Gotthard Base Tunnel – Big Bigger Biggest| National Geographic documentary HD

The Gotthard Base Tunnel (GBT) is a railway tunnel through the Alps in Switzerland expected to open on 2 June 2016.[4][5] With a route length of 57 km (35.4 mi) and a total of 151.84 km (94.3 mi) of tunnels, shafts and passages,[3] it will be the world's longest and deepest traffic tunnel[6] and the first flat low-level route through the Alps.[7] The project consists of two single-track tunnels connecting Erstfeld (Uri) with Bodio (Ticino) and passing below Sedrun (Graubünden). It is part of the AlpTransit project, also known as the New Railway Link through the Alps (NRLA), which includes the Lötschberg Base Tunnel between the cantons of Bern and Valais and the under construction Ceneri Base Tunnel (scheduled to open late 2019) to the south. It bypasses the Gotthardbahn, a winding mountain route opened in 1882 across the Saint-Gotthard Massif, which is now operating at capacity, and establishes a direct route usable by high-speed rail and heavy freight trains.[8] It is the third tunnel connecting the cantons of Uri and Ticino after the Gotthard Tunnel and the Gotthard Road Tunnel.