Chapter 22: The Threat From Long-Range Weapons, (1939–1944)
(i)
SOON AFTER the outbreak of war in 1939 the British Naval Attaché in Oslo received an anonymous letter. His correspondent asked whether the British Government were interested in receiving a report on German technical developments. If they were they should, he suggested, signify their interest by causing a small change to be made in the preamble to our German news broadcast on a certain evening.
The offer was accepted; the change was made; and early in November the report arrived. It contained a wealth of information about German technical and scientific projects. Amongst other things, it told us that the Germans had two kinds of radar, that they were experimenting with gyroscopically stabilised rockets, and that they had an important experimental station at a place called Peenemünde, on the island of Usedom off the Baltic coast.1
The information covered so wide a field, and implied such an intimate knowledge of so many subjects, as to cast doubt on the good faith of our correspondent. It was argued that one man could not know so much unless he had been briefed to hoax us. The outcome showed, however, that much, at any rate, of the report was accurate. The existence of two kinds of German radar—known respectively as Freya and Würzburg—was confirmed by testimony not to be denied. In due course the sets were photographed, and in 1942 a Würzburg set was inspected and dismantled by a British radio-mechanic in the course of a daring raid on the coast of Normandy.* Again, the Oslo report said that the enemy was experimenting with remotely-controlled glider bombs.2 After nearly four years the Henschel 293, a
* The set—located at Bruneval, near Le Havre—was dismantled in the dark by Flight-Sergeant C. W. H. Cox, who volunteered for the task at a time when he had never been out of England either on the sea or in the air. He was parachuted into France. Among those who took part in the accompanying seaborne expedition was a civilian scientist, one of several who had asked to go. Vital parts of the equipment were brought back to England.
weapon conforming with that description, was used against our shipping. And these were not the sole examples of a prescience which caused a leading member of the Intelligence Branch of the Air Ministry to say later that ‘in the few dull moments of the war’ he used to turn to the Oslo report ‘to see what should be coming along next’.*
Of the rockets mentioned in the report, practically nothing more was heard in the United Kingdom for the next three years.3 Doubtless something further might have been discovered within that time if the matter had been thought sufficiently important; but, naturally enough, it received no great share of attention from our intelligence services while more urgent problems competed for their notice. The early history of the weapon will, therefore, be best studied through German eyes, before we turn to the awakening of our own knowledge of the threat which it presented.
(ii)4
German interest in large rockets as military weapons dates, for the present purpose, from about ten years after the end of the First World War. About that time the Ordnance Branch of the German Army conceived the hope that, by applying the national aptitude for research to a relatively novel field, they might not only overcome an immediate shortage of artillery created by the Treaty of Versailles but also help the Fatherland to steal a march over less far-sighted rivals. For example, should poison-gas be used again in war, rockets might provide a useful method of carrying it to its destination. According to Colonel Becker, head of the Ballistics and Munitions Section, even the rudimentary rockets which could have been used between 1914 and 1918 would have served that purpose better than the projectors then employed. At an early stage Becker recommended, therefore, that (besides relatively short-range anti-aircraft rockets) ‘long-range precision rockets’ should be developed ‘in the first place as gas weapons’.5 Another employment soon foreseen for the long-range rocket was bombardment of a distant target with high-explosive, as an alternative to bombing.6
Early in 1931 the Ordnance Branch secured the appointment of Captain Walter Dornberger, a thirty-five-year-old artillery officer whose training had included three years at the Technical High School in Berlin, to work on rocket development under a certain
* Quoted from a lecture delivered by Dr. R. V. Jones to the Royal United Service Institution on 19th February, 1947.
Captain Ritter von Horstig, who in turn was responsible to Becker.* A man of vision and a good organiser, Dornberger was well qualified to bridge the gap between the soldier and the scientist. Helped by a team of experts whose abilities he was quick to grasp, and who for the most part loyally supported him, he proved in the outcome capable of retaining—as probably no mere technician could have done—the confidence of his superiors through a period of exploration so protracted, and so beset by setbacks, as to call for a lively faith on the part of those who found funds for his efforts at the expense of other projects.
The field of discovery which awaited Horstig and Dornberger was not, however, altogether unexplored. Rockets had been used in war from very early times.† But in recent years the progress of artillery, and especially the increased accuracy conferred by the rifled barrel, had caused the rocket to fall into disfavour. Its development as a military weapon had been virtually at a standstill for more than a generation when, in the early part of the twentieth century, a Swedish officer named Unge patented a rotating rocket, or ‘aerial torpedo’, with a range of about 4,000 yards. Aimed solely by lateral and vertical adjustment of the tube from which it started on its course, Unge’s rocket achieved about one-third of the accuracy attainable at the same range with a light howitzer. The weapon was tested some five years before the First World War by German armament manufacturers, who discarded it in favour of ordinary mortars.
After the Armistice research on rockets was continued by various workers interested in such diverse applications as rescue of shipwrecked mariners, collection of meteorological data, delivery of mail across the Alps or the Atlantic, and travel to the moon.‡ Rocket-propulsion was also applied tentatively to wheeled vehicles and aircraft. German inventors were prominent in all these fields. In due course some of them were called in to help the Ordnance Branch. But up to the time when the German Army first turned its attention to the subject, no-one had produced a military rocket both powerful and controllable enough to compete seriously with orthodox artillery.
Where the long-range rocket was concerned—for anti-aircraft
* General Dornberger’s own account of the large rocket and its development is given in his book, V -2 (Eng. Ed. 1954).
† Missiles called by some translators ‘rocket-arrows’ are said to have been used by the Chinese against the Mongols in 1232. In Europe, short-range rockets were widely employed as siege weapons from about 1450 (and probably earlier), but those produced before the nineteenth century were mostly very unstable and inaccurate. The finned rocket introduced by William Congreve and used at Boulogne and Copenhagen in 1806 and 1807 (and in an improved form at Leipzig in 1813) was a great advance on its predecessors. Soon after the middle of the nineteenth century William Hale devised a rotating rocket with quite a good performance, but it was outmatched by the breech-loading rifled gun.
‡ For a popular account of some of this work, see Kenneth W. Gatland and Anthony M. Kunesch, Space Travel (1953).
rockets do not here concern us—the problems which immediately confronted the Ordnance Branch were first to find a sufficiently powerful method of propulsion, and secondly to achieve a steady flight. Attempts to bring the missile to its target—whether by careful aiming or by some form of remote control—were bound to be ineffective unless it could first be made at least as stable as a projectile fired from a mortar.
Among many factors affecting the first problem, the choice of propellant was not the least important. Briefly, the possibilities were black powder, as used by Unge; a more powerful solid fuel, such as cordite; and some kind of gaseous or liquid fuel. In a paper published in 1919 Robert H. Goddard, an American pioneer of high-altitude rockets, had suggested using hydrogen and oxygen;* he had since experimented with liquid fuels, and as early as 1926 had launched a rocket propelled by petrol and liquid oxygen.† The outcome of his later experiments was a paper on ‘Liquid Propellant Rocket Development’ which appeared in 1936. Inspired by Goddard’s first paper, and by other contributions to the theoretical literature of the subject, Herman Oberth, a Rumanian of Saxon origin living in Germany, had published in 1923 a technical treatise on inter-planetary rocket flight, in which the emphasis was laid on liquid fuels.‡ In association with Oberth, an engineer named Rudolf Nebel—besides others in Germany—had experimented with such fuels, assisted by a number of helpers amongst whom a young technician named Wernher von Braun was prominent.
As for stability, devices for promoting it included a tail-rod (as with fireworks); rotation of the entire rocket about its longitudinal axis (as used by Unge and Hale, and in his later years by Congreve); external stabilising surfaces, such as wings and fins; and internal gyroscopes. One of the chief difficulties was to prevent the missile from wobbling too much at the beginning of its flight, while it was still travelling slowly. A possible remedy was to launch it from a long projector which would keep it on a steady course until it had gathered speed; but this method raised fresh problems, which would grow more acute as the size and power of the missile were increased.
By the beginning of 1932 Becker could claim that experiments made in the last twelve months with rotating ‘black powder’ rockets had
* ‘A Method of Reaching Extreme Altitudes’ (Washington 1919).
† Still earlier experiments with liquid-propelled rockets are said to have been made by a Peruvian engineer, Pedro Paulet, between 1895 and 1897, and by the Swedish astronomer Birkland in 1905. Like other inventors whose claims to priority have been advanced in recent years, Unge considered the theoretical possibilities of liquid propulsion, but is not known to have tried it.
‡ In 1929 Oberth expanded his treatise (originally called Die Rakete zu den Planeträumen) and published the new version at Munich as a book of 431 pages, Wege Zur Raumschiffahrt. According to a well-informed source, it was this book which first roused the interest of the German Army in large rockets.
reached, and in some respects already passed, the stage where Unge had left off.7 On the other hand, development of a more powerful ‘liquid’ rocket with gyroscopic stabilisation was at a standstill for want of a suitable propulsion unit.8 In the meantime Dr. Heylandt, of the firm of that name, had produced a unit—employing petrol and liquid oxygen—which successfully propelled a motor-car at Tempelhof aerodrome.* But it consumed fuel too rapidly to be installed in a missile carrying a warhead of useful weight. Nebel’s group, though recently assisted by a subsidy, had also failed to solve the problem, despite some early success with small ‘liquid’ rockets. Accordingly Becker reported in January that ‘the only practical propellant at the moment is still black powder’.9 He added that rotation had proved the only reliable method of securing a steady flight with small and medium-sized rockets.
Nevertheless Dornberger retained his faith in the ‘liquid’ rocket as the missile of the future. He succeeded in persuading Becker to allow him to continue, and even extend, his work on liquid propellants and allied problems. In the course of the year he set a team of three technicians, consisting of Wernher von Braun from Nebel’s organisation and two of Heylandt’s former helpers (assisted by five mechanics) to study ‘liquid’ rockets at the artillery testing-ground at Kummersdorf; in addition one technician under his supervision continued work on ‘solid’ rockets in Berlin. Soon afterwards he succeeded in detaching himself from Horstig, whose attitude to ‘liquid’ rockets he later described as ‘negative’. Thereafter he quickly established himself as the army’s leading rocket expert. By 1936 his authority was unquestioned and his staff at Kummersdorf had grown to more than a hundred men.
The first big landmark in the development of the long-range rocket was reached in 1934. In December two liquid-propelled rockets with gyroscopic stabilisation were launched from the island of Borkum, off the North Sea coast, and reached a height of nearly one and a half miles. Fifteen months later General von Fritsch, Commander-in-Chief of the German Army, visited Dornberger’s establishment at Kummersdorf and was much impressed by what he saw. Thus encouraged, Dornberger embodied some of his ideas in a plan for a specific weapon, in the shape of a rocket designed to carry a one-ton warhead over a distance equal to more than twice the range of the ‘Paris Gun’ of the First World War. About the same time plans were made for the construction of a new research and development station for rockets and other novel missiles in a secluded but reasonably accessible situation at Peenemünde. The project was made possible by the co-operation of the Luftwaffe, whose leaders agreed to
* In earlier (and widely-publicised) experiments with rocket-propelled wheeled vehicles and aircraft 'solid’ rockets had been used.
contribute to the cost of the new site in return for the privilege of setting up their own experimental station alongside the army’s and of sharing certain facilities needed by both stations.
The rocket planned in 1936 was substantially that used against this country eight years later, and known as the A-4 or V-2. In the course of development the maximum range was increased from the original 172 miles to more than 200 miles.* Like its humble relative, the firework of commerce, the missile was launched and propelled by its own power, derived in this case from the combustion of alcohol, with liquid oxygen as oxidant. Each rocket consumed about four tons of alcohol and five tons of oxygen; in addition at least two tons of oxygen were lost by evaporation for each rocket launched. A subsidiary power-unit which pumped these liquids to the combustion-chamber utilised the reaction between hydrogen peroxide and a permanganate. Of these ancillary fuels relatively small quantities were used. A steady flight along the intended line of shoot was secured by a combination of external fins and a preset gyroscopic system which trimmed two sets of vanes placed respectively behind the fins and in the exhaust-stream.† Alternatively trimming during the early stages of the flight could be done by a radio beam, or Leitstrahl; but this method demanded topographical conditions not always attainable in practice. Remote control at later stages, though theoretically possible, was not attempted. Control of range depended on the termination of combustion at the precise moment when the rocket, under the influence of a device which progressively shifted the appropriate axis of the gyroscopic system, had reached the degree of tilt from the vertical, as well as the velocity, needed to take it to the target. These conditions were secured either by an appropriately-timed radio signal from the ground {Radio-Brenschluss), or by a preset integrating accelerometer (I-Gerät) carried in the missile. Except for its fins, the rocket looked not unlike a huge shell, some forty-six feet long and with an unusually sharp nose. Its all-up weight, complete with warhead and propellant, was nearly thirteen tons.‡
But in 1936 the A-4 was little more than an aspiration. As its name implied, it had a number of predecessors, including the two rockets—in fact belonging to the A-2 series, but commonly known as ‘Max und Moritz’—tested in 1934. In addition a small experimental model, the A -5, was used in relatively large numbers to provide working data during the long period of development which preceded the emergence of the final weapon. A minor success was achieved towards
* Experimental versions attained ranges of the order of 300 miles, but the normal maximum was between 200 and 220 miles. The warhead was originally to have contained a ton of explosive, but was reduced to a total weight of just under a ton, including about 1,650 pounds of explosive.
† This method was foreshadowed in a rocket launched by Professor Goddard in 1932.
‡ For further details see Appendix 43.
Plate 25. German Flying Bomb (FZG.76) immediately after Launching.
Plate 26. German Long-Range Rocket (A-4) in process of elevation to Firing Position.
the end of 1937, when two rockets larger than any previously tried, and belonging to the A-3 series, were launched from the Greifswalder Oie, a small island north of Usedom; but many technical problems, including that of control, were still a long way from solution. Dornberger and his assistants had shown that they could make large rockets leave the ground, and even fly some distance, but had yet to prove that they could bring the missiles to a given target.
In 1938 help was sought from the firm of Siemens, who soon devised a method of control more satisfactory than any previously put forward. After the outbreak of war assistance was obtained, too, from the schools and universities. Thereafter both the design of the combustion-chamber and methods of control were much improved as fresh minds were brought to bear on an increasing volume of experimental data.
In the spring of 1939 the Führer visited Kummersdorf and witnessed a combustion-test. The experience failed to convince him that the large rocket would soon become an important weapon. On a previous visit in 1933 he had been shown little or nothing of the ‘liquid’ rocket project.
By the spring of 1942 the A-4—eighty times as powerful as ‘Max und Moritz’—was at last somewhere near completion. Dornberger, who was in the habit of reporting progress at six-monthly intervals, took the opportunity to advance a tentative plan for the employment of the weapon. Drafted by one of his technicians, the scheme proposed the launching of 5,000 rockets a year at England from the coast of France by three field formations backed by a substantial fleet of tank wagons and special vehicles. The wide circulation given, on Dornberger’s authority, to the paper embodying the proposals displeased the German High Command, who ordered the recall of all but a few copies. Nevertheless the move served a useful purpose in bringing the matter to the attention of the Führer.
Trial launchings began at Peenemünde in early June. At first the old problem of control continued to give trouble. But on 3rd October the third rocket of the A-4 series to travel any appreciable distance crowned Dornberger’s hopes by flying perfectly along the intended course, reaching a height of more than fifty miles and a speed of roughly 3,300 miles an hour.* Some twelve years had elapsed since Dornberger began his task; nearly eight years since the success of ‘Max und Moritz’. The A-4 itself had been conceived six years before. The ‘long-range precision’ rocket foreshadowed in 1930 had been long in gestation, and when born had proved refractory. It seemed
* The distance covered is variously given in published and unpublished accounts as 120, 125, 167.5 and 170 miles. The first is almost certainly the correct figure.
that now, at last, the monster had come to heel, and that the hopes of more than a decade were on the verge of consummation.
Yet in the outcome nearly two more years went by before the rocket was judged ready for employment, even by men in urgent need of new devices to offset methods of air attack which were proving more terrible in the hands of their enemies than in their own. The delay had several causes. In the first place, formidable technical obstacles were met in the final stages of development. Early experiments with small ‘solid’ rockets had been hampered by prematurely exploding warheads; but the extent to which this trouble would dog the larger weapon was not foreseen. Secondly, a dense thicket of warring ambitions, muddle and mismanagement barred the way to the arrangements necessary for the manufacture and employment of the rocket in large numbers. Finally, a new factor came into play as the British Government gained tardy and uncertain knowledge of the German preparations.
By this time, too, the rocket had a flourishing rival in the shape of the FZG. 76 pilotless aircraft, or flying bomb, at one stage known as the Fieseler 103.*10 appearance roughly resembling a small fighter, the V-i, as it was afterwards called, was an expendable flying missile driven by a simple pulse-jet unit with a working life of half-an-hour to an hour. Each missile carried up to 150 gallons of low-octane aviation spirit. The flight was controlled by an automatic pilot monitored by a magnetic compass, and was terminated by an electromechanical device designed to bring the machine to earth when a predetermined distance had been covered. The warhead was roughly equivalent to that of the A-4. Unlike its competitor, which left the ground vertically under its own power, the flying-bomb was either shot from an inclined ramp by an ancillary launching device (Dampferzeuger) employing hydrogen peroxide and a permanganate, or (more rarely) released from a bomber aircraft modified to carry it. Again unlike the rocket, it was open to engagement by guns and fighters, though it was originally designed to reach a speed which fighters could not yet attain. On the other hand, it could be manufactured much more rapidly and cheaply than its rival.
Early in December 1942, Gerhard Fieseler, whose firm played an important part in the development of the flying bomb, launched an unpowered prototype from a Focke-Wulf 200 aircraft over Peenemünde. On the 24th of the same month the first ground-launched flying bomb was fired from a ramp there and satisfied the conditions of the test by flying about 3,000 yards. Tested for range and accuracy some months later, after some fifty practice launchings had been
* The term Flakzielgerät (anti-aircraft artillery target apparatus)—not Fernzielgerät (long-distance target apparatus), as has been commonly supposed—was adopted to conceal the true nature of the weapon. Hence the abbreviation FZG.
completed, the missile flew more than 150 miles and gave a somewhat flattering impression of its capabilities at the stage then reached by finishing little more than half-a-mile wide of the aiming-point. The final stages of development were, however, marred by technical shortcomings, some of which persisted after the weapon had gone into active service.*
In 1943 Hitler’s attitude to long-range weapons underwent marked changes, dictated largely by his increasing need of an answer to Allied bombing. About five months after the successful trial of the A-4 at Peenemünde he dreamed that the missile would never reach England, and his newly-kindled interest in it was temporarily eclipsed. In any case a rocket designed in 1936, and carrying a modest one-ton warhead, seemed a doubtful substitute for the weapon of annihilation—delivering, say, ten tons of explosive—which his imagination pictured. A detailed verbal report by Dornberger and a lecture by Wernher von Braun, illustrated by a film of the October launching, played a big and probably decisive part in persuading him that nevertheless the project was well worth pursuing. According to Dornberger himself, at the end of the interview the Fuhrer apologised for his previous scepticism, declaring that ‘if we had had the A-4 earlier and in sufficient quantities, it would have had decisive importance in the war’. Afterwards he ordered that a diploma conferring the title of professor on the lecturer should be prepared for his signature and presented to von Braun by Albert Speer, Reichsminister for Armaments and War Production. On 25th July he signed a document decreeing that ‘the successful prosecution of the war against England requires the maximum output of A-4 weapons in the shortest time’, and authorising Speer to ‘draw on the resources of all branches of the Armed Forces to their fullest extent as well as on the resources of the whole of the industrial war economy’.11
Meanwhile, at Hitler’s instigation, a newly-appointed Long Range Bombardment Commission had done their best to weigh the relative merits of the rocket and the flying bomb. After visiting the army and air force establishments at Peenemünde, where they were well entertained, the commissioners recommended that effect should be given to both projects.12 Plans were made to manufacture both missiles in substantial numbers and train men to use them. Sites for launching-points and stores in Northern France were reconnoitred and constructional work was put in hand. The structures planned included a small number of concrete ‘bunkers’ from which rockets could be launched immediately after servicing, to supplement those launched by mobile troops from simple platforms. By the summer a start had been made in nearly all these fields, though the missiles themselves
* For a further account of the flying bomb and its development, see Chapters 23 and 24.
were still manifestly imperfect. If German hopes were realised, a heavy bombardment of the United Kingdom with both rockets and flying bombs would begin towards the end of 1943 or early in 1944.
(iii)
On the British side, scarcely anything was known of all this until 1943 was well advanced. Towards the end of 1942, however, an agent whose reliability was still untested—but who later showed himself trustworthy and well informed—had sent in the first of three reports which together indicated that trials of a long-range rocket had been held recently near Swinemünde.13 In the early part of 1943 reports from other informants linked such trials more precisely with Peenemünde. As we have seen, the experimental station there had been mentioned in the Oslo report as long ago as 1939. The place had been photographed by a reconnaissance aircraft in the spring of 1942, when ‘heavy constructional work’ was seen to be in progress. In April, 1943, the photographs taken on that occasion and on three more recent visits were reviewed in the light of the latest information from other sources. They revealed nothing which looked like decisive evidence of experiments with long-range rockets. On the other hand, support for the belief that the Germans were experimenting with unusual missiles—perhaps of several kinds—was obtained from prisoners of war, and especially from one officer of high rank who was unwittingly indiscreet.14
Unfortunately nothing like a clear picture of the weapon or weapons which the Germans were said to be developing emerged from the information collected by the early spring. In connection with rockets, ranges up to 130 miles had been suggested, and a warhead containing five. tons of explosive had been mentioned, as had one containing ten.15 But these estimates—in any case misleading—came in a context which made assessment of their accuracy anything but easy. On the other hand, even without the Oslo report—whose foreshadowing of the Henschel 293 had not yet been justified by the appearance of that weapon—the evidence received in the last few months did suggest quite strongly that the enemy was experimenting at Peenemünde with novel missiles, including one which could fairly be called a long-range rocket.
The task of collating and considering this evidence fell in the first place on the intelligence staffs of the fighting services. At the Air Ministry it fell particularly on the officer appointed for the express purpose of dealing from the viewpoint of a physicist with such matters. This was Dr. R. V. Jones, who had earned a high reputation as a student of enemy methods and technical equipment by his work on
German navigational beams in 1940 and by his insistence that his findings on that occasion should not be overlooked.*
To Dr. Jones and his colleagues at the Air Ministry their duty in the circumstances which had now arisen seemed clear enough. On the assumption that the long-range rocket did exist, they must find out more about it, and thus put themselves in a position to assess the threat that it presented, before giving the alarm to those potentially concerned with counter-measures.16 Unless the weapon proved a myth, the operational staffs would have to be told about it in due course; meanwhile agents must be briefed to fill gaps in our knowledge, prisoners of war must be pressed to tell us what they knew, and the photographic reconnaissance organisation must be asked to keep watch on Peenemünde and on any other place which might come under suspicion.
Their counterparts at the War Office took a different, but equally legitimate, view of their responsibilities. Conceiving that the reports already received from a variety of sources pointed to a danger so grave that knowledge of it ought not to be confined to the intelligence staffs, they placed the matter before the Vice-Chief of the Imperial General Staff, Lieutenant-General A. E. Nye.
General Nye consulted Professor C. D. Ellis and Dr. A. D. Crow, respectively Scientific Adviser to the Army Council and Director and Controller of Projectile Development in the Ministry of Supply, with a view to obtaining, amongst other advice, their opinion as to the feasibility of the project imputed to the enemy. On 11th April a paper on ‘German Long Range Rocket Development’ was circulated, on General Nye’s authority to his colleagues and their immediate superiors, the Chiefs of Staff.17 Its avowed aims were to draw attention to the reports of experiments with long-range rockets which had been received since the previous December, to give some account of the potentialities of such a weapon and to suggest counter-measures. Perhaps unfortunately, the paper also drew a speculative picture of the rocket. An annex gave the general trend of the reports received in the last few months, but added that ‘technical opinion’ envisaged a missile ninety-five feet long and weighing about nine-and-a-half tons, launched (‘unless an extremely accurate method of directional control in flight has in fact been developed’) from a projector about a hundred yards in length. The weight of the warhead was put at one-and-a-quarter tons, including rather less than one ton of explosive. These figures appear to have been based on the assumption that a solid propellant would be employed, but that assumption was not stated.
In the body of the paper General Nye recommended that plans
* See pp. 157-158.
should be made for the detection by air reconnaissance of the hypothetical projectors, and for their destruction at short notice by air attack. He also suggested that Royal Observer Corps posts and Royal Artillery flash-spotting stations in the south-eastern counties should be told to watch for signs of ranging shots, and that the Ministry of Home Security, and also the Prime Minister in his capacity as Minister of Defence, should be warned that large rockets might descend on the country with little or no warning.
The Vice-Chiefs of Staff considered these recommendations on 12th April. They agreed that the Prime Minister and the Minister of Home Security should be warned, and that further consideration should be given, at the next meeting of the Vice-Chiefs on the 15th, to ‘the scientific investigations to be put in hand.18 Before that day arrived the War Cabinet Secretariat were able to report that the question of the further investigations to be undertaken had been examined. This report was accompanied by the suggestion that it might be thought proper to associate with the work a variety of authorities in addition to the Intelligence Branch of the War Office, the Scientific Adviser to the Army Council and Dr. Crow, and by the further suggestion that ‘in view of the importance of the subject, the Vice-Chiefs might care to consider recommending to the Prime Minister that one individual, who could devote a considerable amount of time to the matter, should be appointed to take charge of the investigations so as to ensure that no aspect is overlooked and that the work is pressed on with all speed.19 Chiefs of Staff welcomed the proposal that one man, who could give time to the work, should head the investigation. On their recommendation the task was entrusted to Mr. Duncan Sandys, Joint Parliamentary Secretary to the Ministry of Supply.
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The position thus created was unusual and led to some misunderstanding. It was argued at the time and afterwards that, if the object of the investigation was to establish more or less precisely what the enemy was doing, the best co-ordinator would have been an intelligence officer who either was himself a trained scientist, or had a trained scientist experienced in the evaluation of intelligence reports at his right hand.20 Not unreasonably, it was claimed that an investigator accustomed to found his conclusions on evidence from the enemy’s camp would be more likely—precisely because his outlook was more limited—to establish the nature of the new weapon than someone used to working in a wider field and therefore more apt to be influenced by the views of British experts as to what was feasible.
On the other hand it is clearer, perhaps, to-day than it was to many at the time that the assumption underlying these arguments was not necessarily valid. If the purpose in view was not so much to discover what the rocket was like as to find out whether it existed and, if it existed, to take immediate steps to counter the worst threat that it might present, then there was a good case for the appointment of a co-ordinator with the broad outlook and wide powers of a minister.
Mr. Sandys had no doubt that to satisfy himself of the existence of the rocket and, having so satisfied himself, to ensure that counter-measures were not neglected, were far more urgent tasks than discovery of the precise nature and performance of the weapon.21 At the same time it seems certain that his task would have been easier if more had been known about the rocket in the early stages. As Mr. Sandys discovered, it was sometimes difficult to persuade all those with whom he had to deal to assent to energetic and far-reaching measures of defence against a threat of which they could be given only vague and at times exceedingly misleading notions.
His first report was drawn up on 14th May 1943, some three or four weeks after his appointment.22 By this time he felt sure enough of the existence of the rocket to make a number of recommendations for counter-measures, all of which ultimately bore fruit. Believing that he had now reached a stage where he must make some attempt to answer questions about the probable dimensions and performance of the weapon, he also put forward—with reservations prompted by the inconclusive and conflicting nature of the evidence from Germany—the tentative conclusion, based on a combination of evidence from prisoners of war and scientific calculations, that the missile might be a multi-stage rocket twenty feet long and ten feet in diameter, with a total weight of seventy tons and employing a new and unspecified propellant to carry a warhead weighing up to ten tons over a distance of a hundred to a hundred and fifty miles. Launching from projectors (now described as not necessarily very large or conspicuous) was again assumed, and was indeed suggested by the testimony of a number of informants, some of whom would seem in the light of after-knowledge to have been thinking of weapons distinct from the A-4 rocket.
No one reading this report could doubt that, if the rocket was indeed so massive as was suggested by these figures, the effects of a prolonged bombardment with it were likely to be very serious. On a night in February 1941, a two-and-a-half ton bomb, falling on a London suburb, had killed eighty people. On that basis the Ministry of Home Security calculated that a rocket with a ten-ton warhead might kill six hundred. A further estimate showed that, if one such missile fell in the London area every hour for thirty days, the cumulative casualties might, in theory, amount to 108,000 killed and as many
seriously injured.23 In practice the overlapping of one crater with another, and removal of part of the population to safer areas, might be expected to reduce these figures very considerably. But even when all allowances were made, a month’s bombardment at that rate seemed likely to cause casualties at least five times as great as those suffered in September 1940. Damage to property was also likely to be very heavy. Thus for Mr. Herbert Morrison, Home Secretary and Minister of Home Security, and indeed for every member of the Government, the new estimate of the rocket’s mass raised momentous issues.
The first good evidence regarding the dimensions of the weapon was received in June, when objects which appeared to be rockets—as indeed they were—were revealed by photographic reconnaissance at Peenemünde.24 They seemed to be about thirty-eight feet long and seven feet in diameter; but nothing was known of their mass or capacity for destruction, except what could be gleaned from informants who put the weight of the warhead at anything from ten tons to a quarter of a ton or less, and from a prisoner of war who thought the rocket might weigh sixty tons, but some of whose notions were obviously far-fetched. Another prisoner claimed to have seen—and probably had seen—a relatively small experimental rocket launched some years before, and believed that the propellant used was pure alcohol. A weight of sixty to a hundred tons, including a warhead containing from two to eight tons of explosive, did, however, seem consistent with the apparent dimensions of the objects photographed, though the relevant calculations were misleading inasmuch as they rested on ignorance of the means by which the missile was propelled.
Accordingly these last figures were given in the third of the interim reports presented by Mr. Sandys.25 The report was circulated on 28th June. Meanwhile the presence at Peenemünde of substantial ‘test stands’ and other lofty buildings had brought back the old belief in large and probably conspicuous projectors. In view of that belief and of the huge mass attributed to the rocket—which in fact was light enough before fuelling to be transportable by road, and could be launched from simple platforms made of concrete or rough wooden sleepers—some hope was entertained that projectors intended for launching rockets against this country might be found in likely situations near railways. One possible projector had been spotted near Cap Gris Nez.
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From the standpoint of the present it is clear that these attempts to draw conclusions (however tentative) about the weight of the rocket and its warhead, to say nothing of the method of launching, were invalidated by lack of evidence regarding the fuel employed, and also to some extent by failure to estimate correctly the dimensions of the
objects photographed at Peenemünde. The prisoner of war who thought that the fuel was alcohol had the root of the matter in him; but possibly he was unaware of the crucial fact that the oxidant was liquid oxygen. In any case there was no reason to regard his testimony as more conclusive than that of others. In the absence of a convincing lead from Intelligence, the prevailing tendency among British experts invited to consider the problem was to assume that the fuel was cordite, though the chance that the enemy had developed a novel fuel of unrivalled potency was not ruled out.
Not surprisingly, a picture in which so much was left vague, or was admittedly based on little more than guesswork, was not everywhere accepted without scepticism even at the time. Moreover, scepticism seemed all the more justified since the whole conception suggested by that picture was not entirely convincing. A rocket weighing sixty tons, which would be difficult to handle and apparently was intended for launching from large projectors scarcely likely to escape our notice, was not, some thought, a weapon to which the Germans would be very likely to devote their energies, even if they could be assumed capable of overcoming, by means unknown to us, the many technical problems inherent in the design and construction of so vast a missile.
The report circulated by Mr. Sandys on 28th June was considered next day by the Defence Committee (Operations). Mr. Sandys, believing that the rocket presented a threat which the Government ought not to ignore, advocated (among other measures) a heavy air attack on Peenemünde as soon as the nights were long enough. Lord Cherwell, who spoke with the authority not only of a minister but also of Scientific Adviser to Mr. Churchill, put the case for scepticism. He drew attention to the difficulty of believing that the Germans would genuinely devote time and effort to a weapon so unwieldy—and so hard to reconcile with current views of the possible—as the rocket was at that time thought to be. The whole story seemed to him to bear the marks of an elaborate cover-plan, designed to conceal some genuine development—possibly a flying bomb. The presence at Peenemünde of unconcealed and uncamouflaged objects purporting to be rockets he regarded as strong support for that interpretation. On the other hand Mr. Sandys pointed out that Peenemünde was undoubtedly a very valuable station, and that a hoax whose most probable result was to bring down a heavy attack on it would be an absurdity. Invited by the Prime Minister to give his views, Dr. Jones confirmed that the place was one of the two most important experimental establishments that the Germans possessed, and gave his support to the inference drawn by Mr. Sandys. He believed in the existence of the rocket—in his opinion the case for it was rather stronger than his case for the German radio beams had been in 1940
—but was not prepared to say when the enemy would be ready to use it against this country.
After further discussion the committee decided in favour of the attack on Peenemünde and of the other counter-measures which Mr. Sandys had recommended. They agreed that his work and that of a number of committees established under his aegis to consider various problems arising from the threat of rocket-attack should be pressed forward. In view of the suggestion that preoccupation with the rocket—whether it was spurious or not—might divert attention from other German projects, and also of recent information which included a report from a well-placed source that ‘the secret weapon to be used against London’ was ‘an air mine with wings, long-distance steering and a rocket drive’, and was launched by catapult, they further agreed that Mr. Sandys should look into the question of jet-propulsion as applied by the enemy to aircraft, whether piloted or pilotless, and that Dr. Jones should be closely associated with that aspect of his enquiries.
Measures which flowed from these decisions included the installation at five C.H. stations between Dover and Ventnor of ancillary equipment which (it was hoped) would enable them to detect the rise of rockets and determine the approximate location of their launching-points; and a scheme to prevent the enemy—by means of smoke-screens, simulated rocket-bursts, a confidential notice to the Press and censorship of posts and telegraphs—from assessing the accuracy and effectiveness of his bombardment. By the early autumn plans were ready for the removal to safer areas of 100,000 Londoners and 20,000 residents of Portsmouth, Gosport and Southampton.27 Reserves of Morrison shelters were accumulated in the London area and near Portsmouth and Southampton; provisional plans were made to inform the public that rocket-attacks might be expected; and a system was devised which might, in favourable circumstances, enable the air defence authorities at Stanmore to give a brief warning that a rocket was on its way.
The attack on Peenemünde was made by Bomber Command on the night of 17th August. It proved outstandingly successful, though expensive. Five hundred and ninety-seven aircraft were despatched and forty failed to return. Considerable damage was done to buildings, and 735 people were killed, including some highly-placed technicians.* The effects of the raid could not be fully gauged at the time, though they were known to be substantial. In any case its execution was a source of keen satisfaction to Mr. Sandys, who had thus persuaded the Government to take the rocket seriously in face of Lord Cherwell’s criticisms and in spite of manifest gaps in our knowledge of the weapon.
* Dornberger, op. cit., Chapter 15.
After the raid a plan—in any case unsatisfactory in many ways—which the Germans had made for the large-scale assembly of rockets in three factories at Peenemünde, Friedrichschafen and Wiener Neustadt was abandoned. Under the new scheme which replaced it, final assembly—and ultimately also the manufacture of most components—was done solely in an underground factory at Niedersachswerfen, in the Harz mountains near Nordhausen. Production at Niedersachswerfen began in January 1944. The attack on Peenemünde was followed, too, by orders from the Führer that henceforth at least the majority of launching trials must be conducted further east, in an area safe from air attack. Political motives would seem to have been largely responsible for the choice of a site at Blizna, in Galicia, previously requisitioned as a training camp by the S.S.—a body which had sought since the spring to gain control of the rocket undertaking and which already exercised powers of general supervision over the factory at Niedersachswerfen. Here the first trials ever made of the A-4 rocket with live warheads against targets on land revealed such a high proportion of premature bursts that production soon had to be suspended while Dornberger and his assistants strove desperately to put the matter right.* After many experiments a packing of glass-wool between the fuel tanks and the outer skin was found to reduce the proportion of premature bursts to less than one-third. Ultimately the trouble was traced, not to the heat-transference which the packing was intended to prevent, but to a structural weakness which could be cured by reinforcing the front of the hull with a steel casing. Provided that a relatively insensitive fuse was fitted, premature disintegration of the rocket did not, however, necessarily imply premature detonation of the warhead, which frequently flew on alone towards the target. At the cost of reducing the destructiveness of the weapon, Dornberger therefore reluctantly accepted a less sensitive fuse than he would otherwise have used.
By the autumn of 1943 the failure of the original production programme, the attack on Peenemünde and the fortuitous destruction in a raid on Hamburg of a factory which made special vehicles for launching-troops had extinguished the prospect that the weapon might go into service early in 1944. For some time Dornberger believed that active operations might still be possible in the spring; but eventually his hopes were dashed by the trouble with premature bursts. Meanwhile, at the beginning of September 1943, his functions had been defined by his appointment to two distinct posts in connection with the rocket. As Special Commissioner (Army) he was
* According to a German official report, 57 attempts to launch rockets at Blizna up to the middle of March 1944, resulted in only 26 launchings. Of these 26 rockets, the vast majority disintegrated in the air, and only four reached the prescribed target area.
responsible for seeing that technical development and operational control of the weapon went hand in hand; at the same time, his appointment as ARKO (Artillery Commander) 91 placed him in charge of operations in the field. During the next few months a higher formation, LXV Armee Korps, was created under Lieutenant-General Erich Heinemann, an experienced artillery officer, to supervise the operations both of ARKO 91 and of Flakregiment 755 (W) (Colonel Wachtel), the unit responsible for flying bombs. Dornberger’s title as the officer responsible for active operations was then changed to HARKO (Senior Artillery Commander) 191. On the ground that he lacked experience in the field, he was, however, soon replaced by a newcomer to rockets, Major-General Richard Metz, though he remained responsible, as Special Commissioner, for technical development and training. In the following April Metz reported that, because of premature bursts and other technical shortcomings, the A-4 was not yet fit for use in war.28 At the same time he called attention to alleged defects in the training programme and to differences of outlook between himself and Dornberger, mentioned shortages of manpower which threatened to delay recruitment of launching units, and asked—in vain—to be relieved of his command.
In London Mr. Sandys and his helpers continued throughout the summer and autumn of 1943 their efforts to establish the nature of the threat. By the end of August there was a good deal in the evidence received from secret sources to suggest that at least two distinct missiles were in question—one a rocket some thirty to fifty feet long, another some kind pilotless aircraft (or flying bomb) whose dimensions were not known.29 No launching sites for either weapon had been identified with certainty; but a large construction which had been photographed at Watten, near Calais, was clearly of importance to the enemy and might well have some connection with the matter.
In fact, as we now know, the site at Watten was intended by the Germans to comprise a launching point for the A-4, a store for the rockets themselves and also for liquid oxygen, an oxygen liquefaction plant, and a place where the missiles could be tested, fuelled and serviced. Two similar ‘bunkers’ were under construction at Sottevast and Equeurdreville (both near Cherbourg), though the last was never adopted by the German Army and was ultimately converted into a protected launching-site for flying bombs. In the outcome it was never used in either capacity. In addition, rockets were to be launched by mobile units from a much larger number of unprotected but inconspicuous positions in Artois, Picardy and western Normandy.
On 27th August 185 Fortress bombers of the United States 8th Bomber Command attacked the site at Watten with excellent effect. A lighter attack followed on 7th September. The raids left the place
‘a desolate heap of concrete, steel, props and planking’, more or less useless for its original purpose, though part was afterwards roofed in and earmarked purely as a liquefaction plant. An alternative site was chosen in a chalk pit at Wizernes, some miles to the south, where an underground storage dump for rockets was already planned.*
From the standpoint of the present day, it is obvious that the attacks on Peenemünde and Watten were well timed and did good service to the Allied cause. We have seen, too, that soon afterwards any immediate prospect of rocket attacks on the United Kingdom was extinguished by the technical shortcomings of the weapon. At the time, however, the outlook remained so obscure in British eyes that there seemed little ground for optimism. The performance of the rocket, in terms of range and weight of warhead, was still unknown, as was the method used to launch it. In their attempts to throw light on these points, our experts were handicapped, not merely by their ignorance of the propellant favoured by the Germans, but also by the scant attention which had formerly been paid in this country to the whole subject of ‘liquid’ rockets.
During the late summer of 1943 a British fuel expert, Mr. I. Lubbock of the Asiatic Petroleum Company, visited the United States. There he was shown a fuel employed in experiments with assisted take-off of aircraft, and also suitable for rockets. The main constituents were nitric acid and aniline. More important still, he was made acquainted with the use of a pump to force such liquids into the combustion-chamber of a rocket, instead of the heavy compressed-air bottles hitherto envisaged. On his return to this country he produced, in a few days, a tentative design for a ‘liquid’ rocket with external dimensions similar to those photographed at Peenemünde.
According to Professor Ellis, the information brought back by Mr. Lubbock ‘completely altered the picture.30 In the light of it, ten members of a committee of eleven British scientists and technicians came to the conclusion that a single-stage rocket of the stipulated size, and ‘using existing American technique for liquid jet motors,’ could be made to give a range of 200 miles with a warhead weighing between one and five tons, or of 130 miles with a warhead up to fifteen tons.31 If thrust were increased by means demonstrated in laboratory tests in the United States, the range might be increased to 300 miles with the lighter warhead, or the weight of the warhead to five to twelve tons for a range of 200 miles and ten to twenty tons for a range of 130 miles. Dr. Crow, the eleventh member of the committee, dissented from these figures, but agreed that a multi-stage rocket, using the more primitive technique familiar in this country,
* For an account of the further development of the German programme, see Chapter 25.
might carry a warhead weighing between one and ten tons to the smallest of these ranges. Completion of these estimates coincided roughly with the receipt of evidence which led Mr. Sandys to conclude that the enemy might already have manufactured 500 rockets and that an early attack might be expected.32
Meanwhile the case for the rocket had been strengthened, too, by the appearance of the Henschel 293. Lord Cherwell was still sceptical, believing that, ‘at the end of the war, when we knew the full story, we should find that the rocket was a mare’s nest’; but his objections rested on the assumption that something like a sixty-ton rocket was still in view.33 Nevertheless the Defence Committee (Operations), at a meeting on 25th October attended by the Prime Minister and Field-Marshal Smuts, agreed on a further programme of counter-measures which bore witness to the gravity of the threat apparently presented by the weapon.34 These measures included high priority for attacks on factories believed to be engaged in making the rocket and on structures thought to be designed to house projectors; and a secret session of the House of Commons for the purpose of acquainting members with ‘the chain of events connected with the rocket, and the steps which had been taken over the last six months to find out about it, and to deal with it’.
Just over a week later the Minister of Aircraft Production, Sir Stafford Cripps, after presiding over a meeting of those whom he comprehensively called ‘the scientists and their assistants concerned with examination of the German long-range rocket’, reported that there was ‘nothing impossible in designing a rocket of 60-70 tons to operate with a 10-ton warhead at a range of 130 miles.35 Unfortunately—though reasonably enough in view of the huge mass still falsely attributed to the missile—the scientists and their assistants continued to mislead the intelligence services by insisting on the necessity of some form of initial propulsion, in the shape either of a mortar or of the first stage of a two-stage rocket. The rockets photographed at Peenemünde had wide fins which threatened to interfere with insertion in a mortar. On the other hand there was little in the evidence to suggest that the rocket was other than single-stage. On the whole, the more widely-favoured concept was that of a single-stage rocket fired from a mortar; and the search for mortars consumed much needless effort.36
Meanwhile a growing volume of evidence was reaching London about other, though related, projects. We have seen that in June the Defence Committee (Operations) agreed that Dr. Jones of the Air Ministry should be associated with those aspects of the investigation which bore on the application of jet-propulsion to aircraft, piloted or pilotless. Early in September the Air Ministry, at the request of Mr. Sandys, formally assumed responsibility for that part of the enquiry.
Within the next few months the Chiefs of Staff came to the conclusion that the problem of the rocket was entering a new phase. The chances of attack in the foreseeable future seemed to be increasing; and this possibility had led to a quickened tempo in the conduct of reconnaissance, the planning of counter-measures and the like. They concluded that the ‘special enquiry’ stage had passed and that henceforth counter-measures could with advantage be co-ordinated by an agency directly subordinate to one of their own number. After discussing the matter with Mr. Sandys they recommended to the Prime Minister that the functions he had hitherto performed should be transferred to the Air Ministry.37 Under the new arrangement, which was adopted during the third week of November, the Deputy Chief of the Air Staff (Air Marshal N. H. Bottomley) became responsible for co-ordination of intelligence and operational counter-measures with respect to rockets as well as to flying bombs. In order that the value of the experience gained by Mr. Sandys during the months which his investigation spanned should not be lost to the Chiefs of Staff, he sat with them thereafter when either weapon was discussed; and seven months later, when the flying bomb campaign had started, he returned to a more active role as chairman of a War Cabinet subcommittee appointed to watch and forward counter-measures. Responsibility for plumbing the mysteries of the rocket thus passed to the Air Staff.
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