The derailment in East Palestine, OH, was a classic need for a Vent & Burn operation (as shown in the video). There was some indication that one or more of the Vinyl Chloride railcars had begun its polymerization reaction, which could result in catastrophic consequences for many people and property. This indication also eliminates the option of transferring the VCM to other containers. So the decision was made to perform the vent & burn, eliminating the uncontrolled catastrophic failure of the VCM railcar(s).
This exercise involves two charges being placed on the railcar(s): one creating a vent in the headspace and the other creating a larger opening at the lowest point on the car. The vent is blown first, seen as the gaseous vertical plume in the video, and then the second charge blows a hole in the bottom of the car for the liquid to drain out into an earthen dike constructed by responders. Inside the earthen dike, road flares or some other ignition source are placed to ignite the flammable gas, shown as the larger explosion in the video. I am not sure who performed this vent and burn, but it went off perfectly and did exactly what they hoped it would.
Vent and Burn is NOT some wild cowboy stunt; it is a very structured and calculated exercise, recognized as a last resort effort to control a potentially catastrophic event. As the FRA manual states…