Avalanche release through direct mechanical stress

The triggering of an avalanche by direct mechanical stress takes place differently than with the detonation of explosives or the ignition of a gas mixture solely with the local conditions. This method is consistently carried out by introducing an additional load into the unstable avalanche slope, which should trigger the avalanche.

skier

By driving a person into a potential avalanche slope, the skier should consciously cut into the unstable snow cover in an upper, alleged breaking zone ( ski cutting ) and trigger an avalanche. The method is very risky for the skier, even if the acting skier is secured or equipped with a rope or with an avalanche airbag or avalanche search device etc. and this is not a suitable method in terms of employee protection . In the European Union , the controlled triggering of avalanches must generally be carried out in such a way that the people involved can be guaranteed the greatest possible degree of safety when the avalanche is triggered.

In a Delphium question on the evaluation of avalanche protection measures (2003) on behalf of the forestry service for torrent and avalanche control , the triggering of snow slabs by stepping on skis on smaller slopes was still mentioned quite often as a method in addition to the common methods (about 3, 5% of the avalanche releases).

Snowcat

By one or more groomers larger snow masses are pushed into the avalanche starting zone, should be made so that the labile snow pack by the extremely heavy burden to slipping and is in turn caused an avalanche in a chain reaction. Depending on its consistency, snow weighs around 200 to 500 kg / m³, a large snowcat can move around 4 to 6 m³ of snow in one operation with the front shield. In principle, the system is only suitable where there is access for snow groomers at the upper point of the avalanche and there is a risk that when snow is transported over a ridge, broken cornices, a driving error on the part of the snow groomer, etc., the driver and the snow groomer in Tilt the avalanche slope.

Triggering by large amounts of snow is not always reliable, as the avalanche start zone does not always have to be near the ridge. This method is therefore only suitable for smaller, well-developed ski areas and for small slabs.

In the above-mentioned Delphium question on the evaluation of avalanche protection measures (2003), pushing snow or guarding with piste machines into steep slopes was also mentioned relatively often as a method - in addition to the common ones - for triggering avalanches (about 3% of avalanche triggering).

Avalanche tilting table

A Lawinenkipptisch (only: tilting table , engl. : Tilting table ) is a permanently erected and located in a place mechanical design, with a relevant mass of snow is tilted in the starting zone of the avalanche and thereby to be caused to slipping the labile snowpack , which should create an avalanche in a chain reaction.

ARE ( Avalanche Releasing Equipment , Vienna) developed an avalanche tilting table with lifting cushions (about seven meters long and about 2.5 wide). The tilting table must be installed near the known starting zone of an avalanche before the winter season. If necessary, the lifting bag is filled with nitrogen , which pushes the upper steel cover of the construction in which the lifting bag is located upwards with around 10 tons. Subsequently, the mass of snow on the tilting table, which is tipped into the avalanche start zone, is supposed to trigger an avalanche. The cost of the system should be around 40,000 euros. The device is powered by fuel cells and the nitrogen supply in the device should be sufficient for a year. The tilting table is triggered via a radio command.

Vibrating table

Attempts to trigger avalanches with large vibrating tables in the avalanche starting zone did not get beyond the project stage.

Individual proof

↑ Variant skiers or ski tourers usually trigger avalanches without the will (unintentionally) to do so.
↑ Anton Kaindl: Raurißer shoot the avalanches with a cannon from the mountain , Salzburger Nachrichten of January 13, 2017.
↑ Stefanie Buchinger: Artificial triggering of slab avalanches - comparison of the methods used in Austria, master's thesis, University of Natural Resources and Life Sciences, Vienna 2014, p. 56.
^ Section Vorarlberg, WLS REPORT 83 , Vienna in October 2003, pp. 33 and 157. This was a worldwide survey in which the answers of experts from the Alps, the Carpathians and the Rocky Mountains were evaluated.
↑ Avalanche release by gas mixture ignition and avalanche release by explosives .
^ WLS Report 84 , University of Natural Resources and Life Sciences, Vienna, Institute for Alpine Natural Hazards and Forest Engineering, Vienna in May 2003, p. 69.
^ ^A ^b Hans-Gustav Olshausen (ed.): VDI-Lexikon Bauingenieurwesen , VDI-Gesellschaft Bautechnik, Düsseldorf 1991, Springer Verlag, ISBN 978-3-662-30425-9 , p. 341 google books .
^ Peter Höller: Interalpin 2009 in Innsbruck , website of the Federal Research Center for Forests in Austria.
↑ ARE Avalanche Releasing Equipment , website of the Federal Research Center for Forests in Austria.

[1] Variant skiers or ski tourers usually trigger avalanches without the will (unintentionally) to do so.

[2] Anton Kaindl: Raurißer shoot the avalanches with a cannon from the mountain , Salzburger Nachrichten of January 13, 2017.

[3] Stefanie Buchinger: Artificial triggering of slab avalanches - comparison of the methods used in Austria, master's thesis, University of Natural Resources and Life Sciences, Vienna 2014, p. 56.

[4] Section Vorarlberg, WLS REPORT 83 , Vienna in October 2003, pp. 33 and 157. This was a worldwide survey in which the answers of experts from the Alps, the Carpathians and the Rocky Mountains were evaluated.

[5] Avalanche release by gas mixture ignition and avalanche release by explosives .

[6] WLS Report 84 , University of Natural Resources and Life Sciences, Vienna, Institute for Alpine Natural Hazards and Forest Engineering, Vienna in May 2003, p. 69.

[Olshausen-7] A ^b Hans-Gustav Olshausen (ed.): VDI-Lexikon Bauingenieurwesen , VDI-Gesellschaft Bautechnik, Düsseldorf 1991, Springer Verlag, ISBN 978-3-662-30425-9 , p. 341 google books .

[8] Peter Höller: Interalpin 2009 in Innsbruck , website of the Federal Research Center for Forests in Austria.

[9] ARE Avalanche Releasing Equipment , website of the Federal Research Center for Forests in Austria.