Massachusetts Bay Transportation Authority officials say they will now more closely inspect the bolts and rivets that hold together the panels of its subway trains, after a panel fell off an Orange Line train Tuesday night, causing riders to kick through windows to escape smoke filling some of the station.
State transportation officials said they would now inspect such fasteners closely as part of regularly scheduled maintenance. They said they had previously done visual inspections but would now physically check them.
“Following last night’s incident involving two Orange Line trains, the MBTA is immediately incorporating inspection of body panel hardware as part of regular maintenance work on Orange Line cars,” the T’s general manager, Frank DePaola, said in a statement.
The incident underscores the persistent reliability problems on the Orange Line, which uses a fleet of 120 cars that were put into service between 1979 and 1981. Though the Orange Line cars aren’t the oldest of the T’s subway cars, the MBTA has not rebuilt the cars as it has with older Red and Green Line vehicles.
Tuesday night appeared to be a chaotic scene at the State Street station, with some passengers eventually kicking through windows to exit the train.
Officials believe that at about 8:30 p.m., a 1-by-12-foot panel fell off an Orange Line train onto the tracks because of deteriorating fasteners. The train ran over the panel, disabling the train and causing smoke after the panel hit the third rail, officials said. Passengers were then evacuated from the train.
About six minutes later, another train struck the same panel, and more smoke filled the station. Because the train was not properly stopped at the station, the doors were automatically locked and passengers began kicking out the windows to crawl out and escape.
Officials said no injuries were reported, and they do not know how many people were on the train.
“There will be a full investigation into all aspects of the incident,” Jeffrey Gonneville, the MBTA’s chief operating officer, said in a statement.
MBTA officials said that out of an abundance of caution, workers checked every train Tuesday night and secured 13 panels on the cars. Because the panels are unique to the Orange Line trains, other vehicles will not be inspected for the problem.
The MBTA conducts regular maintenance on the Orange Line trains every 12,000 miles, or about eight or nine weeks, and the Orange Line cars’ panels will now be regularly checked for deterioration on the fasteners.
Transit agencies largely set their own inspection routines. The Federal Transit Administration does not require the MBTA to have a specific inspection routine, only that the agency keep its own maintenance plan on file to keep the federally funded vehicles in good working condition, according to an FTA spokesman.
The incident marked the second time in a little over a year that a smoke-filled train caused panic on an MBTA subway train.
In January, frantic passengers kicked out the windows of a Red Line car at the Quincy Center station to escape a dark, smoking train. In that case, the burst of smoke was caused by a failure in the propulsion system.
According to publicly available statistics on the T’s subway lines, the Red Line and Orange Line often battle it out for the least reliable fleet (the statistics exclude the Green Line, which is a light rail trolley system).
From Feb. 8 to 14, the MBTA was rarely able to run more than 80 percent of its Orange Line trains on time.
MBTA officials are already planning to replace cars from both fleets: Under the previous administration, the former state transportation department board voted in 2014 to award a $566.6 million contract to a China-owned company to build new Red and Orange line cars.
In September, a top executive from the company, now called China Railway Rolling Stock Corp., joined Governor Charlie Baker and Transportation Secretary Stephanie Pollack in Springfield, where they broke ground on a facility that will assemble the cars.
The delivery of the first new Orange Line cars is scheduled for 2018. Four new cars are expected to be delivered each month until 2022.