The Massachusetts Bay Transportation Authority is “aiming” to reopen train service on the Green and Orange lines in downtown Boston Monday morning, officials said Saturday, after service in the area was abruptly halted Thursday night due to a deteriorating support column beneath the Government Center Garage.
The MBTA will resume regular operation on the Green and Orange lines Monday “if deemed safe by internal and third party engineers and safety experts,” the agency said in a statement.
On Sunday, the Orange Line will remain closed between Back Bay and North stations, and shuttle buses will continue to run in place of Green Line service between Copley and Government Center stations, the MBTA said in a statement.
The support column, one of seven that holds up the Government Center Garage and passes through the MBTA’s subterranean infrastructure near Haymarket Station, has deteriorated due to years of water damage, officials said.
The garage is being demolished to make way for a multibillion-dollar mixed-use real estate development called Bulfinch Crossing. HYM Investment Group, the lead developer on the garage project, said Friday the deteriorated column is “unrelated” to the garage demolition work.
On Saturday, the T said it is working with HYM to reinforce the structures.
“Repair work continues to be underway and the MBTA will continue to support HYM’s contractors by delivering workers and materials to the site,” the T said in the statement. “Structural engineers and safety experts are also on scene monitoring the site, performing intensive examinations and assessments of the infrastructure above and below the surface at Haymarket. These teams are and will be ready to assess their work to ensure the safety of all infrastructure before allowing MBTA service to resume.”
The closures on the T came as riders are already faced with reduced weekday service on the Orange, Blue, and Red lines because of a dispatcher shortage identified by federal officials.
The state Department of Transportation tried to help ease the burden on travelers by keeping the Sumner Tunnel open this weekend. MassDOT said Friday that it had suspended work scheduled to begin later that night and end early Monday morning, part of an extensive restoration project on the 88-year-old tunnel.
As part of the project’s first phase, the tunnel has been closed to travelers every weekend since June 10 and will continue to be closed on weekends into February of next year, except for holidays.
“The decision to suspend planned work was made to minimize any additional travel impacts created by the suspension of regular MBTA Orange and Green Line service in the area of Haymarket Station,” the statement said.
The project includes restoring the 88-year-old tunnel’s overhead arch and ceiling; painting the interior tunnel walls; installing new lights, utility conduits, and cables; and building a new roadway surface.
“While the Sumner Tunnel is in need of repairs, it remains safe for traffic to use,” MassDOT said in the statement. “Recent instances involving a construction site near the MBTA’s Haymarket Station have had no impact on the Sumner Tunnel’s structural integrity,” MassDOT said in its statement.”
Material from previous Globe stories was used in this report.
Nick Stoico can be reached at email@example.com. Follow him on Twitter @NickStoico.