7 Longest Undersea Road Tunnels

Tunnels, like bridges, are modern engineering marvels, despite the fact that humans have been boring them for thousands of years. We used to carve tunnels out of gigantic granite walls with chisels and hammers, but our methods have improved over the decades. Tunnel Boring Machines (TBMs), sometimes known as “moles,” is now used to bore tunnels, allowing us to dig deeper and farther than ever before. We can unearth quicker and smarter with contemporary technology, resulting in huge networks of tunnels that drastically reduce travel time between destinations. Due to their hilly topographies, the longest and most magnificent tunnels are currently located in countries of Europe and Asia.

As previously said, the longest tunnels are found on continents such as Europe and Asia, but other modern marvels may be found all over the world. To offer you a complete view of the world’s longest rail and road tunnels, we have featured seven of the world’s longest undersea tunnels below.

Here are the top seven underwater tunnels in the world.

1. Thames Tunnel ( 0.4 kilometers)

The Thames Tunnel, which opened in 1843, is the world’s oldest underwater tunnel. People traveled from all over the world to see the Thames Tunnel, which was the first tunnel to be built beneath a navigable river using cutting-edge tunneling shield technology. The Thames Tunnel connects the cities of Wapping and Rotherhithe and is located beneath the Thames River in London, England. Although it was designed to accommodate horse-drawn carriages, it now serves as an important element of the London Overground railway network.

2. Vardo Tunnel (2.9 kilometers)

 Vardo Tunnel (Norwegian: Vardtunnelen) is a subsea road tunnel in the Norwegian municipality of Vardo, in the county of Troms og Finnmark. The Bussesundet strait links the island of Vardya to the village of Svartnes on the mainland’s Varanger Peninsula by a 2,890-meter (9,480-foot) two-lane tunnel. The tunnel lies 88 meters (289 feet) below sea level and is part of the European Route E75 roadway. The tunnel was Norway’s first undersea tunnel, opening in 1982. On August 16, 1983, King Olav V declared the tunnel open.

3. North Cape Tunnel (6.8 kilometers)

The North Cape Tunnel, located in the Nordkapp Municipality in Norway’s northern region, is one of the country’s longest underwater tunnels. It connects Mageroya Island to the mainland and is located beneath the Magerysundet strait. It originally opened to the public in June 1999, but passengers and freight had to be transported over the oceans from Honningsvag and Kajford before then. The European route E69 passes via the North Cape tunnel. It is also one of Lapland’s most popular tourist sites, as visitors may enjoy panoramic views from within the North Cape Hall.

4. Boryeong Tunnel (7 kilometers)

11 years of building, Boryeong, Southcheong Province, finally opened its doors, the country’s longest undersea tunnel and the fifth-longest in the world will open to traffic. According to the land ministry, the approximately 7-kilometer tunnel connecting Daecheon Port in Boryeong and Yeongmok Port in Taean will shorten the time it takes to go from one port to the other by 80 minutes. That means it will take no more than 10 minutes. Prime Minister Kim Boo-kyum hailed the launch at a ceremony, saying he hopes many tourists will visit the region next year.

5. Taihu Tunnel (10.79 kilometers)

Taihu lake tunnel project site, wuxi city, jiangsu province, China

China’s largest underwater highway tunnel has opened to traffic a little under four years after construction began. The Taihu tunnel, which runs 6.65 miles beneath Lake Taihu, provides traffic relief and a shortcut between Shanghai and Nanjing, Jiangsu Province’s capital. The six-lane tunnel is over 60 feet broad and includes more than 2 million cubic meters of concrete. According to the Xinhua news agency, the builders employed AI and automatic steel processing technology to avoid sewage and dust from being discharged during building. The tunnel is part of the Changzhou-Wuxi Highway, which runs for 27 miles and connects communities surrounding Lake Taihu, China’s third-largest freshwater lake. LED lights are installed in the tunnel’s ceiling to keep drivers awake as they travel through.

6. Seikan Tunnel (23.3 kilometers undersea segment)

The Seikan Tunnel is a 53.85-kilometer (33.46-mile) dual-gauge railway tunnel in Japan, featuring a 23.3-kilometer (14.5-mile) section beneath the seabed of the Tsugaru Strait, which connects Aomori Prefecture on Honshu’s main island and Hokkaido’s northern island. The track is roughly 100 meters (330 feet) below sea level and 240 meters (790 feet) below the seafloor. The Tsugaru-Kaiky Line of the Hokkaido Railway Company (JR Hokkaido) includes the standard gauge Hokkaido Shinkansen and the narrow gauge Kaiky Line. Seikan is derived from the on’yomi readings of the first characters of Aomori, the nearest major city on the Honshu side, and Hakodate, the nearest major city on the Hokkaido side. The Seikan Tunnel is the longest tunnel with an undersea section in the world (the Channel Tunnel, while shorter, has a longer undersea segment). It is also the second-longest main-line railway tunnel after the Gotthard Base Tunnel in Switzerland, which opened in 2016. It is also the second-deepest transport tunnel below sea level after the Ryfylke Tunnel, a road tunnel in Norway that opened in 2019.

7. Channel “Chunnel” Tunnel (37.9 kilometers underwater portion)

A Eurotunnel Shuttle full of artic lorries enters the Eurotunnel, Cheriton, Folkestone, Kent. United Kingdom. The Channel Tunnel is a 50.45-kilometre rail tunnel linking Folkestone, Kent, in the United Kingdom, with Coquelles, Pas-de-Calais, near Calais in northern France, beneath the English Channel. (photo by Andrew Aitchison / In pictures via Getty Images)

The Channel Tunnel (also known as the Chunnel, French: Tunnel sur la Manche) is a 50.46-kilometer (31.35-mile) railway tunnel that runs through the English Channel near the Strait of Dover, connecting Folkestone (Kent, England, UK) with Coquelles (Hauts-de-France, France). It is the island of Great Britain’s only fixed link to the European mainland. It is 75 meters (250 feet) below sea level and 115 meters (380 feet) below sea level at its lowest point. The tunnel features the longest underwater portion of any tunnel in the world, measuring 37.9 kilometers (23.5 miles), and is the world’s third-longest railway tunnel. Trains must go at a maximum speed of 160 km/h through the tunnel (100 mph).

Tunnels are among the most incredible feats of engineering. They are laid across mountains and even water to fulfill the demands of highways and roads, and they handle traffic efficiently.