The broken section of rail that delayed thousands of BART commuters last week may be among a batch of bad rail, according to preliminary findings by the agency.
“We have a potential rail problem,” BART Assistant General Manager Paul Oversier said Thursday. “We’re looking into all the rail associated with that manufacturing batch.”
The dire warning was among many other as-of-yet unconfirmed findings revealed since a 10-inch piece of broken rail was found between 16th Street and Civic Center BART stations May 6, causing a Bay Area-wide delay.
At the BART board of directors’ regular meeting Thursday, Oversier briefed the board on what the agency thinks may have caused the rail to break.
“There’s a lot we don’t know at this point,” Oversier told the board, but “there’s a few things we do know.”
He strongly cautioned the findings are early, and may change with new information.
BART’s initial guesses on what led to the railway breaking were “dead wrong,” he said.
Oversier said the rail that broke was curved, and installed in 2011. The rail was in good shape, so the break may not be due to a case of worn rail. Oversier said the agency is investigating if the rail was part of a bad batch, and is inspecting other rail bought from the same manufacturer, which he could not immediately identify.
A BART contractor that performs annual ultrasonic rail testing for the agency did identify that section of track as problematic in September — but it did not report it to BART.
“We asked, ‘What’s the story with this?’” Oversier said.
After last week’s incident, contractor Sperry Rail Service acknowledged to BART it had found the anomaly at that section of the track during its annual inspection. When Sperry Rail Service went to visually inspect it saw the railway had a lot of “slag.” Oversier explained slag is “excess material” from welding.
“Usually, you should knock it off and grind it instead of leaving it there” when welding, Oversier told the board. The BART welders had not done so. “It’s bad housekeeping,” he said.
The slag itself did not break the rail. But when Sperry inspectors saw the slag, they believed it was what caused the anomaly in their ultrasonic tests. So the anomaly went unreported.
“That’s Sperry’s story,” Oversier told The Examiner.
BART is conducting independent lab tests on the broken section of track, the results of which may be presented to the board at their next regular meeting. Sperry is scheduled to conduct new ultrasonic tests of BART’s railway this month.