When WSDOT posted this image on January 7, officials explained, "On Jan. 5, 2014, crews started drilling 5-foot-diameter metal shafts in front of the Bertha, the SR 99 tunneling machine. These shafts are being installed where earlier probing detected metal in front of the machine. The plan is to further identify the limits of any metal in front of the machine and remove as much of the metal as possible." Now that tunneling begins again, the state still doesn't report finding any metal or obstructions.
The Washington State Department of Transportation announced on its website last night that after nearly seven weeks of being stalled, Bertha, their cutesy name for a tunnel-boring machine, will resume churning through earth later this week. What was in her way? Why was she stopped? Did the various inspections reveal what the problem was? They don't say:
Seattle Tunnel Partners is expecting to restart operations of the SR 99 tunneling machine this week.
Crews will finish inspections of the excavation chamber and cutterhead by the morning of Tuesday, Jan. 28. This will mark the completion of the hyperbaric intervention work at this time. As of Sunday evening, Jan. 26, crews had performed 36 hyperbaric interventions, totaling 134 hours over 10 days...
While we understand the interest in knowing the reasons why mining was stopped in December, it will take time to review the results of the hyperbaric interventions and consult with tunneling experts advising WSDOT. We will continue to provide the public with information as we have it and work with the contractor to ensure that the machine is ready to begin mining under downtown Seattle.
Regular updates will be provided this week when new information is available.
This was not a cheap delay. Yesterday I posted a massive document that accounted for the project's estimated schedules and costs. One Slog reader named psbirch calculated that the cost per business day on this project was about $252,424. (For their part, WSDOT spokespeople deny that daily cost, but they have yet to provide an alternative cost per day.)
Regardless of the exact cost, IT WAS DAMN EXPENSIVE TO KEEP THAT MACHINE DOWN THERE DOING NOTHING, never mind the additional costs of drilling massive shafts for soil inspection and hyperbaric work to investigate the problem. So even after these expensive delays, the state still is not saying what brought Bertha to a halt. They don't report finding any obstructions. Perhaps they'll reveal what the problem was in the future, or, more concerning, maybe the state doesn't know.