Problems with bolts reported in 1994

More than 4 percent of ceiling anchor bolts failed strength tests after being installed in the Ted Williams Tunnel in 1994, and the company installing the drop ceiling in the tunnel complained that the problem was at least partly caused by air pockets in the concrete roof.

But Big Dig officials countered at the time that the workers were not installing the bolts correctly, according to documents obtained by the Globe.

The documents, including memoranda between Walsh Northeast and Big Dig managers, suggest that problems with the bolts, which were glued into concrete to hold up a heavy ceiling, were not uncommon. The same technique was used to hang the ceiling in the adjacent Interstate 90 connector tunnel, and the epoxy-fastened bolts have been the focus of investigators since 10 concrete ceiling panels caved in at the eastern end of the connector on July 10. The accident crushed to death a 38-year-old Jamaica Plain woman on her way to Logan International Airport.

``The epoxy, even if it's state-of-the-art, has very little tolerance for error, which calls for a much greater level of oversight," said Neil Cohen, Massachusetts' deputy inspector general, who investigated similar problems with the Ted Williams Tunnel ceiling bolts in 1998. ``We're not talking about throwing grass seed down on the golf course. This is serious stuff."

The accident has prompted the state to evaluate the safety of bolts throughout the Big Dig tunnels, and Governor Mitt Romney said yesterday that state inspectors are likely to start strength tests on a sampling of ceiling bolts in the Ted Williams Tunnel in the next day or two. If they turn up problems, redundant bolts might have to be installed throughout the tunnel.

The reopening of the tunnel's eastbound lanes to passenger cars could be delayed beyond the hoped-for Monday morning, Romney said at a morning press conference, because engineers must first devise a way to permanently secure a ceiling panel with two loose bolts. The discovery of that problem led Romney to close the eastbound lanes, which had still been open to airport-bound buses and emergency vehicles, at noon Thursday.

BOLT DOCUMENTS Read tunnel memos on boston.com/globe.

Those lanes reopened to buses at 6:50 a.m. yesterday, after workers installed scaffolding to temporarily bolster the weakened ceiling panel. State Police escorted Silver Line and Logan Express buses to make sure they safely maneuvered through the scaffolding, which partly obstructed the roadway.

That won't work for regular traffic, however. Moreover, Romney said the installation of bolts to reinforce the ceiling of the tunnel entry ramp from D Street in South Boston had not begun, because engineers were still designing the repairs.

``We had hoped that this would be complete by the end of the weekend or early next week," Romney said.

The documents obtained by the Globe concern installation of the drop ceiling near the airport end of the Ted Williams Tunnel. They include a field engineer's daily report, which said that five of 58 bolts subjected to ``pullout tests" on Dec. 16, 1994, had failed. By that date, the report said, 45 of 1,012 tested bolts had failed, or 4.4 percent.

Bernard Conway, Walsh's senior project manager in the Ted Williams Tunnel, had offered an explanation for some of the bolt failures in a memo a month earlier, saying that pores inside the concrete roof were absorbing most of the epoxy placed in drill holes. As a result, there was little glue left to hold the 5.5-inch bolts in place.

``We have seen instances in which a quarter-inch or less of epoxy has been found at the end of a failed bolt," Conway wrote to officials at Bechtel/Parsons Brinckerhoff, the firm overseeing the Big Dig tunnel projects. ``We feel that this condition merits immediate attention so as to ensure the optimum performance of the [Ted Williams] tunnel ceiling."

But Michael Ryan, resident engineer for Bechtel/Parsons Brinckerhoff, rejected the holes-in-the-concrete theory, saying in a memo to Conway that inspections showed the real problem was the quality of workmanship, not the concrete. He said Big Dig managers had seen workers drilling holes that were too deep for the bolts, causing epoxy not to fill the holes. He also said the company was not following cold weather procedures to ensure that the epoxy hardens and was applying the epoxy with a method intended for hollow masonry walls, not solid concrete.

Another document, an inspection report dated Dec. 19, 1994, said that three of 13 drill holes examined were 7 inches or deeper and that another hole had overlapped a previously drilled hole that had not been completely filled in with grout. A sheet of handwritten notes by another Bechtel/Parsons Brinckerhoff worker said that the contractor ``has no physical stops on the drills" to prevent holes from being too deep and that bolts ``are not always clean." Dirty bolts can weaken the epoxy.

And an inspection report dated Nov. 25, 1994, noted that some bolts had fallen out before the epoxy set and workers were ``using duct tape" to hold bolts to the ceiling until it set .

Ryan's memo asked Walsh to address the workmanship problems and noted that the cold weather procedures had already been modified. Ultimately, Walsh finished the Ted Williams ceiling and Bechtel/Parsons Brinckerhoff signed off on the quality of the work, clearing the way for the opening of the 1.6-mile-long tunnel in December 1995.

Walsh Northeast did not return a call seeking comment.

Asked about the documents yesterday, officials at the inspector general's office said they show that epoxy bolts are only reliable if conditions are right and workers follow all the procedures. Romney has already said that he no longer has confidence in any of the more than 1,100 epoxy bolts in the I-90 connector and the state has hired Hilti USA to provide far more durable bolts. Those undercut anchor bolts are considerably more expensive than epoxy bolts, but they are designed to hold fast in high-sensitivity places, from roller coasters to nuclear power plants.

State officials have more confidence in the epoxy-and-bolt fasteners in the Ted Williams Tunnel, largely because the ceiling panels they hold up are lighter than in the connector. But so-called pull tests of those bolts will be conducted to verify that they can support the weight for which they are designed.

In a pull test, workers attach a hydraulic jack to the bolt that can simulate increasingly heavy weights, according to Alexander Bardow, who is overseeing the Ted Williams testing as the state's director of bridges and structures.

The workers add more weight gradually, allowing two minutes between each test. If the bolt hasn't moved when they suspend 1 1/2 to 2 times the weight the bolt is designed to handle, it passes.

``I won't feel 100 percent secure on the Ted Williams Tunnel front until we've done the calculations and the pull tests," Romney said. ``And then we'll know whether the two bolts that needed immediate actions were anomalies or whether they were representative of a systemic failure."

Sean P. Murphy of the Globe staff contributed to this report. Scott Allen can be reached at allen@globe.com; Matt Viser at maviser@globe.com.