Recently, the "Kaolu Xianfeng" (Pathbreaker Pioneer) super-large-diameter slurry balance shield machine, jointly developed by CRCC Heavy Industry and China Railway 14th Bureau Group, helped the Guangzhou Haizhu Bay Tunnel Project—the first super-large-diameter municipal shield tunnel in the Pearl River Basin—achieve smooth double-line breakthrough. On this occasion, the "Kaolu Xianfeng" shield machine started later but broke through first, representing a "cornering overtake" in domestic shield machine technology.

The Guangzhou Haizhu Bay Tunnel Project is Guangzhou's ** super-large-diameter shield tunnel, known as the "Guangzhou ** Shield." The route has a total length of 4.35 kilometers, of which the shield-driven section is 2,077 meters. It crosses a fracture zone and the Pearl River shipping channel twice, traverses mudstone and argillaceous siltstone strata over long distances, and passes beneath dense building clusters and pile groups. It features a complex construction environment, many factors controlling excavation, and high construction difficulty, placing extremely high demands on the shield machine.

In response to the above major engineering challenges, the CRCC Heavy Industry R&D team carried out a series of targeted designs for the "Kaolu Xianfeng" to ensure safe and rapid excavation by the shield machine.

The "Kaolu Xianfeng" shield machine has an excavation diameter of 15.07 meters, a total length of 130 meters, and a total weight of 4,300 tons. From the first component being lowered into the shaft for assembly on February 20, 2023, all processes from shield machine assembly to launch were completed in less than 3 months. It was launched 2 months later than the west-line shield machine and completed the east-line excavation task of the Haizhu Bay Tunnel in 12 months, breaking through 1 month earlier than the west-line shield machine. During excavation, CRCC Heavy Industry provided the customer with full-process support services from equipment installation and commissioning through tunnel breakthrough. During excavation of the "Kaolu Xianfeng" shield machine, the maximum daily advance was 16 meters and the maximum monthly advance was 324 meters. The equipment's excellent performance was highly recognized by the customer and the owner.