On 22 January 2018, CREG’s 8.03m Gripper TBM which is used for a 23 km tunnel broke through, marking the excavation completion of Lot 4, Yinsong Water Diversion Project in Jilin Province.

The breakthrough was celebrated by Chairman of Jilin Province Water Industry Investment Group Co., Ltd, Mr. Xu Haitao, Deputy Chief Engineer of China Railway Tunnel Group (CRTG), Mr. Zhang Wei, General Manager of China Railway Tunnel Stock Co., Ltd., Mr. Zhao Quanmin, and Deputy GM of CREG, Mr. Fang Xinqiang.

Yinsong Water Diversion Project is one of the 172 major projects included in China’s 13th National Five-year Plan (2016-2020). The project is historically significant in terms of the scale, length and scope of benefit in Jilin Province. Lot 4 is among the most complicated and difficult construction sections of the overall stretch, which requires particular care.

After launch on its first drive in May 2015, the Gripper TBM with customized design, has bored through 7.9km shall-overburden limestone karsts, fractured zone and shall-overburden ravines. Despite the massive inrush of water and slurry during its operation, the machine achieved peak monthly rate of 1318.7m, setting a record to gripper TBM performance in China. What worthy particular mention is that, the breakthrough took place 9 months ahead of schedule, representing a significant progress in the history of China’s hard rock TBM application.

The earlier breakthrough has everything to do with the excellent organization of the tunneling contractor CRTG. And the project turns out to be a valuable addition to CRTG’s rich construction experience, especially with long-distance and particularly challenging tunneling.