Tag: Seattle viaduct

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Big Bertha’s delays have pushed back the opening of the tunnel it’s digging by 20 months…so far
Seattle’s new State Route 99 tunnel is officially 20 months behind schedule, and it’s all Bertha’s fault. The Associated Press reports Washington State Department of Transportation officials are now saying that the new tunnel being dug beneath Seattle by Big Bertha, the largest tunnel-boring machine in the world, won’t open until August 2017. And they […]
December 24, 2014
The pit being dug to access and repair Big Bertha will reach 120 feet below the surface. Credit: Washington State Department of Transportation
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
The nearly-assembled Bertha with cutterhead installed. Credit: WSDOT Flickr
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