Crack on Big Dig bridge limits trucks
Detour set for Leverett Connector
Federal highway engineers have asked the state to restrict heavy trucks from using a portion of a Big Dig connector bridge where inspectors found a crack on a concrete support earlier this year, officials said yesterday.
State officials insist the area where the crack was found, on the Leverett Connector Bridge that links the Tobin Bridge with Storrow Drive and Interstate 93, remains safe. But the latest findings show yet another concern about the $15 billion road project.
Engineers discovered the crack during a just-completed "stem-to-stern" review of the roadway initiated following the July 2006 ceiling collapse that killed Milena Del Valle.
"We can blame the lack of oversight over the Big Dig as one of the causes, and we've inherited that and we're dealing with that now," said Mac Daniel, spokesman for the Massachusetts Turnpike Authority.
News of the detour for trucks over 40 tons was announced after the close of business yesterday, and federal officials could not be reached for comment.
The Federal Highway Administration sent a letter to the state transportation department dated Aug. 21, but state officials said they did not receive it until yesterday afternoon and began restrictions on the road immediately. They could not explain the delay.
Lucy Garliauskas, division administrator for the Federal Highway Administration in Boston, wrote that "the prudent course of action is to immediately restrict the bridge to Legal Loads [those under 40 tons] only until the bridge is strengthened."
The crack was discussed at the Turnpike Authority board's August meeting, when the "stem-to-stern" review was officially completed. Klark Jessen, a spokesman for state Transportation Secretary Bernard Cohen, said in an e-mail that engineers have been monitoring the crack since April and that its size has not changed. He called the federal recommendation "ultra-conservative" but said the state agrees with it.
The restriction will affect trucks coming from the Tobin Bridge, traveling southbound either to Leverett Circle and Storrow Drive or to the Zakim Bridge. The connector is actually an elevated roadway. The damaged portion is directly above the Boston Sand & Gravel Co., Daniel said.
Jessen said crews will begin work on the bridge soon and complete it no later than Nov. 1.
The state has more than $400 million set aside for unforeseen Big Dig repairs as part of a January settlement with contractors. Daniel said that money may be used to repair the crack, but it has not yet been determined.
Daniel called the crack "minor" but could not say exactly how large it is.
"The bridge is completely safe," he said. "We wouldn't in any way, shape, or form be allowing traffic to go over the roadway if we thought it was unsafe."
He said the restriction will affect only the heaviest 18-wheel trucks using the connector. Traffic planners are working on an alternate route that will be posted sometime today, he said.
"I think there were far greater concerns pulled out in the stem-to-stern report than this," Daniel said.
The report also listed issues with ongoing leaks and deterioration in the Callahan and Sumner tunnels.
Mary Connaughton, a Turnpike Authority board member, said the latest problem is a concern because last month's report did not indicate any immediate measures would be necessary.
"After all the billions of dollars spent on this project, it's a shame that we're at the stage where we actually have to close a portion of it off to traffic," she said.
Staff writer Martin Finucane contributed to this report.
Noah Bierman can be reached at nbierman@globe.com. 