Tag: biggest tunnel-boring machine

Roadbuilding

PHOTOS: Fixing Bertha: How workers dug a 12-story pit to raise world’s largest tunnel boring machine from the dead

No. 8 Story in 2015 « No. 9 No. 7 »   [imagebrowser id=194] The Big Bertha saga recently received a major update: crews with lead contractor Seattle Tunnel Partners have finished digging the 120-foot pit that will be used to access the world’s largest tunnel boring machine for necessary repairs. Now that the pit […]

February 11, 2015

Construction Equipment

Drilling delays a problem for tunnel-boring machine Big Bertha even as she slumbers below ground

Crews in Seattle are now expected to finish digging a 12-story pit to reach stalled tunnel-boring machine Big Bertha one month later than planned due to concrete pilings proving more difficult to drill through than expected, according to a report from the Seattle Times. Bertha, the world’s largest tunnel-boring machine went down from overheating in late January, […]

July 31, 2014

Construction Equipment

Repairs to Big Bertha will include 86 tons of steel reinforcement to tunnel-boring machine’s bearing, cutter drive

The largest tunnel-boring machine in the world needs a bit of reinforcement against the “wet and abrasive soils” deep below Seattle, according to a report from the Seattle Times. As such, repairs for Big Bertha will include the installation of 216 steel ribs and plates that will add 86 tons to the 7,000-ton machine, the paper […]

June 18, 2014