Chapter 19

Report
Chapter 19
Fire Suppression
Introduction
• This chapter covers:
– Putting into action the techniques and
methods discussed thus far
– Common types of fires and some common
techniques
– Common elements of fire control
– Tactical considerations
19.2
Elements of Fire Control
• Know the basic principles involved in
processes that create and sustain fire
• Lower the losses and risks:
– Arrive on the scene quickly
– Bring all your knowledge
19.3
Structural Fire Components and
Considerations
• Many factors must be taken into
consideration:
–
–
–
–
Length of time fire has been burning
Building construction materials
Occupancy type and contents
Resources available
19.4
Figure 19-1 The old and new
ways of visualizing the
combustion process, the fire
triangle and the fire tetrahedron.
19.5
Ground Cover Fire Components
and Considerations
• Wildland fire triangle:
– Weather
• Given similar fuels and topography, fires
burn radically differently in different weather
conditions
– Fuel
• Two main variables: rate of spread and
fire intensity
– Topography
• Steepness of slope, drainages, ridges
and saddles all critical to fire behavior
19.6
Figure 19-5 The wildland fire triangle differs
from the structural fire triangle.
19.7
Figure 19-6 The components that
make up the weather side of the
wildland fire triangle.
19.8
Figure 19-7 The components
that make up the fuels side of the
wildland fire triangle.
19.9
Figure 19-10 The components
that make up the topography side
of the wildland fire triangle.
19.10
Vehicular Fire Components and
Considerations
• Number of variables:
– Avoid standing in front of bumper after it is heated
– Any fuel leak in engine compartment can ignite
quickly
– Recognize electric vehicles
– Primary dangers in passenger compartment are
materials used in construction
– Use care around air bags: chance of discharge
– Trunk used for storage of unknown materials
– Underside fuel storage area may be leaking raw
fuel
19.11
Flammable Liquids Fire
Components and Considerations
• Each flammable liquid has its own
specifications
– Solubility
– Polar solvents
– Specific gravity
• Specifications affect burning characteristics
and extinguishment
• Knowing characteristics of a material provides
margin of safety and ability to mitigate the
hazard
19.12
Flammable Gas Fire Components
and Considerations
• Can be grouped with flammable liquids
• Understand hazards associated with
gases
• Properties:
– Flammable range
– Vapor density
– Toxicity
19.13
Process of Fire Extinguishment
• Number of steps must be taken:
– Plan of attack
– Apply plan of action quickly, efficiently,
safely
– Indirect attack
– Combination attack
• Goal is to save property
– Not enough water: fire will not be
extinguished
– Too much water: water damage may
exceed fire damage
19.14
Figure 19-17 The indirect attack has the firefighters
applying a 30-degree fog into the upper heat layer of the
fire in order to create a steam that will extinguish the fire.
19.15
Figure 19-21 If the line selected does not match the size
needed, the fire will burn longer and hotter and can
jeopardize the operation.
19.16
Proper Stream Selection
• Sufficient water must be applied
• Factors:
–
–
–
–
–
Proper stream type
Stream size
Placement of fire stream
Nozzle type
Mobility of stream
19.17
Table 19-1 Hose Stream Characteristics
19.18
Figure 19-22 The first line pulled should be
positioned between the potential victims and
the fire.
19.19
Tactical Considerations
• Priorities: RECEO
• Incident Command System (ICS)
• Tactical objectives:
–
–
–
–
–
–
–
Mental preparation
All factors considered upon arrival
Choose mode of attack and call for attack
Exposure
Confinement and ventilation
Extinguishment
Overhaul
19.20
Figure 19-28 Radiant heat is the main cause
of exposure fires within short distances.
Radiant heat will travel in straight lines from
the heat source to nearby objects.
19.21
Figure 19-29 Fires most commonly should be
attacked from their unburned side, pushing the
products of combustion away from unburned
materials and areas.
19.22
Table 19-2 Fireground Factors
19.23
Residential Occupancies
• Generic considerations:
–
–
–
–
–
–
–
Scan the scene
Order of attack
Rescue occupants
Exposure control
Ventilation
Extinguishment and overhaul
Housing and clothing for occupants
19.24
Table 19-3 Rescue Factors
19.25
Business and Mercantile
Occupancies
• Fought differently than residential fires
– Depending on time of day, life hazard for victims
not as great
– Hazards to firefighter can be greater
– First-in engine goes to front of building
– Second-in engine has numerous options based on
condition of fire
• Injuries come from falls and building collapse
• Hazards associated with products
manufactured
19.26
Multistory Occupancies
• First-in unit goes to control room
• Communication is extremely important
• Gather in stairwell prior to deploying on
fire floor
• First-in truck goes into ventilation mode
• Other arriving units fill important
operational positions
19.27
Figure 19-41 Firefighters must only
use elevators that are secured so
that accidental fire exposure will
never occur.
19.28
Figure 19-42 The high-rise fire is usually
attacked from the stairwells. Laying hose up
from the floor below the fire floor will give the
firefighting team a safer and more efficient
operation.
19.29
Below-Ground Structures or
Basements
• Some of the hardest fires to fight
– Highest temperature is at entry point
– Difficult to ventilate
• First-in engine company goal is to get water
onto fire as quickly as possible
• May need to punch through the floor above
the room
– Flood the room with water or high expansion foam
19.30
Figure 19-45 Firefighters must
travel down through
superheated gases and toxic
products of combustion in order
to fight a basement fire.
Figure 19-46 If access
to the below-ground fire
is too dangerous or not
practical, then other
means must be used to
extinguish the fire
through the ceiling of
the burning room.
19.31
Structures Equipped with
Sprinklers or Standpipes
• Sprinklered buildings create a unique
situation
– Smoke and heat held down by cooling
water
– Enter building without shutting down
sprinkler
• Standpipe system is invaluable
– Carries water
– Saves a great amount of time
19.32
Exposure Fires
• Any combustible item being threatened
by something burning in another area
• Factors involved:
– Wind, distance, material, and intensity of
fire
• Conduction: cooling medium applied to
material being heated
• Convection: downwind patrol ensures
embers do not ignite other materials
• Radiation: apply water to exposed area
19.33
Figure 19-49 Radiation will travel through water or any
opaque material. In order for water to be effective, it must
be applied to the exposed surface in order to cool it.
19.34
Non-structural Fires
• Ground cover or wildland fire
– Confine spread
– Guide fire
– Operate from position of strength and
safety
• Vehicular firefighting
– Be aware of backdraft and flashover
– Attack from upwind and uphill side of
vehicle
19.35
Figure 19-52 An indirect attack on a
ground cover fire with two engines and a
dozer.
19.36
Figure 19-54 Protecting homes in the
interface is a growing practice across the
country for engine companies used to
fighting fire in the cities.
19.37
Alternative-Fueled Vehicles
• Fighting fire in these vehicles is tactically
different
• Flex-fuel vehicles
– Use gasoline and alcohol fuel in any mixture
• Bi-fuel vehicles
– Two separate fuel systems
• CNG and LPG vehicles
– Compressed gas tanks; high pressure fuel lines
• Electric-fueled vehicles
– Procedures differ due to nature of power source
19.38
Establishing Safe Work Areas
• Most vehicle fires found in places of travel
– Block areas from outside penetration
– Place traffic cones or road flares
• Flammable liquids and gases do not follow
basic laws of extinguishments
• Trash fires can surprise the most seasoned
firefighter
• Large piles with large fires in outside storage
areas require large amounts of water
– Water delivery the key to success
19.39
Figure 19-60 To protect firefighters on scene in the street,
the engine is typically used to block traffic. Cones are used
quite often to assist in this endeavor.
19.40
Flammable Liquids and Gas Fires
• The mechanisms of extinguishment
are well known to the fire service
– Smother the fuel, cutting off the supply of
oxygen
– Starve the fuel by removing unburned
material from the area
– Interrupt the chain reaction process with
chemical agents
– Cool the fuel, reducing vapor pressure
19.41
Flammable Liquids and Gas
Fires (cont’d.)
• Can set up generic principles for fighting
most flammable liquid and gas fires as
follows:
– Identify the material involved and its hazards
– Utilize written assistance with the DOT
Emergency Response Guidebook and other
sources
– Evaluate the threat to nearby similar
commodities such as gas cylinders and tanks.
For instance, get water on exposed tanks to
reduce internal pressure buildup and prevent
the possibility of a BLEVE
19.42
Figure 19-63 Water is applied to the heated
metal surface in order to keep it cool, slowing
the pressure buildup inside the exposed tank
car. This will reduce the possibility of a BLEVE.
19.43
Flammable Liquids and Gas
Fires (cont’d.)
• Determine which extinguishment
agent and principle is best
– For small fires, consider CO2 or dry
chemicals
– For larger fires, consider foam suited
for that particular commodity
– For some fires, consider letting the
fire burn itself out
• Be aware of the hazards
associated with premature
extinguishment
19.44
Figure 19-64 A team of firefighters
approaches a flammable liquid fire control
valve behind a fog pattern. (Courtesy of Phill
Queen)
19.45
Flammable Liquids and Gas
Fires (cont’d.)
• Look for shutoff valves or switches to
shut down the flow of material to the fire
– Use two teams of firefighters, one per hoseline
– Each team is positioned approximately five
feet apart so that when the fog pattern is open
the two overlap and remain in constant contact
with the ground, creating a protective wall
– Both teams simultaneously approach the tank
19.46
Flammable Liquids and Gas Fires
(cont’d.)
• Look for shutoff valves or switches to shut
down the flow of material to the fire
(cont’d.)
– Approach the shut off valve that has been
identified slowly
– The fog pattern should overlap the valve which
will allow a member from one team to turn off
the valve while remaining protected
– Once the fuel is cut off the fire should
extinguish and the firefighters should retreat in
the same manner they approached
19.47
Fighting a Fire for Tanks and Other
Containers Under Pressure
• A tank or container can fail at any time
• The dangers associated with a BLEVE are:
– The fireball can engulf responders and exposures
– Metal parts of the tank can fly considerable
distances
– Liquid propane can be released into the
surrounding area and be ignited
– The shock wave, air blast, or flying metal parts
created by a BLEVE can collapse buildings or
move responders and equipment
19.48
Figure 25-60 Diagram of a BLEVE.
19.49
Fighting a Fire for Tanks and Other
Containers Under Pressure (cont’d.)
• Firefighters should withdraw immediately
in the case of rising sound from venting
relief valves or discoloration of the tank
• Fire must be fought from a distance with
unstaffed or unmanned hose holders or
monitor nozzles
• The tank should be cooled with flooding
quantities long after the fire is out
19.50
Job Performance Requirement
25-1
• Fighting a Fire for Tanks and Other
Containers Under Pressure
A A tank or container can fail at any time, and it is
impossible to determine the exact moment that failure will
occur. Firefighters should withdraw immediately when
increasing sound from venting relief valves or a
discoloration of the tank is noticed. In this photo, a highpressure tube trailer carrying compressed hydrogen is on
fire.(Courtesy of Maryland Department of the Environment
Emergency Response Division)
19.51
Job Performance Requirement
25-1 (cont’d.)
• Fighting a Fire for Tanks and Other
Containers Under Pressure (cont’d.)
B Fire must be fought from a distance with unstaffed hose
holders or monitor nozzles. In this photo, a liquid propane
tank has overturned and the propane is being flared
(burned) off before the truck can be righted. (Courtesy of
Maryland Department of the Environment Emergency
Response Division)
19.52
Cylinders
• All cylinders are pressurized
• The pressures range from a low of
200 psi to a high of 5,000 psi
• Cylinder identification is accomplished
through:
–
–
–
–
Labeling
Color coding
MSDS sheets
Intended site use
19.53
Cylinders (cont’d.)
• Cylinder characteristics
– Relief Valves
– Tangible Discs
19.54
Lessons Learned
• Principles of firefighting based on
sound scientific laws and years of
firefighting experience
• Tactics and strategies will differ
• With newer automobile fuels, the job of
the firefighter is constantly changing
• Knowing basic elements of fire control
will result in a better environment
19.55

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