Following the rules for fire protection in historic buildings, with good expert advice, would avoid many headaches.
By Jaime A. Moncada*
Two recent fires have highlighted the importance of protection against confiscations of historic buildings, I refer to the fires of the Cathédrale Notre-Dame de Paris and the Museu Nacional in Rio de Janeiro. However, they are neither the first cathedral, nor the first museum to burn in flames, nor will they be the last.
Fire of the Natural History Museum of Rio de Janeiro (photo): On September 19, 2018, before 7:30 p.m., when it was already closed to the public, a fire broke out in the most important natural art museum in Latin America. Quickly the museum burned down completely. What is known about this fire can be summarized as follows1-2:
• 92.5% of the 20 million historical artifacts housed in the museum were consumed by flames, perhaps the most important collection of natural history in South America.
• A few days before the Notre-Dame fire, the final fire report prepared by the Brazilian Federal Police was handed over to the public.
• This report concluded that the fire had started in a superheated air conditioner in a basement that cooled the museum's auditorium. This equipment had been electrically connected without following the manufacturer's recommendations.
• The fire lasted six hours and during it the firefighters had problems with the fire water supply, as the two hydrants closest to the building had very little pressure and water flow.
• The smoke detection system did not operate and the museum was not protected with sprinklers or fire hoses.
• The museum had severe budget deficiencies.
Notre Dame Cathedral Fire: On April 15, 2019, at 6:20 p.m., this fire occurred that captivated the whole world. Although Notre-Dame's investigation has not concluded, the possibility that the fire was intentional has been eliminated and a short circuit, possibly at the base of the iconic spire, is believed to have caused fire3. Several technical news about the fire have been reported4 5 6 that I would like to emphasize:
• This building had approximately 6,100 m2 of built floor. The iconic spire is 91.4 m high and the attic is 96 m long, 48 m wide and 43 m high.
• The attic (see attached photo) is a tangle of wooden structures that support the roof, called "The Forest" by those who work there. Although the roof structure has been repaired several times, most recently in the nineteenth century, the wooden beams have been reused and many date from 1160 to 1220.
• The building had an alarm and smoke detection system, but there were no fire walls or automatic sprinklers.
• The first fire alarm, possibly from a smoke detector, reported to the panel at 6:20 p.m., 25 minutes before the Cathedral closed its doors.
• At that time the public and staff were evacuated. Someone went to investigate the attic and did not find the fire.
• At 18:43 a second fire alarm reports to the panel, but this time the fire was found in the attic.
• At 18:55 the fire was already visible outside the Cathedral; at 7:56 p.m. the needle collapsed; and at 3:40 the next day, nine hours after the fire started, it is declared off.
• During the extinction about 400 firefighters worked, drones with cameras were used, a remote-controlled robot with a 660 gpm7 water cannon, and water flow was added to the island's hydrant network, pumping through hose lines from the Seine River.
• At the time of the fire, a €6 million restoration project was underway that sought to reinforce the iconic spire and repair some of the beams in the attic.
Regulations: NFPA has two standards that regulate fire protection of historic buildings. NFPA 914, Historic Structures Fire Protection Code and NFPA 909, Code for the Protection of Cultural Resources such as Museums, Libraries and Places of Worship. Although there are no statistics on how many historic buildings are destroyed by fire, there is only information on the most relevant fires, such as the Museu Nacional or Notre-Dame. However, the issue of fire safety in historic buildings is a topic that has had much discussion in recent years.
Obviously, all these buildings were built when there was no adequate building code, with combustible materials, without any fire system and with very limited evacuation routes. The repair and restoration process further increases the risk of fire, by introducing hot work and flammable materials. In addition, when thinking about improving the fire safety of the building, there is resistance because the possible modification to the interior finishes and architecture of the building contravenes the "historical" nature of the structure that is what you want to preserve. The issue is simply very complex.
The existing regulations do not focus on establishing prescriptive requirements, such as those found in a modern fire code, but rather suggest that fire safety consultants, with the support of the maintenance team and the building's curators, develop an assessment that seeks effective and cost-beneficial solutions. A good idea is to focus on ignition sources, for example:
• Prohibit smoking.
• Modernize the electrical system.
• Prohibit the use of electrical extensions.
• Prohibit/restrict the use of candles.
• Prohibit the use of portable heaters
• During renovations, if there are hot jobs, establish a pre-work permitting process. The person in charge of these permits must inspect, at the end of the day, all areas where they executed hot work.
• Use retardants on combustible surfaces.
• Evaluate the use of early smoke detection, such as air sampling detection.
• Evaluate the installation of automatic sprinkler systems. For example, the Notre-Dame penthouse would have been an ideal candidate for such systems.
The restoration of the Cathedral will take about five years and it has also been estimated that it will cost more than one billion Euros, let alone the cost of the artifacts that were lost in the fire and can never be replaced. Adequate fire safety for Our Lady of Paris as well as for the Brazilian History Museum would have cost only a fraction.
Footnote:
1. "A Faulty Air Conditioning Unit Sparked the Brazil National Museum Fire", by Meilan Solly, April 9, 2019, Smithsonian Magazine.
2. www.en.wikipedia.org , National Museum of Brazil/2018 Fire
3. https://mymodernmet.com/notre-dame-fire-updates/, Notre-Dame Updates: What We Know About the Cathedral Five Months After the Fire, September 10, 2019.
4. https://en.wikipedia.org/wiki/Notre-Dame_de_Paris
5. "Notre-Dame Attic Was Known as 'the Forest' and It Burned Like One.", by Aurelien Breeden, Elian Peltier, Liz Alderman and Richard Pérez-Peña, New York Times, April 19, 2019.
6. http://www.notredamedeparis.fr/en/la-cathedrale/architecture/la-charpente/
7. Colossus type robot, manufactured by Shark Robotics in France. https://www.shark-robotics.com/en/robot/colossus/
* Jaime A. Moncada, PE is a director of International Fire Safety Consulting (IFSC), a fire protection engineering consulting firm based in Washington, DC. and with offices in Latin America. He is a fire protection engineer graduated from the University of Maryland, co-editor of the NFPA Fire Protection Manual, Vice President of the Society of Fire Protection Engineers (SFPE). Moncada's email address is [email protected].
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