12-27-2010, 11:01 AM #1
- Join Date
- Jan 2003
once the bags are deployed does it matter where you cut?
Trying to understand fully the reason for the technique in which we look under interior mouldings for gas cylinders, etc. Would there be any other reason for taking the time to uncover all possible post or headliner locations of hidden cylinders IF all the airbags involved are already deployed during the crash? Once the charged cylinder is deployed, is it rendered harmless? Only other reason I can think of for taking the time, is to find seat belt hard points on the B or C. Removing the trim prior to cutting any post or roof is hounded as a requirement during training, but is that always the case, no matter?
12-27-2010, 02:27 PM #2
- Join Date
- Jul 2007
- Windsor, MA
If all pyrotechnic or compressed gas devices have been deployed or activated, then there is little danger. The problem is that it is impossible to determine if this is the case without dissecting each device. A firefighter is not going to know exactly where every device in every vehicle is and could miss some that have not activated. There are also dual stage air bags which contain 2 separate charges. In a minor impact, only a single charge will go off, and in a more severe impact, both charges may go off. If an air bag has been deployed but the second charge has not gone off, the bag could inflate a second time during extrication, injuring the rescuer or patient.
The point is, you can never be sure what state these devices are in, or even if they have functioned properly, so you should always follow the procedure of removing trim and placing your cuts carefully.
12-27-2010, 03:32 PM #3
12-27-2010, 03:34 PM #4
12-27-2010, 04:21 PM #5
- Join Date
- Jan 2007
A good question
ERG's are a good guide for gaining vehicle knowledge, but are not always based on the reality that we face. Use them as a knowledge base but do not rely on them in the real world.
It is good practice to reveal and check (this only takes seconds) every location we are going to cut spread or ram, not only are we looking for SRS devices we are also looking at where we are going to cut so as to avoid hardened areas that we need to avoid and any other nasties waiting for us.
Its good to get into the habbit of doing this.
In extrication there is a reason for everything we do.
As already stated we may not always know if all the airbags have deployed unless we carry out a thorough scan of the vehicle and in the heat of the moment we could miss some undeployed.
vehicles these days have the capacity to hold as many as 20+ airbags with many being optional extras.
Once side airbags have deployed thats it, it is only the front Driver and passenger airbags that can be duel or multi stage. These are what we need to still worry about even if they have deployed.
Always peel and reveal
The one exception is when a rapid time critical extrication is needed, we do not through caution to the wind we just add different control measures.
I hope that helps
12-27-2010, 09:26 PM #6
12-30-2010, 12:27 AM #7
A couple of added thoughts about stripping or not stripping the trim prior to cutting...
First of all, if you feel this way, that you don't have that moment to strip the trim then I say you're probably too excited; running on adrenaline and not common sense. Slow your breathing, gather your thoughts, and do the job the right way.
The reality is that it doesn't take but a moment to strip away the trim... so make that your 'Plan A'. If something ever went wrong and your cutting caused a catastrophic failure of the fully pressurized stored gas inflator inside the vehicle, you would be found negligent by a jury of your peers. You can count on that. But, what if you still feel for some reason that you don't have that moment to strip the trim? What's your 'Plan B'?
Remember that all vehicles with roof airbags are set up in a mirror image. If you really feel that you don't have the time to strip the trim, then strip the trim on one side before you cut on that side, see what the airbag situation is, and then cut the opposite side in exactly the same places without stripping. The way the airbags are on the driver's side is the same way they are on the passenger's side.
Autoliv, one airbag manufacturer who sells to many major manufacturers, recently answered my question about inflator pressures. I have from them in writing that most of their inflators now have a stored gas pressure of up to 10,000psi. To me, I respect that pressure enough to take that moment to strip the trim. I won't be the one who gets careless and ruptures one of these inflators. Will you?Ron Moore, Forum Moderator
12-30-2010, 10:23 AM #8
Put in another perspective: A TT tire carries about 100Psi give or take. How much damage can THAT do? NOW you have a cylinder,albeit smaller, with WAY more pressure in it. What are you gonna do? Me,I'm going to bust some plastic(STRIP). Enough can go wrong at a scene without ADDING to it. T.C.
12-30-2010, 04:47 PM #9
- Join Date
- May 2008
This video is a good demonstration of how these energized stored gas inflators can become an uncontrolled missle when cut. http://midsouthrescue.tripod.com/sit...s/inflator.mpg
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