Most Secret War

by R. V. Jones

  The one other clue that I had spotted was that there seemed to be a convention that the director beams would generally be on frequencies between 66.5 and 71.5 and the cross beams between 71.5 and 75.0 Megacycles per second, the division being presumably due to operational convenience. Remembering that we needed to knock out the main and reserve director beams and at least one of the cross beams, I then made my mental gamble, and suggested a set of frequencies to Addison which he said he would adopt. All this took no more than five minutes on the telephone: but I was well aware that in these snap decisions I was probably gambling with hundreds of lives. Sobering though this thought was, the fact remained that someone had to do it, and I was easily in the best position.

  Because of the abruptness in his move to London, Charles Frank was staying with Vera and me, and I can recall driving back with him to Richmond and wondering, as we passed in bright moonlight through Roehampton, where the target really was. I for one did not know, and I do not think that anyone else did, either. Certainly I have no recollection of Coventry being mentioned in an Enigma message in the way that some accounts have stated; the teleprinter room into which the messages came was immediately across the corridor from my own, and no message mentioning Coventry was brought to me, as it certainly should have been if it had existed. As for any argument as to whether or not Coventry might have been forewarned, I knew nothing of it.

  The suggestion that Churchill was warned in the afternoon that the target was Coventry, and that he then had to decide whether the city should be warned or not, has been effectively disposed of in a review in The Times Literary Supplement for 28th May 1976 by Sir David Hunt, at one time his Secretary, drawing on evidence of Sir John Colville who was on duty at No. 10 Downing Street on the night in question. Churchill that afternoon had set out from London for Ditchley Park (the house a few miles north of Oxford which he used as a retreat in place of Chequers on moonlit nights) when he opened his box containing the latest Enigma decodes. A heavy raid was foreshadowed, and Churchill at once turned the car back to London. To those of us who knew him this could mean only one thing: he thought that the attack was to be on London and that his duty, in character with his lifelong inclination, was to be where the fight was hottest. This conclusion is borne out by Sir John Martin, who was with him as Secretary in the car, and by the fact that he sent Colville and Martin to take refuge in the deep air raid shelter at Down Street Underground Station, telling them that their young lives were valuable for Britain’s future, while he went up onto the Air Ministry roof.

  For myself, I spent a very uneasy night, wondering whether my gamble had been right, and switched on the wireless for the eight o’clock news, only to learn that a city in the Midlands had been heavily bombed. I forget whether the news mentioned Coventry at that stage, but it was evidence enough that the gamble had failed. There were 554 killed and 865 seriously injured. It would have been tremendous luck if I had in fact guessed the beam frequencies correctly, but I felt very miserable at having been instrumental in a negative way in contributing to the disaster.

  My wretchedness turned to bewilderment when, later in the day, the Enigma signals to the beam stations for the Coventry raid, target No. 53, were decoded. It turned out that, by luck, I had guessed the frequencies correctly. But in that case, where had the failure been?

  The answer came some days later when on 21st November Frank, Scott-Farnie, and I visited Addison in his headquarters at Radlett. By that time, the aircraft at Bridport had been salvaged, and the X-Gerät receiver had been taken to 80 Wing. There it was, full of sand and corrosion, with its dial covered up so that we could only see one number. I commented to Addison, ‘It’s a funny thing, but I have never known an “Anna” number to be above 85. Could your chaps get the cover off so that we can see whether it stops at 85 or goes up to 100?’ We had lunch, and when we returned there was the exposed dial: 85 was indeed the top number. This, of course, hardly increased our knowledge; but what did so was an investigation of the filters which were fitted to the receiver to let through the audible notes of the beams as the pilot listened in his headphones but to exclude any note that sounded differently. Moreover there was a course indicating meter which would tell the pilot whether he was to the right or left of the beam, and this was insensitive to any sound that did not get through the filters.

  In a commendably thorough examination which must have played its part in the later successes of our X-beam countermeasures, the Royal Aircraft Establishment at Farnborough found that the filter was tuned to two thousand cycles per second, a high-pitched note corresponding roughly to the top ‘C’ on a piano. Our jammers had been set not on this note but on one of fifteen hundred cycles per second, corresponding to the ‘G’ below top ‘C’. So the filter could distinguish between the true beam and our jamming, even though we had got the radio frequencies correct.

  It was one of those instances, of which I have since found many, where enormous trouble is taken to get the difficult parts right and then a slip-up occurs because of lack of attention to a seemingly trivial detail. Of all the measurements in connection with the German beams, easily the simplest was to determine the modulation note, because this could be done at any time in comfort; and yet whoever had done it had either been tone deaf or completely careless, and no one had ever thought of checking his measurements. I was so indignant that I said that whoever had made such an error ought to have been shot.

  My anger was increased by the prevarication I then encountered. The argument was that the Germans originally had their modulation on fifteen hundred cycles per second, which had been correctly measured, and they had changed their filters in order to avoid our jamming. But, if so, then we should have noticed the change in modulation of the German beams; and I finally managed to prove that KGr100 had had the same set of filters ever since the beginning of their operations. So that defence was untenable.

  What made things worse was that the countermeasures organization was already claiming successes in jamming the X-beams, when there was no evidence whatever of this either in the Enigma traffic or in failures of KGr100 to find its targets. This was the second time (the first being the 186 aircraft that we did not shoot down) I had to insist on facts because officers were kidding themselves. I have no doubt that had I been part of the countermeasures organization, instead of having an independent voice through Intelligence up to the Chief of Air Staff, my criticisms would have been suppressed.

  An alternative defence was that even if the jamming had been perfect, Kampf Gruppe would still have found Coventry because it was a bright moonlit night. Some nightflyers maintain this point, while others say that from eighteen thousand feet towns are only visible when seen against the moon, and so could not be attacked from the south by flying along the beam. One relevant fact is that on a later raid, when KGr100 attempted to bomb Derby on a similarly moonlit night (8th/9th May 1941) but when radio countermeasures were effective, the bombs intended for Derby fell on Nottingham, and those intended for Nottingham fell on open country.1

  After Coventry, the Germans mounted a similar large attack on Birmingham under the code-name ‘Regeschirm’. Since this was the German for umbrella, which was associated with Neville Chamberlain, who in turn was associated with Birmingham, someone at Bletchley correctly guessed the target. As foreshadowed, the Kampf Gruppe 100 target was No. 52, and it was attacked on 19th and 20th November. On the latter night, at least, Bletchley broke the target instructions some hours before the raid, but again our defences could achieve little. As I thought about the target during the night, the obvious thought occurred: first target No. 53, now 52—it left only target 51, Wolverhampton. At least we could be ready for that one.

  Officers at Anti-Aircraft Command who knew of my work had told me that if only I could give them twelve hours warning, as opposed to the two or three hours that at most were usually possible, they would move anti-aircraft guns to wherever I said. I therefore telephoned the Command and told them to move guns to Wolverhampton.
This was the day on which I was to visit Addison at Radlett, and so before leaving the Air Ministry, I made a point of seeing Sir Philip Joubert, one of the liveliest of Air Marshals, and told him why I thought Wolverhampton was ‘for it’. He reacted suitably, and the result was that our defences were braced as never before for a raid on a particular target. And then—nothing happened.

  Those whom I was myself criticising for their previous mistakes immediately seized their opportunity to turn the tables: I had alarmed and upset the defences of the whole country on a false deduction, and even some of my friends were not anxious to discuss the matter for the next week or so. And then I had an enthusiastic telephone call from Felkin, who said, ‘You know that you were saying that there was to be a big raid on Wolverhampton and that nothing happened. Well, we’ve overheard a conversation between two prisoners. One said he was in the Coventry raid and what a good show it was. The other said he was in the Birmingham raid. The first then said that there was to have been a similar raid on Wolverhampton under the code name “Einheitspreis”.’ Felkin explained that ‘Einheitspreis’ meant ‘unit price’, as at Woolworths, where most things cost sixpence, and this was the obvious link between the code word and the town.

  I do not know at which stage the attack was cancelled, but in a further check on security of the X-beam stations, it was stated that German photographic reconnaissance had shown that anti-aircraft batteries were installed in apparent anticipation of a large and already scheduled raid. And, in contrast to all the other 40 or so targets for which we had intercepted the beam instructions, target No. 51 was never attacked.

  CHAPTER NINETEEN

  Target No. 54

  TRAVIS AT Bletchley was very anxious that I should pay another visit to tell his staff about the use I was making of their information; and this, of course, I very readily agreed to do. Bletchley was divided into various ‘Huts’; and Hut 3, to whom I had spoken previously, was primarily concerned with taking the rawly decoded messages from the Enigma codebreakers, and passing them on, after classification, to whomever was entitled to see them. Norman, for example, had thus become in effect my agent in Hut 3. But there was some degree of feeling between the huts; in particular Hut 6, whose staff did the actual codebreaking, may have felt that Hut 3 was getting the kudos while Hut 6 was doing the hard work. And so on the morning of 28th November I drove down to Bletchley with Charles Frank and gave Hut 6 an account of what I had been doing.

  At lunch, I encountered Malcolm Saunders and some of my other friends in Hut 3 who were upset that I had been to Bletchley without Hut 6 letting them know. They therefore demanded that I should stay for the afternoon and lecture to them all over again. On the personal side, I could see trouble ahead, because I could certainly not get back to London before nightfall, and there was quite a chance that London would be raided that night, and Vera, already six months pregnant, would be left by herself. However, there was no doubt where duty lay: I was enormously indebted to Hut 3, as the whole country would have been had it known of the work that was being done, and I owed it to them to let them see how things were going. So we did not get away from Bletchley until about 4.30.

  Realizing that I would be driving against traffic streaming out of London in anticipation of the nightly air raid, I checked that my headlamps, which were feeble enough anyway with their wartime screens, were pointing well down so that I should not blind anybody coming the other way. The result was that I was repeatedly dazzled by the ill-adjusted lamps of oncoming cars. Finally, just where the A5 road narrows on the northern outskirts of St. Albans there was a particularly dazzling chain of vehicles coming northwards, and I could hardly see ahead at all. Suddenly I saw the rear wheels of a lorry in front of me, and braked hard. It was much too late and we crashed.

  The rear of the lorry, which should have been painted white, was so covered with mud that it was hardly visible, and the lorry had been left by its driver who, thinking that he might be running out of petrol although he still had some left, had gone off to find a supply. We were doing less than fifteen miles an hour, but there was so little time for braking that my own car was a complete wreck. Charles and I both went through the windscreen; he had a cut over his eye and I had one in the middle of my forehead, and all due to a driver who had panicked.

  Granted this disaster, we were then distinctly fortunate. We had crashed precisely outside St. Albans’ Hospital, and we walked into the casualty ward and were stitched up. We were then taken to the police station, where I telephoned Vera. The raid had in fact started before we crashed, but she was going to join neighbours downstairs. I remembered that my old pupil, Mark Meynell, was a curate in St. Albans’ Cathedral: he had two spare beds for the night, and so we stayed with him. I also knew that Winterbotham’s driver, Mrs. Yvonne Vereker, lived in St. Albans. She was able to pick us up in the morning and so we arrived in the office at the normal hour, bandaged and with pronounced headaches, but with no loss of working time.

  During the morning, Scott-Farnie told me that there was to be a conference at Fighter Command on the following day on the best way of making use of the beam information that I was providing, and that the Commander-in-Chief would be glad if I would attend. Scott-Farnie himself would be going and would have a staff car. He would route the car through Richmond to pick me up and he asked how he would find my flat. I told him that he should drive up Richmond Hill until he came to a large U-shaped block of flats, with a tennis court between the arms of the U. ‘You can’t miss it,’ I said, ‘because at the entrance there is a large clock at one end of the tennis court.’ And so we agreed to meet in the morning.

  Earlier in the week, on 25th November, Sir Hugh Dowding had been replaced as Commander-in-Chief at Fighter Command. Personally, I was sorry to see ‘Stuffy’ go. I had been with Lindemann and Watson-Watt when the press announcement was made, and Watson-Watt was quite pleased. I defended ‘Stuffy’ for his forthrightness (incidentally I knew that when Watson-Watt had offered him some hundreds of air-borne radar sets ‘Stuffy’ had said, ‘Give me ten that work!’). But Watson-Watt said that he had been unreceptive to new ideas. Most of the argument had been over whether Dowding was right in his method of intercepting German day raids on the way in. Leigh Mallory and Douglas Bader had advocated mass formations of fighters, which inevitably took time to assemble, and which could therefore only attack bombers on the way out, and they may have had the ear of those higher up. One further factor might have been the failure of Fighter Command by night. Certainly the new Commander-in-Chief, Sir Sholto Douglas, who as Deputy of Air Staff had known of my work, was concerned about the little use that so far seemed to have been made of my information, and it was for this reason that he had ordered a conference.

  It was going to be an interesting weekend. Besides the Fighter Command conference on the Saturday morning, we were to have Charles’ wife Maita, join us in Richmond.

  Maita had stayed in Salisbury because she was nervous about London, but she wanted to come for a sample weekend, and when would I recommend? No one was in a better position than I to give advice on this matter, and I suggested that she should come for the weekend beginning on 29th November, when there would be no moon, because the German Air Force was tending to concentrate its heavy attacks on moonlit nights; but that was before Coventry which, although it was of course a moonlit night, showed the Luftwaffe that they could now attack on dark nights, using KGr100 as pathfinders.

  Maita arrived in Richmond some time on the Friday afternoon, and Charles and I left the office about six o’clock, having now, of course, to travel by train since we had left the car wrecked in St. Albans. About twenty past six, while we were in the train, the sirens went, and we arrived home about twenty minutes later. Vera had dinner ready, and we sat down to soup. Bombs began to fall, and were getting alarmingly close; but knowing that we had a nervous visitor, we pretended that this was absolutely normal, even though we were on the top floor and the building was at times swaying so much that the soup was slopping
about in the bowls. And then we heard a noise that is unforgettable to anyone who has experienced it, sounding rather like ghosts in hollow chains rattling across the roof. Having once had an incendiary fall within three yards of me, I knew what it must be, and I went over to the back door of the flat, from which we used to admire the view across to Windsor Castle.

  The sight was fantastic—a panorama stretching far away to Kew Gardens, with all the domes, spires, and trees silhouetted in the pale blueish light from the ignited incendiaries which had been strewn everywhere, with here and there the orange glow of a fire that had already started. I recognized the handiwork of KGr100, and therefore what we were in for. I called the others to the door, saying, ‘Come quickly, this is a sight you may never see again!’ And then after a few spellbound seconds I said, ‘Now run downstairs like hell!’ We rushed down the darkened stairs, but we were not completely down to the ground floor when there was a tremendous noise, the building swayed violently backwards and forwards, and all the lights went out. We had been straddled by a stick of four 500 lb. bombs, two of which had fallen on the tennis court and burst in the garage underneath, demolishing the clock tower that I had told Scott-Farnie he couldn’t miss. The same evidently applied to the Luftwaffe.

  The first bomb had killed several people in a dug-out in the Earl Haig poppy factory across the road and the last bomb had missed us on the other side of the flat by no more than seven yards. Fortunately it had burst in soft earth, sending most of the explosive upwards. One of the two bombs in the tennis court must have come off somewhat early, otherwise it would have hit us directly. A curious feature of the explosions was that all the handles of the casement windows on one side of the building were bent back outwards through the adjacent panes, and these were the only panes lost.