Defeating the V-2 Missiles

The story of the struggle against the threat of the German V-2, the first-ever ballistic missile, and to a lesser degree against the V-1, the first cruise missile, is the story of a chance discovery of unexplained German activity, the attempts to understand what the air photos signified, and the refusal of senior scientists to acknowledge new technology they were not familiar with.

First Discovery

On May 15, 1942, a lone Spitfire sortied for a photo reconnaissance mission over the port of Kiel on the Baltic Sea. From there he was to fly to Swinemuende, a small military airfield at the south end of Usedom Island. About 250 kilometers east of Kiel, when he was near his objective, the pilot noticed that another small airfield, located in the north of Usedom, was being enlarged and vast construction works were being performed. The sudden bustle in this usually desolate area caught his eye, and he started his cameras for a short time, then continued to his original objective and returned to base.

When the pictures were developed, it was found that the pilot photographed a place named Peenemünde that up to then nobody had paid attention to. The photos showed that large construction was indeed going on there. Most interesting were circular dugouts, clearly discerned in the photos, that were bigger than customary for antiaircraft guns. The photo interpreters had no explanation, and the pictures were duly filed and the files put on the back burner.

Today we know that the development and production center for the German “Vengeance Weapons” (Vergeltungwaffen), and especially the V-1 and V-2, was located in that thinly populated place since 1936, in order to keep it away from possible observation and hide the then unusual noise of rocket motors. Also, its isolation and proximity to the sea enabled flight testing without the danger of stray missiles hitting a populated region.

Such an ambitious testing program could not be kept under wraps for a long time, and starting in December 1942 a steady stream of reports about a possible connection between Peenemünde and “secret weapons” trickled to British intelligence, which was getting more and more interested in the place. These joined the initial mentioning of Peenemünde and long-range weapons, including rockets, in the Oslo Report, which British intelligence got in November 1939 and which initially was not taken seriously.

New information about rockets surfaced in March 1943. This was the transcript of a conversation between two German generals taken as prisoners after El Alamein in North Africa at the end of 1942. One was Wilhelm Ritter von Thoma, who commanded Rommel’s armor, and the second was Ludwig Cruewell, who was Rommel’s second in command. The two were separated and made to meet only four months later in a room full of listening devices. Von Thoma told Cruewell that he had once seen the rockets in Germany. Knowing that their prison was somewhere near London but not hearing any large explosions, he thought that the rocket program was probably delayed. He also said that these rockets were intended to be fired at large-area targets and that on their way they climbed high into the stratosphere (R. V. Jones 1978, 333).

The apparent importance of Peenemünde to the Germans was further bolstered by a decryption of an Enigma transmission from the German air ministry dealing with petrol allocations to various research stations, listed according to some order of precedence. Peenemünde was second on the list, way ahead of other bodies whose importance was known (R. V. Jones 1978, 348). (This is an excellent example to how intelligence can come up with important insights by integrating apparently unrelated bits of information. What do priorities in gas allocations have to do with the development of long-range weapons?)

In view of the accumulation of such evidence, a detailed briefing was prepared for the chiefs of staffs. These, together with the prime minister, agreed that this German activity constituted a danger and decided to create a special working group for the “Peenemünde Problem.” A senior intelligence official named Duncan Sandys (who was Churchill’s son-in-law) was named to head this committee, and photo reconnaissance of the area was intensified, but the whole effort suffered from a basic problem: nobody knew exactly what they were seeking or what it should look like, if and when discovered. Another critical problem (which was only much later realized) was the fact that, in the name of “security compartmentalization,” various professional bodies, including the “Shell” company, which did research on rocket propulsion, were not consulted.

Finally, in June 1943, part of the mystery was solved. A “very thick vertical column about forty feet high” was photographed in one of the dugouts. A few days later, the photographs revealed actual rocketlike objects lying horizontally on road vehicles inside the dugouts, although “the cautiously worded report described them as ‘torpedo like objects thirty-eight feet long’” (Babington-Smith 1957, 150). Some people thought these were indeed long-range weapons (although nobody yet thought of guided missiles), while others rejected this conclusion out of hand.

The Big Debate

June 1943 brought a crisis in the debate over the meaning of what was found in Peenemünde. There were no doubts about the size of the objects. From the growing stock of aerial photos and reports of agents on the ground, it was clear that the length of these rockets (if indeed they were rockets) was about ten to eleven meters with a diameter of about two meters. The first difference of opinions was about its mode of propulsion. All concerned assumed a priori that if these were really rockets then they used solid fuels. Everybody knew about solid fuels, and the internal ballistics of solid-fuel rockets was reasonably well understood.

Solid fuels of that period were based on cordite, which is used also as the propellant in standard ammunition. In ammunition, the breech pressure reaches several thousand bars, but in a rocket motor the usual working pressure is thirty to eighty bars. In a solid-fuel rocket, the casing holding the fuel thus has to withstand these pressures. Assuming a reasonable working pressure, and considering the size of the rockets observed, a casing made of steel (with a reasonable safety factor) would have had a thickness of about two inches and weighed about twenty tons. Adding to this the weight of the fuel (in the observed volume) and the warhead, this rocket would have weighted at its launch about forty tons. This meant that just to start moving, let alone accelerate, the rocket motor had to deliver more than forty tons of thrust. Those twenty tons of fuel would not have sufficed to send the rocket to any meaningful distance.

Professor Lindemann, Churchill’s science advisor, objected vehemently to any interpretation of these findings as rockets, basing his objections on the above considerations of weight and thrust.

Because of his role in many of the controversies about German achievements in technology, a brief description of Frederick Alexander Lindemann is in order. Lindemann was a world-renowned physicist who taught at Oxford. During World War I, he volunteered to join the Flying Corps but was rejected for flying duty because of one bad eye. Instead, he was posted to the aeronautical research center at Farnborough. There he developed the method for recovering from a spin. At that time, spin was almost always fatal, and few pilots ever recovered from it while really understanding how they did it. Lindemann worked out the theory and then learned to fly at his own expense. When he felt confident enough he took an airplane up, he entered a spin and recovered from it. Every flying student today practices this technique.

At the end of the twenties, Lindemann became one of Churchill’s (who at that time did not hold any office) closest friends. When the Nazis came to power, he supported Churchill, who was against them and urged the government to strengthen the air force. Although Lindemann descended from a family that emigrated from Germany in the nineteenth century, he too hated the Nazis and helped Jewish physicists who escaped from Germany. When Churchill became the prime minister, he made Lindemann his scientific advisor and consulted him on many subjects. Among other activities, Lindemann established the Department for Statistical Analysis, which continually collected all bits of information about the British economy and worked out a set of reports and presentations that enabled Churchill to have a picture, almost in real time, of the economic resources of the nation. All this before the computer era! But he was also very obstinate, belittled those whom he considered his intellectual inferiors, and had the habit of finding faults in everything (Bowen 1987, 75; Keegan 2003, 331). Once he convinced himself of something, it was very difficult to make him change his mind.

At the end of 1934, the air ministry established a committee to investigate ways to improve the air defense of Britain—the Committee for Scientific Survey of Air Defernce (CSSAD)—also named the Tizard Committee, after its chairman, Henry Tizard, another famous scientist. Two more members were scientists (one current and one future Nobel laureate), and two civil servants who were involved in research-and-development policy. Churchill pushed the committee to accept Lindemann as a member. However, Lindemann, who had several pet projects of his own, especially in the infrared field, demanded that they be considered for development. After a year of conflicts, the two scientists on the committee resigned and the committee was disbanded, but it was later reconvened with its original members and an additional scientist.

When war broke out, Lindemann continued as Churchill’s advisor and as such accompanied Churchill to all meetings. However, his obstinacy and adherence to (scientific) prejudices, even when facts conclusively proved him wrong, soured his relations with many of his colleagues. He was against the use of “window,” against allocating centimetric radars to submarine hunting, at least as long as these radars were in short supply, and did not believe that the Germans were developing electronic devices for bomber navigation. No doubt his contribution to the war effort was considerable, but there is no question that many times his behavior caused delays. His opinions on what was going on in Peenemünde, if not blocked by other scientists, might have caused real damage, maybe even delaying the Normandy landings. The end result would have probably been the same, but in this kind of war victory is achieved by points, rather than by a knockout, and these points have a universal price: blood.

Based on solid-fuel technology and weight considerations, his objections were correct, but a scientist of his standing should have considered or been aware of other possibilities. His explanation of these being some kind of airborne torpedoes was discarded immediately. There was no airplane in Germany that could carry such a large torpedo. Lindemann then proposed that this was all some kind of a hoax. But since it was obvious that Peenemünde was an important facility, what would have been the point in creating a hoax that at best would have called attention to the place and at worst brought down a bombardment?

At the end of June 1943, another meeting concerning Peenemünde took place at Churchill’s headquarters. Over Lindemann’s strong objections, it was decided to bomb Peenemünde in order to eliminate the threat. Another debate then ensued: Should the target be the development and production facilities, or should it be the residence areas of the scientists? It was decided to bomb the residences. The attack was postponed several times and took place in the middle of August. The marking of the exact target by the “pathfinders” (Mosquito aircraft dropping colored incendiary bombs) was not accurate enough, and only the edge of the scientists’ living quarters was hit, with the loss of some 130 German scientists and technicians. The bulk of the bombs fell on the foreign forced-labor workers’ living quarters, where about six hundred perished.

The damage was not as extensive as hoped for, but the Germans still had to complete repairs and bring in replacements for the casualties. They also decided to disperse the facilities to minimize future bombing damage. All these measures delayed the program for a considerable time. Opinions differ as to the extent of this delay—from one month to six months—but there is no doubt that the raid prevented the Germans from dovetailing the V-2 attacks with the V-1 (the flying bombs that were developed in parallel to the V-2 ballistic missiles). Such parallel attacks, if they took place, would have put an unbearable burden on British defense measures. The delay enabled the British to get better organized, including the activation of a deception plan about the impact points of the V-2 missiles that did reach London, causing the Germans to correct their trajectories so as to hit empty fields.

The Internal British Disputes

With time, more details were revealed about the conduct of some persons, on the British side, who had access to the Peenemünde findings or were consulted about them. One of these who consistently argued that the Peenemünde “objects” could not be long-range rockets based on cordite was Dr. A. D. Crow. Dr. Crow was in charge of ammunition development in the British Ministry of Supply and the director of all rocket development programs in Britain. By dint of his position, he was present in all the meetings that dealt with the Peenemünde findings (including the Sandys working group), but because initially he was not familiar with liquid-fuel technology, he rejected any suggestion that the mystery objects constituted any threat.

It turned out that even he did not know all the details. In the beginning of 1941, much earlier than the events described, the British Ministry of Supply contracted the “Shell” company to develop rocket motors to shorten the takeoff run of aircraft. (Today these are called RATO—rocket assisted takeoff.) The most important clause in that contract was that these motors would not use cordite, which was in short supply. An engineer named Isaac Lubbock was in charge of this program, and because of the ban on cordite (and at that time the technology of composite fuels practically did not exist), he chose to develop a liquid-fueled motor based on aviation fuel and oxygen (Irving 1966, 61). Development progressed successfully, and in May 1943 a large group of senior scientists was invited to witness the firing of such a motor. Crow was present at that demonstration, but when he returned to London he did not report the event, and its success, to his colleagues on the Sandys group. In fact, because of the strict compartmentalization, nobody on the Sandys group found out about this development until late September 1943, a month after the Peenemünde raid (Irving 1966, 62).

Crow found an ally in Lindemann, and the two persistently contrived to show that such a large rocket, based on cordite, simply could not work. (Technically, they were correct, as explained already, but they rejected any other explanation of the Peenemünde findings.) A subcommittee for rocket fuels, in which both Lindemann and Crow were members (and in effect controlled it), prepared for the Sandys group a paper that said that the range necessary to hit London could not be attained by a single-stage rocket (Irving 1966, 155).

While the conclusions of this subcommittee were under discussion, Sandys was invited (in mid-October 1943) to observe a test of Lubbock’s liquid-fueled motors and was highly impressed.

On October 25, Churchill convened another meeting to once and for all decide whether the Peenemünde work (some of which was dispersed to other sites after the August raid) constituted a real threat. Lubbock was present too and presented his work, adding that the American Robert Goddard, who worked in the United States in the twenties and thirties, successfully launched several liquid-fueled rockets.

The minute liquid-fueled rockets were brought up, all objections to the idea of long-range weapons collapsed. The explanation to this is simple. Contrary to solid-fuel rockets, where the whole body serves as the combustion chamber and thus has to be able to withstand the full working pressure, in a liquid-fueled rocket, only the (relatively) small combustion chamber has to withstand this pressure, and the rest of the missile, including the warhead and the fuel tanks, just has to be able to carry its own weight plus launch and flight loads, and these are considerably less demanding. Also, liquid fuels contain more energy per weight than solid fuels. Recalculating now the weight of the rocket, a figure of about twelve tons emerged, and this was well within the capabilities of the rocket motor.

This question was thus settled, and the discussion moved on to more pragmatic lines, about preparations for V-1 and V-2 bombardment of Britain. At that time, neither the British nor the Americans could ascertain whether these rockets were guided in some way or not, and if they were what type of guidance was used.

The British bombed the launching sites of the V-1 and delayed their employment. The first were launched only on June 12, 1944, a week after the Normandy landings. In the meantime, the British continued tracking the V-2 testing at a growing number of sites. One rocket veered away from its trajectory and fell in Sweden. British intelligence, which had a working relationship with Swedish intelligence, examined the wreck and found that it contained many electronic components. Because the Germans worried about more bombing raids, they moved some of the testing to Poland, and one rocket landed in a forest. The Polish underground, which found it first, sank it in a nearby marsh. When the Germans gave up the search, the Poles pulled it out, removed some parts they considered important, and one of the men carried them on his bicycle two hundred miles to a rendezvous with a British C-47 that landed in a forest clearing (R. V. Jones 1978, 443–44). At this stage, even Lindemann was convinced and did not object anymore.

The first launch of a V-2 against London took place on September 8, 1944, three months after D-Day. In all, 1,190 rockets were fired against London until all launching sites within range were overrun in mid-April 1945. Antwerp took some 1,600 hits. But it was too late to stop the Allies.

Some Lessons

From the above description of events, it is evident that the critical question, whether to bomb Peenemünde or not, did not hinge on intelligence information (although this was available) but on the personalities of the people involved: Lindemann, Jones, Crow, and a few others. If Churchill was to act properly, he had to listen to Lindemann, his scientific adviser. After all, it was Churchill who gave him the job. At the meeting at the end of October 1943, Lindemann reiterated his position and added, “At the end of the war when we know the full story, we should find that the rocket was a mare’s nest” (Irving 1966, 162). But if Lindemann’s position would have been accepted, it would have caused considerable damage to the Allies, making the invasion more difficult.

Jones, in effect head of scientific intelligence for the RAF, confronted Lindemann back in 1940 when he suspected (based on bits of information) that the Germans were planning to use radar beams for bomber navigation at night—the Knickebein affair. Then, too, Lindemann dismissed Jones’s assertions as folly. Luckily, Churchill sided with Jones and ordered a more thorough test, which proved Jones right. Churchill remembered that incident and enjoyed reminding Lindemann of it, and it is quite reasonable to think that this was the reason for his decision to bomb Peenemünde despite the expected losses. In that raid, the RAF lost forty-one aircraft (nearly three hundred airmen) out of the six hundred planes that took part.

Crow was revealed as a person whose attitude was problematic. He preferred to hide critical information from his colleagues because it might have weakened his arguments. Although a distinguished scientist who contributed much to the British war effort, he refused to accept that single-stage liquid-fueled rockets could prove a practical weapon, even once he found out about them, and thus hindered the work of the Sandys group (Irving 1966, 156n).

The compartmentalization problem rose here in all its severity. It prevented the Sandys group from receiving timely information about the success of the liquid-fuel experiments, which was very relevant to its task. Every beginner in the intelligence business knows that the intelligence picture, whether operational or technological, consists of myriad details, some of which do not seem to be relevant (as in the above case of petrol allocations), and you can never know which bit will make the puzzle solvable. Finally, some of the logic dilemmas and conclusions that evolved from the V-2 affair, and which are applicable to many other topics, are presented and discussed by Jones, who was deeply involved in this subject (R. V. Jones 1978, 455–58).