Technical Reports

Survivability of Railroad Tank Car Top Fittings in Rollover Scenario Derailments

  • 01
  • Dec
  • 2005
AUTHOR: Robert Trent, Anand Prabhakaran, Vinaya Sharma
OFFICE: RPD
REPORT NUMBER: DOT/FRA/ORD-06/11
SUBJECT: Hazardous Materials
KEYWORDS: Tank car, rollover, fittings, protection, tank car safety, dynamic simulation
ABSTRACT: This project examined the structural susceptibility of tank car fittings during derailments. The report identified non-pressure cars as being the most susceptible to derailment damage. A DOT111A100W1 fuel service car was selected for analysis. Two derailment scenarios were modeled. The first simulated a severe derailment, were the tank car body is thrown off its trucks with significant momentum. The second simulated a nominal rollover, which is more representative of a low speed yard derailment. Simulation results indicated failure of multiple components in the fittings structure for both scenarios, implying that conventional non-pressure car top fittings are likely to suffer damage and cause lading release under most derailment scenarios. Subsequently, the report developed two concepts of protective structure. The first (Concept 1) is designed to protect the fittings with a bolt-on sleeve structure. The second concept starts with Concept 1 and adds elements to strengthen the fittings-to-tank shell interface. Simulations indicate that both concepts survive the nominal rollover and neither of them survive the severe impact, with Concept 2 faring better than Concept 1 in both scenarios. Concepts similar to the ones developed in this report could improve the structural performance of top fittings in many cases.

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