NTSB issues Investigative Update for MBTA collision

The rear of the trailing car of the Green Line MBTA train struck by another Green Line train is seen in this image taken July 31,2021.

NTSB/Joe Gordon

Following up on an earlier story regarding the collision of two MBTA Green Line trolleys, the NTSB has issued an Investigative Update around the accident.

Follow this link to read yesterday’s story.

Here is the text of the most recent update:

“The National Transportation Safety Board’s investigation of Friday’s collision of two Massachusetts Bay Transportation Authority light rail trains continues Monday as investigators gather information and evidence.

“On July 30, 2021, at approximately 6:03 p.m., a westbound MBTA Green Line train collided with the rear of a MBTA Green Line train that was also westbound on the track ahead. Twenty-seven people, including MBTA personnel, were transported to the hospital with non-life threatening injuries.

“NTSB investigators arrived on scene Sunday. The investigative team consists of members from:

• Federal Transit Administration,
• Massachusetts Department of Public Utilities, and
• MBTA

“NTSB has also offered party status to the labor union that represents employees of MBTA.

“The investigator-in-charge formed technical working groups including operations, human performance, system safety, mechanical, vehicle performance and track.

“Information gathered to date in the investigation includes:

• The accident occurred on the Commonwealth Avenue rail grade crossing leading into the Pleasant Street Station, which is currently closed and under construction.
• The striking train was traveling on an ascending grade, going from lower ground to higher ground, at the time of the accident.
• As a result of the collision, two cars of the leading train and one car of the trailing train derailed.
• Investigators secured data from the event recorder from the operating car of the striking train. The event recorder holds the data regarding the operations of train (i.e. speed, brake application, door positions, horn use, etc.).
• Preliminary review of the event recorder data indicated that the train that was hit was traveling at approximately 10 mph. The striking train overtook the other train at approximately 30 mph.

“The above information is preliminary and subject to change as the investigation is ongoing. NTSB investigators will continue to gather facts throughout the on scene portion of the investigation. NTSB will issue a preliminary report within 30 days of completing on scene work.”