BOSTON (WHDH) - The MBTA announced Monday that the derailment of a decades-old Red Line train in June was caused by a fractured axle.
The fracture likely developed due to poor electrical connectivity between the ground brush and ground ring, a related part that helps keep the train electrically grounded, according to MBTA deputy general manager Jeff Gonneville.
The train’s axle reached that condition as a result of gaps in routine inspection schedules, Gonneville said. Stray electrical arcing on the surface of the 27-year-old axle made it harden and become fragile over time until it broke.
No one was injured when the train derailed near the JFK-UMass station on June 11 but several signal bungalows were badly damaged, resulting in major delays and criticism of the system.
Red Line trains were forced to operate at reduced speeds while crews manually managed subway traffic.
Service has improved on the line but regular service is not expected to return until October.
Red Line trains are said to be inspected every 8,500 miles or once every three months.
MBTA workers have since inspected ground rings in its two oldest fleets of Red Line cars.
The train that derailed had been in service since 1969.
BREAKING: cause of June 11 red line derailment released. Poor electrical connectivity caused an “axle fracture.” This part of the train has not been inspected routinely. Going forward the @MBTA says it will do more comprehensive inspections. #7news
— Sharman Sacchetti (@SharmanTV) September 16, 2019
The T says the last inspection of that particular red line train was in May, 2019. It’s one of the older trains in the fleet
— Sharman Sacchetti (@SharmanTV) September 16, 2019
(Copyright (c) 2024 Sunbeam Television. All Rights Reserved. This material may not be published, broadcast, rewritten, or redistributed.)