Work on the «Südumfahrung Visp» was started in the late 80s as part of Switzerland's national roads plan. The main arterial road, the A9, which links Geneva and Milan runs here and from Visp you can easily reach Staldbach and Saas-Fee. It was decided to build the project nto the mountains with tunnels for motorway Class A and there were numerous contracts involved over several stages, according to a master plan with a target completion date of 2016.
Südumfahrung Visp mainly consists of three projects: «Grosshüs», «Chatzuhüs» and «Tunnel Eyholz», all with different main contractors and associates. But there is one common name to be found amongst all the projects, and that's Protan Ventiflex and their ventilation pipes.The last of the main contracts for this project was «Tunnel Eyholz», which was awarded to Frutiger AG in 2007. Tunnel Eyholz is the eastern part of the overall project and consists of a northern and a southern section each 4.2 km long and an average crosssection width of around 130 m2. But in the western portal, where work was started in August, there are also access ramps which required blasting a cross-section area of right up to 320 m2! This cavern is scheduled for completion in April 2010, when work will start on both sections for the tunnel. As work will be going on around the clock, the plan is to advance 1 - 1.5 metres per day with breakthrough sometime in late 2011.
Ventiflex was awarded the contract for ventilation pipes in August this year. We ended up with a solution based on a pipe diameter of 2.5 m. The tunnel length requires a relatively high air pressure at the fans, and to achieve this, we had to offer our strongest specification, 6698FR. But as the air pressure gets less along the length of the tunnel, we proposed switching to a lower specification halfway through to the customer. Ventiflex represented the most economic alternative and for the technical terms, our products are preferred. Our first delivery was made in September, and the first ventilation pipes have already been installed. The project is on schedule despite hitting some difficult graphite zones around the western portal.