CREG 1430 is China’s first variable-diameter shaft reaming machine

CREG 1430, manufactured by China Railway Engineering Equipment Group Co, will construct the vertical shafts for the Yongjia Pumped Storage Power Station in Zhejiang province.

With an excavation diameter of 7.23m, the machine will be used to bore a 358m-deep exhaust shaft and two 488m-deep diversion shafts. The total tunnelling distance is 1334m. The geology comprises rock, partial fault zones and a sediment-tuff interlayer. The lithology is crystal welded tuff and spherical bubble rhyolite, with an average compressive strength of 119-190MPa, and locally up to 223MPa.

For the project, CREG customised the shaft reaming machine, adopting a variable-angle conical cutterhead to facilitate rock breaking and discharging. The design also allows for assembly and disassembly in the narrow chamber.

The tunnelling process will be highly automated, with the operator controlling and monitoring all operations from the control cabin.

Once completed, the Yongjia Pumped Storage Power Station will provide energy storage and emergency back-up for the Zhejiang electricity grid, reducing reliance on coal-powered electricity generation.