Hitler's Rockets: The Story of the V-2s

by Norman Longmate

  On 20 July, Herbert Morrison was also busy writing to the Prime Minister:

  It is clear, I think, that there is something wrong with the Intelligence side. It was a surprise to me, as it appeared to be to you, that we should have been told for the first time on Tuesday that the scale of attack envisaged was four or five times greater than had previously been contemplated . . .. We are having to deal with a potential . . . menace of great gravity, which may materialize at any moment, on the basis of evidence which is both scanty and conflicting. It might be worthwhile to consider whether there is not an undue number of official and other meetings about the organization of our counter-measures which may leave insufficient time for those with executive responsibilities to get on with their jobs.

  Churchill discussed this note with Duncan Sandys that afternoon, but on 26 July Herbert Morrison circulated another paper, uncompromisingly entitled: ‘Long-Range Rocket. Need for Re-Examination of Government Plans’:

  Nearly a year ago, and in an atmosphere of scepticism, the Cabinet instructed that paper plans should be drawn up for dealing with attacks on London by long-range rockets of heavy explosive content. . . . With the emergence of the flying-bomb . . . the plans . . . were put on one side. Last week, however, we were advised by Intelligence that 1000 rockets with a range of possibly 200 miles were believed to be in advanced state of preparation and that the warhead weighed probably 7 tons. . . . The latest theory is that no elaborate launching sites are necessary and . . . that the enemy will mount an attack on a fairly considerable scale.

  On the basis of flying-bomb experience, and scaling up the casualties caused by its one-ton warhead, Morrison calculated that, if 60 per cent of the rockets landed in Greater London, ‘about 30 per projectile would be killed’, producing 18,000 dead ‘from the assumed stock of 1000 rockets’. The number of seriously injured he put at three times that figure. To meet this need, if the London hospitals were cleared of other patients, as in 1939, and treated as ‘casualty reception units’, with patients being evacuated after initial treatment, ‘about 4000 cases could be handled per day . . . just double the worst day in the 1940/41 blitz’, but ‘the strain on staff would, of course, increase with each successive week’ and ‘it is . . . possible that the hospital service would be swamped’. As for house damage, Morrison forecast that ‘each rocket . . . would be likely to produce A and B damage’ (i.e. houses demolished or having later to be pulled down), ‘within a radius of 600 feet, C damage’ (houses uninhabitable until given maajor repairs) ‘up to 1200 feet and D damage’ (where the occupants could remain but with ‘appreciable discomfort’ up to 2400 feet, with ‘a considerable amount of minor damage to roof coverings, odd windows, etc.’ beyond that area. Inevitably, thought the Home Secretary, there would be a mass flight from London:

  The exodus might reach such proportions as to present a completely unmanageable problem both for the police and for the railways and the pressure of evacuees by bus, tube or on foot on the north and west perimeter of London might result in the complete breakdown of the emergency accommodation and feeding arrangements. . . . Many workers would leave London with their families in order to make sure that their families were settled in a place of safety. . . . It is quite impracticable to devise any system of control which would effectively secure that the people who ought to stay, stay, and the people who ought to go, go.

  As for morale, one of Morrison’s official responsibilities, this was already suffering from the flying-bomb and would grow worse:

  The British public will accept hardship, suffering and casualties that are due to unpreventible enemy action. They will be less ready to submit even to inconvenience which they judge to be due to government inactivity or lack of preparations. . . . As the areas of sheer devastation grow under continuous bombardment, I fear the public will become angry. . . . In my view the rocket attack must from now onwards be regarded as a major effort by the Germans to avoid sheer defeat. It must be met by us by a corresponding effort, both in active attack and passive defence, and not regarded as fatalistically inevitable.

  A Cabinet meeting that day gave Morrison the opportunity to underline these points in person and to strengthen them by reporting the effects of the flying-bombs: 16,000 dead or seriously injured in London alone in six weeks and 700,000 houses damaged. Cherwell now weighed in with his view ‘that the assumptions made by the Home Secretary as to the scale of attack were unduly pessimistic’ and that ‘he doubted whether the available stocks of rockets were as large’ or ‘whether the size of the rocket warhead would be as great as had been suggested. Again, the estimates of damage and casualties were based on a degree of accuracy which the rocket was unlikely to achieve’. These were all perfectly sound comments, but by now Morrison’s alarm had infected his colleagues. Duncan Sandys said that ‘the probable scale of attack’ might be ‘considerably heavier’ than the Home Secretary had described, the Minister of Health admitted he was planning, if necessary, ‘to clear the London hospitals completely’, the Minister of War Transport was ready to move 250,000 people a day up to twenty miles out of London, and the Chancellor of the Exchequer spoke of the need for protected accommodation for up to 55,000 civil servants. The Minister of Production was already dispersing some manufacturing effort, while even Morrison’s traditional adversary, Ernest Bevin, Minister of Labour, had a helpful suggestion to offer – that Double Summer Time, due to end on 13 August, should be extended. This was agreed, and on 3 August it was announced that the nation could enjoy its second extra hour of daylight until 16 September.

  Meanwhile Morrison’s right-hand man, Sir Findlater Stewart, had been discussing with other departments how ‘to prevent information on the fall of shot reaching the enemy’, and his proposals were circulated by the Chiefs of Staff on this same day, when rocket fever reached its peak. The restrictions, the Chiefs of Staff commented, were ‘more stringent than those proposed for OVERLORD and would include . . . the suspension of diplomatic mail and telegrams . . . other than American and Russian’, a total ban on all overseas travel, except for servicemen and government officials, and the virtual cessation of telegraph and postal services, at least for the first forty-eight hours. Telephone calls, especially to Ireland, would be monitored and be liable to be cut off. So drastic was the scheme for depriving the Germans of any hint where the rockets were falling that even Sir Findlater Stewart himself was doubtful if it could be kept up for much more than ‘a week or ten days’, but the Cabinet, on 28 July 1944, nevertheless accepted it, against the opposition, so far as diplomatic communications were concerned, of the Foreign Secretary, Sir Anthony Eden (later Lord Avon). Eventually he got his way in the case of the United States and Russia, partly on practical grounds ‘since the United States Embassy possesses direct lines not under our control and the Soviet Embassy has a private wireless transmitter’. He would instead make a private approach to ‘the two ambassadors not to send any information about rocket attack by this means’.

  Elaborate plans also went ahead for mass evacuation, largely in the hope of anticipating the panic flight which seemed the likely alternative. People leaving, it was proposed, would make their way on foot along eighty-seven preselected routes to a number of assembly points such as cinemas, where buses would be waiting to take them the short distance required to remove them from the target area. The Ministry of Home Security also made its own private preparations. ‘A new map of Greater London’, an internal memo announced, ‘is being mounted in the Map Corridor on which BIG BEN incidents will be plotted’, with the numbered coloured pins at present used to mark incidents being replaced by others in black once the rocket was known to be responsible. That day, too, the Cabinet set up a new Rocket Consequences Committee, presided over by Herbert Morrison, the other regular members being the Ministers of Labour, Production, Health and War Transport, with additional ministers being invited as necessary.

  This was also a busy time for Air Intelligence. The industrious and daring Poles had by now compiled a ma
ssive 4000-word document on the rocket, ‘Special Report 1/R, No. 242’, accompanied by eighty photographs, twelve drawings, a sketch map of Blizna, a list of all known rocket firings – and, they now proposed, eight10 large parcels of rocket parts, which could, if London agreed, be collected by a Dakota flying from southern Italy. With typical effrontery they proposed to use an abandoned German airstrip at Tarnow, 200 miles from where the rocket had crashed, to which the key items were transferred by bicycle. The operation, on the night of 25 July 1944, proved even more hazardous than anticipated, for two German Storch aircraft were using the airfield – fortunately they took off again – and after the British aircraft had landed safely it proved reluctant to leave the ground:

  The engines roared, the aircraft vibrated, moved forward a few inches and stopped. It had been raining for the last few days and . . . the wheels had sunk in and made take-off impossible.

  Flight Lieutenant Szrajer [the Polish co-pilot and interpreter] . . . ordered all the passengers to get out and the baggage to be unloaded. . . . The soldiers of the reception team were ordered to dig small trenches in front of the aircraft’s wheels and fill them with straw. . . . The plane still refused to move and once more the door was opened and everyone ordered to get out. . . . Flight Lieutenant Szrajer . . . decided to make just one more attempt. The soldiers ran to the carts, brought over boards and laid them under the wheels. For the third time the wretched passengers were told to board . . . and the luggage was loaded on. Eighty minutes had passed since the aircraft had landed and the short July night was beginning to brighten into dawn. This time, at last, the Dakota began to move and its take-off was accompanied by the joyful shouts of the underground soldiers who ran alongside waving their weapons and caps.

  The arrival of the rocket parts, at Hendon, on 28 July, was also not without drama, for the Pole in charge of them, who knew no English, refused to hand the cargo over to anyone except General Bor, commanding the Free Poles in the United Kingdom, or a Polish colonel whom he knew. When British intelligence officers tried to persuade him he drew a knife, and everyone was relieved when General Bor finally appeared. The information the suspicious messenger had brought, when finally in the hands of Air Intelligence, proved very useful, providing, among much else, the first news of the airbursts which had so troubled Dornberger, which seemed to confirm that it was not yet ready for operational use.

  On 31 July the Joint Intelligence Sub-Committee dealing with the rocket issued a paper entitled ‘Imminence of Attack by BIG BEN’, which was circulated to the Cabinet two days later. It was far from reassuring:

  It might well be that about a thousand of these rockets exist. . . . Launching sites exist, are of simple design and easy to construct. Plants for producing liquid oxygen in France and Belgium . . . are known to have been constructed. . . . Personnel have been trained in handling these weapons and at least a skeleton organization exists in the west.

  Why, then, had the rocket not yet been fired? The Germans might, it seemed, be waiting till they could ‘launch the operation at greater intensity’. But this was only a respite:

  In mid-July a well-informed high-ranking officer told a usually reliable source that BIG BEN would probably be used within two or three months’ time. . . . [There was also] a report from a usually reliable source . . . that BIG BEN would be launched by the beginning of September. . . . We therefore feel that a heavy and sustained scale of launchings against this country is unlikely to develop during August.

  Meanwhile Dr Jones was hot in pursuit of the rocket’s remaining secrets. One valuable prize was a wooden replica, full-size as was confirmed later and as seemed probable at the time, of an A-4 – Cherwell’s ‘great white dummy’ in reality11— found in a quarry at Hautmesnil, between Caen and Falaise, abandoned by the fleeing Germans. This, Dr Jones guessed, ‘had clearly been used to give the troops experience in handling the missile around the bends in the tunnels’. The same site yielded a heavy trolley, correctly assumed to have been used to transport the real missile, enabling its dimensions to be calculated beyond argument and from the slope of the nose cone, deduced from the curve of the front section, an informed guess to be made about its weight, the most vital clue to its likely range and explosive payload. The total weight was now, around the end of July, put at 24 tons maximum, which Dr Jones still suspected to be on the high side.

  Identifying the rocket’s fuel was also important, both in indicating its possible performance and as a guide to Allied bombing policy. Information from the Swedish and Polish rockets, along with signals, intercepted by Bletchley, between Peenemünde and Blizna, all referred to each A-4 requiring 4.3 tons of ‘A-Stoƒƒ’, and to another fuel known as ‘B-Stoff’. This led Dr Jones to the conclusion that the former was probably liquid oxygen and the latter might well be alcohol. This hypothesis made immediate sense of much that had hitherto been contradictory and on 6 August Dr Jones reviewed all the existing reports on the rocket, eliminating any that did not refer to liquid oxygen or liquid air. Only five survived, three from agents and two from prisoners of war, and, in contrast to the rest, they showed a remarkable amount of agreement. Even more significant, all were to some extent validated by their pointing to a rocket from 9 to 16 metres long and around 1½ metres in diameter which, from the recent, quite independent, discoveries, was now known to be correct. This in turn suggested a fuel weight of about 8 tons, in line with the Ultra evidence, and an all-up weight of up to 10 tons, with a warhead of between 1 and 2 tons, the lower figure appearing in four of the six reports. The latest interrogation report was only two days old, and Dr Jones and his assistant drove out to see the prisoner concerned and decided his information was reliable. It was borne out, too, by another fruit of Bletchley’s eavesdropping, a mention of one-ton ‘elephants’ being shipped between Peenemünde and Blizna. What more likely than that the ‘elephant’ was a rocket’s warhead?

  Oddly, having earlier faced up to the appalling prospect of 70 ton rockets carrying a 10 ton load of high explosive, none of the ministers or scientists on the ‘Crossbow’ Committee was now ready to see the threat reduced to more familiar and manageable proportions. A meeting on Thursday, 10 August, with Herbert Morrison in the chair, was unimpressed by the new evidence Dr Jones laid before it and concluded ‘that it was too early to draw a firm conclusion regarding the smaller size of the warhead of the rocket’. Next day Lord Cherwell, now proved right in rejecting the ‘giant rocket’ but concerned that Jones might have ‘cut it down to size’ too drastically, telephoned Dr Jones to advise him to leave himself some ‘loophole of escape’ over the rocket’s weight. ‘They are all waiting for you to make just one mistake and I am afraid that you have made it now!’ he warned his former pupil. But Cherwell himself, who on his way to Oxford for the weekend called at Farnborough, where the captured A-4 trolley was being studied, and the Swedish and Polish rockets were being pieced together, was convinced. On the Monday, 14 August 1944, he wrote to Churchill stating that the one-ton warhead was an established fact, but adding, very typically, that the rocket remained such an uneconomic means of delivering this weight of explosive that ‘Hitler would, I think, be justified in sending to a concentration camp whoever advised him to persist in such a project’.

  Dr Jones faced one last hurdle in getting what he was convinced were the true facts accepted, for the engineers rebuilding the Kalmar rocket reported that the design pointed to a warhead of only 1300 to 1500 lb, so he had now ‘to convince the Farnborough experts that their estimate was too low’, owing, it soon appeared, to ‘a segment missing, which . . . would have increased the size of the [nose] cone significantly’. The warhead was now finally put at 2000 lb, or just under a ton (2240 lb) – a remarkably accurate estimate. The true figure, as we now know, was 2200 lb, of which 1650 lb (750 kg) was high explosive, and the rocket’s total weight 12.65 tons (12,900 kg) against Dr Jones’s calculation of ‘about 12 tons’.

  On 21 August 1944 the Air Ministry updated its ‘Standing Instructions for Duty
Group Captain . . . in the event of Rocket Attack’. The ‘use of a considerable number of alternative firing points of simple design’ was now anticipated, known sites being identified by the singularly inappropriate name ‘Pop Gun’. Although ‘a constant watch for rockets at certain specially equipped radar stations on the south coast’ was now being maintained, ‘the firing of rockets’, it was acknowledged, ‘may not be detected by . . . radar . . . in which case incidents will be reported by the Ministry of Home Security’. The precise wording for this dread message had already been laid down and had a curiously ecclesiastical ring: ‘This is Home Security War Room speaking. Big Ben has been confirmed!’

  On 26 August 1944 Dr Jones completed a 30,000-word report setting out in detail the facts about the rocket, and the evidence and reasoning that had established them. The range he now put at ‘200—210’ miles; the German figure was in fact 207. The total stocks he estimated at ‘perhaps 2000’ – the actual figure was 1800 – and monthly production at ‘about 500’; the average for the period the campaign lasted proved to be 618. Of overwhelming interest to the Civil Defence authorities was the ‘intended monthly rate of fire’, which he calculated to be ‘about 800’; the German target was 900. This last figure was based on a series of deductions, a classic example of how intelligence could postulate the unknown from the known. A map showing the location of both genuine and ‘decoy’ sites west of the Seine had been captured, and it seemed likely that the tidy-minded Germans would follow the same ratio of real sites to dummy ones east of it. The same map indicated the storage capacity of the real sites and the likely rate of fire was worked out from flying-bomb experience, where captured sites had shown the German practice was to keep two weeks’ consumption in hand.