Railroad Accident Report

Collision of Union Pacific Railroad Train MHOTU-23 With BNSF Railway Company Train
MEAP-TUL-126-D With Subsequent Derailment and Hazardous Materials Release

Macdona, Texas
June 28, 2004

NTSB Number RAR-06/03
NTIS Number PB2006-916303
Adopted July 6, 2006
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Executive Summary

About 5:03 a.m., central daylight time, on Monday, June 28, 2004, a westbound Union Pacific Railroad (UP) freight train traveling on the same main line track as an eastbound BNSF Railway Company (BNSF) freight train struck the midpoint of the 123-car BNSF train as the eastbound train was leaving the main line to enter a parallel siding. The accident occurred at the west end of the rail siding at Macdona, Texas, on the UP's San Antonio Service Unit. The collision derailed the 4 locomotive units and the first 19 cars of the UP train as well as 17 cars of the BNSF train. As a result of the derailment and pileup of railcars, the 16th car of the UP train, a pressure tank car loaded with liquefied chlorine, was punctured. Chlorine escaping from the punctured car immediately vaporized into a cloud of chlorine gas that engulfed the accident area to a radius of at least 700 feet before drifting away from the site. Three persons, including the conductor of the UP train and two local residents, died as a result of chlorine gas inhalation. The UP train engineer, 23 civilians, and 6 emergency responders were treated for respiratory distress or other injuries related to the collision and derailment. Damages to rolling stock, track, and signal equipment were estimated at $5.7 million, with environmental cleanup costs estimated at $150,000.

Probable Cause

The National Transportation Safety Board determines that the probable cause of the June 28, 2004, collision of Union Pacific Railroad train MHOTU-23 with BNSF Railway Company train MEAP-TUL-126-D at Macdona, Texas, was Union Pacific Railroad train crew fatigue that resulted in the failure of the engineer and conductor to appropriately respond to wayside signals governing the movement of their train. Contributing to the crewmembers? fatigue was their failure to obtain sufficient restorative rest prior to reporting for duty because of their ineffective use of off-duty time and Union Pacific Railroad train crew scheduling practices, which inverted the crewmembers work/rest periods. Contributing to the accident was the lack of a positive train control system in the accident location. Contributing to the severity of the accident was the puncture of a tank car and the subsequent release of poisonous liquefied chlorine gas.

The safety issues identified during the investigation of this accident are as follows:

Recommendations

As a result of its investigation of the June 28, 2004, collision and derailment in Macdona, Texas, the National Transportation Safety Board makes the following safety

New Recommendations

To the Federal Railroad Administration:

  1. Require railroads to use scientifically based principles when assigning work schedules for train crewmembers, which consider factors that impact sleep needs, to reduce the effects of fatigue. (R-06-14)
  2. Establish requirements that limit train crewmember limbo time to address fatigue. (R-06-15)

  3. To the Union Pacific Railroad:

  4. Use the Macdona collision as a case study in fatigue awareness training to illustrate the shared responsibilities of the carrier to provide an employee the opportunity for adequate sleep and of the employee to acquire sleep sufficient to work at a safe level of alertness, and the options available if adequate sleep is not obtained. (R-06-16)

  5. To the Brotherhood of Locomotive Engineers and Trainmen and the United Transportation Union:

  6. Use this accident as a fatigue case study to illustrate the responsibility of the carrier to provide an employee the opportunity for adequate sleep and the responsibility of the employee to acquire sleep sufficient to work at a safe level of alertness, and the options available if adequate sleep is not obtained. Present this case study to your members at meetings, through written materials, and other appropriate methods. (R-06-17)

Recommendations Reiterated in This Report

To the Federal Railroad Administration:

R-04-4
Conduct a comprehensive analysis to determine the impact resistance of the steels in the shells of pressure tank cars constructed before 1989. At a minimum, the safety analysis should include the results of dynamic fracture toughness tests and/or the results of nondestructive testing techniques that provide information on material ductility and fracture toughness. The data should come from samples of steel from the tank shells from original manufacturing or from a statistically representative sampling of the shells of the pre-1989 pressure tank car fleet.

R-04-5
Based on the results of the Federal Railroad Administration's comprehensive analysis to determine the impact resistance of the steels in the shells of pressure tank cars constructed before 1989, as addressed in Safety Recommendation R-04-4, establish a program to rank those cars according to their risk of catastrophic fracture and separation and implement measures to eliminate or mitigate this risk. This ranking should take into consideration operating temperatures, pressures, and maximum train speeds.

R-04-6
Validate the predictive model the Federal Railroad Administration is developing to quantify the maximum dynamic forces acting on railroad tank cars under accident conditions.

R-04-7
Develop and implement tank car design-specific fracture toughness standards, such as a minimum average Charpy value, for steels and other materials of construction for pressure tank cars used for the transportation of U.S. Department of Transportation class 2 hazardous materials, including those in ?low-temperature? service. The performance criteria must apply to the material orientation with the minimum impact resistance and take into account the entire range of operating temperatures of the tank car.

R-05-16
Require railroads to implement operating measures, such as positioning tank cars toward the rear of trains and reducing speeds through populated areas, to minimize impact forces from accidents and reduce the vulnerability of tank cars transporting chlorine, anhydrous ammonia, and other liquefied gases designated as poisonous by inhalation.

R-05-17
Determine the most effective methods of providing emergency escape breathing apparatus for all crewmembers on freight trains carrying hazardous materials that would pose an inhalation hazard in the event of unintentional release, and then require railroads to provide these breathing apparatus to their crewmembers along with appropriate training.

Recommendations Reclassified in This Report

To the Federal Railroad Administration:

R-04-4
Conduct a comprehensive analysis to determine the impact resistance of the steels in the shells of pressure tank cars constructed before 1989. At a minimum, the safety analysis should include the results of dynamic fracture toughness tests and/or the results of nondestructive testing techniques that provide information on material ductility and fracture toughness. The data should come from samples of steel from the tank shells from original manufacturing or from a statistically representative sampling of the shells of the pre-1989 pressure tank car fleet. Safety Recommendation R-04-4, previously classified "open—Unacceptable Response," is reclassified "Open—Acceptable Response" in the "Previous Safety Board Actions Regarding Tank Cars" section of this report.

To the Federal Railroad Administration:

R-04-7
Develop and implement tank car design-specific fracture toughness standards, such as a minimum average Charpy value, for steels and other materials of construction for pressure tank cars used for the transportation of U.S. Department of Transportation class 2 hazardous materials, including those in "low-temperature" service. The performance criteria must apply to the material orientation with the minimum impact resistance and take into account the entire range of operating temperatures of the tank car.

Safety Recommendation R-04-7, previously classified "Open—Unacceptable Response," is reclassified "Open—Acceptable Response" in the "Previous Safety Board Actions Regarding Tank Cars" section of this report.

To the Federal Railroad Administration:

R-05-16
Require railroads to implement operating measures, such as positioning tank cars toward the rear of trains and reducing speeds through populated areas, to minimize impact forces from accidents and reduce the vulnerability of tank cars transporting chlorine, anhydrous ammonia, and other liquefied gases designated as poisonous by inhalation.

Safety Recommendation R-05-16, previously classified "Open—Await Response," is reclassified "Open—Response Received" in the "Previous Safety Board Actions Regarding Tank Cars" section of this report.

To the Federal Railroad Administration:

R-05-17
Determine the most effective methods of providing emergency escape breathing apparatus for all crewmembers on freight trains carrying hazardous materials that would pose an inhalation hazard in the event of unintentional release, and then require railroads to provide these breathing apparatus to their crewmembers along with appropriate training.

Safety Recommendation R-05-17, previously classified "Open—Await Response," is reclassified "Open—Acceptable Response" in the "Train Crew Protection From Inhalation Hazards" section of this report.