The National Transportation Safety Board (NTSB) released its preliminary report on the Amtrak 501 accident in Washington state and explains that positive train control (PTC) could have prevented the over speed condition.
The train, which was carrying 77 passengers and five Amtrak employees on its inaugural run along a new route, derailed on a 30 mph curve with its last recorded speed being 78 mph. The lead locomotive, the power car and two passenger railcars derailed onto Interstate 5 below the right-of-way. Three train passengers were killed and another 70 people, including eight on the highway, were injured in the accident.
NTSB says it has not been able to interview the engineer or qualifying conductor, both in the lead locomotive cab at the time of the incident, due to injuries the two men sustained. NTSB was able to obtain the lead locomotive’s event data and video recorders and the agency notes that the two crew members in the cab did not appear to use any personal electronic devices and the engineer did comment on an over speed condition about six seconds prior to the derailment.
NTSB says a 30-mph speed sign, was posted two miles before the curve on the engineer’s side of the track, with another 30-mph speed sign on the wayside at the beginning of the curve on the engineer’s side of the locomotive. The agency also explains that had PTC been operational on the line, the engineer would have been alerted to slow the train and if no action was taken, PTC would have applied the brakes.
NTSB says the investigation is ongoing and will determine a probable cause of the accident at a later date.