Your Crash Course on Creating a Vehicular Perimeter Security System

Here are seven factors to consider when deploying barriers, barricades and bollards for vehicle-based physical access control on your campus perimeter.
Published: March 27, 2011

1. Know the weights and speeds of vehicles. When evaluating the security risk for a given facility, particular attention must be focused on the weights and velocities of vehicles that would be used to attempt penetration into sensitive areas. A vehicle moving towards a barricade has a certain kinetic energy, which is the major measure of how much “hitting power” it possesses.  Mathematically, kinetic energy is derived from the vehicle velocity and its mass.  On impact, some of this energy is converted to heat, sound and permanent deformation of the vehicle. 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, but primarily the velocity of the vehicle at the moment of impact. The amount of kinetic energy posed by a vehicle changes by 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. 

2. Require vehicles to approach facility slowly. Because of the relationship of velocity to the total kinetic energy possessed by the vehicle, every effort must be made by the security engineer to force a vehicle to slow down before it reaches the barricade. Failing to understand this and not using the proper equipment to counter the threat may lead to a false sense of security.

The most frequently used technique is to require a sharp turn immediately in front of the barrier. When vehicle speed is reduced by 50 percent, the “hitting power” is reduced by four times. If the speed is reduced by two-thirds, the force of impact will be reduced by nine times.

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Upon designing a way to slow down vehicle approach, precautions should also be taken 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 and not even hesitate. Knolls and other impediments should be considered. 

Additionally, it’s best to create curves on the access roads to your facility as a natural impediment to speeding cars or trucks.

3. Deploy certified barriers. 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.

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.

4. Determine if active or passive barricades are appropriate. Normally, an active system keeps the barrier in the active or up position. It must be deactivated to permit access.  Active systems are preferable to ones that must be activated to prevent access because they are more secure. 

5. Mix aesthetics with functionality. With today’s smart designs, it’s no longer necessary to choose between form and function. You can have them both.  Designers are creating secure environments with more compatible and aesthetically pleasing architectural elements.

6. Determine if temporary barriers will work best. Quite often, vehicle access is required temporarily on campuses. Parking for a football game, a grand opening for the new wing, freshman matriculation day and open houses are temporary events needing only a temporary solution. Fortunately, such equipment now exists in the form of portable, towable barriers. These barriers can be deployed effectively in 15 minutes, even in places where it’s impossible to excavate for a permanent foundation.

These mobile crash barriers can be towed into position by a medium-sized pick-up truck or equivalent. They operate locally or remotely for guard protection.

Deployment, retrieval and operation are all hydraulic. The barriers stop and disable a 15,000-pound vehicle moving at 30 mph. Once positioned, the mobile barricade is separated from its transporter and lowered into place by means of a battery-operated hydraulic power system, which is then used to raise or lower the barrier for normal or emergency tasks.

7. Consider permanent barriers, barricades and bollards. Solutions include beam barricades and high security shallow foundation barriers. Manual beam barricades look like the classic bar that comes down but will stop a 15,000 pound vehicle traveling 50 mph dead in its tracks. It takes only one person to operate them.

High speed, high security, very shallow foundation barricades can control vehicles going in and out of a facility. These barricades were created for high speed actuation and quick installation. With their extremely shallow foundation, they reduce the concerns of interference with buried pipes, power lines and fiber optic communication lines. The shallow foundation also reduces installation complexity, time, materials and corresponding costs. They will stop a 15,000 pound vehicle traveling 50 mph.

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Strategy & Planning Series
Strategy & Planning Series
Strategy & Planning Series
Strategy & Planning Series
Strategy & Planning Series