BEIJING, Jan. 30, 2026 — China Railway Construction Corporation (CRCC) is making progress on several undersea tunnel projects spanning the Bohai, Yellow, East, and South Seas. These initiatives are utilizing domestically developed technologies to overcome complex geological and engineering challenges, with the goal of improving regional connectivity along China’s extensive coastline.
Off the coast of Ningbo in the East China Sea, the Yongzhou Railway’s Jintang undersea tunnel is currently under excavation, reaching depths of approximately 78 meters. CRCC engineers are employing China’s first integrated shield tunneling system, which features pressurized face operations. This system is designed to manage high water pressure and facilitate safe, remote-controlled maintenance and cutter replacement, addressing key technical limitations in the construction of ultra-long and ultra-deep undersea tunnels in China.
In the northern region, the 17.48-kilometer Qingdao Jiaozhou Bay Second Tunnel is under construction, utilizing a combination of shield tunneling and conventional mining techniques. This approach allows for safe passage through areas with alternating hard rock and fractured ground. Meanwhile, in the south, the Shenzhen-Jiangmen Deep River undersea tunnel is progressing at depths of up to 116 meters, making it one of the world’s deepest high-speed rail tunnels situated beneath the sea.
The Jinpu Sea River Tunnel in the Bohai region, a component of the Jinan-Qingdao high-speed rail line, has been successfully completed. This project successfully navigated challenges posed by highly corrosive saline soil and complex river-sea intersection zones through the implementation of specialized anti-corrosion measures and precise engineering controls, ensuring the long-term operational integrity of the large-scale shield tunneling equipment.
CRCC has established a comprehensive technical framework that encompasses survey and design, construction management, critical components, and digital operations, extending from equipment manufacturing to smart construction practices. With numerous cross-sea tunnel projects advancing steadily, improvements in transportation connectivity along China’s coastal areas and the overall level of regional integration are anticipated.
Company: China Railway Construction Corporation Limited
Contact Person: Zhang Jing
Email: zhangjing@crcc.cn
Website: https://english.crcc.cn/
Telephone: 010-52688232
City: Beijing, China
A photo accompanying this announcement is available at
