Avalanche detonator
The avalanche detonation mast (also: avalanche mast or Sprengmast ) is a permanently installed dropping system for explosives to trigger avalanches on steep slopes. In contrast to the avalanche monitor or the avalanche whistle , the explosive cartridges with the avalanche detonator are not ejected up to 200 meters, but after ejection hang on a tether under the approximately 8 meter high and 25 ° inclined mast. This has the advantage that the blasting takes place in the optimal area above the snow cover and the explosive cartridge cannot slide off the snow cover.
Avalanche detonators have been offered since 2000.
Installation and function
An avalanche detonation mast is installed at an angle of about 25 ° in the known starting zone of an avalanche and, if necessary, the explosive charges are ejected from the magazine and detonated. Depending on the manufacturer, there is space for between four and 36 ready-made explosive charges in a magazine of the avalanche detonation tower. When it is ejected from the magazine, two detonators are pulled and the safety cord attached to them is ignited (redundant ignition). In Austria , the avalanche detonator - depending on the manufacturer - is loaded with explosive cartridges up to 2.5 or 5.0 kg per magazine space in Switzerland up to 2.7 or 5.4 kg. The avalanche tower can also be operated without visual contact with the trigger point and in bad weather.
With an avalanche detonation tower, the explosive charge detonates optimally 0.5 to 3 meters above the snow cover and fully exploits the detonation pressure. The detonation height above the snow cover can be variably adjusted in advance with the length of the tether. Further advantages are (slightly different depending on the manufacturer):
- low construction costs
- no leads required
- no personnel in danger zone
- Quick access through remote triggering
- Independent of weather and time
- very little interference with the environment is required.
Disadvantages of the system are that there is always the same trigger point for the detonation and the high acquisition costs.
The energy supply of the avalanche tower 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 thus the triggering of an avalanche.
The charges from the avalanche tower ignite above 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 .
Triggering sequence: Trigger command - magazine releases a load - dropping of a load (secured on the tether) - explosion after about 30 to 40 seconds - detonation is displayed on the PC / smartphone / tablet - release of the tether - magazine closes automatically.
further explanation
An avalanche tower can also be operated with an avalanche monitor on the same foundation .
From the company Inauen-Schätti AG z. B. an avalanche detonation mast under the designation: Avalanche Trigger LM32 and similarly also offered by the Wyssen company, in which the dropping system (head part of the avalanche detonation mast) can be removed or used by helicopter from the mast without ground personnel, which gives direct access to the Dropping system is no longer required. The LM 32 is only activated by a magnetic switch when it is inserted in its holder. During the flight with the helicopter, the LM32 system is deactivated. The LM32 can hold 16, 24 or 32 explosive cartridges up to 5 kg, the Wyssen system can accommodate a maximum of 12 explosive cartridges, depending on the version.
costs
The cost of an avalanche detonation mast is around 100,000 euros, each blast itself costs around 100 euros (excluding expenses for the operating team, barrier posts, etc.). The costs for a foundation are given as around 12,000 to 25,000 euros. Added to this are the annual maintenance costs.
Detection
In the case of permanently installed devices, a geophone or microphone built into the device measures and displays whether the ignition and the success of the triggering of the avalanche occurred .
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
- ^ Samuel Wyssen: Artificial avalanche release , lecture by Wyssen, Innsbruck 2010.
- ↑ Siegele: Experience with temporary protective measures in Ischgl project Großtal - Hoher Zug .
- ↑ Lukas Stoffel: Comparison of the blasting methods: Gazex, avalanche detonation mast / mast Inauen-Schätti, Wyssen detonation mast, Avalancheur , comparison of methods for artificial avalanche release, WSL Institute for Snow and Avalanche Research SLF, January 24, 2013, p. 11 ff.