Stoosbahn Switzerland - The steepest cogwheel railway in the world 

Since decades Switzerland occupies a very significant position among the top ranking, well known tunnelling nations. Today everyone thinks of the two most impressive infrastructure projects to cross the Swiss alps - the Lötschberg Base tunnel (operational since 2007) and the famous Gotthard Base tunnel, opened on 1st of june 2016, being the longest railway tunnel in the world, with a total length of 57 km. In previous centuries outstanding construction works have been commissioned by the pioneers of the tourism industry as for example, the Jungfraubahn in the Berner Oberland and the cog railway to the pilatus at Lucerne (steepest cogwheel railway in the world). To this list of famous tourist-based projects is actually added another one: the new “Stoosbahn”, the steepest funicular (cable car) in the world! Although smaller in dimension, the tunnelling expertise necessary and the required technical and logistical know-how for this particular project had to be of an unprecedented high level. the essay “The Stoosbahn - la funicolare più ripida del mondo” addresses these topics. The concession of the existing “funiculare stoos”, which was built in 1933 in Canton Schwyz, expires and cannot be prolonged. therefore a new funicular cable car had to be constructed. This new cable car, with a slope of up to 110%, is the steepest funicular in the world, with horizontal entrances to the stations (comfortable and handicap-approved accesses for passengers). the commitment to engage the most modern and innovative technology available, allows a capacity of 1500 persons per hour. Thanks to automatic levelling of the standing platform, the passengers in the 4 compartments travel in comfort on a permanently horizontal platform throughout the transfer. With a total length of 1740 m, the new stoosbahn covers a height difference of 744 m. The execution of the construction work was assigned to the JV IMPLENIA in September 2012 and is to date still ongoing. From the overall length of 1740 m a total of 230 m run on viaducts, whereas 580 m are running at ground level, with the remaining part running in 3 tunnel sections: – tunnel 1: Zingelifluhtunnel: length 260 m, slope 110% – tunnel 2: Oberzingeli: length 95 m, slope 110% – tunnel 3: Stoosfluhtunnel: length 235 m, gradient 65-23% The foregoing tunneling works are of small dimensions, but highly complex. the controlled target pilot boring at the 110% pitch was finally, after several incidents, successfully completed. here the limit of what is technically possible has been reached! Technically a fine success, the same cannot be said from a commercial point of view.