Following the successful launch of 'Nanhu', the world's largest rectangular shield machine on April 10, 2020, 'Wendeng', the world's first ultra-small turning radius hard rock TBM, made its first section transmission today at the upper corridor of 887m. Independently developed by CREG and applied in Wendeng Pumped Storage Power Station Project in Shandong undertaken by State Grid Xinyuan Company, 'Wendeng' TBM is also the first case in China where hard rock full cross-section tunnel boring machine (TBM) construction is adopted in the construction of pumped storage power stations.

Tailored for pumped storage power stations, 'Wendeng' TBM has a length about 37m and an excavation diameter of 3.53m; it occupies a space only about 80% of the conventional equipment, with a turning radius of 30m, which is one-tenth of the conventional TBM for maximizing flexibility and maneuverability. The entire equipment can turn around by 60 degrees during the tunneling process, providing excellent extra safety, higher tunneling efficiency, strong adaptability and flexible transition in tunnel construction.

From its launching on October 13, 2019 to its transmission at the upper corridor on April 14, 2020, 'Wendeng' TBM has achieved a maximum daily drill footage of 20.548m for the straight section and 11.165m for the curved section. The circular tunnel is composed of four turning sections of R30m. It is an ultra-small limit turning radius tunnel for tunneling in China, which requires solving the world’s toughest problems such as the flexibility of equipment turning in small curves, and belt deviation, etc.

The application of 'Wendeng' TBM has introduced new ideas to the engineering design, construction and construction management of the project. It is also a milestone for the high-quality development of the TBM industry and the mechanization of tunneling in China.