Core Viewpoint - The construction of Wuhan's first metro ring line, Line 12, has made significant progress with the successful completion of the longest subway tunnel under the Yangtze River, marking a major milestone in the project [1][4]. Group 1: Project Overview - Wuhan Metro Line 12 has a total length of 59.9 kilometers and includes 37 stations, making it the longest metro ring line under construction in China [4]. - The line is designed to connect with 18 other lines (including planned routes), earning it the title of "King of Transfers" [4]. Group 2: Engineering Achievements - The section of the tunnel between Danshuichi Station and Science Park Station spans approximately 4011 meters, making it the longest subway tunnel crossing the Yangtze River in China [4]. - The construction utilized a shield machine named "Jiangcheng Zhuoyue," which has a diameter of 12.55 meters [4]. Group 3: Technical Challenges and Innovations - The construction team faced complex geological conditions, needing to navigate significant infrastructure such as the Wujin Pipeline Corridor, Wuchang Dike, and the main navigation channel of the Yangtze River [8]. - The project has been awarded 21 national patents and received multiple accolades, including a national-level innovation award and a gold medal in the Intelligent Construction Technology Application Competition [11]. Group 4: Impact on Urban Development - Once operational, the metro line will reduce travel time between Qingshan and Jiang'an districts to just 5 minutes, significantly alleviating passenger flow pressure in the city center [11]. - The completion of Line 12 is expected to accelerate the development of key urban areas and enhance the overall urban transportation system [11].