On July 15, two domestic large shield machines with a diameter of 10.69m, "Huchi" and "Tongcheng," independently developed by Shanghai Tunnel Engineering Co., Ltd. for the Wusongkou Yangtze River Tunnel Project of the Shanghai-Nantong Railway, successfully rolled off the production line. These two shield machines will serve the construction of the Wusongkou Yangtze River Tunnel of the Shanghai-Nantong Railway, which is of great significance for advancing the development of sea-rail intermodal transport in the Yangtze River Economic Belt and implementing the integrated development of the Yangtze River Delta region.

The Shanghai-Nantong Railway project is an important component of the coastal railway corridor in the national medium- and long-term railway network plan. Once completed and opened to traffic, it will fill the gap in the trunk railway network in eastern Shanghai. Among them, the Wusongkou Yangtze River Tunnel Project of the Shanghai-Nantong Railway has a total length of 7.2 kilometers and will set three domestic "firsts": the first shield-tunneled passenger-freight mixed railway tunnel in soft soil areas, the first railway tunnel crossing both the Yangtze River and the Huangpu River, and the first fully enclosed inner-lined shield tunnel.

In response to the working conditions and construction difficulties of this project, the following innovative technologies were adopted:

• Powerful and worry-free shield cutterhead excavation — high-strength large alloy scraper cutters and leading cutters are used, along with replaceable ripper cutters, providing strong guarantees for passing close to buildings.

• Efficiency boosted by simultaneous thrusting and segment assembly — while the shield machine advances, the segment erector simultaneously assembles segments, greatly improving construction efficiency.

• Safe and precise segment erector guaranteed — equipped with a six-degree-of-freedom large-translation segment erector, the auxiliary assembly technology it carries can meet high-precision assembly operations. Vacuum suction cups are used for gripping, ensuring safety, reliability, and efficiency.

• Comprehensive status monitoring through data interconnection — signals collected by various sensors and detection components during shield excavation can be recorded and stored, and interconnected with computers at the ground monitoring center, enabling real-time monitoring of the shield machine's status at the ground monitoring center.