The Galgenbuck Tunnel in the canton of Schaffhausen has a total length of 1,138 metres. After around two and half years of boring, the breakthrough came in February 2016.
Once again, precision in planning and execution was paramount. The location of the main drive and the two small reverse drive mine galleries was systematically checked and the breakthrough point had to be accurate to the nearest centimetre.
Special Features of the Project
Since boring commenced in July 2013, there has been an average of between two and three blasts per day. A total of 120,000 m3 of mountain rock has been removed and around 1,700 tonnes of steel and 26,000 m3 of concrete has been installed in the tunnel. However, the breakthrough and the end of the blasting and construction work merely mark the end of yet another stage in a long process. The bore diameter of the final 125m up to the portal in Bahntal, where the reverse drive mine galleries are located was expanded to the size of the tunnel cross section.