China’s domestically developed, world's largest-diameter vertical shaft boring machine "Qiming" was officially put into operation in Taicang City of east China’s Jiangsu Province on Tuesday, for the Chongming-Taicang Yangtze River Tunnel project.

The "Qiming" shaft boring machine has a digging diameter of 24 meters, a main unit height of approximately 13 meters, and a maximum digging depth of 75 meters.

At the operation site, which is 200 meters from the south bank of the Yangtze River, the machine will dig vertically for over 50 meters to complete Shaft No.2 of the Chongming-Taicang Yangtze River Tunnel.

According to technicians, Shaft No. 2 is equivalent to a maintenance station for "Linghang", China's domestically developed, world's largest-diameter high-speed-rail shield tunneling machine, which has already excavated over 10,000 meters along the underwater railway channel.

However, the geological environment at this location is complex, posing extremely high safety risks during construction for vertical excavation.

Therefore, the "Qiming" machine is equipped with multiple innovative technologies such as tunneling self-adaptation and assembly self-synchronization, successfully solving major technical problems of invisibility, intangibility, and inaccuracy in ultra-deep water-rich composite strata.

Application of the machine promotes upgrade of ultra-deep vertical shaft construction from the traditional excavation mode to an intelligent construction mode, according to officials.

"We have adopted the operation mode of minimal manpower above ground and no manpower underground, which allows us to tunnel in both soft and hard rock earth structures. The machine can handle both very soft and rough terrains, making it highly adaptable to various geological formations," said Fu Bowei, deputy manager of the Chongming-Taicang Yangtze River Tunnel Project under China Railway Tunnel Group Co., Ltd.

The Chongming-Taicang Yangtze River Tunnel runs 14.25 kilometers in total mileage, with 13.2 km planned for boring. Once operational, it will allow high-speed trains to pass beneath the Yangtze River without reducing speed.

The Tunnel, connecting Chongming in Shanghai with Taicang in Jiangsu Province, is expected to be completed by the end of 2026. As a key project on the Shanghai-Nanjing section of the Shanghai-Chongqing-Chengdu High-Speed Railway, it will significantly reduce the travel time between cities along the Yangtze River such as Shanghai, Nanjing and Hefei.