Hazardous materials car placement in a train consist. Volume 1. Review and analysis. Final report, 18 Feb-17 Nov 88

In response to major derailments involving hazardous materials cars, the Federal Railroad Administration (FRA) initiated the review of the consequences of hazardous materials car placement in a train consist. The review and analysis consisted of six task items: (1) review of accident trends and regulations, (2) an analysis of hazardous materials compatibility, (3) railroad operational constraints, (4) a cost/benefit analysis, (5) recommendations, and (6) preparation of a final report. A review of the 1982-1985 Railroad Accident/Icident Reporting System (RAIRS) data showed the rear quarter to be statistically the 'safest' location in a mainline freight train. Also, the top 101 hazardous commodities (by volume movement) plus fuming nitric acid were analyzed for chemical incompatibility, a total of 5,151 binary combinations. Consequence-based and risk-based rankings were established. Calculations established a post-derailment separation distance of 40 meters minimum to prevent mixing of incompatible chemicals. It was noted that mixing of hazmat materials was not cited in any NTSB accident report as a specific problem.