Most Secret War

by R. V. Jones

  Even with this failure of Intelligence, however, the SN2 nightfighters would probably have been relatively unsuccessful had we been more careful in our use of radio and radar, as was indicated by our low losses on the nights on which the ground controllers failed to put the fighters into the bomber stream. In the event, Bomber Command was pulled back for the time being from raiding Germany during April and May 1944, because its effort was needed against targets connected with our impending landings in Normandy.

  Fig. 24. One of a set of sketches made by a Belgium patriot (a Brussels jeweller) who spent every night for a week in a German fighter control station which used the Y-system for locating its fighters. This sketch shows the details of the ‘Seeburg’ plotting table on which the positions of the bomber and the fighter were projected as spots of light, and from which the controller issued orders to the fighter

  A further brilliant item of Belgian Intelligence that arrived early in 1944 may fittingly conclude this chapter. The Y-ranging system that von Lossberg had brought in for nightfighters was also applied to day-fighters, and complete stations for controlling dayfighters on the Y system were built. Since each equipment could handle only a few fighters at a time, as many as five complete ranging equipments and their plotting tables were incorporated into a single station. One of these was at Lantin, in Belgium, and a Brussels jeweller decided to investigate it for us. Surprisingly, it was not used by the Germans at night, and so the German personnel left it under a guard of Belgians who had been recruited into the S.S. Our jeweller friend bribed one of these men to let him into the station at night, and he spent every night for a week there, sketching everything that he could see. His sketches came to me, and one of them is reproduced in figure 24. The excellence of his draughtsmanship will be evident, especially when it is remembered that he was sitting alone in the German headquarters, with always the chance that one of the Germans might return. His sketch of the Seeburg (plotting) table gave us easily the best detail that we obtained until we at last captured specimens towards the end of the war.

  CHAPTER FORTY-TWO

  The Baby Blitz

  OUR WARNING of 23rd December 1943 that there was a German bomber force concentrating in the West, and that this might have been assembled as a substitute should the flying bomb be delayed, was proved correct by the entries in Milch’s diary. These show that the performance of the prototype bombs in trials had been disappointing; and an R.A.F. attack on Cassel on 23rd October had forced the evacuation of the Fieseler Works where the pilot series of flying bombs was being manufactured. In November it was estimated that another 150 bombs would have to be tested before the trials would prove satisfactory, and excuses had to be made to Hitler for the delay. On 27th November Goering promised him that the Luftwaffe would mount a heavy attack on London within two weeks in revenge for the raids on Berlin; but even then he had to delay, so the first attack did not take place until 21st January. It was the start of what came to be known as the ‘Baby Blitz’, which continued in a desultory manner until it fizzled out at the end of April 1944.

  To me the Baby Blitz was memorable for two incidents. The first was the birth of our son, Robert Bruce, on 11th February, at home in Richmond, and with Vera and me and the two children having on various nights in the subsequent weeks to revert to sleeping on the floor with our heads protected by our dining table. The second incident started with the impression gained by our listening service that the fighter bombers sent over by the Germans were being controlled by a new method. Actually, it was much along the lines that the Telecommunications Research Establishment had suggested when in 1942 they would not believe me that the Mammuts (or ‘Hoardings’) were simply radar stations, because the precision of their transmissions was unnecessarily high. I had, of course, been able to show that they were not distinguished in this respect from any other kind of German radar station, but it helped to alert me to the possibility that at any time any German radar station, at least of the Freya type, was capable of directing bombers, especially if it were fitted with a device such as our own I.F.F.

  The Germans now had such a device in the Funk Gerät 25A, and we soon heard transmissions from it on the fighter bombers that were hurtling across London. The method was to set a Freya station on the coast of France so that its split-beam pointed over the target in London (Figure 25). The aircraft then flew along the beam, being guided by verbal instructions by the radar operator, who having steered the aircraft along the beam to an appropriate range and having told him to fly at a given speed and height, then told the pilot when to release his bombs or flares.

  At first the attacks were very scattered. In two raids on London (21st and 29th January) some 500 tons of bombs were dropped, with less than 40 tons hitting London, for the loss of 57 aircraft, or nearly eight percent of the sorties. But in one of these early attacks a few bombs fell fairly near Whitehall, which caused more interest at the top level than might otherwise have been the case, and once again I found myself summoned to the Cabinet Room. This time I was able to tell the Prime Minister not only of the German technique, as I suspected it, but also to give him the names of one or two of the German pilots.

  We discussed possible countermeasures, especially in view of the fact that the Germans were at last dropping ‘Window’, and a few of them were even using captured Gee receivers of ours by which they could navigate on our own Gee stations. It occurred to me that we could play exactly the same trick on the Germans as they were playing on Bomber Command, for they had to have their I.F.F. sets on while they were being controlled from the radar stations in France. If we could make challenging transmitters and receivers, we could thus locate the bombers through any amount of ‘Window’, just as the Germans were doing against us. When Churchill grasped the point he said ‘Let it be done!’

  Once I had produced the idea, it was technically no longer my responsibility, but that of the research and countermeasures organizations. And so in the follow-up meeting in the Cabinet Room a week later, when my proposal came up as an item on the agenda for the review of progress in its exploitation, Churchill looked at Robert Renwick, whose care the development now was. Just as Renwick started—quite properly—to speak, however, I saw Attlee, who was sitting next to Churchill, nudge him and whisper something and point to me. Churchill thereupon stopped Renwick and invited me to speak. I of course referred the matter back to Renwick, but I was much impressed by Attlee’s memory and sense of fair play in that he had gone out of his way to see that I was to get the credit for the suggestion, even in a technical matter that must have been quite beyond him.

  Fig. 25. The bombing system used in the ‘Baby Blitz’, January/March 1944

  As it worked out, the method was an extremely powerful one, and even a single challenging station could plot the German aircraft, even though they were dropping ‘Window’, over the whole of southern England. It was not in fact much used because by the time it was ready the Baby Blitz, which fizzled out in April, was nearly over. But the lesson had been learned, for it was adapted for our intruding nightfighters to use against the German nightfighters if they had their I.F.F.’s on. Under the name of ‘Perfectos’ it was described by Alfred Price in Instruments of Darkness, p. 220, as one of the neatest electronic gadgets to come out of the Second World War. It achieved little tangible success, but it forced the German nightfighters to switch off their recognition sets, so complicating the tasks of their ground controllers.

  Spring came as the Baby Blitz ended, and I was able to take a happy weekend with Hugh Smith in Gloucestershire. We awoke to see in the garden across the road someone who was familiar to us in Whitehall. He was Major Kingdon, one of our colleagues in M.I.8, the branch of Military Intelligence concerned with intercepting enemy radio communications. It turned out that by coincidence Hugh Smith’s neighbour, Captain Rogers, had just joined the same branch and he had invited Kingdon, who was the Head of his Section, to the same village for the weekend. The weather was beautiful, the orchards of the Vale of Evesham w
ere at their blooming best, and the two Military Intelligence officers had come to hear the first cuckoo. I myself have some competence in the art of cuckoo-ing—I used to try to persuade Susan to sleep with it, so much so in fact that one day in Richmond Park she heard a genuine cuckoo call and immediately said ‘Mummy, Mummy, Daddy’s up a tree!’ Hugh and I enlisted the services of the lads of the village and, for a shilling a head, our military colleagues heard cuckoos in quantities that would have found Dame Juliana Berners speechless.

  CHAPTER FORTY-THREE

  D-Day

  AT THE same time as we were watching the flying bomb trials, dealing with the Baby Blitz, and wrestling with the German night defences, another problem was approaching its climax: this was the coming operation to land in force in Normandy. Ever since 1940 I had known what my part must be, whether or not it was formally assigned to me: to see that everything possible was done to knock out, by jamming, deception, or direct action, the chain of coastal radar stations that the Germans would inevitably build up. This had been my answer in 1941 to A. P. Rowe when he asked me what good it was my collecting detailed Intelligence on all German radar stations: some time, I had replied, we were going back and those stations might stand between our success and failure.

  In general by the end of 1943 we knew enough about the various forms of coastal radar to jam much of the system successfully, and to organize deceptions by using ‘Window’ to simulate large forces at sea as well as in the air. But if we could make direct attacks on German radar stations, some of them could be eliminated, and the operators in the others might be so disturbed as to observe less accurately in the presence of jamming and ‘Window’. From the beginning, therefore, I had advocated direct attack.

  Fighter Command at first said that it could not carry out attacks on such small targets as radar stations because fighters could not find them. I therefore suggested that each fighter squadron should be led by a photo reconnaissance pilot, and this suggestion may have shamed the Command into improving its low-level navigation. Anyway, by the beginning of 1944 there was serious consideration of using fighter squadrons against the radar stations in the Invasion area.

  The work of building up the information about the positions and types of German radar equipment on the coast was shared between my unit and Claude Wavell’s in the Central Interpretation Unit at Medmenham, and over the years we had jointly produced a series of dossiers for what were known as ‘Rhubarb’ operations, these being the general title of any offensive actions by Fighter Command over France and the Low Countries. To the general operational instructions there was a series of appendices, and ours was Appendix XII, of which we produced several editions as the intensity of German radar cover increased. The result was that, although we never had an operational requirement stated to us, there was a comprehensive dossier on every German coastal radar station, including maps, and high- and low-level photographs, in sufficient detail for accurate attacks to be planned.

  Moreover, we produced recognition drawings of all known types of German radar equipment, and catalogues of all the radar stations between Skagen at the northern tip of Denmark, and Bayonne on the west of France near the Spanish frontier. Even though we knew that the attack was to be made in Normandy, we covered a very much wider coastline, so that if any leakage of information were to occur, the Germans would have no clue regarding the selected area. Our catalogue listed nearly two hundred separate stations which between them contained some six hundred individual radar installations.

  We were now producing many copies of our reports—more than three hundred of each were circulated to headquarters and field units, both British and American, and we supplied the information for all three Services of both nations. In this, we had the enthusiastic support, particularly, of the United States Navy; but, even as late as March 1944, I still had no formal request for information on German radar, nor was I formally brought into the Invasion planning. At last, an officer who had been on the first Course to which I had lectured at the R.A.F. Staff College, came in to consult me, since he had officially been assigned to the problem of knocking out the German radar. But it was clear that his scale of operations would be much too small to be effective. I was therefore wondering how I could intervene, when I had to give a further lecture at the Staff College on 13th April 1944. When I arrived there, Charles Medhurst told me that Sir Arthur Tedder, the Deputy Supreme Allied Commander, would be giving the lecture after mine, and Medhurst wondered whether I would care to listen to him before we all went to lunch. I told Medhurst that Tedder was just the man I wanted to see, because of the inadequate planning of countermeasures against German radar, and that I would like a chance to talk with him. Medhurst, once again delighted to be able to ‘fix’ something, told me that he would see if he could arrange for a quiet half-hour between me and Tedder after lunch.

  He left the two of us in his room, and I told the Deputy Supreme Commander why I thought that the plans were inadequate. He was quickly convinced and asked me what he should do—after all, the Invasion was less than two months away. I told him that he should send a request to the Air Staff for as high level a party as possible to be formed at the headquarters of the Allied Expeditionary Air Force, nominating Victor Tait, the Director General of Signals, to head the party. Then, almost certainly, Victor Tait would ask me to join him to provide the Intelligence, and I could then bring in those members of my staff who would best be able to help.

  Medhurst wrote to me later that same afternoon saying, ‘I hope that your talk with Tedder will bear fruit!’ It evidently did, for a few days later Tait rang me up to tell me that he did not know how it had come about but there had been a request from Supreme Headquarters for him to organize a party at A.E.A.F. to run the countermeasures against the German radar stations, and that he would like me to join him and do all the Intelligence work. We quickly formed our party, and started on a much enlarged plan of attack.

  One of my first steps was to visit Supreme Headquarters in Bushey Park to make contact with some of the Planning Staff. Among them was Major Manus, a Canadian, who greeted me with ‘Dr. Jones? Good God! I thought that you were dead!’ When I asked him why, he replied, ‘I gave orders for you to be shot!’ It turned out that he had previously been on the Planning Staff for the Dieppe Raid, and he had understood that I myself was going on the Raid. He had therefore detailed two men to guard me as far as possible but had also ordered them to shoot me if I were about to be captured by the Germans, because with my knowledge I was such a security risk. He told me that he had not been on the Raid himself, but that he had been waiting to meet the survivors as they landed and could find no trace of me, and he therefore thought it best not to make any further enquiries. This is the explanation underlying James Leasor’s book Green Beach, and also a legal action fought by Quentin Reynolds about someone going on the Dieppe Raid who was to be shot if in danger of capture.

  Green Beach is the story of Flight Sergeant Jack Nissenthal, who in fact did go on the Dieppe Raid as the expert ready to dismantle the German radar station at Pourville if it was captured during the Raid. This was in August 1942, some months after Bruneval, but it differed from the latter in being a very much larger Raid, and the radar was only a subsidiary target instead of being the main one. There was a suggestion that Flight Sergeant Cox should again go on the Dieppe Raid, but I advised him that I thought that he had already ‘done his bit’, and so another Flight Sergeant was selected from the volunteers. This was Nissenthal and somehow the order that would have applied to me had I gone on the Raid (and I have heard a story that there was a similar order regarding D. H. Priest, had he landed at Bruneval) was transferred to him. Actually there was no more reason for him to be shot than there would have been for Cox in the Bruneval Raid, since they knew comparable amounts about our own radar, and only as much about German radar as was necessary for dismantling captured equipment. It was the misapprehension of Major Manus regarding my own presence on the Raid that resulted in his dramatic orde
r. Full credit, though, to Nissenthal who had a very rough time indeed and survived his guards. He called on me immediately after the Raid and told me of his experiences. It had been a day of utter contrast—at one time quiet enough to be drinking wine with the local Frenchmen who thought that the Invasion had started and were therefore celebrating, and later coming under such heavy fire that, as he said, the Canadians built a parapet out of the dead bodies of their comrades, and fired their machine-guns over it. Nissenthal, who described the Canadians to me as ‘magnificent’, finally escaped by swimming a quarter of a mile out to one of the departing boats.

  For D-Day, it was important to know how much effort we should need to knock out a major radar installation, and so we decided to have a trial attack on one of the largest types of German equipment, known to us as a ‘Chimney’ because of the appearance of the large supporting column which held the array, and to the Germans as ‘Wassermann 3’. It was rather like a Hoarding turned with its long side vertical and mounted on a swivelling column, and had the advantage that it could determine height as well as range. Figures 26a and b show drawings of various types of radar station, one set being made by the Germans and the other by my own Section—in the case of the ‘Chimney’ it is hard to believe that there was no collusion between the two artists, but we had certainly not seen the German drawings, and it is very unlikely that they saw ours.

  Fig. 26a. German drawings of their principal types of radar equipment

  Fig. 26b. British sketches made without having seen the German drawings

  I decided on a ‘Chimney’ near Ostend, because our Belgian espionage network was excellent, and we briefed our agents about the date and time of attack, so that they could observe its effects. The attack took place on 16th March with rocket-firing Typhoons of No. 198 Squadron, and was very successful. Two attacks were made, and the turning mechanism was so damaged that the station had to be dismantled for repair. Our Belgian friends reported the results enthusiastically, and added that there was an exactly similar installation 23 kilometres or so along the coast, with the implication that they should like to watch us attack that, too. But once the technique had been established, we then held off until the campaign for D-Day should start in earnest.