preincidnet preparation. objectives properly calculate required fire flow for structures using the...
TRANSCRIPT
PREINCIDNET PREPARATION
OBJECTIVES
Properly calculate
required fire flow for
structures using the
National Fire Academy
Fire Flow Formula.
FIRE FLOW
REQUIREMENTS
FIRE FLOW
FORMULA
Module 5
Overview
OBJECTIVES
Given the required fire
flow for a structure,
estimate the personnel
required for offensive
operations.
RESOURCE CAPABILITY
AND DISTRIBUTION
DATA
Module 5
Overview
OBJECTIVES
Given a scenario,
properly complete a
National Fire Academy
Quick Access Prefire
Plan
QUICK ACCESS PREFIRE
PLANNING
Module 5
Overview
FIRE FLOW REQUIREMENTS
• Fires extinguished by absorbing the heat with water
• Application of water will:– Absorb heat– Reduce temperature– Extinguish fire
FIRE FLOW REQUIREMENTS
To extinguish a fire , the quantity of water (gpm) must exceed the heat
(Btu’s) being produced.
FIRE FLOW FORMULAQUICK CALCULATION
Basic Formula: Length x Width = GPM
3
CALAULATES THEORETICAL FIRE FLOW
• Large amounts of heat absorbed
• Reduces temperature below ignition temperature
• Fire is “blacked-out” ready for overhaul
WITH HIGH PERCENTAGES OF INVOLVEMENT INTERIOR
OPERATIONS ARE NOT POSSIBLE
• 100% involvement answer is theoretical
• Starting point for realistic flow rate
• Starting point for defensive operations
• Tactical operations must be evaluated
ORIGIN OF FORMULA
Empirical formula developed by NFA
development team.
Study of fire flow at fire situations
BASIC FORMULA
Basic Formula: L x W = GPM
3
Flow for one floor fully involved.
Estimate Length/Width to nearest 10 feet.
Multiply L x W then divide by 3.
Theoretical fire flow for 100% involvement.
Insert 1 story 40’x 30’ structure- no fire
30 X 40
BASIC FORMULA
• Quick calculations at the scene
• Calculates water required for:– Confinement, Extinguishment, Back-up lines
Insert 50’ x 30’ building with dimensions on slide
50x30
MULTIPLE STORIES
Multiply base fire floor by
number of floors
Insert 2 story house
(50 ft X 30 ft /3) x 2 =
FULLY INVOLVED = 1000 GPM
50% INVOLVED = 500 GPM
25 % INVOLVED = 250 GPM
EXPOSURES
GPM = LENGTH X WIDTH + EXPOSURES
3
WATER FOR EXPOSURE PROTECTION
• Interior exposures - floors above the fire on “fire-resistive” construction
• Exterior exposures - buildings or other objects
EXPOSURE PROTECTION
• Up to 4 floors above the fire
• Buildings or other objects
• 0 to 30’ -- usually an exposure
• 30’ to 100’ -- could be an exposure
• 100’ or more -- usually not an exposure
You must make the final determination of exposure based on observed conditions
EXPOSURE PROTECTION
• Fire area adjacent to a fire wall
• Should the exposure become involved - calculate flow as new fire building
EXPOSURE PROTECTION
Exposure “C”
25%
Exposure “B” Fire Exposure “D”
25% Building 25%
Exposure “A”
25%
Exposure Fire Building Exposure
“B” “D”
Base Flow = 1000 GPM
Exposure “B” = 250 GPM (25%)
Exposure “D” = 250 GPM (25%)
INTERIOR EXPOSURE( Fire Resistive Structure)
5 EXPOSURE 25%
4 EXPOSURE 25%
3 EXPOSURE 25%
2 EXPOSURE 25%
1 FIRE FLOOR
EXPOSURE PROTECTION “Fire Resistive” Structure
25%
Exposure
“B”
250 gpm
25%
Exposure
“D”
250 gpm
3 Exposure 250 gpm (25%)
2 Exposure 250 gpm (25%)
1 Fire Floor
Total Fire Flow = 1000 GPMTotal Exposure Flow = 1000 GPMTotal Flow Required = 2000 GPM
PERCENTAGE OF INVOLVEMENT
GPM = L x W + EXPOSURE x PERCENT OF INVOLVEMENT
3
PERCENTAGE OF INVOLVEMENT
Fire Building Exposure “D”
1000 GPM 250 GPM (25%)
100% Involvement = 1250 GPM
75% Involvement = 950 GPM (1250 x .75)
50% Involvement = 625 GPM (1250 x .50)
25% Involvement = 325 GPM (1235 x .25)
Individual Activity 5.1
Fire Flow Calculation
15’ 20’
Fire building is 30’x 50’
Exposure B Fire Building
20’ Exposure D15’
RESOURCE CAPABILITY AND DISTRIBUTION DATA
KNOW INITIAL ATTACK CAPABILITY
• Measured in terms of ability to flow GPM
• If fire flow requirements exceed resources, get help
RESOURCE CAPABILITY AND DISTRIBUTION DATA
• Capability/Distribution evaluation parameters
• Requires an aggressive interior fire attack
150 gpm
INTERIOR FIRE ATTACK FLOW RATES AND
PERSONNEL REQUIRED
Hose size Flow Rates Personnel/Lines
1-1/2” 100 gpm 2
1-1/2” 150 gpm 2
1-3/4” 150 gpm 2
2” 240 gpm 3
2-1/2” 300 gpm 4+
FOUR MAJOR FUNCTIONS ON THE INCIDNET SCENE
• COMMAND
• VENTILATION
• SEARCH
• FIRE CONTROL
Insert building fire 40’ x 90’ slab foundation
“Distribution at simple incidents”
FIRE INVOLVEMENT
1-story structure
40 x 90 (3600 Sq. Ft) built on a slab
25% involvement, no exposures
gpm = 300
Personnel Requirement
Incident Commander 1
Ventilation 2
Primary Search/Fire Attack/
Pump Operation 7
Total Personnel Required 10
Insert 2 story building fire - lot’s of fire-Titled- distribution at complex incident
Distribution at complex incident
60 X 60
FIRE INVOLVEMENT
2-story structure
60 x 60 (3600 Sq. Ft) built on a slab
25% involvement, 1 second floor exposure
gpm = 600
Incident Commander 1
1st and 2nd Floor Supervisors 2
Ventilation 4
Primary Search/Fire Attack/
Pump Operation 4- 1-3/4” lines 12
Total Personnel Required 19
CONCLUSION
gpm divided by personnel = gpm per person
300 gpm divided by 10 persons = 30 gpm per person
CONCLUSION
gpm divided by personnel = gpm per person
600 gpm divided by 19 persons = 31.5 gpm per person
ANALYSIS
The average fire flow on the incident scene in
the United States ranges between 25 and 50
gpm per person engaged in fire control efforts,
as stated in the charts above.
ANALYSIS
If the fire flow is below 25 gpm/person, you
are probably using 1 1/2” hose.
Consider switching to 1 3/4” hose; or, you
have counted people who are not doing any
of the jobs (reserves).
ANALYSIS
If the fire flow is greater than 50 gpm/person,
you either have too few people doing
ventilation and primary search; or you are
using too few people on each hoseline.
NO master streams allowed during interior
attack.
PROACTIVE USE OF THE DATA
Have each unit that responds report the
number of personnel on board.
Multiply your department’s average flow per
person to get your total capability responding
to this alarm.
PROACTIVE USE OF THE DATA
What total flow for 10 personnel?
What total flow for 15 personnel?
What total flow for 20 personnel?
INTERIOR FIRE ATTACK AND PERSONNEL REQUIRED
Hose size Flow Rates Personnel/Line
1-1/2” 100 gpm 2
1-3/4” 150 gpm 2
2” 150 gpm 2
1-3/4” 240 gpm 3
2” 240 gpm 3
2-1/2” 300 gpm 4+
Large Group Activity 5.2:
Personnel Capability and Distribution Data
Insert 1 story building, 50’ x 90’ approx 25% involved
QUICK ACCESS PERFIRE PLANNING
WHO DOES THE PREFIRE PLANNING
• Proactive fire departments
• Chief officers leading professional departments
• Professional fire officers– paid/volunteer
PURPOSE
• For first-in officers
• A form from which you can read important data
• Does not take the place of a more detailed prefire plan for complex facilities
• Training reference for target hazards
BUILDINGS REQUIRING A PREFIRE PLAN
• Target hazards
• Other important structures/facilities
• Consider smaller structures
WHO USES QUICK ACCESS PREFIRE PLANNING
• First-in company officers/chief officers
• Later arriving chief officers
• Training Officers
Large Group Activity 5.3:
Quick Access Preplanning
Insert slide # 57, module 5
Insert slide # 58, module 5
Insert slide # 59, module 5
Insert slide # 60, module 5
Insert slide # 61, module 5
Insert slide # 62, module 5
Insert slide # 63, module 5
Insert slide # 64, module 5
Insert slide # 65, module 5
Insert slide # 66, module 5
Insert slide # 67, module 5
Insert slide # 68, module 5
Insert slide # 69, module 5
Large Group Activity 5.4:
Building Construction and Fire Behavior Predictions
Single family
Single family fire shot
Apartment shots / multi angle and fire
Large single family use micto stuff
Large single
Large single strip
Wheels in motion fire today
Wheels in motion fire
Wheels after fire
Large mercantile
highrise
Ordinary construction
Insert slide #89, module 5
Insert slide #91, module 5
Insert slide #92, module 5
Insert slide #93, module 5
Insert slide #95, module 5
SUMMARY
Fire flow requirements must be understood
because of the effect on tactical decisions,
resource needs, and safety concerns on the
incident scene.
Knowing your resource capability in terms of
gpm per person on the scene assists in
decision making.
SUMMARY
Prefire planning provides “must know”
information which increases one’s ability to
make correct decisions at an incident.