The world's longest underwater high-speed rail tunnel has completed the shield machine tool replacement under pressure.

On the 17th, at a depth of 80 meters on the Ningbo side of the Jintang subsea tunnel of the Yongzhou Railway, builders completed the inspection and replacement of 104 shield tunneling tools under a water pressure of 7.8 bar over 21 days. This marks the successful completion of a long-duration, ultra-high-pressure practical test of Chinas independently developed saturated pressure entry technology, further enhancing the countrys construction capability for deeply buried subsea tunnels.