On Oct 20, China's self-developed world's largest diameter high-speed railway shield machine, called Linghang, excavated its 1,000th ring segment in the construction of the Chongtai Yangtze River Tunnel on the Shanghai-Chongqing-Chengdu High-speed Railway. This tunnel, spanning 14.25 kilometers, links the island of Chongming in Shanghai with Taicang city in Jiangsu province. Upon completion, the tunnel is poised to enable seamless high-speed train crossings under the Yangtze River, holding significant importance for driving development in the Yangtze River Economic Belt, Xinhua News Agency said in a report.