Simplon Tunnel

The Simplon Tunnel (Simplontunnel, Traforo del Sempione or Galleria del Sempione) is a railway tunnel on the Simplon railway that connects Brig, Switzerland and Domodossola, Italy, through the Alps, providing a shortcut under the Simplon Pass route. It is straight except for short curves at either end. It consists of two single-track tunnels built nearly 15 years apart. The first tunnel is 19,803 m (64,970 ft) long; the last tunnel is 19,824 m (65,039 ft) long, making it the longest railway tunnel in the world for most of the twentieth century, from 1906 until 1982, when the Daishimizu Tunnel opened. Peaking at a height of only 705 m (2,313 ft) above sea level, the Simplon Tunnel was also the lowest direct Alpine crossing for 110 years, until the opening of the Gotthard Base Tunnel in 2016. The tunnel has a maximum rock overlay of approximately 2,150 m (7,050 ft), also a world record at the time. Temperatures up to 56 °C (133 °F) have been measured inside the tunnel. Work on the first tube of the Simplon Tunnel commenced in 1898. The Italian king Victor Emmanuel III of Italy and the president of the Swiss Confederation (presiding the Federal Council of Switzerland for that year) Ludwig Forrer opened the tunnel at Brig on 19 May 1906. The builders of the tunnel were Hermann Häustler and Hugo von Kager. Work on the second tube of the tunnel started in 1912 and was opened in 1921.