The entire three levels of the tunnel boring machine have been ... the still to be found workers are either buried in the prohibited zone where the machine and silt almost reach to the tunnel ...

Here's how the tunnel boring machine, or TBM, works: As the 200-ton TBM moves forward, a round cutter head studded with titanium teeth grinds into the tunnel face and splits large chunks off the rock.

The machine is used in the construction of the Haitai Yangtze River Tunnel in East China's Jiangsu province. The tunnel is a ...

This spot, as well as the others indicated by the dogs, were on the rock fall debris that buried the tunnel boring machine (TBM ... rescuers will get back to digging. “By Sunday morning ...