Jan. 10 update: Exploratory shaft work continues
Yesterday afternoon, drilling of an exploratory shaft indicated the possible presence of an object in front of Bertha, the SR 99 tunneling machine. To explore further, a crew member was lowered approximately 60 feet down into the shaft. His visual inspection was inconclusive. Additional inspections are taking place today.
Crews have completed drilling three of four shafts being used to further identify the limits of any metal in front of the machine and remove as much of it as possible. If no objects are detected or removed from the shafts, the shafts will be filled to form part of an underground barrier that will create a safe environment for workers to enter the machine’s excavation chamber.
It’s still too early to determine the cost or long-term schedule implications of this issue. We’ll continue to work with Seattle Tunnel Partners to determine ways to make up time lost during the blockage. Our focus is now on addressing this issue safely and in a timely manner so we can resume tunneling as soon as possible.