Large section of Green Line to shut for repairs for half of December

All of the MBTA Green Line’s downtown portion and much of its branches will be closed for 15 days in December to fix a nearly 130-year-old tunnel piece, the transit agency announced.

From Dec. 8 through 22, the Green Line’s main branch will be closed from Kenmore to North Station. The E Branch will be entirely closed, and the B Branch will run from Boston College to Babcock Street, with shuttle buses running from Babcock to Back Bay. The C and D Branches will run only between their terminuses and Kenmore.

“For a planned shutdown, this is huge,” Brian Kane, the executive director of the MBTA Advisory Board, told MassLive. “That’s the entire trunk [of the Green Line], basically. That’s major.”

During the shutdown, the MBTA will replace the wooden trough inside the Green Line tunnel that holds overhead wires, also called catenary wires. The trough is original to the tunnel’s construction in the 1890s, the T said. A modern, metal trough will be installed to house the Green Line’s overhead wires, the MBTA said. While that work is ongoing, the T plans to address other goals, including signal modernization, tunnel inspections, and “station brightening work.” 

More installations are planned for the T’s Green Line Train Protection System, which updates vehicles and track equipment to avoid train collisions and speeding. Earlier this summer, some vehicles were temporarily taken out of service to update with safety equipment as part of GLTPS.

Green Line alternatives

The T recommends E Branch passengers utilize the 39 bus and B Branch passengers take the 57. Shuttle buses will run between Kenmore and Back Bay, where riders can then take the Orange Line downtown. More 39 buses will be put into service to manage the additional passengers, the MBTA said.

The MBTA will also be opening the turnstiles for riders affected. The 57 and 39 bus will be fare-free, and fares will be free at Kenmore and all surface-level stops west of Kenmore, the MBTA said.

Green Line passengers affected should budget an additional 20 minutes to their regular commute during the shutdown, the MBTA advised.

Shuttle buses will also run between the Orange Line’s Back Bay and Forest Hills stations all day Dec. 5 and Dec. 6, the MBTA said. The T will be updating stations and modernizing signals to improve service reliability.

A similar stretch of the Orange Line was already closed down for two weekends in November.

Molly Farrar is a general assignment reporter for Boston.com, focusing on education, politics, crime, and more.