CRCHI(SH:688425) Yang Shi Wang·2025-10-25 13:40Core Viewpoint - The article emphasizes the importance of developing "national heavy equipment" as a key strategy for China to achieve high-level technological self-reliance and leadership in new productive forces during the "14th Five-Year Plan" period, showcasing significant advancements in the manufacturing of large-scale tunneling machines like the "Jiang Hai" shield machine [1][20]. Group 1: Technological Advancements - The "Jiang Hai" shield machine, developed by China Railway 14th Bureau and China Railway Construction Heavy Industry Group, has a maximum excavation diameter of 16.64 meters, specifically customized for the Hai Tai Yangtze River Tunnel project [5][11]. - The Hai Tai Yangtze River Tunnel, which connects Nantong and Taicang, is 11.185 kilometers long, with the shield tunnel section measuring 9,315 meters, making it the world's longest underwater highway shield tunnel [5][20]. - The "Jiang Hai" machine incorporates advanced technologies such as a real-time monitoring system for the main bearing and an intelligent segment assembly robot, enhancing its automation and digital capabilities [16][20]. Group 2: Engineering Challenges - The "Jiang Hai" machine faces significant engineering challenges, including high water pressure and deep excavation, with a maximum depth of 75 meters and water pressure exceeding 7.5 bar [14][15]. - The development team innovated a constant pressure tool replacement technology to address the difficulties of changing tools under high pressure, which is critical for the machine's operational efficiency [15][20]. - The machine's main bearing, considered its "heart," is designed for a lifespan of over 20,000 hours, with a diameter of 8.6 meters, representing the largest of its kind in the shield machine sector [14][20]. Group 3: Industry Growth and Market Position - China's shield machine industry has achieved a global market share of 70%, with products exported to over 40 countries and regions, reflecting a significant leap in the manufacturing capabilities during the "14th Five-Year Plan" [20][22]. - The industry has seen rapid growth in the number of large-diameter shield machines, with advancements in technology and applications extending beyond traditional uses to include underwater and deep space projects [22][23]. - The article highlights the shift from reliance on foreign brands to domestic production, showcasing the evolution of China's manufacturing capabilities in this sector over the past two decades [18][20].