T eliminates Green Line extension slow zones
The MBTA said Wednesday it eliminated all speed restrictions on the Green Line extension, bringing trains back to full speed across the agency’s newest part of its subway system after weeks of frustrating slow zones.
The T slowed trains to a walking pace across much of the Green Line extension branches to Union Square and Medford last month saying the gauge, or the distance between the two rails, on many parts of the tracks had become too narrow to safely operate trains at full speed. The 3-mile-per-hour speed restrictions covered more than a mile of the new track, according to the T’s dashboard, dramatically slowing commutes.
General Manager Phillip Eng said late last month he aimed to eliminate the slow zones on the Green Line extension by Oct. 13, when the branch to Union Square was scheduled to reopen after 25 days following a MassDOT highway project that required closing service.
On Wednesday, MassDOT announced that the agency completed the bridge repair work early and service to Union Square had resumed.
“In keeping with our commitment last month to expedite track repair work during the Squires Bridge project, the MBTA has removed all of the Green Line speed restrictions on both the Union Station branch and the Medford/Tufts Station branch,” Eng said in a statement. “Green Line trains today are traveling at regular line speeds on both branches. I wish to thank our riders for their patience while MassDOT completed the bridge project and we addressed the track defects discovered during an inspection last month.”
The Green Line remains closed between North Station and Government Center through Oct. 12 to accommodate the ongoing demolition of the Government Center Garage.
To eliminate the Green Line extension speed restrictions, T officials said crews had to widen the distance between the rails at hundreds of points along the tracks.
Each narrow area required fixing at least one rail tie — the rectangular, wooden support below the rails — and sometimes several, the T said, by moving one rail slightly farther from the other.
At each tie that needed fixing, crews unscrewed the four bolts that hold one of the rail plates to the tie, removed the bolts, filled the old holes with an epoxy or wooden dowels, then drilled new holes slightly farther away, the T said, and finished by screwing the bolts in again to secure the rail plate to the tie.
The T had the necessary equipment on hand, the agency said, but located more of it to be able to get the work done faster.
Eng said the T is still working on finding the root cause of the issues that forced the T to impose the speed restrictions on the Green Line extension branches.
The T has said that the Green Line extension, the first expansion of the T’s subway system since 1987 which fully opened last year, “has always been narrow,” but somehow became so narrow in recent months that it was dangerous for trains to travel at full speed, prompting more than a dozen speed restrictions along the tracks.
Track experts say it is nearly impossible for track gauge to narrow over such a short period of time.
At a MBTA board of directors meeting last month, the T’s top infrastructure official told members of the agency’s oversight board the Green Line extension — which was decades and billions of dollars in the making — “didn’t meet construction standard.”