The world’s longest railway tunnel, the Gotthard Base Tunnel in Switzerland, has been completed using welding solutions offered by Leister Technologies AG. The 57.04 km tunnel is also the deepest railway tunnel in the world, with a maximum depth of 2,450 metres. The tunnel construction commenced in November 1999 and was completed in 2016.
Leister Technologies AG is the leading supplier of plastic welding solutions across the globe. Around 1,000 km of high quality seam welding for the tunnel was undertaken using Leister’s TWINNY S automatic welding machines and hot air hand tools. Despite its small dimensions, a welding speed of up to 6.5 feet per minute was accomplished using TWINNY S. The compact combination wedge device of the TWINNY S enabled overhead welding by pressing the two sheets together and, thereby, rising safely and steadily during welding. To guarantee safety, a test channel was installed for each overlap weld.