fb-pixel

Here’s why the T says Red Line repairs are taking so long

Workers assessed the tracks and a damaged structure on the Red Line at JFK/UMass.
Workers assessed the tracks and a damaged structure on the Red Line at JFK/UMass. (Craig F. Walker/Globe Staff)

It’s been more than 24 hours since a Red Line train derailed just as the morning commute was beginning, and service on the line is still disrupted for many riders.

What’s taking so long?

The MBTA offered an explanation in a series of tweets Wednesday, saying that when the train derailed, it struck and damaged sheds — called “bungalows” — that contain equipment that runs the T’s signal system.

Signals are a critical part of T infrastructure, as anyone who has ever been delayed by “signal problems” knows. They’re a sprawling network of sensors and cables that determine when trains can proceed — and when they cannot. On the Red and Orange lines, the system works by blocking off portions of track, allowing only one train at a time on each portion. The system also detects any obstructions or other issues with the tracks.

Advertisement



The equipment damaged in Tuesday’s derailment specifically controls the systems at the point where the Red Line splits into the Ashmont and Braintree branches, T spokesman Joe Pesaturo told the Globe on Wednesday.

“Without the signal system, trains must be given permission from our Operations Control Center to move from one station to the next, one train at a time. This also means we need people along the tracks to physically set the routes to direct trains,” T officials wrote in a tweet.

The damage to the signal equipment is also the reason the countdown clocks have been turned off along the entire Red Line.

Signal bungalows were damaged during the Red Line train derailment at JFK/UMass Station on Tuesday.
Signal bungalows were damaged during the Red Line train derailment at JFK/UMass Station on Tuesday. (Craig F. Walker/Globe Staff)

If that sounds like a lot of damage, it is. Photos released by MassDOT on Wednesday showed twisted metal and crushed equipment at the site of the derailment. The T said it will need to replace equipment in the bungalows, including signals and cables, and rebuild them. The track itself will also need to be repaired. Workers are currently assessing the full extent of the damage, Pesaturo said.

Advertisement



See the T’s full tweet thread:


Adam Vaccaro of the Globe staff contributed. Christina Prignano can be reached at christina.prignano@globe.com. Follow her on Twitter @cprignano.