In order to overcome these problems a remote control system was tried, a version of the ZSG Radieschen, a passive radar which was fitted to the BV 246 glider bomb and homed in on enemy radar and Loran transmitters. This 15 kg target-seeker was found successful. A similar idea was in effect for the A9/10 rocket. The remaining technical problems to be surmounted were the relatively poor quality transmitters available and the need to have somebody put the set in place and turn it on at the right time at the target end. This meant that a number of agents would have to be landed in the United States for the task. A special version of the sea-launched V-1 was ready for use in November 194414, probably the Fi-103E, but the OKL development contract awarded to the Deutsche Forschungsanstalt für Segelflug for the V-1 Radieschen, which resulted in the Ewald II homing device and the Sauerkirsch II radio remote control system, did not bear fruit until April 1945, by which time hopes for the V-1 campaign were dead.
The V-2
The V-2 was the A-4 giant rocket 14 metres in length, 1.6 metres at the widest point of the fuselage and 3.5 metres across the tail assembly. Takeoff weight was 12 tonnes including a 1-tonne warhead in the nose. The rocket was transported aboard a chassis known as a Meillerwagen which was towed by a road or rail locomotive. At the launch point it was raised upright on the detachable starting platform for firing. The fuel was a grain alcohol/liquid oxygen mixture which burned for about a minute before the rocket fell to earth in a ballistic trajectory. Maximum altitude was 80 kilometres and the range was up to 305 kilometres. During powered flight the projectile was remote-controlled from the ground or regulated by an onboard gyro-compass.
The impact of an A-4 was equivalent to fifty 100-ton steam locomotives hitting the ground simultaneously at 70 mph. Even without its warhead the rocket would excavate a crater thirty feet deep and 75 feet in diameter. The London correspondent of a Swedish national daily reported: “I have personally seen great craters made by the V-2. In urban areas a single projectile can ruin 600 houses. It is not the explosion or blast that does the damage, but the tremendous earthquake effect.”
Accuracy was poor, however, and only 50% fell within 10 kilometres of the aiming point.
The V-2 offensive against London opened from The Hague on 8 September 1944, the first missile falling in Chiswick; the last fell on 27 March 1945. The despatch rate began at four per day and climbed to twenty-five units per day. Of 1269 launches against England, 1115 rockets (87%) arrived. The death toll from these was 2724 persons. 1739 A-4 missiles were fired at cities in France, Belgium and Holland, plus ten at Remagen, of which 1265 (73%) arrived, causing 7000 fatalities.
271 (0.8%) rockets of the total fired were designated failures.15
Whereas General Dwight Eisenhower was of the opinion in his memoirs that if the A-4 had been operational six months earlier it would have made the invasion “extremely difficult if not impossible”, Armaments Minister Speer took the view that “the enormous scientific and technical effort, together with the bottleneck caused in raw materials and fuels, prevented a large number of jet fighters being built instead”.
In the autumn of 1943 Otto Lafferenz, a director of the Deutsche Arbeitsfront, suggested to Peenemünde Weapons Testing Centre the building of a number of submersible containers, each holding a V-2 rocket. A U-boat would tow three of these 500-tonne barges, each 37 metres in length and 5.5 metres in diameter, underwater to the coast of the United States and, when within 300 kilometres of the target, flood the ballast tanks of the barge to bring it to an upright position projecting about 5 metres above the surface. This would allow the rocket to be fired from a gyroscopically stabilized platform.16
Trials were carried out with U-1063 and apparently similar experiments were conducted later at Lake Toplitz in the Austrian Alps when manned midget submarines practised firing rockets which resembled small-scale V-2s.17 A Kriegsmarine naval experimental station (CPVA) was located on the shore. The Lafferenz project was codenamed Teststand XII and Projekt Schwimmweste, and orders for the barges were placed with Stettiner Vulkanwerft and Schichau Werft Elbing in early December 1944.
It had been found in October 194318 that a U-boat towing a submerged barge had to maintain at least 4.1 knots through the water at periscope depth, for at 3.9 knots the barge lost the dynamic force necessary to hold it under. Various ideas were tried out unsuccessfully to reduce the minimum towing speed. As battery-propelled U-boats had insufficient capacity to proceed submerged at 4 knots for any length of time, and it was already dangerous enough in 1944 to voyage at normal speeds without also towing three barges, the Type XXI Elektro-boot was elected for the operation which involved a 30-day tow across the Atlantic at 12 knots. The time required on the surface for the operation does not seem to have been disclosed.
When the campaign began in earenest, scientists at Peenemünde had found out the hard way that a successful launch of the V-2 was virtually impossible four days or so after manufacture and a procedure known as heisse Semmel (hot dumplings) was in force on land whereby any V-2 to be used operationally was fired within three days of manufacture.19 Clearly a V-2 could not be fired after thirty days in a damp transatlantic barge and so the US idea was shelved. In early December 1944 orders were placed with Stettiner Vulkanwerft and Schichau Werft Elbing. It seems self-evident that there must have been a plan to use these barges to bring Britain under V-2 fire from the North Sea.
In 1946, the Deputy Commanding General of Army Air Force Intelligence, Lt-Gen Donald Leander Putt, told the Society of Aeronautical Engineers: “The Germans were preparing rocket surprises for the whole world in general and England in particular which would have, it is believed, changed the course of the war if the invasion had been postponed for so short a time as half a year.” Putt was also quoted in an aside as having stated that “the Germans had V-2s with atomic explosive warheads”. A surprise is a surprise and hitherto ordinary rocket warfare had proved unproductive. The range of the V-2 was 200 miles. The crucial success of the Allied progress by December 1944 had therefore been to drive the German forces in Europe beyond this limit. The objective of the Ardennes campaign was the Belgian port of Antwerp, 200 miles from London. It was served by a short rail connection from Germany and its recapture was essential for a renewed V-2 offensive. Furthermore it was immediately available as a U-boat and Lafferenz barge base. The A-9 “winged V-2” project was resurrected in 1944/45. German testimonies allege that at least one successful test launch was made from the Harz in March 1945, and in mass production this rocket could have hit London from central Germany.
The V-3
Few commentators seem to be in any doubt but that the V-3 was the “High Pressure Pump” or “England Gun”. Paul Brickhill recorded in The Dam Busters:
“the greatest nightmare of all was the great underworld being burrowed under a 20-foot-thick slab of ferro-concrete near Mimoyecques (between Calais and Boulogne). Here Hitler was preparing his V-3. Little has been told about the V-3, probably because we never found out much about it. The V-3 was the most secret and sinister of all – long-range guns with barrels 500 feet long!”
The V-3 was probably based on the 1885 unsuccessful ballistic principle of the Americans Lymann and Haskell and Baron von Pirquet’s concept of sequential, electrically activated, angled side chambers to provide additional velocity to a shell during its passage of an immensely long tube.
In mid-1942 August Cönders, chief engineer of the Röchling Iron and Steel Works, Leipzig, rediscovered the principle while reading through technical dossiers captured by the Germans in France in 1940. He worked out an improved design and approached Armaments Minister Speer with the idea. Hitler was enthusiastic and demanded that the development should proceed immediately.
The design was for a gun consisting of numerous lengths of smoothbore metal tubing bolted together to form a barrel up to 124 metres long. Every 3.65 metres along its length was a lateral combustion chamber set at from 45° to a right angle. The shell and main propellant were loaded into an sFH18 heav
y field howitzer breech. When the gun was fired, the projectile would be impelled forward by pressure from a gas cartridge, and on passing each chamber it triggered electrically another cartridge positioned there which gave the shell further velocity. This was repeated throughout its transit of the barrel. The electrical activation solved a detonation problem which had been caused by expanding gases detonating the auxiliary chambers before the arrival of the shell. The muzzle velocity was around 1500 metres/sec which was significantly greater than that of standard artillery and provided a range of about 160 kilometres. The original 10-inch calibre projectile was over nine feet in length and weighed 140 kilos with a 25-kilo warhead. Six wings opened in flight for stability. Twenty-five guns were projected which at full output would have enabled London, 150 kilometres distant, to be subjected to a persistent rain of up to 200 ten-inch calibre shells per hour. For this reason the project was nicknamed fleissiges Lieschen, Busy Lizzie. The Heereswaffenamt, or German Army Weapons Office, contracted with firms such as Skoda, Krupp, Röchling, Witkowitz Iron and Steel, Faserstoff, Fürstenberg and Bochumer Verein for various calibres of ammunition. Towards mid-1944 20,000 shells were completed or under production.
Even before the gun trials had begun, work was started in the late summer of 1943 on a vast, well camouflaged underground gun battery to house twenty-five barrels of the HPP on the Channel coast at Mimoyecques. The barrels were to be sunk in shafts at a 50° angle 150 feet down into the ground. A slave labour force of 10,000 persons was involved in the construction and information was soon passed to London about a new mammoth “underground V-1 site”.
The initial tests were carried out using barrel lengths between 50 and 130 metres, first at Hillersleben and then from a range at Misdroy near Peenemünde at the beginning of 1944. Various permutations of barrels and chambers were tried without much success. Shells were supplied by numerous manufacturers. In tests between 21 and 23 March 1944 it was found that at muzzle velocities above 1100 metres/sec the tubes lost stability and developed metal stresses. General Leeb recommended that the project be stopped for investigations. By May 1944 the gun had an acceptable range of 95 kilometres and experiments were stepped up to find ways of increasing muzzle velocity. Before any guns were delivered, the Mimoyecques emplacement was destroyed on 6 July 1944 by RAF aircraft using a 12,000-pound Tallboy bomb. This signalled the end of the project for the long-range bombardment of London and put the entire V-3 project in question.
Nevertheless further trials with the HPP with shorter barrels were undertaken at Misdroy and eventually the whole project was placed in the hands of SS-Obergruppenführer Hans Kammler, head of the V-weapons project. Under his supervision the V-3 project was accelerated for an operation in the late autumn of 1944 and, with the help of General Dr (Ing) Erich Dornberger, military commander at Peenemünde, a battery of two 50-metre long 15-cm (5.9-inch) calibre barrels with twelve right-angled side chambers was completed. An emplacement had been excavated at Bürderheidermühle on a wooded slope of the Ruwer at Lampaden, about 13 kilometres south-east of Trier, where the battery was installed under the supervision of Hauptmann Patzig and his 550-strong Army Artillery Detachment 705.
The two HPP barrels rested on thirteen steel girders anchored to buried wooden foundations and were laid to the west with a 34° elevation. 43 kilometres along the firing line was target number 305, Luxemburg City. Calculations showed that the two guns had a maximum range of 65 kilometres with a shell dispersion radius of from 2.5 to 5 kilometres.
Between the two barrels were three bunkers for the gun crews plus either side of the barrels ten smaller bunkers which served as shell and powder magazines.
The Lampaden emplacement was part of the plan for the Ardennes offensive. Ammunition supply was poor because of disruption to the railways and in view of the critical time factor it was decided to use a 95-kilo shell of 15-cm calibre with a warhead of 7 to 9 kilos. The propellant was a 5-kilo main cartridge and twenty-four additional chamber charges, a total of 73 kilos of Ammon powder per shell.
Neither gun was operational when the Ardennes offensive began on 16 December 1944. Hurried preparations were being made to support the German offensive from Lampaden. Luxemburg City, liberated by the Americans in September 1944, was finally chosen as the target for diversionary fire. Although the battery was only operational to a limited extent on 20 December, Kammler was told by High Command West to have it ready before New Year.
On Saturday 30 December 1944 No 1 Gun opened fire. The flight of shell from Lampaden to Luxemburg was 42.5 kilometres. Because of muzzle velocity variables and the variety of propellants being used it was estimated that the target zone was from 40.6 to 43.6 kilometres, giving a dispersal of salvoes of about 3 kilometres. The exact barrel elevation was set at 36° and the muzzle velocity 935 metres/second.
Two ‘warmers’ were fired at 2145 hrs and 2205 hrs before Oberleutnant Bortscheller ordered the gun to open fire in earnest at 2216 hrs in the presence of SS-Obergruppenführer Kammler, the battery commander and officers from a neighbouring artillery detachment. Fire ceased at 2343 hrs. Five shells exploded more or less in the city centre but what effect they had is unknown.
According to German sources, these were 95-kilo shells, probably the six-winged Röchling type numbered 32, 29, 47, 15, 28 (firing sequence). On 31 December twenty-three more were fired between 0007 hrs and 2333 hrs from No 1 Gun, while No 2 Gun was still being adjusted, this not being completed until 3 January.
Following round 17 fired at 0944 hrs the pressure tube was found to have shifted by 4 millimetres and had to be realigned. After two ‘warmers’ the remaining shells were fired without incident between 1943 and 1958 hrs.
4 January 1601–2007 hrs. No 1 Gun, 16 rounds. No 2 Gun ready but did not fire.
11 January 2016–2351 hrs. Both guns fired, total 20 rounds.
12 January 1847–2224 hrs. Both guns fired, total 20 rounds.
13 January 0757–1238 hrs. Both guns fired, total 22 rounds, after which both barrels were checked and adjusted. Because of ammunition shortage, fire was not resumed until 15 January.
15 January Early afternoon, six shells exploded in Luxemburg City.
16 January Late afternoon, six rounds fired. The tower of the cathedral was hit and four persons attending mass were killed.
18 January 1421–1638 hrs. Both guns fired 19 rounds. Most of these exploded north-east of the city in the suburbs of Clausen, Neudorf and Hamm injuring 13 persons.
20 January 0808–1353 hrs. Both guns fired a total of 24 rounds.
Preparations had been taken in hand to transport and mount two more barrels with selected lines of fire into Belgium and France and existing HPP ammunition was rationed out between the four guns. By now the Americans were counter-attacking successfully in the Ardennes region and as it was obvious that Lampaden would soon be under threat, Kammler ordered the detachment to be prepared to dismantle the two pressure tubes for a withdrawal east of the Rhine in due course. The lack of ammunition remained severe.
15 February 0908–1735 hrs. No 1 Gun fired 20 rounds at Luxemburg. These all fell in unpopulated areas near Hamm and Sandweiler east of the city.
16 February 1020–1405 hrs. No 1 Gun fired four shells which fell near Fetschenhaff causing little damage. According to German sources the battery had now only six rounds left.
22 February 1745–1858 hrs. Six shells were fired, all off-target and landed in open country near Merl. This terminated the V-3 programme and the guns were dismantled for transport across the Rhine.
On 26 February US armoured units advanced to within 3 kilometres of Lampaden where they captured guns and replacement parts. A quantity of ammunition was also confiscated and tested later at the Aberdeen Proving Ground, Maryland. The V-3 HPP was considered to have limited value and needed further development. Operationally 183 rounds had been fired from Lampaden towards Luxemburg of which 143 (78%) exploded within the territory or very close to it.20
The V-3 suffered from lack of developme
nt due to the pressure of time. Had the Mimoyecques battery been operational against London in 1943, delivering 200 6-inch shells per hour, Paul Brickhill’s fears might easily have been justified.
V-4 Uraniumbombe and the Doomsday Bomb
Hitler was pinning all his hopes on the Uraniumbombe. This laboratory-produced nuclear explosive was to be the warhead in the large V-2 or A9/10 rockets. The V-2 had a range of 200 miles while the A9/10 could hit New York. There was no rocket of the same species for the intermediate ranges and this omission was fatal. By December 1944 when the Uraniumbombe was ready for use in numbers for the definitive V-2 campaign, the Low Countries and France had been lost and now the range was too long. After the failure of the Ardennes campaign, in March 1945 Hitler decided on a last desperate gamble. On his last appearance at the front, he exhorted his troops to hold out until the miracle weapon should be ready, which would bring about the change in Germany’s fortunes. Posterity has been left few traces of the former flak weapon based on firedamp. In principle it generated a ferocious pressure wave at ground level, killing principally by blast and suffocation, but it had a knock-on effect which threatened a structural change to the atmosphere. The mysterious loss of Luftwaffe and OKW War Diaries for the month or so in question may have been connected with the execution of Luftwaffe General Barber and several hundred pilots and airfield commanders for refusing to implement orders to use it at the end of March 1945. When captured in May that year, Hermann Goering exclaimed that he had “declined to deploy a weapon which might have destroyed all civilisation,” the inference being perhaps that the use of the explosive threatened to so destabilize the climate as to bring about the cataclysm, but that Hitler had nevertheless ordered its use against the Allies on the Western Front regardless. It certainly does not look as though it happened that way round, for reasons explained later.
Hitler's Terror Weapons Page 3