这里是位于江苏省长江入海口区域的海太长江隧道施工现场，进入地下几十米，穿过长长的已经拼砌好的管片内壁的隧道，我们从"江海号"盾构机的尾部进 入到"江海号"的内部。 央视网消息（焦点访谈）：党的二十届四中全会提出，"十五五"时期要加快高水平科技自立自强，引领发展新质生产力，抢占科技发展制高点。研制"大国 重器"无疑是抢占科技发展制高点的关键之举。在"十四五"时期，我国研制的"大国重器"不断"攀"高，站上了一个又一个创新制高点。天上，有"嫦娥六号"实 现全球第一次月球背面无人采样返回，有第一座中国空间站"天宫"；地下，有全球领先的超大直径盾构机正在掘进。从今天（10月25日）开始，《焦点访 谈》推出系列节目《大国重器再攀高》。我手边的两个模型，是我国自主研制的最大直径盾构机"江海号"和"沧渊号"，看着不大，但在施工现场它们是超过 五层楼高、重量超过5000吨的"钢铁巨龙"。 150米长的"江海号"内部高度超过5层楼，从尾部向前，首先是100多米的后配套系统，主要包括控制、出渣、注浆、电气、液压、导向、物料运输等多个复 杂系统。后配套系统的前面，就是"江海号"的主机核心部分，主要包括推进、管片拼装、驱动及刀盘开挖系 ...

Core 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 and beyond [1]. Group 1: Development of "National Heavy Equipment" - The "Jianghai" shield tunneling machine, developed by China Railway 14th Bureau and China Railway Construction Heavy Industry Group, has a maximum excavation diameter of 16.64 meters and is specifically customized for the Haitai Yangtze River Tunnel project [2][3]. - The Haitai Yangtze River Tunnel, which connects the Haimen District of Nantong and Taicang City of Suzhou, is 11.185 kilometers long, with the shield tunnel section measuring 9,315 meters, making it the world's longest underwater highway shield tunnel [2][7]. - The construction of the tunnel will reduce the travel time across the river from one hour to just ten minutes, utilizing a dual six-lane design with a speed limit of 100 kilometers per hour [2][3]. Group 2: Technical Innovations and Challenges - The "Jianghai" shield machine incorporates advanced technologies, including a real-time monitoring system for the main bearing and an intelligent assembly robot for segment components, showcasing a high level of automation and digitalization [5][6]. - The machine faces significant challenges, such as high water pressure and deep burial, with the maximum depth reaching 75 meters and water pressure exceeding 7.5 bar, complicating the replacement of worn-out cutting tools [4][5]. - To address the challenge of tool replacement under high pressure, the development team innovated a constant pressure tool replacement technology, which includes a high-pressure gate for each replaceable tool [5]. Group 3: Industry Growth and Global Position - China's shield tunneling machine industry has achieved a global market share of 70%, with products exported to over 40 countries and regions across five continents [7]. - The "14th Five-Year Plan" period has seen rapid growth in the production and application of ultra-large diameter shield machines, with advancements in technology and an expansion of application scenarios [7][8]. - The industry is moving towards greater excavation diameters, faster tunneling speeds, deeper excavation depths, and more diverse application scenarios, indicating a commitment to continuous innovation and leadership in the field [8].