en.Wedoany.com Reported - On July 30, the Chongtai Yangtze River Tunnel on the Shanghai-Chongqing-Chengdu High-Speed Railway, undertaken by China Railway Tunnel Group under China Railway, achieved a key milestone as the "Linghang," the world's largest diameter high-speed railway shield machine independently developed by China, successfully arrived at No. 2 shaft on the south bank of the Yangtze River, completing its crossing of the river and setting a world record of 11.325 km of continuous single-head tunneling by a 15-meter-class large-diameter shield machine. This tunneling achievement lays the foundation for high-speed trains to cross the river at 350 km/h without deceleration.
The tunneling equipment used for the connection between the tunnel and the shaft was jointly developed by China Railway Tunnel Group and China Railway Equipment under China Railway Industry. The "Linghang" shield machine, advancing horizontally, features a cutter head diameter of 15.4 meters and is equipped with the I-TBM intelligent control system, enabling millimeter-level alignment control. The "Qiming," which previously completed the excavation of No. 2 shaft, is the world's largest diameter shaft boring machine, with an excavation diameter of 24 meters and a shaft depth of 56.08 meters.
The Chongtai Yangtze River Tunnel is a critical control project of the Shanghai-Chongqing-Chengdu High-Speed Railway, connecting Chongming in Shanghai with Taicang in Jiangsu. With a total length of 14.25 km, it integrates five extreme construction conditions—ultra-long distance, ultra-large diameter, ultra-high speed, ultra-deep water pressure, and ultra-large shafts—making it the highest-standard and largest-scale high-speed railway river-crossing tunnel project currently under construction.
Facing the complex geology and high water pressure challenges at the Yangtze River estuary, the project team innovatively applied a "nine major intelligent" construction technology system, integrating intelligent sensing, intelligent prefabrication, intelligent tunneling, and intelligent management, and built a three-in-one multi-layer protection system of "sealing, grouting, and intelligent monitoring." The team successfully traversed major risk areas including the Yangtze River levee, the main navigation channel, and the national aquatic germplasm resources conservation area for the Chinese knife fish, passing through the deepest point of 89 meters beneath the riverbed. The relevant intelligent construction technologies have been documented in the China Shield/TBM Intelligent Tunneling Blue Book.
After the "Linghang" arrives at No. 2 shaft, it will undergo comprehensive full-dimensional inspection and maintenance, laying the groundwork for the subsequent second launch and the completion of the full tunnel connection.
Once the tunnel is completed, travel time from Chongming via Taicang to Baoshan in Shanghai will be reduced to 17 minutes, rewriting the history of Chongming Island lacking high-speed rail access and supporting the development of the "Yangtze River Delta on Rails."
