The opening of the first Green Line Extension branch has been delayed — again

"I have a real high level of confidence that this will be the last delay."

The Green Line Extension viaduct where the Medford and Union Square branches diverge. MassDOT

MBTA officials had initially envisioned beginning passenger service on the Green Line Extension’s shorter branch to Union Square this month. Then, in June, they announced the branch’s opening would be delayed until December.

Now, that ribbon cutting is going to have to wait another three months — and the planned May 2022 opening date of the longer Medford branch may be pushed back as well.

MBTA General Manager Steve Poftak announced Thursday afternoon that the opening of the Union Square branch would be postponed until March, primarily citing unexpected issues with a power substation built for the project.

“That’s unfortunate,” Poftak tolder reporters during a conference call. “We really were looking forward to delivering this project in December. But we’ve faced a variety of challenges that have forced us to push the schedule out.”


Officials had cited supply chain issues exacerbated by the COVID-19 pandemic for the first delay announced in June.

Poftak said the new delay was primarily due to productivity challenges setting up an electric substation — located near an elevated viaduct near the Cambridge-Somerville border where the two GLX branches diverge — that will provide power to the Green Line trolleys on the one-stop Union Square branch.

According to Poftak, crews were constrained by the size of the station, making the process “more challenging than the original schedule had envisioned.”

A power substation along the Green Line Extension. – MBTA

“There’s only so many people who can fit inside that space and do productive, technically demanding work,” Poftak said, noting that it was just one of a “variety of issues” the project had faced, including testing and commissioning.

Poftak said that there are two similarly sized power stations along the longer, five-stop branch through Somerville to Medford, and said that crews are hoping to apply the newly learned lessons to their work on the so-called “Branch 2.”

However, he suggested that the Medford branch’s opening — already delayed from this December until May 2022 — would likely be delayed as well.

“It is one of the challenges we are facing, and it is one of the areas that we are concentrating on as one of the critical path items,” Poftak said. “If we’re not more productive and more efficient in building out these next two traction power substations, it is going to impact the schedule.”

Inside the power substation. – MBTA

Poftak noted that the MBTA has been in close conversations with GLX Constructors — the group of companies contracted to build the $2.3 billion project — about the impacts on the Medford branch and would make an announcement when they had more confidence in the schedule.


“I have not abandoned all hope on that,” he said.

While he acknowledged the news was “disappointing,” Poftak expressed confidence that Thursday would be the last time he would have to make such an announcement, at least when it came to the Union Square branch.

“I have a real high level of confidence that this will be the last delay, sort of leaving open that we are still working on Branch 2,” Poftak told reporters.

“It was my hope that the announcement in June was our final announcement related to schedule,” he said. “Obviously, that’s not the case. We have spent an awful lot of time — both internally at the T and with GLXC — to make sure that we can hit this March date.”

The delay also affects the opening of the revamped Lechmere station, which has been closed since May 2020 and will reopen with the rest of the Union Square branch, according to Poftak.

Poftak also said he was unsure what the impact might be on the two-mile extension of the Somerville community path being built along the Medford branch to Cambridge Crossing. In an email, MBTA spokesman Joe Pesaturo said that the T cannot commit to having the path available for use before trolley service starts. 


“This path currently serves as a critical access point to continue the construction work on GLX,” Pesaturo told Boston.com. “As such, work to complete the path will continue after rail service begins.”

Poftak noted that the delay announced Thursday will result in additional costs for the project, which has been on track to come in under budget and has a $300 million built-in contingency fund. Even with the additional costs, Poftak said he expects the project to remain under budget.

He also said that the MBTA is planning to put forward a revised GLX contract next month to officially return tens of millions of dollars that Cambridge and Somerville have contributed to the project. The two cities had made an “unprecedented” $75 million commitment to the project in 2016, around $30 million of which has already been paid, Poftak said.

“We’re confident at this point that the project does not need that money,” he said. “We’re appreciative that the communities were willing to step up when this project was very much in doubt, and we think it’s appropriate at this stage of the project to return the money.”

However, that announcement — which Poftak had signaled was likely in June — was overshadowed by the news of the delay Thursday, which comes after local officials and residents waited decades for state officials to permit the project.

“Excuse me while I go break every object I can find,” Somerville Mayor Joe Curtatone tweeted Thursday afternoon. “I understand these things happen, but I don’t have to like it.”


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