Bertha, the underground cutter tunneling under Seattle as part of the SR 99 Tunnel Project, has ground to a halt again and won't be back to work until Seattle Tunnel Partners (STP) proves to the state they know what they are doing.
Washington Governor Jay Inslee has ordered WSDOT to suspend STP's operations citing STP’s analysis of the January 12 sinkhole event did not sufficiently address the cause of these incidents or specify how they would prevent them from occurring in the future. The sinkhole has been filled with 250 cubic yards of concrete
An online update from the state listed five general criteria STP must meet for the suspension to be lifted, among them: “All necessary training for staff on the tunneling machine is complete.”
WSDOT said STP must confirm that:
- The tunneling machine is operating as intended and meets the design-build contract’s technical requirements.
- All necessary training for staff on the tunneling machine is complete.
- The tunneling work plan is updated to address the issues that led to the sinkhole.
- Processes are in place to ensure STP’s tunneling work plan is followed.
- STP updates its quality program to ensure key quality program managers are involved in all tunneling activities.
A clause in the $1.35 billion contract allows the state to suspend tunneling to correct unsafe conditions for workers or the public. STP manager Chris Dixon argues that Bertha should immediately restart and regain its momentum for the next 250 feet, until reaching Safe Haven 3, a concrete-lined rest stop.
Mike Lindblom's article discusses Bertha's delays and cost over runs of $143 million here:
Source: Seattle Times