A Crash Course

A Crash Course

Creating a vehicular perimeter security system

A Crash Course Creating a vehicular perimeter security systemKeeping pedestrians safe, protecting structures from accidental or intentional automobile crashes and force protection—keeping employees and visitors from harm—have always been a concern. From pedestrian-filled farmers markets and universities to new and used car lots, a wide variety of agencies find peace of mind through the use of barriers, bollards, barricades and crash gates for vehicle-based physical access control at the perimeter.

Risk Assessment Starts with Physics 101

When evaluating the security risk for a given facility, particular attention must be paid to the weights and velocities of vehicles that would be used to attempt penetration into sensitive areas. A vehicle moving toward a barricade has a certain kinetic energy, the major measure of how much “hitting power” it possesses. Mathematically, kinetic energy is derived from the vehicle’s velocity and its weight (mass). On impact, some of this energy is converted to heat, sound and permanent deformation of the vehicle, so the barricade must absorb the remainder of this energy if the vehicle is to be stopped.

The amount of remaining energy varies depending on many factors, primarily the velocity of the vehicle at the moment of impact, as the amount of kinetic energy posed by a vehicle changes at the square of its velocity. For example, a vehicle moving at 50 mph has 25 times as much kinetic energy as it would at 10 mph. Thus, an armored car weighing 30 times as much as a Toyota Corolla and moving at 10 mph would have less hitting power than the Toyota moving at 60 mph.

Because of the relationship between velocity and total kinetic energy possessed by the vehicle, every effort must be made to force a vehicle to slow down before it reaches a barricade. The most frequently used technique is to require a sharp turn immediately in front of a barrier. When vehicle speed is reduced by 50 percent, its hitting power is reduced by four times; if the speed is reduced by two-thirds, the force of impact will be reduced nine times.

When designing a way to slow down a vehicle, precautions should be taken so that the attacking car cannot make a “corner-cutting shot” at a barricade. Often, only a light post defines a turning point and a speeding car can take it out, usually without hesitation. Therefore, knolls and other impediments should be considered. Failing to understand this and not using the proper equipment to counter a threat may lead to a false sense of security.

Overcoming Common Design Deficiencies

Today’s barriers and bollards are capable of stopping and destroying a truck weighing up to 65,000 pounds and traveling at 50 mph. Such barricades can be raised or lowered at will to stop traffic or let it through. In an emergency, the thick steel plates, or bollards, pop out of the ground within 1.5 seconds.

When integrated properly into a total system including fences, lights, alarms, gates and other security components, vehicle barriers are a key measure in preventing threats to sensitive resources. It’s important to consider supplemental gate and fencing reinforcements that may be needed to optimize vehicle barrier effectiveness.

In designing a barrier system, you must consider whether to use a passive or active system. Normally, an active system keeps the barrier in the active or up position, so it must be deactivated to permit access. Active systems are preferred to ones that must be activated to prevent access because they are more secure.

However, linear thinking won’t get you very far when planning a vehicular perimeter security system. Straight lines make for faster and easier approaches for vehicles, so it’s best to create curves on the access roads to your facility as a natural impediment to speeding cars or trucks.

Another common planning deficiency occurs when designers choose non-certified barriers or barricades. Certified equipment has been tested and proven to work under extreme conditions, giving planners the confidence they rely on. Without adequate testing, there is no assurance that the barrier will resist the threat. Testing is normally done by an independent testing company or government agency, such as the State Department or military. Comprehensive reports of test results are issued and are available from the testing agency or manufacturer. No area is more critical to the vehicle barrier selection process than testing.

One final area that should not be overlooked is aesthetics. With today’s smart designs, it is no longer necessary to choose between form and function; both can be achieved. Designers are creating secure environments with more compatible and aesthetically- pleasing architectural elements. If you visit Washington, D.C. today, for example, you’ll see landscaped islands at the north and south entrance drives which regulate vehicular access. If allowed to drive into the Capitol complex, you will cross over vehicle control barriers and bollards at the entrances. Indeed, all exits at the end of all drives are controlled with barriers, which pop from the ground when needed.

Similar barriers and bollards are found at refineries, distribution centers and headquarter offices of petrochemical and hydrocarbon companies all around the world.

Putting New Vehicular Threat Tactics on the Defensive

By their very nature, terrorist attacks are unpredictable, occurring as a surprise. Staying one step ahead by identifying vulnerable areas and securing them is critical to staving off vehicular attacks. That means being able to deploy security equipment in tough conditions at a moment’s notice. Fortunately such equipment now exists in the form of portable, towable and temporary barriers. These barriers can be deployed quickly and effectively, even in places where it’s impossible to excavate for a permanent foundation, such as the streets of Paris.

Terrorists typically don’t go where they see barricades, so placing them wherever possible attacks can happen reduces security risks dramatically. Temporary barriers can protect facilities while permanent ones are being built, and they’re even effective for the long-term where physical conditions preclude permanent solutions.

There are many types of available portable barriers and barricades:

Drop arm barrier: Able to be deployed or relocated for full manual or automatic operation within two hours, these quick deployment barriers will stop and destroy a 15,000-pound truck traveling at 30 mph in less than 20 feet. They secure an entrance roadway eight to 24 feet in width from vehicle attack.

Portable plate barricades: These provide security against vehicle-based terrorism or thefts for highcycle locations such as the entrances to large office facilities, government agencies and military bases. Able to be deployed in high-traffic locations for full manual or automatic operation within two hours, these quick-deployment, modular barricades feature a phalanx-type rising plate barrier, mounted within multiple inertial pods.

The plate barrier lies level to the ground to allow vehicles to pass and is raised or lowered into position using a hydraulic cylinder driven by a hydraulic power unit. The hydraulic pumping unit can be sized to provide pass-through rates suitable for most inspection and identification station requirements.

Towed portable crash barriers: Able to be deployed in 15 minutes, the newest portable, high-security, vehicle crash barriers can quickly protect facilities and people from vehicle attacks and accidents. These mobile crash barriers can be towed into position by a mediumsized pick-up truck or equivalent. This mobile barrier operates locally or remotely for guard protection.

Deployment, retrieval and operation are all hydraulic. These barriers stop and disable a 15,000-pound vehicle moving at 30 mph. These portable crash barriers were built for U.S. Federal government security specialists who wanted a system that could be rapidly deployed and then operated as a regular security gate or barrier system. Once positioned, the mobile barricade is separated from its transporter and lowered into position by means of a battery-operated hydraulic power system, which is then used to raise or lower the barrier for normal or emergency tasks.

Permanent Barriers and Barricades

From parking lot security to stopping vehicular access at refineries, there are a variety of suitable barricades available. Solutions include:

  • High security barriers are all crash rated in widths up to 288 inches and up to 38 inches high. Lowered to allow passage of authorized vehicles, these barriers are the first line of defense at critical facilities.
  • High-security, surface-mounted barricades allow quick installation into difficult locations such as parking structure ramps or areas with sub-surface drainage problems. These crash-rated barricades are lowered to allow passage of authorized vehicles and are available in widths up to 288 inches.
  • Very high security, shallow foundation barriers are available for advanced counter-terrorism applications in sub-surface conditions that negate extensive excavations. (This type of barricade was designed for the Navy.) Set in a foundation only ten to 18 inches deep, these shallow foundation barriers are able to survive and operate after a 1.2-million foot pound impact. With its shallow foundation and aesthetic design, they are major breakthrough in high-duty, anti-terrorist barricades.
  • Shallow foundation barriers eliminate concerns about interference with buried pipes, power lines and fiber optic communication lines while reducing installation complexity, time, materials and corresponding costs. These types of barriers are suitable for high water table locations and areas with corrosive soils.
  • Cable beam barricades are available in hydraulic and manually-operated models. All are crash rated, with one version enhanced for higher security applications. The clear openings range from 10.5 to 24 feet. One model is configured as a swing gate for use where vertical lift is impractical. All other models are raised to allow passage of authorized vehicles.

Bollards are Buff, and Beautiful

Bollard systems operate individually or in groups of up to ten, and are used for intermediate level security applications. Individual bollards are up to 12.75 inches in diameter, up to 35 inches high and are usually mounted on 3 to 5 foot centers. Hydraulic versions can be operated by a variety of control systems while manual versions are counter balanced and lock in the up or down position. All models are crash rated and lower to allow passage of authorized vehicles. They are also tested to stop and destroy an attacking vehicle weighing 10,000 pounds moving at 65 milesper- hour or a 20,000-pound vehicle moving at 46 miles-per-hour.

With bollards you can create the look you want. Ranging from faceted, fluted, tapered, rings and ripples, colors and pillars to shields, emblems and logos, bollards are aesthetically pleasing and versatile. Ornamental steel trim can be attached directly to the bollard, or select cast aluminum sleeves that slip right over the crash tube. If damaged, simply slip off the old and slip on the new. Bollards can also be galvanized for corrosion resistance, fitted with an internal warning light for increased visibility and engineered to suit high traffic volume.

Protecting perimeters of facilities is no small responsibility. Knowing you’ve got the right equipment in place to secure the facility and prevent human tragedy brings peace of mind that no amount of money can buy. Carefully researching available options and consulting with experts will ultimately lead to the right solution.

This article originally appeared in the August 2014 issue of Security Today.

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