Tunnel boring machine "Dinghai" exceeds 5,000 meters at Jintang undersea tunnel in Zhejiang

Technicians operate at the control room of the tunnel boring machine "Dinghai" in Zhoushan, east China's Zhejiang Province, Nov. 28, 2025. China's self-developed tunnel boring machine "Dinghai" exceeded a tunneling mileage of 5,000 meters on Friday at the Jintang undersea tunnel between cities of Ningbo and Zhoushan in east China's Zhejiang Province.

The milestone marks the completion of over 80 percent of the tunneling workload in Zhoushan section of Jintang undersea tunnel.

The tunnel, stretching 16.18 km, is an crucial part for the Yongzhou (Ningbo-Zhoushan) high-speed railway, and is set to be the world's longest undersea railway tunnel upon completion. (Xinhua/Huang Zongzhi)

A worker assembles a segment ring inside the tunnel boring machine "Dinghai" in Zhoushan, east China's Zhejiang Province, Nov. 28, 2025. China's self-developed tunnel boring machine "Dinghai" exceeded a tunneling mileage of 5,000 meters on Friday at the Jintang undersea tunnel between cities of Ningbo and Zhoushan in east China's Zhejiang Province.

The milestone marks the completion of over 80 percent of the tunneling workload in Zhoushan section of Jintang undersea tunnel.

The tunnel, stretching 16.18 km, is an crucial part for the Yongzhou (Ningbo-Zhoushan) high-speed railway, and is set to be the world's longest undersea railway tunnel upon completion. (Xinhua/Huang Zongzhi)

Technicians conduct remote management through the "digital twin" platform of the Jintang undersea tunnel on the Yongzhou Railway in Zhoushan, east China's Zhejiang Province, Nov. 28, 2025. China's self-developed tunnel boring machine "Dinghai" exceeded a tunneling mileage of 5,000 meters on Friday at the Jintang undersea tunnel between cities of Ningbo and Zhoushan in east China's Zhejiang Province.

The milestone marks the completion of over 80 percent of the tunneling workload in Zhoushan section of Jintang undersea tunnel.

The tunnel, stretching 16.18 km, is an crucial part for the Yongzhou (Ningbo-Zhoushan) high-speed railway, and is set to be the world's longest undersea railway tunnel upon completion. (Xinhua/Huang Zongzhi)

Workers pose for a group photo inside the tunnel boring machine "Dinghai" in celebration of the machine exceeding a tunneling mileage of 5,000 meters in Zhoushan, east China's Zhejiang Province, Nov. 28, 2025. China's self-developed tunnel boring machine "Dinghai" exceeded a tunneling mileage of 5,000 meters on Friday at the Jintang undersea tunnel between cities of Ningbo and Zhoushan in east China's Zhejiang Province.

The milestone marks the completion of over 80 percent of the tunneling workload in Zhoushan section of Jintang undersea tunnel.

The tunnel, stretching 16.18 km, is an crucial part for the Yongzhou (Ningbo-Zhoushan) high-speed railway, and is set to be the world's longest undersea railway tunnel upon completion. (Xinhua/Huang Zongzhi)

Technicians mark the 2,500th segment ring in the Jintang undersea tunnel of the Ningbo-Zhoushan Railway, as the tunnel boring machine exceeds a tunneling mileage of 5,000 meters in Zhoushan, east China's Zhejiang Province, Nov. 28, 2025. China's self-developed tunnel boring machine "Dinghai" exceeded a tunneling mileage of 5,000 meters on Friday at the Jintang undersea tunnel between cities of Ningbo and Zhoushan in east China's Zhejiang Province.

The milestone marks the completion of over 80 percent of the tunneling workload in Zhoushan section of Jintang undersea tunnel.

The tunnel, stretching 16.18 km, is an crucial part for the Yongzhou (Ningbo-Zhoushan) high-speed railway, and is set to be the world's longest undersea railway tunnel upon completion. (Xinhua/Huang Zongzhi)

A technician checks operation inside the tunnel boring machine "Dinghai" in Zhoushan, east China's Zhejiang Province, Nov. 28, 2025. China's self-developed tunnel boring machine "Dinghai" exceeded a tunneling mileage of 5,000 meters on Friday at the Jintang undersea tunnel between cities of Ningbo and Zhoushan in east China's Zhejiang Province.

The milestone marks the completion of over 80 percent of the tunneling workload in Zhoushan section of Jintang undersea tunnel.

The tunnel, stretching 16.18 km, is an crucial part for the Yongzhou (Ningbo-Zhoushan) high-speed railway, and is set to be the world's longest undersea railway tunnel upon completion. (Xinhua/Huang Zongzhi)