There is an interesting discussion going on over on the Hazardous Materials Emergency Response (group membership required) group on LinkedIn about one of the byproducts of the current crude oil glut. As more expensive crude oil production sites are closed off due to the low market price of crude oil, there will be a reduction in the amount of crude oil transported in the US and Canada by railroad. One would like to think that this will lead to an increasing number of the most hazardous DOT 111 railcars being taken out of crude oil service.
Bill Barnholt, Cobra Hazmat/Safety Consulting & Training, writes in his discussion that:
“This means that there's going to be hundreds of (hopefully residue not loaded) tank cars being stored in areas that aren't used to having them around. This also increases the possibility of sabotage of the tank cars being stored. This will make the need for Emergency Responders even greater.”
Now this is not really an unusual occurrence. There are certain types of railcars that are periodically idled. The use of grain transport hopper cars, for instance, drops off dramatically after the harvest has been transported to market. The cars that are not actively in use are parked on some sort of non-active track until they are needed again.
The problem with these crude oil railcars, however, is that they may contain significant amounts of crude oil residue. While there certainly isn’t enough in a rail car to cause the sorts of fires that we have seen in the last year or so, there certainly is enough flammable vapors in these cars to cause a sizeable explosion if enough oxygen is present and there were some sort of ignition source.
I know that sounds dangers but there are two important ‘ifs’ in that statement. First enough oxygen must be present. We would expect these cars to be closed and, unless someone deliberately introduced oxygen into them, it is highly unlikely that there would be enough oxygen to support combustion inside the car. Second you would need a heat source (fire, electrical spark, etc) inside the car to provide an ignition source.
The very low probability problem could be eliminated by washing out the crude oil residues out of the railcars. Anyone that has ever cleaned a greasy auto part will have some inkling of the problems that are involved in this process. Needless to say this is not something that can be done safely or environmentally soundly just anywhere. Special facilities are required, the wash residue is typically a hazardous waste, and everything about this is quite expensive.
To the best of my knowledge there is no regulatory program that would require the owners of these cars to have them cleaned prior to parking them on a siding somewhere. Even more scary is the fact that there are no regulations that govern the security of these railcars that contain only residues. And there are certainly no rules governing where they can be parked.
Theoretically it would be fairly simple to turn these residue containing tank cars into rather impressive bombs. Some of the equipment would be a tad bit heavy for transporting by hand and it would take a little bit of knowledge about rail car fittings, but with the proper equipment and about 30 minutes access to the railcar a vapor phase explosion could be produced.
The effects of the explosion would be dependent on a number of factors, most of which would not be readily discernable before the attacker opened the railcar. I would expect, however, that if enough crude oil residues were present, it would be possible to produce a large enough explosion to damage nearby structures, kill people, and attract national news attention. In other words, it would be a successful terrorist attack if it took place near inhabited areas.
It is certainly too late to start any legislative or regulatory action to address the immediate issue. Local police departments should probably plan on actively patrolling these parking areas and all first responders should have a good idea where these railcars are parked in and near communities.
Other than that the best we can do is to continue to hope that the various wackos that wish to create death and destruction in support of whatever cause ignites their anger continue to lack the creativity and knowledge necessary to execute these types of attacks.