Switzerland-based HS Frech Hoch AG has announced that it has supplied 136 containers, made from Outokumpu stainless steel, for a Swiss railway tunnel to house electromechanical equipment under demanding environmental conditions. The 34.6km tunnel connecting Frutigen and Raron in Switzerland through an Alpine peak was officially opened for regular traffic in December 2007, enabling high-speed train travel through the Swiss Alps. In 2008, trains will travel at speeds up to 200km/hr through the tunnel, designed eventually to speed up to 250km/hr. This dual tube, single-track tunnel is operated with the help of 101 transverse tunnels connecting the tubes. These connections house the tunnel’s electro mechanical infrastructure, as well as serving a safety function fitted with stainless steel fire safety doors. The electro mechanical equipment is built into 136 stainless steel containers. The containers have been designed to operate under extraordinary conditions inside the tunnel at a constant temperature of approximately 30C and atmospheric humidity of up to 80%. The rock conditions place further demands on the construction materials as chloride containing water seeps through the rock with droplets falling onto the containers. Outokumpu’s R&D arm was able to provide all the required extensive paperwork, as the only stainless producer within the bidding period. Outokumpu’s stainless configuration for the containers, defined by the Group R&D specialists, was Outokumpu’s proprietary super austenitic grade 254 SMO® for the roof, and austenitic 1.4404 and 1.4301 for the outer and inner wall structures respectively. Again via Hans Kohler, Outokumpu has also supplied stainless steel for the fire safety doors of the transverse tunnels: both 1.4404 and super austenitic 904L.
