Bertha, the world’s largest tunneling machine, has been stuck under downtown ... causing it to overheat and stop drilling—a mundane problem that brought the entire project to a standstill.

SEATTLE — The world’s largest tunnel-boring machine broke through a concrete ... broke down soon after it started drilling in 2013 and didn’t crank up again until last year.

Bertha, the world’s largest tunnel boring machine (TBM), started digging under Seattle on Tuesday as it chewed through the north wall of the 80-ft (24.3 m) deep trench where it was assembled ...

It’s been two months since the world’s largest tunnel boring machine stopped drilling underneath Seattle, but now Washington’s Department of Transportation has a better idea of what’s ...

The world’s largest-diameter tunnel boring machine (TBM) is travelling all the way from Osaka ... Sound Transit often has fellow TBMs drilling under Seattle’s hills. Next up, Northgate to the ...

As the first large-slope tunnel-boring machine in the world, the so-called Beishan No 1 will be used in the construction of an underground laboratory to research disposal technologies for high ...

China has completed the production of its largest tunnel ... have developed the world’s first boring and blasting machine ...

It can remove up to 8.5 million cubic feet of earth per day. Big Bertha is the world's largest tunnel-boring machine. It was used to build the Gotthard Base Tunnel in Switzerland, the longest and ...

The video showed the drilling machine in operation and the damage it had done to the tunnel and the rails. The drill pierced through ceiling of the tunnel and went all the way down to the rails of ...