World's longest undersea high-speed railway tunnel in China's Zhejiang under construction

A technician works in the "Yongzhou" shield tunneling machine in the Jintang undersea tunnel of Ningbo-Zhoushan Railway in east China's Zhejiang Province, Feb. 11, 2026. The Jintang undersea tunnel, stretching 16.18 km, is an important facility for the Yongzhou (Ningbo-Zhoushan) high-speed railway and is set to be the world's longest undersea high-speed railway tunnel upon completion.

So far the "Yongzhou" shield tunneling machine has achieved a tunneling mileage exceeding 3,146 meters. (Xinhua/Huang Zongzhi)

A technician monitors the construction through the smart management platform of Jintang undersea tunnel of Ningbo-Zhoushan Railway in east China's Zhejiang Province, Feb. 11, 2026. The Jintang undersea tunnel, stretching 16.18 km, is an important facility for the Yongzhou (Ningbo-Zhoushan) high-speed railway and is set to be the world's longest undersea high-speed railway tunnel upon completion.

So far the "Yongzhou" shield tunneling machine has achieved a tunneling mileage exceeding 3,146 meters. (Xinhua/Huang Zongzhi)

A technician works in the "Yongzhou" shield tunneling machine in the Jintang undersea tunnel of Ningbo-Zhoushan Railway in east China's Zhejiang Province, Feb. 11, 2026. The Jintang undersea tunnel, stretching 16.18 km, is an important facility for the Yongzhou (Ningbo-Zhoushan) high-speed railway and is set to be the world's longest undersea high-speed railway tunnel upon completion.

So far the "Yongzhou" shield tunneling machine has achieved a tunneling mileage exceeding 3,146 meters. (Xinhua/Huang Zongzhi)

Technicians monitor the construction through the smart management platform of Jintang undersea tunnel of Ningbo-Zhoushan Railway in east China's Zhejiang Province, Feb. 11, 2026. The Jintang undersea tunnel, stretching 16.18 km, is an important facility for the Yongzhou (Ningbo-Zhoushan) high-speed railway and is set to be the world's longest undersea high-speed railway tunnel upon completion.

So far the "Yongzhou" shield tunneling machine has achieved a tunneling mileage exceeding 3,146 meters. (Xinhua/Huang Zongzhi)

A technician works in the "Yongzhou" shield tunneling machine in the Jintang undersea tunnel of Ningbo-Zhoushan Railway in east China's Zhejiang Province, Feb. 11, 2026. The Jintang undersea tunnel, stretching 16.18 km, is an important facility for the Yongzhou (Ningbo-Zhoushan) high-speed railway and is set to be the world's longest undersea high-speed railway tunnel upon completion.

So far the "Yongzhou" shield tunneling machine has achieved a tunneling mileage exceeding 3,146 meters. (Xinhua/Huang Zongzhi)

This photo taken on Feb. 11, 2026 shows the construction site of Jintang undersea tunnel of Ningbo-Zhoushan Railway in east China's Zhejiang Province. The Jintang undersea tunnel, stretching 16.18 km, is an important facility for the Yongzhou (Ningbo-Zhoushan) high-speed railway and is set to be the world's longest undersea high-speed railway tunnel upon completion.

So far the "Yongzhou" shield tunneling machine has achieved a tunneling mileage exceeding 3,146 meters. (Xinhua/Huang Zongzhi)

A technician works in the "Yongzhou" shield tunneling machine in the Jintang undersea tunnel of Ningbo-Zhoushan Railway in east China's Zhejiang Province, Feb. 11, 2026. The Jintang undersea tunnel, stretching 16.18 km, is an important facility for the Yongzhou (Ningbo-Zhoushan) high-speed railway and is set to be the world's longest undersea high-speed railway tunnel upon completion.

So far the "Yongzhou" shield tunneling machine has achieved a tunneling mileage exceeding 3,146 meters. (Xinhua/Huang Zongzhi)