Wyssen Avalanche Case Study

Ever present threat

For communities living in snowy mountainous regions of the world, avalanches represent an ever present danger for a significant portion of the year, threatening transport links, settlements and also sport enthusiasts who visit the mountains in winter. As many of these areas become more densely populated and the economic return from recreational activities fundamental, it has become vital that the threat from avalanche damage is understood and minimised. A knowledge of avalanche mechanics and behaviour is essential in planning future infrastructure developments and in the protection of those already in existence. In areas heavily reliant on snow season tourism, safety and the wellbeing of visitors is vital to economic growth. Approximately 100 lives are lost annually in the European alps due to avalanche related disasters, understanding the risks is key to managing and minimising the threat avalanche events pose.

Avalanche formation

Avalanches occur when snow deposited on a slope becomes detached and moves down the slope due to gravitational force. They generally happen when fresh snowfall cannot properly bond with the underlying layer upon which it falls and a lateral fracture begins to develop within the snow pack. Once the new top layer exceeds a critical mass, the load becomes too great for the fragile bonds to hold and areas of surface snow break free and begin their downward plunge. Within a few seconds large sections of a slope can be in motion, gathering speed as they break up and hurtle downslope, moving ever faster. Dry slab avalanches, which mainly move with a sliding motion, reach speeds of 50 to 100 km per hour but if it falls over very steep terrain a dry slab avalanche can become a powder avalanche which travels at speeds of 200 – 300 km/h.

One of the main problems is that these fault lines in the snow pack may lie beneath the snow surface for days or even weeks after a snowfall, with the lower layers of compacted snow just able to support the load of the snow above. The passage of a single skier may be all it takes to strain the bonds beyond cohesion and trigger the slide, unfortunately often burying and suffocating the unfortunate sportsperson.

Artificial triggering

The use of explosive charges to selectively release precariously packed snow has become the norm, with the resulting frequent, small avalanches being far safer than one eventual huge one. In some countries this procedure is performed by personnel using military munitions to trigger avalanches through rocket and mortar launches at the snowpack. However, in more populous areas this is forbidden or very strictly controlled. Dropping charges from a helicopter is another option but this is difficult in bad weather and impossible at night, as well as being costly and time consuming. The risk to any person or team having to move into an avalanche area to physically deploy such a device is obvious, so a remotely operated system offers the perfect solution.

Wyssen avalanche control

Based in Reichenbach im Kandertal, an idyllic Swiss valley nestled at the foot of the Alps is Wyssen Avalanche Control. This family business started nearly a century ago when Jakob Wyssen, a sawmill owner, realised a safer system was needed to manage logging and timber control on the slopes. He invented the skyline crane and his company grew to become world leader in cableway manufacture and installation.

In 2000, expanding on the firm’s development of a bomb tramway to enable delivery of explosive devices to areas at risk from avalanche, Jakob’s grandson, Sam founded the division of Wyssen AG that specialises in avalanche control. The development of the Wyssen Avalanche Tower was a key point in the company’s evolution and provides the foundation, literally, for their cutting edge avalanche detection and triggering system. Within 5 years of unveiling their invention, the company had become the market leader in Switzerland, Austria and Norway.

The avalanche control system

Wyssens’ avalanche control system offers a range of possibilities in avalanche surveillance and provocation. The “eyes” of the system are provided by doppler radar beacons situated where they can monitor a single or multiple neighbouring avalanche zones. Both a short range (SARA) and long range (LARA) version are available.

The short range radar has a range of 300-500m and ideally is focussed on a single location. A small, light device, it is fitted to the same tower that houses and drops the explosive charges. Powered by solar panels and batteries in the tower, the SARAs are only active for short intervals, usually functioning when the tower they are situated on is also in operation. Their main purpose is to provide feedback around the moment of avalanche triggering. The LARA system has a greater range of up to 2000m, with various power options available, this device can monitor a wider area. This means that they are placed facing the area of interest and are particularly effective in providing an alarm once movement is detected and at monitoring the extent of the avalanche flow.

Avalanches emit infrasound, which, although inaudible to the human ear, can be electronically detected by sensors and at a great distance. Wyssen Avalanche Control use a sophisticated algorithm and a specific arrangement of sensors to provide an early warning of increasing avalanche activity in a given area.

When planning a pre-emptive triggering, it is vital to know that the area where the snow slide is expected is free of human activity. It is quite probable that the avalanche may be triggered in bad weather when visibility is poor, so the use of a radar based, people spotting system, provides the ideal solution. Wyssen’s PETRA system is a doppler radar positioned so that it will monitor slopes for the appearance of humans in the danger zone, usually coupled with an optical or thermal imaging camera to enable precise identification of the radar trace.

Wyssen avalanche trigger

Avalanche towers

Wyssen tower

Wyssen avalanche towers in situ on the slopes of the Matterhorn, Zermatt, Switzerland.

Wyssen’s Avalanche Towers are the company’s defining product. Pioneered in the popular Zermatt ski area, the remotely controlled towers lead the field in avalanche control. The LS12-5 G3-3 models are 8m high structures, permanently fitted to the hillside in remote locations. The top of the tower is designed to hold the deployment box. Fitted to the outside are the antenna, a flashing light and the solar panels which power the electronics. A 12 V battery, the electronics, the dropping mechanism and the charges are sheltered from the elements inside the box.

Wyssen helicopter and deployment box

Helicopter lifts 600kg deployment box onto a tower (left). A loaded deployment box awaits transport.

The 600kg box is lifted into position at the start of the season by helicopter, the guidance system used means that only the pilot is required to deliver the box without needing assistance.

Wyssen kitOnce slotted onto the tower, the box orientates itself and when correctly in situ, automatically becomes operational. A GPS receiver confirms to the operating system that the right box is situated on the correct tower.

The deployment box holds 12 explosive charges, loaded on the ground at a base station before transport to the tower. Wyssen routinely use 5kg charges which, when needed, are triggered a little above the snow surface to cause maximum effect

A smaller more economical tower, the LS6-5, is available for use in more accessible zones. These are serviced manually by ladder and hold 6 charges each. They are independently powered via solar panels.


Managing technology through a single interface

Wyssen WAC.3 interface

The WAC.3 interface viewable on a variety of devices.

Wyssen’s WAC.3 software system brings all the technology together in one comprehensive interface. Information gathered in the field feeds back to the control centre and can be viewed, analysed and acted upon thanks to this two-way operative system. Site status information can be viewed at any time, both on desktop computers and mobile devices connected to the Internet.

Information is grouped into different avalanche zones which can then be managed individually or as part of a wider area. All data is available for pooling and consideration, feedback from weather stations, results from radar installations, views from the cameras and sensor etc. Should action be required, an explosive charge can be detonated once the area is considered secure. Either a single or a number of towers can be triggered, making it quick and easy to respond to imminent danger over wide areas. Records and data are archived permitting repeated reference to past cases for analysis.

Critical System relies on PodsystemM2M’s SIM card

The reliability of the solution Wyssen Avalanche Solutions offer is bolstered by the combination of their sophisticated sensor devices and management interface with a M2M data SIM card providing reliable connectivity for their devices. Looking for the perfect complement to their system, Wyssen chose to deploy Podsystem’s M2M data SIM cards in their devices. The main difference between Podsystem and other MVNOs or Mobile Virtual Network Operators is that Podsystem manufacture their own SIM cards and negotiate with operators all over the world to be able to include their IMSI (International Mobile Subscriber Identity), or network profile, on the card. This means that the end user has absolute control over the card and its connectivity. This solution, which allows global access to multiple networks on one flat rate, gives guaranteed coverage for their devices wherever they may be situated. “With the Podsystem M2M SIM cards we are able to connect our machines for controlled release of avalanches to our web-application,” explains Bejamin Meier, engineer at Wyssen. “This gives the user a very flexible interface which can be accessed from any device wherever it may be located.”

Uninterrupted transfer of data from the sensors to the central processing point is vital to ensure the continuity of monitoring and data analysis. In a situation where lives and infrastructure are dependent on the vigilance of the surveillance system, it is critical to have reliable network coverage.

By nature, the avalanche towers are situated in remote locations that are difficult to access. They must function independently, in all weathers and at all times. The M2M Data SIM developed by PodsystemM2M comes with an integral application which allows the SIM card to change from one IMSI to another automatically should the card lose its signal due to a technical difficulty on one of the networks, thus avoiding any failure in the connectivity of the devices and ensuring maximum coverage and constant data flow that can be processed by the WAC.3 system.

Reliable M2M connectivity is vital to success

In addition to providing access to over 571 networks in over 230 countries worldwide on one SIM card Podsystem can use an OTA (Over the Air) platform to send instructions to to the SIM card remotely. Being able to modify connectivity settings without having to recall devices is of vital importance when the system is remotely monitoring a situation in constant flux.

“The flexibility of the Podsystem M2M SIM card was paramount. We wanted a single SIM card, interchangeable for each device that makes up our system”, says Benjamin, “This way, management of the SIMs becomes simple and straightforward.”

With Wyssen’s sophisticated systems installed and continually interpreting the aggregated data, avalanche control officers can move their strategic planning to the next level. Obvious advantages include the ability to sustain and extend the service, predict and manage avalanche behaviour during emergency conditions.

Multinational success based on sound principles

Wyssen Avalanche Control is the market leader in Switzerland, Austria and Norway in the sector of preventive release of avalanches and has also installed systems in Canada. By the end of 2016 a total of 350 avalanche towers had been installed in Europe safeguarding communities and transport routes.

“Wyssen is proud to be head sponsor of Linard Kindschi, Swiss cross country skier. Like a top athlete we follow the basic values of dedication, progression through challenges and focus on performance, which leads us to innovation and distinction”, comments founder Sam Wyssen, “quality and durability have been standards Wyssen have adhered to since their foundation nearly one hundred years ago.”

As they place such value on customer service and reliability, it was important to Wyssen Avalanche Control to work with a company of similar gold standards. Podsystem see customer relations as a long term commitment, time is taken to understand the specific needs of each one, cooperating to find the best way to achieve an unparalleled solution. Technical back-up is provided indefinitely, so being in a time critical industry themselves, Wyssen recognised the importance of the round the clock support that Podsystem offers. “We love Podsystem’s flexibility and the personality of their customer service”, adds Benjamin, “it was an important factor in our choice of provider.”

Safety through technology

Sam Wyssen is justifiably proud of his company’s achievements, “The operating software WAC.3 for Avalanche Towers and the variety of avalanche detection systems are regarded today as state-of-the-art. Wyssen Avalanche Control is a trail blazer in this field and offers optimal solutions from the planning phase through to delivery and up to operating the installations. All of this is with the proverbial Swiss quality with regard to efficacy, reliability and support” he comments.

With the lives and economic viability of numerous mountain communities in their hands, Wyssen cannot afford to take chances, in PodsystemM2M they have found a partner able to provide a connectivity solution which enables them to deliver their services, round the clock, regardless of terrain and weather conditions to the highest standards their customers expect.