Wind Driven Structure Fires PowerPoint

Wind Driven Structure Fires

Wind is

something we

have been dealing

with forever. Why

the new

phenomenon?

The fact of the matter is, wind

isn't a new phenomenon. It’s

our lack of situational

awareness during structure

fires that has led to a

staggering amount of Line of

Duty Deaths (LODD) and near

misses during wind driven

structure fires.

http://commandsafety.com/2011/04/prince-william-county-va-fire-rescue-kyle-wilson-lodd-2007-is-this-on-your-radar-screen/

Sustained 15mph winds

with gust up to 35mph.

http://www.cdc.gov/niosh/fire/pdfs/face9901.pdf

Wind: Sustained 14mph winds

from south/southwest with gusts

up to 31mph

http://www.cdc.gov/niosh/fire/reports/face200502.html

Wind: Sustained winds from

east/south-east at 17mph with

gusts up to 26mph

http://www.cdc.gov/niosh/fire/reports/face200911.html

In Prince George’s County (Maryland), firefighters

arrive on scene to a structure fire with winds

impacting the rear of the structure. Shortly after

forcing the front door open, they saw a dramatic

change in fire behavior. As they made entry, they

quickly experienced high velocity and high

temperature gases, injuring seven firefighters, two

critically. http://commandsafety.com/2012/02/residential-fire-injures-seven-firefighters-wind-driven-conditions-suspected/

We commonly associate

“wind driven” with brush fires.

Recent research and incidents

have made it clear that our

situational awareness, in

regards to weather, is just as

important during structure

fires as it is with brush fires.

Would you stand in the middle of

this fuel bed with wind pushing

fire towards you?

NO

Then why would we stand in the

middle of this fuel bed, which burns

hotter and faster, with wind pushing

fire towards us?

Lesson Objectives

• Identify some indicators wind is

affecting the fire

• Discuss how wind affects the Flow

Path

• Discuss the Blowtorch Effect

• Discuss the Blowtorch Triangle

• Review Tactical Guidelines to consider

• Review Safety Guidelines to consider

What are some

indicators wind is

affecting the fire?

1. Weather Conditions

Wind as little as 10 mph

can cause rapid fire

progression in a

structure. Be aware of

your environment while

en route and once on

scene. The Dangers of Wind-Driven Residential Fires by William R. Mora, Sept 2010

General Wind Effect

Wind-Driven Structure Fires: Adjusting Tactics and Strategies by Kriss Garcia, 5/1/2011

2. Distinguishable Fire Behavior

During Size Up

Pulsing flames coming from

upwind window.

Pressurized smoke coming from closed doors in the

potential flow path.

Flames not exiting an upwind window

Pulsing Flames from Exterior

If the window is being

impacted by 20mph

winds, why do the flames

“pulse” out of the

window?

The fire is under such

high pressure it is

basically “burping

itself.” It cannot release

all of its pressure

through the exit vent.

3. Unplanned Ventilation

• Was there a door left open on the upwind

side of the structure?

• Is there a broken/failed window on the

upwind side of the structure?

1. Be aware of current,

predicted and local weather

patterns for the day in your

jurisdiction and those

surrounding you.

2. Note the wind conditions

when you pull out of the barn.

4. Be aware of potential

rapid fire progression

3. Observe fire conditions on the

upwind side of the building before

entering (pulsing flames?)

Most Importantly: Be Heads Up

How does wind

affect the flow

path?

We know from last

month, a Flow Path is

the area between

where the fire is and

where the fire wants

to go.

Flow Path with Wind

Vs.

Flow Path with no Wind

Establishing a flow path in a

structure with no wind.

1. Window creates a

bidirectional flow with

fresh air coming in

through the bottom and

exhaust coming out the

top.

2. Once the ceiling vent

is opened, it pulls the

heated gas, smoke and

fire to it creating a flow

path. Notice the

bidirectional flow at the

window remains.

1

2

Bidirectional Flow

Establishing a flow path in a

structure with wind.

1. The wind overrides

the pressure of the

outlet in the window

creating a unidirectional

flow path INTO the

structure.

1

2

Unidirectional Flow

2. The ceiling vent

provides the only exit for

the exhaust. The wind

forces all the hot gases,

smoke and fire rapidly

through the structure to

the only outlet. Note the

unidirectional flow.

Effects of Wind on a Flow Path:

Notice the direction of the flow path 10 seconds before

wind is introduced (left) and 10 seconds after wind is

introduced (right).

Win

d

Win

d

When wind is introduced to

a completed flow path it

can create a unidirectional

flow from floor to ceiling.

This is what witnesses

describe as the Blowtorch

Effect.

Blowtorch Effect

As a crew, watch the Blowtorch Experiment

videos linked in the Wind Driven Structure

Fire Lesson File.

Note the rapid fire progression and

untenable conditions.

Blowtorch Situational

Awareness

How can we reduce the possibility of experiencing the

Blowtorch Effect?

Door Control.

Remember to

control exterior

and interior

openings we

pass through or

encounter. Heat

How can we take away the Outlet?

Po

ten

tial F

low

Path

Prior to fire attack

entry we notice:

1. A mild breeze

2. A well established

fire in the living

room

3. Failed window in

the living room

Failed Window

Wind

Front Door

Closed

Heat and smoke are

traveling through the

structure as typically

expected.

Failed Window The pressure from

the wind creates

the Blowtorch

Effect charging

down the hall right

to the fire attack

crew.

Front Door

Open Crews make entry

through the front door

completing the flow

path.

Flo

w P

ath

/ B

low

torc

h

When the fire attack crew

utilizes door control it

reduces the potential

flow path thus reducing

the potential for the

Blowtorch Effect.

Failed Window Remember, any

additional unplanned

or uncoordinated

ventilation will create

a flow path to the vent

opening.

Po

ten

tial F

low

Path

Is there

another

tactic we

can deploy

in order to

prevent the

blowtorch

effect prior

to entry?

Failed Window

Exterior

Water

Application

or

“transitional

attack.”

How can we take away Heat?

Exterior water

application, prior

to entry, will help

extinguish the

gases and reset

the fire to a

contents fire

allowing for more

tenable

conditions for

interior crews.

NIST Exterior Water Application

Experiment

Remember a straight stream directed at the ceiling

improved conditions throughout the structure.

IT DID NOT PUSH FIRE

Heat

Can we minimize the

wind’s impact on the

fire?

How can we take away the Inlet?

Wind Control Device (WCD)

FDNY and NIST experimented covering

window openings with Wind Control Devices

and salvage covers.

The WCD’s minimized the winds impact on fire spread throughout the structure.

High Rise

Experiment

Heat

UL and NIST

continue to

research tactics

that can be

implemented to

prevent the

Blowtorch Effect

when there is

limited access to

the upwind side.

Tactical Considerations

for Wind Driven

Structure Fires

Communicate

Coordinate

Control

Tactical Considerations for Wind Driven Structure Fire

Communicate • Report wind conditions upon arrival

during size up

• Advise interior attack crew if any

windows or doors are open to exterior of

building after 360

• When choosing a ventilation location,

communicate with interior crews to

ensure an undesirable flow path is not

created


Coordinate

• Consider attacking the fire from

involved to uninvolved

• Consider exterior water application

before interior attack

• Coordinate water application with

ventilation


Uninvolved to involved may not

always be the best attack

• In a wind driven event, fighting the fire

from the uninvolved to the involved can

put you straight in the flow path of the

fire. NOT A GOOD PLACE TO BE!


Control

• Limit vent points: Perform door

control and coordinated ventilation;

consider wind control measures.


Safety Guidelines for

Wind Driven Structure

Fires

How about applying

LCES on a

structure fire just

as we do on a

brush fire?

Implementing LCES in a

Structure Fire Setting

• Lookouts

– Incident Command Staff: must be aware of

changing conditions.

– Door control firefighter: monitors smoke

conditions coming from the building and the

location of the firefighters inside.

– RIC team: perform 360 size up, constantly

watch for changing conditions

– Remember everyone can be considered a

lookout. IF YOU SEE IT SAY IT.



• Communication

–Report wind conditions upon arrival

–Report status of doors and windows

(open/closed)

–Report changing conditions

• Escape Routes

–Operating from the upwind side of the

structure can allow for easier escape

routes and safety zones

– It may be impossible to ensure escape

routes and safety zones on the downwind

side of the structure due to the potential of

extreme and unpredictable fire behavior

Implementing LCES in a Wind

Driven Structure Fire Setting

• Safety Zones

–Entering a bedroom and closing

the door behind you can create a

temporary refuge area (TRA).

This can significantly increase

survival time until rescue or escape



Director of Training

Battalion Chief Derek Alkonis

LACoFD Training Services Section

(323) 881-2436

Wind Driven Structure Fires PowerPoint

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