SEPTA working to avoid deadly signal error

SEPTA has started using new procedures to make sure a signal error cannot cause the kind of deadly crash on the Market-Frankford Line that killed nine people on the Washington transit system in June.

Federal investigators issued urgent safety recommendations Tuesday about the train control system involved in the Washington Metro crash.

The investigators said a possible design problem in an automated control system could have been a factor. SEPTA's Market-Frankford Line uses an automated control system made by the same company, Alstom Signaling.

In the June 22 crash, a false signal from equipment in a train control room near the accident site told the automated crash-avoidance system that the track was clear. In fact, a train was idling there.

An approaching train struck the stopped train, killing nine and injuring 80.

SEPTA said today that it was testing track signal circuits and adding a test to focus on any possible "unintended signal paths."

In addition, SEPTA said, it has "initiated new procedures" to immediately identify and react to any signal malfunctions that might fail to indicate the presence of a train. In such an event, a train would automatically be halted, SEPTA said.

SEPTA said that because of its new procedures, coupled with inspection and maintenance of its signal equipment, it "believes the Automatic Train Control system presently employed in our Blue Line train operations are safe."

The issuance of the safety recommendations by the National Transportation Safety Board was first reported by the Washington Post.