Avalanche guard
The Avalanche Guard (formerly also: Avalanche Organ ) is a permanently installed throwing system for explosives to trigger avalanches , made by the Swiss manufacturer Inauen-Schätti AG. In contrast to the explosive mast / avalanche mast , the charges with the avalanche monitor are ejected up to 200 meters. The area of action of the avalanche guard is up to 400 meters. In practice, a throwing distance of around 130 to 150 meters or an effective zone of 260 to 300 meters are realistic.
Avalanche monitors have been offered since 1996.
function
The ten pipes in the launching system directly take the explosive cartridges (e.g. Riomon T1) and are ejected individually from the pipes by a black powder propellant ( pyrotechnic ). When it is ejected from the tubes, two detonators are pulled and the safety cord attached to them is ignited (redundant ignition). The throwing range is varied with the amount of the discharge charge in relation to the weight of the explosive cartridge. The throwing distance is a maximum of 200 meters for an explosive cartridge of 2.5 kg, and a maximum of 50 meters for a 5 kg explosive cartridge. In Austria , the avalanche monitor is loaded with explosive cartridges up to 2.5 or 5 kg , in Switzerland up to 2.7 or 5.4 kg per tube. The Avalanche Guard previously to predetermined targets (demolition zones of avalanches ) injected (set) and can therefore be operated without visual contact and in bad weather.
The throwing distance varies over the course of a winter as the black powder used as a propellant ages due to drying out.
An avalanche guard can trigger an avalanche explosion in a sequence of around 2 to 4 minutes. The components of a charge used in addition to the explosives to be launched from the avalanche guard consist almost entirely of rotable material such as z. B. wood. Each load is equipped with a RECCO strip to make it easier to find failures, as it is possible for a failure ( dud ) to slip on the snow cover. As with manual avalanche blasting, this is a disadvantage of this system, as it would be optimal if the explosive charge detonated 0.5 to 3 meters above the snow cover in order to fully exploit the detonation pressure.
The energy supply for the avalanche monitor is self-sufficient via photovoltaic modules .
Operation and release
In Austria and Switzerland, the operation of the permanently installed system requires special additional training for those authorized to blast . Just initial schooling is insufficient.
The charges are triggered remotely from a PC , smartphone or tablet via a radio link or a GSM network or GPRS connection and special software. The software enables secure access, permanent monitoring of the system, ignition and triggering of an avalanche. The detonation is reported back via a geophone .
The charges of the avalanche monitor ignite on the snow cover. For the trigger point height, explosives and the amount of explosives as well as the ignition of the explosives, see: Avalanche triggering by explosives and artificial avalanche triggering .
further explanation
An avalanche monitor can also be operated with an explosive mast / avalanche mast on the same foundation . Likewise, two launch systems with ten pipes each can be operated in different orientations on the same foundation.
An individually operated launch tube using the same system is known as an avalanche whistle .
costs
The acquisition costs for an avalanche guard are around 10,000 euros per launch tube, each shot itself costs around 60 to 100 euros (excluding expenses for the operating team, barrier posts, etc.). The costs for a foundation are given as around 5,000 to 10,000 euros. Added to this are the annual maintenance costs.
See also
- List of avalanche accidents , list of avalanches and landslides, landslides and list of disasters
- Search for avalanche victims , avalanche shovel and avalanche cord
Web links
Individual proof
- ↑ This is what the Doppelmayr company from Wolfurt called the throwing system as long as it was in charge of sales.
- ↑ The effective zone is the circular area around the detonation point within which the additional pollution generated has a certain minimum size. Effective zones are used for assessing negative explosions (“Which area was tested by the explosion?”) And for developing safety concepts (Lukas Stoffel [1] ).
- ↑ Lukas Stoffel: Comparison of the blasting methods: Gazex, Avalanche Guard / Mast Inauen-Schätti, Wyssen Sprengmast, Avalancheur , Comparison of methods for artificial avalanche release, WSL Institute for Snow and Avalanche Research SLF, January 24, 2013, p. 7 f.