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The world’s smallest-diameter shield tunneling machine independently developed by China Railway Engineering Equipment Group Co., Ltd (CREG) rolled off the assembly line on March 31 in Shanghai, China. With a diameter of 7.5 meters and atmospheric pressure cutter disk, the machine was named “Changtong” and will be used in the Yangtze River underwater tunneling project of the China-Russia East Route Natural Gas Pipeline. The project is the world’s largest through-river tunneling task in terms of single tunneling distance, digging depth, water pressure, and tunnel diameter. (By Sun Kaidi)