Bertha has reached her goal.
The cutterhead on Seattle's troubled tunnel machine broke through the 20-foot-thick wall of a rescue pit at about noon on Thursday. Video from a television helicopter showed a big plume of dust coming from inside the pit as the machine emerges.
State transportation officials said the boring machine moved forward about 6 feet by Wednesday night and stopped to build two concrete tunnel rings before resuming Thursday morning.
This is just the beginning of a complicated repair plan. Next, crews plan to remove the front of the balky machine and pull it out of the pit.
Gov. Jay Inslee tempered his pleasure at getting good news on the contentious highway tunneling project.
"People have to understand there is going to have to be a lot of work on this machine to get it operable,” he said. “It is great to see movement, but there's a long ways to go."
The tunnel, which will run about 2 miles under the city, is designed to replace the Alaskan Way viaduct, damaged in a 2001 earthquake. The project is two years behind schedule.
The Washington state Department of Transportation released this video of crews at work on Thursday:
https://www.youtube.com/watch?v=ln9U9DrrwFs