T delays Green Line extension a second time
Union Sq. branch now set to open 3 months later in March
THE MBTA is once again delaying the initial opening of the Green Line extension into Somerville, this time because cramped quarters in a newly built facility for delivering electricity to the subway line is making it difficult to get enough workers inside to finish the job on time.
The Green Line extension has two branches – one to Union Square in Somerville and the other to Medford. In June, the MBTA said the opening of the Union Square branch was being pushed back from October to December. On Thursday, MBTA General Manager Steve Poftak said the opening of the Union Square branch is now scheduled for March.
The scheduled opening of the Medford branch, which in June was pushed back from December to May, has not changed, but Poftak indicated it might. “I have not abandoned all hope on that,” he said, while noting there are two of the cramped electricity substations on the line to Medford.
“I have a real high level of confidence that this will be the last delay,” Poftak said.

Inside the electricity substation on the Union Square branch of the Green Line extension. (Photo courtesy of MBTA)
The general manager said the T’s private construction team is taking lessons learned from the substation work on the Union Square branch and applying them to work on the substations on the Medford branch. Poftak acknowledged, however, that the biggest challenge is that the space inside the facility is finite and only so many workers can fit inside at a time.
Poftak said the T remains on budget with the $2.3 billion project and, as previously reported, plans to return all of the money Somerville and Cambridge contributed to the project when its future was in doubt. Somerville pledged $50 million and Cambridge $25 million, but they contributed only $30 milliion and $15 million, respectively.
Poftak said the return of the money to the two municipalities will be set in motion at the new MBTA oversight board’s meeting in November.The construction delays on the Green Line extension represent a setback for the T, but they don’t undermine what many consider a major success story for the transit authority. In its early stages, the Green Line extension ballooned in cost from $2 billion to $3 billion, creating the impression that the T couldn’t manage a project of that scale and size. State transportation officials redesigned the project to eliminate roughly $1 billion in costs and hired a management team led by John Dalton whose sole job was the getting the job done.