PN793 Compartment firefighting Flashcards
What might happen in a compartment fire that is
un-vented and oxygen starved, when the compartment is ventilated by a BA team?
Backdraught.
The resulting deflagration (explosion) will expand following the ventilation pathway to open-air.
What can build up and collect in areas of a building with there presence not being obvious during a fire?
Explosive atmospheres and fire gases.
(If these are in the correct concentration and when exposed to a source of ignition these can ignite causing an explosion even after the primary fire has been extinguished.)
What should a firefighting jet compromise of when entering a compartment?
45mm hose-line with branch set at 230lpm.
What is the principal purpose of the second firefighting jet?
To protect access and egress from a compartment.
A second fire fighting jet should be provided as soon as possible what is its makeup?
45mm hose-line, branch set at 230lpm and at least one length longer than the firefighting jet.
In a compartment that is adequately ventilated a sudden and sustain transition of a growing fire to a fully developed fire is known as what?
Flashover.
What will the application of water within a fire compartment produce if the fire compartment is over 100°C?
Steam.
What is the purpose of a covering jet?
It should be used outside of the compartment to extinguish flame, un-burnt products of combustion and protect surrounding risks.
What should covering jets not be used for?
They should not be used to spray directly into openings.
(This can push flames and products of combustion back into the compartment also inducing a quantity of fresh air. This can increase fire intensity.)
What should the IC conduct prior to any compartment fire-fighting?
A 360° survey.
What is the 360° survey looking for?
Possible life risk.
Extent of fire.
Smoke behaviour.
Entry/exit points.
Potential ventilation outlets.
Who should the IC consult with before making a decision that affects the operation of a fixed installation or building system?
’Responsible person’ or Fire Safety Officer (FSO)
What other sources of information should be investigated before compartment firefighting commences?
MDT
Automatic fire alarm panels
P.I.B
Building occupiers or building signage.
(Information such as access, layout, water suppliers and options for tactical or mechanical ventilation.)
What should BA teams be briefed on before being committed?
Number and locations of any persons reported.
Location and extent of fire.
Nature of occupancy.
The route and task involved to gain access to compartment.
What should happen to hose lines before teams are sent to commence firefighting?
Hose lines must be charged, branches and watersupply checked by opening for several seconds and checking branch flow and jet patterns.
