Opening of the Stoosbahn funicular railway in Switzerland set a new world record for steepness but also gave passengers the first glimpse of “vertical” tunnels bored to create the route.
The 1,760m long railway track has an elevation gain of 745m and features tunnels with a 110% gradient to transport passengers into Stoos for winter and summer sports.
The railway was built by Implenia and Stossbahnen with input from Vetsch Kloster.
Work started on the scheme in 2013 and has taken four years to deliver due to disputes between the contractors and client Standseilbahn Schwyz-Stoos.
The core of the project – and the biggest challenge, according to Implenia – was the construction of three tunnels and track with gradients of up to 110%.
All three tunnels were created from top to bottom with the drill and blast method using a drilling device developed especially for the project. The “raise-drill” technique was used for the two lower tunnels, with a hole drilled through the entire length of the tunnel profile prior to blasting.
Implenia has said that the steep terrain presented a huge challenge in terms of health and safety, as well as being a challenging engineering project.
The carriages are barrel-shaped and rotate to maintain a level floor surface for passengers.