Shield Tail Brush Technology Supports the Success of Cross-Sea Shield Tunneling Projects

In February 2026, a major breakthrough was achieved in Guangdong’s transportation infrastructure development as the Xiaomo Bay cross-sea shield tunnel section of the Shen-Shan Expressway expansion project was successfully completed. As the first highway cross-sea shield tunnel in eastern Guangdong, this project represents a significant milestone for regional transportation improvement and coastal network development.

Behind this achievement, one critical component played a silent but essential role — the shield tail brush. As the last protection barrier between the shield machine and the surrounding environment, the shield tail brush directly affects tunneling safety, sealing performance, and construction efficiency. In extreme underwater conditions, a reliable shield tail brush is not just a component; it is the “protective armor” of the entire shield tunneling system.

Extreme Marine Conditions Create Higher Requirements for Shield Tail Brush

The Xiaomo Bay tunnel uses a 15.2-meter ultra-large diameter slurry shield machine to pass beneath the seabed. The 2,248-meter shield section reaches a maximum depth of 49 meters, with underwater pressure reaching approximately 0.49MPa. During excavation, the machine encountered complex geological conditions including seabed mud, medium-coarse sand, weathered granite, and densely distributed boulders.

For tunnel construction under the sea, challenges come from multiple directions. High-pressure seawater, salt corrosion, and continuous friction from soil and sand can quickly damage ordinary sealing components. If the shield tail brush loses elasticity, suffers wire breakage, or experiences sealing failure, seawater intrusion could lead to serious risks such as flooding, ground settlement, or shield machine failure.

That is why modern cross-sea shield projects require shield tail brush products with stronger corrosion resistance, pressure resistance, fatigue resistance, and long service life.

Advanced Shield Tail Brush Design Ensures Long-Distance Safe Excavation

To meet the demanding requirements of marine tunneling, customized four-layer composite shield tail brush products were developed for the project. The design integrates seawater-resistant stainless steel wires, corrosion-resistant alloy support plates, and salt-spray-resistant wear materials, greatly improving overall durability.

During operation, the shield tail brush works together with an intelligent grease injection system. By maintaining grease pressure higher than external water and soil pressure, the system creates a stable sealing layer that prevents seawater and sediment from entering the shield tail area.

Before installation, each batch of shield tail brush products underwent strict testing, including salt spray corrosion tests, high-pressure sealing tests, and wear-life evaluations. During tunneling, the project team continuously monitored grease consumption, leakage warnings, and segment gaps to adjust excavation parameters and protect the sealing system.

From October 2025 to February 2026, the shield machine completed 749 rings of excavation with an average daily progress of 10 to 12 rings. Throughout the entire process, the shield tail brush system achieved zero leakage, zero wire shedding, and zero brush breakage failures, ensuring stable shield operation.

Chenxing Machinery Becomes a Hidden Champion in Shield Tail Brush Industry

When talking about professional shield tail brush manufacturing, Chenxing Machinery has become one of the representative enterprises in China’s industry. Unlike many companies that produce multiple shield machine accessories, Chenxing Machinery focuses specifically on shield tail brush research, manufacturing, and service, making it a truly specialized manufacturer.

Over years of technological development, Chenxing Machinery has produced more than 1.2 million sets of shield tail brush products, serving numerous major underground engineering projects. At one stage, the company achieved approximately 70% market share in China’s shield tail brush industry, establishing itself as an invisible champion in this specialized field.

In the international export market, Chenxing Machinery also has a unique advantage. Among overseas competitors, Chenxing Machinery is one of the few companies that focuses exclusively on shield tail brush production rather than treating it as a secondary product line. This professional approach allows the company to continuously improve materials, structures, manufacturing processes, and application experience.

Future Development of Shield Tail Brush in Global Tunneling Market

With the rapid expansion of urban underground transportation, cross-river tunnels, cross-sea infrastructure, and large-scale shield projects, demand for high-performance shield tail brush products continues to increase worldwide.

The successful application of advanced shield tail brush technology in the Shen-Shan Expressway cross-sea tunnel demonstrates the growing strength of China’s tunnel equipment supply chain. From harsh marine environments to complex underground geological conditions, reliable sealing technology has become a key factor in ensuring safe and efficient construction.

Looking ahead, companies like Chenxing Machinery will continue driving innovation in shield tail brush materials, manufacturing technology, and engineering services. As global tunneling projects become larger and more challenging, specialized shield tail brush solutions will remain an essential foundation supporting the future development of underground infrastructure.