Building tunnels is a peak of the construction art and science. Walking or going through a tunnel is a very impressive thing for many people, nevertheless they don’t think about that at the instant.
Fact is that building tunnels is not necessary a modern knowledge. Unbelievable, but true, there are man made tunnels which are very old. Very old, but not obsolete: an Iranian aqua duct serving for water transport is 5000 years old, and still in use! You don’t need to be a construction engineer for thinking about the difficulties of building a tunnel .I think those antic constructors are really to admire.
In the good old times the tunnels had mainly defense purposes, they were secret passages. Newer, in the modern times, things changed dramatically, but a tunnel remains a masterpiece.
The Thames Tunnel is an underwater tunnel, built beneath the River Thames in London, United Kingdom, connecting Rotherhithe and Wapping. It measures 35 feet (11 m) wide by 20 feet (6 m) high and is 1,300 feet (396 m) long, running at a depth of 75 feet (23 m) below the river's surface (measured at high tide). It was the first tunnel known successfully to have been constructed underneath a navigable river, and was built between 1825 and 1843 using Thomas Cochrane and Marc Isambard Brunel's newly invented tunnelling shield technology, by him and his son Isambard Kingdom Brunel.
The Tokyo Bay Aqua Line , also known as the Trans Tokyo Bay Highway, is a bridge-tunnel combination across Tokyo Bay in Japan. It connects the city of Kawasaki in Kanagawa Prefecture with the city of Kisarazu in Chiba Prefecture, and forms part of National Route 409. With an overall length of 14 km, it includes a 4.4 km bridge and 9.6 km tunnel underneath the bay the fourth longest underwater tunnel in the world.
The interior of the tunnel is rock-faced, with concrete reinforcement at selected locations. Work on the tunnel was started in 1927 by the Nevada Construction Company and was completed in 1930 at a cost of $503,000. At the time of its completion it was the longest non-urban road tunnel in the United States. The tunnel's restricted dimensions require that vehicles over 11.33 feet (3.45 m) in height or 7.83 feet (2.39 m) in width give advance notice so that two-way traffic can be shut down in the tunnel, allowing oversize vehicles to proceed down the center of the tunnel. Vehicles over 13.08 feet (3.99 m) tall and semi-trailers as well as bicycles and pedestrians are prohibited in the tunnel.
PATH is a 28-kilometre (17 mi) network of pedestrian tunnels beneath the office towers of Downtown Toronto, Ontario, Canada. According to Guinness World Records, PATH is the largest underground shopping complex in the world with 371,600 m² (4 million sq. ft.) of retail space.
In 1900, the Eaton's department store constructed a tunnel underneath James Street, allowing shoppers to walk between the Eaton's main store at Yonge and Queen streets and the Eaton's Annex located behind the (then) City Hall. It was the first underground pedestrian pathway in Toronto, and is often credited as a historic precursor to the current PATH network.
The tunnels of Cu Chi are an immense network of connecting underground tunnels located in the Cu Chi district of Ho Chi Minh City (Saigon), Vietnam, and are part of a much larger network of tunnels that underlie much of the country. The Củ Chi tunnels were the location of several military campaigns during the Vietnam War, and were the Viet Cong's base of operations for the Tết Offensive in 1968.
The tunnels were used by Viet Cong guerrillas as hiding spots during combat, as well as serving as communication and supply routes, hospitals, food and weapon caches and living quarters for numerous guerrilla fighters. The tunnel systems were of great importance to the Viet Cong in their resistance to American forces, through which they secured American withdrawal from Vietnam and ultimate military success.
6. Gotthard Base Tunnel
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.
Its main purpose is to increase total transport capacity across the Alps, especially for freight, notably between Germany and Italy, and more particularly to shift freight volumes from road to rail to reduce environmental damage caused by ever-increasing numbers of trucks. A secondary benefit will be to cut the journey time for passenger trains from Zürich to Milan by about an hour and from Zurich to Lugano to 1 hour 40 minutes.
7. Jiucyudong Tunnel
Why It's Unique: The Tunnel of Nine Turns dices through marble cliffs and runs along a river bank in Taroko National Park, an area known for its rich geology, including a form of jade endemic to Taiwan. Completed in 1996, the structure gives tourists a unique glimpse of natural marble formations, though falling rocks do pose a real threat--and helmets may be required for sightseers.
8. Eisenhower Memorial Tunnel
The Eisenhower bore is 1.693 mi (2.72 km) long while the Johnson bore (eastbound tunnel) is 1.697 mi (2.73 km) long. The tunnels are sloped with a 1.64% grade, with an elevation of 11,013 feet (3,357 m) at the east portal and 11,158 feet (3,401 m) at the west portal. At the time of dedication, they were the highest vehicular tunnels in the world.
9. Channel Tunnel
The Channel Tunnel is a 50.5-kilometre (31.4 mi) undersea rail tunnel linking Folkestone, Kent in the United Kingdom with Coquelles, Pas-de-Calais near Calais in northern France beneath the English Channel at the Strait of Dover. The Channel Tunnel possesses the longest undersea portion of any tunnel in the world.
10. Lærdal Tunnel
Lærdal Tunnel is a 24.51-kilometre (15.23 mi) long road tunnel connecting Lærdal and Aurland in Sogn og Fjordane, Norway. It is the longest road tunnel in the world, and carries two lanes of European Route E16, the main road between Oslo and Bergen. In 1975, the Parliament of Norway decided that the main road between Oslo and Bergen would run via Filefjell, and in 1992 passed legislation to build the tunnel. Construction started in 1995, and the tunnel opened in 2000. It cost 1,082 million Norwegian krone, although unlike most tunnels in Norway was not subject to tolls.