The world’s longest and deepest tunnel opened in Switzerland on June 1, after almost two decades of construction work. The 57-kilometer-long twin-bore tunnel replaces Japan’s 53.9-km Seikan rail tunnel as the longest in the world, pushing into third place the 50.5-km Channel Tunnel, which links the U.K. and France. The project costs more than $12 billion and travels more than 2.3 km below the surface of the mountains. To create the tunnel, 28 million tonnes of rock were excavated, then crushed to make concrete for the tunnel. The tunnel’s course is flat and straight, instead of winding up through the mountains like the older rail and road tunnels. About 260 freight trains and 65 passenger trains will pass through the tunnel each day.
Under the Alps, Swiss Complete World's Longest Tunnel
June 8, 2016