What are those big metal tubes that stick out of the ground?
What are those big metal tubes that stick out of the ground?
They set off avalanches, They water the grass in summer or They’re a shelter for hibernating marmots?
The large metal tubes that protrude from the ground, particularly under the Saulire, are called GAZEX. In winter, they're not used to keep marmots warm, but to protect the ski area against avalanche risks... And there are other avalanche protection devices - have you heard of them?
Avalanch prevention
Avalanche Trigger Response Plan
In the mountains, it’s not uncommon for heavy snowfall to occur! At times like these, up to several meters of snow can accumulate. Or, in the spring, the snowpack warms up and becomes particularly unstable. Or during periods of strong winds that cause snow to pile up in certain spots… There are plenty of situations that pose risks to skiers and infrastructure.
After assessing the risks and the data collected in the field, the ski area director decides whether or not to implement an avalanche control plan (PIDA) in the ski area and when to do so (early in the morning before opening, or during the day—often the case in the spring, to prevent the snow from refreezing and thus achieve better results). During the 2021–2022 season, this procedure was implemented about twenty times.
In Courchevel, bomb disposal experts have three types of devices at their disposal to secure the slopes:
Gazex
Catex
Manual shots
A typical PIDA proceeds as follows:
5 a.m. : First test firings conducted by GAZEX.
7:00 a.m.: Arrival of all personnel and deployment of teams to the various firing positions.
9:00 a.m.: The goal is to open the main trails first, with the others to follow.
The various avalanche-triggering devices
Gazex
These are the famous large tubes we mentioned at the beginning of the article. Here, an explosion-based gas technique (using a mixture of propane and oxygen) is used, which has the advantage of not requiring the handling of explosives.
This permanent system makes it possible to secure areas that are difficult for bomb disposal experts to access on skis. The devices are remotely controlled by the heads of the trail maintenance departments.
In Courchevel, there are no fewer than 82 Gazex lifts that can all be put into operation within an hour and a half. To spot one, take the Marmottes chairlift and look down at your feet. Can you find the others scattered throughout the ski area?
Catex
The Catex is a cable system that transports the explosive; it resembles a ski lift: the explosive is attached and then moved to a position above the avalanche starting zone. Its advantage is that you can choose where to detonate, provided you have a clear line of sight to the charge. This can be useful on days with strong winds, for example.
The Courchevel ski area has 5 Catex units. You’ll see one near the top station of the Chanrossa chairlift. We’ll let you discover where the other 4 are hidden…
Manual Triggers
Finally, there are also manual detonations, in which the tracker places the charge on the area to be secured. This is the most precise method, since it allows for precise placement of the explosive.
Ski patrol
The experts
As part of their mission to secure the ski slopes, the ski patrol team take various measures to control the risk of avalanche. Two years after qualifying, they can move on to specialise in different areas:
Snow and meteorological specialist
They take readings and make meteorological and snow observations to create a regular report on the estimation of the avalanche risk, in collaboration with Météo France. It is called the BERA (‘Bulletin d'Estimation du Risk d'Avalanche’).
Munitions specialist
They’re at the origin of those big ‘boom’ sounds heard around resort early in the morning. What are they doing? They are making our ski area safe from avalanches!
Dog handler
That ’s right, man’s best friend plays an important role in our job and is a vital resource for the ski patrol! The dog handler, accompanied by their four-legged assistant, endeavors to locate avalanche victims who have been buried under the snow, as quickly as possible. Fanny tells us more about what exactly it means to be an avalanche rescue dog handler.
As part of the Avalanche Control Response Plan (Plan d’Intervention de Déclenchement d’Avalanches or ‘PIDA’), the whole on-duty team on the day is called to action. Though only the munitions team are qualified to handle explosives, the other ski patrollers are there for support and to help with logistics and safeguard security.
Did you know? The job of ski patroller was invented in Courchevel