Protecting the vulnerable – in defence of sprinklers

I REFER to the letter from Dr Bob Docherty (Fire Risk Management, March 2009, p.6), which essentially challenges what we believe is a most constructive and helpful article in the National Fire Sprinkler Network (NFSN) supplement produced in November 2008. The article in question was written by Steve Beckley, who is CFOA’s national lead officer for fire safety – technical standards, and currently deputy chief of West Yorkshire Fire and Rescue Service.

To put this in some sort of perspective, the NFSN, as part of its tenth anniversary, produced the supplement to celebrate 10 years of sprinkler success through working together. Mr Beckley’s article, ‘Protecting the vulnerable – the case for sprinklers’, outlined the changing care needs with an ageing population, the legal position, the business case, and the benefits of sprinklers, indicating how these systems can help managers in the residential care sector to justify staffing levels and evacuation procedures.

Firstly, in relation to Dr Docherty’s comments, the article did not attempt to claim that sprinklers were the panacea for all things fire safety, simply that, in certain circumstances, they can make the fire risk assessment so much simpler (control the fire size, and everything is much more straightforward – a basic principle applied by fire engineers throughout the world).

The second point to be made is extremely important – we know from our experiences that, while Approved Document B to the Building Regulations in England and Wales may ‘quite plainly and simply’ differentiate between residential care and sheltered housing, assessing the needs and risks of the occupants of both can be a lot more complicated. The article was attempting to underline the fact that, in practice, there is significant crossover in terms of the actual residents. In some cases, the occupants of sheltered housing may be at greater risk than those in residential care. Dr Docherty underlines our concern that some people do not understand that the risk assessment must, first and foremost, take account of the risk of those present, should a fire occur.

We totally agree with Dr Docherty that the 2.5 minute evacuation time is unrealistic. But, if a fire risk assessor works out the likely fire growth and smoke movement in a building, the likely response of residents and, where necessary, the likely time it would take for staff to assist in evacuating those at risk to a place of relative safety, they could reach some sound conclusions. If the estimated evacuation time is greater than the predicted fire/smoke spread, then clearly the fire precautions are inadequate. The fitting of sprinklers makes this calculation far simpler and more predictable.

We would prefer not to get into the legal arguments (although raised in Mr Beckley’s article) because, again to reinforce the whole point of the article, the fundamental issue is that those most at risk deserve the best possible protection. Whether the Fire Safety Order applies or not is avoiding the issue completely, and to try and argue that the person is not relevant when they are in their own room, but become relevant if they happen to stray into the corridor, will not protect those at risk.

If fire authorities accepted this principle, we could simply have walked away from undertaking home fire safety visits, and hundreds of people would not be alive today. The only issue for enforcers is who is the most appropriate authority to take action if the owner of a premises refuses to consider them. The fire/housing protocol attempts to cover this dilemma.

To conclude, we accept that retrofitting sprinklers is unlikely to be cost-effective and that other fire precautions need to be considered. However, there can be no excuses in new buildings, designed to house our most vulnerable people, for loss of life due to fire, regardless of whether the Fire Safety Order applies or not.

And if readers think that we are biased towards sprinklers, then they are right, and we make no excuses for being so. Where sprinklers have been fitted, fire deaths have almost been eliminated, injuries and property damage have both been reduced by over 80%, and there have been huge improvements in firefighter safety and significantly less damage to the environment. Need we say more?

Iain Cox
Chairman, National Fire Sprinkler Network

Transient smoke layer hazards in SHEVS

THE ARTICLE by Simon Lay describing the design of the Highcross shopping centre in Leicester (Fire Risk Management, February 2009, p.32) was of great interest. My purpose in writing this letter was prompted by one particular point which carries wider significance.

Mr Lay states: ‘Computational fluid dynamics (CFD) studies revealed that, while the steady-state solution may be acceptable, there was a sustained, transient period where the smoke layer had not fully formed, and there was potential for significant smoke to enter the main mall escape route.’ The observation quoted above is supported by results using two different models developed by International Fire Consultants Limited (IFC).

The IFC models are spreadsheets following the iterative algorithm suggested in Annex B of BS 734-5: 2005. One model, AXIFIL, describes a scenario where the fire is directly below the smoke reservoir. This gives geometries typified by supermarkets and exhibition halls. The other, SPILFIL, describes an atrium-like scenario with a fire in a side room, emitting smoke into a large space. This geometry is typified by multi-storey shopping centres.

Both models are best described as deterministic iterative multi-zone models. Note that neither is a CFD model, so the similarity in findings confirms that similar predictions are unlikely to be artefacts of the models used by Mr Lay or ourselves.

The observed behaviour is typified by the accompanying figure, showing layer height against time and layer average temperatures (above ambient) against time for a generalised supermarket. If a safety criterion of 3m clear beneath smoke is adopted by analogy with BS 7346-4, it can readily be seen that smoke is deeper between 150 seconds and 240 seconds after ignition, before rising to meet the asymptotic value corresponding to a steady-state solution.

It appears that an important factor producing such a result is the delay in initiating the smoke and heat exhaust ventilation system (SHEVS) – as is commonly done to allow a quick search to confirm either a fire or false alarm (that is, when there is an investigation phase in the fire alarm sequence). It is important that we should not overreact: many scenarios will not show this transient unacceptable layer depth, whereas others can be ‘engineered out’. Qualitatively similar behaviour has been observed when using the SPILFILL spreadsheet.

This suggests that there may be previously unrecognised hazards in adopting an investigation phase, and that such a phase should never be adopted without modelling that scenario for transient deepening.

Howard P Morgan FIFireE
Principal engineer,
International Fire Consultants Limited

Political correctness is overriding service professionalism

OVER THE past few months, I have read a number of articles and letters about the current levels of operational competence and leadership in the UK fire and rescue service, all of which appear to have an underlying theme.

The 2002 Bain Report and subsequent ‘modernisation’ agenda have provided a highly fertile area for the Government to use the service as a social engineering playground, the consequences of which are now having an adverse impact on standards and service delivery.

Take, for example, the subject of recruitment and appointments. While the Bain Report made some useful recommendations on these subjects, these have not been translated to the benefit of the service. Indeed, we have the paradox where recruitment standards have been ‘dumbed down’ in the apparent interests of equality and diversity while, at the same time, according to Bain, attempts are supposed to be made to attract people with good educational qualifications to enable them to progress and meet the future needs and demands of the service.

Given the standard of technical knowledge now required by the modern firefighter, there is every justification for insisting on basic educational qualifications as a prerequisite. This should not present a problem, given the large number of applicants who wish to join the profession. Virtually all the support staff posts demand certain qualifications for appointment, and yet the same does not apply to the main core of employees.

The bureaucratic Integrated Personal Development System was applauded by Bain, yet we have not only seen the demise of the examination system but also a marked decline of technical knowledge and operational standards, which is clearly unacceptable. What other ‘profession’ does not insist on formal examination qualifications for its staff? This decline has been compounded by the undue time spent on community fire safety which, while laudable, has been to the detriment of soundly based basic and continuation training, especially at a time when we have seen a marked increase in firefighter deaths and injuries.

Another example of the political correctness overriding profess-ionalism relates to middle and senior appointments. Clearly, the Government shares the misguided views of Bain and demonstrates little or no faith in the current management of the service when it finds it necessary to encourage the direct employment into the higher echelons of the service of people with no experience or under-standing of firefighting. It is interesting to note that in the police service, the Government considers it vital that all middle-ranking and senior officers must start in the rank of constable, to enable them to gain a full understanding of frontline operational policing through direct experience and, if they wish to advance, they need to demonstrate proven policing experience at all levels. Similar principles are not considered necessary in the UK fire and rescue service.

All of this is a sure reflection of the low esteem in which the Government now holds the fire service. The service is currently blighted by too much change that is ill thought through, a target-obsessed culture, and statistics, instead of ensuring that firefighting response and professional standards are developed and improved. Far too many good officers have now lost the will to speak out and highlight the deficiencies.

Of course, there are thousands of dedicated officers and firefighters who are still driven by an overriding sense of duty. However, a generalisation of absurd political correctness, government-enforced targets and toadying to ministers has led to a serious collapse in standards and morale, which needs to be addressed by strong leadership and vision.

Dave Collins
Group manager

Fire protection of archives

IN REFERENCE to the recent article ‘For the record’ by Clark Preistley (Fire Risk Management, March 2009, p.53). Discussing deep-seated fires in paper archives, the second paragraph uses the example of a bonfire, and tells us that a bonfire ‘typically smoulders – material is burning but little external flame is visible’.

Surely this is not so: in such a fire there is flaming combustion, otherwise the combustion propa-gation would be of the orders of millimetres per minute. So, once ignited, a bonfire would continue, without replenishment of fuel, for days or even weeks.

What the article might profitably have mentioned is fire protection by means of a reduced oxygen level in the room. This can be achieved by recirculation of the air through a membrane, from which it emerges with a lower proportion of oxygen and consequently a higher one of nitrogen.

Such devices are in use at a number of very valuable book collections including, I understand, the British Library book storage facility in West Yorkshire. Not only can paper records be protected by this method; it is sometimes used at IT facilities where the destruction of computers by fire would result in the loss of important information.

J C Jones FIFireE
School of Engineering, University of Aberdeen