Item: GAZ-EX Avalanche Control System
Title: GAZ-EX Avalanche Control System
Proceedings: Proceedings of the 1994 International Snow Science Workshop, Snowbird, Utah, USA
- Jacob Scbippers [ T.A.S. (Technologle Alpine de securite SA.), Z.A. le Bresson, 38660 Ie Touvet, France ]
Abstract: To avoid some of the drawbacks associated with more traditional methods, I wanted to develop a system that would allow explosives to be stored all through the winter at the avalanche control device site. Additionally, I wanted a system that would work effectively with remote controls, that could be operated safety and easily accessed from a road or railway, from power stations, from the center of a resort area, etc. I worked on a lot of different options and possibilities, both in design and system components. In most countries, it is against the law to store explosives without following strict security measures. In place of explosives, we could use propane gas --it is not classified on the explosives list-- and it has many of the qualities we needed, including having higher power than explosives on powder snow and the noise of the explosion is usually quieter than more traditional methods. After a lot of trial and error (like blowing a plastic bag with an explosive mixture), I had the idea of using a metal tube with the power generated by ignition at the base of the tube and exploding the gas out of the open end. The inertia of the gas explosion out through the end of the tube against the snow surface --at least 30° slope-- causes it to slide with a path up to 60 feet in width. The hemispherical expansion creates a shock wave, effectively releasing any avalanche prone snow. The force of the explosion can be regulated at the remote base by controlling the amount of gas/oxygen mixture sent to the exploder. We tested many possibilities on the mountains in the snow. We measured air pressures resulting from the gas explosions --with Cemagref assistance-- and experimented with many different gases and combinations. A mixture of propane and oxygen finally appeared to be the most efficient. The test results and our operational experience clearly confirm that the shock wave resulting from a GAZ·EX explosion is longer than an explosive detonation shock wave, giving much better avalanche control: - just I Kg of gas is needed to produce the same shock wave as 8 Kg of TNT (about 25 mb) - a single 1.5 cubic meter GAZ-EX installation, at 7500 ft elevation, is equivalent to 15 Kg of TNT !
Language of Article: English
Keywords: gazex, bomb-tram, explosives
Digital Abstract Not Available