Two of the four tunnels under Boston Harbor are in desperate need of repair Massachusetts Gov. Mitt Romney concluded yesterday after his “stem-to-stern” inspection of the entire Big Dig project which uncovered hundreds of structural defects.
Yesterday’s findings focused on the older Sumner and Callahan tunnels, and the safety audit committee — created after the July 10 ceiling collapse in the Interstate 90 Connector Tunnel that killed a driver — has yet to report on of the rest of the Boston’s underground tunnels.
“My reaction when I saw that was ‘holy cow,'” Romney said. “It’s pretty frightening.”
Because of the tunnels’ old age, much of the concrete is now spalling — or chipping — off of the steel rebar that supports it, Romney said.
In the Sumner tunnel — completed in 1934 — inspectors found 30 percent of the concrete spalling from the rebar.
For now, inspectors are combing both tunnels and tapping the interiors with hammers to take off any concrete before it falls onto cars. To drive his point home, Romney held a 5-pound chunk of concrete they had chipped off from the tunnel.
“The Sumner condition is such that a long-term structural repair is going to have to be done,” he said. “This is not something that is just going to be repaired in the evening. This is a major project to realign and repair the inside of that tunnel. It’s going to be an inconvenience.”
Yet Romney was quick to caution that repairs would not begin until other tunnels reopen.
“We surely want to get those other tunnels open before we start dealing with massive repair work in the Sumner tunnel, which of course would require lane closures,” Romney said. “So this will not begin immediately.”
He added that some sections of the closed Interstate 90 Connecter Tunnel could open as early as October, while others need more time.
Romney said Phase I of the safety review, which includes reviewing safety across the “Big Dig” project, should be done by November. Phase II, which will seek to correct problems found, will continue into next year and beyond Romney’s term in office.
But the governor refused to estimate the price tag of the additional repairs, saying the cost will depend on the extent of the damage inspectors find..
During the 1990s, the Massachusetts Turnpike Authority hired Parsons Brinkerhoff to retrofit the Callahan and Sumner tunnels. The firm did not respond to a Daily Free Press email.
Workers install new tiling and replace an old concrete ceiling that separated the roadway from the upper ventilation shaft with newer, lighter paneling, Romney said. Unlike the old ceiling, the panels were suspended by steel hangers attached to the top of the tunnel similar to those used in the Interstate 90 tunnels, he added.
The Callahan tunnel is damaged in areas different from the Sumner Tunnel, and inspectors found some ceiling hanger bolts weak or missing.
“There are a number of bolts where there has been slippage, even though the spalling in the Callahan has not been as bad as in the Sumner,” he said. “There have been some 418 of these now since the tragic accident this summer that have been repaired or remediated.”
Romney added that the audit found steel braces, which were installed in the Sumner tunnel to support the ceiling during an earthquake, were missing in the Callahan tunnel.
“Our concern is that the seismic qualities of the Callahan tunnel are not up to snuff,” Romney said.
Romney speculated on why the renovations did not correct these problems, but avoided placing any blame for the review’s findings.
“The objective of the stem-to-stern audit is to assess the structure and safety in sufficient detail as to express a reliable independent opinion,” he said. “We’re not looking at who’s responsible for the past, we’re not looking at maintenance concerns; we’re just looking at safety of the entire system for the traveling public.”
While the state is seeking to recover the cost of repairs from the contractors who worked on the newer Big Dig project, Romney said he expects taxpayers will have to pay to repair the older tunnels because the original builders were not at fault.
“It’ll be on our nickel,” Romney said. “I’m afraid in the case of the Sumner, you have a tunnel that was built over 70 years ago. It’s very natural for concrete to come out . . . over time. You’ll see it throughout the highway system.”
Drivers should still feel safer knowing these problems were addressed, Romney said.
“It is the assessment of the people who are professionals in this area that there is no undue risk at this stage to public safety,” he said. “An inspection system with immediate maintenance can provide for safety.”
Safety Review Board Director Stephen Pritchard said the board was surprised by its findings.
“We didn’t have any indication that there would be this kind of deterioration,” Pritchard said, adding that there is still work to be done on other tunnels.
“We’ve got a lot of parallel activity going on for the Big Dig,” Pritchard said.