The breakthrough has completed the full connection of two key water diversion inclined shafts, setting a new mechanised construction record in China’s pumped storage power station sector, and successfully applying a new mechanised full-section excavation model for inclined shafts.

TBM Yongning, jointly developed by CREC’s subsidiary China Railway Engineering Equipment Group, State Grid Xinyuan Luoning Company, and Sinohydro Bureau 6, completed the No. 2 shaft by tunnelling upwards at an angle of 38.742 degrees. It bored 860m of the 873m length.

The TBM began excavation on April 25. It achieved a daily tunnelling record of 22.75m and a monthly record of 332m, setting a record for inclined shaft TBM tunnelling in China.

TBM Yongning broke through on the No. 1 inclined diversion shaft in January this year.

Luoning Pumped Storage Power Station in Henan province is the largest pumped storage power station under construction in central China, with a total installed capacity of 1.4 million kW. The project involves optimising the upper inclined shaft, the middle adit and the lower inclined shaft into a primary inclined shaft, creating a new approach for the construction of pumped storage power stations in China.