en.Wedoany.com Reported - On July 17, the ultra-large diameter shield machine "Pioneer," jointly developed by China Railway Construction Heavy Industry (CRCHI) and China Railway 14th Bureau Group, rolled off the production line in Changsha, Hunan. The equipment will be used for the Wuxi-Yixing intercity rail transit project (Xi-Yi S2 Line). This is the second tunneling machine customized by CRCHI for China's first ultra-large diameter shield tunnel crossing Taihu Lake, following the "Xi Yi."
The "Pioneer" shield machine has an excavation diameter of 14.02 meters, a total length of approximately 112 meters, and a total weight of about 3,200 tons. Its cutterhead coating incorporates elements of peach blossoms and Taihu Lake water patterns.
To address the construction challenge of bedrock intrusion in the section, CRCHI equipped the "Pioneer" with multiple technological innovations. The shield machine adopts a pressurized composite cutterhead design, equipped with various tools such as disc cutters, scrapers, edge scrapers, shell cutters, overcutters, and gauge cutters. These tools can be flexibly combined and replaced based on the geological conditions of the shield section to meet different working conditions and strata requirements. A crusher system is installed inside the shield body, capable of efficiently crushing large rocks and vigorously stirring mud blocks and gravel deposited at the bottom, preventing blockages and ensuring the long-term smooth operation of the slurry shield circulation system.
The construction section includes a bedrock protrusion zone with a total length of about 120 meters, where the uniaxial compressive strength of the rock exceeds 60 MPa, and surface settlement control is stringent. To address this condition, the "Pioneer" is equipped with a high-precision guidance system and an intelligent excavation management system. The high-power crusher system inside the shield body can efficiently crush hard rocks generated during excavation and vigorously stir deposited mud clumps and gravel, ensuring the smooth flow of the slurry circulation system and guaranteeing stable and safe tunneling in "upper-soft, lower-hard" composite strata.
Once completed, the Xi-Yi S2 Line will connect regional transportation hubs such as Shuofang Airport, Wuxi Railway Station, and Yixing High-Speed Railway Station, and will link with Wuxi Metro Line 1 and the Xi-Cheng S1 Line, forming an integrated Xi-Cheng-Yi rail transit network. It will further integrate into the rail transit network around Taihu Lake, empowering the development of the Suzhou-Wuxi-Changzhou metropolitan area and the Yangtze River Delta integration.
After rolling off the production line in Changsha, the "Pioneer" will be disassembled and transported to the Wuxi construction site via combined water and land transport, where it will be assembled, commissioned, and then begin excavation.
