On March 10, 2017, about 12:50 a.m., central standard time, eastbound Union Pacific Railroad (UP) unit ethanol train, UEGKOT-09, with 3 locomotives, 98 loaded tank cars, and 2 buffer cars filled with sand derailed near milepost (MP) 56.8 at a timber railroad bridge on the Estherville Subdivision, near Graettinger, Iowa. Twenty loaded tank cars in positions 21 through 40 derailed. Fourteen of the derailed tank cars released about 322,000 gallons of undenatured ethanol, fueling a postaccident fire. The accident occurred near Jack Creek, a tributary of the Des Moines River. There were no injuries and three nearby homes were evacuated. About 400 feet of railroad track and a 152-foot railroad bridge were destroyed in the accident. UP estimated damages at $4 million. At the time of the accident, the wind was from the northwest at 17 mph gusting to 30 mph, visibility was 10 miles, and the temperature was 10°F. Figure 1 shows an aerial view of the accident.
We determined that the probable cause of the derailment was a broken rail that occurred as the train was traveling over the west approach of the Jack Creek Bridge resulting from Union Pacific Railroad’s inadequate track maintenance and inspection program and the Federal Railroad Administration’s inadequate oversight of the application of federal track safety standards. Contributing to the consequences of this accident was the continued use of US Department of Transportation Specification-111 tank cars.
We made new recommendations to the Federal Railroad Administration, the Pipeline and Hazardous Materials Safety Administration and to Union Pacific Railroad and reiterated a recommendation to the Pipeline and Hazardous Materials Safety Administration.
