The Four D's of Perimeter Security
by Robert Gruber, PSP
Master Halco Security Solutions Group

We’ve come a long way since the days of castles and moats with squawking geese for alarms and lifted drawbridges to delay access while pouring boiling oil and shooting arrows as a lethal response to invaders. However, the principles of perimeter security are much the same even though technology has certainly improved! Perimeter security still requires a total response that deters, detects, delays, and denies intruders access to vital holdings. Let’s briefly look at all four of these basic areas.

Deter
A few generations ago, perimeter security would have been concerned only with “deterrence.” Protecting the perimeter was somewhat of an afterthought. Once the main facility was built, access control and building security installed, the project team might say, “Oh, yeah, we better install a fence.” The fence, of course, is a great deterrent—I don’t have to convince any of you about that. It can be built as a strong decorative fence with heavy iron, or a chain link fence with barbed wire offsets and coiled razor wire. High-security fences are still designed with deterrence in mind and can be built to withstand a 15,000-pound vehicle traveling at 50 miles per hour, with a penetration of only 1 meter. This is the US State Department’s K-12 rating. You can also electrify a fence, bury the bottom of it, and put stacks of razor tape on top and along both sides. The professional intruder, however, will get to the other side. With the world’s situation becoming more and more dangerous in matters of terrorist activity, it has become very important to be able to detect, delay and respond at the perimeter in addition to deterring.

Detect
Detection is necessary because a person can climb over a fence. In a high security application, it is accepted that a trespasser will get through a fence within 4 to 40 seconds, so it becomes very important to convey information that someone has gotten over the fence, or is presently attempting to do so. This is where intrusion detection enters the picture.Fortunately, there is great technology available to handle detection. Remember the old Jimmy Cagney movies? Jimmy would break out of prison, with sirens blaring and searchlights illuminated to find him, but Jimmy always managed to duck under the light and get away. Well, now it would be somewhat more difficult. From fiber optics, to taut wire to electro-magnetic devices, intrusion detection has gone very high tech. There are even devices available that work like a meteorological system to constantly measure wind speed, temperature, humidity, etc., and compensate for normal changes in the environment, causing an alarm for only a rapid change. So, now we have “deter and detect.” The next step is to delay, and ideally we want the delay to equal at least the response time to deny a trespasser entry to critical infrastructure.

Delay / Respond
The response can be instant – turning on the lights, sounding a siren, or aiming a video camera along the perimeter at the point of intrusion. A longer response time is required if personnel must rush to the area. In that case, we may have to design layers of security using barbed wire offsets, bundles of coiled razor wire, and an inner fence to boot. Typically, a designer will aim for a 40 second delay at the perimeter by using a series of deterring devices.The best response systems also have the capacity to “talk” to each other via the use of TCP/IP, Telecommunications Protocol/Internet Protocol. All this capability can be integrated into one operating system. That system can perform all necessary security functions for the facility – functions such as creating badges, keeping employee files, saving monitoring logs of employees coming and going, viewing closed circuit TV, and of course, running the intrusion detection system. With this integrated capability, a fence breaching will instantly show up on a computer screen at the monitoring station or can be sent to someone’s PDA, and a response can immediately take place. The look and nature of our perimeter security is the deterrent. The technology we have in front of our perimeter and connected to the perimeter will handle the detection. Delaying an intruder easy access to the perimeter long enough to deny him access to critical infrastructure is the key.

Deny
So, why is the perimeter so important, anyway? You might think that if there’s good security at the door to the building, you’ll keep unwanted people or activity out. However, people with intention to harm only have to get next to the building to cause severe damage. Remember the Oklahoma City bombing. The perpetrator(s) never even had to leave the curb. Even if physical damage to a structure or facility is not an intruder’s intent, vital data must also be protected and trespassers denied access to critical information. When you add a total system solution of perimeter security to any building already set up with modern access controls, you create a modern “moat” that protects and secures the facility with as much lethal response as your customer requires.