Zhejiang completes 637-meter shaft, setting four industry records
The No. 1 shaft of the Zhejiang Songyang Pumped Storage Power Station has been fully connected, reaching a depth of 637 meters. This achievement marks the deepest shaft in China's pumped storage industry and simultaneously sets four new industry records.
The construction team used China's first full-section reaming ultra-deep shaft boring machine, known as "Tiangong," and applied an innovative one-time forming method for slag expansion support. Data shows the shaft's maximum deflection rate was only 0.216‰, far better than the industry standard of 0.5‰. The maximum deviation of the well diameter after expansion was just 6 mm, both indicators leading the industry.
Efficiency records were also broken. The project achieved a maximum daily excavation of 20.18 meters, a maximum monthly excavation of 236.96 meters, and a monthly average of 204.98 meters. Excavation and support of the ultra-deep shaft were completed in only 2.5 months, setting four simultaneous records for speed and precision.
The Songyang Pumped Storage Power Station is designed to house four reversible pump turbine generator sets, each with a capacity of 350,000 kW. The first unit is scheduled to begin operation in 2027, contributing to China's growing renewable energy infrastructure.
The Three Gorges Group, one of China's largest state-owned enterprises, is responsible for the project. Established in 1993, the company is best known for building and operating the Three Gorges Dam, the world's largest hydroelectric power station. Today, it plays a central role in China's renewable energy expansion, managing hydropower, wind, and solar projects across the country. Its expertise in large-scale engineering projects has positioned it as a global leader in sustainable energy development.
