If you’re looking for the Longest Underwater Tunnel in The World, then you are at the right place. In this article, we will discuss the Top 10 Longest Underwater Tunnels in The World 2023.
Humans have long known the use of natural caves as dwellings. With the development of the times, in this era of economic take-off, roads have become an important resource for development in all directions. Tunnel construction is of great value in promoting national economic growth, and improving our quality of life, and safety. Tunnel is a means of transportation that expands the space for urban development and promotes economic development. It does not hinder the navigation of ships on the water and is not affected by weather conditions such as strong winds and fog. So do you know what are the top 10 underwater tunnels in the world? let’s take a look!
Top 10 Longest Underwater Tunnels in The World
10. Shiziyang Tunnel (4.75 Km)
China’s Guangzhou-Shenzhen-Hong Kong High-Speed Rail Shiziyang Tunnel is a key project for the Guangzhou-Shenzhen-Hong Kong High-speed Railway to cross the Shiziyang Sea area. It is also the first underwater railway tunnel in China and is known as the “China Century Railway Tunnel”. The tunnel is located in Shiziyang, Pearl River Estuary, Guangdong, connecting Guangzhou Dongyong Station in the west and Dongguan Humen Station in the east.
The target speed of the tunnel is 350km/h. The total length is 10.8 kilometers and the underwater length is 4.75 km long. It is the underwater railway tunnel with the highest driving speed in the world. It is the longest underwater shield tunnel after the English Channel Tunnel. Many worldwide technical problems of this tunnel have been solved, filling in many technical gaps in the construction of mud-water pressurized balance shield machines in China.
9. Dalian Bay Undersea Tunnel (5.1 Km)
China’s Dalian Bay Undersea Tunnel is also one of the largest subsea tunnels in the world. The tunnel is designed as an 80km/h urban expressway. The span of the driving hole is 17.55 meters, which is the largest single-hole span and the largest structure outsourcing immersed tube tunnel in the world. It is also second only to the immersed tube tunnel of the Hong Kong-Zhuhai-Macao Bridge Project.
The total length of the tunnel and the Guangming Road extension project is 12.1 kilometers, two-way six-lane, the design standard is an urban expressway, and the main line of the Undersea tunnel is 5.1 kilometers long.
8. Eiksund Tunnel (5.5 Km)
The Eiksund Tunnel is located in Norway. This tunnel connects the municipalities of Ulstein and Ørsta. Ørsta is located in Møre og Romsdal County in Norway. The tunnel is located under the Vartdalsjorden fjord. It is worth mentioning that the Exon Tunnel is not only the deepest submarine tunnel in Norway but also the deepest submarine tunnel in the world.
It is 287 meters below sea level, a total of 7.7 km long and 5.5 km long underwater, and 10 meters wide. About 1,000 cars passed through the tunnel every day before the tunnel was built. After the opening of the tunnel, the number of vehicles passing through the tunnel nearly doubled.
7. Yerba Buena Tunnel (5.8 Km)
The Yerba Buena Tunnel, located in the San Francisco Bay Area of California, USA, is also one of the longest underwater tunnels in the world. Yebabuna Island is a small island in the San Francisco Bay, between Oakland and San Francisco. A Bay Bridge spans San Francisco Bay and passes through Yeba Buna Island in the form of a tunnel in the middle, which is the Yeba Buna Island Tunnel.
The tunnel is the world’s first submerged immersed tube tunnel and one of the longest submerged immersed tube tunnels in the world. Its Undersea section is 5.8 kilometers long and has a diameter of 76 feet (about 23.2 meters), making it the widest artificial single-hole tunnel in the world. The tunnel opened in November 1936. Compared to its construction history, such a wide single-bore tunnel can be regarded as a masterpiece of tunnel engineering.
6. Hong Kong-Zhuhai-Macao Bridge Undersea Tunnel (6.7 Km)
China’s Hong Kong-Zhuhai-Macao Bridge Submarine Tunnel is a world-famous subsea tunnel, and it is also the immersed tube tunnel with the largest buried depth and the most difficult comprehensive technology in the world today. The Hong Kong-Zhuhai-Macao project integrates bridges, islands, and tunnels. The main project consists of a submarine-immersed tube tunnel and a bridge project.
Two artificial islands, east, and west, are built at both ends of the tunnel. The Undersea tunnel of the Hong Kong-Zhuhai-Macao Bridge has a total length of 6.7 kilometers. After opening to traffic, the land journey from Hong Kong to Zhuhai and Macau has been shortened from 3.5 hours to 0.5 hours.
5. Boryeong Undersea Tunnel (6.9 Km)
Boryeong Subsea Tunnel is the longest subsea tunnel in South Korea, costing 485.3 billion won (about 2.6 billion yuan), 55 meters from the seabed and 80 meters from the sea level, two-way four-lane, with a total length of 6.927 kilometers, surpassing Incheon Beigang Subsea Tunnel (5.46 kilometers), set a record for the longest subsea tunnel in South Korea and the fifth longest subsea tunnel in the world.
After the opening of the tunnel, the journey from Daecheon Port in Boryeong City to Taean County will be shortened by 80 minutes, from the original one and a half hours to less than 20 minutes.
4. Tokyo Bay Tunnel (9.6 Km)
The Tokyo Bay Water Tunnel in Japan is also one of the top 10 underwater tunnels in the world. It has a total length of 15.1 kilometers and consists of three sections: the Kawasaki side submarine shield tunnel with more ships, the Kisarazu side sea bridge with shallow water depth, and the Kawasaki side. The approach part of the floating island is on the side bank.
In order to shorten the excavation distance of the shield machine, a Kawasaki artificial island was built in the middle of the sea part of the 9.9-kilometer tunnel section. The road tunnel was opened in 1997, which greatly relieved the increasing traffic pressure on the Tokyo Circle year by year. People in Kisarazu can save about 45 minutes per trip.
3. Ryfylke Tunnel (14.4 Km)
The Ryfylke Tunnel in Norway is also one of the longest underwater tunnels in the world and the longest road undersea tunnel in the world. The deepest part of the Ryfylke Tunnel is 290 meters below sea level. The tunnel section is a horseshoe-shaped section of 4.6m x 8.5m, and the section has been widened in some areas to add emergency lanes and workspace for tunnel maintenance. The tunnel construction started in August 2014. The tunnel length is 14.4 km long.
The drill and blast method was used to excavate the tunnel, and the continuous conveyor was used to discharge the slag from the long-distance drill and blast method pilot pit, and the slag was transported at a speed of 300t/h through the crusher. While excavating the working face of the tunnel with a cross-sectional area of 62m2, the connecting passages with a length of 12m to 30m and an interval of 250m are also excavated at the same time, and the shotcrete lining and electromechanical installation work are carried out simultaneously.
2. Seikan Tunnel (23.3 Km)
If you do not rank by the length of the undersea section, but by the total length, the Seikan Submarine Tunnel in Japan ranks first in the length of the longest tunnel in the world. The tunnel is named after connecting the Aomori area of Honshu, Japan, and the Hakodate area of Hokkaido. The total length is 53.85 kilometers, and the undersea part is 23.3 kilometers.
The tunnel started in 1964 and was completed in 1987. It used 168,000 tons of steel and 1.74 million cubic meters of concrete. And 2860 tons of explosives, it took 23 years to build, and it took 42 years from planning to completion, and the tunnel passed through the Tsugaru Strait between Honshu Island and Hokkaido, Japan, with a depth of 240 meters, Guinness World Records Recorded as the lowest railway line in the world.
1. Channel Tunnel (37.9 Km)
The longest underwater tunnel in the world is the Channel Tunnel, also known as the Anglo-French undersea Tunnel and the Eurotunnel. With a length of 37.9 kilometers, it is the longest underwater tunnel in the world. From February 12, 1986, when France and Britain signed the Canterbury Treaty on tunnel connection to May 7, 1994, it was officially opened to traffic.
It took more than 8 years and cost about 10 billion pounds. It is also the largest private tunnel in the world. Engineering projects for capital construction. According to estimates by the British railway authority, the number of passengers passing through the tunnel can reach 18 million and freight can reach 8 million tons every year.