The world's longest tunnels
Workers excavating the last stretch of what will be the world's longest tunnel were due to meet deep under the Swiss Alps on Friday, taking a step towards the creation of a new high-speed rail link between northern and southern Europe.
A factfile on the world's longest tunnels:
- Gothard Base Tunnel, Switzerland, 57 kilometres (35.4 miles):
Twin-bore rail tunnel, to open in 2017. Will link two Swiss villages on either side of the Gothard mountain range. Including access passageways, the structure comprises a total of 158.1 kilometres (93.2 miles) of tunnel, the last few metres of which were being completed on Friday.
- Seikan rail tunnel, Japan, 53.8 kilometres (33.4 miles):
Single-bore undersea tunnel connecting the main Japanese island of Honshu to the northern island of Hokkaido. Opened in 1988.
- Channel Tunnel, France-Britain, 49.9 kilometres (31 miles):
Twin-bore undersea rail tunnel linking the northern coast of France and the southern coast of England under the English Channel. Opened in 1994.
- Loetschberg tunnel, Switzerland, 34.6 kilometres (21.5 miles):
Twin-bore railway tunnel opened in 2007 under the Loetschberg mountain range in the Alps. Like the new Gothard Tunnel, it is part of the TransAlp plan to move traffic, particularly freight, off Switzerland's roads and onto the railways.
- Guadarrama rail tunnel, Spain, 28.4 kilometres (17.6 miles):
Twin-bore tunnel under the Guadarrama mountain range near Seville, in south-central Spain. Part of the high-speed Madrid-Valladolid rail line, it opened in 2007.
Like the above tunnels, the world's sixth-longest, the Iwate-Ichinohe in Japan (25.8 kilometres, or 16 miles), is a rail link.
The longest road tunnel in the world, and the seventh longest tunnel of any kind, is the Laerdal link in western Norway, which is 24.5 kilometres (15.2 miles) long and was completed in 2000.
© 2010 AFP