A key Big Dig ramp may open next week

A key Big Dig ramp linking the westbound Ted Williams Tunnel and Interstate 93 is set to open as soon as next week, unclogging downtown and South Boston streets where thousands of vehicles are detoured, state officials said yesterday.

The opening would restore a major link between the Massachusetts Turnpike, Logan International Airport, and I-93 north and south. It would leave only the westbound Interstate 90 connector tunnel still completely closed, as a result of deficiencies found after the fatal ceiling collapse July 10 in the connector.

A series of extensive repairs on what is known as Ramp D -- including replacing epoxy anchor bolts, installing ceiling brackets, and adding diagonal hangars to keep the suspended ceilings from swaying in an earthquake -- are 99 percent complete, a spokesman for the state's Executive Office of Transportation said yesterday.

The ramp can be reopened once the tunnel's ventilation system is tested Sunday and federal officials approve the repairs, the spokesman said. Now, westbound traffic in the Ted Williams must exit in South Boston and take a circuitous detour to get to I-93.

The announcement was made just days before an election in which the candidates for governor have sparred over the Big Dig and accusations of mismanagement.

Jon Carlisle, spokesman for the Executive Office of Transportation, said there was no connection between the Ramp D opening and the election. "We're getting it done as quickly and as safely as possible," he said yesterday.

The state has been working since the fatal collapse to bring the Big Dig back to normal. But officials found many more problems than expected after Romney assumed oversight of the tunnel network from the Turnpike Authority.

Two hundred ceiling bolts had to be replaced in Ramp D alone, along with 400 to 600 brackets and about 200 diagonal hangers, state officials said. One reason Ramp D could not reopen sooner is because there was no traffic lane that did not have major problems in its ceiling.

On Sept. 1, the state reopened a single lane in the eastbound I-90 connector tunnel, using aluminum shoring towers to hold up flawed ceilings in adjacent lanes. A ramp in South Boston leading into the eastbound Ted Williams Tunnel opened in August.

State studies show that the opening of those links, combined with opening Ramp D, could cut traffic congestion around the Big Dig by 40 percent.

Starting tonight, however, the open lane in the eastbound I-90 tunnel will be closing from 8 p.m. to 5 a.m. for the next two to three weeks for additional repairs to the ceiling, officials said. The tunnel will also be closed from 8 p.m. to 7 a.m. Friday and Saturday.

The detour will take traffic back to the Government Center exit to reach the Callahan Tunnel to Logan, affecting travel in the Financial District and downtown.

Mac Daniel can be reached at mdaniel@globe.com.