The world's largest-diameter shield tunneling machine, tailored for high-speed railway projects and developed domestically in China, successfully holed through an underwater tunnel traversing the Yangtze River on Thursday.
The breakthrough will allow a high-speed train to run beneath the Yangtze River at a full speed of 350 km per hour without slowing down for the first time, marking a landmark progress in China's river-crossing railway tunneling technology.
With a total length of 14.25 kilometers, the tunnel connecting Shanghai's Chongming District and Taicang City in neighboring Jiangsu Province is built according to the highest construction standards among China's high-speed rail river-crossing projects, while ranking among the most technically challenging mega infrastructure works of its kind.
Li Bin, chief engineer of the tunnel project with China Railway Tunnel Group Co., Ltd., noted that the 148-meter-long shield machine weighs around 4,000 tonnes and features a 15.4-meter ultra-large cutter head, making it the world's largest-diameter tunneling equipment for high-speed railway construction.
The unmanned tunneling gear achieved a single continuous underwater drive of 11.325 kilometers under the Yangtze, setting a new domestic record for 15-meter-level shield tunneling.
The full completion of the entire tunnel is scheduled by the end of 2026. Once put into operation, the project will end the island district of Chongming's lack of high-speed rail access, and cut travel time from Chongming via Taicang to Shanghai's Baoshan Railway Station to just 17 minutes, significantly improving regional transportation connectivity.
China's mega tunneling machine completes Yangtze River underwater tunnel breakthrough
Chinese Premier Li Qiang emphasized advancing agricultural modernization and ensuring food security when making investigation in northeast China's Heilongjiang and Jilin provinces from Monday to Wednesday.
In Heilongjiang Province, Li, also a member of the Standing Committee of the Political Bureau of the Communist Party of China Central Committee, visited a state farm and observed the growth of soybean, corn, and rice crops. He stressed that autumn grain accounts for the bulk of annual output, calling for stepped-up farmland management and policy support to ensure grain harvest.
Visiting an agricultural science park and a rice research institute, Li asked about seed breeding innovation and black soil conservation, highlighting the importance of science and technology in pursuing higher yields and calling for further efforts in seed breeding, advanced machinery, and smart farming.
At a major water conservancy project, Li reviewed construction progress, urging faster completion to improve flood control, irrigation, and ecological benefits while supporting stable, high-yield harvests.
In Jilin Province, Li visited an agricultural cooperative and learned about its operations. He called for developing diverse forms of appropriately scaled agricultural operations and improving services for agriculture to help smallholders connect with modern agriculture.
At a grain processing plant, Li inspected a corn oil production line and called for boosting intensive processing of agricultural products to extend industrial chains and raise value.
Li also visited the Chagan Lake and learned about the ecological fisheries. He called for actively developing modern eco-aquaculture, promoting integrated development of the farming, forestry, livestock, and fishing industries as well as the development of eco-tourism.
Chinese premier stresses agricultural modernization, food security
