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MBTA delays Green Line extension project again

Workers on the Green Line Extension project last year.Stuart Cahill

Passenger service on the long-awaited Green Line extension project has been delayed . . . again.

Citing slower than anticipated progress in getting an electrical substation fully up and running, MBTA General Manager Steve Poftak said Thursday that the branch adding a single new stop in Somerville’s Union Square — branch one — will now open in March 2022, three months later than its current estimated delivery date.

The other branch consisting of six new stops running between East Cambridge and Medford — branch two — is still tentatively scheduled to open in May 2022, consistent with the five-month delay announced earlier this year.


“I have not abandoned all hope on that,” Poftak said about branch two opening to passengers in May. “I have a real high level of confidence this will be the last delay, leaving open we are still working on branch two.”

It has taken longer than expected to complete the new substation that will provide power to branch one due, in part, to the substation’s size. Fewer people than anticipated can concurrently work on the substation, slowing productivity, Poftak said.

There are two new substations needed for branch two.

“We learned a lot of lessons from our work on branch one that we are in the process of transferring to branch two,” Poftak said.

Thursday’s announced delay is the latest in a string of setbacks on the $2.3 billion project that has been discussed for decades.

The state committed to the Green Line extension as a result of a lawsuit citing the Big Dig’s environmental impacts on surrounding communities. Construction on the 4.7-mile project began in 2018 with the goal of beginning passenger service the at seven new stations to Medford and Somerville’s Union Square by December 2021. In June, the MBTA pushed back the delivery date on the Medford branch from the end of this year to May 2022, citing supply chain impacts from the COVID-19 pandemic.


Poftak said he does not expect the most recent delay to take the project outside its budget and contingency funds.

The Massachusetts Bay Transportation Authority plans to ask its new board of directors at the panel’s November meeting to formally approve a return of funds associated with the project to Somerville and Cambridge, Poftak said, something the agency had previously said it would do. Somerville had originally pledged $50 million and Cambridge $25 million.

The new board of directors plans to have its first meeting on October 27 and meet monthly going forward.

Earlier this month, Poftak said he was holding an internal meeting at the MBTA to discuss how to speed up implementation of an anti-collision technology on the Green Line, following a crash between two trains in July. The National Transportation Safety Board first urged the MBTA to put the tech on the Green Line in 2009 following two similar crashes. The MBTA plans to have the tech on the entire Green Line, including the new branches, by 2024.

On Thursday, Poftak said coordination between departments is ongoing to try to see if that deadline can be moved up.

“We still have to do some internal work to the extent we can execute on those strategies,” he said.

Taylor Dolven can be reached at taylor.dolven@globe.com. Follow her @taydolven.