Technical Reports

Hazardous Materials Transportation in Tank Cars: Analysis of Risks- Part I

  • 15
  • May
  • 1993
AUTHOR: Federal Railroad Administration
SUBJECT: Hazardous Materials
KEYWORDS: tank cars; risk; population exposure; probability; poison by inhalation materials; accidents; consequence
ABSTRACT: This report covers the development of a methodology to evaluate the potential national public risk arising from the transportation of hazardous materials in tank cars on US railroads. The analysis is intended to assess the relative changes in the overall risk when (structural) safety devices are provided on tank cars and the relative risks of transporting different chemicals in a specified DOT class tank car. The risk model developed takes into account the characteristics of tank cars, the puncture probability, properties of the hazardous material released and its behavior in the environment, occurrence of the accident in different population density areas under different types of weather conditions at the time of the accident, etc. Toxicity, fire and explosion behavior of the chemicals have been considered. The focus of application of the model has been to the transportation of the poison-by-inhalation (PIH) and flammable materials. The results of the risk assessment model have been presented as a matrix of frequency and consequence classes indicated by MIL standard 882 B. It is seen that the transportation of PIH in highly protected, higher strength tank cars, such as the DOT 105 provides about an order of magnitude reduction in the overall public risk compared to the transportation of the same material DOT 111 A class tank car.