OAKLAND (CBS SF) — BART still has no timeline for when service will be restored between the North Concord/Martinez and Pittsburg/Bay Point stations, more than a week after a mysterious electrical spike damaged dozens of cars along that stretch of track.

“We’re a little perplexed right now,” BART assistant general manager Paul Oversier told the BART board of directors at their meeting Thursday morning.

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The voltage spike damages electrical components in certain train cars and took about 50 cars out of service. BART crews have inspected every inch of the tracks in the area and the electrical systems serving it, but have so far not found the source of the problem.

A similar problem damaged cars between downtown Oakland and San Francisco starting in February, but BART crews didn’t get to the bottom of that problem either — it just went away and its cause remains unclear.

So far, this problem hasn’t gone away. During commute hours, riders boarding at the Pittsburg/Bay Point station, which peaks at about 1,700 people hourly, have to board a shuttle train running between that station and North Concord/Martinez every 10 minutes.

Riders then have to off-board and get on a different train to get to other destinations on BART, Oversier said.

“We need to understand how significant this is to people,” BART director Joel Keller, who represents the affected stations, said at Thursday’s meeting.

Keller said he took the shuttle to the meeting and, while it works, “it’s not what people are accustomed to, it’s not what they expect, it’s not the level of service that we have provided people for 20 years. It’s a step down in service.”

He called for an evening meeting in Pittsburg to hear from residents there.

Even as the problem remains mysterious, BART officials are developing a plan to restore full service to the line. Because the glitch only affects cars with older direct current propulsion systems, it’s possible trains made up of cars that run on newer alternating current systems can run through there instead, Oversier said.

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While possible, such a solution is logistically difficult. Only 59 cars capable of leading the trains with alternating current systems are available, and 42 of them would have to be dedicated to running to Pittsburg/Bay Point under such a plan.

Meanwhile, BART is stretched thin trying to keep as many cars as possible on the tracks. After the problem first surfaced at about 10 a.m. on March 16, BART quickly went from 571 cars in service, already down from its typical 579, to 521 cars.

The electrical spikes of up to 2,500 volts last only milliseconds but damage a component called a thyristor in the cars. BART repair crews have quickly run through their supply of spare thyristors, but each car has five of them and the spikes typically only damage one so the remaining four can be used to repair other cars.

As of Thursday, 541 cars were in service, meaning 12 trains were still running one car short, Oversier said.

To get all trains back in service, BART needs to get a new supply of thyristors, something agency officials thought initially could take 22 weeks. However, they have now found a supplier that might be able to get them in four weeks.

Three outside consultants, extensive inspections of the tracks and new diagnostic equipment have not been able to find the source of the mysterious power surges.

Because nothing on the tracks seems to be causing the problem, BART crews are now looking into the unlikely possibility that the problem is originating in the cars themselves. But that possibility is only being looked at because no other cause has become clear.

BART general manager Grace Crunican apologized to riders Thursday and said sleep-deprived BART staff have been working overtime to determine the cause of the issue and get service restored as quickly as possible.

“They look like hell,” Crunican said.

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