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Switzerland is a country best known for its peaks. The country also peaks in stainless steel consumption per capita. It is second only to Japan, and ahead of the EU average by 22 percent.
After fifteen years in the making, a 34.6-kilometer railway tunnel was opened in the Swiss Alps. The tunnel connects Frutigen and Raron in Switzerland through an Alpine peak and was officially opened for regular traffic in December 2007, enabling high-speed train travel through the mountain range.
In 2008, trains were able to travel at speeds up to 200 kilometers-per-hour through the tunnel. It has been designed to eventually allow trains to travel at speeds up to 250 kilometers-per-hour.
The concept
The dual-tube, single-track tunnel is operated with the help of 101 transverse tunnels which connect the tubes. The connections house the tunnel’s electro-mechanical infrastructure, and also serve as a safety function as they are fitted with stainless steel fire safety doors. The electro-mechanical equipment is built into 136 stainless steel containers.
The steel containers have been designed to operate under extraordinary conditions inside the tunnel: a constant temperature of approximately 35°C and atmospheric humidity of up to 80 percent.
The rock conditions place further demands on the construction materials: chloride-containing water seeps through the rock with droplets falling onto the steel containers.
The solution
The tunnel designers were looking for makers of steel containers that could guarantee a long, maintenance-free service life. They wanted a 10-year guarantee for the stainless material, and insisted the provider also fulfil a host of other conditions.
The bid for the contract was won by three companies; FHS Frech-Hoch AG, a Swiss specialist in containers for transport who relied on their long-time supplier, stainless steel distributor HANS KOHLER AG of Switzerland. And HANS KOHLER relied on their long-term supplier: Outokumpu.
Outokumpu’s stainless configuration for the steel containers was Outokumpu’s proprietary super-austenitic grade 254 SMO®for the roof and austenitic 1.4404 (ASTM 316L) and 1.4301 (304)for the outer and inner wall structures respectively.
Outokumpu also supplied stainless steel for the fire-safety doors of the transverse steel tunnels using both 1.4404 and super-austenitic 1.4539 (904L).
The results
The concept used for this project, created by Outokumpu, has cut down the electrical installation time by two years.
Martin Vögeli, Marketing and Sales Manager for HANS KOHLER, comments on the cooperation with Outokumpu: “This important project was challenging in every respect. It proved that we’re working with the right stainless producer as concerns technical service, reliability and quality.” |