Fog on the crime

Believe it or not, the use of smoke as a form of defence is not a new idea. In truth, the ancient Chinese were the first pioneers. In the modern era, artificial smoke generators - developed in the early 1970s by a number of manufacturers for the fire training and entertainment industries - were adapted for use in secure storage facilities, and even on vehicles operated by Johnson Matthey.

Inaugural ‘commercial' security systems appeared in 1993, with the original Smokecloak product winning the innovation award at CMP Information's IFSEC Exhibition.

Since then, the popularity of smoke systems has grown, but - somewhat surprisingly - not all end users have bought into the idea. So why the reluctance?

In the early 1990s, cynics within the security arena described security smoke systems as a flash-in-the-pan. Then, as now, there was an inherent reluctance to try anything new. One suspects that many Boards of Directors also railed at the suggestion of smoke - with all its connotations of toxicity and fire - being used to fill their premises in the event of any attempted (and most certainly unwanted) burglary.

Consequently, the majority of end users have specified CCTV in the belief that it will prevent acts of criminality. Sometimes cameras will deter villains by presence alone, but on other occasions they will not. By and large, CCTV is used for detecting crime. First and foremost, it is not a crime prevention tool.

Traditional security philosophies have always relied on the deterrent effect and, one supposes, the timely arrival of the police. That said, today's thief is only too aware of UK crime statistics. A good police response is seldom less than ten minutes away, but most burglaries are done and dusted in five.

Prevention rather than cure

Not only do smoke generation systems prevent crime, the concept behind them is simplicity itself. A smoke generator is connected to a conventional intruder alarm. When triggered, the system produces vast quantities of dense, white smoke that's sufficient to reduce visibility to the point where you cannot see the hand in front of your face.

That smoke is harmless, by the way. It's produced by passing a chemical stimulant - usually a food grade glycol/pharmaceuticals-based concoction, or a glycerine mixed with purified water - through a heat exchanger. This vaporises the chemical, which then condenses as it leaves the machine by way of a special nozzle. The end result is a dense fog formed by billions of microscopic particles. It's tasteless, odourless and harmless - but hugely effective.

If the smoke is produced properly it will not leave any form of contaminating residue. The supposition that this isn't the case could be one of the reasons why end users in office environments, for example, have baulked at the idea. After all, if your workspace is filled with computers, fax machines, photocopiers, printers and other expensive forms of IT hardware you could do without it being damaged. In truth, the vapour from security smoke generation systems eventually disperses, leaving no residue at all.

The rate of smoke dispersal is an important factor. If it were to recede too quickly, the criminals on your premises could continue to steal and/or do damage. If the internal environment is stable, the smoke should start to clear after half an hour or so. Discerning security professionals will posit a ‘What if?' question at this point. As in: "What if the thieves can locate a door or a window and open it to let the smoke disperse?" Fair point, but the sophisticated solutions now available from companies like Martin Security Smoke allow smoke intensity to be monitored and densities automatically boosted if levels are low.

Smoke systems must be installed with great care, and located in an appropriate place. Preferably, this will be high up within the space (up to heights of eight metres in warehouses, in fact) with the smoke nozzle itself pointing either straight down or at an angle such that the fog may be released at a quicker rate. Also, if the intruder cannot access the system they cannot attempt to block the nozzle.

To billow into a cloud, the vapour from the smoke system must hit a solid surface, such as a larger table or maybe the floor. That being the case, make sure your installer positions the nozzle correctly. This is most important in retail spaces, where zonal smoke protection is initially introduced (ie the smoke is directed to fill certain areas where there are expensive electrical goods, for example, and/or to cover the entrance zone) before the entire space is shrouded in dense smoke.

Remember that you could look towards a two-stage activation process. When the intruder alarm is activated, the smoke generation system is armed, but will only emit its vapour if and when a second dedicated confirmation sensor is activated by some secondary motion in the area being protected. In other words, an alarm activation would not generate smoke production unless human activity is detected in the space.

If you want to go a stage further in protecting your company's buildings and the property within, it's possible to add both sound and lighting barriers that will disorientate criminals still further. 3000 W long-life Xenon strobe lamps are now available, offering unparalleled intensity in terms of the ‘blinding' effects they produce. They are not ‘toys' with an interesting flash effect as would be produced in a night club, but a brutally efficient deterrent. You have to experience this effect to appreciate it. It really is most disturbing!

The better strobe systems are sabotage-proof, such that they may be located in public areas or concealed in roof spaces if that's your preferred option. Customised mounting assemblies will allow you to mount the units on office walls, in corners, on the ceiling or around the edges of buildings.

Instant sound protection may also be specified. Systems capable of emitting 125 dB of intolerable sound at a range of just one metre are now available for specification. The effect on their ‘victims' is very unpleasant.

Key points for specification

What, then, should end users be looking for when specifying a protective smoke generation system? First of all, check that your chosen system is manufactured and supplied by a reputable company. Typically, the manufacturer will have quality assurance accreditation (to IS0 9001:2000) and adequate product liability insurance.

The system must be manufactured to BS 7939 - the British Standard for such systems - and, in an ideal world, be listed on the Secured by Design police preferred specification schedule of ratified products.

Has the model you are looking at been independently tested to show accreditation? Is the smoke generator truly designed for the rigours of security work?

Finally, what follow-on support is being offered? You should be expecting nothing less than a robust public and product liability cover, in addition to adequate after-sales service (mainly on the technical side of the equation).

When first introduced, security smoke systems were derided as a gimmick. However, 13 years later no-one is laughing. Certainly not the thieves who are 'blinded' and totally inhibited by these systems.

Generally speaking, smoke-based security systems are less obtrusive than conventional security measures (including bars, shutters and grilles), less expensive than conventional physical security and CCTV, are more effective at physically stopping losses than an intruder alarm system and often capable of preventing loss where all other conventional security methods have failed.

Several well-known High Street names - including The Carphone Warehouse, Barclays Bank, The Dixons Stores Group (encompassing The Link and PC World) and Blockbuster Video, companies that simply cannot afford any damage to their reputation - are deploying them as their primary defence mechanism to fend off smash-and-grab intruders. And why not, indeed? After all, thieves cannot steal what they cannot see.

Barclays has benefited enormously from using smoke generation systems. The company was having major problems with branch thefts in the North West region. Assailants were brandishing guns and knives. In recent years, sliding screens activated by bank tellers to combat such attacks have fallen out of favour due to the liability issues involved with injuries. Having convinced the Board to trial a smoke system, within eight weeks Tony Bayliss - head of crime and intelligence management for UK banking at the Barclays Group - ensured that no less than 11 sites were duly kitted-out.

The outcome? Since then, there have been only four attacks on Barclays' premises in the region, all of them successfully thwarted.

Bayliss' colleagues in the industry who prefer to remain conservative at specification time would do well to open their eyes to such technology. Seeing - or, in this case, not seeing - really is believing.