BOSTON — Tracks were built out of gauge on the Massachusetts Bay Transportation Authority’s Green Line extension, meaning the 4.7-mile, $2.3 billion project faces significant rebuilding less than a year after it opened.
MBTA CEO Phillip Eng revealed the problem at a press conference today (Thursday, Oct. 19). An MBTA spokesman said 80% of the extension’s branch to Medford, and 50% of the branch to Union Square in Somerville, would have to be regauged, although Eng told the Boston Globe, “it’s the whole length of the project that I believe needs to be regauged to be back within the contract requirement.”
Eng told the Globe in an interview that said some people within the agency have known the distance between the rails was too narrow on large portions of the extension’s two branches even before the lines opened last December, but no one addressed the issue, no one informed him until last month, and he did not know the extent of the problem until he reviewed project documents.
“I wish I had known earlier,” Eng told the Globe. “Because then I think we would have tackled this.”
The MBTA is working with the project’s contractor on correcting the problem, which will involve repositioning tie plates by unscrewing bolts from the plates on one rail, filllng the existing holes in crossties, then drilling new holes and bolting in the plates at the correct gauge. The process could take weeks, Eng indicated.
The Green Line, like other MBTA transit lines, is standard gauge, or 4 feet, 8½ inches. WFXT-TV reports the construction contract required a track gauge within a sixteenth of an inch of that standard in either direction, while the threshold for slow orders is anything narrower than 4 feet, 8 1/8 inches. Currently, the entire extension is above the slow-order threshold, but about a half-mile on the Union Square branch and 2.7 miles on the Medford branch is narrower than the 4 feet, 8 7/16 inches permissible under the contract.
The station reports that the contractor, GLX Constructors, is a joint venture including Fluor Enterprises, the Middlesex Corp.; Herzog Contracting Corp.; and Balfour Beatty Infrastructure Inc. Eng said at Thursday’s press conference that the contractor should cover the cost of the repairs, although that cost has not yet been determined; an MBTA representative said the agency will be holding discussions with the builders as part of closing out their contract.
Tie plates were improperly positioned on the ties during construction of the Green Line track, a problem detected in inspections at least as early as April 2021, but not addressed. The Globe reports more than 24,000 feet of track gauge was outside of construction specifications on the Medford branch prior to the line’s opening, according to internal emails obtained by the newspaper. The worst problems were fixed before that line opened Dec. 12, 2022, but other problems became public last month when slow orders were enacted at 29 locations that limited the Green Line’s light rail equipment to speeds as low as 3 mph. Those spots have since been repaired.
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