Early findings indicate that improperly held together rail ties and tracks that were too far apart are to blame for last week’s Silver Line derailment, the National Transportation Board said.
The derailment occurred about 50 feet away from the East Falls Church station platform on July 29. Of the 75 passengers on board the train, three were injured. All have recovered.
The distance between the rails of the tracks at the interlocking near the East Falls Church Metro station was too far apart by almost two inches, NTSB investigators said.
WMATA standards require tracks be removed from service if the distance between the rails is greater than 57 ¼ inches. At the site of the derailment, NTSB investigators found tracks to be 59 inches apart.
The NTSB also found more than 30 feet of track with no effective crossties. WMATA standards call for no more than 10 feet between non-defective ties.
In response to the NTSB investigation, WMATA told officials it will accompany track inspectors during crossover inspections, include crossover sites in main line track inspections and will inspect crossover sites twice weekly.
