By Christopher Marrion, PE, FSFPE
From the March/April 2015 issue
Fires are an inherent problem in historic structures, and they continue to destroy the cultural heritage on a local and global basis. In recent years, fires have induced great losses in cities such as the recent fire in Lijiang (China), in structures including the recent loss of the Institute of Scientific Information on Social Sciences (Inion) in Moscow, as well as ships like the Cutty Sark, bridges including the famed wooden Kapelbruk Bridge (Switzerland), monuments including the Namdaemun Gate (South Korea), and trees including the fifth oldest tree in the world in Florida, nicknamed the Senator. Fires are also prevalent following earthquakes and other events, and can cause significant damage that can even exceed that produced by the initial earthquake.
Whether of significance to a local community or on a broader, global basis, historic structures including those buildings of sufficient age, possessing a relatively high degree of physical integrity remaining to how it was initially built, need to be further protected from the fire challenges they face.
A significant amount can be learned by studying fire related disasters. This includes what contributed to these losses, why and how the fire was able to grow, develop, and spread to a significant magnitude, what failed, and what worked. There is also a significant amount that still needs to be learned such as with evacuation and human behavior, and reducing risk to life. Understanding the past in this sense will help better prepare fire disaster mitigation plans to prevent fires, and limit their damage.
Common themes begin to emerge when looking at case studies of past fire events regarding what went wrong and resulted in disasters. These include the following conditions:
Ignition Sources. Numerous ignition sources for instance are typically present. These include poor electrical wiring, lighting, temporary electrical wiring, incandescent/high temperature lighting systems, space heaters, and cooking equipment, as well as open flames, candles, butter lamps, and intentionally set fires.
Combustible Materials. In historic buildings, there is a lot of combustible wood construction and interior finishes, as well as combustible furnishings, contents, and storage throughout that has accumulated over the years. These materials give rise to fast growing fires that can be quite large and last for extended periods of time due to their quantity.
Fire Detection. Fires in historic structures are often then able to grow undetected, as there is typically no automatic fire detection system to detect fire and expedite notification to appropriate personnel. At times, old fire alarm systems may be present. These may have limited detection throughout the building, and may not be maintained over time so may not be functioning. Delays in detection lead to delays in notifying not only occupants but also first responders—allowing the fire to grow significantly.
Notification. It is important to communicate to the occupants, whether the general public or on-site staff, about a fire and what to do. Similar to detection, these systems are often not present or have not been maintained, so they are no longer functional.
Compartmentation. Limited compartmentation and penetrations in fire separations contribute to the ability of fire and smoke to travel and spread beyond the area of origin. This occurs through door openings with doors that are blocked open or had been removed, through unprotected openings such as large open stairways, or through electrical/mechanical equipment penetrations that may be substantially larger than what is required—and then not properly sealed.
Automatic Suppression. Fire suppression can be achieved through automatic means (e.g., sprinklers, water mist) in order to help keep a fire from growing and spreading. In historic structures though, these are typically not present. There is often the fear of having these in an historic facility due to the potential for leakage. One needs to understand the integrity of these systems and that they are monitored for waterflow, whereas often the case people allow plumbing and drainage pipes that run throughout which are less robust and not monitored.
Firefighting. Whether fighting a fire with the local fire service, extinguishers, or a glass of water, it is important to begin extinguishment as soon as possible before the fire has a chance to grow large. In fighting fires, local fire departments have very limited manual suppression capability due to limited equipment and resources for many cultural heritage sites.
Once a fire gets to a certain size, even fire departments from the largest cities would not be able to extinguish these. It is therefore important to detect and extinguish fires while they are very small. It is thus important to be able to notify first responders, provide adequate access onto the site and into the building, provide resources including water, and access to varying sides of the building.
Renovation. Further exacerbating the challenges are fires that occur during restoration and renovation. This is due many times to new ignition sources, hot work, temporary equipment, and combustible construction materials introduced on site at times when the fire protection systems may be under renovation as well, and hence not in service.
Management/Awareness/Training. Fire safety awareness, education, and community involvement in fire or disaster mitigation activities are often limited. This furthers the potential hazard for a fire to start and limits the ability of stakeholders to provide valuable assistance when needed.
How To Better Protect Heritage
There are means and methods, however, available to help develop appropriate prevention and mitigation measures. One of the more beneficial means is by applying a risk informed approach. Multiple benefits arise, including:
- minimizing aesthetic and visual impact to the structure, contents, and historic fabric;
- incorporating effective fire protection provisions;
- meeting intent of prescriptive codes;
- using traditional materials/skills;
- using local knowledge systems;
- being more sustainable;
- increasing local awareness/building capacity; and
- developing maintenance/monitoring strategies for reducing risks to cultural heritage.
Whether protecting a 300 year old Buddhist monastery in Mongolia or Nepal, or looking to protect St. Patrick’s Cathedral in New York City, the approach and objectives may be the same. However, the fire and life safety systems and features used to supplement the approach can be drastically different, including for example the use of conch shells versus voice alarm systems; wool blankets versus sprinklers; or fire watches versus automatic detection.
By addressing these concepts though, facility management professionals can take significant steps to mitigate fire risks and help prevent fires from occurring in their facilities—or at least limit their ability to develop and spread.