that had guarded their western border, en masse, to the Channel coast.
It greatly helped that before proper telephone landlines were laid to connect all these stations, they broadcast to each other and to their controllers on open radio frequencies. They adopted a very basic code and it was soon possible to break this and read the communications. Jones was able to further deduce that the Germans had no integrated system for aircraft early warning such as that created for RAF Fighter Command in Britain. Instead, they had simply ‘grafted the new development on to a well established system [of the Observer Corps]’.6 But it was still impossible to calculate how the Freya stations operated.
Abandoning its previous policy of complete secrecy, the government decided in June 1941, following leaks in Canada, to reveal the existence of its radar programme. On 18 June, the Deputy Prime Minister, Clement Attlee, made a short speech in the House of Commons admitting the existence of a new science of ‘radiolocation’ that was in use to detect the approach of enemy aircraft. Not much was said as to how it operated, but Attlee made clear that it had been in development for many years. The announcement was linked to a call for volunteers from around the Empire to come forward to train as operators. The press picked this up and on 29 June, the Sunday Times ran a recruiting ad for the WAAF: ‘Radiolocation – one of the best kept secrets of the war. It helped to win the Battle of Britain and it’s going to win many more battles for the Royal Air Force.’ Quoting a supposed WAAF operator, the ad continued, ‘I can’t tell you just what I’m doing [but]… The Radiolocator sends out electric waves that patrol the air. The waves radio messages back to me.’ The ad clearly admitted that ‘Radiolocation is a brand new science… it may well be the “discovery of the century”.’ The work was presented as being exacting and exciting, with enormous possibilities after the war when ‘trained operators will be invaluable’.7
It was a curious decision to come clean about the new science at the heart of Britain’s air defence. But the British public now knew about this new-fangled activity and that its operation was in the hands of WAAFs, who had shown great courage when under fire in radar installations the previous summer. And the new word ‘radiolocation’ had entered the English language.
During the summer of 1941, the War Cabinet resolved to commit Bomber Command to a policy of night bombing, both in occupied Europe and in Germany itself. Air Vice Marshal Charles Medhurst, assistant to the Chief of Air Staff in charge of intelligence and Jones’s boss, asked him to compile a picture of the German night defences that the RAF bombers would encounter. The control of these defences was likely to depend very largely on radar, just as Britain’s defence had done during the Battle of Britain and the Blitz. Jones would have to find out how the whole complex German defensive radar shield fitted together.
On 22 November a vital breakthrough came when Jones saw two aerial photos that recorded a couple of strange, circular objects near the coast at Auderville. Photo interpreters had measured the two unknown sites as being about twenty feet in diameter. Moreover, the hawk-eyed interpreters had spotted that in the gap of a few seconds between the exposure of the two photographs, the shadow of the objects had moved fractionally. Using magnifying equipment, they measured a broadening of the shadows of about one-tenth of a millimetre between the two pictures. From such tiny measurements, major conclusions were drawn. The photo interpreters suggested that the aerials might be rotating and were therefore unlike any other radio towers that had yet been detected. Jones realised that this might be the first sighting of a Freya radar station and asked for further low-level photography of the site.
The taking of aerial photographs was still a young science. The RAF had only begun to use Spitfires, the fastest aircraft available, for the task a matter of months before. The principle of aerial photography in wartime was for a reconnaissance aircraft to fly fast and high at about 30,000 feet over enemy territory and for the pilot to turn on his cameras when he was above the target area. All the guns and the armour plating were taken out of the photo recon Spitfires to make room for the cameras and lenses, and to lighten the aircraft in order to give it extra speed and height. They flew above the range of the anti-aircraft batteries, but if an interceptor came up in pursuit, the recon pilot had to turn on full throttle and head for home. He could not stop to fight as he had no guns. It took particular bravery to be a reconnaissance pilot, flying for hours on end over enemy territory in order to get his photos and then having to make his way home again with nothing but his speed and his daring to get away from any fighters sent up to intercept.8
Occasionally photographs taken from such a great height were not suitable, as they were at too small a scale, and it was necessary for a pilot to fly a low-level sortie at maybe just 100 feet in order to get a detailed close-up picture of an object on the ground. These sorties were enormously dangerous, as they brought the aircraft within range of the anti-aircraft guns and any enemy fighters that happened to be in the area. In RAF parlance these sorties were known as ‘dicing’ missions – short for ‘dicing with death’. Aware of the risks, Jones now asked with suitable diffidence for a low-level ‘dicing’ sortie to be made over the circular objects near Auderville.
The first such mission was a failure as the aircraft flew at nearly 350 mph past the radar emplacements on the ground. Pilots were always told they could never have two goes at a ‘dicing’ mission as if you went back a second time, the enemy’s gunners would be waiting for you. The pilot of the first sortie thought the object he had been asked to photograph itself looked like an anti-aircraft gun emplacement and reported with some irritation that he had been sent on a crazy suicide mission. But Jones was sure of himself and requested a second low-level sortie. It was on this mission, on 22 February 1941, that Flying Officer William Manifould took a magnificent oblique photograph from about 200 fe
et that clearly showed the two radar aerials and three rectangular support buildings nearby.
Realising from these shots what the photographic signature of a Freya radar station looked like, the photo interpreters managed to identify more and more of the stations that made up the German radar chain along the Channel coast. Meanwhile, the specialists at TRE were able to measure the wavelength of the radar signals, the intensity of the pulse transmissions and the method by which the detections were reported from the isolated stations.
In the summer of 1941 investigation of the sites went a stage further. Pilots made test flights from the south coast of England, TRE tuned in its listening devices and was able to follow the whole process as the Freya operators went on to alert, found the RAF aircraft on each occasion and monitored it in their reports. The accuracy of the German range and bearing identification could be carefully plotted. From these it seemed that the Freya radar was not good at measuring the height of approaching aircraft.
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