(Source: Washington Post)

The crash-avoidance system suspected of failing in the recent deadly accident on Metro’s Red Line malfunctioned three months earlier, when a rush-hour train on Capitol Hill came “dangerously close” to another train and halted only after the operator hit the emergency brake, newly obtained records show.

At the time of the March 2 incident, the train operator and control-center supervisors did not know that anything serious was wrong, the records indicate. The operator applied the brake because he realized that the train was not slowing fast enough and would overrun the station platform, a fairly common occurrence. About a week later, while reviewing computer logs, officials determined that there was a problem with the Automatic Train Protection system and that the train had stopped just 500 feet behind another.

Despite repeated promises of greater openness about safety, Metro officials did not make public the near miss at the Potomac Avenue Station, and federal investigators said Metro did not tell them about it after the Red Line crash, which killed nine people and injured 80.

The National Transportation Safety Board, which is investigating the June 22 crash, learned of the March incident last week when notified by the little-known Tri-State Oversight Committee, said NTSB spokeswoman Bridget Serchak. Metro officials did not immediately respond to questions about why they did not notify the NTSB.

The Washington Post discovered the incident while reviewing documents obtained through a public records request filed with the oversight committee, which was created 12 years ago to monitor Metro.

“If a part goes down on the car, it’s not necessarily related to the part that’s on the track,” said Farbstein, who described the March and June incidents as “very, very different.”

Farbstein said the March incident, which took place at 4 p.m. on a Monday as a train on the Orange Line headed toward Vienna, was caused by a single failed relay on a subway car that has been fixed. The car was a 1000 series model, the same kind of car on the striking train in the June crash. The June crash is suspected of being caused by a faulty track circuit. Either problem could lead to a temporary failure of the Automatic Train Protection, a fail-safe system that monitors train locations and is supposed to automatically stop a train if it senses it is too close to another.

Farbstein said that in response to the March event, Metro examined relays on its entire fleet of more than 1,000 rail cars and identified only “one relay that could be tied to the incident.”

After the June crash, Metro officials said that the malfunctioning track circuit at the accident site was “a freak occurrence” and that they were unaware of other incidents, including near misses, that stemmed from failures in the safety system.

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