(Image: Notre-Dame Cathedral before fire (left) and after (right) (Credit: Zuffe y Louis HG under Creative Commons 4.0 International licence))
No. Not dateline Paris 2019 but Paris 1831, an extract from The Hunchback of Notre Dame, first published in that year.
On the catastrophic conflagration at the Notre Dame Cathedral one fire expert was less evocative, but more revealing on the fire’s dynamics. Steve Emery, Oxford University fire officer and formerly fire safety adviser at English Heritage, told Wired that the lead covering the roof would have initially slowed the fire’s growth by preventing fresh air from fanning the flames. But as lead, which melts at 324 degrees celsius, dripped away the wind would have hit the fire, accelerating its spread. The melting lead would have splattered onto other timber beams, enlarging the blaze.
Such complexities of flashover in so ancient a building, with an open volume of 100,000 cubic metres (larger than the Royal Albert Hall), prompted us to seek the opinion of industry leaders as to how our architectural heritage can be protected against fire without damaging the special character of historic sites.
Notre-Dame’s roof of lead sheets over timber frame before the blaze
In the case of molten lead as a factor in fire, clearly the first consideration is to prevent the lead melting. An effective solution to delay fire spread would be to lay sheet-lead on solid board (such as calcium silicate) to act as an insulated infill between the timber roof and its sheet-lead covering to form a fireproof barrier.
Sheet-lead is a traditional exterior weather proofing layer for many historic buildings and often intrinsic to their preservation. A principal approach to reducing risk and protecting historic buildings from fire damage is the application of fire retardant coatings; these can come in various forms for older traditional building materials such as timber and plasterwork without altering the aesthetic of the materials.
Timber and plasterwork treatments are used throughout the UK in heritage buildings. Even buildings with old steelwork can be protected with intumescent paints and coatings with little effect on their appearance. And it cannot be over-emphasised, repair work needs to be carried out with extreme caution especially when welding or burning metals such as lead in roof areas.’
CH Materials is exhibiting at FIREX 2019, ExCeL London, 18-20 June 2019 (stand FX140). REGISTER NOW
Sympathetic to architectural heritage, fire curtains provide historic buildings with an approved fire protection product that can be specified and installed without compromising fire safety regulations. As to the theoretical compartmentation of very large open volumes, fire curtains can contain large areas using fire curtain products with unlimited widths and heights approved to 8 metres, though clearly, in the case of Heritage Buildings, aesthetic considerations are a very real factor in conditioning specification options.
For example, Coopers fire curtains have been developed to remain discreetly hidden within a ceiling, enabling them to deploy and create fire-resistant barriers to prevent the spread of fire and or smoke. To compartmentalise high risk areas, Coopers’ FireMaster fire curtains are installed in the Royal Palaces, the British Museum and Buckingham Palace, ensuring compliance without compromising architecture.
Coopers Fire are Third Party Accredited for product and installation, commissioning and servicing and are trusted to protect occupants, historic buildings and their cultural artefacts from fire.
Coopers Fire is exhibiting at FIREX 2019, ExCeL London, 18-20 June 2019 (stand FX32). REGISTER NOW
Optical beam detection’s advantageous scope for a diversity of open-area applications makes it the ideal, non-invasive detection mode for Heritage installations where building aesthetics are important. For conservationists, discretion is assured since, significantly, due to the fact that there are no connections between the two parts of the Beam, the units can be mounted in areas demanding a low-profile presence.
In the case of FFE’s End-to-End type beams, we have examples of the Transmitters and Receivers being recessed into walls to make them as discreet as existing established fixtures. Theoretically, for an interior’s open span of 130 metres, FFE’s Fireray One Reflective Beam together with the F3000 End-to-End Beam can effectively cover the distance to protect the risk area, requiring possibly a specification of no more than 40 beams, dependent on the geometry of the location.
It’s important to note that, based on the UK Beam installation guidelines, to exceed a height of 25 metres requires what is termed ‘Supplementary Detection’.
This is a layer of Beams mounted at a lower level in the risk area and closer together so they can catch the rising smoke plume. Even with Supplementary Detection, the highest standard height at which a beam can be mounted is 40 metres (but 43 metres can be attained if this height is less than 10 percent of the total risk area). FFE affirms that, beyond the purely architectural considerations of linear smoke detection and its discreet siting for Heritage applications, specifiers recognise the distinct economic advantages of beam detectors in comparison with other detection modes, their space-efficient coverage and the significant advantages achieved by reductions in installation time and detection unit procurement.
FFE is exhibiting at FIREX 2019, ExCeL London, 18-20 June 2019 (stand FX410). REGISTER NOW
Supplementary optical beam detection protects risk area in open volumes of exceptional height
All participants in these observations have highlighted with particular emphasis the dangers of ‘hot work’ during restoration of heritage sites. They point out that if the AFD (Automatic Fire Detection) is disabled, then reliance is placed on those working in the risk area to detect any fires.
Best practice, therefore, is to isolate only the area that is being worked in rather than isolating the whole of the building’s Fire Protection System. For any anticipated hot work a Permit to Work should always be granted by the Client and a Risk Assessment along with a Method Statement should be submitted by the company undertaking the work.
During refurbishment it is not uncommon for hot work activities that produce sparks or use flame to be prevalent when metal is cut or welded, roofing materials laid, or paint removed. Presence of people in normally unoccupied areas can also increase risks from accidental and smoking-related fire sources, as can the routing of temporary power supplies required to run equipment and lighting.
Refurbishment might also require the disabling of installed fire protection systems for a period of time. Control of fire risks on construction sites is well documented, with strict control of methods, training requirements, provision of firefighting equipment and safe systems of work.
These are normally sufficient, but increasingly, where the consequences of a fire are great (financially, historically or a threat to adjacent buildings), it is becoming more commonplace to install temporary detection and suppression systems to cover the periods of heightened risk.
It is often cited that the installation of fixed fire suppression systems, such as sprinklers, are incompatible with historical building fabric preservation. There are actually very many sympathetic installations, and few issues have proved insurmountable – a small compromise to ensure survival for future generations to enjoy seems a small price to pay.
The FPA is exhibiting at FIREX 2019, ExCeL London, 18-20 June 2019 (stand FX250). Dr Jim Glockling is also technical advisor to the Business Sprinkler Alliance – exhibiting on stand FX410. REGISTER NOW
FFE’s Fireray Reflective beams protect Dome of the Rock, Islamic shrine on the Temple Mount, Old City of Jerusalem
In a Converged Security Solution the following opportunities for Fire Prevention, Detection and Response can be realised.
Specifically, Micro Focus IDOL provides AI powered video analytics and data fusion that can be used in potentially the following ways for the detection of fires (accidental and arson):
Vidsys’ Converged Security and Information Management (CSIM) platform is able to pull in alarms/sensors, cameras and any other monitoring associated with the property. So if the alarm sensor went off, it would trigger a situation where the operations centre can respond immediately.
The operations centre can review all nearby cameras to the fire alarm and then figure out what to do next with the automated workflows and action plans.
The Converged Security Centre will run for all three days of IFSEC with different applications case presentations running throughout the day. REGISTER NOW
The problems associated with safeguarding the priceless fabric of ancient buildings are myriad. According to reports from Paris, Notre-Dame’s authorities persisted in a refusal to install a protective fire system in the fragile roof space for fear that electricity to any system would itself spark a blaze.
This natural caution by preservationists demonstrates how complex heritage safeguarding can be for proponents of technological fire protection solutions. Paradoxically, in some cases, even enhanced compartmentation can actually be counterproductive in safeguarding an historic building, with upgrades such as fire barriers often having a damaging effect on the delicate microclimate of a building, upsetting a stable system and allowing the growth of moulds, fungi and rot.
As a contributor to this article reminds us, radical thinking about heritage protection can be confounded by our industry’s real-life case histories. His cautionary tale points to the fact that cathedrals are themselves the repositories of fire and smoke (candles and incense).
“I have experience of churches which let candles ‘burn out’ after a Sunday service and this practice set off the AFD which had been fitted the week before,” he told me. “The Church was not aware of just how sensitive the fitted detection was and did not think that smoke from candles left to ‘burn out’ on a table would be a problem, but in this instance, the candles were directly under the AFD.
“By contrast, I worked in a cathedral where they were aware of the potential of false alarms and wanted to perform a test to prove that the AFD did not pick up the incense which they burned at Easter. They burnt the incense and, when we were content no fire had been detected, we set off a smoke pellet to make the AFD go into fire.”
Amid an intensifying focus on the fire safety of our architectural heritage, technological solutions are under scrutiny. From video analytics to even thermal imaging by drones, no solution should be ruled out, which is why concerned practitioners in fire and security risks are joining the conversation at Europe’s only dedicated annual fire safety event.
Most of the experts and fire protection companies who shared their advice above are exhibiting or presenting at FIREX 2019 (or IFSEC 2019), which takes place 18-20 June 2019, ExCeL London. REGISTER NOW
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Lets all get our Silo hats because we are all better than all the rest are we not! have we as an industry learned NOTHING from recent events!
[…] protection have been springing up everywhere. IFSEC Global Magazine just published an article – Notre Dame blaze: fire experts on safeguarding heritage sites – which addresses the critical areas on how to mitigate the risks of fire to historical […]
[…] protection have been springing up everywhere. IFSEC Global Magazine just published an article – Notre Dame blaze: fire experts on safeguarding heritage sites – which addresses the critical areas on how to mitigate the risks of fire to historical […]