Excavation ‘super shield’ to bore first train tunnel under Yangtze River in Shanghai

A giant boring-machine shield, designed to excavate a 7.74km (4.81-mile) underwater tunnel for the new Chongming metro line in Shanghai, was put into position on September 12, 2022, on Changxing island, to begin work on the latest metro line for the city. The new line will be the first to go under the Yangtze River in Shanghai. It will connect the Shanghai mainland to the neighbouring river island of Chongming, the third-largest island in China, via the much smaller Changxing Island. It will add to the city’s large and complex metro system that has 20 lines covering 830km (515.7 miles).