Boston's $2.3-billion Green Line Extension Faces More Problems

Defective rails need repairs less than a year after the project opened

The Medford Branch of the Green Line Extension opened on Dec. 12, 2022

The MBTA is reviewing a plan submitted by GLX Constructors to repair defective tracks on the Green Line Extension, less than a year it opened.

Photo courtesy of the MBTA

The joint venture that built the total 4.4-mile Green Line Extension from Cambridge into both Somerville and Medford is facing the task of repairing miles of defective rails in a major setback for the $2.3-billion trolley line, called GLX, which opened less than a year ago.

The Massachusetts Bay Transportation Authority (MBTA) says it is reviewing a plan submitted by GLX Constructors to repair the defective tracks, which were too narrow when installed, forcing trains to slow down to walking speed along large stretches.

GLX Constructors, consisting of Fluor Enterprises Inc., the Middlesex Corp., Herzog Contracting Corp. and Balfour Beatty, will be required to pick up the tab for the repairs, which will involve widening extensive sections of the rails, Phillip Eng, the general manager of the system known as the T, told reporters at a press conference.

Neither GLX Constructors nor the MBTA responded to requests for comment.

At the center of the controversy are faulty prefabricated plaited rail ties. Each consists of a wooden tie with steel plates on either end holding the rails in place.

The plaited rail ties were manufactured based on specifications that were too narrow, Eng stated at the press conference, according to a story in CommonWealth Magazine.

T officials first acknowledged the issue with the too narrow rails a few weeks ago, only to acknowledge last week that the problem is much more extensive than they first thought.

As much as half of the rail ties on the GLX’s Somerville branch, which is 1 mile, will need to be widened. That involves taking off the steel plates, adjusting them and then putting them back on the rail ties. The same procedure will need to be done for as much as 80% of the Medford/Tufts branch, which is 3.4 miles.

Still, many basic questions have yet to be answered on the looming repair work, including how long it would take, what it would cost, and what the impact would be on commuters who use the GLX.

Meanwhile, Eng, who took over as head of the MBTA last spring, contends a review by the agency found that executives at GLX Constructors and other contractors may have known about the defects as far back April 2021. An inspection by Terracon found the track to be too narrow at points inside the Medford rail yard, according to CommonWealth.

Another review last November, shortly before the opening of the second and last branch of GLX, uncovered dozens of spots on the tracks that were too narrow.

For its part, GLX Constructors has already taken the project’s designer, STV, to court, alleging a series of errors, ranging from faulty retaining walls to defective noise barriers, though issues with the design of the tracks were not among the complaints.

GLX Constructors is seeking $35 million from STV.

Scott Van Voorhis writes regularly for ENR about risk management, insurance, and the Canadian engineering, construction and infrastructure sectors. He launched his own freelance writing business in 2008 after nearly two decades as a reporter and business columnist for the Boston Herald, Boston Business Journal and The Eagle-Tribune.