Zippermeyer Wirbelwind Kanone.

Dr. Mario Zippermayr, an eccentric Austrian inventor working at an experimental establishment at Lofer in the Tyrol, designed and built a series of highly unorthodox anti-aircraft weapons that were observed very closely by the Reichsluftfahrtamt (Office of Aeronautics) in Berlin. Due to the overwhelming numerical air superiority of the Allies every effort was made during the last year of the war to find ways of exploiting any known phenomenon that could bring down the heavy bombers of the USAAF and RAF. Dr. Zippermayr constructed both a huge Wirbelwind Kanone (Whirlwind Cannon) and Turbulenz Kanone (Vortex Cannon). Both had the same goal – to knock down enemy bombers through clever manipulation of air.

To achieve this, the “Wind Cannon” used a detonation of hydrogen and oxygen to form a highly compressed plug of air that was channeled through a long tube that was bent at an angle and fired like a shell towards enemy aircraft. Impossible as this may seem the Wind Cannon did particularly well on the ground – breaking one inch thick wooden boards from a range of 200 yards! This promising development, however, meant nothing against the Allied bombers that were flying at 20,000 ft! Nevertheless, taken from the Hillersleben Proving Grounds the Wind Cannon was used in defense of a bridge over the Elbe River in 1945. Either there were no aircraft present or the cannon had no effect because it was still intact where it was found.

The Turbulenz Kanone, by comparison, was a large caliber mortar sunk into the ground with fired coal dust and slow burning explosive shells to create an artificial vortex. This also worked well on the ground but again the problem was the same – how to generate a large enough effect to reach the aircraft. Zippermayr did not know if the pressure changes of this device would be sufficient to cause structural damage to an aircraft but the vortex would definitely have an effect on the wing loading as even clear air turbulence had brought down civilian airliners.

Even though Zippermayr could not make either of these weapons any more potent, three outcomes came from his research. The first was the coal dust shell application used with light artillery in the Warsaw Ghetto which involved nothing more than shortening the barrel of the artillery piece and detonating the shells in flight. The improvised weapon was named “Pandora” and was sadly used to deadly effect against the Jewish freedom fighters.

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A special catalyst had been developed by the SS in 1943 and the following year Zippermayer turned his energies to a heavy air (Schwere Luft) bomb. Encouraging results were obtained from a mixture consisting of 60% finely powdered dry brown coal and 40% liquid air. The first trials were carried out on the Döberitz grounds near Berlin using a charge of about 8 kg powder in a tin of thin plate. The liquid air was poured on to the powder and the two were mixed together with a long wooden stirrer. The team then retired and after ignition everything living and trees within a radius of 500 to 600 metres were destroyed. Beyond that radius the explosion started to rise and only the tops of trees were affected, although the explosion was intense over a radius of 2 kilometres.

Zippermayer then conceived the idea that the effect might be improved if the powder was spread out in the form of a cloud before ignition, and trials were run using an impregated paper container. This involved the use of a waxy substance. A metal cylinder was attached to the lower end of the paper container and hit the ground first, dispersing the powder. After 0.25 seconds a small charge in the metal cylinder exploded, igniting the funnel-shaped cloud of coal dust and liquid air.

The ordnance had to be filled immediately prior to the delivery aircraft taking off. Bombs of 25 kgs and 50 kgs were dropped on the Starbergersee and photographs taken. SS-Standartenführer Klumm showed these to Brandt, Himmler’s personal adviser. The intensive explosion covered a radius of 4 kilometres and the explosion was felt at a radius of 12.5 kilometres. When the bomb was dropped on an airfield, destruction was caused as far as 12 kilometres away, although only the tops of trees were destroyed at that distance, but the blast flattened trees on a hillside 5 kilometres away.

These findings appear in the British Intelligence Objectives Sub-Committee Final Report No 142 Information Obtained From Targets of Opportunity in the Sonthofen Area. Although one suspects initially that the radius of the area allegedly affected as described in this report had been worked upon by the Propaganda Ministry, the fact is that this bomb is never heard of today. Furthermore British Intelligence published the report without comment and what tends to give the description weight is the fact that the Luftwaffe wanted aircrews flying operationally with the bomb to have knowingly volunteered for suicide missions. The idea that the bomb had unusual effects was hinted at not only by the head of the SS-weapons test establishment but also possibly by Goering and Renato Vesco. On 7 May 1945 in American custody, Goering told his captors, “I declined to use a weapon which might have destroyed all civilization”. Since nobody knew what he meant, it was reported quite openly at the time. The atom bomb was not under his control, although the Zippermayer bomb was. Vesco reported that the supreme explosive was “a blue cloud based on firedamp” which had initially been thought of “in the anti-aircraft role”. On the Allied side, Sir William Stephenson, the head of the British Security Coordination intelligence mission stated:

“One of our agents brought out for BSC a report, sealed and stamped This is of Particular Secrecy telling of liquid air bombs being developed in Germany of terrific destructive power.”

A 50 kg bomb was said to create a massive pressure wave and tornado effect over a radius of 4 kms from the impact point, a 250 kg bomb for up to ten kms. A sequential disturbance in climate for a period after the explosion was reported. Radioactive material added to the explosive mixture was possibly to give it even better penetration and distribution. Zippermayer’s device fits the idea of a high pressure bomb which Professor Heisenberg seemed to know about and to which he alluded in his eavesdropped conversation at Farm Hall. The bomb would have been the equivalent of a tornado but covering a far wider diameter, sucking up in its path everything but the most solid structures and scattering radioactive particles over the wide area devastated by the initial explosion. The survivors of the explosion would be suffocated by the lightning effect at ground level burning up the surrounding air.

The head of the SS-Weapons Testing Establishment attached to the Skoda Works was involved in the destruction of the catalyst at the war’s end. He had personally witnessed it being tested at Kiesgrube near Stechowitz on the Czech-Austrian border. These must have been the first tests, since he describes the astonishment of the observers at the force of the blast and tornado effect. Various other smaller tests were carried out at Fellhorn, Eggenalm and Ausslandsalm in the Alps. After these a larger experiment was made at Grafenwöhr in Bavaria described by the SS-General in the following terms: “We were in well-constructed shelters two kilometres from the test material. Not a large amount, but what power -equal to 560 tonnes of dynamite. Within a radius of 1200 metres dogs, cats and goats had been put in the open or below the ground in dug-outs. I have seen many explosions, the biggest in 1917 when we blew up a French trench complex with 300,000 tonnes of dynamite, but what I experienced from this small quantity was fearsome. It was a roaring, thundering, screaming monster with lightning flashes in waves. Borne on something like a hurricane there came heat so fierce that it threatened to suffocate us. All the animals both above and below ground were dead. The ground trembled, a tremendous wind swept through our shelter, there was a great rumbling, everywhere a screeching chaos. The ground was black and charred. Once the explosive effects were gone I felt the heat within my body and a strange numbness overcame me. My throat seemed sealed off and thought I was going to suffocate. My eyes were flickering, there was a thundering and a roaring in my ears, I tried to open my eyes but the lids were too heavy. I wanted to get up but languor prevented me.” An area of 2 kilometres was utterly devastated. Several observers on the perimeter were seriously affected by the shock wave and appeared to suffer from a kind of intoxication effect which lasted for about four weeks. That the weapon failed to make its debut on the battlefield in 1943 arouses the suspicion that very real fears existed regarding its knock-on effect on the climate. Within sight of Gernany’s defeat, it was tested again at Ohrdruf in the Harz in early March 1945.