WASHINGTON METRO CRASH 6-22-09
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NINE DEAD, SCORES INJURED IN WASHINGTON METRO CRASH: A Washington Metro train struck another train on the same Red Line track at the height of the evening rush hour near the Fort Totten station June 22, killing at nine and injuring 70 others in the deadliest accident in Metrorail's 33-year-history, reports the Washington Post. Both six-car trains were headed toward downtown Washington. The crash occurred just after 5 p.m., and traffic on the train lines and highways was severely affected. The impact of the crash was so powerful that the trailing train was left atop the first train. Firefighters had to use heavy rescue equipment to cut open the cars to reach people trapped inside, and D.C. Mayor Adrian M. Fenty said fire officials were still going through the trains last night to make sure they had recovered all the bodies. [United Transportation Union, 6-22-09, from Washington Post report]
FAULTY ELECTRONIC RELAYS EYED IN METRO CRASH: Experts familiar with Washington Metro's operations focused on a failure of the signal system and operator error as likely causes of yesterday's fatal Red Line crash, reports the Washington Post. Metro was designed with a fail-safe computerized signal system that is supposed to prevent trains from colliding. The agency's trains are run by onboard computers that control speed and braking. Another electronic system detects the position of trains to maintain a safe distance between them. If they get too close, the computers automatically apply the brakes, stopping the trains. These systems were supposed to make yesterday's crash impossible. But four years ago, in an episode eerily similar to yesterday's, the signal system briefly failed in the tunnel between Foggy Bottom and Rosslyn, forcing two quick-thinking operators to stop their trains manually to avoid a crash. Experts said the train appeared to be traveling fast before impact because the force pushed the first car of the train on top of the train ahead. Witnesses on the train that crashed also reported that the train did not brake before impact. Other possible factors in the crash include a medical emergency that incapacitated the operator or a catastrophic failure of the braking system. [United Transportation Union, 6-23-09, from Washington Post report]
COMPUTER FAILURE MAY HAVE CAUSED D.C. CRASH: Investigators looking into the deadly crash of two Metro transit trains have focused on why a computerized system failed to halt an oncoming train, and why the train failed to stop even though the emergency brake was pressed. At the time of the crash, the train was also operating in automatic mode, meaning it was controlled primarily by computer. In that mode, the operator's main job is to open and close the doors and respond in case of an emergency. The train plowed into a stopped train ahead of it at the height of the Monday evening rush hour, killing nine people and injuring more than 70. It was the deadliest accident in the 30-year history of the Metro. On Tuesday, all Metro trains were running on manual control as a precaution against computer malfunction. [United Transportation Union, 6-24-09, from Associated Press report]
METRO OPERATOR MADE FAILED BID TO STOP TRAIN: The operator of the Metro train that slammed into a stationary train in front of it apparently had activated the emergency brakes in a failed effort to stop before the accident, federal officials said yesterday as they searched for the cause of Monday's Red Line wreck that killed nine and injured 80. Debbie Hersman of the National Transportation Safety Board said the emergency brake button was depressed, and the steel rails showed evidence that the brakes were engaged. Investigators also said the striking train was in automatic mode, which means onboard computers should have controlled its speed and stopped it before it got too close to the stationary train. In addition, Metro sources said, the first two cars of that train were two months overdue for scheduled maintenance of some braking components. Taken together, experts say these facts point to several possible scenarios: The operator activated the brakes too late; the computers that are supposed to stop a train from getting too close to another train faltered; the train's brakes failed; or some combination of those. Some passengers on the striking train have said that they never felt the train slow down. Investigators are also delving into the automatic train protection system, which is designed to make collisions impossible. Had the system been working correctly, it would have sensed that Train 112 was getting too close to Train 214 and directed the brakes aboard Train 112 to engage. [Brotherhood of Locomotive Engineers & Trainmen, 6-24-09, from Washington Post report]
WASHINGTON METRO FAILED TO DETECT CIRCUITRY MALFUNCTION: Five days before last week's deadly Red Line accident, a Metro crew replaced a key piece of equipment designed to prevent crashes, but the circuitry malfunctioned and no one at Metro detected the problem, investigators and transit officials said. The findings raise new questions about whether Metro officials should have discovered the hazard before one train rammed into another June 22, killing nine and injuring 80. It also puts a spotlight on Metro's maintenance crews and the design of a highly automated subway system that is supposed to be "fail-safe." Transit officials would not say whether they believe the malfunction was a result of faulty equipment or poor installation, citing the investigation by the National Transportation Safety Board. In the aftermath of the crash on the Red Line between the Takoma and Fort Totten stations, Metro officials analyzed track circuit data and found that one circuit in the crash area intermittently lost its ability to detect a train. The circuit would report the presence of a train one moment, then a few seconds later the train would "disappear," only to return again. [Brotherhood of Locomotive Engineers & Trainmen, 7-2-09, from Washington Post website report]
D.C. METRO SYSTEM HAD CHRONIC SIGNAL PROBLEM, NTSB SAYS: The signaling system that detects a train on the tracks of Washington's Metro system has been having problems for a year and a half in the area of a crash that killed nine, National Transportation Safety Board investigators said. Records show the system on the track circuit had been intermittently malfunctioning, whether a train was present or not, since a piece of equipment was replaced in December 2007. [United Transportation Union, 7-23-09, from Associated Press report]
NTSB IDENTIFIES SIGNAL FAILURE IN FATAL METRO CRASH: The National Transportation Safety Board (NTSB) on September 22 issued nine safety recommendations, six of which are urgent, to address concerns about the safety of train control systems that use audio frequency track circuits. The recommendations are the result of NTSB's ongoing investigation into the collision between two Washington Metropolitan Area Transit Authority (WMATA) trains on the Red Line near the Fort Totten station in Washington, D.C., on June 22, 2009. During the investigation, the NTSB has discovered that a failure occurred in which a spurious signal generated by a track circuit module transmitter mimicked a valid signal and bypassed the rails via an unintended signal path. The spurious signal was sensed by the module receiver which resulted in the train not being detected when it stopped in the track circuit where the accident occurred. The NTSB made specific recommendations to the Washington Metropolitan Area Transit Authority and to Alstom Signaling, Inc., the manufacturer of the track circuit modules at the Fort Totten station, to examine the WMATA track circuits and work together to eliminate adverse conditions that could affect the safe performance of these systems. Additionally, the NTSB called upon WMATA to develop a program to periodically determine that the electronic components in its train control systems are performing within design tolerances. Although the NTSB's investigation is not yet complete and no determination of probable cause has been reached, the NTSB is concerned about the safety of train control system circuitry used in comparable rail and transit operations in other parts of the country. Therefore, the NTSB recommended that the Federal Transit Administration (FTA) and the Federal Railroad Administration (FRA) advise all rail transit operators and railroads that use audio frequency track circuits in their train control systems about these findings from the Fort Totten accident investigation. The NTSB also recommended that the FTA and FRA have transit operators and railroads that use audio frequency track circuits examine their track circuits and work with their signal equipment manufacturer(s) to eliminate adverse conditions that could affect the safe performance of these systems, and to develop programs to periodically determine that the electronic components in their train control systems are performing within design tolerances. "After only 3 months, this complex investigation is far from complete, so we are not ready to determine the probable cause of the accident on WMATA," said Chairman Deborah A.P. Hersman. "However, our findings so far indicate a pressing need to issue these recommendations to immediately address safety glitches we have found that could lead to another tragic accident on WMATA or another transit or rail system." In accordance with NTSB protocol, the letters were addressed to the heads of each organization with a request for a response from each organization within 30 days on the urgent recommendations, addressing the actions taken or planned in response to the Board's recommendations. [National Transportation Safety Board, 9-22-09]
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