The National Transportation Safety Board issued four urgent recommendations calling for more robust and fire-resistant rail cars to be produced to safely carry flammable liquids such as crude oil and ethanol.
In its recommendations, the Board calls for an aggressive schedule of replacing or retrofitting the current rail car fleet with better thermal protection against heat from fires, such as through a ceramic thermal blanket, and increasing the capacity of pressure relief devices.
The Board said the current fleet of DOT-111 tank cars rupture too quickly when exposed to a pool fire caused by a derailment or other accident with resulting spillage and ignition. Based on a series of accidents the Board has investigated in recent months, performance of the industry’s enhanced rail car, the CPC-1232, is not satisfactory under these conditions.
|Evidence of shell bulging from overpressure, shell material thinning, and tank shell tears in the vapor space of bare steel CPC-1232 tank cars exposed to pool fire conditions in a recent accident. Source: NTSB. Click to enlarge.|
The NTSB concludes that the thermal performance and pressure relief capacity of bare steel tank cars that conform to current federal and industry requirements is insufficient to prevent tank failures from pool fire thermal exposure and the resulting overpressurization.—Letter from NTSB to Acting Administrator Timothy P. Butters of the Pipeline and Hazardous Materials Safety Administration
The Board also called for swiftness in changing the fleet and called for intermediate deadlines and transparent reporting to ensure the tank car fleet is being upgraded as quickly as possible.
The full recommendations are:
R-15-14. Require that all new and existing tank cars used to transport all Class 3 flammable liquids be equipped with thermal protection systems that meet or exceed the thermal performance standards outlined in Title 49 Code of Federal Regulations 179.18(a) and are appropriately qualified for the tank car configuration and the commodity transported.
R-15-15. In conjunction with thermal protection systems called for in safety recommendation R-15-14, require that all new and existing tank cars used to transport all Class 3 flammable liquids be equipped with appropriately sized pressure relief devices that allow the release of pressure under fire conditions to ensure thermal performance that meets or exceeds the requirements of Title 49 Code of Federal Regulations 179.18(a), and that minimizes the likelihood of energetic thermal ruptures.
R-15-16. Require an aggressive, intermediate progress milestone schedule, such as a 20% yearly completion metric over a 5-year implementation period, for the replacement or retrofitting of legacy DOT-111 and CPC-1232 tank cars to appropriate tank car performance standards, that includes equipping these tank cars with jackets, thermal protection, and appropriately sized pressure relief devices.
R-15-17. Establish a publicly available reporting mechanism that reports at least annually, progress on retrofitting and replacing tank cars subject to thermal protection system performance standards as recommended in safety recommendation R-15-16.