By Lena H. Sun
Washington Post Staff Writer
Thursday, April 17, 2008
Metro train operators have been instructed to manually open rail car doors after a malfunction in the automatic train control system caused doors to open on the wrong side four times in the past 100 days, officials said yesterday.
There were no injuries to passengers.
"While this problem happens rarely, it is a safety concern," said Metro's rail chief, Dave Kubicek. On average, doors open on Metro trains 216,000 times a day. The incidents, which occurred on the Red and Orange lines, accounted for four in about 22 million times that train doors opened, he said. The problems did not appear to be concentrated on any particular series of the six types of car in the system's fleet, he said.
Train doors typically open automatically based on electronic commands relayed to the train from a signaling system within the track infrastructure. Operators close the doors manually with the push of a button. Since Monday, operators have been opening and closing the doors manually.
Officials said the change will not degrade service; in fact, it could mean fewer instances in which riders have to get off trains which are then taken out of service because of door problems.
Kubicek said the malfunction was triggered by electromagnetic interference caused by ongoing upgrades to power substations and other related infrastructure. Metro needs the upgrades to provide electricity to operate more eight-car trains. In December, Metro started running 20 percent of its fleet as eight-car trains to meet growing ridership.
"What we were seeing is extra noise being generated in the signaling system" that was causing interference, Kubicek said. The safety concern is that such interference could cause doors to open when a train is stopped in a tunnel. The doors cannot open when a train is moving.
The long-term solution will be to install an electrical component in each of the system's 1,066 rail cars to allow the doors to open automatically. The fixes are expected to be completed by fall 2009, officials said.