A feeder cable and conduit damaged during the McPherson Square rail fire on March 14, 2016.
Updated 4:35 p.m.
Metro leaders are conceding they do not know why electrical fires persist in the rail system 14 months after a passenger died and more than 80 were injured when smoke filled their trapped train near L’Enfant Plaza station.
The admission accompanied the release of a report that inspection teams during the Metrorail shutdown on March 16 found more than 300 locations requiring "non-emergency" repairs on or near track-based power cables.
The 338 locations were in addition to the 27 "high priority" defects inspectors identified largely along the Blue, Orange, and Silver Line tracks through downtown Washington, three of which were labeled "show stoppers," or extremely hazardous.
At the 338 "non-emergency" locations, some problems may be related to water or debris near the cables, a matter of routine maintenance, not necessarily defective or dangerous cables, Metro officials said.
"A total of 1,928 cables were inspected, which includes jumper cables, track feeder cables, transition and expansion cables," according to the documents presented to the WMATA board of directors’ safety committee.
The 27 "high priority" defects were repaired and the Metrorail system re-opened to the public on March 17.
Riders get few answers
The extent of the electrical problems, discovered only because Metro general manager Paul Wiedefeld ordered the unprecedented, all-day shutdown of America’s second-busiest subway, raised questions about why the transit authority failed to effectively address the hazard in the year since Carol Glover, 61, of Alexandria died in the L’Enfant Plaza incident of Jan. 12, 2015.
A similar electrical fire near McPherson Square station snarled the morning commute on March 14 and led to Wiedefeld’s decision to shut down the system.
"I couldn’t get those answers, and that is why I didn’t have the confidence to [keep] open the system," the general manager said.
"Either inspections weren’t done or they were done and missed major defects," said Mort Downey, chairman of the WMATA board’s safety committee. "I have no confidence that being told it will be done has anything to do with seeing that it does get done. We seem to have a systemic problem."
Wiedefeld said until the transit authority’s investigation is completed, he would not speculate on the causes. But he did announce the creation of a new team to inspect and maintain track-based electrical cables.
"Clearly, what we have been doing hasn't worked," Wiedefeld said. "We have to find out how this happened after 14 months, how we performed during this event, and do something different going forward."
Potential causes of the electrical fires, known as arcing, have been known for some time. In June, the National Transportation Safety Board issued an urgent finding that electrical connections to the third rail required "immediate action."
"Investigators found that some electrical connections associated with the power supply to the third rail were improperly constructed and installed, which can allow moisture and contaminants to enter the components," the safety board said.
"Such conditions can create the potential for electrical short circuiting, which could result in fire and smoke events in the Washington Metropolitan Area Transit Authority system."
Since the NTSB warning, Metro has fixed roughly half of the thousands of electrical connections that lacked the necessary insulation. Also, inspections were performed last year at the sites of more than 600 third rail jumper cables, the type involved in the electrical arcing incident near McPherson Square station.
It remains unclear whether inspectors failed to identify deteriorating cables or if the cables frayed recently, a focus of the ongoing investigation, Wiedefeld said.
There were 216 reported smoke or fire incidents across Metro in 2015, a large increase from the 104 reported incidents in 2014. However, data was not available on how many involved electric arcing similar to the incidents at McPherson Square last week and at L’Enfant Plaza last year.