Tag: Washington State Route 99 tunnel

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

Construction Equipment

Tunnel-boring machine Big Bertha moves forward 2 feet in test run to see if blockage is fully removed

After nearly two months of downtime caused by a steel pipe stuck in her teeth, Big Bertha, the world’s largest tunnel-boring machine, briefly went back to work beneath Seattle. According to a report from the Associated Press, the Washington State Transportation Department announced that Bertha moved two feet on Tuesday which was just enough progress […]

January 30, 2014

Construction Equipment

A steel pipe is what brought Big Bertha, the world’s largest tunnel-boring machine, to a halt

The mystery is solved—in part at least. After Big Bertha, the world’s largest tunnel-boring machine, was brought to an abrupt halt on December 6th, officials at the Washington State Department of Transportation were stumped as to what was in the way. Now they know that the obstruction is a large steel pipe. A steel pipe […]

January 6, 2014

Construction Equipment

Big Bertha, world’s largest tunnel-boring machine, lowered into starting position in Seattle

With the digging of the Washington State Route 99 tunnel in Seattle scheduled to start in July, the Washington State Department of Transportation recently lowered the head of Big Bertha, the world’s largest tunnel-boring machine, into the pit that will serve as its starting position. Bertha made her triumphant arrival in Seattle at the beginning of April […]

June 5, 2013