​​On November 2, 2016, at 3:11 p.m. local time, CSX Transportation, Inc. reported a 68-gallon release of UN1987 denatured ethanol, a flammable Class 3 hazardous material, from cracks in the bottom of the shell of Archer Daniels Midland Company tank car ADMX 29899. The incident occurred in the CSX Transportation, Inc. rail yard located in Fredericksburg, Virginia. ADMX 29899 was the sixth tank car in train D79402, consisting of a buffer car loaded with steel and seven tank cars fully loaded with denatured ethanol. Due to the release and the resulting emergency rail traffic, other rail traffic on adjacent main tracks was significantly slowed, causing passenger train delays during peak traffic hours. The incident location was bordered by commercial businesses and residential neighborhoods. Weather at the time of the incident was sunny, and the temperature was 79℉.1

At 3:12 p.m., the Fredericksburg Fire Department dispatched to the incident scene and discovered ethanol leaking from the bottom of the tank car. The fire department noted that leaking ethanol was spilling onto ballast on the right of way, but the unseasonably warm weather accelerated its evaporation. By 3:45 p.m., a railroad emergency response contractor arrived on site and collected the leaking ethanol in an open container and moved the tank car to an adjacent track where the product could be transferred to another tank car. Crews completed the transfer by 3:15 a.m. on November 3.

We determined that the probable cause of the November 2, 2016, release of denatured ethanol from Archer Daniels Midland Company tank car ADMX 29899 was undetected cracks that resulted from overspeed high-energy coupling events, which caused tank shell deformation that led to the initiation of two fatigue cracks at the terminations of the cradle pad fillet welds.​

​We made a recommendation to the Federal Railroad Administration and the Pipeline and Hazardous Materials Safety Administration.