Electrified security fence systems are becoming mainstream as they are proving highly effective at preventing intrusion and theft. Graham Harper of Harper Chalice Group describes the essentials for using them.
The use of electrified perimeter fencing is becoming much more widespread and is no longer the preserve of high security government facilities or major utilities. The spread of this versatile and effective security tool to commercial properties is being driven by a perceived rise in the risk of major thefts. As fuel and commodities become more expensive, and economic hardship continues to bite, locations such as storage yards, depots and commercial premises present an attractive target to thieves.
There is no question that electrified security fences deliver real protection. They are proving to be one of the most effective security tools for any risk manager struggling to protect a crime-prone site. What is particularly impressive about these systems is the way they stop criminals in their tracks, in a way that ‘soft’ electronic security technologies such as alarms and CCTV on their own, can’t. Electrified security fencing delivers a short, sharp, painful but regulated safe electric shock to anyone attempting to climb or tamper with the fence. It not only repels the would-be intruder but acts as a powerful psychological barrier to anyone even thinking about breaking in.
Where
In many cases systems are installed as a preventative measure, for example at economic key points which are required by the government to be protected using approved security measures (utilities, transport hubs, power stations etc). But looking to the wider market, to small and medium companies, electrified perimeter fencing is now being used to stamp out recurrent theft problems. There are many examples in which systems have been installed in crime-prone areas, where the user has suffered a history of repeated attacks and where, sometimes as a last resort, police or insurers have recommended that electrified fencing is deployed. In all these cases, without exception, the attacks and losses have stopped overnight.
In our experience, often such users are surprised that nobody has previously suggested to them that they use electrified fencing. In some quarters there are still misconceptions about this technology which is why the three points we continually stress are: 1) they are safe, 2) they are legal and 3) yes, they really do work. Systems are available which are approved under the Secured by Design (Police Preferred Specification) scheme and so long as they are installed in accordance with BS1722 Part 17, and BS EN 60335-2- 76:1999 they can be used anywhere, even in busy city centres. One of our recent major installations is at a high profile sporting venue – at the other end of the spectrum, a system has just gone in to protect a caravan park in Wales.
Safety and standards
On safety there are various considerations. First, the maximum energy that can be produced is limited to five joules into a load of 500ohms (the typical resistance of the human body); secondly the systems must be installed in such a way that people cannot accidentally touch them; there must be adequate warning signs; and there must be no danger of people becoming trapped in contact with the electrified wires. There are various other considerations which properly trained and accredited installers will be conversant with – more detail is included on our website – and all systems should be signed-off and certificated as compliant by the manufacturer.
Here it’s worth adding that electrified fencing systems are not expensive compared with other electronic security measures – a typical system requires less than 5 Watts of energy per 100 metre zone – and they are much less visually intrusive than ‘high security’ perimeter barriers such as razor wire or elaborate rotating topping systems.
System essentials
Electrified systems can be used in a number of ways. For example as fence toppings, as a full-height secondary fence line, or mounted onto building structures such as walls or roofs. The best systems can be fully integrated with CCTV, alarms, lighting and other security technologies. The latest generation technology can also be configured to operate in variety of modes – for example in detection-only, in active pulse-on mode, or a combination of the two. But to achieve the optimum level of protection with electrified fencing, there are important considerations when choosing which system to specify.
Make sure the technology you pick is up to the job. A lot of electric fence ‘security’ systems are not that secure – they are simply developments of agricultural fencing that may not be installed to the correct standard and as a result are easily overcome by intruders with little knowledge of how the systems work.
Key points to check on any systems are: how wide is the spacing between wires (for maximum security, 50mm spacing is recommended; for general applications 100mm is used), how robust and fit for purpose components are and how resistant the overall design is to all weather conditions. On the latter question it’s worth asking if the product is approved by the Home Office and Secured By Design, Police Preferred Specification as evidence of the systems’ proven performance. Choose a system that meets the security requirements and is easy to maintain. Another advantage of electrified systems is they are far less visually obtrusive and far more effective than other topping’ products like heavy rotating or dense razor wire coils. Choose a system with tensioning springs on each wire to maintain the wire tension during all temperatures. Some system do not have this feature resulting in the wires under high tension placing a huge amount of strain on the fence posts or mounting structures. This tensioning can cause real problems – with posts being pulled out of line, or failing altogether. For this reason we use lighter grade wires which can be installed more quickly and in many more locations (for example, reinforcing existing fences). Experience has shown that there is no security advantage to using thicker wires – a point borne out by attack trials time and again.
Avoid systems which require a lot of maintenance – we recommend two routine maintenance checks each year in addition to routine perimeter house-keeping, such as controlling undergrowth. Some designs are prone to false alarms, for example if air-borne contaminants build-up on their insulators they require hosing down regularly – especially in coastal locations. On extensive boundaries frequent maintenance is obviously expensive and should be avoided.
About the author
Graham Harper is managing director of Harper Chalice Group Ltd, the manufacturer and supplier of electrified perimeter security systems and perimeter intrusion detection systems (PIDS). It makes the PulseSecure PROTECTOR Enhanced electrified perimeter system, and FenceSecure, for high risk/security sites, data centres, prisons and high profile sporting events. Visit –
