Review - ChemLock Exercises – Vehicle-Borne IED

 

NOTE: This is part of a series of blog posts looking at various CISA Tabletop Exercises Packages (CTEP) offered to chemical facility managers by the new CISA ChemLock program, a voluntary chemical security program run by the Office of Chemical Security (the CFATS folks). CTEP administrative documents can be found here. The scenario manuals can be found here. Earlier posts in the series include:

Overview,

Chemical Sector IED (short version), and

Chemical Sector Active Shooter (short version)

The Situation Manual for this vehicle-borne improvised-explosive (VBIED) exercise bills it as a review of “emergency preparedness plans and response procedures for an attack at a chemical sector facility.” It follows the same format as the two earlier exercises that I have discussed in some detail in the IED exercise post. Using the same format will make it easier for facilities to run subsequent exercises as they will already be familiar with the exercise processes.

The scenario for this module starts with a missing vehicle on the day before the exercise. On the day of the exercise a truck approaching the loading dock at the facility crashes into the dock and explodes. The provided discussion questions address:

• Plans that are in place to prevent or deter an attack at your facility,

• How security and personnel are trained,

• Standard operating procedures (SOPs) for incident response roles and responsibilities for staff,

• Assets onsite to immediately respond to an incident,

• Evacuation procedures for an incident of this type,

• Notification methods facility uses to send alert information,

• Incident command processes,

• Mutual aid agreements in place with other organizations,

• Notification of state or federal agencies of the incident,

• Law enforcement conduct of the response and address the threat,

• Medical response,

Commentary

While this is billed as a ‘Chemical Sector’ exercise, there is nothing in the scenario or discussion questions that would apply specifically to a chemical facility. The scenario could be applied to any manufacturing facility or warehouse in the country. There are no mentions of chemicals or chemical consequences in any of the discussion questions. This does not reduce the usefulness of the exercise, as the response discussion questions do identify areas of concern at chemical facilities, they just do not address the unique problems associated with a VBIED attack on a chemical facility.

For more details about the exercise, see my article at CFSN Detailed Analysis - https://patrickcoyle.substack.com/p/chemlock-exercises-ca9 - subscription required.

Flammable Gas Tanker Explosion

This is an interesting film from a local TV station (Fox8.com) 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……

Protection Against Explosions

Earlier this week I was asked by a long time reader if I could discuss ways to protect critical assets from an attack by a vehicle borne improvised explosive device. The facility at which he worked was trying to figure out what they could do to address this particular attack scenario. As always I am more than happy to express my thoughts on security related topics.

Standard caveat; I am not an engineer; I am a chemist by schooling. I do have some experience with explosives from the Army, but I am not an explosives expert and I have never detonated anything as large as a VBIED (if someone wants to let me push the plunger on one in a controlled test, I will certainly be there). Finally, before you actually install some protective device make sure that you are dealing with an engineering firm that has some experience in the field.

Prevent Detonation

The most obvious protective technique is the prevention of the detonation of the explosive device. While most of the responsibility for this lies with the intelligence and law enforcement people, the facility does have some basic techniques that they can employ to aid in the effort. The most obvious is the employment of an active counter-surveillance program. Any effective terrorist attack is going to be preceded by a variety of surveillance efforts.

The earlier efforts may be harder to detect, but as attack planning advances the terrorists will have to acquire more detailed information about facility security procedures. Facility employees and security personnel should always be on the watch for suspicious personnel hanging around the facility. The facility counter-surveillance plan should include an educational component to make personnel aware of the potential threat and their responsibility to be aware of what goes on around the facility. There needs to be a clear reporting procedure and the reports need to be promptly forwarded to local law enforcement for follow-up investigation.

Standoff 

The closer you can get an explosion to your target the more effect it will have. Conversely the further you can keep the explosion away from critical areas of the facility the less effect it will have. For a standard, non-focused explosion the force of the explosion should falloff as a square of the distance from the explosion. This means that even a small increase in the distance from the explosion can have a significant effect in force reduction.

Of course, the size of the explosion has an effect on the distance as well. I mean if you have a dry-box trailer packed with 40,000 lbs of commercial grade explosives the standoff distance will have to be much larger than if you have 500 lbs of homemade explosives in a panel van. So, to determine how far you have to keep the VBIED away from the potential target, you have to know how large a VBIED the terrorists will use against that target.

Obviously the terrorists are not going to tell you how large a VBIED they are going to use. So you have to guess; hopefully an educated guess, but a guess none the less. The guess should be based upon the potential risk; I would expect that a Tier 1 facility should expect a bigger VBIED than would probably be used against it than against a Tier 4 facility.

Don’t expect me to tell you what size to use; I just don’t have enough information to make even a lucky guess. Hopefully your security consultant will be able to provide a rationale for what ever size you pick. Once you have established your planning VBIED size you should be able to calculate (well the experts should be able to calculate, I haven’t seen the formulas) how far you have to keep the VBIED away from the target to have a reasonable chance of surviving without catastrophic damage.

If you want to keep your consultant on his toes, ask about max pressure and impulse effects. But, remember, you are going to need an expert. Anyone that tells you that there is a reasonable distance at which no damage will occur is either exaggerating or doesn’t understand explosions (a mile away from a 500 lb VBIED I would feel comfortable predicting little or no damage). With a VBIED attack if you can avoid catastrophic damage (ie: a quick, total drainage of a release-toxic COI from a large tank) you have achieved a reasonably successful defense. Your release mitigation techniques should be able to handle the results of non-catastrophic damage.

Blast protection The last type of protection is the one that probably requires the most expertise, physical blast protection. This can either be some sort of hardening of the target so that the blast will not affect it, or putting some sort of barrier between the potential blast and the target. Both require some special engineering skills and experience to properly design.

Once again, the size of the VBIED is a key design variable. If you dramatically underestimate the size of the device your blast barrier will become flying fragments that will contribute to the destruction of your target. One design element that needs to be considered is ‘line-of-sight’. Over longer ranges flying stuff from an explosion follow what is called a ‘ballistic arc’; the pieces fly up and out then fall to earth along an arc. The closer the initial trajectory is to 45° the further the projectile will fly.

At distances where blast effects predominate, however, the blast and projectiles are flying in essentially straight lines. Thus, any barrier must block the line of sight from the blast to the target. But, don’t forget to harden the top of the target to protect against falling debris.

Combination Plate The most effective VBIED protection scheme will utilize all three protective elements. Preventing detonation is, in my book, the most important element of the program. The lack of an explosion is the best protection. Remember, that the larger the VBIED, the more likely that there will be extensive pre-operational surveillance.

Putting together a large VBIED takes a lot of resources so the terrorists will do what ever is necessary to optimize their chance of a successful deployment; this means more surveillance. The last two, standoff and blast protection both require the services of someone who understands blast effects and blast protection engineering for optimal results. If you cut corners here you had better hope that your prevention program is very effective. A poorly designed protective program may actually increase the risk of a successful VBIED attack.

Special NOTE: Since this is a rather specialized field of study and application, I would certainly like to hear from practioners in the field. Discussion of the blast effect protection techniques would be particularly instructive.

Vehicle Barriers and VBIEDs

There is an interesting article over on SecurityManagement.com about choosing the right antiterrorism vehicle barriers. The article includes a link to a .PDF table showing a general comparison of the characteristics of different types of vehicle barriers. Both the article and the table should be valuable references for high-risk chemical facilities considering the use of vehicle barriers for their Site Security Plan.

The article is targeted at audiences looking to use vehicle barriers to prevent terrorist attacks on buildings using vehicle borne improvised explosive devices (VBIED). Since the targets discussed here are public buildings housing offices or apartments, the discussion of the blast analysis of a target structure is not really applicable to attacks on chemical facilities.

VBIED Targets 

While there might be some reason that a terrorist might want to conduct a VBIED attack on the office complex at a chemical facility, that is not the type target that most VBIED attacks will be pointed at in the event of an attack on a high-risk chemical facility. The most likely target of such an attack would be storage containers of toxic, flammable or explosive release chemicals of interest (COI). Since a VBIED attack is a high-cost attack strategy, it is most likely to be pointed at the highest value target, the storage container(s) with the highest off-site consequence.

If the facility had a large acrolein storage tank and a warehouse containing a small number of acrolein drums, the storage tank would certainly be a more likely VBIED target. A facility with similar sized tanks of allyl alcohol and allylamine would probably decide that the allyl alcohol tank would be a more valuable terrorist target because it is a toxic release (vs a flammable release) COI; and it would have more of an immediate off-site consequence if released into the environment.

That value calculus can be deceptive in some cases. If a facility has a high-pressure containment vessel like a chlorine tank, it may be easier for a terrorist to attack a nearby flammable release COI storage tank. The resulting fire, if close enough to the chlorine tank, could cause a catastrophic rupture of that tank through weakening the thick metal walls of the tank and increasing the pressure inside of the tank above the design limits.

Storage Tank Damage 

The SecurityManagement.com article has a pretty good discussion of the graduations of the types of damages that a VBIED can inflict on a target building. Understanding these damage levels is important in crafting an anti-VBIED barrier plan. Ideally a security planner would like to prevent any damage, but a realistic assessment might be made that a few broken windows from the overpressure effect might be an acceptable level of damage.

This would affect the required standoff distance between the barriers and the building. A similar decision tool is required for chemical storage tanks. The damage assessment criteria for storage tanks should be based on the resulting release rate of the chemical the chemical of interest. The higher the release rate the more likely there would be an adverse off-site impact from the release. The comparable structural damage limit states for storage might be categorized (lowest to highest risk) as:

Damage to associated piping; Limited damage to gaskets, seals or flanges on the tank proper; Small punctures (<1 in="" major="" punctures="" tank="" the="" walls="">1”) in the tank walls; or Catastrophic failure of the storage tank.

The overpressure effects required to produce the damage are going to depend in large part on the type of construction of the storage container. High-pressure systems will require higher levels of overpressure to sustain similar levels of damage. I have not seen any specific figures for the overpressure required to sustain these levels of damage, but I suspect that they would be available from the Center for Chemical Process Safety or one of the engineering associations.

Size of VBIED 

One important factor in determining the placement of vehicle barriers that is kind of glossed over in this article is the size of the explosive charge in the VBIED. This is a critical variable in determining the overpressure produced by detonation. A 40,000 lb ammonium nitrate VBIED will produce catastrophic storage tank failure over a much larger area than a 500 lb VBIED. It would not be reasonable to assume that a terrorist team would use a 40,000 lb VBIED to attack a 5,000 gallon flammable release storage tank. The VBIED detonation would be more dangerous than the subsequent release.

Parking such a VBIED outside of the security perimeter would have more of an off-site consequence and would be a less risky operation. The security system design team is going to have to determine what is a reasonable sized VBIED that they could expect to face in a serious attack on the facility. They will have to take into account the fact that a larger VBIED is much more costly to a terrorist organization (from both a materials and operational perspective) than a smaller VBIED.

The design team is going to have to weigh the cost of VBIED against the utility of the facility as a target. A large chlorine storage facility in a major urban area will have to design for a larger VBIED than a similar sized facility in a rural setting. Unless DHS decides to get involved in dictating VBIED sizes for the design basis for facility security systems (and an argument could be made for a Tier ranking based size standard), the VBIED size determination will be a facility security management decision. The basis for the VBIED size used in the security system design should be explicitly spelled out in the design documents.

Improvised Explosive Awareness Training

Last week I came across a notice on the American Chemistry Council’s Responsible Care® website announcing an improvised explosive awareness training course being put on by the Chemical Branch of the DHS Sector Specific Agency. The notice announced a January class in Houston, TX with later classes in Los Angeles, Dover, Newark, Detroit, and Chicago (exact dates yet to be announced). It also provided a point of contact at DHS for further information, whom I have contacted. Nohemi Zerbi (Nohemi.zerbi@dhs.gov, (703) 235 – 2871) was kind enough to provide me with a flyer for the Houston class. To register for the free class (first come, first serve) you just need to contact Nohemi. Registration is limited by the number of seats available at the venue. In any case, registration closes on December 23, 2008. This is a day long course (8:00 am to 4:30 pm). It will address the basics of both improvised explosive devices (IED’s) and vehicle borne IED’s (VBIED’s) with a view to reducing vulnerabilities and providing “information sharing resources to improve preparedness”. It looks like the target audience is probably corporate security types or possibly Facility Security Managers. I am trying to get some further information on the background of the presenters and some more information about the level of detail that will be provided. If and when I get additional information, I will let you know.