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The big deal with barriers.

WHY WOULD ANYONE NEED A security barrier when a good alarm system will solve most security problems? Because barrier systems represent a critical link in the overall security system. They make it difficult to enter a facility or to gain access to assets. The function and design of barrier systems, where they fit in an integrated security design, and how vulnerabilities and perceptions about barrier systems can affect overall security performance are all essential considerations.

A barrier is, of course, an object or structure intended to prevent passage. A barrier system, therefore, is a set of components that make up the barrier unit. A fence is a barrier because it is a structure intended to prevent passage. However, a basic fence is composed of fabric, posts, wires to fasten the fabric to the posts, concrete foundations to keep the posts in place, gates with hinges, and locking devices. These individual components make up the complete barrier system known simply as a fence.

Now take a closer look at the simple fence. The fence is installed as a barrier system to deter some level of threat. It needs to have certain characteristics that meet the user's requirements. If the threat is low, like someone simply walking on the property, a 4-foot-high picket fence may be adequate. However, if the threat is vandalism or theft, a 7-foot-high wall with barbed wire and razor tape on top may not be enough.

Barrier systems come in a combination of sizes, shapes, materials, and components. Each system is intended to provide some level of protection against a specific threat. But each barrier system, whether it is a door, window, wall, fence, vault, or security container, must be thoroughly analyzed. The system should be tested to ensure that it provides the intended level of security.

Where does a barrier system fit into an integrated security system? Solutions to the problem of lost assets have been to increase the size of the police or private security forces, install better locks or intrusion detection systems, or accept the loss as a cost of doing business.

Police and security officers have some deterrent value, however, their fight against criminal activity is primarily reactive rather than preventive. The exception is when the criminal is actually caught in the act or in situations where an on-site officer protects the asset, which is an expensive security alternative.

Most criminal activity involves low-level crimes of opportunity. The criminal is ensured easy access and egress, without the threat of being captured or identified. By the time police or security officers respond to an incident, the thief is usually gone, often along with the assets.

An increase in police or security officer forces typically does not result in a cost-effective reduction in the loss of assets, primarily because these forces cannot do the job alone. Police and security officers, locks, barriers, and intrusion detection systems all play important roles in defeating threats. None of them is a stand-alone solution.

A recent example of this unfolded during the Los Angeles riots in April 1992. The police were so spread out that they could not respond to many of the crime incidents. Thus, the response component of the security equation was eliminated.

In many cases, buildings were equipped with sophisticated alarm systems, but the systems made little difference to those who broke windows and grabbed items that were not nailed down. Would anything have prevented the vandalism and looting in Los Angeles? The answer comes in analyzing the threat and developing a system to deter or delay the threat until the police can respond to the alarm.

During a major riot situation, such as in Los Angeles, it would have been necessary to delay intruders for hours instead of minutes. But barrier systems are available that would have prevented much of the criminal activity that occurred. For example, many storefronts in the riot area were equipped with expanding steel barriers. However, the barriers were not well attached at the top or bottom and were secured at the leading edge with only a small padlock. These weak barrier systems offered no deterrence and were quickly defeated by the rioters.

Substantial evidence from the Los Angeles riots indicates that some barriers did deter the rioters. For instance, roll-down doors or barriers protected some businesses from attack. It is not clear if the deterrence can be completely attributed to the barrier system itself. Assets simply may not have been worth enough to warrant the effort or perhaps there were easier targets next door or down the street. Many of these reasons, however, demonstrate the value of barrier systems.

BARRIER SYSTEMS PROTECT AGAINST different levels of threat and their component vulnerabilities can affect overall security protection. To illustrate, go back to the common fence. If the goal is to prevent or deter people from climbing over the fence, look at its materials and attachment mechanisms that will prevent these attempts.

Select materials that do not have handholds or footholds. Ensure that the barrier cannot be easily toppled, dismantled, or bypassed from the outside.

Look carefully at the gate system to ensure that vulnerabilities are not inadvertently created. These vulnerabilities may take the form of hinges, locks that can easily be removed, or footholds that allow easy scaling of the gate. The gate system must provide the same level of protection as the rest of the fence or the company is wasting money.

This philosophy holds true when designing any other barrier system whether it is a door, window, or wall. Attention to security design details will ensure a cost-effective design that addresses the identified threat. Selecting a door panel that is weaker than the wall, installing hinges that can be removed easily or attacked from the outside, or using a locking system that can be stripped off in seconds negates the usefulness of the barrier system as a deterrent, delay, or denial system.

The key to designing a barrier system is to characterize the threat to the asset. Consider the value of the asset, its usefulness to the potential intruder, and the skill the adversary must possess to overcome the barrier design. By studying events such as burglaries and riots, enough information can be collected to make barrier selection and design easier.

Starting at the lowest level, structures such as bakeries and barber shops that contain assets of nominal value to would-be thieves would represent the lowest priority on a target list. Therefore, only nominal security protection would be warranted, such as standard glass windows, standard doors, and dead-bolt locks.

For structures with medium-level assets, such as clothing, electronics, and furniture, alarm systems and barrier systems may be necessary. These would provide protection against an unsophisticated attack with common hand tools, such as pry bars and bolt cutters.

For high-value assets in businesses, such as gun shops, jewelry stores, and banks, the necessary level of protection rises. Sophisticated alarm systems and barriers may be required to provide substantial protection against a criminal with an arsenal of tools and techniques.

Barrier system protection in this case can include polycarbonate glazing for glass, industrial door systems with interlocking dead-bolt locks, and hinge-side protection. The introduction of auxiliary security equipment such as vaults and security containers may provide additional delay or deterrence against an intruder.

THE DELAY TIME CREATED BY BARRIER systems is an important factor in providing asset security. Delay time is the time it takes to make an opening in a barrier large enough for a person to pass through. In addition, it refers to the time it takes for the closure system, such as a door or window, to be defeated.

Delay time can also be defined as the time necessary to achieve a specific level of protection. As an example, the delay time can be tied into the response time for the police or security officer forces, or it can simply relate to the delay time provided by the security components of the structure.

Considerable confusion exists about the delay capabilities of security hardware. Exhibit 1 provides a way to categorize threats, lists the characteristics that apply to each threat level, and includes the tools used in each type of attack. This information can be used to establish a basis for delay times and in turn to apply protective systems to a facility's design.

Common criminal threats can be translated into meaningful data. In Exhibit 2, threat and security levels are related to delay times of security components and the basic construction of the facility.

Delay time for security barriers and components is based on forced-entry testing of the selected item using specific tools. The size of the opening is normally 96 square inches, so penetration data can be easily compared. The delay time represents actual working time with no penalties for mechanical failure or rest periods. This process provides a conservative delay time value that can be used reliably in the design process.

Once the threat and delay time for a specific facility have been established, security components that provide similar levels of protection must be selected. Currently, the only way to measure how a security component will perform under a given set of circumstances is to test the product.

Delay systems can be segregated into three general categories, which are often referred to as layers: perimeter protection systems, facility protection systems, and interior protection systems. Barrier systems fit into all of these categories.

Barriers are critical components of any well-designed security system. They provide initial deterrence to a variety of threats and represent a quantifiable delay time. Alarm systems cannot delay an intruder and usually provide notification only after the intrusion occurs. Therefore, delay, detection, and response components must be engineered and integrated to form a cost-effective security system configuration.

Gary R. Cook is director of the Security Engineering Division, Naval Civil Engineering Laboratory, in Port Hueneme, CA. He is a member of the ASIS Standing Committee on Security Architecture and Engineering.
COPYRIGHT 1992 American Society for Industrial Security
No portion of this article can be reproduced without the express written permission from the copyright holder.
Copyright 1992 Gale, Cengage Learning. All rights reserved.

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Title Annotation:importance of barriers in overall security system
Author:Cook, Gary R.
Publication:Security Management
Date:Nov 1, 1992
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