Search and rescue operations in high-rise buildings present significant challenges for fire departments. Traditional search methods used at residential house fires are often impractical in large, complex structures.
Locating trapped victims in high-rise buildings can be difficult and time-consuming, as searching a building with multiple units across several stories can take considerable time. Additionally, building occupancy levels often exceed the resources available to fire departments, necessitating exploring alternative strategies.
Building design plays a crucial role in protecting those who cannot evacuate. Compartmentalization provides time for firefighters to arrive and extinguish the fire, thereby stopping smoke production. Smoke travels through hallways, lobbies, and stairwells, claiming lives in areas far from the fire. Firefighters act as smoke-fighters during high-rise fires.
Let’s explore the different scenarios, examining smoke spread through the building’s three standard compartments.
The fire is contained within the unit of origin, known as compartment one. No smoke has migrated to the hallway. Firefighters arrive on the fire floor and clear the hallway of occupants before performing an aggressive fire attack.
Once firefighters enter the fire compartment, smoke will filter into the hallway, referred to as compartment two. If the fire is extinguished quickly and the building operates as designed, firefighters will conduct a primary search of the fire unit. If a victim is located, firefighters will transport the victim down one floor via the stairs to a crew position with medical equipment.
Crews will clear the smoke from the hallway via the fire unit or designed hatches. Other occupant units on the fire floor should remain smoke-free if their doors are not opened. Once the smoke lifts, a secondary search is conducted. After the smoke is cleared, wellness checks are performed on all other units using a carbon monoxide detector.
The fire is contained to the unit of origin (compartment one); however, the unit’s automatic door closure did not function properly, or something is preventing the fire unit door from closing completely. Smoke and heat are now present in the common hallway (compartment two). Firefighters are forced to use the standpipe outlet on the floor below the fire floor.
Unfortunately, this will inevitably allow smoke into the stairwell (compartment three) when the stairwell door to the fire floor is propped open for firefighting hoses. We are now on the clock to extinguish the fire rapidly. The hose line extending downrange to protect life and property is the same line that is propping open a door, threatening life and property.
Smoke is the killer in most fires. Smoke will continue to leave compartments one and two and contaminate compartment three, the stairwell. The longer the fire can burn without compartmentalization control and extinguishment, the more smoke spreads throughout the building.
Compartment three is the most fragile compartment. Stairwells are connected to all other floors and compartments and are used by both firefighters and occupants. When firefighters work in a smoke-filled stairwell wearing full PPE and facing zero visibility, they become slower and fatigue quickly.
The spread of smoke within a structure significantly complicates emergency response operations by increasing the number of individuals at risk.
Brent Brooks
This phenomenon can be termed “the building is awakening,” which indicates heightened activity; as smoke propagation intensifies, so does the complexity of the incident. This scenario raises immediate life safety concerns, as smoke migrates rapidly and creates substantial challenges for evacuation processes and those choosing to shelter in place.
Evaluating occupancy numbers during a fire situation is crucial, as they can significantly exceed the number of available firefighters. Rescuing just one person may require two to four firefighters, complicating the balance between rescue operations, smoke containment, fire suppression and evacuation. Overemphasizing one aspect can adversely affect the others.
We can keep occupants safe during a fire emergency by using the building’s public address system to instruct them to either stay in place or evacuate through a clear route. If the building has a Positive Pressure Isolation (PPI) system installed in the stairwells, firefighters may still need to supplement it with their fans. Smoke curtains can help contain smoke as firefighters transition from one compartment to another.
Firefighters typically concentrate their operations in one stairwell, allowing all other stairwells to be utilized for evacuation. Having only one stairwell in a building is inadvisable, as it complicates firefighting efforts.
Brent Brooks
In the past, for scenario two, our standard protocol was to conduct a primary search of each unit, the elevator lobbies, elevator cars, hallways, and stairwells. When performing a systematic search, we would open the doors of units on the windward side of the building and find the occupants safe. However, on the downwind side, upon opening the doors, smoke would quickly fill the unit, putting the occupants at risk. Even if we found people, we could not safely evacuate them since the hallways and stairwells were filled with smoke.
Force-opening doors and searching every unit during a rescue operation takes considerable time. This can slow down or even prevent a thorough search. Firefighters have limited time to complete their search before they are required to exit due to their depleted SCBA bottles, which can be a problem if the search is not completed.
Now that we better understand building science and have studied our past fires, we no longer search closed doors during the “primary” search. Instead, we focus on common areas such as elevator lobbies, hallways, and stairwells, where most high-rise deaths occur. Completing a search has become more achievable than before.
Three firefighters use a thermal imager to search the hallways rapidly. They move from one end of the hallway to the other, shoulder to shoulder, as fast as they can walk. This technique is called “snow plowing”. Firefighters can bypass closed doors to prevent the occupants from exposure to toxic smoke. It is important to note that occupants do not have skin or lung protection; hence, their safety is paramount.
The fire is influenced by wind conditions and may be challenging to extinguish, particularly if a lithium-ion battery is in a runaway state. As the wind over pressurizes the fire unit, it pushes smoke into the other compartments. Additionally, the movement of firefighters and occupants can exacerbate the situation by distributing smoke from one compartment to another. The situation’s complexity will likely increase the longer the fire burns.
The real trick to search and rescue is being prepared with a hose and nozzle package that provides a rapid knockdown with rapid cooling.
Brent Brooks
This rapid knockdown reduces the search area scope, allowing for better use of resources. The faster the fire goes out, the less water damage is done. We can search faster when we stop the smoke production. You have one good chance to stop the spread of smoke. Do this with a high volume of water and stream reach. The occupants without shin and lung protection will welcome it. High-rise firefighting operations are complex; however, we can uncover solutions by studying past incidents and exploring various perspectives.
