The National Transportation Safety Board today determined that the head-on collision between two freight trains in Texas last year stemmed from a mistake by the railroad dispatcher, but the Board cited procedural and training problems at the dispatching center in its probable cause of the accident.
On June 22, 1997, two Union Pacific Railroad (UP) freight trains collided head-on in Devine, Texas, killing a crewmember from each train and two other persons suspected of being transients who were riding one of the trains.
The trains were operating on a single main track with passing sidings in unsignalized (dark) territory in which train movement was governed by conditional track warrants through a dispatcher. Estimated damage to the equipment and track exceeded $6 million.
The southbound train was issued a conditional track warrant that required it to remain in Gessner, Texas until the northbound train passed by before it was permitted to proceed farther south. Recorded radio communications examined during the NTSB's investigation revealed that the UP dispatcher, located at the railroad's Harriman Dispatch Center in Omaha, Nebraska, neglected to read the line of the track warrant that told the crew the conditional nature of the authority. When the train crew read back the warrant, as required by procedure, the dispatcher failed to detect that the crucial information from that line was not verbalized.
The Board said that this occurred because "the UP management had not established and implemented workload policies and operational procedures to ensure a safe dispatching system, and the Federal Railroad Administration had failed to provide standards and oversight in all aspects of train dispatching operations."
The dispatcher involved in this accident had been working in his dispatching position for just under a year. The Safety Board said that UP should assign territories to dispatchers based on their levels of experience. Traffic on the Austin subdivision, in which this accident occurred, has virtually doubled since 1990.
The Board said, "Such territories often pose operational challenges to even the most experienced dispatchers. Veteran dispatchers reported that under conditions of high-operating demands, less experienced dispatchers may issue track warrants while mentally or physically attending to their next task and not concentrating on the read-back communication from the train crewmembers."
The NTSB concluded, "The Union Pacific Railroad may have jeopardized safe dispatching operations by qualifying unprepared apprentice dispatchers and assigning less experienced dispatchers to territories of high-operating demands."
The Board recommended that the FRA not permit the practice of after-arrival conditional warrants, saying the practice "creates an inherent danger." Should a failure occur in the transmission or comprehension of a track warrant that results in the omission or inaccurate communication of the condition, as happened in this case, two opposing trains may occupy the same block of track at the same time. A similar recommendation was issued to the railroad.
The Board also noted that, despite previous NTSB recommendations, the "FRA has failed to develop dispatcher standards and needs to accelerate the establishment of regulatory standards for train dispatchers."
Contributing to the accident, the Board said, was the lack of a positive train separation (PTS) control system that would have prevented the collision. PTS is an item on the Board's Most Wanted list of safety improvements. The Board reiterated this 11-year-old recommendation to the FRA.
Of the 5 event recorders on the two trains, only two provided usable data for the investigation. The Board recommended that the FRA implement event recorder crashworthiness standards by January 1, 2000.
The Board issued 14 new recommendations in all in today's final report, eight to the Union Pacific Railroad, five to the FRA and one to the State of Texas.
The NTSB's complete accident report, PB98-916302, may be purchased from the National Technical Information Service, 5285 Port Royal Road, Springfield, Virginia 22161, (703) 487-4650. The report will also be placed in the near future on the Board's web page, www.ntsb.gov.