A broken rail, inadequate track maintenance and inspection, and inadequate federal oversight led to the March 10, 2017, derailment of a Union Pacific Railroad ethanol train near Graettinger, Iowa, according to a National Transportation Safety Board (NTSB) report released Tuesday. (NTSB photo shown above.)

The agency also said in its report the continued use of US Department of Transportation Specification 111 tank rail tank cars in ethanol service, instead of the more robust DOT-117 tank cars, contributed to the severity of the accident in which about 322,000 gallons of undenatured ethanol was released, fueling a post-accident fire that burned for more than 36 hours. No one was injured in the accident that forced the evacuation of three nearby homes and caused an estimated $4 million in damage including the destruction of 400-feet of railroad track and a 152-foot railroad bridge.

The train consisted of three locomotives, 98 loaded tank cars and two buffer cars filled with sand. Twenty of the 98 loaded tank cars derailed, 14 of the 20 derailed tank cars released their cargo of ethanol. Of these 14, 10 were breached from mechanical damage, four tank cars with shell damage released ethanol from bottom outlets or top fittings and thermal damage. The report states the use of DOT-117 cars, instead of the DOT-111 tank rail cars involved in the accident, would have mitigated or prevented the release of ethanol most of the derailed cars. 

NTSB investigators concluded the Union Pacific Railroad was not maintaining the track structure on the Estherville Subdivision (a region of rail that includes the accident location) in accordance with Federal Railroad Administration minimum track safety standards or its own track maintenance standards. The NTSB also determined FRA inspectors did not report all defective crosstie conditions observed in the Estherville Subdivision. Additionally, investigators said in the report FRA inspectors were not using all available enforcement options to gain Union Pacific compliance with minimum track safety standards. 

Impaired, distracted driving not factors

The report states alcohol or drug use, and cell phone use were not factors in the accident nor was the mechanical condition of the train, the performance of the train crew or the emergency response.

The NTSB issued three new safety recommendations and reiterated one safety recommendation. The recommendations, issued to the FRA, the Pipeline and Hazardous Materials Safety Administration and Union Pacific, address training on safety standards and available enforcement options for federal track inspectors, the need for research to determine if safety would be improved by transporting ethanol in an undenatured state, and the need for Union Pacific to reexamine track maintenance and inspection program standards on all routed carrying high hazardous flammable materials.

The abstract of the final report for the investigation may be found online at http://go.usa.gov/xPm73. The final report will publish on the NTSB’s website within a few weeks.