Authors: John Keegan
It was a recipe for leaks, all the more oddly given the reputation of the British as gossips and rule-breakers and of the Germans as humourless disciplinarians. Peenemünde clearly did leak, in a way that Bletchley, whose 10,000 initiates kept the secret intact for twenty-eight years, did not. It was leaks that alerted the British to the danger brewing at Peenemünde, first the Danish engineer’s report of careless talk in a Berlin restaurant, then in February 1943 another, mentioning Peenemünde, third, in March, serious authentication. On 22 March, two captured German generals, well known to the British as a result of their part in the desert battles against the Eighth Army, were brought together in a room wired for sound. They—Generals Cruewell and von Thoma—had not seen each other for several months. In the warmth of re-encounter, they began to talk—too freely. Von Thoma spoke of a visit to a test site where he had been told by the officer in charge of “huge rockets” which would go ten miles into the stratosphere and had unlimited range.
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A copy of the transcript of the Cruewell–von Thoma conversation was sent to R. V. Jones, head of scientific intelligence at the Air Ministry. He passed his concern up the chain of command, asking for authority to take charge of an investigation, the results not to be released, for fear of causing unnecessary alarm, until it was complete. When his proposal reached General Ismay, Chief of Staff to Winston Churchill in his capacity as Minister of Defence, a one-man ministry Churchill had created for himself, it was turned down. Ismay argued that a matter as important as a rocket attack on Britain must be taken out of the narrow scientific field and confided to a single investigator able to call on the widest advice. He was supported by the Chiefs of Staff, who accepted the gravity of the danger. “The fact,” Ismay wrote to Churchill on 15 April, “that five reports have been received since the end of 1942 indicates a foundation of fact even if details are inaccurate.”
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The Chiefs proposed that the single investigator should be Duncan Sandys, a son-in-law of Churchill who had been invalided out of the army’s only rocket regiment, an anti-aircraft unit, and, as a Member of Parliament, was currently serving as Parliamentary Secretary to the Ministry of Supply, responsible for weapons research. Churchill at once agreed—Sandys was a man of known ability and energy—and he started work on 20 April.
The previous day the Central Interpretation Unit (CIU), which examined photographic intelligence at Medmenham in Buckinghamshire, not far from Bletchley, had received orders from the Air Ministry to investigate signs of a German secret weapons programme wherever they could be found. The first area of search was to be in northwest France, since prognosis suggested that the likely weapons, a long-range gun, a rocket aircraft or “a rocket launched from a tube,” would have to be based within 130 miles of London. Duncan Sandys, displaying remarkable insight, wanted the search to be cast wider. He argued, on the basis of his experience with experimental anti-aircraft rockets, that any German weapons under development would have to be tested first, well away from populated areas, not in occupied territory and near the sea. Those limiting conditions suggested a site on Germany’s short coastline and as Peenemünde had already been mentioned in agents’ reports, it became the obvious target for close photographic reconnaissance.
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Peenemünde had been overflown by RAF photographic reconnaissance (PR) aircraft, but in the course of the general surveillance of enemy territory, not as a specific reconnaissance target. It now began to receive close attention; Peter Wegener was later to record in his memoir of Peenemünde the frequent passage overhead, in the beautiful Baltic summer months, of Mosquito aircraft. He accepted them uncomprehendingly as part of the scene and invested them with no menace; the skies of Germany in 1943 were full of British and American aircraft, but most were bound for Berlin.
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On 21 April, however, Peenemünde had been photographed carefully and many of its buildings identified, wrongly as would later appear. Photographed again on 14 May, and on 12 June, more mistaken identifications were made. Not until 23 June was the evidence interpreted to yield an identification of rockets. The photographic interpreters might be forgiven; what they had first described as “objects” were only 1H millimeters long on the film. There was also much to confuse them. Unknown to anyone in Britain, two, not one, revenge weapons were under development at Peenemünde, the flying bomb as well as the rocket; while in Britain the scientific defence establishment was riven by a bitter and highly personalised dispute between clever men, some of whom denied the possibility of the rocket’s existence.
THE REVENGE WEAPONS
Rockets of a primitive sort had existed for centuries and, in a form capable of reaching into space, had been imagined for over a hundred years. Pilotless aircraft, cruise missiles as they would be called today, had first been envisaged before the First World War, and in 1907 a French patent had been granted for a pulse-jet engine, exactly the power unit that was to drive the German flying bomb of 1944. What could be foreseen, however, was far from realisation. That was to wait until the early twentieth century. In 1926 an American, Robert Hutchings Goddard, launched the first liquid-propelled rocket, of modest capability. A contemporary, the Romanian-German Hermann Oberth, was meanwhile extending the theory of rocket propulsion, and though his work was written rather than practical, he greatly influenced a younger German, Wernher von Braun, who is universally recognised as the father of the extra-atmospheric rocket. Von Braun, by dint of single-minded enthusiasm, attracted the attention of another monomaniac, Walter Dornberger, who had succeeded in winning funds from the German army for rocket development. In the first flush of German re-armament, during the early Hitler years, von Braun and Dornberger began the German rocket programme and located it at Peenemünde. Von Braun supplied the brains, Dornberger the practicalities. An artillery officer of the Great War, he had subsequently trained as a scientist and had, in his university years, seen in rockets a means to evade the ban imposed by the Versailles treaty on Germany’s possession of heavy artillery. He had persuaded his superiors of the value of his idea, to such purpose that, starting in 1936, £25 million ($40 million in current values) was to be found from the German defence budget to pay for Peenemünde.
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Peenemünde began as an army establishment. The A-4 (V-2) and its predecessors were seen as equivalents of heavy guns and therefore to be commanded and operated by the army’s artillery branch. After the stunning victories over Poland, France, the Low Countries and, initially, Russia in 1939–41, Hitler and his generals lost interest in rockets. It was revived only by the inception of effective RAF attacks against German cities, beginning with the destruction of Lübeck in 1942. The Peenemünde budget was increased and the Luftwaffe, conscious that development of pilotless weapons most engaged the Führer’s favour, sought for one of its own, to match the army’s. The Argus firm was working on the design of a cheap and crude cruise missile; but the contract was eventually given to the firm of Fieseler, producer of light aircraft, notably the ubiquitous observation and liaison aircraft, the Fieseler
Storch
(Stork). The first model was flown at the end of 1942.
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The Fieseler flying bomb—historically the V-1, or flying bomb, but first known as the FZG-76 (FZG stood for
Flakzielgerät,
anti-aircraft target apparatus, a cover name); later, to British confusion, as the Fi. or Phi.103—was the simplest of aircraft. A cylinder, pointed at the nose, contained a ton of high explosive, detonated by an impact fuse. Two short wings were attached at the point of launch. At the rear, mounted above the tail assembly, was the tube for a pulse-jet, fuelled by low-grade petrol fed from an on-board tank. A shutter system caused the injected fuel to burn in regular bursts, giving the missile a speed over 400 mph, its characteristic and soon to be dreaded drone and a range of 150 to 200 miles; a simple cut-out device shut off the fuel at a selected point, leaving it to dive vertically to earth. It was launched either from a ramp (catapult, as the device was first described by the British), pushed by a reaction of hydrogen peroxide and permanganate; or, more rarely, air-launched from beneath a mother aircraft. It was reliable and cheap, costing about £150 in 1944 values.
Had it been given priority, and been mass-produced in large numbers during 1943, there is little doubt that the flying bomb would have caused terrible damage to London and other southern British cities; it might even have so disrupted shipping in British southern ports as to have set back or even prevented the launching of the cross-Channel invasion in June 1944. Initial plans, drawn up by LXV Army Corps, the formation created to operate it, were for the production of 1,400 bombs in January 1944; 3,200 by April; 4,000 by May; and a maximum of 8,000 by September. If achieved, and successfully delivered, London might have suffered the equivalent of a thousand-bomber raid every four days, far worse than anything inflicted on any German city even at the height of the strategic bombing offensive.
The production schedule was not to be met; but it might have been had not the A-4 (or V-2) programme diverted so much effort from the secret weapons effort in its totality. The A-4 was expensive (about £12,000 in 1944 values), where the V-1 was cheap; it was also complex, where the V-1 was simple. Even after a prototype had been successfully flown on 3 October 1942, only the fourth to have been tested, 65,000 separate modifications had to be carried out before reliable performance was achieved. There were setbacks of all sorts, including failures of the guidance system and disintegration of the rocket body itself; the most persistent fault, however, which took months to remedy, was explosion of the fuel. Some explosions took place soon after launch or actually on the launching stand, leaving evidence that could be fairly quickly assessed; most, however, occurred in flight, tens of miles down the test range, scattering debris far and wide or into the sea and causing von Braun and his team great difficulty in identifying the problem.
The real problem was that von Braun was attempting to design the prototype of all subsequent extra-atmospheric missiles, literally the direct ancestor of the moon rocket, which the A-4 was, while the Fieseler company, though the flying bomb was indeed also the ancestor of the modern cruise missile, was merely building a cheap, simple pilotless aircraft. The flying bomb was a potentially decisive weapon, which the A-4 certainly was not; even when perfected, it was too complex, too expensive and too difficult to mass-produce, and delivered too small a warhead to achieve a decisive result. Unfortunately for Germany, the A-4 engaged the Führer’s attention. As a result, instead of giving priority to the flying bomb, or ordering the V-1 and V-2 programmes to be conducted separately, he allowed them to proceed in tandem, and so to compete against each other. Competition was harmfully heightened by the separate interests of the army and the Luftwaffe, committed respectively to the V-2 and the V-1. Albert Speer, who correctly perceived that the V-2 drew wastefully on scarce resources needed for, among other things, Germany’s conventional aircraft-building programme, would have cut back or even closed down the V-2 programme; but to attempt to do so was to argue against the Führer and eventually against Himmler and his SS, who sought to gain control of the V-2 programme in pursuit of their goal of dominating the German war effort.
For over two years after the first successful test firing, work proceeded in secret, von Braun striving to perfect his brainchild, the British gradually becoming aware, through the receipt of scraps of information that eventually composed an intelligence picture, of the nature of the weapon that threatened them. It is not surprising that they were baffled for so long. The V-2 was a truly revolutionary weapon. It needed no elaborate launching system, as it was believed any long-range rocket would. It achieved stability without rotation, which was thought impossible in a long-range rocket. It had an on-board and autonomous guidance system, again thought an impossibility. Above all, it was liquid- not solid-fuelled, when conventional opinion held that only solid fuel could supply the necessary power; and it was single-stage, when convention again held that to achieve the transition from slow launch speed to high speed in ballistic trajectory two stages, or separate sections of the rocket, were essential.
The V-2, in its final form, was cylindrical, tapered at the tail, which mounted four fins, and sharply pointed at the nose. It stood 50 feet high, in its firing position, was six feet in diameter, and weighed 28,557 pounds, of which 1,630 pounds comprised the warhead of Amatol explosive and 9,565 pounds the fuel, 75 per cent ethyl alcohol in liquid oxygen. At launch, a turbine pump, driven by the decomposition of hydrogen peroxide, fed the fuel into the combustion chamber where it was ignited. Oxygen and alcohol were introduced separately, the alcohol also serving to cool the combustion chamber. There were two firing bursts. The first ignited to start the motor. When it was running smoothly, a second burst lifted the rocket off its platform. Guidance was supplied initially by four small graphite fins working inside the jet stream; later guidance was given by the four external fins. Both were controlled by gyroscopes which operated servo-motors to move their surfaces. Another device tilted the rocket into level flight when it had reached the correct altitude and yet another—originally a radio signal from the ground, later an on-board mechanism which measured velocity—cut off the motor at the point from which it had been predetermined its descent should begin. The missile eventually achieved four times the speed of sound and arrived on target—which could be only roughly predicted—without warning.
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Militarily, the deadliest feature of the V-2 was its launching platform, the Meillerwagen, so called after its manufacturer. The Meillerwagen was what today would be called a transporter-erector, a towed cradle which could elevate the V-2 into the vertical, placing a small conical platform under the nozzles of the jet-exhausts to receive the thrust. It was simple, efficient, inexpensive and, critically, inconspicuous, and was to bamboozle the British scientists engaged on the intelligence search for months. They believed at the outset that an extra-atmospheric rocket must either be rotated and fired from a massive tube, or multi-stage, requiring also a large, static base-platform; in either case they expected solid fuel to be the propellant, at least of the first stage if it proved multi-stage. Few admitted that it might use liquid fuel, which was thought suitable only for small, short-range rockets, and none at the outset conceived of anything like the Meillerwagen. Again, they might be forgiven. The Meillerwagen was, like the V-2 itself, a revolutionary concept; its descendants were to invest the intermediate-range missiles of the Cold War years, American and Soviet alike, with their strategic menace.