The National Transportation Safety Board (NTSB) issued four urgent recommendations calling for construction of more robust tank cars to carry crude oil, ethanol, and other highly combustible liquids via rail.
The recommendations were derived from the independent federal agency’s examination of damaged tank cars following a Feb. 16 derailment of a CSX Transportation crude oil unit train in Mount Carbon, W.Va., as well as a review of data collected from accidents in Gogama, Ont., on Feb. 14; Galena, Ill., on Mar. 5; and Gogama, Ont., on Mar. 7.
“In these four accidents, investigators have found consistent 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,” NTSB Chairman Christopher A. Hart said in his Apr. 3 letter to Timothy P. Butters, US Pipeline and Hazardous Materials Safety Administration acting administrator.
“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 over-pressurization,” Hart said.
In its recommendations, NTSB called 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.
“We can’t wait a decade for safer rail cars,” Hart said as NTSB publicly released its recommendations on Apr. 6. “Crude oil rail traffic is increasing exponentially.”
NTSB said the current fleet of DOT-111 tank cars ruptures too quickly when exposed to a pool fire caused by a derailment or other accident with resulting spillage and ignition. It said its investigations of the four recent accidents showed performance of the rail industry’s enhanced rail car, the CPC-1232, is not satisfactory under these conditions.
The board also called for swift changes of the fleet, and for intermediate deadlines and transparent reporting to ensure the US tank car fleet is being upgraded as quickly as possible.
Others have called for treatment of crude to make it less volatile prior to loading onto tank cars as an alternative to replacing tank cars which potentially could be expensive. But a US Department of Energy report found gaps in important crude oil characterization data, uncertainty about how to best sample and analyze crude to ensure its properties are determined accurately, and deficiencies in understanding how a crude’s properties affect its potential to accidentally ignite, combust, and explode (OGJ Online, Mar. 25, 2015).
An American Petroleum Institute official said the report shows the need to focus more on preventing train derailments as part of a holistic approach to making shipping crude by rail safer.
“This report raises puzzling questions about Acting Federal Railroad Administrator Sarah Feinberg’s suggestion that nothing more can be done to prevent derailments,” API Midstream Director Robin Rorick said. “We can and must do more to prevent derailments as part of a comprehensive approach to safety.”
“It’s disappointing that API continues to look for reasons not to engage in improving safety,” DOT spokeswoman Suzanne Emmerling responded. “As Administrator Feinberg has said time and time again, while the rail industry has taken many steps to improve safety, we will always demand more and expect more from them. We continue to hope the energy industry will join in those efforts.”
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