Fire vs. Water Flow

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Fire vs. Water Flow
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Whats the best size for an attack line?
What factors are the highest priority on your
department?
11/2 ?
1 ?

• Maximum flow
• Maximum mobility
• Speed-How fast and how much
• Ease of deployment and pickup
• Personnel available
• Water supply available

13/4 ?
2 ?
21/2 ?
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Pump Pressure for 125 GPM
1
452 psi
150 feet
156 psi
1½
150 feet
1¾
136 psi
150 feet
105 psi
2½
150 feet
(100 psi nozzle pressure)
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Larger Attack Hose Lines Equal...

• Higher initial attack flow capability
• Less friction loss
• Longer hose lay capability
• Using more of pumps capacity

Higher Flows Equal...

• Quicker fire knockdown
• Personnel spend less time in combat
• More lives saved
• More property saved

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Fire Ground Hydraulics?
175?
Pump Pressure?
120?
P.S.I.?
Loss per 100 ft.?
Hose Diameter?
Elevation Loss?
Device Loss?
GPM?
200?
150?
Nozzle pressure?
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The Preconnect...

• The Preconnect is always the first line off
• The first two lines down fight most of our fires
• Can they handle most anything our department is
  normally going to fight?

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The Pre-Con 150 Play

• 150 of 1¾ _at_ 150 psi 150 GPM
• Works most of the time
• Its the easiest and most often practiced
• Simplifies pump operation (only one pressure
  works)
• But... is it the right choice, THIS time??

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How will we handle 90 of our fires?
I got it, Chief!!

• 90 of our fires result in 10 of our losses
• however,
• 10 of our fires result in 90 of our losses!

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Will we count it as a great save...... or a
futile training exercise?
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ISO Ratings

• Insurance Service Offices
• Grading of fire departments capabilitiesand
  equipment
• For determining fire insurance premiums
• Not an application rate formula

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NFPA Water Supply Formulas

• For pre-planning water supply
• To determine total quantity of water needed
• For a single structure
• Or a group of buildings
• Type of construction
• Occupancy rating
• Exposures
• Refer to NFPA 1231 Suburban Rural Water
  Supplies

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Iowa State University Formula
L Length W Width H Height
GPM L x W x H 100

• Fire knockdown in 60 seconds or less
• Normally for enclosed areas
• Can be used in pre-planning water requirements
  for a building or room

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National Fire Academy Formula for Quick
Size-up...

• GPM L x W
• 3
• Fire knockdown in 30 seconds or less
• Multiply GPM by number of floors involved
• Can be adjusted for actual of involvement
• Choose appropriate size number of attack lines
  based on GPM required other situational factors

L Length W Width
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Formulas Fire Loading of Structures...

• National Fire Academy Formula
• Current information
• Fire load contains more synthetics
• Synthetics produce more BTUs per pound
  increase smoke noxious gas output
• Ventilation and interior attack tactics utilized
• Increased water flow required due to increased
  heat output

• Iowa State University Formula
• Developed in the 1950s
• Fire load mostly organic materials
• Ventilation tactics utilized less often
• Attack often from outside due to lack of
  breathing apparatus, protective clothing, other
  safety equipment