Fire behaviour & FF safety Flashcards
how does the body lose heat?
convection, radiation, evaporation, conduction
name the types of heat stress
heat exhausation,
heat syncope (fainting),
heat stroke
what are some ways to control heat stress?
info & training
health monitoring
acclimatisation
aerobic fitness
hydration/nutrition
dressing down procedures
achievable briefs
duration of BA work reduced
individual risk assessment
BA welfare log
rehydration (1L inside 60 mins)
accelerated cooling/rehab vehicle
what is the purpose of the BA shuffle?
to provide a safe system of moving through a hazardous environment (obscured visibility/heath) whilst searching for casualties and/or firefighting
what are some hazards you may encounter when working in smoke and darkness?
uneven ground
changes in floor level
holes in floor
furniture
electricity
sharp objects
USE THE BACK OF HAND TO TOUCH OBJECTS
what are the stages of fire development?
initial fire
developing fire
flashover
fully developed fire
decay
extinction
why is oxygen/ventilation important to control?
as oxygen levels drop the flaming combustion eventually stops, but smouldering/incomplete combustion remains, this causes an INCREASE in unburnt products of combustion and fire gases
so visibility is poor, and more unignited flammable gases exist in a compartment
when a door or window breaks or is opened, the fire will increase in intensity and return to flaming combustion
how does the position of fuel in a room affect the fire?
fire in the centre of a compartment or in open air has 100% fresh air available
fire against a wall has 50% of the air available to it
fire in the corner of a room has 25% of fresh air available to it
how does the compartment size affect heat dispersal?
a larger compartment will take longer for it’s average temperature to rise
a compartment with high ceilings may increase the distance from the hot gases at ceiling height and other combustible materials at ground level
wall/ceiling insulation also affects heat disperal
name the phenomena of fire progression
flashover
backdraught
fire gas ignition/explosion
wind driven
what is a flashover?
a sudden and sustained transition of a growing fire to a fully developed fire
plentiful supply of oxygen, heat and fuel
ventilated compartment
tongues of flame visible in smoke layer
high neutral plane moving down
sig. thermal radiation from above
surfaces giving off visible smoke and gases (pyrolysis)
a rapid increase in compartment temperature
name control measures for a flashover
door entry procedures assessment
gas cooling techniques to cool, reduce and dilute
cooling of combustible items showing signs of pyrolysis
what is a backdraught?
a backdraught is a ventilation reduced ignition of fire gases leading to a sudden deflagration*
*rapid burning of fuels
heat, fuel, insufficient oxygen
under ventilated compartment
fire gases pulsing out from gaps
windows blackened with no visible flames
pressure evident when door is opened
whistling noises
low neutral plane
dense smoke with no visible sign of flames
name control measures for a backdraught
tactical ventilation to induce a potential backdraught in a safe way…BUT NOT if a saveable life exists within the structure
> door entry procedures can be used to mitigate the conditions prior to entry
> gas cooling techniques to cool, reduce and dilute
> use of a TIC to identify seat of fire and temps
> consider a safety withdrawal
> consider defensive firefighting tactics
Name the fire classifications
Class a - ordinary combustible fire (water and foam)
Class b - flammable liquids - foam
Class c - flammable gases - isolate at source, extinguish secondary fire
Class d - metal fires - type d powder
Class e - electrical fires - isolate at source, extinguish secondary fire
Class f - cooking oil fires - fire blanket