The holiday season provided some rest for Bertha, the tunnel-boring machine roughly three-quarters of the way through its route to bore a new State Route 99 tunnel under downtown Seattle, but that doesn’t mean crews have had it so easy.
January 2016 was supposed to signify a new beginning for “Bertha,” the world’s largest tunnel-boring machine that now sits under downtown Seattle with its 57.5-ft-dia cutterhead motionless.
