Tunnel-Boring

Big Alma is one of two boring machines used to tunnel under the streets of San Francisco to construct the new Central Subway to Chinatown. Big Bertha, Seattle's infamous tunnel borer, has been stalled since December. Big Alma emerged on June 11.
Jun 16, 2014   The San Francisco Examiner
Though Seattle's giant tunneling machine remains stuck 60 feet under South Main Street, muck is starting to be flung above the surface. An email from Washington's Transportation Secretary reveals concerns over the conduct of the machine's operators.
Jan 21, 2014   The Seattle Times
Is it a giant rock? What about a sunken ship? Beneath Seattle's waterfront, a mysterious object has halted Bertha, the world's largest tunnel-boring machine. Stumped engineers are unclear on how long a highway tunneling project will be suspended.
Dec 20, 2013   The New York Times
Fearing years of costly disruption from the construction of a key link connecting the region's rail systems, some of downtown L.A.'s largest property owners are suing the Metropolitan Transportation Authority.
Dec 18, 2012   Los Angeles Times