- Associated Press - Saturday, June 6, 2015

SEATTLE (AP) - Seattle Tunnel Partners has begun installing a newly designed seal system for the world’s largest tunnel-boring machine.

State transportation officials say crews lowered the new outer seal ring into place this past week. The ring is the first new piece to be installed in the tunneling machine known as Bertha.

It’s the first step toward putting Bertha back to work under downtown Seattle.

Transportation officials say the new the new seal system will be easier to access for fixing future problems.

Seattle is building a tunnel to replace the Alaskan Way Viaduct, which was damaged in a 2001 earthquake. After the machine broke down in 2013, crews spent much of 2014 digging an access pit to reach the front of the machine so it could be pulled out and repaired.



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