On September 26, the world’s largest-diameter shaft boring machine “CREC Qiming,” jointly developed by China Railway Tunnel Group and China Railway Hi-Tech Industry under CREC, rolled off the production line in Zhengzhou. The machine will be deployed for the construction of Shaft No. 2 of the Chongming–Taicang Yangtze River Tunnel for the Shanghai–Chongqing–Chengdu High-Speed Railway.
The Chongming–Taicang Yangtze River Tunnel links Chongming District in Shanghai with Taicang City in Jiangsu Province. The tunnel stretches 14.25 kilometers in total, making it the longest, largest, and most technically advanced high-speed railway river-crossing tunnel in China. The shield tunneling section extends 13.25 kilometers and includes three vertical shafts, with Shaft No. 2 located within a planned country park in Taicang City, approximately 200 meters from the south embankment of the Yangtze River.
As China’s largest domestically developed shaft boring machine, “CREC Qiming” features an ultra-large cross-section and deep underwater excavation capability, with a cutting diameter of 24 meters and a maximum excavation depth of 150 meters. The machine adopts a dual-arm structure integrating excavation, muck removal, and guidance functions, and is equipped with innovative technologies such as attitude adjustment and settlement control. It demonstrates strong geological adaptability, high-precision attitude control, and accurate strata recognition.
At present, construction of the Chongming–Taicang Yangtze River Tunnel is progressing steadily. The previously launched “CREC Linghang,” the world’s largest-diameter shield tunneling machine for high-speed railways, has safely reached the deepest point of the underwater tunnel 89 meters below the Yangtze River and continues to advance toward the river’s southern bank. It will eventually meet “CREC Qiming” underground in a remarkable engineering convergence.
