Recently, the domestically first shield tail sealing brush wear-resistance testing platform independently developed by China Railway Tunnel Group was put into use. Experimental testing and actual on-site use show that the performance of the domestically produced shield tail sealing brush has reached the domestic leading level, while its cost is only one-third that of similar foreign products.

　　The shield tunneling machine is an internationally advanced specialized engineering machine for tunnel excavation and has been widely used in tunnel projects such as subways, railways, highways, municipal works, and hydropower. Shield tail sealing is one of the key points in forming the sealed structure of a shield, and it is an important guarantee for shield construction safety, especially for underwater and subsea tunnel construction. Failure of the shield tail seal can easily lead to water and grout leakage, and may even cause tunnel collapse; therefore, the quality of the sealing brush affects the excavation speed and effectiveness of the shield. It is understood that the Special Equipment Center of China Railway Tunnel Group successfully developed a domestically produced shield tail sealing brush in 2012, and currently produces more than 10,000 shield tail sealing brushes annually.

　　In recent years, China Railway Tunnel Group has invested heavily in research and development of shield supporting equipment, established a shield cutterhead production workshop, achieved localization of shield supporting equipment, and strived to reduce the cost of shield use. Relying on high-end platforms established by the company, such as the State Key Laboratory of Shield Machine and Boring Technology and the Henan Provincial Academician Workstation, it has undertaken multiple projects including National 863 Program and 973 Program topics. China Railway Tunnel Group is a leader in using shields for subway construction and has participated in subway construction in more than 20 cities across the country. It is not only capable of producing complete shield machines, but is also at the forefront in shield remanufacturing. It recently completed the remanufacturing of a Herrenknecht S217 shield with a diameter of 6.4 meters and cumulative excavation of 10 kilometers, forming a complete industry chain from research and development and construction to manufacturing and remanufacturing.