China has inaugurated its first urban cross-sea bridge rail line in Ningbo, a coastal city in Zhejiang province, marking a significant advance in regional infrastructure development. The new Ningbo-Xiangshan intracity rail line spans 61.45 kilometers and features 10 stations, including two underground and eight elevated platforms, connecting Ningbo’s urban center with Xiangshan county.
Operated by Ningbo Rail Transit Group Co Ltd, the line runs at speeds up to 160 kilometers per hour and is designed to enhance integration of local towns, industrial zones, and cultural tourism sites within the Ningbo metropolitan area. The route crosses the East China Sea and Xiangshan Port, providing a faster and more efficient transportation option for commuters and travelers.
A key highlight of the project is the Xiangshan Port cross-sea bridge, which stretches 8.276 kilometers and includes a main bridge section of 1,376 meters with a central span of 688 meters. This cable-stayed railway bridge is the first of its kind for an urban transit system in China and is currently the world’s largest ballastless-track bridge of its type.
Zhang Chuanbo, manager of the construction project from China Railway No 4 Engineering Group (CREC4), emphasized the engineering significance of the bridge. Its parallel position alongside an existing cross-sea highway bridge offers a distinctive visual landmark. The rail line begins at Xiaoyangjiang Station in Yinzhou district, crosses Xiangshan Port via the new bridge, passes through Xiangshan county, and terminates at Damuwan Station.
Ningbo Rail Transit Group highlighted that travel time between Ningbo’s urban area and Xiangshan county has been reduced to approximately 30 minutes, substantially improving regional connectivity.
CREC4 was responsible for major construction components, including the main rail line, wiring between Xiaoyangjiang Station and the Zhuangxi Dashan Tunnel entrance, as well as work on the Yunlong rolling stock depot lines and elevated bridge waterproofing.
According to Bai Lin, chief engineer on the CREC4 project, track laying on the cross-sea bridge began on October 6, 2025. The process posed substantial challenges due to the bridge’s close proximity—about 50 meters—to an existing highway bridge and the semi-floating design of the structure, which causes complex deformation under varying temperature and wind conditions.
Hu Jiaman, director of the CREC4 engineering division, described the precision required for installing ballastless tracks on the bridge, noting that the stringent millimeter-level tolerances needed make the work comparable to drawing a straight line on shaking paper. The new rail line represents a major achievement in China’s ongoing effort to expand and modernize urban infrastructure.