World's largest vertical shaft boring machine deployed for cross-river railway tunnel

The world's largest-in-diameter automated vertical shaft sinking machine, Qiming, was launched on Tuesday in Taicang of Jiangsu province, which commenced operations on the No 2 vertical shaft of the Chongming-Taicang Yangtze River tunnel project.

Standing 13 meters tall with a cutting diameter of 24 meters, Qiming can operate at depths of up to 75 meters and withstand water pressure of eight bar. The machine's deployment follows significant progress in the project, with the Linghang shield tunneling machine having already completed over 10,000 meters of tunneling.

The 14.25-kilometer Chongming-Taicang Yangtze River tunnel — featuring three vertical shafts and connects Shanghai's Chongming district with Jiangsu's Taicang city — represents one of China's biggest cross-river railway projects to date.

The No 2 shaft, situated 200 meters from the Yangtze River's south embankment, serves as a critical reception and relaunch point for Linghang. With a diameter of 24 meters and a depth of 56.08 meters, its construction faces significant challenges due to high groundwater levels and complex geological conditions.

"The construction of the No 2 shaft is time-critical," Fu Bowei, deputy project manager from China Railway Tunnel Group Co, said. "With Linghang approaching after completing over 10,000 meters of tunneling from Chongming's No 3 shaft, any delay could halt tunneling operations."

Qiming features advanced technological capabilities and can perform autonomous sinking, directional control, and environmental monitoring through its intelligent systems for adaptive excavation, precise self-guidance, and automatic parameter adjustment.

The machine's supervised unmanned operation capability marks an advancement in vertical shaft construction, transitioning from conventional methods to an intelligent construction model that minimizes human presence both above and below ground.

This innovation also addresses traditional challenges in deep shaft construction, particularly in areas of visual inspection, physical access, and precise measurement.

Upon completion, the Chongming-Taicang Yangtze River tunnel will enable high-speed trains to maintain their speed while crossing the river. The project holds particular significance for Chongming island — China's third-largest island — which previously lacked high-speed rail connectivity.

The tunnel project represents a crucial step in enhancing the Yangtze River Delta region's integrated transportation network, supporting both the Yangtze River Economic Belt and regional integration efforts.