On the morning of July 30th 2026, the world’s largest-diameter high-speed railway shield TBM, Linghang (Voyager), jointly developed by China Railway Tunnel Group(CRTG) and China Railway Engineering Equipment Group(CREG), successfully traversed the natural barrier of the Yangtze River and safely arrived at the No.2 shaft excavated by TBM Qiming (Illuminator), which achieves the holing-through of the underwater shield-driven section of the Chongming - Taicang Yangtze River Tunnel. Once the project is completed and put into operation, it will end the history that Chongming Island, China’s third-largest island, has no high-speed railway service.

The Chongming - Taicang Yangtze River Tunnel is a critical throat project on the Shanghai-Nanjing section of the Shanghai-Chongqing-Chengdu High-Speed Railway, one of China’s national “Two Key” Projects. It connects Chongming island in Shanghai with Taicang in Jiangsu. The tunnel has an overall length of 14.25 km and is equipped with three shafts. The underwater shield-driven section across the Yangtze River stretches from Shaft 3 on the southern bank to Shaft 2 on the northern bank, with a length of 11.325 km. It features a maximum burial depth of 89 m beneath the river bottom and an ultra-high water pressure of 0.9 MPa. With a design speed of 350 km/h, this tunnel is presently China’s cross-river high-speed rail tunnel with the highest construction standards and the greatest construction difficulties.

The design team of CREG, taking into account the technical challenges of the Chongming - Taicang Yangtze River Tunnel: extra-large diameter, ultra-long driving distance, ultra-high water pressure and maximum overburden depth, custom-developed the extra-large diameter slurry balance shield machine Linghang(Voyager). With a cutter-head diameter of 15.4 m, an overall length of 148 m and a total weight of approximately 4,000 tons, the TBM is equipped with a host of innovative technologies. It enables adaptive pressure regulation inside the shield chamber, cloud-based predictive data self-decision making, autonomous cruising along the designed tunnelling alignment, and self-adjustment of slurry circulation muck removal. Supported by full-system algorithm control, it delivers an autonomous tunnelling mode featuring “on-site attendance with no manual operation”.

For the first time beneath the Yangtze River, Linghang(Voyager) has achieved a single-head continuous tunnelling distance of over 11 km, accomplishing an unprecedented “ultra-long distance run” under the riverbed. Once the tunnel is completed and put into service, it will realize the remarkable feat of high-speed trains crossing the Yangtze River without speed reduction.

With the completion of the Chongming - Taicang Yangtze River Tunnel project, China’s national comprehensive three-dimensional transportation network will be further improved, and transport capacity will be greatly enhanced. This will in-depth energize the “Yangtze River Delta on Rail”, facilitate efficient connectivity of people flow, logistics and capital flow, boost coordinated regional development, and bring about a fundamental transformation of cross-river transportation - shifting from “detouring via ferries” to “direct high-speed rail access”.