Some great safety info

This is off of a pdf file from Schroth:

Harnessbelts & Rollovers & RollbarsA world-renowned panel of SAE vehicle safety experts from GM, Daimler-Chrysler, Ford, University of Michigan, and a leading harnessbelt manufacturer, addressed this issue at the PRI show in December 2002.They unanimously stated:

1.The greatest risk of serious injury in a rollover is head contact with the door frame or other things outside the vehicle. A proper 4+ point system will greatly reduce the potential for such contact.

2.Serious injuries in rollovers are very seldom due to the collapse of the roof on the occupants.

3.Use of rollbars in primarily street driven cars could greatly increase risk to driver and passengers in daily driving.

HERE ARE THE FACTS…

Most serious driver injury or fatality in rollover accidents (where 3-point factory systems are worn properly) occurs from head contact with the doorframe resulting when a car flips over and crashes to the left edge of the roof. (Passenger injury when to the right edge of the roof).

��Rollovers result in loads of 10g to 35g deceleration to the bodyeliminating the possibility of controlled “escape”by an occupant to “duck”from the collapsing roof.

��Such deceleration will partially eject the occupant from a 3-point factory belt.

��The endless loop of webbing from the factory 3-point system will allow the body to move 2”to 4”upwards in the seat. This can allow significant contact with the doorframe.

��Deceleration forces to the head in contact with the doorframe can easily exceed 300g

��Vehicle safety systems are designed for 99 percentile accidents.Properly certified and installed 4-5-6-point harnessbelts significantly increase vehicle safety in 99% of likely accidents including rollovers.

TURBO2GO said:

This is off of a pdf file from Schroth:

Harnessbelts & Rollovers & RollbarsA world-renowned panel of SAE vehicle safety experts from GM, Daimler-Chrysler, Ford, University of Michigan, and a leading harnessbelt manufacturer, addressed this issue at the PRI show in December 2002.They unanimously stated:

1.The greatest risk of serious injury in a rollover is head contact with the door frame or other things outside the vehicle. A proper 4+ point system will greatly reduce the potential for such contact.

2.Serious injuries in rollovers are very seldom due to the collapse of the roof on the occupants.

3.Use of rollbars in primarily street driven cars could greatly increase risk to driver and passengers in daily driving.

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Thanks for that post. I have often thought that these would be the facts of most rollover cases, but I have been reluctant to enter the fray on this topic as so many people have offered so many varying "facts".

It seems obvious to me that any un-padded roll bar in a car would be more of a danger to occupants than protective. And I couldn't quite understand how a 4-pt. harness would stop a passenger from avoiding neck injury any more than a conventional 3-pt lap/shoulder belt.

I rarely (if ever) use my harness on the street (just once in the last 4 years or so), but I appreciate it during track use.

Again, thanks for posting.

ChopsJazz said:

It seems obvious to me that any un-padded roll bar in a car would be more of a danger to occupants than protective.

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I am pretty sure (although the wording is vague) that what they meant is the way most rollbars are installed in show cars for the street. Improperly installed bars that come loose, no helmet, no harness belts. Just you and a rollbar floating around loosely in a car. That is what they meant. A properly installed rollbar worn with a harness should be much safer.

The main point of emphasis from what I read is that the factory 3 pt allows way too much movement vertically and so your head makes contact with all sorts of stuff. A pillar, B pillar, door frame, rollbar. Even a modest 4 point harness properly installed and worn holds you down by your shoulders and keeps your head from banging into something like the frame.

Then the issue left is your neck which is vulnerable, and this seems like one of the most up to date solutions:



Below is some very interesting commentary forwarded to me by Jim (CL65captain) from a guy at US race gear regarding neck restraints and HANS devices:

If you are running a racing harness I fully agree that you need a head and neck restraint. If you get in an accident, your belts stop your body and your head keeps going. This can result in a variety of injuries ranging from whiplash to a fatal basal skull fracture. Most people don't realize that a rapid change in velocity as low as 35mph can result in a fatal injury.

Head and neck restraints are designed to prevent these injuries. I sell the Hybrid devices from Safety Solutions and chose not to sell the Hans for several critical reasons. I believe that the Hans is obsolete and I will not sell a customer something that I would not wear myself. I wore one for 8 years until the Hybrid came along. I feel the Hans was a good first efort but has several critical deficiencies that have all been addressed by the Hybrid devices.

1. The primary reason is that the Hans can only function if it is held tightly to your body by your shoulder straps. Because of this, it works best in head on collisions. ( This can be verified by looking at the attached graph of SFI sled test results showing neck tension ). The performance of the Hans drops off as the angle of impact increases because your body is going to move in the direction of the impact and your shoulder belts can't go with you as they are attached to the cage or harness bar. This causes the shoulder belt on the side away from the impact to slide off the Hans either partially or completely. Something that has been kept quiet is that the Hans is only designed to work up to 45*. In a side impact it will not prevent a basal skull fracture. Have you noticed that GrandAm mandated right and left side head nets several years ago? it is because of this. The only reason Grand Am and NASCAR cup drivers aren't wearing a Hybrid is because they are both owned by the France family and they want a large payment to certify the devices. They are used in NASCAR truck racing and have almost completely replaced the Hans in top levels of drag racing such as Funny Car and Top Fuel Dragsters ( 300+ mph ). This is the most important difference: the Hybrid devices provide 360* protection. In the same side or high angle impact where you are at risk with the Hans, you are protected with the Hybrids. This can be a life or death decision. *Also, if you are going to wear a Hans, you need a special seat.

2. Because the Hans is dependent upon your shoulder straps, it can be a single impact device. In a hard impact you will come out of your seat and stretch your shoulder belts, or they may break. At this point the Hans is not held tightly to your body and your protection is diminished or gone in following impacts. Conversly, the Hybrid is attached to your body and will continue to protect you until you get out of the car and take it off. You are protected even if your shoulder straps break.

3. When the devices act to restrain your head in an accident they must contain a lot of force trying to move your head forward ( 1200 lbs in the SFI sled test ). The Hans does this by using your chest for leverage. This has resulted in broken collar bones and ribs. Their response in that this is better that dying, which it obviously is. The Hybrids use the straps as load pathways and tie into your belts to protect your neck without harming your body.

4. Look at the attached table of SFI test results. In the same 30* impact the Hans allows almost 25 times the force on your neck as the Hybrid does, 494 vs 22. The Hans may prevent a basal skull fracture but with a 494lb jerk you may have other injuries. If the force is kept under 200lb, you will be uninjured.

I hope this is clear. The best thing would be to come down to the shop and I can show you the difference in person. Also, you can call me at the number below with any questions.

Craig Friesinger, U.S. Race Gear
513-300-4221
www.usracegear.com

TURBO2GO said:

I am pretty sure (although the wording is vague) that what they meant is the way most rollbars are installed in show cars for the street. Improperly installed bars that come loose, no helmet, no harness belts. Just you and a rollbar floating around loosely in a car. That is what they meant. A properly installed rollbar worn with a harness should be much safer.

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I was referring to rollbars in a street cars with occupants' heads ~3" away. No harnesses, just 3-pt. shoulder belts. I am concerned about the increasing popularity of rollbars in street cars.

Grand-Am and NASCAR (as well as most proper formula cars) have substantial side-impact head restraints and only need the frontal impact protection of the HANS. In said cars, the Hybrid probably doesn't serve any competitive advantage in its side-impact protection because the head rests are the main component for protection.

Sure the Hybrid might be safer in an side impact than the Hans in an open-seat design, sure a 6pt harness is better than 5, and 5 better than 4, and 4 better than 3, sure a full-surround seat is better than a racing bucket and a racing bucket safer than a stock seat, and sure a roll bar is safer with the above, but how far do you want to take it? There are tons of club racers who don't wear Hans devices, and even more HPDE drivers who don't have any of the above. I'm all for safety but there becomes a compromise for everyone's individual goals and needs and what they are willing to sacrifice for it.


0.02

Yeah, this was refreshing to see. I've been heckled a few times for having harnesses in my MR2 with no roll bar/cage, and most cite the "you can't duck" argument dispelled above. I paid enough attention in physics to be comfortable with my setup, but you know how some people get....

Yeah this information goes completely against a lot of what we assumed on earlier threads. Basically the idea that in a crash you have any sort of control over your body is ludicrous. The guys that assumed they were safer with a harness that a seatbelt were right and this contradicts the belief at most DE schools that a proper harness without a rollbar is less safe than 3 point belts.
Basically 3 point belts kind of blow. Probably a huge part of why they are OEM is for convenience. Honda or Toyota can't ask the public to strap on a harness to go to the grocery store. And it's probably not necessary but that doesn't mean it is not safer. The issue with the NSX harness bar is that it is mounted to relatively weak points on the chassis and it can come loose and be a hazard itself. Still, having this info I'd say people with a harness bar are safer overall than people with the stock safety system.

I am waiting for Tedro to jump in, surprised he hasn't responded yet ......... :tongue:


Here is the short hand perspective which I have said elsewhere. It is all a matter of risk assessment. The percentage of drivers having a roll over in street driving is so minimal that a 3 point OEM seat belt is perfectly fine and safe. Manufacturers have made that determination for you.

The percentage of roll over in HPDE vs. say collision with a wall is debatable for it depends in on how the HPDE is run, the driver's adrenaline, and how much risk the driver takes with what he has. It appears that many who attend HPDE have concluded (either knowingly or not) that the risk of roll over percentage is less - if so, then indeed a head restraining safety is more important with 5/6 point harness. And this is not a debate that is winnable. YMMV.

TURBO2GO said:

Honda or Toyota can't ask the public to strap on a harness to go to the grocery store. And it's probably not necessary but that doesn't mean it is not safer. The issue with the NSX harness bar is that it is mounted to relatively weak points on the chassis and it can come loose and be a hazard itself. Still, having this info I'd say people with a harness bar are safer overall than people with the stock safety system.

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Keep in mind if you strap on a harness, you must control the head through use of a HANS or equivalent or you have unquestionably made yourself less safe. And you must be very careful about the design and installation of your chosen restraint system to also be sure you haven't worsened your safety situation.

I chose to go down the HANS and harness route without a rollbar after much reading, deliberation, and thinking about the situation for myself, as everyone who engages in this higher risk activity should do.

Liquid said:

Keep in mind if you strap on a harness, you must control the head through use of a HANS or equivalent or you have unquestionably made yourself less safe. And you must be very careful about the design and installation of your chosen restraint system to also be sure you haven't worsened your safety situation.

I chose to go down the HANS and harness route without a rollbar after much reading, deliberation, and thinking about the situation for myself, as everyone who engages in this higher risk activity should do.

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Having been in severe crashes (on and off track) as a driver and passenger of street cars with 'tuner' 4-pt harnesses, IMO (opinion) I like a 4pt harness more than the stock 3-point. there's more surface area to distribute the load across your body as well as no 'slack' that the 3pt harness allows which prevents further injury.

I dont believe a harness would be any worse than a 3-pt belt without an airbag because your body will eventually stop one way or another and so will your head.


0.02

TURBO2GO said:

This is off of a pdf file from Schroth:

Harnessbelts & Rollovers & RollbarsA world-renowned panel of SAE vehicle safety experts from GM, Daimler-Chrysler, Ford, University of Michigan, and a leading harnessbelt manufacturer, addressed this issue at the PRI show in December 2002.They unanimously stated:

1.The greatest risk of serious injury in a rollover is head contact with the door frame or other things outside the vehicle. A proper 4+ point system will greatly reduce the potential for such contact.

2.Serious injuries in rollovers are very seldom due to the collapse of the roof on the occupants.

3.Use of rollbars in primarily street driven cars could greatly increase risk to driver and passengers in daily driving.

HERE ARE THE FACTS…

Most serious driver injury or fatality in rollover accidents (where 3-point factory systems are worn properly) occurs from head contact with the doorframe resulting when a car flips over and crashes to the left edge of the roof. (Passenger injury when to the right edge of the roof).

Rollovers result in loads of 10g to 35g deceleration to the bodyeliminating the possibility of controlled “escape”by an occupant to “duck”from the collapsing roof.

Such deceleration will partially eject the occupant from a 3-point factory belt.

The endless loop of webbing from the factory 3-point system will allow the body to move 2”to 4”upwards in the seat. This can allow significant contact with the doorframe.

Deceleration forces to the head in contact with the doorframe can easily exceed 300g

Vehicle safety systems are designed for 99 percentile accidents.Properly certified and installed 4-5-6-point harnessbelts significantly increase vehicle safety in 99% of likely accidents including rollovers.

Click to expand...

Well, yeah. Keep in mind this was way back in 2002 - before the advent of side airbags.

As Hrant said rollover events are less frequent than frontal, rear or side collisions. A 3pt belt and basic frontal airbag are sufficient to mitigate any potential injury from 99% of the accidents you would see on the road at a 95% confidence factor. It's hard enough to get some folks to buckle up with one click, even fewer will do it with a 4pt system.

However, if you do have a rollover, then yes, a 4, 5, or 6pt harness would be better than a 3pt. The next passenger vehicle safety feature will probably be a headliner airbag just for these events

stuntman said:

Having been in severe crashes (on and off track) as a driver and passenger of street cars with 'tuner' 4-pt harnesses, IMO (opinion) I like a 4pt harness more than the stock 3-point. there's more surface area to distribute the load across your body as well as no 'slack' that the 3pt harness allows which prevents further injury.

I dont believe a harness would be any worse than a 3-pt belt without an airbag because your body will eventually stop one way or another and so will your head.

0.02

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Actually, the 3pt belt lets the upper torso pivot forward slightly when decelerating. Combine that with the OEM belts stretching slightly (as opposed to racing belts with no give), and this little extra distance helps reduce the g-forces and can mean quite a difference in what the final injuries could be.

Dave

Mac Attack said:

Actually, the 3pt belt lets the upper torso pivot forward slightly when decelerating. Combine that with the OEM belts stretching slightly (as opposed to racing belts with no give), and this little extra distance helps reduce the g-forces and can mean quite a difference in what the final injuries could be.

Dave

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You don't want there to be any slack in the torso or stretching of the belts. The tighter the belts the better, slack does not 'cushion' the impact. Any give in the belts accentuates the whiplash effect and injury.

Mac Attack said:

Actually, the 3pt belt lets the upper torso pivot forward slightly when decelerating. Combine that with the OEM belts stretching slightly (as opposed to racing belts with no give), and this little extra distance helps reduce the g-forces and can mean quite a difference in what the final injuries could be.

Dave

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Dave that makes NO SENSE to me. Is this personal opinion or based on some sort of data? How does your torso moving forward an extra 6" lessen the impact at all? If anything my basic knowledge of physics says it would be worse.

stuntman said:

You don't want there to be any slack in the torso or stretching of the belts. The tighter the belts the better, slack does not 'cushion' the impact. Any give in the belts accentuates the whiplash effect and injury.

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Yes, this makes sense to me. Billy please PM me your email address. Thanks.

Good info Dave. Btw, ALL belts stretch upon impact. Even the 5 point Harness on my Spec Pinata stretches 4-6" upon frontal impact!

stuntman said:

You don't want there to be any slack in the torso or stretching of the belts. The tighter the belts the better, slack does not 'cushion' the impact. Any give in the belts accentuates the whiplash effect and injury.

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I never said "slack" as you stuntman - there is a difference between slack and a more controlled stretch over the short time when you started decellerating. With a 3pt OEM belt, limited pivoting of the upper torso combined with the substantial OEM belt stretch is not slack.

You're right for racing where you have supplemental head restraints or a neck cushion, and various hard points (cage, etc) close to your helmet. Sure, you want your body planted in that scenario.

However, for street use and occasional HPDE use where folks have removed the airbag-equipped steering wheels rolleyes and use a more rigid harness system, then you do want some give. Thank you for correcting me NSXLuvr as yes, all belts stretch to some extent depending on how many restraints you have, their dimensions, and their materials. That's why after an accident, you throw them away as they have been stretched and material properties changed as they quickly heated up.

If you increase the distance it takes for your upper torso/head to come to a complete rest when you hit something with a controlled belt stretch or upper torso pivot, then the average deceleration your head sees is less than if your head came to a sudden stop. That's the 300gs the Schroth file mentioned if you smacked your head on an unpadded rollbar during a rollover.

I'm not talking out of my rear-end here. 15 years ago I helped with a 3-D virtual-reality vehicle crash simulator at Argonne National Labs.

I felt the need to throw my $0.02 in here as the article originally posted by turbo pointed out the benefits of a 4, 5, or 6pt harness in the event of a rollover. However, it may actually be more detrimental on the street (where you don't wear a helmet or neck restraint system) and are involved in a frontal accident where your upper torso is not free to pivot, your belts are more rigid, and even worse, some folks may have removed their airbag.

But maybe Turbo had the right idea years ago that we should all start wearing our helmets and restraint systems on the street.

Dave

Dave I brought up this thread to have a dialog and give information. Why are you being sarcastic with me? I never said people should drive with helmets and harnesses on the street. I asked if it was legal if someone did.

The point of this post was that we maligned a lot of guys for not having a rollbar but having a harness, but the stats here prove they were better off in MOST situations. You bring up the fact that this was in 2002 and that since then we have side airbags but that is not really relavent since no NSX has side bags or curtain bags.

Mac Attack said:

I never said "slack" as you stuntman - there is a difference between slack and a more controlled stretch over the short time when you started decellerating. With a 3pt OEM belt, limited pivoting of the upper torso combined with the substantial OEM belt stretch is not slack.

You're right for racing where you have supplemental head restraints or a neck cushion, and various hard points (cage, etc) close to your helmet. Sure, you want your body planted in that scenario.

However, for street use and occasional HPDE use where folks have removed the airbag-equipped steering wheels rolleyes and use a more rigid harness system, then you do want some give. Thank you for correcting me NSXLuvr as yes, all belts stretch to some extent depending on how many restraints you have, their dimensions, and their materials. That's why after an accident, you throw them away as they have been stretched and material properties changed as they quickly heated up.

If you increase the distance it takes for your upper torso/head to come to a complete rest when you hit something with a controlled belt stretch or upper torso pivot, then the average deceleration your head sees is less than if your head came to a sudden stop. That's the 300gs the Schroth file mentioned if you smacked your head on an unpadded rollbar during a rollover.

I'm not talking out of my rear-end here. 15 years ago I helped with a 3-D virtual-reality vehicle crash simulator at Argonne National Labs.

I felt the need to throw my $0.02 in here as the article originally posted by turbo pointed out the benefits of a 4, 5, or 6pt harness in the event of a rollover. However, it may actually be more detrimental on the street (where you don't wear a helmet or neck restraint system) and are involved in a frontal accident where your upper torso is not free to pivot, your belts are more rigid, and even worse, some folks may have removed their airbag.

But maybe Turbo had the right idea years ago that we should all start wearing our helmets and restraint systems on the street.

Dave

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I completely understand what you are saying but I must respectfully disagree. Despite the seat differences, head restraints, etc... in race cars compared to HPDE street cars, I still prefer and think a 4-pt harness is safer than a stock belt and airbag. Even in un-caged, no head-restrainted cars, the tighter you can make the belts, the less injury will be incurred. This is a common theme stressed in motorsports and I would have to agree from (unfortunately) personal experience.

Your thought process makes complete sense but from my personal experience and from being in motorsports, I believe a simple 4-pt is safer.

I remember reading years back that production cars were attempting to go to a 4-pt harness system but due to its added restraint, lack of movement from a comfort standpoint, it was deemed to be considered too much of a hassle that would deter more people from using their seat belts and thus not implemented. Someone should try to find that article...

1) I'm pretty sure the scientific consensus is that if you hit an immovable object (wall/large vehicle coming the other direction) head-on with no other directional travel in the car, a 3-point + airbag is superior to a solid harness + NO HANS or airbag. The reason is that the stretch of the 3-point along with the airbag will limit the deflection of the head/neck relative to the torso (i.e. the Dale Earnhardt injury). The harness, while it does stretch some, still holds the torso very firmly, while not restraining the forward movement of the head. It's this chin-to-chest whip that can damage the vertebrae and brain stem.

1a. I do not know if anyone's looked at a harness + an airbag.

1b. That said, many sports car manufacturers sell(/sold at some point) their cars in Europe/Asia with 4/5 point belts as OEM/options.

2) In pretty much any other scenario: backing into a wall, glancing off of something, flipping, side-on, etc. the thing that most limits your likelihood of flying around the cabin is going to be best (i.e. a harness).

3) Obviously the ideal is a harness with a HANS/equivalent regardless of what other protective devices are present in the car based on this article.

2. Wearing a Hans device without a roll cage and having a roll over in which case there would be no way to roll your head out of the way of a collapsing roof.

Coz, did you read the beginning part of this thread??! If you mean "ducking" out of the way, schroth is saying that is fantasy. And even on rollovers only a tiny fraction is this scenario. You need to have a head restraint, either HANS or something like the Hybrid above.

The Hans devise is an awesome piece of technology that has saved many lives. It's great its mandated in many racing series.

Devils advocate: How many crashes in the history of auto racing has their been and how many of them (vast majority) have resulted in deaths due to no Hans device?

IMO harnesses (even without a hans device) is probably safer than any 3-pt configuration + airbag short of modern 20-airbag luxury cars. Airbag technology has come a long way thus, our NSX's archaic airbag is probably more dangerous than it is safe.



0.02

Coz said:

I have a G70-DeFnder, but usually don't wear it.

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I read both your replies and don't understand why. What is your rationale? You think that being in a harness without it is safer in ANY WAY??

Are we on the same thread? LOL... for the third time I am pointing out the information above. In a rollover you are not ducking anything anywhere. You will most likely not have ANY CONTROL over your body. Even then, roof collapse will probably NOT be your source of injury. That's what this whole thread is about but you keep saying the same thing? :tongue:

Nope, not anymore.
Have a nice day.

TURBO2GO said:

Are we on the same thread?

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If you just tip the car on it's roof (you drove up a bank sideways and rolled, etc.) sure, you'd be able to move your head, but in that case (well first of all, the roof is not going to crush), however although you may be able to duck your head, unless the seatbelt locks quickly, you're still likely to come in contact with the roof as a result of slipping out of the 3-point belt.

If you roll your car hard enough and land in such a way for the roof to crush, you're probably boned regardless. You'll either be rag-dolled around the cabin if not slung entirely out of a 3-point belt, or the roof will crush onto your head if you're in a harness/fixed-back seat (assuming no bar obviously) because you will have no control over your cranium. However, as the article states most injuries from rolls result from your head hitting the side of the door frame...so harness FTW in a roll.

Billy makes a good point regarding the age of the airbags in some of these cars. Hell, I'm not even sure mine would work like its supposed to given it's age and the corrosive environment in which my car spent much of its life (north-east).

Either way, no point debating it to the point of exhaustion. The information is here, and people will do with it what they will.