The huge new 24-mile tunnel China's about to build under world-famous river

China is currently planning to build the world's longest underwater motorway tunnel beneath its longest river. China has just launched a huge self-developed tunnel boring machine (TBM) to build this major tunnel, Xinhua News reported. The tunnel will serve as a crucial road link across the river, connecting the cities of Haimen in Nantong and Taicang in Suzhou, stretching over about 24.3 miles, including a 6.96-mile underwater section beneath the Yangtze River.

The Jianghai TBM has a 16.6 meter diameter and weighs a massive 5,000 tonnes. The Haitai Yangtze River Tunnel is set to be a motorway with six lanes going in both directions with a speed limit of 62 mph.

The project is expected to be completed by 2028 and plans to improve the links between Nantong and Taicang by creating a major road link across the river.

The tunnel plans to reduce the travel time between both cities.

Located in Jiangsu Province, Haimen is located in the northeastern part Haimen, and is a smaller, industrial city with a growing role in manufacturing and transportation while Taicang, located further south, is known for being close to Shanghai and has a more established port, making it a key hub for international trade and commerce.

According to the Information Office of Nantong Municipal People’s Government, the tunnel will connect Haimen and downtown Shanghai in just half an hour and it will take only 40 minutes for Haimen to reach other major cities in southern Jiangsu.

You Shaoqiang, chief engineer of the tunnel project of China Railway 14th Bureau, told Xinhua: "This project will play a pivotal role in promoting regional integration within the Yangtze River Delta and inject significant momentum into the high-quality development of the world-class Yangtze River Delta city cluster."

However, he did add that the construction process is 'extremely challenging', due to having to navigate through geological formations beneath the riverbed with a huge amount of pressure of up to 75 tonnes per square meter.

The TBM is reportedly fitted with advanced technology, including a pressure-balanced cutterhead to manage the pressure and an intelligent monitoring system for real-time tracking.

Manager of the tunnel project, Chen Junwei, said: "The tunnel boasts multiple pioneering features in structural design, disaster prevention, equipment, green technology, and intelligent systems, with its construction designed to be close to carbon neutral."