Global economic analysts are estimated that populations within major world cities are increasing at a rate of around 40 million people every year. This means that space within which to expand the infrastructure necessary to support such populations is becoming harder to acquire and more costly. Therefore, transportation infrastructure such as rails and roads are increasingly being constructed within subterranean tunnels. Tunneling is an important technique because it allows traffic to pass through the underground realm even in places construction of buildings and other civil structures has taken place on the surface. Additionally, constructing underground is much less destructive form of human engineering activity, resulting in considerably less pollution than that seen with conventional land development.
Where are these Massive Tunnels Located?
Most of the world's longest railroad and highway tunnels are found on the European and Asian continents, where dense populations have pushed aboveground living spaces to their limits. Of the world's 10 longest rail tunnels, four are in Japan, two are in China, and three in Europe.
The World’s Longest Transportation Tunnels
The most famous underground rail and road tunnel is the Eurotunnel, more commonly referred to as the Channel Tunnel. As it runs under the English Channel to connect the UK and France, the 50.5 km tunnel is almost exclusively under the sea. Opened in 1994 at a cost of almost $15 million dollars, the system includes 4 tunnels in all, including a service tunnel and an emergency lane.
In 2010, Switzerland celebrated the completion of the longest stretch of underground rail connection. The Gotthard Base Tunnel snakes for a mind-boggling length of 57,072 meters! Some sections of the tunnel are exposed, as it has 1000 meters constructed above the surface. Up to 40% of Switzerland's cargo is handled over land, and the tunnel has helped a lot of this bypass the arduous Alpine terrain. The mountains render the construction of flat roads a difficult feat, and prompted construction of this and other large tunnels in the country.
In Japan, the Seikan Tunnel connects the islands of Hokkaido and Honshu. The ingenious engineering feat is just under 54km meters in length, and spans a maximum width of about 10 meters in places. Notably, a 23 kilometer stretch of this tunnel is at an depth of 100 meters below the seafloor of the Tsugaru Strait in the Japanese Sea. It has two major underground stations that serve the high-speed passenger trains that have run on its rail lines since the tunnel was first opened in 1988. The Seikan Tunnel is the longest continuous underground railroad in Japan, followed by the 24km Hakkoda Tunnel that was opened in 2005. Another of Asia's most notable railroad tunnels is the massive Wushaoling Tunnel in China. Being constructed in a major earthquake zone, and required extensive steel reinforcement.
Is there any Limit to How Far We Can Tunnel?
Indeed, the Chinese have always been an ambitious people. Recently, the Chinese Transport Minister was even quoted as saying that construction of a new railway beneath Mt. Everest was a distinct possibility! The rationale behind such an undertaking would be to extend China’s economic influence westward, and hasten shipments between China and India. The Chinese also have proposed another, even more stratospheric plan: construction of a railroad tunnel from China to the United States, passing under parts of Siberia and the Bering Strait. The feasibility of such an idea, however, remains to be seen.
A Crowded Middle East Sees Light at the End of the Tunnel
While the most notable transportation tunnels are in East Asia and Western Europe, other regions are fast to latch on to the idea. The rapid growth of Middle Eastern cities over the last few decades has strained the land resources in an already densely populated region. Thus, there is simply no space for construction of railways above the ground, development of railway tunnels has been increasingly postulated. In this region, similar successes, though on a much smaller scale, have been realized. For instance, the Dubai Metro is among the most technologically advanced subway systems in the world, with a network of 75km of interconnecting railroad tunnels jetting passengers to and fro beneath one of the world’s most wealthy cities.
The World's Longest Railroad And Road Tunnels
|Rank||Tunnels & Railroads||Meters|
|1||Gotthard Base Tunnel (Switzerland)||57,072|
|2||Brenner Basis (Austria)||55,392|
|3||Seikan Tunnel (Japan)||53,850|
|4||Channel Tunnel (UK-France)||50,450|
|7||New Gunjiao (China)||32,645|
|8||Guadarrama Tunnel (Spain)||28,419|
|9||West Quinling (China)||28,240|
|14||Lainzer / Wienerwald (Austria)||23,844|
|15||South Luliangshan (China)||23,464|
|16||Middle Tianshan (China)||22,452|