By Jonathan Kaminsky
OLYMPIA, Washington (Reuters) - A damaged drilling machine built to bore an expressway tunnel beneath Seattle will be out of commission months longer than initially thought, officials said on Monday, marking the latest blow to a key component of a major downtown revitalization project.
The delay is the latest setback to the $1.35 billion tunneling project, which ground to a halt in December when the machine, 57.5 feet in diameter and nicknamed Bertha, ran into a mysterious object later determined to be one of several steel rods left underground years earlier by state transportation officials conducting an earthquake readiness study.
The machine is now expected to be back up and running by next March, Washington state transportation officials said.
"We're disappointed by this delay, but believe the schedule is moving in the right direction," the Washington State Department of Transportation (WSDOT) said in a statement.
Once completed, the tunnel will replace a rickety above-ground highway along the downtown Seattle waterfront in what is part of a larger $3.1 billion roadway overhaul.
Only about 1,000 feet of the tunnel - about 11 percent of its full length - had been dug when the steel rod intervened.
The latest delay was announced after the project contractor, Seattle Tunnel Partners, submitted a revised timeline, state transportation officials said.
Despite what will be at least a 16-month setback, the tunnel is expected to open to the public in November 2016, which was the state's initial target date, said WSDOT spokeswoman Laura Newborn.
Seattle Tunnel Partners in its proposal to secure the contract planned to open the tunnel in late 2015, a target it will not reach.
Repairing the machine's main bearing and seal system, damaged by the steel rod, will first require digging a hole 80 feet wide and 120 feet deep to access it. The hole is expected to be completed by October, Newborn said.
The tunnel project has been politically charged, with project opponents voicing concerns that the public will be on the hook for cost overruns. But the transportation department has insisted that any potential red ink will be the responsibility of the contractor.
"Nothing that's been presented to us to date indicates that taxpayers will bear additional costs," Newborn said.
(Editing by Dan Whitcomb and Cynthia Osterman)