CH 4 FIRE SCENE OPERATIONS Flashcards
Life saving operations are placed ahead of firefighting when
Sufficient firefighters are not available to do both, as is the case when no ladder company is on the scene
The best life saving measure may be a
Prompt attack on the fire which if allowed to spread would trap occupants
A life hazard visible on arrival
Must be addressed
However immediate rescue attempts by the 1st arriving engine company without simultaneously stretching and positioning a hose line should be attempted
Only in extreme situations
Factors impacting on the decision to attempt an immediate rescue include
- Safety team complied with
- Occupants endangered by being in the immediate vicinity of the fire
- Number of persons trapped
- Occupants threatening to jump
- Means of egress cut off by fire
- Ability to reach occupants with portables
- Anticipated arrival time of 1st due ladder company
- Staffing level of the engine company (4 or 5)
An accurate and complete size up must include consideration of the following strategic factors
Time of day Life Area Height Construction Occupancy Location and extent of fire Water supply Street conditions Auxiliary appliances Weather Apparatus and equipment Exposures (6 sides of the fire)
Actions that the officer of the 1st arriving engine company can implement to protect endangered occupants include
- Position a hose line between fire and endangered occupants
- Verbal instructions & assurances to the occupants
- Close doors to limit spread of smoke
- Ensure that the incoming units are informed of the location of endangered occupants
Depending on the engine staffing one member may be
Released from the stretch and proceed to the roof to provide vertical ventilation over the stairs
When the exact location of the fire has been determined it
Must be conveyed to the other units operating on the scene
3 stages of fire suppression
Locating
Confining/Controlling
Extinguish
Stages of fire growth
Growth Stage (incipient) Fully Developed (free burning) Decay (Smoldering)
Growth stage (incipient)
*Increases from small flames to full fire
*Takes several seconds to several hours
Rollover potential
Fire growth is dependent on (COSI)
Combustible content (Fuel Load)
Oxygen supply (ventilation openings)
Size of room
Insulation of room
Roll over serves as a warning that the area
May Flashover
Fully developed stage(free burning)
Entire room and its contents are involved in fire
Decay stage (smoldering)
As available oxygen is consumed the fire moves into the decay stage
Potential for back draft exists
Warning signs of possible Back Draft
- Heavy dense smoke with no visible flame in a tightly closed occupancy
- Black smoke pushing out around closed doors or window frames
- Glass stained with smoke condensation and pulsating from the pressure of the fire
- Reversal of air movement pulling smoke back into the building through a doorway
The progression of modern content fires differs from the traditional fire development curve as follows
- Incipient
- A rapid growth stage that consumes the available oxygen vert quickly
- Since modern content fires RAPIDLY consumes the available oxygen within the fire area, they enter into an EARLIER oxygen limited Decay Stage when compared to Legacy fires, and will remain in the Decay Stage if no additional oxygen is added to the fire area
- If additional oxygen is added to the fire area, a second rapid growth stage may be encountered
- A second decay stage will occur as the fuel load is depleted or the fire area is extinguished
A rollover occurs in what stage of the fire
Growth Stage
The Incipient stage is defined as
The early stage of fire development where the fires progression is limited to a fuel source and the thermal hazard is localized to the area of the burning object
The Growth Stage is defined as
The stage of fire development when the heat release rate from an incipient fire has increased to the point where heat transfers from the fire and causes the combustion products to pyrolyze adjacent fuel sources. The fire begins to spread across the ceiling of the fire compartment (rollover)
The Rollover is an indicator that the fire conditions are
Rapidly changing
Backdraft’s will occur in the
Decay Stage
The fully developed stage is defined as
The stage of fire development which has reached its peak heat release within a compartment. This usually occurs after FLASHOVER, resulting in floor to ceiling burning within the compartment thereby creating heat conditions untenable for members.
NOTE: As modern content fires rapidly consume the available oxygen, the fire can go into an EARLY decay stage PRIOR to reaching full development. The interior conditions are pre-heated, smoke filled and oxygen deficient. As additional oxygen is added to the interior, a ventilation induced flashover can occur, resulting Qin rapid fire development
