On the roof of Europe...

A nickel-containing stainless steel refuge

August 15, 2015

refuge

Hosting 25,000 to 30,000 mountaineers each year, the new Refuge du Goûter, is at an elevation of 3,835 metres and located on the main route to Mont Blanc in the French Alps. Perched on a rocky cliff edge, it was designed to withstand temperatures ranging from -50°C to +30°C and winds that can reach 300 kph.

The refuge’s ovoid form is built perpendicular to the cliff for the least possible wind resistance. The wind currents meet at the rear of the building, depositing the snow they carry. A huge drift provides a permanent and renewable reserve of fresh water for the refuge. Heat collectors on the roof, solar panels on the façade, the use of biomass produced internally, and the recycling of waste water mean the new refuge is nearly 100% energy and water self-sufficient.

Strong mechanical resistance, low reflectivity

Wood was the preferred construction material because of its light weight and ease of construction at high elevations. However, because it was too fragile to withstand the extreme climatic conditions, the project architects and engineers came up with the solution of cladding the wooden structure. Nickel-containing stainless steel offered the necessary set of properties including long life and low maintenance in a cold environment—the surface would be cleaned naturally by the wind and snow. Low reflectivity from the sun was another necessary feature so that hikers and aircraft pilots would not be blinded as well as to ensure the refuge’s integration into the snowy environment.

A complex set of facets

Type 304 (EN 1.4301, UNS S30400) stainless steel containing 8.0% minimum nickel, with a Uginox “Top” finish was selected in two thicknesses: 0.5mm for the roof and 0.8 mm for the facade. This is a double-sided matte finish with a surface roughness of about 1.5µm. The structure comprises a complex puzzle of 128 facets evenly distributed over four levels (32 facets per level), in four basic dimensions: 2m x 4m (16 facets); 2m x 3m (48 facets); 1.3m x 3m (48 facets). Each facet was itself divided into four or seven bands of stainless steel measuring 2.50 and 2.80m in length. In all, nearly 800 stainless steel sheets were cut.

High-altitude assembly

All the components were prepared by subcontractors in the valley then transported by helicopter to the platform for assembly on Mont Blanc. The stainless steel bands were assembled using flat Z-joints. To ensure the full aerodynamic effect around the shell, the stainless steel cladding, windows and solar panels had to be perfectly aligned in the same plane on each of the facets.

Opened in 2013, the new Refuge du Goûter can accommodate 120 people and replaces a 1960s shelter which was no longer fit for purpose. At a cost of €6 million, it is an incredible feat of engineering and a sanctuary for climbers on their way to conquer the roof of Europe.


Current Issue

Nickel and sustainability

Towards a circular economy

August 30, 2018

NickelVol33No1Spring2018_Thumbnail

Feature Story:
A catalyst for sustainable operations
Nickel-containing catalysts are widely used in the refining and petrochemical industries worldwide. At end-of-life, catalysts are either sent to landfill or sent for recycling to recover the valuable metals they contain. Refineries in Kuwait are changing the way they handle spent catalysts.