May 10, 2025 marks the eleventh anniversary of General Secretary Xi Jinping's inspection of China Railway Engineering Equipment Group (CREG) and his important instruction on the "Three Transformations." Guided by the important instruction of the "Three Transformations," CREG has always relied on the confidence and courage to break boundaries, working hand in hand with partners to overcome technical bottlenecks, extending from single application scenarios to complex application scenarios, and evolving from single isolated products to a full spectrum of diversified products. Through innovations in underground engineering equipment, it continues to reconstruct the boundaries of human exploration of deep underground space and advance toward the deep space of the Earth. On the occasion of the ninth "China Brand Day," we will launch a special report series on the spectrum-based application of three major scenarios, showcasing the technological breakthroughs of "Created in China" under extreme working conditions.

Green development is the underlying color of high-quality development. In recent years, guided by the "dual carbon" goals, China's green and low-carbon energy transition has continued to advance, the new-type power system has been accelerated in its construction, and the share of new energy has continued to rise. The installed capacity and power generation of wind, photovoltaic, and other "new energy" power generation facilities have increased year by year. At the same time, the characteristics of new energy—"relying on the weather" and "unstable" output—have also brought enormous challenges to the safe and stable operation of the power grid and power dispatch. Against this background, pumped storage hydropower stations, with advantages such as mature technology, large energy storage scale, and controllable costs, have become "super power banks," playing a good role in promoting the consumption of new energy and building a reliable safety barrier for the country's energy transition.

▲ China's first pumped storage hydropower station built using the TBM method—Wendeng Pumped Storage Hydropower Station

No storage, no wind and solar. Today, the construction of China's pumped storage hydropower stations is advancing vigorously with unprecedented enthusiasm and speed. However, limited by the particular characteristics of pumped storage hydropower stations—large-scale underground caverns and numerous tunnels—the drill-and-blast method is mainly used in construction, which has low construction efficiency, high safety risks, poor working conditions, and great interference with adjacent projects. How to improve the level of mechanized construction of pumped storage hydropower stations, accelerate construction progress, and shorten the construction cycle has become an urgent problem to be solved at this stage.

As the "national team" in China's underground engineering equipment field, CREG has strengthened scientific and technological and equipment innovation in response to the common difficulties in tunnel construction for pumped storage hydropower stations, injecting new "equipment momentum" into the high-quality development of the pumped storage industry. Since 2019, various types of tunnel boring machines from CREG have "shown their prowess" in major pumped storage projects across the country. With the hard-core performance of efficient excavation and precise construction, they have made positive contributions to promoting a new revolution in pumped storage hydropower station construction. From major national equipment to livelihood projects, CREG is empowering green development with "equipment intelligent manufacturing" and contributing Chinese wisdom to the realization of the "dual carbon" goals!

Breaking through ultra-small turning radii and opening a new era of pumped storage excavation

▲ The world's first small-section ultra-small turning radius TBM, the "Wendeng"

"Flexible turning" opens up new markets. In 2019, CREG undertook the research and development of a small-diameter TBM and carried out pilot application with the machine under the Shandong Wendeng project "Research and Application of Key Technologies for Mechanized Construction of Underground Tunnel Excavation in Pumped Storage Hydropower Stations." In September of the same year, the world's first compact ultra-small turning radius hard rock TBM, the "Wendeng," rolled off the production line, and in September of the following year it completed the TBM construction tasks for the pressure steel pipe gallery of the middle horizontal tunnel and the drainage gallery of the middle and lower levels of the powerhouse at the Wendeng Pumped Storage project. This marked the first application of domestically produced TBM technology in a pumped storage project, filling a gap in the industry. Since then, standardization of cavern design, route optimization, operating regulations, quotas, and research on TBMs for multiple scenarios in pumped storage hydropower stations have gradually become trends.

The ultra-small turning radius TBM is like a "steel earthworm that can turn," breaking through the construction bottlenecks of complex geology with "small radius, great energy" and turning flexibly within narrow mountains (with a minimum turning radius of only 30 meters). It maximally solves the problems of difficult construction, high risk, and slow progress in small caverns of pumped storage hydropower stations, reduces construction safety risks, improves process quality, ensures excavation progress, and improves the construction environment. The excavation speed is usually about five times higher than that of the drill-and-blast method.

▲ The world's first large-diameter ultra-small turning radius TBM, the "Funing"

Starting from the successful breakthrough of CREG's world's first ultra-small turning radius TBM, the "Wendeng," and then to the successful application of a series of "turning" TBMs such as the "Jiguang," "Luoning," and "Funing," the innovative achievements have been applied in 36 major pumped storage projects across the country, including Luoning in Henan, Funing in Hebei, Nanning in Guangxi, and Jinyun in Zhejiang. They comprehensively cover underground horizontal tunnel projects of pumped storage hydropower stations such as gravity drainage tunnels, drainage galleries, access tunnels, ventilation tunnels, and exploration adits, significantly improving the intrinsic safety level and physical quality of underground cavern projects and truly realizing "mechanized replacement of personnel and automated efficiency improvement." With core technological advantages, they continue to promote the mechanized upgrading of the pumped storage industry and support a new revolution in green energy construction.

Tackling large-inclination inclined shafts and leading new breakthroughs in water conveyance tunnels

A pumped storage hydropower station consists of an upper reservoir, a lower reservoir, water conveyance channels, a powerhouse, and a switchyard. Among these, the water conveyance inclined shaft between the upper and lower reservoirs is the "throat" of the pumped storage hydropower station, undertaking the core mission of efficiently transferring tens of thousands of tons of water energy between the upper and lower reservoirs.

▲ China's first large-diameter, large-inclination inclined shaft TBM, the "Yongning"

"Inclined upward" opens up new fields. In August 2022, the "Yongning," China's first large-inclination, large-diameter inclined shaft hard rock boring machine developed by CREG, officially rolled off the production line and was applied to two water conveyance inclined shafts of the Luoning Pumped Storage Hydropower Station. As a "major national equipment" filling the technical gap in China's large-inclination inclined shaft construction field, the "Yongning" overcame world-class challenges such as anti-slip protection at large inclinations and material transportation, and with its efficient excavation capability pushed China's pumped storage hydropower station construction toward a new stage of mechanization and intelligence.

In September 2024, the "Yongning" TBM achieved precise breakthrough in No. 2 water conveyance inclined shaft of the Luoning Pumped Storage Hydropower Station in Henan, realizing full-line breakthrough of the two "throat" tunnels of the Luoning Pumped Storage project. During construction, the "Yongning" TBM continuously "climbed" to new speeds, setting new domestic records of 22.75 meters per day and 331.065 meters per month, and further optimized the traditional three-stage structure of upper inclined shaft, middle horizontal tunnel, and lower inclined shaft for water conveyance into a one-stage inclined shaft scheme, creating a new model for the construction of pumped storage hydropower stations in China.

From the rollout of the "Yongning" to the full-line breakthrough, it not only broke the barriers of traditional drill-and-blast construction, but also provided important reference for subsequent domestic TBM construction in complex large-inclination environments. It will further promote the mechanized construction process of pumped storage hydropower station construction and inject new momentum into the transformation and upgrading of the construction management of pumped storage hydropower station projects.

Innovating a new model of shaft construction and advancing from single projects to multiple fields

▲ China's first variable-diameter shaft raise-boring machine, the "Zhumeng"

In February 2025, the "Zhumeng," China's first variable-diameter shaft raise-boring machine independently developed by CREG, successfully completed the excavation task in the 358-meter-deep exhaust shaft project of the Yongjia Pumped Storage Hydropower Station, pioneering intelligent shaft excavation in China. The "Zhumeng" achieved a cumulative excavation of 325.5 meters, with construction efficiency 3 to 5 times higher than the traditional drill-and-blast method and a fastest single-day excavation of 16.8 meters, setting a world record for the daily advance of shaft boring machines. Its pioneering innovative method of "directional drilling + raise drilling + raise-boring machine reaming" realized simultaneous construction of multiple processes such as excavation, support, mucking, and guidance, bringing the excavation quality of the water conveyance system of the Yongjia Pumped Storage Hydropower Station to the industry's top level.

▲ The world's first full-face hard rock shaft boring machine, "China Railway 599"

Behind this breakthrough is the accumulation of more than ten years of independent innovation by CREG. Since launching research on shaft equipment in 2011, CREG spent nearly 11 years and successfully developed the world's first full-face hard rock shaft boring machine, "China Railway 599," in 2021. The equipment achieves vertical downward 90-degree excavation, integrates traditional shaft construction with the concept of full-face tunnel boring, and for the first time realizes powered sinking, unmanned underground excavation, and surface remote control. It reduces construction personnel by more than 50% compared with traditional methods and improves excavation efficiency by more than two times, providing a new example for the technical challenge of full-face excavation of kilometer-level shafts.

From "China Railway 599" to the "Zhumeng," CREG, with the determination of "sharpening a sword for ten years," continues to advance into deep underground space and break through the "no-man's land" of shaft boring technology. It provides reference for promoting the comprehensive mechanization and intelligent transformation of shaft construction in pumped storage hydropower stations, and also provides complete sets of intelligent equipment and innovative construction solutions for the construction of deep and large shafts in subsequent fields such as water conservancy projects, mining development, and transportation infrastructure.

At present, China's water conservancy development has entered a new stage. Taking the eleventh anniversary of the important instruction of the "Three Transformations" as an opportunity, CREG will seize the momentum, develop more high-quality products, serve the construction of more key water conservancy and hydropower projects, continue to provide comprehensive mechanized solutions for the construction of pumped storage hydropower stations, and inject surging equipment power into the realization of the "dual carbon" goals.