Gotthard Base Tunnel

The Gotthard Base Tunnel is a railway tunnel through the Alps in Switzerland. It opened on 1 June 2016, and full service began on 11 December 2016. With a route length of 57.09 km , it is the world's longest railway and deepest traffic tunnel and the first flat, low-level route through the Alps. It lies at the heart of the Gotthard axis and constitutes the third tunnel connecting the cantons of Uri and Ticino, after the Gotthard Tunnel and the Gotthard Road Tunnel.

The link consists of two single-track tunnels connecting Erstfeld with Bodio and passing below Sedrun . It is part of the New Railway Link through the Alps project, which also includes the Ceneri Base Tunnel further south and the Lötschberg Base Tunnel on the other main north-south axis. It is referred to as a "base tunnel" since it bypasses most of the existing Gotthard railway line, a winding mountain route opened in 1882 across the Saint-Gotthard Massif, which was operating at its capacity before the opening of the GBT. The new base tunnel establishes a direct route usable by high-speed rail and heavy freight trains.

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