The National Transportation Safety Board has found that mechanical problems led to a subway derailment in Washington, DC earlier this year that injured 23 passengers.
The Board said that the probable cause of the derailment of the Washington Metropolitan Area Transit Authority (WMATA) train was a wheel climb on a car as it traversed a standard turnout near the Mt. Vernon Square station. The wheel climb was initiated by a rough wheel surface created during maintenance, the Board determined. The accident was also caused by the lack of quality control measures to ensure that wheel surfaces were smoothed during the maintenance procedure, the lack of a guard rail on the No. 8 turnout, and WMATA’s failure to have an effective process to implement safety improvements identified following similar accidents and related research projects.
“We cannot emphasize enough how imperative it is that WMATA adopt and implement the recommendations issued today,” said NTSB Chairman Mark V. Rosenker. “We want to ensure the safest travel possible for the thousands of metrorail riders who commute daily on this system.”
On January 7, 2007, about 3:45 pm, northbound WMATA Greenline Metrorail train 504 derailed one car (the 5th of 6 cars) as it traversed a crossover from track 2 to track 1. About 80 passengers were on board at the time of the accident. Twenty-three passengers were transported to local hospitals for treatment and released.