Electrical Security Fencing - What You Need to Know

Electric fencing has been used for agricultural purposes for many decades and electrical security fencing is now being used around a variety of commercial and secure premises. In our latest blog we look at this form of highly effective perimeter security.

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History of Electric Fencing in the UK

The use of electric fencing in the UK has evolved from relatively simply agricultural applications to the sophisticated property security systems used today.

Electric fencing was initially used in farming to keep livestock contained. The popularity of electric fencing for agricultural applications developed significantly after World War II when farmers needed a low cost solution to keep animals in a specific area, or prevent them from entering.

The electric fencing systems used by farmers at that time, as a replacement for more expensive wooden fencing, were very basic. They consisted of three primary components, the energizer, the fence wire and the earth or grounding system. Basic energizers were battery powered, often using a car or tractor battery. Later designs could use mains power but the remote location requirements for agricultural electric fences often meant that battery power was the most practical option. Early agricultural electric fencing energisers produced short, intermittent electrical pulses around every 1 to 2 seconds and didn’t deliver a continuous current. The electric fencing wire was generally plain steel or galvanized and the earth or grounding system consisted of a metal spike pushed into the ground.

Early systems were low voltage, high impedance circuits running at around 2,000 to 5,000 volts with a very low current delivering capability that wasn’t high enough to cause injury. When an animal came into contact with the electrified fencing wire a pulse of electrical energy passed through the animal to earth, startling the creature but not causing any harm.

If the ground was dry then the shock delivered to the animal was weakened. And if the fence wire came into contact with weeds or other vegetation this would potentially cause a short circuit, draining the battery power. Early battery powered agricultural electric fencing was notoriously inefficient and some systems could deliver unpredictable electric shocks leading many farmers to avoid using them.

The agricultural electric stock fencing systems underwent significant improvements including the introduction of insulated fencing wire, higher reliability energizers and some solar powered systems.

The Agricultural (Safety, Health and Welfare Provisions) Act 1956 addressed risks from farm equipment, including electric fencing. These regulations made proper insulation mandatory along with appropriate warning signage. The Health and Safety at Work Act 1974 introduced general safety duties, affecting electric fence installation and maintenance. And the Electricity at Work Regulations 1989 required that electric fencing must be properly insulated, not pose any risk of electrocution to humans or animals and must comply with voltage level restrictions (typically under 10,000 V for agricultural fencing).

Electrical Security Fencing

Early installations of electrical security fencing were implemented in the 1980s and 1990s around prisons, military sites and some high value, commercial properties. The HSA states that the first system installed to deter unauthorised persons from entering a property was carried out in 1992.

These electrical security fencing systems differ from the basic systems used for stock control in agricultural applications. They use higher voltages but must still comply with strict regulations to prevent potentially lethal shocks. The Anti-social Behaviour Act 2003 (Section 31) made it illegal to install electric security fencing that could endanger the public and made it mandatory to clearly display electric fencing warning signs.

How Does Electrical Security Fencing Work?

Unlike agricultural electric fencing, electrical security fencing systems use higher voltages and are often integrated with alarm and monitoring systems. The primary components of these systems are basically the same as the agricultural systems (energizers, fencing wire and grounding system) with the addition of monitoring and alarm integration.

The regulations that apply to using electrical security fencing are notably more strict than those that apply to agricultural electric fencing. Systems used around prisons, for example, must comply with BS EN 60335-2-76 along with Prison Service Guidelines.

The system energiser converts either mains or battery power into high voltages, typically in the range of 5,000 to 10,000V, significantly higher than the levels commonly used in agricultural systems. The energizer deliver pulses of electrical current to the fencing which is often stainless steel or aluminium wire, mounted on robust, rigid frames. The pulse frequency used in security fencing tends to higher than the frequency used for agricultural systems. In prison applications the fencing consists of multiple layers with the electrified wires sandwiched between anti climb mesh fencing on the inside and possibly razor wire, or another form of anti climb fencing, on the outside.

Prison systems are primarily intended to keep the inmates inside while electrical security fencing around commercial properties is intended to keep intruders outside. When someone comes into contact with the electrified fencing they complete a circuit to ground and they experience a very unpleasant electric shock, lasting just a few milliseconds. This causes involuntary, painful muscle contractions that are non-fatal. The pulsed delivery of energy to the fencing enables anyone who comes into contact with the circuit to quickly recover but deters any further attempts to overcome the barrier.

Wherever electrical security fencing is used it is mandatory to clearly display appropriate warning signs saying something like: “DANGER - ELECTRIC FENCE”.

Electrical security fencing around prisons is typically used in conjunction with microwave motion detection and CCTV security cameras. Establishments using this form of perimeter security have never experienced any successful escapes.

Dangers of Electrical Security Fencing

Compliance with strict UK safety standards means that electrical security fencing is a very effective deterrent and not a deadly hazard. But unfortunately there have been some incidents in which people have been injured, generally as a result of misuse, faulty installations or due to bypassing safety features.

In 2016, an inmate from HMP Lindholme suffered significant burns and muscle spasms after being incapacitated by an electrified perimeter security fence. And another inmate, from HMP Preston, suffered severe burns after throwing a wet blanket over and electrified security fence in an attempt to short circuit the system.

In 2008 a child was burned after climbing onto an electrified fence surrounding a high value property. The court determined that warning signage was inadequate. And in 1999 a farmworker died after touching a poorly maintained agricultural electric fence that had faulty wiring. The system faults caused a continuous current flow, preventing the worker from releasing themselves from the fence.

While the risks of someone being killed by an electric fence are very low, due to low current and short pulse duration, system faults can prove to be fatal. And if a person coming into contact with an electric fence has a pre-existing heart condition they are at higher risk.

Illegal Electric Fencing

Both agricultural electric fences and electrical security fencing, that are fully compliant with strict UK regulations, don’t present any significant risk of causing injury. But there have been cases in which people have contrived their own, home-made illegal systems, often using mains electricity at 230V AC.

In 2018 a Derbyshire farmer configured his own mains powered electric fence to deter thieves from his property. When a trespasser received a severe electric shock the incident was reported to the authorities. The HSE investigation revealed that the system did not use a compliant energiser and wasn’t delivering pulses of compliant electrical energy to the fencing. Instead, the fencing exposed a highly dangerous, potentially fatal 230V mains connection with no warning signs. The farmer responsible was fined £5000 under the Health and Safety at Work Act.

In Lancashire, a man troubled by repeated burglaries, connected his fence to the mains in 2011. This resulted in a burglar being hospitalised after suffering a severe electric shock.. The homeowner was arrested but avoided being charged after arguing his actions were ‘self defence’.

And in Scotland, a landowner connected a metal gate to the mains power supply in 2009, to deter trespassers. A local postman suffered a severe electric shock when he attempted to open the gate. The property owner was prosecuted under the Electricity as Work Regulations 1989 and fined £3,200.

Installing Legal Electrical Security Fencing

People often want to know if they can install their own electrical security fencing. While it is entirely possible and legal to install these systems there are strict legal and safety requirements that generally make it more sensible to employ the services of a professional electrical security fencing installer. Penalties for illegal installations can include fines up to £20,000, criminal charges and forced removal of the system.

Professional installation services are always required for high security sites, such as prisons and military establishments. Commercial properties must comply with strict HSE regulations making it prudent to use the services of professionals who are specialised in these installations. And integrating electrical security fencing systems with CCTV, monitoring and alarm systems is generally best achieved by experienced professionals.

Non-Aggressive Perimeter Security with Roller Barrier

While it is clear that aggressive electrical security fencing has a valuable role to play in ensuring security around prisons, MOD properties and some commercial sites, there are many circumstances in which aggressive perimeter security systems are entirely inappropriate and unneeded. If an entrance gateway, perimeter wall or fence needs to be protected against unwanted trespassers or climbers an effective, non-aggressive solution is Roller Barrier.

Roller Barrier is now widely deployed on a wide variety of sites all around the world. These include schools, psychiatric hospitals, commercial goods yards, public buildings and private, domestic homes. In any situation where there is a need for protection against intruders or simply climbers, Roller Barrier is providing the required security, without introducing any additional risk of causing injury.

Roller Barrier works by presenting an unstable, rotating barrier that simply can’t be gripped or climbed over. And if someone attempts to breach the hurdle there is no chance they will be electrocuted or impaled on nasty spikes. This key non-aggressive attribute of the Roller Barrier system is why it has become the preferred anti climb solution for any establishment or property where children or vulnerable people are involved. Youngsters love to climb and show off so rooftops, walls and fences can often be irresistible to them. But when they climb onto flat rooftops or scale fences they can sometimes cause expensive damage while putting themselves at serious risk. Aggressive anti climb solutions are totally inappropriate for these situations which is why Roller Barrier is now widely installed in and around many schools, youth centres and other establishments. And many home owners with children are now using Roller Barrier to prevent their own children, along with their friends, from clambering all over their properties.

For more information on Electrical Security Fencing - What You Need to Know talk to Insight Security