Official says he erred on Big Dig

Responding to criticism from lawmakers and other officials, Transportation Secretary Jeffrey B. Mullan said he should have consulted with the governor’s office and gone public earlier. Instead, the Department of Transportation did not inform Governor Deval Patrick until Tuesday, after inspectors had already discovered corrosion affecting a few hundred of the 23,000 lights that illuminate the O’Neill and other Big Dig tunnels.

With Patrick away on an international trade mission, Mullan told the governor’s staff in a State House meeting last Friday about the corrosion problem and the temporary repairs made by his department. He said he briefed the governor by phone in London Tuesday night, telling Patrick he planned to hold a press conference the next day.

“Knowing what I know now, with the benefit of hindsight, I made an error. And I should have released this information sooner, even without the benefit of perfect information — that’s the difficult balancing test that public officials need to make,’’ Mullan said in an interview yesterday. “That won’t happen again.’’

Mullan said he prides himself on transparency and wanted to avoid creating unnecessary panic, not conceal a problem. But he now recognizes that, with the Big Dig in particular, the public should know about problems immediately, given a troubled history that includes a fatality in 2006 when a section of the tunnel ceiling collapsed.

Senator Thomas M. McGee, Senate chairman of the Legislature’s Joint Transportation Committee, called Mullan’s five-week delay in disclosing the lighting problem “poor judgment.’’

“Come out [and] say, ‘The fixture fell. We’re taking appropriate action. This could be more than an isolated incident, but we want you to know we’re right on top of it,’ instead of doing all that but not saying it,’’ said McGee, a Lynn Democrat.

No one was hurt when the eight-foot-long light fixture crashed because it fell between two lanes of traffic on the northbound side of the tunnel, which carries Interstate 93 beneath downtown Boston. Each light fixture contains two long fluorescent tubes housed in an aluminum frame; that frame is hooked by a set of 10 stainless steel clips to another aluminum frame that, in turn, is bolted to the concrete ceiling.

The state’s inspection of the light that fell showed that the rail on the aluminum frame had corroded away beneath all 10 clips. Another light fixture had corrosion beneath nine of 10 clips but remained in place, though most fixtures showed little or no corrosion. In all, about 3,000 of the 230,000 clips securing the lights were no longer holding onto anything because the aluminum rails had corroded, state officials said.

The cause of the failure remained uncertain, and state officials sent the frame from the failed fixture and other components yesterday to an independent testing lab, Massachusetts Materials Research Inc., of West Boylston, for analysis. The failing fixtures were primarily concentrated near the portals to the tunnels, fueling speculation that moisture from the outside, mixed with road salt, played a role.

Since the light fixture crashed, state engineers have been in close contact with representatives of NuArt, the California-based manufacturer of the light fixtures, but without reaching a conclusion on cause.

Mullan all but ruled out ceiling leaks — which have been a constant irritant on the project — as the culprit, because inspectors found no water pooled in the fixtures.

“We are not selecting one causation over another,’’ he said. “It could be manufacturing, it could be installation, and it could be a design defect.’’

After a concrete ceiling section in an Interstate 90 connector tunnel collapsed in July 2006, killing Milena Del Valle of Jamaica Plain, then-governor Mitt Romney ordered a “stem to stern’’ inspection of the 7 1/2-mile maze of highway tunnels, ramps, and sections that make up the $15 billion Big Dig.

Neither that review nor the subsequent annual inspections of the tunnels found problems with the lights, but the fixtures were only visually inspected. They need to be taken apart manually to show the damage, a step that will be required on future inspections, Mullan said.

State Senator Mark C. Montigny, chairman of the Senate’s Post Audit and Oversight Committee, was incredulous that the “stem to stern’’ review included only a cursory examination of the lights.

“Those buzzwords are designed to give the public confidence. In my opinion, based upon what we owe the commuter and the taxpayers . . . we should in fact do a stem-to-stern review,’’ said Montigny, a New Bedford Democrat. He criticized the “residue and the stench of Big Dig culture’’ of cost overruns and design or construction problems that continue to afflict the public, a quarter-century after the project was planned and about a decade after it was largely finished.

Montigny said he admires Mullan, whom Patrick appointed in 2009, but that he erred in not disclosing this problem sooner.

Representative William M. Straus, the House chairman on the Joint Transportation Committee, agreed, calling it “a judgment decision [that Mullan] probably would like to have back.’’ The Mattapoisett Democrat said the state should conduct a “failure analysis’’ of all that could go wrong with the nonstructural components to the tunnels, given problems that have included guardrails whose flawed design make them a hazard to motorists involved in vehicle crashes. The rails, designed to protect workers, are blamed for seven deaths between 2005 and 2008.

“No one wants us to be reacting again,’’ Straus said. “I think there’s a review that has to occur beyond the light fixtures.’’

The Patrick administration directed questions yesterday to Mullan and the Department of Transportation. With Patrick scheduled to return night from London, a spokesman did not address whether the governor would have wanted to know earlier about the tunnel problems.

“Secretary Mullan briefed Governor Patrick about this issue on Tuesday evening, and outlined MassDOT’s efforts to address this issue in a timely manner that ensures the safety of the public,’’ Patrick spokesman Alex Goldstein said by e-mail. “The governor directed Secretary Mullan to notify the public about this issue, and they did so the following day.’’

NuArt did not return multiple calls from the Globe seeking comment yesterday or Wednesday. The state on Wednesday sent a letter to the company detailing what it called “two serious problems with your tunnel lighting’’ fixtures — the loss of paint that has exposed the aluminum to the elements, and the specific corrosion where the aluminum comes in contact with the steel clips.

Eric Moskowitz can be reached at emoskowitz@globe.com. Sean P. Murphy can be reached at smurphy@globe.com.