The MBTA's new Orange Line trains, which debuted this summer, have been taken out of service indefinitely while engineers investigate an "uncommon noise" coming from the underside of the new trains.
"With safety as a top priority and out of an abundance of caution, the decision was made to temporarily remove the new cars from service to investigate the issue, any potential impacts, and deploy a fix, if needed," wrote Battison in an email message Monday morning. "We anticipate the issue to be resolved soon with the cars back in service following this investigation, which is currently taking place."
At a Wednesday press conference, MBTA General Manager Steve Poftak added that, after some testing, MTBA engineers have pinpointed the source of the noise as a wear pad at the location where the trains' wheel trucks are attached to the body of each car.
Poftak stressed that the MBTA wants to address the issue now, before additional new trains are manufactured and delivered. Under the Orange Line's new vehicle procurement program, the MBTA expects to take delivery of 152 new Orange Line cars before the end of 2021.
"I've repeatedly emphasized to our vehicle engineering team that safety and a durable long life for these cars is a top priority," said Poftak. "So by catching this issue now we're able to fix it and not have it occur on the remaining cars... we want to be able to fix this problem now at the earliest stages."
Poftak declined to estimate when the new cars could be back in service.
According to newtrains.today, a website that monitors data from the MBTA's real-time vehicle location service, the new Orange Line vehicles haven't been in service since November 18, the same day that one of the new trains had gone off the rails in the Orange Line's maintenance and storage facility in Medford:
Since then, though, the rollout of new trains has stalled, with no new trains entering service in October or November. In order to meet the agency's goal of replacing all of the Orange Line's trains by 2022, new 6-car trains would need to enter service roughly every month for the next 24 months.