SEATTLE — Crews have found damage in the seal system that protects the core components of the world’s largest tunneling machine. Officials said Friday they’re still assessing the best way to get the machine helping build a new highway tunnel under Seattle moving again.
It’s unclear when operations can resume. The machine has been mostly idle for two months, raising increased concerns that the troubled project will bust its $1.4 state billion budget. The total viaduct replacement is estimated to be a $3.1 billion project.
The machine, named “Bertha,” is only one-tenth of the way toward completing a 1.7-mile tunnel. The tunnel will carry Highway 99 traffic and allow the removal of the aging Alaskan Way Viaduct along the Seattle waterfront.
On Friday, the state Department of Transportation said inspections conducted in January found that many of the cutter-head openings were clogged with dirt and other debris. State transportation officials said that late that month, they also discovered damage to the seal system protecting Bertha’s main bearing. This was revealed after “higher-than-normal heat sensor readings” appeared.
“The main bearing is what allows the cutter head to spin,” WADOT said, adding that tunnel contractor and other experts are working with the Bertha’s manufacturer to fix the problem.
Todd Trepanier, WADOT’s administrator for the Alaskan Way Viaduct replacement program, said it was too soon to say what effect Bertha’s problems would have on the project’s price tag.
“Anything about costs would be speculation,” he said.
In 2009, the Legislature approved the tunnel project, and they included a provision requiring Seattle to pay for any cost overruns. Legal experts have said enforcing that requirement would be difficult, noting that the language of the amendment was vague.
Transportation Secretary Lynn Peterson has noted that there’s a $200 million risk-reserve fund for the project. The tunnel project is slated to be finished in late 2015.