by Hitler's Revenge Weapons- The Final Blitz of London (retail) (epub)
At 13.05 on 22 August a V1, rumoured to have been air launched, fell on the Danish island of Bornholm. It was with great courage and presence of mind that a group of Danes, led by Hasager Christiansen, beat the Wehrmacht to the site by some fifteen minutes, enabling them to photograph major parts of the airframe, the automatic pilot and compressed air spheres, and gather brief but near-accurate details of the inert bomb, which were then rushed to London. The Gestapo suspected the Danish officers Lieutenant Colonel Christiansen, Major Glyth and Colonel Nordentoft and there began a dangerous game of cat and mouse to avoid their arrest, incarceration or worse. Christiansen alone was caught and suffered grievously in German hands, but the details the group had gleaned gave the V1 a new priority, vis vis the V2, convincing the doubters that the flying bomb threat was real and imminent. Lord Cherwell, however, still demurred, claiming that the design was not technically sound and that, with only a 1,000lb warhead, it was no more than an expensive toy, posing no great threat to London. Time would tell.
Now you see it, now you don’t. Early sighting of an A4 (V2) rocket on Test Stand VII, at the north-east point of the Peenemünde Peninsula. (Medmenham Collection)
Vertical photograph of Test Stand XI, in the centre of the Peenemünde peninsula, used primarily for rocket engine tests. (Medmenham Collection)
The debate continued, with a paper circulated on 19 September 1943 outlining what was known to date, seeking the views of specialists on the technological feasibilities of the V2, and more specifically how it might be fuelled to achieve the ranges postulated. Responding to this on 11 October, the eminent scientist Isaac Lubbock, of the Asiatic Petroleum Company, supported by Colonel Post (Sandys’ scientific adviser), believed that the Germans might have come up with a practicable solution for feeding liquid fuel into the combustion chamber using a centrifugal pump, which could double the range of a rocket of comparable weight and warhead using solid fuel. The Projectile Development Establishment at Fort Halstead concurred, at a time when intelligence sources were suggested that 500 of the missiles might have been constructed already, and that a rocket offensive might begin as early as November 1943. Predictably, Lord Cherwell, and his scientific supporter, Dr A.D. Crow, refuted the claim, Cherwell assuring a high-level meeting in the Cabinet Room on 25 October that, if such a weapon did exist, it would be a year before it became operational, repeating that the ‘rocket like’ objects photographed at Peenemünde were most likely ‘some sort of kite balloon’ or an ‘outsize mortar’ and that the rocket postulated was no more than a ‘mare’s nest’, words he would come to regret.
One of the first PR photographs of an Fi 103 (V1) Flying Bomb, on the Baltic coast north-east of Flugplatz Peenemünde. (Medmenham Collection)
By the autumn of 1943 some fifty PR sorties had been mounted against Peenemünde itself, within a total Allied photographic coverage of 7,500 square miles of enemy territory, and the production of four million prints. Also, useful intelligence inputs from agents and partisans were increasing exponentially, especially in the west coast areas of France where a massive construction programme of V1 and V2 launch sites involved civilian and slave labour. It was on 28 September that the CIU reported what they thought was an underground V1/V2 launch site, at Marquise-Mimoyecques, again in the Pas-de-Calais, and well within the suspected range of the rockets – but they would be in for another unpleasant surprise (Chapter Nine).
It was no surprise when, in the wake of HYDRA, the Germans moved most of their V1 and V2 trials work to Blizna, beyond the effective range of Allied bombers, if not the PR aircraft, and built new production sites below ground where PR could not see them nor bombs reach them, leaving only the tunnel entrances and rail spurs visible and vulnerable. So it was that HUMINT from the Polish Underground and courageous workers producing the weapons became the primary source of information from such new locations as that in the Austrian Alps, south of Salzburg, the Thuringia mountains, Friedrichshafen, Dernau-Marienthal (near Bonn) and, above all, at Mittelwerk. One production unit which could be attacked, on good HUMINT from agents in Bern, Switzerland, and a Luftwaffe informant, was the Gerhard Fieseler factory at Bettenhausen, an eastern suburb of Kassel, where V1s were being produced, and on 22/23 October 1943, RAF bombers obliterated much of Kassel, severely delaying the production and final trials of vital components of the V1 for ‘three or four months’.
However, by far the most important production centre for both the V1 and V2, at Mittelwerk, lay deep underground in the Kohnstein mountains, just north of Nordhausen. Other than the tell-tale tunnel entrances and the rail lines leading to them, there was little evidence of the intensive activity in the labyrinth of corridors and caves underground where most of the missiles were being built. Intelligence sources were understandably limited to a few courageous agents and slave labourers working therein, who were either living and dying where they worked, or in little better conditions in the adjacent concentration camp at Mittelbau-Dora - with their replacements for them readily available from the notorious concentration camp at nearby Buchenwald.
In the autumn of 1943 the French Réseau AGIR Resistance Group, in which the French commercial traveller Michel Hollard was a major player with the ways and means of getting into Switzerland undetected, passed invaluable information to the British SIS, without the use of radio, giving the locations of six flying-bomb launch sites. The package showed standard site layouts, albeit adjusted to fit in with the local topography, giving details of ‘Maison R’ the non-magnetic building necessary for setting up the guidance system of the flying bomb, and a long, thin shed, with a blast-reducing curve at one end which would transpire to be storage facilities for V1s, without wings – this giving rise to the name ‘Bois Carré ski site’. With commendable reaction, a PR sortie was launched against one such site at Yvrench, to test the authenticity of this ‘scoop’. Sure enough, the photographs gave the necessary confirmation, together with additional information on what appeared to be mountings for a launch ramp, some 150 feet long, pointing at London. Where there was doubt before, there was none now: these were not rocket sites; they were clearly destined for flying bombs.
With the debate on whether and or how to anticipate German missile attacks continuing, an exasperated Churchill decreed that further discussion on scientific theory was pointless and appointed Sir Stafford Cripps, a senior left-wing politician in the coalition government and Minister of Aircraft Production in the War Cabinet, to carry out a full appreciation of the threats and their likely timings. At the inaugural meeting on 8 November1943 the senior PI at Medmenham, Douglas Kendall, updated information on the huge concrete structures at Watten and Wizernes, and at the following meeting R.V. Jones gave his estimates of the range, speed, height and accuracy of the flying bomb. From the abundance of evidence placed before him, Cripps had every reason to conclude that the V1s and V2s did exist and that multiple launch sites were being prepared for them in western France, but he did not think that such an offensive would begin before January 1944. There was no surprise when he recommended that full PR cover of the French sites continue, and that they be bombed whenever and wherever they were found. On 11 November the Chiefs of Staff decreed that Sandys should relinquish his role, and that the JIC should take the lead in evaluating all intelligence pertaining to the two missiles, but with Sandys continuing to sit on the committee and with some of his staff transferred to the JIC. The second Cripps report, dated 17 November, added little, other than revealing the discovery of a third, rather different, bunker being built under the hills at Mimoyecques, Pas de Calais.
Initially, the campaign to be waged against all aspects of the German long-range weapons threat was given the code name BODYLINE, renamed CROSSBOW on 15 November, with all associated targets known as ‘Noball’ targets, and the collection of intelligence, particularly by PR, an integral part. By the end of November ninety-six ’ski sites’ had been discovered, and they would be kept under continuous surveillance thereafter. The Crossbow Committee was formed on 29
December, and met first on 6 January, under the chairmanship of General Stephen Henry, of the New Developments Division; but still there appears to have been some uncertainty as to whether all these discoveries were valid targets or decoys. However, the evidence was strong enough to convince the realists of the imminence of rocket and flying-bomb attacks against London, and perhaps the invasion ports that, in December 1943, the RAF and USAAF were ordered to begin a strong offensive against the ski sites in France. This coincided with a report from a reliable agent in France, Jeannie Rousseau, that a V1 launch and support unit, Flak Regiment 155W, had arrived at Creil, north of Paris.
Flight Officer Constance Babington-Smith, who had been among the first to notice unusual activity at Peenemünde and its environs, was in the news again at the end of 1943 when she discovered, from archive photographs, what she thought was a tiny aircraft on a launching ramp in the sand dunes at the end of a road to the north of Peenemünde airfield and brought this to the attention of Douglas Kendall. Kendall immediately ordered a review of all previous photographs of the area, plus new cover, and his intuition paid off. On 28 November 1943 a midget aircraft was photographed in the same place by Squadron Leader Merrifield and Flying Officer Whalley, together with identical ramps at Zempin and Zinnowitz, farther along the Baltic coast to the east, which Babington-Smith found replicated and proliferating along the coast of north-west France.
Bletchley Park was also on the case, taking particular interest in SIGINT originating from units and radar tracking stations on the Baltic coast. Such words as ‘departure and impact’, ‘angle-shots’, ‘explosive trials’, and even repeated demands for soap, enabling identification of new units and the work they were undertaking. Decoded signals listing bearings, height and distances could surely mean only that missiles were being launched from Zempin. In November 1943, Bletchley had also intercepted a seemingly innocuous message from Greifswalder Oie which reported the death there of a Luftwaffe radar technician, Bergefreiter Wilde, apparently from suicide. The Ultra-wise heads at Bletchley Park wondered why an airman with his qualifications should be at Oie, which had not been of any military interest to them before, so they kept a listening watch on the frequencies being used, noting all the foibles and habits of the operators there as the message traffic increased in significance. Oie was, indeed, going to play a significant part in the rocket and flying-bomb trials to come.
The next few months were relatively and suspiciously quiet on the missile story, causing Section 3G(N) at Bletchley Park to redouble its efforts by introducing a keyword-alerting system, a complicated system understood by few, which looked into the roles of little-known units in the areas of interest. They included mundane administrative matters, such as stores requisitions, sick reports et al, but above all it was the increase in signals traffic between units deployed to the troop exercise area at Blizna which concentrated minds in the intelligence community. The Polish partisans around Blizna added much to these reports, noting that heavy plant moving into the area was believed to be associated with both the rocket and the flying bomb. One agent there found a heavily guarded rail flatbed near Blizna, carrying ‘an object which, though covered by a tarpaulin, bore every evidence of an aerial torpedo’, but another was more specific assessing the rocket to be some 12 to 14 metres long, about one metre in diameter and perhaps weighing 7 to 12 tons. Importantly, another confirmed that Experimental Battery 444 had been firing V2s at Blizna since November and, significantly in May 1944, came a report that a mobile artillery detachment, believed to be destined for Wizernes (France), had begun training there.
The Americans were now getting impatient for better information on the missiles, and Churchill’s Chief Military Assistant, General Ismay, directed that they be brought fully up-to-date on the potential missile threat, and the Crossbow Committee gave them the full story in January 1944. The Americans’ reaction was impressive, with the immediate construction of a full-scale replica of the ski sites found in France, for target evaluation and to assist their bomber crews with their forthcoming efforts to destroy them.
With the V1 ski sites now suffering severely from the CROSSBOW offensive, it was not surprising that alternative V1 launch sites were appearing, using mobile, pre-fabricated steel launch ramps, semi-camouflaged in harmony with the natural environment, in what would become known as ‘modified sites’, the first of these being photographed at Belhamelin, near Cherbourg on 26 April 1944. To further enhance security at these sites, German contractors were now replacing the French, thereby denying this source of intelligence from ‘embedded’ informants. These tactical sites would be supplied from large, underground storage facilities, such as those at the Nucourt limestone Caves, St-Leu-d’Esserent mushroom caves and the Rilly-la-Montagne rail tunnel. In April, General Eisenhower, the Allied supreme commander, allocated the highest priority to CROSSBOW targets.
Also in April came the first definitive information that the caves at Mittelwerk were producing V2s, when two Polish labourers at the Mittelbau-Dora Concentration Camp spotted a train carrying six rockets and as assortment of launch equipment from the underground plant.
Important discoveries were continuing to be made along the coastal areas of Western France, where a growing strip of ski sites had been identified, twenty miles deep and stretching 300 miles from the border with Belgium down to the Cherbourg peninsula, with some ramps clearly pointing at Bristol. In addition, inputs from the PRU, PIU, CIU and Bletchley Park all suggested that the existing rail system from Germany through France was already in use to deliver missiles to the Feldmulag (field munitions depots), eight of which would be found by PR within the next six months.
PoWs, slave labourers and free partisans in the resistance movements provided invaluable information on V1 and V2 activities; this sketch, with detail, smuggled out of Peenemünde in June 1942. (Medmenham Collection)
Armia Krajowa (AK), the Polish Home Army, deserves special recognition for its intelligence exploits in East Germany and occupied Poland. Indeed, this group of courageous men and women provided 42 per cent of all the HUMINT gathered from Central and Eastern Europe, including information from inside the Nazi concentration camps. In particular, a special group within the AK had been tasked to continually update information on the rockets and flying bombs being developed at Peenemünde, one of its members being a disgruntled, anti-Nazi Austrian NCO in the Wehmacht, Roman Traeger, who was stationed on Usedom. In Poland itself, it had not taken long for the AK to confirm that flying bombs and the rockets were being tested at Blizna, and thereafter it provided valuable reports from the launch site and from along the V2s’ flight path, as many of the rockets exploded in the air, shedding pieces along the route for the Resistance to collect and evaluate before the Germans arrived. Then, in May 1944, came their biggest coup of all, when a V2 crashed, with relatively little damage, close to the village of Sarnaki, on the River Bug, and was immersed below the surface of the water by the AK before the Germans could reach the area, and where it stayed until the partisans were able to disarm and dismantle it, ready for transport to Britain. On the night of 25/26 July, the pilot of a special, lightweight RAF Dakota made a covert, highly skilful landing and take-off at a disused German airfield near the site, to take the intelligence reports on the V2 prepared by the Polish aircraft designer Antoni Kocjan and significant parts of the rocket back to London. The package was also accompanied by Jerzy Chmielewski, who had many tales to tell as a witness to some of the firings in Poland. This very successful Operation WILDHORN (Operation MOST III, to the Poles), revealed valuable details on the construction of the weapon. The Poles also reported sightings of a complete V2, without its cover, in a railyard near Blizna and, most importantly, in June 1944, they discovered that liquid oxygen was part of the V2’s fuel mix. Meanwhile, on 31 July in France, a dummy V2 and Meillerwagen were captured intact in a storage area at Haut Mesnil, Hauts-de Seine. All the rocket’s secrets were now out.
That said, the Allies still needed to know when the V1 w
ould become ‘operational’, and an offensive against Britain begin. By the second week of May 1944 they knew that twenty-two of twenty-nine flights from the modified sites trials at Zempin had been deemed successful, despite three being lost on radar, two falling short and two overshooting. On 11 May one crashed at Brostrap, in neutral Sweden, creating a flurry of activity which led to two specialist RAF officers, Squadron Leaders Burder and Wilkinson, flying immediately to the scene (by BOAC Mosquito) to bring back all the information they could. It transpired that this was the third V1 to fall into Swedish hands, none of which carried live warheads, but the two RAF officers were able to bring back useful details on the small, pilotless aircraft, with its crude, pressed steel cylindrical fuselage and 16-foot plywood wings. Other than the absence of ailerons, the flight controls were conventional, operated by three gyroscopes, one of which was aligned to the compass. There was no radio control, guidance being pre-set, and the simple pulse jet ran on low-grade aviation fuel.
While many in the Allied intelligence community were attempting to predict when, where, and how the V1 offensive would take place, others were monitoring the development of the V2 rocket. On 22 May 1944 a German sergeant, a chemistry graduate and specialist in rocketry, who had recently completed a course at Peenemünde, was captured in Italy, and during his interrogation at Trent Park, was able to provide reliable information on the A3, its construction, fuel (ethyl alcohol and liquid oxygen), launch equipment and design range. He also produced useable drawings of the Bodenplatte base plate and the Meillerwagen transporter/erector, from which the rocket could be launched, but he was unable to say much about the warhead, other than it was not chemical. Professor ‘Bimbo’ Norman, the Ultra specialist at Bletchley Park, and Lieutenant Colonel Matthew Prior of MI14 in London were also busy getting and giving information on the V2 tests in Poland and over the Baltic, and were now aware that a very large army formation, perhaps at corps strength, was being established for the V2 operations in France, using simple launch sites, consisting of little more than concrete bases, often with natural cover and AA protection nearby.