Tools & techniques
By Randy Babbitt
Vehicle neutralization:
Is it possible?
T
he simple and eye opening answer to
this question is…NO! In our business,
there is no way to completely neutralize all of
the vehicles that we could possibly run into.
The possibilities are endless! What we can
do is work with a process that will keep us
and the occupants safe 99% of the time. In
no way is 99% safe good enough in our profession, so we must also consider that 1%
that is out there with our name on it. Let’s
discuss a process that involves 3 components
that must be followed to keep a vehicle rescue as safe as possible. Disconnect, Inspect
& RESPECT!
DISCONNECT
Whether you are working on a two-person engine company or five -person truck
company, the team needs to make it their
first priority to cut the vehicles power supply.
Prior to cutting the power, make sure that
there is no need for power to move power
seats, power adjustable pedals or a power
adjustable steering wheel to help free the
patient. Also consider rolling the unbroken
windows down to help manage the amount
of glass in and around the vehicle.
Remember that there are many vehicles
on the road with multiple batteries, which
means that disconnecting the battery under
the hood does not guarantee that all power
sources have been eliminated. In fact, you
may open the hood and not find a battery!
Image #1
Some vehicles have their batteries located
in the trunk (Image #1), under seats,
behind rear seats and even inside the front
wheel wells.
Disconnect (notice I didn’t say cut) the
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negative terminal first, there’s a good reason.
First off, by disconnecting instead of cutting,
you have left yourself the option of reconnecting if you need the power to move the
seat, steering wheel or pedals during your
operation. As for why we disconnect the
negative terminal first…it eliminates arcing
and power surges. Disconnecting the positive
terminal before the negative will most likely
create an arc and an electrical surge through
the vehicle. Both should be avoided!
We’ve all heard of capacitors! Those little
whatchamathingies that store enough power
to fire an airbag even after the battery has
been disconnected. Yes, capacitors do exist
and they are designed to do exactly that.
They store energy to fire the airbags in case
the battery is destroyed or severed during the
impact. Since capacitor life varies from vehicle to vehicle and can range from 1 second to
over 20 minutes, consider all airbags live even
after the battery has been disconnected!
Think about this for minute…airbag initiators require only 7 volts or less to fire.
Most devices that are plugged into cars to
charge off of the vehicles power supply
operate somewhere between 6 and 12 volts.
Once the vehicles power supply stops feeding the device, the device can and most likely will back-feed the vehicle, supplying plenty of voltage to fire any or all of the airbags.
With this being said, unplug anything
plugged into the vehicles cigarette lighter
and/or power ports!
INSPECT
Even if you think you know everything
about a particular vehicle, every car needs to
be inspected to gain the proper intelligence to
proceed with a rescue or extrication.
Your inspection of a vehicle and its hidden
hazards should begin as early as when you are
approaching the accident scene. As you roll
up and look over the scene to assess the overall scene safety, you should also scan the car
or cars involved and ask yourself a few questions about each vehicle…How old is it? Have
I worked on this type of vehicle before? Am I
familiar with this vehicle and any of its systems? Are airbags already deployed? Are
there airbags that have not deployed? The
answers to these questions will help to paint
a picture of what steps you’re going to have
to take in order to make your operation as
safe as possible for you, your fellow firefight-
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ers and the people you’re there to help. This
information is valuable to the entire crew, so
if you have experience or intelligence about a
particular vehicle…TALK IT UP!
The inspection and the questions should
continue as you walk up to the vehicle. Are
there airbags? Which ones are deployed?
Where are my patients? Can you see any
airbag identifiers (Image #2 & 3)?
Image #2
Image #3
Let’s go through a very common situation…A vehicle involved in an accident has its
side impact airbag deployed on the impacted
side only. It is very tempting to go to the
undamaged side, lean through the window
or open the door to make the easy access to
the patient. This is most likely the easiest
access, but it’s not the safest! By doing this
you have put your body in line with a live
airbag that fires down like a guillotine and
has enough power to cripple you for life. The
safe option is to make initial access to the
patient through the impacted side, through
Tools & techniques
the deployed airbag. Just cut the deployed
airbag out of the way if you need to. To
remove the patient, cut the impacted door
out of the way and remove the patient out
through the impacted side and keep the
entire operation away from the live airbag.
It simply comes down to this…consider
all airbags live and RESPECT them and their
power. Use the 5, 10, 20 rule to give yourself
and the patient safe clearance from live
airbags. What’s the 5, 10, 20 rule? Good
question…give a minimum of 5 inches of
clearance from side impact airbags, 10 inches
of clearance from driver side airbags and 20
inches of clearance from passenger side
airbags. These clearances will allow you and
the patient enough separation from the
airbags to make an accidental deployment
cause you to only have to make a trip to
Target to buy new underwear instead of having to make a trip to the trauma center.
If your incident requires extrication using
your hydraulic rescue tools, a more thorough
inspection of the vehicles anatomy has to be
performed prior to forcing or cutting. This
inspection is commonly referred to as “Peel &
Peek”. Call it whatever you want, more
importantly…DO IT! There are way too many
systems in the vehicles on the road today that
can jump out and bite you. You can no
longer blindly cut or force without placing
yourself, your crew and the patient in harm’s
way. Make it simple…don’t cut, spread or
compress interior plastic moldings or upholstery! Get the molding and upholstery out of
the way and inspect what it is hiding!
To properly perform a peel and peek operation, it takes 2 members of the crew. One
firefighter to peel away the interior molding
and upholstery on one side of the car and
another to peek from the opposite side. The
only body parts that should enter the vehicle
during this operation are the hands of the
firefighter that is doing the peeling. The firefighter who is peeking should be looking
through the opposite window, completely
clear of the window opening.
Peel away all of the interior molding and
upholstery that is in the path of your extrication operation. It is not always necessary to
peel both sides of passenger vehicles and
pickups, the 2 sides are usually identical. But
when in doubt, take the time to expose wherever you are working. Vehicles like vans and
some suv’s that have different window and
door configurations from one side of the vehi-
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cle to the other, definitely require a complete
inspection of both sides.
So…what are you looking for? Since the
majority of our extrication procedures involve
cutting posts and roof rails to remove or fold
back roofs, the most hazardous items that we
are going to run into are compressed gas
cylinders used for inflating side impact protection airbags (Image #4). There is no real
Image #4
standard on where the cylinders are located;
in fact they can be located in 12 different
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Tools & techniques
Image #5
locations on both sides of the vehicle
(Image#5). The cylinders vary slightly from
manufacturer to manufacturer, but they all
have a similar look and should be easily identified once exposed.
These cylinders store high pressure compressed gas (usually argon) that is activated
to rapidly deploy the
airbag, the cylinders have
to be extremely high pressure. How does 4,000 to
9,300 psi sound? You read
that right…up to 9,300 psi!
I think it goes without saying that cutting through a
cylinder pressurized to
upwards of 9,300 psi could
create a problem and
deserves some RESPECT.
You must cut around these cylinders!
You should also avoid the wires that are
could pass through the vehicle to the wires
and activate the airbag…RESPECT the wires.
If you need to cut the initiator wires, do so
with wire cutters and don’t allow the wire
cutters or the ends of the wires to touch any
metal on the car.
The discharge tube that supplies the
airbag from the high pressure cylinder and
the airbag itself can be cut. Just keep in mind
that if for some reason the cylinder is activated without the airbag attached to absorb the
expelled gas, there is now an open butt for all
of that energy to release through. You
should RESPECT this and keep your vital parts
away from the opening.
Another system that you can find in B-pillars, C-pillars and sometimes even in roof
rails, are seatbelt pre-tensioners (Image #10).
Image #8
Image #6
attached to the cylinders. Airbag initiator
wires are usually (not always) identified with a
yellow sheath (Image #9). If you were to cut
by a pyrotechnic charge causing the gas to
expel and inflate the airbag (Image #6). Since
space is limited in the roof rails and pillars
Image #10
Image #9
Image #7
where the manufacturers mount these cylinders (image #7 & 8), the cylinders are small.
In order to get the volume and force required
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through these wires with your hydraulic cutters, you would push the wires into the metal
structure of the car. Since there is a slight
possibility that the car is energized from the
accident, there could be enough voltage that
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These systems commonly use a nitrocellulose
pyrotechnic charge to provide the energy to
retract the seatbelt during an impact. The
pyrotechnics charges are small and pose less
of a hazard than the airbag cylinders, but still
deserve RESPECT and should be avoided.
Seatbelt pre-tensioners can also be found
to the inside of the passenger seats as part of
the seatbelt latch receiver (Image #11).
Rarely is there a need to use hydraulic tools in
this area, but in those rare instances that you
do, these deserve your RESPECT and you
should work around them.
One more thing about seatbelts…if the
patient is not supported or suspended from
their seatbelt…cut it. This will eliminate any
Tools & techniques
tured since 1984. It gives you battery location, capacitor drain down times, air bag locations, seatbelt pre-tensioner locations, impact
sensor locations, airbag control module location and more. I would highly recommend
that every department include this guide in
their library.
Be safe & happy cutting!
Randy Babbitt is an auto extrication special-
ist / instructor who teaches auto extrication
techniques and vehicle anatomy throughout
California. He is a registered auto extrication instructor with state fire training and 22
year veteran of the fire service. Randy is a
16 year member of the Huntington Beach
Fire Department where he has served the
past 11 years as a Truck Engineer. Randy can
be reach at [email protected] for
questions and comments.
Image #11
injury to the patient if the pre-tensioner was
to activate during the extrication.
RESPECT
The obvious theme that should run
through your entire vehicle rescue/extrication
operation is RESPECT! RESPECT the potential
that all supplemental restraint system components possess! If it looks like it can jump out
and bite you, it probably can…so RESPECT it
and work around it!
In Conclusion…
As vehicle safety system technology progresses to provide more safety for vehicle
occupants, additional hazards to rescue
workers are created. As rescue workers, we
can no longer blindly cut and force our way
into vehicles. We need to see what we’re
cutting or forcing so we can avoid becoming
a statistic. It doesn’t matter where on the
vehicle you are working, if there’s plastic
molding or upholstery between your cutter
blades or in the path of your spreader tips,
you’ve missed a step! Stop…remove the
molding and upholstery, expose what’s hidden behind it and you might find something
that you don’t want to tangle with!
Recommendation…
Holmatro publishes an incredible reference guide called; “The Rescuers Guide to
Vehicle Safety Systems”. The guide comes in
print and CD form and it lists every safety system component on every vehicle manufacJULY/AUGUST 2010
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