The world's longest high-speed underwater railway tunnel, part of China's Yong-Zhou Railway, will reduce a two-hour bus journey between Ningbo and Zhoushan to just 26 minutes when the line opens in 2028. The project, backed by an investment of 27bn yuan (approximately £3.2bn), includes a 10-mile undersea section that will set a global record for submerged rail tunnels.
Project background and scope
The scheme was first proposed in 2005, but it was not until 2018 that Beijing approved the project, with construction starting in November 2022. The 47.8-mile railway will connect Ningbo, a city south of Shanghai, to the Zhoushan islands, an archipelago off China's eastern coast. A key goal is to establish a two-hour travel zone across Zhejiang Province.
The line, linking Ningbo East Station and Zhoushan (Baiquan) Station, will carry high-speed trains capable of reaching 250 kilometres per hour. Seven stations will form part of the route, with four newly built and three refurbished, while a bridge will also be constructed to connect sections of the archipelago.
Travel time savings and engineering details
Once operational, the route will cut the journey between Ningbo and Zhoushan to 26 minutes, compared with two hours by bus and up to 90 minutes by car. The new submerged route will also transport passengers from Hangzhou, Zhejiang's capital, to Zhoushan in 77 minutes, a trip that currently takes four-and-a-half hours by bus or two-and-a-half hours by car.
Dong Bing, chief mechanical engineer of the Yongzhou Railway project, said the tunnel-boring machine, named Yongzhou, is currently working about 93 metres beneath the seabed. The 135-metre-long machine helps drill through mountainous and subterranean landscapes, and those behind it claim it is "more sensitive than humans" at detecting problems during excavation.
Safety features and completion timeline
Mr Bing said: "Some problems are impossible to detect through human inspection. You might walk by and everything seems fine, but a second later, a problem arises. The system can also collect data, identify related conditions, and analyze potential causes. This is a huge help for safety."
Hao Weiqi, deputy director of the High-End Equipment Industry Technology Research Institute at China Railway Construction Corp, told Global Times: "We can tailor the machines to specific underground environments, while simultaneously providing integrated solutions that combine equipment, intelligent systems, and technical services throughout the entire construction process."
After the tunnel boring machine completes 83% of the excavation, it will link up with a second machine called Dinghai, bringing the tunnel, situated 93 metres beneath the Ningbo seabed, close to completion. The project is anticipated to be finished in 2028.
