by R. V. Jones
So what had we gained? A first-hand knowledge of the state of German radar technology, in the form in which it was almost certainly being applied in our principal objective, the German nightfighter control system. We now knew the extreme limits of wavelength to which the Würzburg could be tuned, and that it had no built-in counter either to jamming or to spurious reflectors; moreover it seemed that German radar operators were probably less able than our own. Besides giving us an estimate of the German rate of production and a knowledge of the German quality of design and engineering, it had provided us with the equivalent of a navigational ‘fix’ in confirming the ‘dead reckoning’ in our Intelligence voyage into the German defences.
It was, of course, a pleasure to write a report on the Intelligence aspects of the raid because it had gone so very well. In my report I included a map to show where Bruneval was, and added what I described as the track of a somewhat older and larger ‘raid’ in the hope of providing historical encouragement. It looked very like radar plots on an aircraft, and I actually had an officer ring me up and say ‘I didn’t know that we’d made that other raid—when did we do it?’ I then happily pointed out that if he would look at the beginning of the raid track, which started at Bosham he would see that it was timed as AD 1346 (Figure 10) and was in fact Edward III’s route to Crecy.
The raid had major repercussions both on the Germans and on ourselves. One minor objective during the raid was to demolish the villa adjacent to the Würzburg, because we imagined that it would be the local headquarters. In fact, it appeared to contain very little and it was left undamaged. We were therefore amazed to see, on aerial photographs taken a few days after the raid, that the Germans had demolished the villa themselves. They had concluded that it was the presence of the villa that had given the Würzburg away, and so they proceeded to remove it. Apart from shutting the stable door after the horse had gone, the action was ironic because it was the presence of the villa that very nearly caused us to overlook the Würzburg, and only Charles Frank’s astute observation saved us from thinking that the path from the Freyas had no other object than to go to the villa.
Another delicious consequence was that orders were issued that henceforth all German radar equipments were to be protected by barbed wire: since this soon shows up strongly on aerial photographs, because the grass grows longer underneath it or it catches rubbish blown by the wind, the enclosing circles of barbed wire enabled us to confirm several objects that we had previously suspected of being Würzburgs but where the photographs had been insufficiently clear (Plate 10(b)).
Fig. 10. The position of Bruneval, and the route of an older and larger raid. From Air Scientific Intelligence Report No. 15: The Intelligence Aspect of the Bruneval Raid, 13 July 1942
At the end of the war we came across German appreciations of the raid. They surmised that a new phase in the Hochfrequenzkrieg (‘high frequency war’) had begun, and that henceforward aggression of all forms could be expected against radar, including jamming and the dropping of spurious reflectors such as I had suggested in 1937 and which we were now developing. On the military side, the Germans expressed admiration for the discipline of our paratroops: ‘The Operation of the British commandos was well planned and was executed with great discipline. During the operation the British displayed exemplary discipline when under fire. Although attacked by German soldiers they concentrated entirely on their primary task’. And after the war Burck-hardt, the German Paratroop Commander, expressed the opinion that Bruneval was the best of all British raids during the war.
On our side, an unexpected bonus was the nervousness engendered regarding the situation of the Telecommunications Research Establishment at Swanage, where all our new radar development was undertaken. I had been pressing for the Establishment to be moved from Swanage ever since the Germans had occupied the Channel coast. Even if they did not invade, they had a good chance of hearing transmissions from our new types of radar sets under development, but Swanage was such a pleasant environment that the Establishment was reluctant to move, and I had no success in attempting to dislodge it.
However, the Bruneval raid made people speculate about the possibility that the Germans might plan a retaliation, and where better than on Swanage? Apprehension increased when we discovered that a German parachute company had moved into position near Cherbourg, although there was no indication of what its intentions were. The news of this move leaked down to T.R.E., and I saw my opportunity. I was due to visit the Establishment, anyway, to see how the investigation of the Bruneval equipment was going, and so Hugh Smith and I drove down to Swanage. We said nothing about the possibility of a German retaliation, but merely carried our tin hats everywhere and had revolvers ostentatiously strapped to our belts. We also contrived to give the impression of nervousness and an anxiety to get back to London as soon as possible. The next we heard was that T.R.E. was moving in a hurry to Malvern where, as the Royal Radar Establishment, it still is.
A further repercussion of the Raid stemmed from its success and a general feeling that echoed Cox’s comment when he first saw the Würzburg: ‘I found it to my surprise just like the photograph’. Apparently few other proposals for raids had had such clear objectives, with such effective prior Intelligence, and as a result I received a stream of calls from budding planning officers in Combined Operations who wished to make their mark by planning a successful raid. I forget how many radar stations were earmarked for raids in this way, although there was relatively little point in that we had found most of what we wanted to know at Bruneval. One proposal, however, did have repercussions which could have ended my career in M.I.6, as I shall tell later.
Decorations were awarded to some of those who took part in the raid, but hardly on the scale that its success merited. Frost and Charteris received the Military Cross, while Flight Sergeant Cox, Sergeant Grieve and Sergeant MacKenzie were awarded the Military Medal. Young was mentioned in Despatches, Company Sergeant Major Strachan (who had been badly wounded during the evacuation of the Würzburg equipment to the beach) was awarded the Croix de Guerre. I tried hard to have Cox awarded either the Distinguished Conduct Medal or the Distinguished Flying Medal; the latter would have been the Air equivalent of the Military Medal, and would have been more unusual for a radar mechanic, but protocol did not allow it.
I had no idea that I, too, was considered for a decoration, but evidently Archibald Sinclair must have made the proposal to Churchill for, after the war, the latter gave me a copy of his reply dated 3rd April 1942, which ran ‘Dr. Jones’s claims, in my mind, are not based upon the Bruneval raid, but upon the magnificent prescience and comprehension by which in 1940 he did far more to save us from disaster than many who are glittering with trinkets. The Bruneval raid merely emphasised and confirmed his earlier services. I propose to recommend him for a C.B.’
Lord Cherwell told me that when the Prime Minister’s proposal came before the Committee on Honours and Awards the head of the Civil Service, Sir Horace Wilson, ‘threatened to resign’ if I received a C.B., since I had been merely a Scientific Officer and I could not possibly have done work of such merit in my lowly position. The most that would have been justified would have been an M.B.E. or O.B.E. Finally a compromise was reached on a C.B.E.
Had I known this story I should probably have refused the decoration—in any event, Churchill’s minute was worth far more to me, and so was a reunion that occurred in December 1976 when, as part of a programme for Yorkshire Television, I met some of the few survivors of Bruneval (many were killed in later operations). Along with General Frost and Flight Sergeant Cox were Major Vernon, Sergeant Sharp and Private Dobson and another whose expert knowledge and unusual bravery I had hardly till then appreciated, Peter Nagel. He had come with his father to Britain from Germany before the war to escape the Nazis. Enlisting in the Pioneer Corps, he had volunteered as an interpreter. Even more than Cox, perhaps, he was in a specially dangerous position if captured, because the Germans would have had no mercy if they ha
d discovered his origin; but he went, as ‘Private Newman’, and without his coolheadness we might not have brought back the radar prisoner.
A month after Bruneval the great raid on the dock at St. Nazaire took place. Among those killed was my cousin Eric Beart, in command of Motor Launch No. 267 ‘A solicitor of about 30–35 or so, tall, fair and a most attractive personality. He had brought a rugger ball with him, hoping for a game on the quay while the commandos were about their business’ (C. E. Lucas Phillips, The Greatest Raid of All). Peter Nagel went on that raid, too, and was captured; fortunately his story was so convincing that the Germans never detected that he was not English. I was moved when after the Yorkshire TV programme such a gallant man should come quietly up to me and say ‘We would like you to know that if you had asked us we would have gone on another hundred raids’.
The success of the Bruneval raid clinched the future of paratroops in Britain, as Brigadier Alastair Pearson (who won four D.S.O.s in parachute operations) related at a dinner of the Scottish Territorial Battalion. The 1st Airborne Division and the 1st Parachute Brigade were immediately formed; and ‘Bruneval’ is the first battle honour inscribed on the drums of the Parachute Regiment.
CHAPTER TWENTY-EIGHT
The Baedeker Beams
ALTHOUGH WE were beginning to settle our scores with the German Air Signals Experimental Regiment, it was by no means defeated. By the summer of 1941 there were twenty beam stations on the Channel coast waiting to be directed against our cities, and it was therefore with considerable relief that we saw the Luftwaffe irretrievably committed in Russia. Moreover it gradually became clear that the Germans were going to be disappointed in their expectation that their Russian campaign would be over before the winter. I remember seeing a plaintive signal from a German commander saying that his transport was immobilized because the engine oil had frozen solid. Moreover, the Russians were showing technical ingenuity in defence. I noted that a German tank commander complained that his mine detectors would not work, because the Russians were using wooden mines. Hitherto, most anti-tank mines had been made of cast iron or steel, and the conventional way of detecting them was by the local changes that they produced in the Earth’s magnetic field. Even if non-magnetic metal were used, there were ways of detecting this also: but none of the standard methods would work against non-conducting materials such as plastic or wood, and it was therefore a very sensible thing for the Russians to use wooden cases which were both cheap and undetectable.
At one stage, however, the Germans tried to hoax us into thinking that they were coming back to bomb us, by sending a considerable number of false radio signals in a relatively simple code in the hope of making us think that a new Kampf Geschwader, KG11, had been formed and was occupying aerodromes in France and the Low Countries. The radio intercept operator who was listening on our side took down the signals, and sent them on to his headquarters—but with a note saying that in his opinion all the signals had been sent by a single man. It turned out that to an experienced listener the way an individual operator makes his Morse characters is as personal as his handwriting, and our radio operator had been alert enough to spot the attempt at radio forgery in this way. He was entirely vindicated a night or two later when the German spoof continued, and the spoofers got so mixed up that one had to send a signal to another saying that he was supposed to be an aircraft but was sending signals that should have come from a ground station. Actually, there would be so many clues obtainable from the prior arrangements for a genuine move back of the bomber force that I offered to give six weeks’ notice of any major new bombing threat to England.
As it turned out, six weeks was almost exactly the length of the warning that I was indeed able to give when the bombing threat reappeared in the shape of the ‘Baedeker’ raids on 23rd April 1942. This came from watching what our old opponents, KG100 and the German Air Signals Experimental Regiment, were doing. We found that on their practice grounds in Germany they were developing a new variant of the X-system, under the code name ‘Taub’ which means ‘deaf’. What they were attempting was one of the stratagems against which I had warned in 1940—that when the X-beams were jammed, they might well change the modulation frequency. In the new system they left the old modulation frequency on the transmission, so that we could continue to hear and jam it, but they superimposed a supersonic frequency above the limit of human hearing. If we failed to spot that, they could filter out our jamming and use the supersonic modulation to work a directional indicator in the aircraft by which they could fly along the beam.
The basic information came, as so often, from Enigma—not explicitly, of course, but there were various incidental clues which enabled us to put the foregoing picture together. I briefed Denys Felkin, and by good luck a prisoner appeared who had actually taken part in the supersonic trials. He had at times sat in the bomb-proof bunker near Märkisch Friedland from which the accuracy of bombing on the experimental range could be observed, but he showed a sturdy resistance to telling us anything about the trials. I well remember Felkin ringing me up and telling me that the prisoner would not give anything away, but that he might just ‘break’ if Felkin could persuade him that we knew so much already that there was no point in holding the rest back. ‘Can’t you give me anything?’ asked Felkin, and I said that I would look over what we knew and see whether we could pull something out of the bag. Charles Frank and I talked the problem over: one thing that we did know was the exact co-ordinates of the observation point. We therefore took the appropriate German map and imagined what the view might be from the observation point—hills, woods and roads—and we telephoned Felkin with the result. He then told the prisoner what he must have seen when he was watching the bombs fall, much to the astonishment of the prisoner who then said something like, ‘Well—if you have got hold of a traitor like that, there is no point in my trying to hide anything’, and promptly told Felkin what he knew.
We were therefore aware of every important detail of the new system many weeks before it came into effect, and No. 80 Wing was able to add supersonic modulation to its jammers in good time. The one condition that I laid down was that the supersonic jammers should not be switched on until after 80 Wing had heard the supersonic modulation of the German beams for themselves. Otherwise if we came up with the supersonic jamming before the Germans started to use supersonic beams, it would give them a very valuable clue regarding the source of our information. The Wing scrupulously obeyed my instructions, but we were puzzled to find that when the Baedeker raids started the 80 Wing observers could find no trace of supersonic modulation on the X-beams and yet KG100 seemed to operate unimpeded and successfully led the bomber force to its targets. Exeter, Bath, Norwich, York and Cowes were hit in succession between 23rd April and 4th May, with an average of about 50% of all bombs being on target. I could not believe that this was being achieved with the ordinary modulation of the X-beams, which was of course jammed, but 80 Wing insisted that no supersonic modulation was being used, and therefore they could not switch on the supersonic jamming. In the end we managed to prove that despite what the observers had said the Germans had been using supersonic modulation all the time, and an enquiry took place. Supersonic jamming was now employed, with dramatic results. The average percentage of bombs on target over the next month fell to 13%.
The enquiry revealed that despite all the detailed warning we had given, the designers of the listening receivers had overlooked the fact that supersonic reception involves a wider bandwidth than normal in the high frequency circuits of the receiver, and these circuits had not been suitably modified. As a result, the supersonic modulation was being cut out in the early stages of the receiver, and the operators had no chance of detecting it. Once again, an elementary mistake which should never have been made had cost many lives. This time I was so sickened that I did not even say that someone should be shot.
It is possible to estimate the number of casualties caused by the error, for the Official History shows that between 23rd
April and 4th May a total of 447 tons of bombs fell on the target cities. Had the countermeasures been as effective throughout this period as they were after 4th May, the tonnage on target would have been reduced by about 80% or about 360 tons. On the experience of the Coventry raid, 503 tons on target had killed 554 people and seriously injured 865. The 360 tons that fell on the early Baedeker targets and which would presumably have fallen on open country had our countermeasures been effective, thus killed about 400 people and seriously injured another 600. Fortunately our early warning had at least ensured that suitable jammers were in position, and so there was no delay in countering the supersonic beams once their existence had been proved, and this in itself must have saved many lives.
None of this story is in the Official History, which merely records that after 4th May, ‘almost everything went wrong for the attackers’.
