One of the T’s new Orange Line trains was back on the rails this morning to carry passengers for the first time since a March 16 incident in which one of the new trains derailed near Wellington station.

“One of the new Orange Line trains was returned to service this morning,” MBTA spokesperson Joe Pesaturo told Streetsblog in an email on Friday morning.

Pesaturo added that the train had been “accepted by the T’s Safety Department and the Department of Public Utilities” under a corrective action plan to address  manufacturing issues that may have played a role in the March derailment.

In the last public update on the incident, during a June MBTA board meeting, Deputy General Manager Jeffrey Gonneville reported that older track equipment that was being replaced in the vicinity deserved partial blame for the derailment.

But an investigation into the incident also revealed issues with the new trains’ “side bearer pads,” a component that regulates rotational forces between the trains’ cabins and their wheel truck assemblies when the trains go through curves (see diagram at left).

“All parties agree, both the MBTA, our engineering consultant, and (the trains’ manufacturer) CRRC, that the rotational force of the truck itself on the car is outside of the design limits, and we are all currently working on strategies to reintroduce these cars back into revenue service,” Gonneville told board members in June.

As of Friday morning, only one new trainset had returned to service on the Orange Line; a new trainset that had started running on the Red Line this winter hasn’t yet returned to service.

The new trains’ locations can be tracked on traintracker.transitmatters.org.

The new trains are a key component of the MBTA’s strategy to increase capacity and reduce wait times between trains on the Red and Orange lines.

In its original contract, the MTBA had hoped to have 152 new cars running on the Orange Line by the beginning of 2022.