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

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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

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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.