Safeguarding Building Perimeters For Bomb Attacks

May 12th, 2010 | Security Articles & Tips

Minimizing The Impact

Managing this kind of security threat is surprisingly easy. According to civil engineer Joyce Engebresten (Himan Consulting Engineers, Inc., San Francisco), it’s all about distance. “Keeping an aggressor away from the building is the most effective strategy”, Ms. Engebresten explained to a group of security professionals in San Antonio, Texas.

A bomb blast’s shockwaves generate pressure on a structure that creates the damage, and proximity of the bomb to the building influences this pressure significantly. For example, a car bomb at 25 feet will put 40% less pressure on a building than a bomb just a few feet closer. The further away you can keep a vehicle significantly limits the damage a car bomb will do to your facility. Maximizing the standoff is the most efficient deterrence approach. The greater the standoff, the less hardening your property needs.

Clearly, effective standoff is simple to achieve if it’s a consideration before construction rather than as a retrofit. Individuals who are responsible for security need input into new projects, specifically by making sure that the building designers incorporate security into their design. The security design they propose should be in line with the General Services Administration’s Security Design Criteria. These buildings standards were implemented for all federal buildings shortly after the Oklahoma City bombing.

Another essential facet of protecting the building perimeter is ensuring the reliability of bollards and other barriers. After all, your company is far more likely to install bollards to keep vehicles at a distance that it is to put in a fountain or re-grade the landscape. Your company will need to decide if the primary purposes of the bollards and/or barriers are for discouraging traffic or to prevent a car bomb attack. This is extremely important because most bollards or planter boxes are not capable of withstanding vehicle ramming.

If you are using planters, they should be slightly buried or reinforced with rebar to affix them more firmly in place so that they can withstand the kinetic energy of a moving truck. Bollards must extend across the entire perimeter so that drivers cannot get around them.

The use of Jersey barriers in combination with other barriers will help protect your facility should a small car bomb go off adjacent to one, but if the bomb is large, these barriers will fragment and possibly do more harm than good.

Whether or not you need to worry about a terrorist bombing attack depends on your company profile. Companies that are solely domestic based typically have a minimal threat. However, if a terrorist act is a concern, then car bombs need to be a focal point of your perimeter security because bombings are terrorists favorite attack method.

Could your property be the target of a terrorist bomb attack? Conducting a risk assessment will help you determine the feasibility of such vulnerabilities (Refer to sidebar Determine Your Perimeter Protection Response).

The aforementioned guidelines will help you safeguard the perimeter against a vehicle attack; however, there are other areas that you must address in order to completely minimize the impact from a vehicle bomb. The strategies and information contained on the following pages will help you protect the building and mitigate the effects of vehicle bomb.

Determine Your Perimeter Protection Response

Consider the following questions when assessing the risk:

  • Who or What is the threat?
  • Is a bomb a possible choice of weapon?
  • What are the most likely scenarios or tactics for introducing a bomb in or near your buildings?

If you are a risk for bomb attack, consider the consequences of taking action:

  • What resources, including technologies, are available to respond to the threat?
  • What are the odds of applying these techniques?
  • What will the building tenants, employees, and occupants tolerate in the way of inconvenience or added expense for security measures?

*Source: Protecting Buildings from Bomb Damage: Transfer of Blast-Effect Mitigation Technologies from Military to Civilian Applications, National Academy of Sciences

Strategies for Protecting Your Building Perimeter

I. The Perimeter

1. Reduce vehicular approach speed by adding bumps and curves in the road. Control vehicular access with vehicle barriers, traps, or hydraulic barricades.

2. Use barriers, such as courtyards, plazas, landscaping, perimeter bollards or planters, fountains, reflecting ponds, and other features to insure that a vehicle armed with a bomb will not be able to drive up next to the building and park.

3. Maintain a clear zone between surface parking and building (100 feet or more, if possible) and use barriers, planters, or knee walls to protect the building from ramming.

4. Identify and, if necessary, search vehicles permitted to park beneath the building. In extreme cases, parking under the building should be severely restricted or banned.

5. Keep public underground parking away from critical building systems, backup generators, or gas meters.

6. Improve nighttime lighting as appropriate for the area and local ordinances.

7. Increase site surveillance and monitoring capability and/or patrols.

8. Use CCTV surveillance to monitor and record vehicle activity.

II. Building Exteriors & Grounds

1. Apply blast film to windows. This may be expensive but it can save lives, prevent injury, and protect against both equipment and document destruction in the event of a bomb blast targeting either your building or one up to five or more blocks away.

2. Secure and alarm windows and emergency egress doors accessible from ground level. Also secure the building from accessible roof levels and setbacks.

3. Check the location and design of air intake grilles for the possibility of inducing smoke or noxious gases.

4. Keep loading dock doors closed. Where this is not practical, control access from the dock area to freight elevators, fire stairs, and the building interior.

5. Locate garbage skips and compactors within the building perimeter or, if outside, well away from the exterior walls.

III. Building Entry

1. Separate employees with valid credentials from visitors, contractors, messengers, and delivery people.

2. Process employees with credentials automatically using credential-reading systems but those without building or corporate credentials need to have their identity and purpose for being in the building validated before you permit access.

3. Control and screen all delivery service. Consider a messenger drop-off center with a separate entry and use internally cleared and uniformed personnel to deliver packages. Employees receiving lunch deliveries that require payment should pay for and accept the delivery at ground level.

4. Use airport-type screening (walk-through metal detectors and package x-ray systems) for all seeking access to the building interior. In very high-security environments, use explosives-detection equipment for bags and people.

IV. Building Interior

1. Develop layers of security and place those assets at high risk within the innermost layers. For example, secure each floor at its elevator lobby and, fire codes permitting, fire stair doors and further secure sensitive operations within the floor.

2. Locate building occupants away from portions of the building with direct street frontage. Use such areas for non-vital equipment or storage.

3. Identify and secure those assets that might be high-profile targets or are most important to your business operations. Such assets might be executives, managers, HR personnel, receptionists, data centers, and voice and data cabling and equipment.

4. Remember rooftop assets such as wireless transmission equipment and emergency generators.

5. Locate shipping and receiving areas in remote areas of the facility.

6. Develop a contingency plan and test it regularly to deal with aftermath of likely attack scenarios.

*Source: International Association of Professional Security Consultants)