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.

After multiple delays, including a 9-month delay involving a century-old anchor, the Chesapeake Bay Bridge-Tunnel (CBBT) expansion achieved a major milestone as its tunnel boring machine reached ...

China has completed the production of its largest tunnel-boring machine ... The machine is 476 feet long and weighs about ...

A novel tunnel boring ... and to start cutting by the end of July, paving the way for the introduction of narrow-reef boring in January, by narrow-reef boring machines that will be equipped ...