Railroad Tank Cars
Tank cars are common, representing about one out of every seven rail cars. Over the years, industry and government have worked together to enhance both the physical tank car and the environment in which it operates. Following several incidents involving tank cars, however, the National Transportation Safety Board raised concerns about the adequacy of this process for protecting public safety.
About half of the nation’s roughly 200,000 railroad tank cars carry materials regulated by the U.S. Department of Transportation (USDOT) because they are flammable, corrosive, poisonous, or otherwise hazardous. In 1990, Congress directed USDOT to arrange for a study of the railroad tank car design process, including initial design, subsequent performance evaluation, and the means by which government and industry oversee and improve tank car design.
Design standards for tank cars are established by the Tank Car Committee of the Association of American Railroads, which consists of technical representatives from railroads, shippers, and tank car builders. Many of these design standards were adopted as requirements by federal regulations. In cases in which the standards are general in nature, USDOT relies on the Tank Car Committee to establish detailed design standards and review individual design drawings to ensure that they meet the underlying USDOT criteria.
The TRB committee that studied tank car safety found that the safety record of tank cars carrying hazardous materials is good and that severe incidents are rare and likely to remain so in the future (Special Report 243: Ensuring Railroad Tank Car Safety; TRB 1994). The committee also concluded that the government–industry design process is fundamentally sound. However, the committee recommended several modifications aimed primarily at ensuring that safety decisions are well supported and guided by long-range safety goals and strategies.