Recently, the first domestic tail seal 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 domestically produced tail seal brushes has reached the domestic leading level, while their 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. Tail seal 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 tail seal can easily lead to water and grout leakage, and may even cause tunnel collapse; therefore, the quality of the seal 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 domestic version of the tail seal brush in 2012 and currently produces more than 10,000 tail seal brushes per year.

　　In recent years, China Railway Tunnel Group has invested heavily in research and development of shield supporting equipment, established a shield cutterhead production workshop, realized the localization of shield supporting equipment, and worked hard 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 under the National 863 Program and 973 Program. 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 can not only produce 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 industrial chain from research and development and construction to manufacturing and remanufacturing.