China has achieved a major milestone in boring through the route beneath the Yangtze River, setting a record for the longest continuous underwater tunnel excavation using a 15-metre boring machine.
The Chongtai Yangtze River Tunnel project is scheduled for completion by the end of 2026. It will connect Chongming Island — China's third-largest island, located in Shanghai — with the city of Taicang in Jiangsu Province, bringing high-speed rail access to Chongming Island for the very first time.
Xinhua News Agency reported that the tunnel boring machine, named "Linghang," excavated an underwater stretch of 11.3 kilometres. The operation required millimetre-level technological precision to accommodate trains travelling at speeds of up to 350 kilometres per hour, which will make this the world's fastest underwater high-speed rail tunnel when it opens.
China Railway Tunnel Group, the state-owned enterprise responsible for the project, revealed that crossing the Yangtze River through this tunnel will take just two minutes. The tunnel sits 89 metres below the riverbed and has been engineered to withstand enormous water pressure as well as the risk of soil subsidence.
Wang Yi, Deputy Project Manager at China Railway Tunnel Group, stated that because the project is designed for speeds of 350 kilometres per hour, even the slightest deviation during boring could affect safety and passenger comfort, making millimetre-level precision of the boring machine essential. The success of the Linghang boring machine, he said, proves that China has mastered the core technology for constructing underwater high-speed rail tunnels, and it will serve as a replicable solution for other infrastructure projects in the future.
The Chongtai Tunnel project is expected to require a total investment of more than 7.1 billion yuan (approximately 35.5 billion baht). It forms a key component of the Shanghai–Chongqing–Chengdu high-speed rail line, a major corridor linking large city clusters between the coast and the country's interior. The full high-speed rail line is estimated to require a total investment of more than 530 billion yuan (approximately 2.65 trillion baht).
Once fully operational, the line will become an approximately 2,000-kilometre economic corridor connecting more than one quarter of the country's advanced manufacturing clusters and covering 40 percent of the nation's strategic state research laboratories.
Source: South China Morning Post
