The Gotthard Base Tunnel (GBT) is a new railway tunnel beneath the Swiss Alps, expected to open in 2016.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, it is the world’s longest rail tunnel, surpassing the Japanese Seikan Tunnel.
A decade ago, miners began digging outward from two 2,600-foot vertical shafts in Sedrun, Switzerland. They’ve since moved 31 million tons of rock to connect Italy to Germany via high-speed rail.
Manufacturer Herrenknecht built four 3,000-ton boring machines for the project, and after one of them encountered a zone of dangerous soft rock, crews began using a unique system of deformable steel rings to hold the tunnel open. The Gotthard will double freight capacity through one of Europe’s most vital trade corridors and will cut an hour from the four-hour trip between Zurich and Milan.