Chapter 13 Flashcards
131
Fire triangle ends
oxygen, fuel, and heat
131
What is the limiting factor that must be present for fires to grow in a residential house fire?
the limiting factor is the oxygen
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The fire tetrahedron
Oxygen, Heat, fuel and Chemical reaction
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What role does the chemical reaction have in fire
It’s feedback loop that propagates the fire. The chain reaction provides the heat and gaseous fuel generation necessary to maintain fire.
133
Where are CO explosions or cockloft explosions mostly found?
in row homes with common cocklofts
133
Every fire is impacted by ____ and the results can be either positive or negative?
ventilation
135
What is rollover/flameover?
the condition where unburned fuel pyrolysate from the originating fire has accumulated in the ceiling layer to a sufficient concentration that it ignites and burns.
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Pyrolysate
unburned fuel
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What makes rollover so dangerous?
the increase in flame and heat production as well as the ability of the fire to hide.
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How does the adage of not passing fire apply to roll over?
it applies much the same, need to cool the environment (not that he actually come out and says this)
136
flashover Dan Madrzykowski of NIST
Transition phase in the development of a contained fire in which surfaces exposed to thermal radiation, from fire gases in excess of 1100 degrees reach ignition temperature more or less simultaneously and fire spreads rapidly through the compartment.
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what ignites in flashover?
everything in the room, not just gases and temperatures soar past 1000 degrees.
136
What is the difference between a room on fire and a flashover in a room
the difference is flashover room lights up all at once due to the radiated temperature of the room.
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What is a backdraft?
an explosion
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At what stage of fire does back draft occur?
during the decay phase, when the fire has consumed all the available oxygen, but fuel and heat are still present.
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What are the important aspects to remember about back drafts?
- They are explosions
- Introduction of oxygen will set off the explosion
- recognizing fire is in decay, paired with unusual smoke smoke conditions, are signs of backdraft
136
Four major issues affect the change we see in the rapid progression of fire in residential structures:
- Construction methods
- Fuel composition
- Firefighter actions
- Science
137
What change in modern home has contributed the most to rapid fire spread?
Open stairs, which act as chimneys, allowing smoke and flame to travel vertically unimpeded.
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How fast did fire spread up the stairs at the Cherry Rd incident in DC?
18mph
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What are the tactics that can aid firefighters once fire does reach the stairwell?
- when operating above grade, all windows must be laddered.
- Coordinate ventilation and consideration for the actions that make that possible?? control doors
- Identify and announce location of stairwell (to engine company).
- Do not operate on the stairwell, get up or get down (its a chimney and escape route).
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What are the construction methods that aid in fire growth and spread?
- Open Stairs
2. Age of home old or new construction.
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What are construction methods in older homes that contribute to fire spread?
- Ballon frame construction, that allows fire to quickly travel from the basement to the attic, possibly hidden, through void spaces.
- Knee walls, in older homes that create large void spaces for fire to travel in areas that are often full of fuel for the fire.
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What about newer construction homes what are the concerns?
Newer construction methods, outside of open stairs, restrict the movement of fire and smoke quickly. however the concern is with the materials that are engineered and not robust when subject to fire conditions, causing early failure.
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What do modern furnishing represent compared to legacy furnishings?
Modern furnishings have much more stored energy in comparison to legacy furnishing. This creates a dramatic uptick in the rate oaf heat release that can built to flashover much more quickly. This is a danger to everyone within the structure.
