Tunnel boring machine Dinghai unveiled in C China

The tunnel boring machine (TBM) Dinghai, with a maximum excavation diameter of 14.57 meters, was officially unveiled in Changsha, central China's Hunan Province on Wednesday.

Weighing 4,350 tonnes, this TBM will be used in the construction of the world's longest undersea high-speed rail tunnel, which is the Jintang undersea tunnel linking the Jintang islet of Zhoushan and the coastal area of Ningbo in Zhejiang.

(Reported by Xiang Yipeng;　Edited by Wang Xiaoting)