As a security manager, imagine a scenario where your first task every morning is to patrol the perimeter of your premises, scent-marking at strategic locations to protect your ‘territory’. Such an approach might work well for wolves and other such territorial animals, but it’s clearly impractical – not to mention ineffectual – for the human territorial animal. We mark out our territory with physical barriers and visible signs, leaving olfactory messages to our four-legged friends.
Don’t let this state of affairs fool you, though. The human animal is very resourceful and, for the criminal variety of the species, physical barriers are not always sufficient when it comes to deterring unwanted intrusions.
Fortunately, those who seek to keep criminals out share this resourcefulness. As such, physical barriers are very often supplemented with a whole host of other deterrents and detection devices. The end result? Integrated security systems that can be very effective indeed.
Perimeter protection, then, has ‘evolved’ into a sophisticated and sometimes complex area of operation. Indeed, the term ‘perimeter protection’ now covers a much broader range of security measures than in days of yore.
“To those of us greying at the temples, the original meaning of the term ‘perimeter detection’ may still be familiar,” suggests John Bowermann of GPS. “It described a system in which the external doors and windows were fitted with various types of magnetic or vibration detectors. There was no internal protection, though, such as the now seemingly omnipresent passive infrared detectors.”
“Theory had it that once the perimeter had been breached it was too late,” adds Bowermann. “Of course this did allow for free movement inside the perimeter while maintaining some form of protection. Over the last decade or so the term ‘perimeter protection device’ has been hijacked, and has generally come to mean any form of detection system that’s used outside. Whether it’s on the perimeter or otherwise.”
Marking out the boundaries
Where the security risk is relatively low, the fencing may do no more than mark out a site’s physical boundaries, but in most instances there also needs to be a ‘deterrent factor’ in the form of a barrier that’s difficult to get around.
As Mike Pollard of TWIL Fencing Division points out, however, fencing is often given scant regard in the original installation design, and can habitually suffer from a lack of imagination combined with a distinct unwillingness to spend any great amount of money on this part of the security equation.
“Architectural masterpieces blighted by such short-sighted frugality are not hard to find,” suggests Pollard. This is in spite of the fact that perimeter barriers are the first – and often the only – point of contiguity between people and the fenced structure itself.” This is a salient point that shouldn’t be lost. That part of a building which is visible to the public at large portrays the image of the organisation within.
How, then, can we provide a secure and at the same time aesthetically-pleasing exterior? Well, much will depend on the other types of perimeter protection slated for inclusion along with the fencing. For instance, if CCTV cameras are going to need a good view of both sides of the fence then it will have to be ‘transparent’. Welded mesh is often the fencing of choice.
As nature intended
From an aesthetics point of view, at least, there’s scope for using spiky plants such as bramble, pyracantha, hawthorns and blackthorn – preferably backed up with liberal helpings of stinging nettles for those trespassers who do managed to ‘scramble through the bramble’.
While such an idyllic scene would work well for many low risk premises, it’s clearly not enough for any organisation under a high risk of attack or threat. Let’s face it, you wouldn’t see security consultants specifying bramble and stinging nettles for the Credit Suisse First Boston building at Canary Wharf, would you? And, with more organisations buying into IT in a big way, corporate HQs and the like are attracting the attention of many a professional thief.
There’s nothing to say that nature can’t be emulated, of course, with the addition of broken bottles, barbed wire, razor wire and the like. And, if an array of spikes and other sharp surfaces isn’t appropriate, why not put a few volts through your intruder?
“If an intruder chooses to ignore the warning signs, and comes into contact with the protection system, a short, sharp, safe but nevertheless painful electric shock should be enough to repel them,” stresses Security Systems’ May George. While these measures may be considered an effective first line of defence against the enthusiastic amateur, when it comes to a determined professional, they will obviously need to be combined with a far more sophisticated approach.
CCTV back-up
At the heart of any truly effective perimeter security system is the CCTV set-up. “Perimeter protection and CCTV are inextricably linked,” states Bowermann. CCTV can form part of an overall perimeter system in several ways, the simplest being remote monitoring of perimeters. Although visible cameras can act as a deterrent to some, it’s not practical to expect guards to watch their screens day and night and remain 100% attentive.
A far more effective approach is to link the cameras to detectors which are only activated in response to a security breach, and can then hone in on that area. In this way, the screen will have the full attention of guards monitoring the system, and there will be more effective detection combined with verification of the alarm itself. This principle may be applied to external perimeters or the perimeter of the building (namely the doors).
At Welcome Break’s South Mimms motorway services, for example, electronic tagging of all goods on display in the shops is used in conjunction with detectors at the exits from the services. The next stage of system development will link the car park dome cameras to these alarms so that thieves can then be tracked back to their cars.
With the growing problems of light pollution from many exterior lighting design schemes, it will often make sense to link floodlights to the sensors as well – so that they are only switched on in the event of an alarm being raised.
Independent entities
Where CCTV and sensors are linked, it’s important not to make them dependent on one another. “We recommend that the two are linked but independent, so if visibility is poor for the cameras there are still sensors around for the security team to fall back on,” explains Bowermann. “Equally, if there is a problem with the sensors, the cameras remain operational.”
Verification is a big buzzword in the security industry at present. This applies just as much to perimeter protection as it does to intruder alarms. Early systems suffered from false alarm syndrome due to the weather, background noises or animals, and there have certainly been problems in getting fast police response. Equally as bad, guards would often complain about the alarms and fail to investigate (particularly during inclement weather).
With the development of cheaper, faster, more powerful electronics many of these problems are now being addressed. “The detectors themselves have remained pretty much the same for many years, but the ways in which signals are processed have become far more efficient,” notes Bowermann.
One of the key elements in the design of the system is to take account of the site specifics and adapt the security installation accordingly. This is just one of the reasons why systems can be relatively expensive. Skimping on cost, however, is only likely to lead to a set-up that does not work properly, and generates far more false alarms than ACPO – or anyone else – would like.
There is also talk of developing systems that can learn as they go along, and as the nature of the site changes. “Neural networks have the ability to learn sensor signal characteristics so that they can be trained to distinguish between nuisance alarms and attack,” explains Frank Boylan of Intelsec Systems. “With this ability they can also adapt to site-specific nuisances and changing environmental conditions, thus maintaining a high level of probability of detection with a low level of nuisance alarms.”
Perimeter protection systems have come a long way from the once-ubiquitous high fence and barbed wire systems. And it looks like they will continue to become ever-more sophisticated and reliable. Given the strange changes in weather patterns we are experiencing, perhaps they will also incorporate flood defences at some point in the future. An interesting concept…
