BART has completed its preliminary investigation into a Sept. 16 incident in which a large 1000 volt arc of electricity adjacent to a train entering Civic Center Station created smoky conditions and required the evacuation of the train and the station. Based on preliminary findings, the BART System Safety Department has concluded that the arc was most likely caused by the train striking trackside debris capable of conducting electricity. BART will be reviewing the incident with the California Public Utilities Commission and Muni Metro, which shares the station with BART.



The 1000 volt arc caused a bright flash of light, loud sounds and smoke. The incident was over in less than 30 seconds. It did not cause any significant damage to BART equipment. There have been two reported complaints of smoke inhalation.



An electrical arc is a discharge of current, which can be brief but very bright, when a strong current jumps across a gap in a circuit. “This was not a fire in the sense of flames burning any solid material or causing any structural damage, but the bright flash of the arc has a fiery appearance,” said Chief Engineer Don Allen. “There was a cloud of heavy smoke so it is understandable that to some passengers it seemed like fire.”



The 1000 volts of electricity used to power BART trains is supplied through an electrified third rail that is supported at 10 foot intervals by porcelain insulators. A collector shoe extending from the bottom of the train car contacts the third rail, completing the electrical circuit. If there is a gap in this circuit for any reason, the electrical current can arc to ground. Arcs similar to those of Sept. 16 have occurred before on BART but are a relatively infrequent occurrence. Minor arcing between the car collector shoe and the third rail has been observed on BART trains operating outdoors at night.



On Sept. 16, all the passengers exited the train under their own power. Civic Center Station was closed for about one hour after the 1:36 pm incident for all equipment to be checked out and cleared for safety.



“BART Police Officers, San Francisco Fire Department Firefighters and other trained personnel on the scene made sure passengers got out safely,” said BART Police Chief Kenton W. Rainey. “We appreciate the level-headedness of our customers and responsiveness of emergency personnel to remedy the situation quickly.”



“The safety of our passengers is our top priority. We apologize for the inconvenience and for those passengers who were startled by the arc and smoke. All our front line personnel undergo extensive training and we conduct regular inspections to make sure our equipment meets safety standards,” said BART General Manager Grace Crunican. “Passengers can help keep our tracks free of debris by not bringing food or trash into our stations. We encourage all BART riders to review the posted safety procedures in the unlikely event they should ever experience an emergency situation in their travels.”



A guide to emergency procedures is posted on each train car and a guide to safety can be found on the BART website at http://www.bart.gov/safety

TIMELINE OF INCIDENT