China builds high-speed rail tunnel 89 meters under Yangtze River

Eighty-nine meters beneath the Yangtze River, China's domestically developed "Linghang," the world's largest-diameter high-speed-rail shield tunneling machine, is accelerating excavation work on a 14-kilometer tunnel to enable high-speed trains to travel under the river.

On Sunday, the shield machine completed the 11.18-kilometer underwater section of the Chongming‑Taicang Yangtze River Tunnel, setting a new record for continuous excavation exceeding 11 kilometers using a 15-meter-class large-diameter shield machine.

Measuring 148 meters in length and weighing approximately 4,000 tonnes, "Linghang" is equipped with advanced technologies including an intelligent excavation system and a high water-pressure sealing system.

To overcome challenges such as the river's vast width, extreme water pressure and complex geological conditions, engineers deployed an integrated intelligent control platform featuring a full-process digital twin of the excavation and real-time early warning, enabling the machine to safely navigate high-risk zones such as the main shipping channel and environmentally sensitive areas.

Once completed, the tunnel will allow high-speed trains to cross the Yangtze River without reducing speed, significantly boosting transport capacity. The project is a key section of the Shanghai-Chongqing-Chengdu high-speed railway and is expected to play a major role in advancing regional integration in the Yangtze River Delta.