Longest Tunnel in the World
In brief, tunnel is a man-made enclosed passageway with one entrance and exit at each end. Tunnels function not only for pedestrian, cyclists and motor-transport traffic, they are also built for water transfers, railroad etc. Of course, in common with other engineering constructions, making the tunnels in some places have become a significant challenge as well and in this article a brief insight into the longest tunnels of each category is given.
5 Longest Tunnels in the World
The world’s longest road tunnel is situated in Sogn og Fjordane in Norway and it is Lærdal Tunnel. This tunnel is 24.5 kilometers long and it connects Lærdal and Aurland. The construction work of this engineering attainment begun in 1995 and the tunnel was open to vehicles in 2000. The drive trough this tunnel takes about 20 minutes and, since it is a rather long time to be spent in one tunnel, a special design was created, so the drive would be more pleasant.
Another engineering achievement was made in 2011 when the finish of the construction of the longest rail tunnel was celebrated. This title belongs to 57 kilometers long Gotthard Base Tunnel in Switzerland. The project cost 12 billion dollars and it took more than 12 years to construct this impressive tunnel. The planning of Gotthard Base Tunnel is rather complicated but different solutions were found in order to make this tunnel more efficient and safe. The tunnel is accompanied by another parallel tunnel – Ceneri Base Tunnel, which is also imposing but does not reach the impressive length of Gotthard Base Tunnel. However, the tunnels do not host any traffic yet. Gotthard Base Tunnel is planned to be open in 2017 but Ceneri Base Tunnel – in 2019.
As it was already mentioned, tunnels are not used only for the traffic and another their function is water supply. So far the longest water supply tunnel is situated in New York and it is Delaware Aqueduct, which reaches the length of 137 kilometers. The construction work of the tunnel was started in 1939 and already in 1945 it was finished. The tunnel still is the main water supply tunnel of the city since it carries almost half of its water supply.
Metro has become integral part of majority of the people who need to get from point A to B as fast as possible. The longest metro tunnel is located in China and it is Line 3 of Guangzhou Metro. The line is more than 67 kilometers long and it includes 28 stations connecting Tianhe Couch Terminal to Panyu Square.
Procuring hydro-electric power has become rather important especially lately when alternative energy resources play a major role in preserving the environment. In many cases large diameter tunnels are made as an integral part of the power plant. The longest of these tunnels so far is the tunnel of Manapouri Hydroelectric Power Station in South Island of New Zealand. The tunnel is about 10 kilometers long and it was fully completed in 2002.
The tunnels are solving lots of problems modern world is facing. However there always will be new challenges and new records to break when it comes to building longer and longer tunnels.