A formerly unsolved power problem that led to months of commute delays last year appears to be back, according to a report from ABC 7 News.
BART was working round-the-clock last Friday night to identify and fix the mysterious issue that damaged 22 cars between North Concord and Pittsburg - Bay Point stations in California. Now, BART officials believe metallic dust is to blame.
Power surges knocked out nearly two dozen train cars in the East Bay Friday, and two similar incidents last year.
The power issues afflicting the 22 cars on Friday and last year appear to the be the result of a combination of factors, according to a report from The Mercury News. One issue is the buildup of metallic dust on the underside of cars impacted by the electrical surging, he said.
BART generates metallic dust from grinding the rails, a practice the agency uses to reduce the screeching noise of wheels grating against the tracks, the spokesman said. The dust can conduct electricity, which becomes susceptible to flashes as the cars draw power from the track’s third rail.
BART engineers noticed the dust was thickest near tunnels and inside the Transbay Tube, where rain and wind cannot naturally wash it away. So, in response to the surging issues near the West Oakland station last year, crews started vacuuming the tracks after grinding the rails to remove some of that dust, a BART spokesman told The Mercury News.
The agency hadn’t been as concerned with the dust at its above-ground stations, the spokesman said, because the dust is removed naturally by rain and wind. But over the course of the last month, BART workers had been diligently grinding the rails four nights a week between the North Concord and Pittsburg stations.
That stretch of tracks is a little different than the rest of the BART system because it’s on a hill, meaning the trains need a little extra juice to make it up and over.
“This particular section of track was designed to provide more power to trains than anywhere else on the BART system,” the spokesman said. “It is now thought that this rail grinding led to a buildup of metallic dust on rail cars.”
To address the issue, BART is in the process of purchasing magnets, which will sit on train cars that aren’t carrying passengers to pick up the metallic dust left in the rail grinders’ wake, a solution that should be implemented as soon as next month.