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slantvaliant
slantvaliant Reader
8/4/09 8:13 a.m.

Commercial from the 70's:

British sports car speeding toward a brick wall in an apparent crash test.

"We at British Leyland prefer to miss the wall."

Car neatly zigs around the wall.

wlkelley3
wlkelley3 HalfDork
8/4/09 11:41 a.m.

So what we're saying is that everyone needs a full roll cage, a 6-point harness w/hans and helmet to be safe. Well the helmet part might actually result in less cell phone talking and that could defintely help. But might mess up the 'do and we can't have that can we?

agree to disagree!

Rufledt
Rufledt New Reader
8/4/09 12:02 p.m.
wlkelley3 wrote: Well the helmet part might actually result in less cell phone talking and that could defintely help. But might mess up the 'do and we can't have that can we? agree to disagree!

anything to discourage those stupid inattentive people one the phone while driving!!! i honestly believe some people can handle talking on the phone while driving, and some people just don't possess the brain power to handle talking and driving! but then they'd just invent hands free helmet phones... i wouldn't mind racing seats and hanesses in street cars personally, but i tihnk it would be difficult getting most americans into a racing bucket...

Shaun
Shaun New Reader
8/4/09 12:17 p.m.

" i honestly believe some people can handle talking on the phone while driving, and some people just don't possess the brain power to handle talking and driving! "

You are an optimist! I believe many people do not posses the brain power to handle either talking on their cell phone or driving.

81gtv6
81gtv6 Reader
8/4/09 3:03 p.m.

I think we need a law that says if you are in an accident and are not using your seatbelts the insurance does not have to pay. I think I remember my parents talking about that being a law in Germany when we lived there in the early 80's.

It is not my driving that makes me use my seatbelt every time I get in a vehical, it is everyone else. Our "Drivers Training" is a joke, I think we could learn a thing or two here from the Europeans. When I lived in Germany there were dependants that turned 16 and could not drive, you had to be 18 along with taking classes that really showed you how to drive.

In the spirit of stimulus and safety I think the government should mandate and pay for everyone that wants to get a DL to go to one of those teenage survival driving schools, lord knows all of my kids are going as soon as they can. Why do we find it so hard fix the problem and not the simptome.

billy3esq
billy3esq Dork
8/4/09 4:56 p.m.
Shaun wrote: I believe many people do not posses the brain power to handle either talking on their cell phone or driving.

You, sir, are my new hero, merely for stating the obvious that few would have the audacity to suggest.

Jensenman
Jensenman SuperDork
8/4/09 6:08 p.m.
thedude wrote: Another point Roll cages don't crumple. They are meant to remain in shape to protect the driver and keep adequate space between him and the outside world. Because the car with a roll cage doesn't crumple, there are greater forces exerted on the driver's body (the car itself does not give and therefor the deceleration rate experienced by the driver is greater) to slow him in the event of a crash. To make up for this, the force of the impact must be spread over more of the body which leads to harnesses. Believe it or not, millions of people sacrifice their safety everyday so that they don't have to strap on a 5 point harness, buckle their helmet and hans device and arm the fire suppression system every time they drive. Cars are full of compromises one of them being airbags. They slow you down slower and you don't have to think about them.

Check the link I posted to NHTSA's stats on small car deaths. The majority come from cockpit intrusion and deformation. Those same cars are equpped with airbags. What good is an airbag if the car folds up around you like a cheap lawn chair?

Volvo's 'safety cage' involved a reinforced passenger compartment and crumple zones built into the engine compartment and trunk. The car is designed so that if the driver hits something at the front, the engine is shoved down and out of the car, rather than it screwing with the absorption of crash energy.

Jensenman
Jensenman SuperDork
8/4/09 6:20 p.m.
billy3esq wrote:
Jensenman wrote: billy3, as far as the actuarial tables go they gather only information from vehicles equipped with the current system of Mickey Mouse intrusion protection and airbags. Since they have no pool of information on other designs to draw from, of course airbags look great. How could they not?
Bzzzt. Thanks for playing. That's not how actuarial science (statistics on steroids) works. Insurers have stacks and stacks of data going back a long time with lots and lots of variables from which to draw inferences. Admittedly, the best data is probably from the transition years when model year to model year changes could have otherwise similar vehicles with only changes in the airbags, but the data is still statistically valid. Moreover, there are lots of mathematical techniques that would make your eyeballs explode for isolating the effect of particular variables on a data set. (It makes my eyeballs explode, and I minored in mathematics.) Insurers' claims experience clearly suggests that vehicles with airbags have improved claims experience versus similar vehicles that don't. Otherwise they wouldn't offer a discount. If airbags didn't improve claims experience, what possible motive could they have for offering a discount? (Hint: if you think there is one, see comment above about appropriate shielding for headgear.) Since we all know that airbags result in more expensive repairs to the vehicle, the improved claims experience must come from some combination of: (1) fewer injuries, (2) less severe injuries, and (3) fewer fatalities. Of course claims experience is to some degree aggregated, meaning that in any given event airbags may contribute to more injuries, more severe injuries, and/or fatalities. However, since I don't get to pick the exact dynamics of my crash, I'll stick to playing the odds. Could a hypothetical engineer with an unlimited budget and no market constraints come up with something better? Maybe. That doesn't mean that airbags aren't better than the absence of airbags. Then again, what do I know. I like ABS and stability control (in street cars), too.

And you reinforce my point. So the insurers infer from current actuarial data that airbags do help. Okay, i conced the point. There are no actuarial studies or data (at least that I am aware of) comparing cars with better reinforced bodies to those without. So there's a huge hole in the actuarial data. Bzzt.

BTW: ABS is a good thing in street cars, it really helps when some assclown driving a beige Accord with Kentucky tags cuts across four lanes of traffic at highway speeds and then jumps on the brakes so he doesn't miss his exit, not paying any attention to the guy just behind him towing a race car on a trailer. (Mr. Kentucky Honda, if you are reading this: the only reason you and your kids are alive now is that ABS system. 8000 pounds of tow vehicle and trailer would have rolled over that non-roof-reinforced Honda like it was a rotten grapefruit.)

Stability control is for those who cannot drive, generally the same people who cannot drive and talk on a phone at the same time. We won't discuss texting or twittering while driving.

Keith
Keith GRM+ Memberand SuperDork
8/4/09 6:25 p.m.

If stability control keeps someone who can't drive out of an accident, then it's beneficial. Cellphone jammers in cars would probably work pretty well for accident prevention as well!

By the way, one of the coolest things about working in a shop that does salvage work is crawling over and through the wrecks. The amount of detail that goes into the controlled compaction of cars is fascinating.

This poor little guy was shortened by a couple of feet. The engine had moved down, the powerplant frame was buckled, the differential detached from its mountings to move back, the steering wheel broke off the hub - and it was all intentional. Look at the creases in the unibody in front of the rear wheel - we see that a fair bit. The car worked as intended. The most amazing thing is that both doors still opened and the blue suede seats appeared to be without stains.

S2
S2 New Reader
8/4/09 6:34 p.m.

Keith's picture points out what a properly engineered "system" should do- the passenger compartment remains intact and with minimal deformation while the rest of the car is designed to deform greatly (sacrificed) to adsorb the excess energy and prevent its transfer to the passenger compartment (and the flesh puppets inside). I saw a 928 that bit the wall on the autobahn- multiple rollover, front end gone, but the passenger cage was intact.

Makes me think that an integrated cage like J-man is advocating (and is in my subaru too) + airbags is a better way to go.

Jensenman
Jensenman SuperDork
8/4/09 6:38 p.m.

Wow. Wonder what the speed was in that crash?

There's a perfect example of a passenger compartment which didn't deform in a major way during a crash (although it did deform some; look how loose the top material is. The windshieldframe moved back some). Which again reinforces my point about strengthening the passenger compartment properly.

Yeah, some of the crash detail stuff is interesting. Look at the underside of a hood, you'll see stamped creases in the edge reinforcement so it will bend there. Then you will also see a hook on the rear of a hood hinge and a matching eyelet somewhere on the body or hinge, that's so the hood won't rise up and come backwards through the windshield.

I've seen more than one Miata hit from the front and the footwells will buckle where the front subframe's rear bolts go.

S2
S2 New Reader
8/4/09 6:39 p.m.

Oh, I know there are some reports of airbags discharging "spontaneously" on the net that I won't refute, but modern explosives are quite stable and don't typically detonate unless provoked. I'm willing to bet there is still plenty of '50's and '60's era C4, TNT, and Dynamite in the Army stores despite the recent inventory reduction opportunities- I know I've blown plenty while wearing a green suit, and it worked as advertised.

nderwater
nderwater Reader
8/4/09 9:43 p.m.

Airbags helped save my mother's life when an idiot in a (empty) school van drove across a rural highway right in front of her. She t-boned it at nearly 70 mph and walked away with some soreness and minor burns from the bag.

I'm all for active safety restraints which kick in when needed to save a life.

MrJoshua
MrJoshua SuperDork
8/4/09 11:44 p.m.

But if mom were the person who broke her forearm across her face when she got in an "Accident" while turning would you feel the same?

Wally
Wally GRM+ Memberand SuperDork
8/5/09 1:29 a.m.

Something else to look at besides the airbags are folding rear seats. The white crate in the rear window was in the trunk filled with emergency stuff, jumper cables lug wrench ect, my little hydrulic jack landed in the passenger side airbag, and the milk jug of oil I meant to drop off at Autozone that morning hit the back of my seat. It all knocked down back seat like it wasn't there.

Jensenman
Jensenman SuperDork
8/5/09 7:11 a.m.

nderwater, not a flame, just want to make sure we are all on the same page: airbags are passive safety features, ie there is no action required on the operators' part for the item to operate. This includes ABS, body reinforcements, etc and most safety features fall in this category.

Active safety features would include seat belts since the operator has to buckle them. The seat belt is about the only active safety feature I can think of.

There have been situations where it wasn't so much spontaneous as unexpected airbag deployment. Mazda had a recall on certain models (including some Miatas) where it was possible that, if you hit a big enough pothole, the bags would deploy. Part of that recall was cutting off the factory shipping tiedown hooks, seems they would snag on big enough speed bumps. The momentary deceleration could fire the bags.

Since I have been in the business, I have never seen an airbag deploy all on its own.

Airbags are useful in some situations but it's actually a rather narrow set of circumstances. [broken record] The NHTSA's own numbers point out that in smaller cars with airbags many deaths and serious injuries still occur due to passenger compartment deformation. The same holds true of larger vehicles such as SUVs in rollovers. [/broken record]

Airbags can and do injure people. Nissan was investigated a while back for overpowered airbags which uncoiled in such a way that it could hit the passengers' face almost like a fist. That and a spate of child deaths due to young children being in the wrong place (the right front seat) led to the development of the 'smart' airbag. Here's what happened, much compressed: the original NHTSA standard was to cushion a 175 pound person in, IIRC, a 40 MPH crash and I believe the occupant was not belted in. Without going into a lot of math, to get the decel rate right the bag had to be very powerful. This meant the things most assuredly could injure or kill someone who was too close to the bag, like little old ladies, very short people, young children, etc. Sorta backwards from what was intended. The smart bag module takes into account seat position and weight on the seat and adjusts the potential output accordingly. The downside: the lower threshold weight is 40 pounds and lots of people throw all kinds of stuff on the right front seat (laptops, groceries, you name it. I once had a lady get PISSED at me because I told her the duck decoy she stored under the passenger seat was what turned the airbag light on). The module doesn't know what to make of this so it turns the passenger bag off completely and turns on the airbag light to tell the driver to have it checked. Unfortunately a lot of people just ignore the light.

Another thing about airbags: as someone noted in an earlier post, they are part of a restraint system which includes the seat belts. The belts have to be tight to work, tighter than most people will wear them, so seat belts have 'pretensioners' which are fired by the airbag module. Basically, the buckle assembly (and sometimes the reel) has a pyrotechnic in it which fires off and yanks the belt tight for a short time. Problem is, like an airbag, it's only good for one lick. In a multiple strike situation after #1 the occupant is on his/her own.

Wally's experience with loose stuff in the back of the car is not unusual. In a crash, all kinds of stuff becomes missiles inside the car. Just imagine in a 60 MPH crash on the way home from the grocery store getting hit in the back of the head by a # 303 veggie can. But in a lot of cases, people pay no attention to that sort of danger.

In many newer cars with trunks, the bulkhead behind the rear seat is a 20 gauge steel sheet with a few holes poked through it for wires etc. Stuff in the trunk has little or no chance of getting through that. Used to be (and Wally's Escort would be one of these) this bulkhead was an X or V shaped reinforcement with large openings. So yes stuff could very well sail through the rear seat backrest easily. Cars with folding rear seats (like our '94 Accord) have a large opening so that long objects (such as skis) can be carried and generally have a steel pan for the backrest which locks into latches very similar to door latches. In that way they are very similar to the solid bulkhead when the seats are upright.

thedude
thedude New Reader
8/5/09 11:03 a.m.
MrJoshua wrote: But if mom were the person who broke her forearm across her face when she got in an "Accident" while turning would you feel the same?

I think most people would take their life and a broken arm over death and an unbroken arm.

Airbags aren't a perfect solution but I believe they are better than not having them. I don't understand the argument that because cars should have roll cages built in, current cars should not have airbags.

S2Fella
S2Fella New Reader
8/5/09 11:23 a.m.

No seatbelts, no airbags and a big spike coming from the center of the steering wheel aimed right at your chest.

Then everybody would drive a whole lot safer.

Seriously, they have studies that show that pedestrian deaths increase when mandatory seatbelt laws are implemented - presumably because the additional sense of safety the driver gets means they drive less cautiously. I imagine the same is true when your average driver is surrounded by 16 airbags, ESC etc etc. - sure it's OK to be on the cell phone and drinking a coffee - I have all this safety crap so I don't need to pay attention.

moerdogg
moerdogg None
8/5/09 12:26 p.m.
Jensenman wrote: Active safety features would include seat belts since the operator has to buckle them. The seat belt is about the only active safety feature I can think of.

Um, brakes?

And as far as the discussion of stability control goes, I remember reading somewhere - and I cannot for the life of me find the article again - that it was the largest improvement in auto safety since the invention of the seat belt, more than air bags or ABS. For all that having the computer nanny is annoying, the system can react to road conditions far faster than any human. Doesn't help if you are talking on the cell phone to your husband while backing up and drive into your landord's crane, though. Not saying my wife did that, it's purely hypothetical.

aircooled
aircooled SuperDork
8/5/09 12:28 p.m.
slantvaliant wrote: Commercial from the 70's: British sports car speeding toward a brick wall in an apparent crash test. "We at British Leyland prefer to miss the wall." Car neatly zigs around the wall, with insane amounts of tire screeching, body roll and really scary suspension movements.

Added some detail for your there

billy3esq
billy3esq Dork
8/5/09 3:09 p.m.
Jensenman wrote: And you reinforce my point. So the insurers infer from current actuarial data that airbags do help. Okay, i conced the point. There are no actuarial studies or data (at least that I am aware of) comparing cars with better reinforced bodies to those without. So there's a huge hole in the actuarial data. Bzzt.

If I'm reinforcing your point, then at least one of us doesn't understand your point.

I understand your point to be that more rigid passenger compartments would be of greater safety benefit than airbags. I further understand that you base this conclusion on some combination of your experience with a Sawzall and the absence of actuarial evidence to the contrary. While I will concede your substantial Sawzall prowess, "absence of evidence is not evidence of absence."

The rigidity of passenger compartments is a certainly a factor in the actuarial analysis of vehicles, but will be built into the base rate for a given vehicle. From my understanding of vehicle crash dynamics, there's no way to measure structural rigidity in a way that correlates with injury experience. OTOH, it is possible to correlate the absence or presence of airbags with injury experience.

Thus, the actuarial data support the notion that airbags make vehicles safer and that more rigid passenger compartments (at least to a point) make vehicles safer. What the actuarial data do not support (from what I have seen) is your conclusion that more rigid bodies make more difference than airbags. (Admittedly, I'm not up on the latest actuarial studies or the SAE literature on point.) Even if the data did support that, in the real world the monetary measure of risk (what I chimed-in about) would be built into vehicle-to-vehicle base rate comparisons and not per-vehicle discounts.

I do agree with you that, all things being equal, a more rigid passenger compartment (a/k/a "safety cage") coupled with controlled deformation extremities (a/k/a "crumple zones") will provide an enhanced degree of safety. Like airbags, virtually all cars manufactured in the last 15-20 years have had some variation on this theme. Obviously, some manufacturers (e.g., Volvo) are better at it than others (e.g., Kia).

You keep returning to airbags not helping in small car collisions that result in significant deformation of the passenger compartment. However, the real issues are mass and kinetic energy. The energy of the collision has to go somewhere. It can either go into: (1) accelerating (decelerating) the vehicles involved or (2) deforming the vehicles involved. Too much of either is bad.

A too rigid vehicle means that you die of injuries caused by rapid deceleration instead of being crushed and vice-versa. A more massive vehicle allows more energy to be dissipated in the acceleration (deceleration), but comes with a whole bunch of problems that we all know about.

Vehicle engineers have a whole host of parameters (including cost) they have to consider in optimizing a vehicle design. There is no "right" answer to any of these problems. By definition, an multi-scenario optimization problem means that performance will be sub-optimal in some, if not all, scenarios.

The fact that you would pick a different point on the optimization curve than the engineers have selected merely means some combination of: (1) you weight different parameters differently, (2) you are considering a different set of parameters, (3) you are smarter than they are, or vice-versa.

I spent enough time as an engineer to know that most people who second guessed my design decisions were looking at less data and/or were less proficient in engineering analysis than I was. Because of this, in the absence of substantial evidence to the contrary, I am willing to defer to the judgment of people who have more data than I do and do it for a living.

Jensenman
Jensenman SuperDork
8/5/09 4:12 p.m.
thedude wrote:
MrJoshua wrote: But if mom were the person who broke her forearm across her face when she got in an "Accident" while turning would you feel the same?
I think most people would take their life and a broken arm over death and an unbroken arm. Airbags aren't a perfect solution but I believe they are better than not having them. I don't understand the argument that because cars should have roll cages built in, current cars should not have airbags.

At no point did I say there should be no airbags. I did say (more than once) that they are a partial solution. IMHO a lot more effort and money should have gone into strengthening the passenger compartment rather than basically ignoring that facet, stuffing airbags into every available crevice and calling that a fix for everything, i.e. the appearance of safety rather than the reality.

poopshovel
poopshovel SuperDork
8/5/09 4:13 p.m.
Wally wrote: Something else to look at besides the airbags are folding rear seats. The white crate in the rear window was in the trunk filled with emergency stuff, jumper cables lug wrench ect, my little hydrulic jack landed in the passenger side airbag, and the milk jug of oil I meant to drop off at Autozone that morning hit the back of my seat. It all knocked down back seat like it wasn't there.

F = ma is a mother berkeleyer. You're lucky you weren't decrapitated by a tire iron!

billy3esq
billy3esq Dork
8/5/09 4:19 p.m.
poopshovel wrote: F = ma is a mother berkeleyer.

KE = 1/2 mv^2 is even worse.

Most of the time it's not the m that gets you, it's the v^2.

mad_machine
mad_machine GRM+ Memberand SuperDork
8/5/09 4:19 p.m.

good point on the folding rear seats. I know between my two hatchbacks.. the Saab has the safer rear seat design. When it is locked into place, there is NO moving it out of position.

My BMW.. I can give it a hard tug and half the time it will break lose of it's lock post. All the more reason for me to be working on making the car into a dedicated 2 seater

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