|The Gotthard Base Tunnel is a railway tunnel under construction in Switzerland. With a planned length of 57 km, it will be the longest railway tunnel in the world upon completion, ahead of the current longest, the Seikan Tunnel. The project is designed to feature two separate tunnels containing one track each. There is also a proposal to build a station in mid-tunnel, Porta Alpina, near Sedrun, which will connect to the Rhaetian Railway/Matterhorn-Gotthard-Bahn east-west rail route via local buses to Sedrun and Disentis stations; access to Porta Alpina would be via an already existing access tunnel which is 1 kilometre long and elevator shafts 800 metres deep.|
The two portals will be near the villages of Erstfeld, Canton Uri and Biasca, Canton Ticino.
Completion is projected for 2015. The tunnel is part of the Swiss AlpTransit project, which also includes the Lötschberg base tunnel between the cantons of Berne and Valais. Like the Lötschberg tunnel, it is intended to bypass winding mountain routes and establish a direct route suitable for high speed rail. On completion it is expected to decrease the current 3.5 hours travel time from Zürich to Milan by one hour.
Nearby are two more St. Gotthard Tunnels: the 1882 railway tunnel and the 1980 road tunnel.