Crews drill to look for an obstruction in front of the tunnel-boring machine on Seattle's waterfront. Credit: Washington State Department of Transportation
While it's certain that the machine digging the Highway 99 tunnel under downtown Seattle did grind to a halt last month shortly after hitting a steel pipe, plenty of mystery still surrounds the idled earthmover and the future of the multi-billion dollar megaproject.
Lingering questions about the cause and cost of the machine’s stoppage were on full display Monday, as state Secretary of Transportation Lynn Peterson and Washington State Department of Transportation staffers briefed the Seattle City Council.
The WSDOT representatives said it was still too early to know much about the price of the delays or whether the pipe was the only problem afflicting the machine, known as Bertha. Peterson also discussed WSDOT's decision to hold Seattle Tunnel Partners — the contractor group running the project — in breach of contract for failing to give an adequate amount of work to minority and women-owned companies.
WSDOT program administrator Todd Trepanier acknowledged that WSDOT and Seattle Tunnel Partners were under "a lot of presssure" to estimate the cost of the stop-down and when the machine would get moving again. “It would be irresponsible at this time," he said, "for us to really speculate on all those issues."
The machine has bored about 1,000 feet of the 1.7-mile long tunnel. WSDOT representatives said the contractor and the agency expected the first 1,500 feet of digging to be a “shakedown cruise.” But on Dec. 3, the tunneling machine hit an 8-inch diameter, 119-foot long, steel well-pipe left in the ground by a WSDOT contractor in 2002. In the days that followed, the machine began to experience increased resistance moving forward. The current boring stoppage began on Dec. 7.
The well site was noted in planning documents for the project, but a Seattle Tunnel Partners project manager said recently that the pipe should have been removed when the well was decommissioned.
Matt Preedy, WSDOT Alaskan Way Viaduct Replacement Program deputy administrator, said on Monday that probing the ground in front of the machine had not helped to confirm the root of the tunneling machine’s troubles.
“All of our ground investigation out in front of the machine has been inconclusive,” he said.
Trepanier said the pipe might not be the only problem. “I think maybe that is a contributing factor," he said. "But there are other issues that are being dealt with and wanting to be understood at this point in time on why this machine stopped.”
There have been difficulties, he said, with material not flowing correctly through the machine and wear to its metal teeth, which weigh about 1,200 pounds each.
“I don’t necessarily agree with the word stuck,” Trepanier said later, referring to Bertha’s current status. “The cutter head turns, you can mine with this machine. It would be like driving in your car and the warning light is coming on and telling you to stop.”
Regardless of whether the machine is stuck or stopped, the delays are raising concerns in Seattle. A provision in the state bill financing the project says that any costs beyond $2.8 billion will be paid for by “property owners in the Seattle area who benefit from replacement of the [Alaskan Way Viaduct] with the deep bore tunnel.”
Mayor Ed Murray, who co-sponsored the bill during his time as a state Senator, says he’d like to convince legislators in Olympia to remove that language from the law.
At the briefing on Monday, council member Sally Bagshaw pressed the WSDOT representatives on what the current delays mean for the city's finances.
“You’re talking about cost overruns potentially. One thing I want to clarify is that the city of Seattle is not on the hook to pay those cost overruns,” said Bagshaw. “The city is not party to the contract between you and the state and the partners, is that correct?”
“You’re stepping into an area that is a little beyond my understanding,” replied Trepanier.
When Bagshaw asked Peterson to confirm that the city is a not part of the tunnel construction contract, the Secretary of Transportation said: “Correct.”
Peterson also said the project started with a $205 million risk reserve fund and that “a cost overrun would be above and beyond that.”
Digging began in Sodo on July 30 last year and the machine is scheduled to emerge in South Lake Union around September 2014. The tunnel is slated to be open for traffic in late 2015.
Whether that schedule will remain intact is unclear. Seattle Tunnel Partners has told WSDOT that the machine should be able to mine at a rate of about 65-feet to 72-feet per day. So far, Bertha’s biggest day was about 52-feet. In some schedules that the agency has discussed with the contractor Bertha would have to average about 39 feet each day to complete the project on time, according to Trepanier. Those schedules, he said, didn't consider tunneling 24 hours per day or seven day per week.
Determining the exact cause of Bertha’s problems is complicated by the fact that the area in front of the 57-foot wide machine is filled with groundwater. Workers have pumped-off much of that water in recent weeks.
Removing the water creates a risk that the ground above the machine could sink. Preedy, said that the agency was monitoring the ground around the viaduct and nearby buildings and that so far any movement has been minor.
The groundwater table is now low enough, he said, that by the end of the week workers might be able to enter pressurized chambers at the front of the machine, allowing them to gather new information about what's stopping Bertha.
During Monday’s meeting, Peterson also explained how WSDOT had declared Seattle Tunnel Partners in breach of contract for putting up barriers to “disadvantaged business enterprise” participation in the project. Seattle Tunnel Partners committed to awarding about 8 percent of work on the project to small businesses run by minorities and women.
The Federal Highway Safety Administration issued a report in November that said WSDOT had not made adequate efforts to insure that Seattle Tunnel Partners was meeting its disadvantaged business enterprise hiring goals.
Peterson said the sanctions could make it more difficult for the two lead contractors, Dragados and Tutor-Perini, to secure future work in Washington. Asked why WSDOT was not imposing sanctions, which would be allowed under the state’s agreement with the companies, Peterson said: “What we want to avoid is ending up in court litigating this.”
“Is this kind of like a yellow flag on the project?” councilmember Tom Rasmussen asked, referring to the contract breach. “Is this a partner that has to be watched very very closely or they’ll try to escape some of their obligations?”
Peterson said: “I think we had a lot of questions that we have put out there today about how to get Bertha ready to go the final distance.”
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