Blasting for safety
Avalanche - blasting towers ensur safe and clear roads in Sölden
Venter Landestraße, a main road near Sölden (Austria), had to be closed due to avalanche hazard more than twenty times last year, causing economic damages and dissatisfaction among residents. But since INAUEN-SCHÄTTI avalanche-blasting towers were installed to safeguard the road, the sign “Road open!” is up with increasing frequency
INAUEN-SCHÄTTI installed a combined tower equipped with both the Avalanche Guard (left) and the Avalanche Master (right) in Sölden for the first time. Photo: Inauen -Schätti
The 14-kilometer-long Venter Landesstraße winds between Sölden and Vent through the rough terrain of the Ötztaler Alps (Austria). Though the mountain side has been secured with expensive fences for a long time, the open end has hardly been secured at all. As a result it often saw closures, night-time clearances and dangerous situations. “Wet snow avalanches were unforeseeable especially during spring time.
Even at the lowest alert level 1 uncontrollable avalanches occurred at the most unusual times,” says Franz-Josef Fiegl, Head of the Sölden municipality building office. The local Avalanche Commission had to close Venter Landestraße more than twenty times a year. An unbearable situation that the municipality decided to mitigate in cooperation with the Province of Tyrol and the planning office SYNALP.
Because avalanche fences as a classical protective measure are expensive and necessarily interfere with the natural environment, the responsible parties decided to build seven avalanche-blasting towers, including an avalanche radar, a weather station, explosives repository, and safety accessories such as shut-off barriers and grilles. Altogether, 1,000 meters of the main road was secured.
Uncontrollable avalanches belong to the past. Photo: Sölden Municipality
Inexpensive, safe and environment-friendly
“In terms of the investment volume, this alternative’s cost of one million euros was significantly less expensive than a one-kilometer-long fence would be - 10.6 million euros,” compares Fiegl. The maintenance cost, too, is lower, and the impact on the environment less acute. But the main plus is the safety provided by the avalanche towers: detonation charges are either dropped by rope (the Avalanche Master) or shot into the snow pack (the Avalanche Guard). The goal is always to trigger an avalanche in a controlled way. “We can now remove snow masses from the slopes regularly and prevent the risk of large, uncontrollable avalanches,” adds Fiegl contentedly.
Franz-Josef Fiegl, Head of Building Office, Sölden
“Thanks to the INAUEN-SCHÄTTI avalanche-blasting installations, there are significantly fewer road closures and we have better information about the snow conditions than in the past. By repeated detonations of small snow masses we prevent large uncontrollable avalanches and road blockages. The Avalanche Master and the Avalanche Guard are also much less expensive than, for example, classic protective measures such as fences and they interfere less with the natural environment. Last but not least, we like our towers because they enable highly safe remote-controlled detonations.”
Comfortable triggering via the internet
Another advantage is that the avalanche triggering can be controlled remotely. “The customer can comfortably control detonation charges via the internet – provided that he has our software, the password and the detonation code,” explains Jürg Knobel from the manufacturer Inauen -Schätti . Dangerous hand-dropped blasting operations in rough terrain or costly and time- and weather-dependent helicopter blasting are no longer necessary – a smartphone or a PC is all that is needed.
Lediglich drei Flugstunden benötigten die Hubschrauber bei der Montage der sieben Sprengmasten. Foto: Inauen-Schätti
Assembly in just two days
The assembly of the seven towers in Sölden took only two days – one of the reasons why the responsible parties chose INAUEN-SCHÄTTI. “INAUEN-SCHÄTTI provided a detailed, work-intensive offer already in the uncertain early stages of the project. They continue to look after us, e.g. train our staff or help us re-charge the towers,” reports Fiegl. In addition, with around 30 avalanche-blasting installations in the ski area Sölden, they have great references from the region and – unlike their competitors – they never permit live ammunition to be transported by helicopter.
Considerably fewer road closures
However, the best argument in favor of INAUEN-SCHÄTTI avalanche-blasting towers is their effectiveness. Fiegl reports: “We have already fired 40 out of 80 charges in the first half of this season – and with success. The number of road closures has dropped significantly, snow clearance with the help of diggers and trucks belongs to the past. Thanks to the data collected by the towers and the avalanche radar, we are much better informed about the behavior of the snow pack.” ts