Like the Vortex Gun, the Wind Cannon was also developed by a factory in Stuttgart during the war. It was a type of gun that would eject a jet of compressed air against enemy aircraft. It was a strange device consisted of a large angled barrel like a bent arm resting in an immense cradle like some enormous broken pea-shooter lying askew. The cannon worked by the ignition of critical mixtures of hydrogen and oxygen in molecular proportions as near as possible. The powerful explosion triggered off a rapidly-ejected projectile of compressed air and water vapor, which, like a solid “shot” of air, was as effective as a small shell. Experimental trials of the cannon at Hillersleben demonstrated that a 25mm-thick wooden board could be broken at a distance of 200m. Nitrogen peroxide was deployed in some of the experiments so that the brown color would allow the path and destination of the otherwise transparent projectile to be observed and photographed. The tests proved that a powerful region of compressed and high-velocity air could be deployed with sufficient force to inflict some damage. However, the aerodynamics of a flying aircraft would almost surely neutralized the effectiveness of this cannon. In addition the effects of the cannon on a fast-flying aircraft was quite different from that on a fixed ground target. Still, the cannon was installed on a bridge over the Elbe, but with no significant results — either because there were no aircraft or simply no successes (as one might suspect). The wind cannon was an interesting experiment but a practical failure.
The first documented occurrence of the development of a weapon using abrupt changes in pressure goes back to the Wunderwaffen, literally “wonder weapons”-the name given by the Ministry of Propaganda to the experimental weapons program of the Third Reich. Shortly before the Nazi surrender, American Major General Leslie E. Simon was sent with others to Germany to lead an inquiry into the program. He would publish his observations in 1947 under the title German Research in World War II.
He mentions in particular that under the authority of Albert Speer, then minister of armaments, a research center situated near Lofer, Austria, worked “to duplicate in miniature the effects of tornados” thanks to a vortex cannon. The vortex is a (natural or artificial) phenomenon that takes the form of a whirlwind in which the moving particles (air, water) wrap in a spiral around a zone of low pressure. To produce a vortex in a controlled manner, Dr. Zippermeyer, who was responsible for this research, used a mortar set in the ground, which launched a projectile filled with carbon powder and a weak explosive charge. Once in the air, according to the scientist, the powder explodes and a vortex is created if the projectile is moving at a speed of at least several hundred meters per second. The idea was to be able to “remove the wings” of planes, which would be unable to sustain the resulting pressure differential. Simon indicates that “he achieved a considerable vortex effect,” but he doesn’t mention any use of the cannon other than an experimental one. Another prototype was developed by a company in Stuttgart: a “wind gun” aiming to shoot a “plug of air” at an airplane to destroy it. A model of this cannon projecting air by means of a mix of oxygen and hydrogen was found at the test center in Hillersleben. The Germans working on-site announced that the device could “break one-inch boards at a range of 200 meters but it produced no appreciable effect on aircraft at normal ranges.” It failed to ensure the anti-aircraft defense of a bridge on the Elbe.
Vortex weapons were the subject of major research in the twentieth century, not only in Germany but also in the Soviet Union and in the United States. It is not just the kinetic energy of the vortex, its power of impact, that interests researchers and military folks, but also the fact that its centrifugal force allows it to transport other particles. No weapon seems to have moved beyond the prototype stage. During World War II, the American inventor Thomas Shelton worked on resolving the problem of the unpredictability of combat gases, which a strong breeze can send back toward those who launch them. He developed a device that propels a vortex of noxious gas, which can thereby transport the poison over long distances. The prototype “sent a 45-cm smoke ring a distance of 50 meters with an `eerie howling sound.’ It would never be used.
In the early 1970s, the United States showed particular interest in developing “vortex rings and wind-generation machines” for “crowd and mob control,” but no known result emerged. In 1996, Dr. Andrew Wortman of a company called Istar proposed the development of a “vortex ring generator” with the same goal, but the army did not pursue the research “because it required fielding an entirely new system, and the trend in the Army was to reduce weight and logistic costs.” In 1997, ARL and ARDEC began to recycle and proposed adding a “kit” to the MK19-3 grenade launcher, which would provide “a means of quickly converting the Navy MK19-3 automatic 40-mm grenade launcher between lethal and nonlethal modes of operation” and allow it to shoot not only grenades but also gas vortices transporting chemical products. In the end, it was concluded “the kit enables the weapon to apply flash, concussion, vortex ring impacts, marker dyes, and malodorous pulses onto a target at frequencies approaching the resonance of human body parts,” but “gaps in technology . . . inhibit fielding.” In terms of developing “non-lethal” weapons, that same year the JNLWD launched a dedicated program, the Vortex Ring Gun Program, still with ARL. It was an ambitious project:
“The Vortex Ring Gun (VRG) program will design, build, and successfully demonstrate the capability to produce combustion-driven, ring vortices that will deter and disorient hostile individuals or crowds.”
Once again, a combination of the vortex with other effects was envisaged:
Applications could include an ability to mark an individual or object with a fluorescing dye at a distance; delivery of an incapacitating agent at a distance; delivery of aerosol at a distance (a chemical to corrode, lock, or otherwise disable an automobile); or temporarily introducing a smoke screen or obscuring agent. But the research was not “satisfying”: a stop was put to the program in 1998 due to the “unpredictable vortices and limits on effective range.”
Nonetheless, the enthusiasm didn’t abate. Five years later, British researchers Neil Davison and Nick Lewer reported:
An acoustic technology receiving considerable R&D attention is the vortex generator. . . . At the 2nd European Symposium on Non-Lethal Weapons in 2003 several groups presented on this topic. These included papers by The Defence Science and Technology Laboratory (DSTL) of the U. K. Ministry of Defence on “Initial Simulations of a Single Shot Vortex Gun,” Bauman Moscow State Technical University reported research on “Application of Vortex Technologies for Crowd Control,” and the Fraunhofer Institute of Chemical Technology (ICT) presented a paper entitled “Impulse Transport by Propagating Vortex Rings-Simulation and Experiment.”
In 2004, Canada showed a certain interest in vortex weapons in a report on “non-lethal” weapons. And in 2006, even though the research had been interrupted officially eight years prior in the United States, SARA’s website still boasted the merits of its vortex weapon: “A supersonic vortex of air hits its target at about half the speed of sound with enough force to knock them off balance. The vortex feels like having a bucket of ice water thrown into your chest.” Despite its capabilities, the weapon does not seem to have been used and has since disappeared from the company’s website.