Some metallic debris beneath a BART train at Civic Center Station on Sept. 16 caused a giant orange-colored arc of electricity to erupt up one side to the top of the train, but caused only about $600 worth of damage, transit officials said this afternoon.
The still-unknown debris, which probably disintegrated from the heat of the electrical flash, triggered the flash when the train ran over it and 1,000 volts of electricity powering the train emitted a tall arc between the train’s third rail and its running rail.
“Some sort of metallic debris created a short circuit or bridge from the third rail to the running rail,” said Don Allen, BART’s chief engineer, during a news conference at Civic Center station this afternoon. “We believe the debris was consumed. We did find some spatters of molten metal.”
The arc reached about 11 feet high from the bottom of the track, along the side of the train opposite the platform to the top of the train, where it stopped, Allen said.
“It was probably spectacular for someone seeing it,” he said.
BART officials released a surveillance video of the arc and reaction to it from a few passengers on the platform, including a cyclist and a pedestrian who bumped into each other and slipped onto the platform, BART spokesperson Alicia Trost said.
BART officials decided to replace some burnt insulation on the train, at a cost of $200, and two cover boards scorched by the arc for $400, Allen said.
“The wall was scorched, the side of the train had scorch marks, but nothing was actually consumed by the arc,” Allen said.
“These things do happen, about once a year, but not as dramatic as this one,” he said, adding that BART has 225 miles of track and runs more than 500 trains a day.
The train was headed for Pittsburg/Bay Point on the East Bay side of the platform at 1:36 p.m. when two BART police officers “heard a loud noise and saw a bright orange flash form the rear of the train” and started to evacuate passengers from the train and platform, police said.
The evacuation lasted for 62 minutes. The arc did not cause a fire, although it made a loud noise and sent up a small amount of smoke that was cleared about 20 minutes later, Trost said. BART reopened the station at 2:38 p.m.
Jeff Burbank, Bay City News