Wind Driven Structure Fires PowerPoint
Transcript of 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?
Heat
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
Tactical Considerations for Wind Driven Structure Fire
Coordinate
• Consider attacking the fire from
involved to uninvolved
• Consider exterior water application
before interior attack
• Coordinate water application with
ventilation
Tactical Considerations for Wind Driven Structure Fire
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!
Tactical Considerations for Wind Driven Structure Fire
Control
• Limit vent points: Perform door
control and coordinated ventilation;
consider wind control measures.
Tactical Considerations for Wind Driven Structure Fire
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.
Implementing LCES in a
Structure Fire Setting
• 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
Implementing LCES in a
Structure Fire Setting
Director of Training
Battalion Chief Derek Alkonis
LACoFD Training Services Section
(323) 881-2436