Barriers revisited—new possibilities with an old capability - highway engineering

Military Police, March, 2002 by Robert Reaves

Barriers are as old as civilization. From farmers stacking stones to protect a property line to engineering marvels like the Great Wall of China built to protect a civilization, barriers have marked where people were allowed to go. Ditches, berms, moats, hedgerows, and tree lines have long been used to delineate boundaries. A willing populace has generally acknowledged and respected these lines; however, those less compliant required stricter enforcement methods. As a result of this requirement, a sector within the physical security profession has responded to the challenge and met the need.

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For years, the security barrier has been seen as inconvenient, unsightly, and bothersome and, in its crude form, it still is. As a result, its use has often been limited due to aesthetics. Now, the lowly barrier has been rediscovered as the primary multipurpose tool in our security and force protection toolbox. It is now being used for a variety of purposes, most notably for--

* Access control.

* Traffic management.

* Blast mitigation.

* Ballistic protection.

When we speak of barriers, most people think of the concrete jersey barrier--those ugly, gray things that line our highway construction sites. Though it is the most visible and often used, it is only one member of the barrier family. These barriers were designed to channel vehicular traffic. When installed parallel with the flow of traffic, vehicles cannot leave their respective lanes and, if they strike the barrier, severe damage or injury to occupants is unlikely. However, striking these barriers head-on, at right angles, will cause severe destruction, possible catastrophic injuries, and significant property damage.

Military installations use concrete barriers primarily to prevent vehicles from approaching or parking too close to buildings or other vulnerable areas. As a result, their role has received increased scrutiny. Recent barrier evaluations and blast tests have identified the most and least effective means of employing barriers for this purpose. Ineffectively employed barriers are no more than wasted efforts--symbolically false and unproductive hindrances, impeding sanctioned movement and creating a false sense of security. And in the worst-case scenario, improperly employed barriers can become added deadly shrapnel at the leading edge of the destructive effects of an explosive device. The bottom line here is that the proper mission analysis, selection, installation, and employment of any barrier style are critical to its success.

For years, the private sector has used many different sizes, shapes, colors, and styles of barriers designed to do different missions. Due to the importance of image, it demanded improvements and the security designers and manufacturers responded. They took a page out of the military's physical security lesson plans and incorporated the principle of "security through environmental design."

Today, corporations and engineers often factor security into the construction and landscaping of their offices and manufacturing facilities. Most parking areas are now set away from buildings, and landscaping channels foot traffic to designated avenues of approach. Earth berms and shrubbery are now positioned to absorb or mitigate blast overpressure and shrapnel. These initiatives prove that barriers can be engineered to be both effective and aesthetically pleasing.

However, once a building has been constructed without considering security as one of the primary factors, the portable/ temporary barrier becomes a vital part of the facility's security posture until retrofits can be made. The Department of Transportation (DOT), Department of State (DOS), and Department of Defense (DOD) have developed and adopted standards for barriers and their customary use in these cases.

The Maneuver Support Center's (MANSCEN's) Directorate of Combat Developments (DCD), the Program Manager-Physical Security Equipment, Department of the Army, and the Department of the Air Force have tested different types of barriers to meet these needs. They have conducted crash, ballistic, and explosive tests to ensure that vendor's claims met the services' requirements. Before acquiring any barrier, it is essential, and highly recommended, that the buyer takes the time to review the test and evaluation results.

The MP, the physical security proponent, are very involved with the test and evaluation of these products or systems. The development of new materials and technologies has given rise to modernized designs and improved capabilities. The following is a compilation of barrier initiatives currently available, or under consideration, for use by the DOD and other government agencies:

* The portable vehicle-arresting barrier (PVAB). This system was designed to capture light-wheeled vehicles attempting to forcibly gain entry to limited-access areas. This system is easily emplaced, and its nonlethal net barrier can be deployed remotely in less than two seconds and catch a 7,500-pound vehicle traveling at speeds up to 45 miles per hour. Capabilities and requirements associated with this barrier include-