Saying he has serious doubts about the safety of more than 1,100 hangers that hold up heavy concrete ceiling panels in the closed Interstate 90 connector tunnel, Governor Mitt Romney outlined an ambitious plan yesterday to reinforce or remove each of the steel rods.
He said the work would take two months or more, but that some heavily traveled ramps could reopen over the next two weeks.
State inspectors have concluded that 1,146 hangers suspended from the connector tunnel roof by bolts and epoxy are unreliable, including 225 hangers held in place with at least one bolt that is no longer flush with the roof, Romney said. Rather than remove most of the supports, he said, a European company will add a second support beside each suspect one.
The governor said the concrete panels will not be replaced in the 200-foot section where a ceiling collapse last week killed one woman, suggesting that they were unnecessary in the first place.
``Now we consider all of the bolts [held up by epoxy] . . . to be of concern," said Romney at a State House press conference that sometimes seemed like an engineering class, complete with the governor drawing ceiling bolts and hangers on an easel. ``We cannot have a high degree of confidence in any of them. . . . We are going to be creating redundancy for every single one."
He said inspections of connector ceiling support identified another 308 ``items of concern."
Romney also promised that inspectors would soon begin pull tests of some of the 12,040 hangers held up by epoxy and bolts in the Ted Williams Tunnel, though he expressed optimism that the ceiling is sturdier than that in the I-90 connector. He also promised daily visual inspections of the 60 hangers suspended by epoxy and bolts in the Thomas P. O'Neill Jr. Tunnel, until state officials can permanently reinforce or remove them.
Romney said state transportation officials haven't begun to estimate the cost of the repair work, but he said he made a pitch for federal assistance in a meeting yesterday with Senators Edward M. Kennedy and John F. Kerry and US Representative Michael E. Capuano.
``I'd be embarrassed if I didn't always ask for federal money whenever I got the chance," Romney quipped, saying he had asked for help in paying for a comprehensive safety review of the Big Dig, for which the state has allocated $20 million.
Romney said he had asked Lieutenant Governor Kerry Healey to investigate the cost of the disruption on Massachusetts businesses. He said the cost of the tunnel accident must include everything from police overtime, estimated at $65,000 a day for Boston alone, to the lost tourism from people concerned about getting to and from the airport.
Designers of the $14.6 billion Big Dig project commonly included a drop ceiling in the tunnels to create an upper chamber away from the traffic where emergency workers could pump in fresh air quickly in the event of an emergency, such as a fire. In most cases, Romney said, the drop ceiling's hangers were bolted into a steel beam in the tunnel roof.
However, in dozens of locations, the steel attachment was not directly over the spot where workers needed to put the drop ceiling's frame, so they would drill a hole into the concrete roof, insert a bolt, and then glue it into place with a powerful epoxy. ``In a number of cases, you'll see an epoxy bolt right here and a steel connector is only 2 or 3 inches away," Romney said.
He said there were no embedded steel connectors in the roof of the 200-foot-long section where the ceiling collapsed, forcing crews to rely entirely on the bolt-and-epoxy system. As a result, that area was far more vulnerable than other tunnel ceilings when the epoxy began to prematurely age and fail, Romney said. It appears that 16 epoxy-and-bolt hangers let go in the accident that killed Milena Del Valle, he said.
To fix the problems, Romney said the Executive Office of Transportation has brought in Hilti, a leading maker of industrial adhesives based in Lichtenstein and with US offices in Oklahoma.
He said the company was to begin testing one of its products, called an undercut anchor bolt, last night on concrete similar to the roof of the I-90 connector tunnel. The anchor bolt, a 10-inch-long piece of steel, is inserted into concrete, and then a special attachment at the tip of the bolt expands to dig into the concrete and hold the bolt in place without using epoxy. The hanger for the drop ceiling would then be suspended from the bolt.
Where possible, Romney said, workers in the I-90 connector will add a second hanger beside suspect ones by attaching it to the embedded steel beam that previously went unused. ``That's the preferred system," Romney said. However, where that isn't practical, Romney said, crews would attach the extra support hangers to the undercut bolts from Hilti.
Scott Allen can be reached at email@example.com.