Why did the MBTA shut down the Green Line in December 2025?

The Green Line experienced a two-week shutdown to allow crews to replace 130-year-old wooden troughs in the tunnels with modern safety equipment.

What were the wooden troughs in the Green Line tunnels used for?

The wooden troughs served as a barrier between the electrified train wires and the tunnel ceilings, dating back to the late 1890s.

When will the MBTA's Green Line reopen after the major upgrade?

The Green Line was scheduled to reopen on the morning of Tuesday, December 23, 2025, after the completion of the trough replacement project.

Home / Business and Economy / MBTA Replaces Century-Old Wooden Tunnel Supports

MBTA Replaces Century-Old Wooden Tunnel Supports

22 Dec, 2025

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Summary

Wooden troughs in Green Line tunnels dated back to the 1890s.
Replacement involved a two-week shutdown of Downtown Boston lines.
Modern metal troughs will last well over a century.

MBTA Replaces Century-Old Wooden Tunnel Supports

Wooden troughs in the MBTA's Green Line tunnels, originally installed in the late 1890s, have been replaced with modern metal versions. These original components, which acted as crucial barriers for the electrified train wires, had degraded over time and presented a fire hazard. Federal and state officials had mandated their replacement, leading to a comprehensive upgrade project.

The replacement effort required a significant two-week shutdown of the Green Line's four branches across Downtown Boston, concluding on December 22, 2025. During this period, maintenance crews worked around the clock to replace approximately 13,000 feet of the aging wooden troughs. This intensive work also allowed for other crucial projects, such as installing the new Green Line Train Protection System and reinforcing tunnel ceilings with new steel beams at Boylston station.

This "bite the bullet" strategy, involving extended service disruptions, was deemed the least disruptive method for completing the necessary rehabilitation. The MBTA acknowledged the public's patience, understanding the impact of the shutdown on the roughly 50,000 daily riders. The new troughs are expected to significantly outlast their predecessors, ensuring enhanced safety and longevity for the transit system.