by Hitler's Revenge Weapons- The Final Blitz of London (retail) (epub)
The failed attempt on Hitler’s life in July 1944 led to the replacement of Generaloberst Fromm, as head of the Waffenamt (Army Ordnance Department), by Himmler, thus giving him the greater influence in the rocket’s final development he dearly sought. In August, the Wehrmacht responded by creating what was, in effect, a private firm, the Peenemünde Elektromechanische Werk, to be run by the head of Siemens with von Braun as his deputy, reporting directly to the armament ministry. Himmler countered at once, promoting Kammler to Gruppenführer-SS, making him responsible for overseeing all aspects of V2 development and deployment, reporting directly to him. Potentially this could make life very difficult for the hard working, long-suffering Dornberger but, in the name of duty and loyalty to his nation, von Braun persuaded him not to resign. Residual trials work on the V2 had now moved from Blizna to Tuchola Forest (code name Heidekraut), in Poland.
By the end of August 1944 the Allies were advancing rapidly through north-west France, occupying the best sites for the flying-bomb operations against London, and the huge concrete silos destined for the V2, while causing General Heinemann’s LXV Army Corps to retreat into Belgium. Himmler then announced that he was promoting Hans Kammler to Obergruppenführer-SS and giving him command of all V2 rocket operations, in Operation PENGUIN, with orders from the Führer to begin firing half the rockets at London, and half at Paris, as soon as they became available. So it was that General Heinemann and his deputy, Oberst Walter, ceded operational control of the missiles to the SS, remaining responsible only for such services as intelligence, the prepositioning of weapons and guard duties. At the same time, news came through from Heidekraut that Dornberger had finally mastered the airburst problem by riveting a metal sleeve around the fuel tank compartment. Seemingly, the V2 was now ready for war and it was time for Hitler’s’ final fling’(Chapter Ten).
Redundant rail link to Baltic coastal test stands. (Author, Courtesy HTM Peenemünde)
Similar infighting had been raging within the Luftwaffe, with its political masters and with the German Army. Typically, Generalfeldmarschall Erhard Milch, the Luftwaffe’s Inspector General and head of the Air Ministry’s Technical Office charged with aircraft production, and General Ernst Udet, Director of Research and Development and later Director General of Luftwaffe Equipment, were continually at loggerheads. Both were avowed Nazis, loyal to Hitler and their direct master, Hermann Göring, but neither was known to be a clever strategist or tactician, and the endless debates on the way ahead for the flying bomb were driven as much by politics and personal agendas as by the imperatives of war. While there was dismay in the air force when Göring ordered the cancellation of the German heavy bomber programme, his obsession with numbers arguing that two and a half medium bombers (Heinkel He111, Junkers Ju88 and Dornier Do17) could be produced for the cost of one such bomber, this should have helped prospects for the flying bomb. However, Göring and others within the German hierarchy were against priority treatment for the two missiles; this was reflected in February 1940 dictum that all work should be stopped on new aircraft and associated projects which could not mature and reach the front line within the following twelve months. This seems a very surprising decision, reiterated as late as September 1941, in that it was very much to the detriment of a continued advance of the new German technologies already in train.
Undeterred, and with sensible foresight, the aircraft industry had continued with those military projects which they believed would be needed in the future, as private ventures, and in the flying bomb the gamble paid off. In Berlin, Milch, recognizing that his all-important weapons development programmes could quickly lose its momentum, forged a closer relationship with Albert Speer, who had taken over as Armaments Minister in February 1942; the two realised that the flying bomb, already in an advanced state of design, could be a viable substitute for the heavy bomber. They also believed that, with the RAF’s fearsome raid on Lübeck still on his mind, Hitler would welcome a reminder of the chance to exact revenge in kind with the rocket and flying bomb while, inter alia, raising the Luftwaffe’s morale. They argued that the flying bomb would be a sensible adjunct to the Army’s V2 rocket, without any great demand on scarce resources, such as precious aviation fuel, the pulse-jet running on standard petrol.
In this VIP visit to the A4 (V2) Test Stand VII at Peenemünde in 1944, Generalmajor Dornberger and Generaloberst Fromm (right) escort Generalfeldmarschall Keitel (centre) and General Warlimot. (Author, Courtesy HTM Peenemünde)
This boded well for Gosslau of Argus and Lusser of Fieseler, the main protagonists of the unmanned flying bomb, who sensed that the time had come for them to submit their optimistic progress report on the tests and trials they had carried out and on their projections for the future. This they did on 28 April 1942, with specific proposals to the Reichsluftfahrt Ministerium (RLM), the German Air Ministry, for a cruise missile carrying a half-ton warhead over a range of 186 statute miles at speeds of 435 mph. This was a tall order but the proposal was rushed through the staff channels for the final version to be submitted to the Air Ministry on 5 June and signed off by Milch on 19 June 1942, a mere seven weeks after it had been tabled. Moreover, the project was included in the Luftwaffe’s Vulkanprogram (Volcano) programme, giving it the priority it needed in the allocation of resources. In Germany, the Fieseler flying bomb would be christened Fi 103, and be known as Vergeltungswaffe Eins (V1) (Retaliation Weapon 1), but with the cover name Flakzielgerät-76 (FZG-76) (anti-aircraft aiming device-76) and nicknamed Maikäfer (Maybug), all within Project Kirschkern (Cherrystone). To the Allies it would be the V1, the Pilotless Aircraft (PAC), ‘FLY’, ‘Buzz Bomb’, ‘Doodlebug’ or ‘Diver’.
With Lusser in charge of the airframe, Gosslau the engine, Guido Wünsch the guidance system and Rheinmetall-Borsig the catapult, work on the V1 then accelerated. The 25-foot fuselage, built of steel sheeting wrapped around and welded to tubular formers, would house the ‘brains’ of the missile, its short, stub wings, spanning a mere 17 feet 6 inches, were mounted well back, while a standard tailplane, with horizontal stabilisers and fin, was fitted with conventional elevators and rudder, the fin also supporting the pulse-jet engine and its long jet pipe. This was a simple monoplane, resembling a small fighter aircraft. A sophisticated, integrated control system incorporated an autopilot which governed altitude and airspeed, while a weighted pendulum, damped by a stabilized gyrocompass, controlled pitch and roll. Rudder control was sufficient for the limited directional changes required, thus eliminating the need for wing-mounted ailerons. All power requirements, together with pressurization for the fuel tanks, were provided by compressed air stored in two large spherical tanks, resembling giant golf balls. For ground launches, the V1 would be attached to a cradle, to be driven up a 150 feet inclined ramp by a piston in a slotted tube, given an initial thrust of 66,000 pounds by steam generated in a combustion chamber containing a mixture of hydrogen peroxide (T-Stoff) and sodium or potassium permanganate (Z-Stoff). When reaching flying speed, the pulse jet would take over and the cradle would detach and fall away.
The first V1 airframe was delivered to Peenemünde on 30 August 1942, only two months after Milch had given the go-ahead for Project Cherrystone, and static tests began two days later. These tests, and others carried out in the Hermann Göring Wind Tunnel at Braunschweig-Volkenrode Aeronautical Institute, revealed that the pulse jet stalled at high speeds and generated excessive vibration, also that thrust decreased with increases in speed. With these defects believed remedied, the first ground launch of a V1 took place on 24 December 1942, the tiny aeroplane riding up the ramp on its sled and into the air correctly, the engine starting and separation from the sled taking place as planned. While this first flight lasted less than a minute, the embryo missile achieved a speed of 310 mph and the test was deemed to have been a great success, generating much needed confidence in the project and resulting in the formation of an Arbeitsstab FZG-76 (a V1 Project Team), which included Gosslau and Lusser, to supervise the missile’s devel
opment and production.
With confidence now high, Hitler, Göring and Himmler were invited to Peenemünde again in January 1943 where they witnessed a faultless launch, after which the missile veered off to the right and crashed – as it had in previous tests. The project team was nonplussed but the diminutive test pilot Hanna Reitsch came to the rescue by offering to fly the V1 to evaluate the problem, if it could be fitted with a cockpit and basic controls. This was quite practicable, and while there were grave concerns within the Nazi hierarchy, and Hitler himself, over the dangers inherent in such a hazardous initiative, the desire to solve the problem eventually prevailed, and on Hanna’s fourth test flight in the re-configured aircraft, the cause of the problem was revealed. It had become clear that the steam-driven sled was unable to withstand the shock of the catapult launch, one or more bolts shearing and causing the wings to flutter at a crucial stage in the launch. Stronger bolts were fitted and the trials resumed with such success that full production began in May 1943.
By the end of July 1943, eighty-four launches had been attempted, of which sixteen were dropped from a ‘mother’ aircraft, and sixty-eight catapulted from the ground, but only twenty-eight of the latter going to plan. Other than the defective launches, the main cause of the failures was the disintegration of the airstream inlet shutters which, in any event were only expected to function correctly for the one flight planned for each missile. There was some good news, however, one V1 achieving a speed of 390 mph and another a range of 140 miles, close to the performance figures predicted. Significantly, none of these test flights carried guidance equipment, and none were carried out at the maximum operational weight. Inevitably, the ‘blame-game’ for all the failures was in full swing but there was general agreement that the rush to get the missile operational had led to inadequate tests of critical components and analysis of the failures.
When it was believed that the causes of all these failures had been found and remedied, fully-loaded V1s were put through their paces with the Askania guidance system fitted to operate the flight controls, using compressed air to ensure that the directional gyroscope remained aligned with, or returned to alignment with, the pre-set magnetic compass. At preplanned ranges, small explosive charges opened spoilers on the horizontal stabilizer to tip the missile into a dive on to the target. However, no way had been found of compensating for high crosswinds and the use of mechanical rather than electrical range counters were insufficiently accurate to render the V1 a precision weapon.
The date for deploying the weapons to their launch sites in the Pas de Calais, set for December 1943, was very much at risk. Fieseler in Kassel could not generate the number of bombs required, and a second production facility coming on line at Volkswagen’s Fallerslaben factory was not able to make up the deficit, the total output falling well short of the 50,000 units per month, demanded by Göring. An initial command structure was in place, with Oberst Max Wachtel appointed commander of Lehr-und Erprobungskommando-V (a V1 test and training facility), at Zamplin, conveniently close to Peenemünde, and it would be he who had the unenviable task of explaining why the demands of the leadership could not be met in the timescales specified. A suitable workforce was proving hard to find, only 65 per cent of that needed, fully trained, was expected to be available by the end of July 1943, with increased Allied bombing demanding additional manpower to build up the fighter force, while the V2 rocket team seemed to be getting more than their fair share of what was on offer. Moreover, there was insufficient ground support equipment and many of the V1s arriving at the new training unit were found to be defective or without essential components, 60 per cent of those declared ready for use failing to launch correctly or to perform as required in flight.
The obvious vulnerability of Peenemünde to Allied bombing, led to the construction of another launch and training facility at Brüsterort, north of Königsberg, and it was there that Flak-Regiment 155(W) (Flak Regiment 155(W)), the first of the V1’s operational units, began its training on 1 September 1943, the first V1 being launched from there later that month. The initial V1 output at Fallersleben was two units per day, far below the basic training requirement of 6 per day, and there was no possibility of 155(W) completing its training by the target date of 1 October. Milch, however, still believing that the flying bomb would eventually alter the course of the war, and that Londoners would not be able to withstand a bombardment of one bomb every twelve minutes, kept up the pressure and, notionally, Flak Regiment 155(W) did become ‘operational’ in October 1943, firing its first missile later that month. While this did not tell the whole story, it would be fair to say that the regiment, although still lacking critical items of equipment and specialist manpower, when it moved to northern France shortly thereafter, did pave the way for the V1 ‘Doodlebug’ to go to war (See Chapter Five).
Arguably not one of Hitler’s ‘retaliation’ weapons, in that it could not threaten England, RMB’s Rheinbote deserves a mention, because it made use of technologies developed for the Aggregate rockets, and did affect the battles as the Allies advanced into Europe. Testing this multi-stage, solid-fuel, long-range artillery rocket began at the firm’s weapons range at Leba, in the Gdansk region of Poland, in 1941, with ten launches stretching over a full year. The first three stages of the rocket were tested independently before all four were launched together, culminating in April 1943 in a very successful demonstration before a VIP audience, which included the head of rocket development in the HWA, General Schneider. This secured official approval for further tests but without granting the priorities in materials it needed, the shortages only being resolved when the project officer, Lieutenant Colonel Alfred Tröller, ‘buried’ the extra requirements within the whole Vergeltingswaffen programme, hinting darkly that the SS were becoming interested in the project. Perhaps it was as a result of this ominous suggestion that the Wehrmacht was quick to authorise the supply of propulsion powder and metal necessary for the immediate production of 200 Rheinbote, at RMB’s Berlin-Marienfelde factory. The test programme then encountered further problems with repetitious airbursts attributed to inconsistent burning in the fourth stage combustion chamber, while the fins tended to break off at supersonic speeds. Both problems having been remedied, further demonstrations took place at Leba on 15 November 1943, before another select group of VIPs, now including Gruppenführer-SS Kammler and Generalmajor Dornberger, this time with mixed results. The first three rounds achieved ranges in excess of ninety-three miles, but with some disappointment at the limited effects of the small warhead, while the fourth broke up after launch, causing panic among the onlookers. As a result, Dornberger recommended that further work on the weapon cease forthwith but he was overruled by Kammler who ordered the rocket gun to be deployed for immediate use on the front line, and allocated the necessary resources to that end.
Fi 103 (V1) Baltic Air Weapons range, off Pomerania. (Author, Courtesy HTM Peenemünde)
The original offices and workshops on the southern edge of Flugplatz Peenemünde, where the Fi 103s were prepared for the flight trials. (Author)
Steam Generator, to power piston in launching Fi 103. (Author, Courtesy IWM Duxford)
This was not the end of the trials. Tröller and the RMB specialists continued to work hard to increase the reliability of the rocket, its performance and effectiveness, using the range at Leba and at Waldheim (re-named Drogoslaw), close to the V2 test range at Tucheler Heide, in Poland. Improvements came slowly, ranges increasing to 118 miles, and craters now measuring 11 feet (3.3 metres) in diameter and 4 feet (1.2 metres) deep, with greater destruction all round. However, the rocket was still unreliable, ignition between the stages remaining one of the main problems. Of Kammler’s initial order of 300 projectiles, only 115 had been delivered by the end of 1944, with the promise of 222 by the end of January 1945. Meanwhile, all the necessary support facilities were prepared, often by innovation or improvisation, typically with the V2’s Meillerwagen being modified for the rocket’s transportation and erectio
n and, by the end of 1944, sufficient firing teams had been trained for the tactical deployment of one battery of Artillerie-Abteilung 709 (Artillery Regiment 709) – and so the Rheinbote went to war.
Fi 103 launch sites, between Flugplatz Peenemünde and Baltic coast. (Author, Courtesy HTM Peenemünde)
Fi 103 (V1) tracks over Baltic range, pre-modification. (Author, Courtesy HTM Peenemünde)
Fi 103 (V1) tracks over Baltic range, post-modification. (Author, Courtesy HTM Peenemünde)
Chapter 4
No Hiding Place
It was perhaps surprising that Allied intelligence agencies were a little slow in recognising fully or accepting the sinister dangers that were lurking within the German scientific, technological, armament and military communities during the 1930s, as that nation began to circumvent or ignore, quite openly, the constraints imposed at Versailles. There was little attempt to conceal the rocketeers’ work at Kummersdorf, but only the naive could have believed that, as the Nazi movement gathered strength, this was solely to do with space exploration, and they could surely not have missed the significance of the HVA’s move from Kummersdorf to the huge new, highly classified facility at Peenemünde, which began in 1937. There seem to be several reasons why Britain was slow to react to tell-tale signs of these threats, one being a high degree of scepticism at the top, that if Britain had yet to make progress in the field of rocketry how could the Germans be so far ahead? Then there were those who thought that significant information which came their way, some almost incidentally, or was offered to them on a plate, was ‘misinformation’ deliberately ‘planted’, a ruse to mislead and distract. Also, there were those who thought they should be given the lead in seeking the truth, but were not, and conversely others who hesitated to become involved lest the search for the new airborne weapons being hinted at turned out to be a wild goose chase. All this scepticism and lack of definitive intelligence, examples of which follow below, led to procrastination and serious, perhaps near crucial, delays in responding to the threats inherent in the weapons which did materialise, eventually allowing German innovation to cause such havoc among the Allies in the closing stages of the war.