A 135-metre-long machine is digging part of China’s Jintang undersea railway tunnel, which connects Ningbo and Zhoushan. Engineers guide the machine, named Yongzhou, from a control centre above ground about two miles away. Workers remain on board to supervise operations.
Cameras and sensors monitor the machine’s cutting equipment and progress. The system also sends warnings directly to engineers’ smartphones when it detects problems. Yongzhou has advanced more than 4,000 metres from the Ningbo side, completing about 83 per cent of its planned excavation.
The machine is approaching a section 93 metres below the seabed, where conditions are becoming more difficult. Its route includes hard rock, soft soil and places where it cuts through both together. Around 4,000 cutting parts have already been replaced. To carry out repairs under high pressure, technicians use a special pressurised chamber where they can live between work shifts.
Yongzhou will eventually meet Dinghai, a second machine digging from Zhoushan, and both will be taken apart inside the tunnel. The complete tunnel is 16.18 kilometres long. The Yongzhou Railway is expected to open in 2028, bringing rail services to Zhoushan. It will reduce the high-speed train journey between Ningbo and Zhoushan to 26 minutes.
