Monday, August 27, 2012

Flammable Gas Tanker Explosion

This is an interesting film from a local TV station ( of a tanker of isobutane exploding on Interstate 10 in Baton Rouge, LA last week. The tanker was deliberately exploded by authorities after it was rear-ended in a freeway accident and its unloading line was damaged and leaking. There had been numerous attempts made to unload the damaged trailer, but they had been unsuccessful; leaving the authorities with no choice but to detonate the trailer in place.
Explosion Video

Planned Detonation

Needless to say the freeway was blocked off and local homes and businesses were evacuated as a precaution well before the detonation. Fire crews were in place and the plan for fighting the fire was worked out in advance. Even with all of the precautions that were taken, it took fire fighters almost two hours to put the fire out.

It looks to me that the explosives that were used were emplaced to direct the main force of the explosion upwards. This would have been done to minimize the potential for flames to spread beyond the confines of the freeway. The folks that did this really knew what they were doing.

Security Lessons

This video should be viewed by all security managers for chemical facilities that receive flammable liquids and flammable gasses. It gives a very good idea of the extent of the fireball from a tank wagon that has been turned into a vehicle borne improvised explosive device (VBIED). Security processes, procedures and protective measures need to take into account the extent of fire ball seen in this video. It should also take into account that it took fire department teams two hours to control the flames when they had equipment on site ready and prepared to act.

Tank Wagons as Terror Weapons

The next security issue takes just a little more imagination. Instead of this occurring on a closed Interstate with the surrounding buildings evacuated for a safe distance in advance, watch the video and try to imagine the freeway being packed with rush hour traffic. Imagine that fireball covering the adjacent lanes and engulfing every car around the truck in both directions to the extent of the fireball. Then imagine the effects of the secondary fires and explosions as those cars burst into flames.

Then imagine the traffic behind those cars plowing into the fire ball and contributing their own impressive fireworks to the conflagration. The cars that are able to stop before running into the actual flames may still feel the effects of the blast over pressure and flash burns. Some of those cars will burst into flames because the high temperature of the fire will heat combustible and flammable materials to their autoignition temperatures.

Most of the vehicles will be able to stop beyond the direct effects of the fires and explosions, but they will face hazards of their own. In any freeway accident at rush hour there will be multiple collisions because drivers were following too close, driving too fast, were distracted by other things going on, or, in this case in particular, were stunned by the visual effects to their front. The freeway will quickly become a parking lot.

If the person with the detonator switch in hand was sufficiently devious, the tanker would have been underneath an overpass when the contents were detonated. While the overpass structure would have protected most of the traffic above from the direct effects of the blast, the accidents and the casualties would be significant.

More importantly, the fire could weaken the structure of the overpass enough to make it unsafe for traffic for weeks and months to come. The potential damage to the roadway underneath and around the truck might also prevent its use for extended periods of time. The immediate effects of the attack would affect the community for months; quite a successful terrorist attack.

HAZMAT Trucking Security Rules

TSA does not currently have any regulatory power over the security of the trucking industry. They do have a few unofficial programs in place to look at corporate security planning and risk assessment, but no authority to require even the basic security measures.

The Pipeline and Hazardous Material Safety Administration (PHMSA) does have a regulatory program (49 CFR §172.800) that addresses security for certain hazardous materials shipped by truck. The program is vague with little in the way of descriptions of what types of risk need to be addressed or what types of security measures might be required.

Section 172.802 describes the security plan this way:

“The security plan must include an assessment of transportation security risks for shipments of the hazardous materials listed in § 172.800, including site-specific or location-specific risks associated with facilities at which the hazardous materials listed in § 172.800 are prepared for transportation, stored, or unloaded incidental to movement, and appropriate measures to address the assessed risks. Specific measures put into place by the plan may vary commensurate with the level of threat at a particular time.”

It does require that the plan address (in the most general terms) the following topics:

• Personnel security {§172.802(a)(1)};

• Unauthorized access {§172.802(a)(2)}; and

• En route security {§172.802(a)(3)}.

Carriers are required to have copies of these security plans on file at their corporate headquarters where they may be inspected by PHMSA inspectors or their State counterparts. Since those inspectors are safety inspectors it is hardly likely that they have received any significant security training to equip them to provide a knowledgeable review of the provisions. One would assume that they might actually ask to see these plans on occasion and would be satisfied if they were present.

The question becomes, is this adequate to prevent attacks like the one I described above? The answer is left as an exercise for the student……

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