China's largest slurry tunnel boring machine (TBM) rolls off the production line in Zhengzhou, capital of central China's Henan Province, Sept. 29, 2018. The machine has a diameter of 15.8 meters, ...

China's largest slurry tunnel boring machine rolls off the production line in Zhengzhou, capital of Central China's Henan province, on Sept 29, 2018. [Photo/VCG] ZHENGZHOU -- China's largest slurry ...