Tunnels have revolutionized transportation and infrastructure by allowing people to travel through mountains, rivers and even oceans. This blog post will explore the 10 largest tunnels built in the world.
The longest road tunnel is located in Norway between Laerdal and Aurland. It is a single two-lane tunnel that can handle ten thousand vehicles at a time.
1. Gotthard Base Tunnel
At 57 kilometer in length, the Gotthard Base Tunnel is the world’s longest railway tunnel. It connects Erstfeld to the north and Bodio in the south, allowing trains to bypass the Alps and travel as easily between northern and southern Europe. The project took 17 years to complete. The tunnel is divided into five sections. The rock condition and boundary conditions of the first four sections were suited to use of tunnel boring machines (TBMs). Four Herrenknecht Gripper TBMs were used, which were named Sissi, Heidi, Gabi I and Gabi II.
The last section posed the most difficult challenge. It runs through the Piora Basin, a funnel-shaped zone of sugargrained dolomite with loose granules that reaches deep into the Saint-Gotthard Massif. This area required extremely special technical skills for its exploration and drilling. The last section of the tunnel was opened in June 2016. Its impact is enormous, as it enables trains to cross the Alps without climbing, and thus opens up a new north-south axis for European transport.
2. Yamate Tunnel
Tunnels have played a major role in transportation infrastructure for centuries. They allow people and goods to travel over mountains, under rivers, and across oceans.
The Yamate Tunnel carries the Central Ring Road (C2) of Shoto Road in Tokyo, Japan. Its length makes it the world's second longest road tunnel.
It features fire-safety systems with emergency telephones at 100-meter intervals, ducts that supply fresh air and remove exhaust, and dust-collection systems. Tunnel traffic is monitored by cameras and manned booths.
The Channel Tunnel links Folkestone in the United Kingdom and Coquelles in northern France, carrying Eurostar passenger trains and the Eurotunnel car train. It is the third largest rail tunnel in the world.
3. Zhongnanshan Tunnel
At a length of more than 18.2 kilometers, the Zhongnanshan Tunnel is the world’s longest two-tube road tunnel. Built to allow four lanes of traffic, the $410 million project took years to complete as individual segments were designed, constructed and opened over several years. To reduce driver fatigue, the tunnel features patterned and coloured lighting and artificial plants to create a more pleasant driving experience.
The tunnel has been hailed as an engineering achievement and is a symbol of China’s ambition to conquer geographical obstacles. Its completion also contributed to the development of tunnel engineering theory, setting a precedent for long-diameter, high-altitude and buried tunnel construction. The improved accessibility has helped boost tourism in the area and has bolstered local economies. The Aurland-Laerdal single-tube tunnel between Oslo and Bergen in Norway is another example of a large mountain highway tunnel that has set new records in terms of length, altitude, buried depth and design technology.
4. Jinpingshan Tunnel
The Zhongnanshan Tunnel is China’s longest road tunnel. Opened in 2007, this amazing feat of engineering connects Shijiazhuang and Taiyuan, reducing travel time between the cities by over an hour. This is one of the most notable examples of China’s efficiency in executing complex infrastructural projects.
Laerdal tunnel is another exceptional achievement by Norwegian engineers. Instead of refurbishing the old roads, it was decided to build a tunnel that would create an essential pathway connecting two large cities. The investment paid off as the tunnel has been highly efficient with its traffic management and maintenance.
The engineers even went so far as to place beautiful images of clouds, flowers, and trees inside the tunnel to keep drivers entertained during their journey. They also took great care with the lighting so that driving through it feels like daylight.
5. Seikan Tunnel
The Seikan Tunnel, which is Japan’s longest tunnel with an undersea segment, links the country’s main island of Honshu and Hokkaido. The survey and excavation of the tunnel began in 1946 and 1964, respectively. The tunnel was finished in 1988.
The main part of the tunnel is a railway track, which connects Aomori in Honshu and Hakodate on Hokkaido. It features triple slab track type rail capable of running Shinkansen bullet trains.
During the construction of the tunnel, the workers had to use new techniques, such as laser measurement and 2150m horizontal drilling. It was the longest tunnel in the world. But, the cost of air travel between Honshu and Hokkaido quickly overtook rail and ferry travel, so the tunnel has only limited use today. Still, it remains one of the greatest engineering feats of the 20th century.
6. Tsugaru Strait Tunnel
The longest railroad tunnel in the world, the Seikan Tunnel (Japanese:
The project was initially conceived in the Taisho period, but serious surveying only began after the sinking of five ferry boats in the Tsugaru Strait in 1954 during a typhoon, killing 1,430 people. A bridge was considered too risky, so a tunnel was built. Engineers used traditional mountain tunnelling methods to excavate the tunnel, including using dynamite and mechanical picking.
7. Channel Tunnel
The Channel Tunnel, dubbed one of the Seven Wonders of the Modern World by the American Society of Civil Engineers, is an engineering marvel that makes a trip from London to Paris a snap. The tunnel is home to passenger and freight trains, as well as Eurostar roll-on/roll-off shuttle trains that can carry vehicles.
A tunnel under the English Channel had been proposed as early as 1802 by French engineer Albert Mathieu-Favier. Over the following two centuries, several surveys and plans were made, but they never got off the ground. Wartime security concerns and expense were major obstacles.
Work finally started on a tunnel between the United Kingdom and France in 1987-88. It was financed by private investors and a consortium of banks. A smaller service tunnel connects the running tunnels. Britishman Graham Fagg and Frenchman Philipppe Cozette were selected by lottery to be the first workers to break through into the other side.
8. Eisenhower Road Tunnel
The Eisenhower Road Tunnel is a vital route between the Denver metro area and world class mountain towns throughout the Rocky Mountains. It has made travel much safer and easier. Peak 1 Express is proud to use this tunnel on our transportation between the airport and the mountain town of Summit County and Vail Valley. The east- and westbound tunnels were originally named the Straight Creek Tunnel, but were renamed for Dwight D. Eisenhower and Edwin C. Johnson, who both played important roles in the development of Colorado’s interstate system.
Building these tunnels was no easy task. In fact, seven workers died during construction and many more suffered severe injuries. When the tunnels opened in 1973, they were the highest vehicular tunnels in the world. The tunnels are sloped with a 1.64% grade and reach an elevation of 11,158 feet at their eastern and western portals.
9. Guoliang Tunnel
Before the construction of this impressive tunnel, the only way to enter Guoliang village was by a path carved into the cliff side. In 1972, 13 villagers decided to construct the tunnel and dug it by hand. Three died during the process, but the tunnel transformed the village and now attracts tourists.
It's not for the faint of heart. It twists and turns with no warning, and drivers must drive at high speeds. The road is surrounded by walls that seem to fall straight down, and it features 15 separate openings that reveal a potential drop of hundreds of feet.
It's difficult to imagine how this terrifying tunnel was constructed without modern technology, but the villagers used sheep and Chinese yams they raised to buy steel hammers and chisels. It took years to complete and was opened to traffic on May 1, 1977.
10. Huangpu River Tunnel
Almost all major cities have numerous shield-bored tunnels that cross rivers, lakes, and seas for subways, railways, highways, water delivery, oil/gas supply, power supply, and so forth. The Huangpu River Tunnel is a pedestrian tunnel that runs underwater connecting the Bund in Shanghai's downtown with the Lujiazui Area of Pudong District. Its total length is 646.7 meters.
This tunnel is a challenging project because of its location in an active seismic zone with eight degrees of seismic intensity. It features hard heterogeneous ground including marine mud soil and granite with a strength of up to 216 MPa. To deal with these challenges, innovative seismic-reducing and seismic-isolating measures were used (Fig. 2).
This tunnel is designed with two tubes for traffic, and passengers ride in sightseeing maglev trains equipped with special multimedia effects. It is a unique experience that allows visitors to enjoy the beautiful sites of Shanghai.
