Page 42 - Security Today, October 2019

Facility Security
Stop at the Point of Contact
MTaking sites less susceptible to vehicle attacks
he vast majority of discussions involving security and park- ing areas focus on protecting people and property from vandalism, theft or violent crimes. Thus, when planning security features for a new or existing parking lot or garage,
the first consideration must be the level of security required for that particular facility. A parking garage for a foreign embassy or federal courthouse will require far more serious security measures than a mall parking lot. Other primary considerations include the frequency of ve- hicles moving in and out and whether there will be vehicle inspections performed or a fully automated system at the entrance.
Reviewing Some Basic Physics Principles
When evaluating the security risk for a car bomber or crasher for a given facility, focus on the weights and velocities of vehicles that could be used to attempt penetration into sensitive areas. A vehicle moving towards 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 veloc- ity and its weight (mass). On impact, some energy is converted to heat, sound and permanent deformation of the vehicle. To stop the vehicle, the stopping point must absorb the remainder.
The remaining energy depends primarily on the velocity of the
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GOVERNMENT SECURITY OCTOBER 2019
By Greg Hamm
vehicle at the moment of impact. The amount of kinetic energy pos- sessed by a vehicle changes by the square of its velocity. A vehicle moving at 50 mph has 25 times as much kinetic energy as at 10 mph. An armored car weighing 30 times as much as a Toyota moving at 10 mph has less hitting power than the Toyota moving at 60 mph.
Because of the relationship of velocity to the total kinetic energy, the security engineer must make every effort to force a vehicle to slow down before it reaches the barricade.
Security Starts With an “S”
Straight lines make for faster and easier approaches for vehicles, so it’s best to create curves on access roads to your facility as a natural impediment to speeding cars or trucks.
The most frequently used technique is to require a sharp turn im- mediately in front of the entrance. When vehicle speed is reduced by 50 percent, “hitting power” is reduced four times. If the speed is reduced by two-thirds, the force of impact is reduced nine times. Fail- ing to understand this and not using the proper equipment to counter the threat leads to a false sense of security.
Upon designing a way to slow down vehicle approach, precau- tions should also be taken so that the attacking car cannot make a “corner cutting shot” at a barricade. Often, only a light post defines a