On March 28, the first dual-mode super-large-diameter TBM for the entire Jianghan Water Diversion Project successfully rolled off the production line in Changsha, Hunan, marking that the TBM for Section 8 of the Jianghan Water Diversion Project, constructed by Sinohydro Bureau 14 Co., Ltd., has entered the assembly stage, and TBM tunneling construction is about to begin.

The "Jianghan Long'an" has a designed tunneling section with a total length of 11.63 kilometers. It was jointly developed and manufactured by Jianghan Water Network Company, China Railway Construction Heavy Industry, and Sinohydro Bureau 14 Co., Ltd., and is the first and only earth pressure balance–single shield dual-mode TBM for the Jianghan Water Diversion Project. The TBM has an excavation diameter of 12 meters, an overall length of 138 meters, and an overall weight of 3,585 tons. It can adapt to different geological conditions ranging from soft to hard rock, achieve long-distance continuous tunneling, and reach a maximum tunneling speed of 80 millimeters per minute. In response to the geological characteristics of alternating soft rock deformation, fault fracture zones, and ultra-hard rock, it can flexibly switch between earth pressure balance and single shield modes, greatly improving stratum adaptability and construction efficiency, reducing personnel labor intensity, and effectively addressing risks that may exist during construction, such as water and mud inrush, soft rock deformation, fault fracture zones, and two underpasses beneath the Xiangyang–Chongqing Railway, thereby providing strong equipment support for fast, efficient, and reliable tunnel construction.

It is understood that the TBM tunneling section of Section 8 of the civil construction and metal structure and electromechanical installation of the Jianghan Water Diversion Project is about 28.25 kilometers long, and a total of 2 TBMs are used for construction. At present, the "Jianghan Long'an" TBM has completed the assembly and commissioning of all equipment and is scheduled to be transported to the on-site assembly cavern before June 2025 to start on-site assembly work.

The Jianghan Water Diversion Project of the South-to-North Water Diversion Middle Route uses a tunnel water conveyance line with a total length of 194.7 kilometers and an average annual water transfer volume of 3.9 billion cubic meters over many years. It is an important landmark project for accelerating the construction of the main framework and major artery of the national water network. Once completed, it will enable the Three Gorges Reservoir and the Danjiangkou Reservoir, two major national strategic projects, to "join hands" across space, effectively improve the water resource allocation capacity of the Hanjiang River Basin, increase the volume of water transferred northward by the South-to-North Water Diversion Middle Route Project, and create conditions for the Han-to-Wei Water Diversion Project to achieve its long-term water transfer scale.