SRS
SRS
(OP)
Have airbags on the mind. And long before the Takata fiasco there where many people injured or killed by them. I would like to know why certain pressurized gas containers are required to have a pressure relief system or valve, as well as a fairly high strength container, where an airbag inflater can be made from almost a tin can thick steel with no relief system to protect from over pressure. I also curious why such dangerous pressure vessel is allowed to be so many inches from your face, eyes etc. while you are driving a vehicle? Weren't the first airbags deployed by CO2 gas cartridges, located away from the driver?
RE: SRS
RE: SRS
Interestingly, to some degree, that's how some otherwise wimpy tanks provide self-protection in the case where their armor is too thin; they have explosive reactive armor (ERA) which detonate to mess with whatever incoming anti-tank munition making contact with the ERA.
TTFN (ta ta for now)
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RE: SRS
From what I looked at ammonium nitrate is hygroscopic and, with increased moisture, becomes resistant to burning. In the Takata devices the ammonium nitrate was in a small cylinder with periodic vent holes. As the fuel burns the gas was ejected through the incrementally exposed holes. It looked to me like, in the videos showing detonation, that contaminated/compromised fuel wasn't completely burning but instead was ending up plugging the holes - creating a tiny pipe bomb by increased pressure forcing an increase in heat causing bulk detonation.
Research into ammonium nitrate bombs was done by the US military to determine how long an IED based on ammonium nitrate would remain a threat when left exposed to the weather. They concluded that degradation from moisture would render them ineffective at some point.
In any case, the addition of a pressure relief might not be possible, but what is certainly possible is designing a reliable and safe rupture mode that doesn't result in generating shrapnel or a containment/deflection system to guide fragments away from the throats and faces of occupants of cars. I've seen enough explosive-forming of metal and explosive bolts to believe that this is possible. Not doing so is likely to save a dollar or two on the manufacturing cost of the airbag - the likely reason they don't. Note that using ammonium nitrate itself was to save a similar amount of money.
This video - notice the sputtering and then how gas venting slows. https://www.youtube.com/watch?v=eBjxprHh3QI
RE: SRS
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Small and/or light occupants are a real issue.
There are a number of newer implementations that actually alter the inflation based on the sensed weight in the seat (usually just high and low).
I have no idea how effective they are.
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P.E. Metallurgy, consulting work welcomed
RE: SRS
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If the Takata thing bugs you, just get one with airbags from a different supplier. Autoliv is another really common one.
RE: SRS
So a particular car maker recalls for the 2 frontal airbags, and the other 4 are ignored? Does that mean they don't have the dangerous ammonium nitrate that the other 2 have or had?
The blindness issue, there have been many eyes ruined from them, more than deaths.
RE: SRS
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The product, on delivery, was fine - cost effective and reliable. It was only after years of exposure, which might not have been well simulated in accelerated heat w/humidity tests, that the problem was spotted. The squeeze came in thusly - if Takata let on that this was a problem they would not only have to produce all the orders they currently had, get new orders to continue an income, but also spool up manufacturing to replace all inflators they ever made. I think few companies could survive that, plus they would have to somehow also develop an entirely new inflator that could not have any similar defect as both the replacement, the current production, and for future contracts in what would likely be a year before they got cut off by everyone.
Worse, major auto makers knew about these problems, which is what prompted the Takata inquiries, and those companies kept it quiet as well.
I see from https://en.wikipedia.org/wiki/Takata_Corporation that Takata had previously been involved with seatbelt failures and, again, the major makers knew about the problems and kept silent.
In the grand scheme of things, airbags do not guarantee survival; they simply significantly reduce the chances of death or serious injury. And even with the deaths from the shrapnel included, the overall reduction in deaths and other injuries was apparently a very large net positive. I would like that the airbag inflators had been designed to have a safe mode for over-pressure rupture rather than uncontrolled fragmentation.
In looking at some Chinese inflator manufacturer pages, they list a 15 year lifetime for their inflators. It would be nice to know what happens at the end of that time. The price of the inflator is around $20, but I expect that this is not replaceable individually in the airbag system.
RE: SRS
Its just so hard to believe the ignorance of this whole issue. How often are these things removed from various year cars and tested? Some of the recalls are now many years ago. I personally don't care to gamble.
RE: SRS
Vehicle designs are homologated with the airbags specified for them. You can't just swap to a "safer alternative". This is one of the things that trapped Takata and the manufacturers who used them. They knew the design flaw (which accelerated testing could not have found) but they couldn't change the design of the homologated airbags including their inflator without redoing the homologation of all of the affected vehicles, and redoing crash testing of dozens of 10 year old vehicle designs that are no longer in production is not going to happen. The recalls simply replaced like for like. Maybe minor changes to address moisture intrusion could be done but nothing could be changed that affected its performance.
If you don't like this then buy a vehicle with airbags from a different supplier.
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You are more likely to hit the powerball than you are to be killed by airbag shrapnel.
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So NHTSA must care more about the auto manufactures than the folks that get stuck with ill designed junk that may seriously injure or kill them, sort of shows what that organization is all about.
https://www.autoblog.com/2020/01/14/takata-replace...
Supposedly Takata has not used Ammonium Nitrate in the inflators since 2019? And no one cares about what happens when the salt and rice congeal in the last transplanted non azide inflators that are posed in many vehicles on the road and ready to redesign your face.
RE: SRS
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Clearly your real world experience must be wrong, because engineers have not correctly designed anything in any industry since 1949
RE: SRS
A friend's father experienced this, but he was glad since the accident would have been fatal otherwise.
But even the early fairly crude ones were significantly reducing fatalities.
As crumple zone designs improved and they were able to better dissipate the energy of impact and then use more reasonable inflation forces.
I have only been hit by an airbag once. Ironically it wasn't a serious accident. I won't say that it was fun, but it was no big deal.
More of a suprise than anything, it happens incredibly fast. No burns or scrapes, just a few bruises. Didn't even break my glasses.
Cravat, I am large and tall (6'1", 200lb) and I sit way back from the wheel.
Our reliance on a technical solution over behavioral ones in a sign of our times.
Virtually all collisions are the result of driver errors.We are so afraid to impose any restrictions on drivers because the privilege of driving has come to be seen as a right. Granted, we have built a society in US where driving is a necessity of life in most places which compound the problems.
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P.E. Metallurgy, consulting work welcomed
RE: SRS
I will take the no bag option any day over the dangerous inflator.
Airbags do not protect from crushing accidents, they only help keep your head from going through the windshield. Did you ever see the video of the test driver that would daily crash into a wall at 50 to 60 mph, with no seat belt? The solution is simple, airbags where just fine until takata put ammonium nitrate in the inflators. And there are still many unsuspecting car owners and drivers that THINK its all fine and dandy now because of the recalls. NOT TRUE.
RE: SRS
More cars packed onto roads with much poorer drivers.
I'll take the infinitesimally small risk of the airbag over the very real risk of traffic.
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P.E. Metallurgy, consulting work welcomed
RE: SRS
I don't like the impending intrusion of automated systems on the driver's experience, either, but there's a fair argument that what's on the market now (before The Powers That Be impose automated systems that force the vehicle to comply to all posted speed limits, no matter how ridiculously low they may be) strikes the best possible balance between safety and enjoyment. If it all goes self-driving then the car becomes a mere appliance.
It so happens that the car that I drive today (modern Fiat 500) is quite close to the same size as the car that I learned to drive in (1970s-era Honda Civic). I'm pretty sure that if there were to be a hypothetical collision between these two cars, the modern one would go right through the old one, obliterating the old one in the process along with everything inside it, and the smart airbags in the new one might not even fire, due to the collision being not severe enough to warrant setting them off. That experiment has been done, although with vehicles in a bigger size class ... it'll be the same idea, though: https://www.youtube.com/watch?v=vRxLlFm3VUA
RE: SRS
Cheers
Greg Locock
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RE: SRS
I really don't know why I bother responding to your posts anymore. Maybe it's just my sense of the importance of posterity.
Anyway:
https://injuryfacts.nsc.org/motor-vehicle/historic....
https://en.wikipedia.org/wiki/Motor_vehicle_fatali...
https://www.iihs.org/topics/fatality-statistics/de...
As usual, the data indicates that the current rates of traffic fatalities per vehicle and per mile are not only lower than they were in the 70s, 80s, or 90s - they are significantly lower.
Notice that the entire Takata airbag recall incident did not even cause a blip in the aggregate data.
RE: SRS
And curious why would anyone quote Wikipedia?
The real information.
https://www.youtube.com/watch?v=T1-d5emalpI
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Dan - Owner
http://www.Hi-TecDesigns.com
RE: SRS
When I go to Wiki I usually start by looking at the references. If they are a bunch of real sources I'll real it.
No references for youtube is there?
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P.E. Metallurgy, consulting work welcomed
RE: SRS
RE: SRS
I don't know what happened to Sharyl Attkisson. After 21 years she quit national news to join the intentionally politically active Sinclair Broadcast Group.
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When the incident rate is so low that the probability of this happening to any individual person is so small as to not even appear in signal beyond noise, no. It's not really sensational. Notable, perhaps. But sensational? Cause for your apparent hysteria? Certainly not.
Highest occurrence rate for fatalities (allegedly) caused by faulty Takata product appears to be 2016, when there were 7 deaths globally. In 2016 there were roughly 1,350,000 traffic fatalities globally.
This means that in 2016, again the highest rate of incidence, takata airbag failures represented .0005% of traffic fatalities globally.
In that same year, in the US, there were a grand total of 2 fatalities. In 2016, in the US, there were 7,277,000 reported traffic accidents per NHTSA. So your odds of being killed by a Takata airbag failure in 2016 were 1 in 3,638,500.
For comparison:
Odds of being killed in a shark attack (annual average): 1 in 3,748,067
Odds of being killed by a lightning strike: 1 in 79,746
Odds of being killed in a railroad accident: 1 in 156,169
Odds of being killed in an accident involving fireworks: 1 in 340,733
So, yeah. This isn't a major concern about which anyone should be terrified.
RE: SRS
And all those ODDs mean nothing, being killed? I personally don't want to be maimed, especially sight, nor do I want that for my family members either. I don't gamble, if you wish to go ahead.
Logic says get the stinking ammonium nitrate out of the inflators, period.
I would like to know how dangerous the non frontal inflators are? This particular car has 4 more.
RE: SRS
RE: SRS
Yes you do. Every time you get in a car, a train, a plane, or a boat. Any time you leave the house, and any time you DON'T leave the house for that matter.
You could find that out if you were willing to do some reading into those statistics you don't trust or believe.
If you read them you'd discover that, like the frontal inflators which apparently terrify you, they are not really dangerous at all.
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"Schiefgehen wird, was schiefgehen kann" - das Murphygesetz
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One of many photos of people injured.
((((You could find that out if you were willing to do some reading into those statistics you don't trust or believe.))))
(((((If you read them you'd discover that, like the frontal inflators which apparently terrify you, they are not really dangerous at all.))))
Give me some links that show what happens with the other airbags that have an ammonium nitrate failure, I'll be very happy to read them.
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https://www.cnet.com/roadshow/news/takata-airbag-p...
So what happens when the desiccant gets saturated with moisture?
RE: SRS
So........ just fear mongering.
Do you just run around looking at every consumer product you own in terror?
Researching failures that have not happened, to assuage your completely irrational fear, is not my task to complete. If you want to just walk around screaming at the sky for being blue, and wasting time being a drain on this forum, that's on you dude.
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RE: SRS
Dan - Owner
http://www.Hi-TecDesigns.com