The malfunctioning circuit that investigators are examining in connection with a deadly June 22 Metro train crash had been failing intermittently since December 2007, the National Transportation Safety Board said Thursday.
A component of the track circuit, which is part of a system that monitors the location of trains in the system, was replaced 19 months ago and had been experiencing problems periodically since, the NTSB said, citing Metro maintenance logs.
The investigation had already determined that a similar component, which didn’t indicate the presence of a train, on the other end of the same circuit had been replaced five days before the crash that killed nine people and injured more than 80 others.
Investigators said they have requested 18 months of “trouble tickets” to determine whether the problems had been reported and they are seeking additional records that would indicate whether any train operators voiced concern about similar problems.
After the accident, Metro officials began reviewing operations data and identified some problems at other circuits.
The NTSB said investigators and Metro officials are looking at the problems to determine whether they are the same kinds of problems as were found in the location of the accident site. Already NTSB has identified possible sources for the communication interference including electromagnetic interference and system upgrades and changes. After testing, NTSB and Metro have found that circuit problems occur most frequently during rush hour.
At a press conference Thursday afternoon, Metro General Manager John B. Catoe Jr. said the NTSB’s latest report does not mean that the system has widespread problems.
“Though we have found anomalies in other areas of the rail system, we have not found anything that resembles the magnitude of the track circuit problem at Fort Totten [crash site],” he said. “It’s important to know that an anomaly does not necessarily indicate failure in the track circuitry or train detection system. It’s like when a doctor does an EKG on your heart. A blip in the data doesn’t mean you’re having a heart attack, but the doctor may want to conduct more tests.”
In response to the accident, Metro has increased its monitoring of the entire line, Mr. Catoe said, noting that after the crash all 3,000 circuits were tested and three were adjusted as a result.
The NTSB is continuing its investigation into the crash. Two signal companies, Ansaldo STS USA and Alstom Signaling Inc., that designed and manufactured the components for Metro are providing assistance to investigators.
Also on Thursday, the House passed a $150 million appropriations bill, which requires matching funds from Maryland, Virginia and the District, that will help speed much-needed repairs.