Tag: SR 99 tunnel: Page 2

Construction Equipment

Excavation stopped on Big Bertha repair pit due to major ground sinkage in area

The latest in a long string of delays to affect tunnel-boring machine Big Bertha has far greater implications than any of the others, this time threatening the structural integrity of the Alaskan Way viaduct and nearby buildings in the Seattle neighborhood of Pioneer Square. According to a report from The Seattle Times, Washington State Department of Transportation officials […]

December 15, 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

Big Bertha, world’s largest tunnel-boring machine, arrives in Seattle

The “Big” in Bertha’s name isn’t there for the catchiness. It’s there because it’s apt. With a 57-foot diameter and a length of a football field, Big Bertha is the world’s largest tunnel-boring machine. She’s quite hefty too. Bertha is assembled from 41 parts, the largest of which weighs in at 900 tons. And she […]

April 4, 2013