Bertha is allowed to dig under Seattle once again.
The contractor, Seattle Tunnel Partners, has been given conditional permission to start tunneling underneath the city’s waterfront after nearly a month of halted operations.
“WSDOT, in consultation with its team of tunnel experts, lifted the suspension of tunneling for cause and said that conditional tunneling should resume for 25 more tunnel rings. I concur with their decision, and WSDOT has notified the contractor,” said Gov. Jay Inslee on Tuesday.
The permission is conditional, according to the Washington State Department of Transportation. Bertha is allowed to move ahead approximately 160 feet, and install about 25 concrete rings to continue crafting the tunnel. WSDOT will monitor the progress to see if STP can prove it can operate the machine safely. If WSDOT approves of STP’s operations, Bertha will be allowed to move ahead another 100 feet to its planned maintenance stop. That stop is the waypoint before tunneling underneath the Alaskan Way Viaduct and downtown Seattle.
STP was given permission Tuesday morning. Tunneling began at around 7 a.m. By 3:30 p.m., Bertha had moved forward about 3 feet.
Conflict between STP and WSDOT
Despite the approval to move forward, the stoppage over the past month has caused another rift between WSDOT and the tunneling contractor.
“There is a disagreement with Seattle Tunnel Partners on this. It’s not the first time we have disagreed,” said Todd Trepanier with WSDOT. “They think the stop was not appropriate, and they would like to be compensated for the time it has cost them.”
Trepanier said that if STP decides to press the issue and demand compensation, WSDOT will use dispute resolution mechanisms in the contract for the project.
Even though WSDOT is allowing STP to bore once more, barging activity — the process of shipping away excavated soils via barges in Elliott Bay — will be restricted until further procedures are developed. In the meantime, the soil will be shipped away by truck. It’s that process that has been under scrutiny after a sinkhole developed in Bertha’s wake in January.
“The contractor has a plan for modifying tunnel operations to ensure positive ground control. It has also made changes to key personnel, and it has put in place protocols for quality control and assurance,” Inslee said. “The contractor now has an opportunity to show progress during this test period, prior to tunneling under the viaduct and underneath Seattle.”
WSDOT has placed conditional changes to operations, which include:
Reorganize personnel within STP’s quality assurance department
Implement new quality assurance procedures
Personell at key tunneling positions will be changed
New daily tunneling meetings with more participants and procedures
The project to dig a tunnel to replace the SR 99 viaduct through downtown Seattle has faced a series of problems that have stopped its progress. Most recently, the machine caused a sinkhole shortly after starting up again. That start was highly anticipated after it sat idle for repairs for nearly two years.
After the sinkhole developed, the state halted all operations of the tunneling project until STP could prove the job could be done safely.