On August 25, the ultra-small turning radius open-type TBM "Tianzishan" jointly built by CRCHI and China Railway 14th Bureau Group rolled off the production line in Changsha, Hunan. The equipment will be put into the construction of the gravity drainage tunnel and drainage gallery tunnel of the Hunan Shuangpai Tianzishan Pumped Storage Power Station project.

Yang Hongyu, General Manager of Hunan Shuangpai Pumped Storage Co., Ltd., Liang Erbin, Deputy General Manager of the Tunnel Company of China Railway 14th Bureau Group, Liu Yongkui, Deputy General Manager and Chief Engineer of the Second Company of China Railway 14th Bureau Group, and Liu Shaobao, Member of the Standing Committee of the Party Committee and Deputy General Manager of CRCHI, attended the event.

It is understood that the "Tianzishan" TBM has an excavation diameter of 3.53 meters, a total length of 88 meters and a total weight of 240 tons. Based on the project's engineering characteristics, key construction difficulties and CRCHI's extensive past TBM design experience, the machine was specifically designed with an ultra-small turning radius main machine structure, a large-slope rail-bound mucking, material transport and support system, solving problems such as the ultra-small turning radius, difficult mucking on 5% large slopes and difficult support. At the same time, the equipment is also equipped with key technologies such as ultra-hard rock excavation and main machine

retreat capability, achieving a daily advance of more than 30 meters, which will greatly shorten the construction period of the gravity drainage tunnel and gallery works.

As a key implementation project of the 14th Five-Year Plan under the national "Medium- and Long-Term Development Plan for Pumped Storage (2021-2035)", the Hunan Shuangpai Tianzishan Pumped Storage Power Station has a total installed capacity of 1.4 million kilowatts. After being completed and put into operation, it will mainly undertake tasks such as peak shaving, valley filling, energy storage, frequency regulation, phase modulation, emergency accident reserve and black start for the Hunan power grid, further enhancing the regulation capacity of the Hunan power grid and playing an important role in building a new energy system and promoting economic development.