Get ready Pioneer Square: Bertha's about to awake from her more than year-long slumber. Her first task will be to muster enough energy to plow through the 20-foot concrete walls in her 120-feet-deep rescue pit. According to the Washington State Department of Transportation, crews will begin chipping away at the walls as early as this weekend.
Sometime next week, they will begin to run Bertha until she overheats, pause for cooling, then repeat. They will continue until the tunnel boring machine is far enough into the access pit for an enormous crane to lift the 2,000-ton cutterhead from Bertha's face to the surface for repairs. How long before we can catch a glimpse of our long-lost tunneling machine? Not sure, says WSDOT. "The duration of Bertha’s dig will depend on her ability to mine through and digest concrete while operating with a damaged seal system."
WSDOT officials did mention one other thing: an additional 1/4 inch settlement in the viaduct. They say their bridge experts aren't worried and that the viaduct is still safe; we'll see if everyone is so relaxed.
WSDOT pictures below.
