Three more loose bolts in tunnel

New problems were discovered in the Ted Williams Tunnel yesterday when state inspectors found three loose bolts holding a ceiling panel over one westbound lane. One of the bolts had pulled out of the ceiling by half an inch.

The left-hand lane in the eastern-most part of the tunnel was closed as a precaution, though westbound traffic was still allowed to go as far as the South Boston exit.

In addition, officials said that the Williams tunnel would be subject to temporary closure in the coming weeks, as engineers test the strength of the bolt-and-epoxy ceiling fixtures in the tunnel after similar fasteners gave way in a section of the Interstate 90 Connector on July 10. Officials have not determined when or for how long the tunnel -- currently open to all westbound traffic and airport buses eastbound -- would be closed.

State transportation officials also backed off previous estimates for reopening the I-90 connector yesterday, saying the engineering challenges of designing a reinforced support system for the tunnel's ceiling will require the vital downtown thoroughfare to remain closed indefinitely.

Both developments are certain to add to the traffic woes faced by commuters since the ceiling collapse killed 38-year-old Milena Del Valle of Jamaica Plain.

``It's very hard to offer any timelines at this point," said Jon Carlisle, a state Transportation Department spokesman, adding that the engineering work had proven more difficult than anticipated. ``People should know we're working as fast as possible, with safety as our top priority."

The Ted Williams Tunnel is the only other portion of the Big Dig that extensively uses bolt-and-epoxy fixtures. Visual inspections of the ceiling after the accident found 11 loose bolts in that tunnel, where the ceiling panels are lighter. But the eastbound lanes were closed for almost a day last week after state officials decided that two loose bolts holding up a single panel created a potential safety hazard.

Then yesterday, after what Carlisle said was a more thorough inspection by the state Transportation Department, three additional loose bolts were found, all holding up a single panel.

Crews brought in a special truck to temporarily support the panels until new ceiling fixtures can be added. State officials said fixing the problem could take several days.

Early last week, Governor Mitt Romney stood before cameras outside the connector and said he hoped the ramp from South Boston to the eastbound Ted Williams Tunnel would open by yesterday. He also said that the ramp connecting I-90 west to Interstate 93 would open a week or two later. On Friday, Romney said he was optimistic the South Boston ramp would open early this week.

But yesterday the South Boston ramp, known as Ramp A, was closed, with engineers still designing new ceiling supports and not a single new bolt in place.

Even as engineers worked on fixing the tunnels, it became clear yesterday that Big Dig project manager Bechtel Parson/Brinckerhoff does not face unlimited civil liability if the company is found responsible for the I-90 connector tragedy.

The maximum amount the state can possibly recover in damages against Bechtel/Parsons Brinckerhoff is $150 million, and no amount is recoverable due to loss of public use of the tunnels or loss of toll revenue, according to an agreement reached in 2001 between the state and the companies. The state could recover more if it can prove willful misconduct, gross negligence, or fraud.

``Without question, the agencies and governors who have run this project have been too close to Bechtel, and portions of these contracts clearly favor Bechtel's interests over those of taxpayers," said David Guarino, spokesman for Attorney General Thomas F. Reilly, referring to the liability cap.

In May, Reilly had negotiated a settlement with Bechtel/Parsons Brinckerhoff to settle state claims for shoddy work on the Big Dig for $85 million, but that deal was scuttled in June after US Attorney Michael J. Sullivan objected.

After the accident, inspections found more than 200 loose bolts holding up the connector ceiling, and Romney said he had lost confidence in the reliability of any of that tunnel's more than 1,100 epoxy-bolt fasteners. As a result, engineers must essentially design a new system to support its multiton concrete ceiling panels. The new system of anchor bolts will augment the existing bolts, not replace them, but the system must theoretically be able to support the entire ceiling on its own, a safety measure known as redundancy.

State engineers were still working through a complex series of calculations yesterday to determine how much weight each new bolt will carry and how ceiling panel weights will be redistributed between the old and new bolts.

The state Transportation Department is working with Kansas City-based engineering firm TranSystems, which has offices in Medford. The Federal Highway Administration must approve the design before installation can begin.

``It's hard to say when we'll get final approval and how long it will take," Carlisle said, adding that he ``couldn't speculate" on even a rough timetable. ``The schedule is really fluid."

Even when installation gets underway, progress may come in fits and starts. State officials said the presence of rebar -- the grid of reinforcing steel within the tunnel roof -- would probably slow the drilling of new bolt holes. The new ceiling bolts, which do not use epoxy, have expandable tips that embed into the concrete roof.

State officials said the installation of the bolts in Ramp A, where five problem spots were detected during inspections after the accident, will serve as a template for the rest of the connector tunnel.

Romney said last week he wanted to test the strength of a sampling of the bolts in the Ted Williams Tunnel as a precaution.

The tests, known as ``pull tests," will involve using a device to apply pressure that exceeds the weight the bolts must support.

The work cannot occur while traffic flows through the tunnel, and Carlisle said tunnel closures could begin as early as this week.

The officials are still debating whether to close the tunnel at night for short time spans and do the work piecemeal or to close the tunnel for a longer period to finish the work at one go.

Andrea Estes and Mac Daniel of the Globe staff contributed to this report.