Engineers in China are controlling a 442-foot-long tunneling machine called Yongzhou from a center about two miles away. The machine is digging part of the Jintang undersea railway tunnel between Ningbo and Zhoushan. Cameras and sensors track its work and send warnings when problems develop, while workers remain onboard to supervise operations.
Yongzhou has advanced more than 4,000 meters from the Ningbo side, completing about 83 percent of its planned digging. It is approaching a section 93 meters below the seabed. Engineers expect the machine to reach the deepest section by the end of 2026.
Hard rock and soft soil make the work difficult, especially where the machine encounters both together. About 4,000 cutting tools have already been replaced. Repairs require workers to enter a high-pressure environment. A special pressurized living chamber allows them to stay for up to 28 days and work in shifts, reducing the need to repeatedly adjust to changes in pressure.
The Jintang tunnel is about 10 miles long. The railway is expected to open in 2028, bringing rail service to Zhoushan. Once it opens, the high-speed train journey between Ningbo and Zhoushan is expected to take 26 minutes.
