This month, we will be discussing some strategic considerations for engine companies when they arrive at a working fire in a multiple occupancy dwelling. Previously, we had discussed some of the more common issues with multiple dwellings, no matter the size or configuration. We will take a look at how these issues affect the operations of the engine companies on scene.
Engine companies play a key part of the fireground operation. Each of these units has specific responsibilities on-scene, such as:
• Water supply
• Placement of attack and back up lines
• Protection of exposures
• Master stream operations
• Protective system operations
• Property conservation
• Search (Off the hose line)
A primary concern of the engine company is not only location of the fire, but also the extension capabilities that the incident may create. It is important that the engine company members understand and recognize how fire spread may occur, particularly:
• Convection - This occurs through the travel of heated matter, specifically smoke, heated air, and heated fire gases.
• Conduction - this occurs through the travel of heat through a solid body of matter, or conductor of some type. Different materials will serve as better conductors than others, based on density and composition of the conductor.
• Radiation - This allows heat to travel without the use of any material substance whatsoever, and is the toughest to protect against.
• Direct Flame Contact - Flames impinge on materials within the area of burning, and increase the object temperature to its ignition point.
Issues For The Engine Company
One of the most critical issues with multiple dwellings, especially multi-story occupancies, is that the fire load and the victim potential is directly above one another, meaning that the fire can spread quickly and affect victim egress immediately (see Photo 1.) Taking this into consideration, it is vital that control of the stairways and vertical arteries in the occupancy are controlled by the first arriving units. Getting handlines into the stairways is a vital task to protect the occupants during their escape, and control most vertical fire spread. Many times, occupants leave the fire doors at the stairs chocked open, and this allows for smoke and heated gases to spread to upper floors, and cuts off any escape paths that the victims may have.
Engine companies should also anticipate vertical fire spread via pipe chases and void spaces located throughout the structure. Construction techniques result in voids for utilities and pipes throughout the dwelling and can serve as an artery for flame spread (see Photo 2.) One of the biggest voids in the building will be located behind the bathroom wall, in the vicinity of the toilet. This area is used for both the drain pipe and the vent pipe, each going in opposite directions. With multiple units being served by one void, the area will have to be large enough to accommodate its usage. Open this void space and check it thoroughly whenever this area is potentially exposed to fire spread.
Choosing the right hoseline during initial operations can make or break the entire operation. The initial arriving engine company officer has some critical thinking to do: choosing the right size line (diameter and length) and making sure the line can make the required flow to extinguish the fire. But first, the officer needs to know where the fire is, and what stage the fire is in; therefore, location and extent of the fire is considered the most important size-up concern for most officers (see Photo 3.) Fire conditions can dictate the use of either 1 3/4-inch or 2 1/2-inch handlines for needed fire flow, and when in doubt, it is best to go bigger. Reaching the fire area is just as important, so bringing the right amount of hose is critical. There are two schools of thought on this: