Tunnel construction Canton starts construction work on A8 tunnel in Kaiserstuhl OW

On Monday, the canton of Obwalden began underground work on the 2.1-kilometre-long A8 tunnel from Lungern North to Giswil South in Kaiserstuhl. The aim of the tunnel is to create a connection between the two municipalities that is safe from natural hazards.

The topping-out ceremony on Monday was accompanied by the blessing of St. Barbara, according to a statement from the cantonal civil engineering office. The pointing ceremony marks the start of the excavation work for the tunnel.

The excavation work is expected to take 2.5 years, the statement added. Due to the gradient of 6.5 percent and relatively tight radii, the miners will have to blast the tunnel out of the mountain. The tunnel is too steep for a tunnel boring machine, as the canton writes on its project website.

According to cantonal councillor Josef Hess, the excavation of the exploratory tunnel has already provided important insights into the geological conditions, as he was quoted as saying. This knowledge was incorporated into the tender for the work.

The preparatory work for the tunnel began in 2019 and the excavation of the exploratory tunnel in 2021. Hess was able to detonate the final blast in July 2022.

The major A8 project will cost CHF 268 million. 97 percent of the costs are being financed by the federal government and 3 percent by the canton of Obwalden. The road section is expected to be opened in 2029. The completion work will last until 2032.