For Your Viewing Pleasure

[gsbaker]

Originally posted by Greg Gauper@Dec 16 2005, 12:25 PM
...To me, all that video shows is that if you don't use the safety equipment properly i.e. snug your belts down properly, proper mounting angle (which BTW is what contributed to Earnharts death), decent racing seat with some lateral support, then the Hans might not be as effective as another device.

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Okay, but the Isaac system works all the time. No ifs, ands or buts.

To the objective observer, the video asks the question, "Why would anyone use a HANS when they can use an Isaac system?"

The belts, BTW, are extremely tight. You are seeing a 180# man X 68Gs = 12,240#. Some of it is belt stretch, some of it is the body changing shape.

[VW16VRacer]

Gregg

What year is the HANS in this test. My HANS is a year old and it has a lip on the outside edge to help keep the seat belts in contact with the frame of the device along with a more agressive textured surface.

I also agree with Greg, the belts IMHO do not look tight, at least not as tight as I run mine. I am also using the Recaro SPG HANS seat that not only has a lot of support but ample wings to add to the safety and support in a offset crash. I have been thinking about adding a sernum strap for just this, but will rethink it after seeing this. I am in no way a P.E. so I could be totaly off on this......


Now I will not argue with you on your design that it works with the belts snug or tight. You are right on that one.

Jon Bonforte

[ddewhurst]

Gregg, while watching the action of the Isaac several times I have a couple questions from my observation.

A. Does the Isaac roller & bracket which is around the harness act as a brake along with the area of harness with the light colored stiching as the helmet end of the Isaac is comming forward & in a downward direction ?

B. During tests is a measurement taken as to the length of Isaac piston rod extention ?

C. What approx distance dose the test shoulder harness stretch or approx how far forward dose the shoulder move ?

D. What approx distance dose the lap belt stretch ?

If these are no answer questions just say so.

Thanks <_<

[gsbaker]

These are all good questions, but they are going to have to wait. We can publish detailed loading data that determines whether a driver lives or dies but the reaction pales in comparison to when we post a simple video of a crash test.

I think our server has melted.

Everyone have a good weekend.

[Dave Burchfield]

Interesting comments by many so far.............I witnessed a test of another device being crashed at the Delphi site in Vandalia. I stood at the sled as the Delphi technicians strapped the dummy in the seat. They spent near an hour fussing over how everything was assembled.

After seeing in person the care and professionalism of the staff at Delphi, it is my humble opinion that there is little, if any chance that ANY test being conducted is not at optimum.

Please remember, this facility tests a host of parts in use by most major auto manufacturers where there are billions of dollars of product liability at stake. They don&#39;t take chances.

Disclaimer: I am not now or ever have been associated in any way with Delphi.

db

[gsbaker]

Originally posted by VW16VRacer@Dec 16 2005, 06:53 PM
Gregg

What year is the HANS in this test. My HANS is a year old and it has a lip on the outside edge to help keep the seat belts in contact with the frame of the device along with a more agressive textured surface.

Ah, then you have the version that came out about a year ago. People tend to refer to it as the 2005 model. The one we tested was older. I&#39;d like to see the videos of the newer one.

I also agree with Greg, the belts IMHO do not look tight, at least not as tight as I run mine. I am also using the Recaro SPG HANS seat that not only has a lot of support but ample wings to add to the safety and support in a offset crash. I have been thinking about adding a sernum strap for just this, but will rethink it after seeing this.

The seat has to help. Be careful with the sternum strap, though. If too high it could choke you; if too low it may not work. People aren&#39;t sure how to tune them. It may be a case of them working great if you don&#39;t hit anything very hard, so why bother.

Of course, with the sternum strap you violate the single point release rule, but don&#39;t get me started.

[gsbaker]

Originally posted by Dave Burchfield@Dec 16 2005, 11:17 PM
Interesting comments by many so far.............I witnessed a test of another device being crashed at the Delphi site in Vandalia. I stood at the sled as the Delphi technicians strapped the dummy in the seat. They spent near an hour fussing over how everything was assembled.

After seeing in person the care and professionalism of the staff at Delphi, it is my humble opinion that there is little, if any chance that ANY test being conducted is not at optimum.

Please remember, this facility tests a host of parts in use by most major auto manufacturers where there are billions of dollars of product liability at stake. They don&#39;t take chances.

Disclaimer: I am not now or ever have been associated in any way with Delphi.

db

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Interesting indeed, Dave. Racers have asked us to test to SFI protocol and do a side-by-side against the HANS device. So we do, and what happens?

Dave is right, everyone. The Delphi lab is very good. We handed them the products, the helmets, a check and said, "Here, run the SFI 38.1 offset for us." Anyone can walk into the lab and do the same thing, and get the same results.

[M. Hurst]

As Paul Harvey sez...The rest of the story.

1. HANS passes the offest test even with only one side of the collar under the belt.

2. They don&#39;t put those big shoulder and head restraints on nextel cup cars for looks.

3. Those belts are tight, the forces are big.

4. So far no test data from Isaac on the straight frontal test.


Opinion: In conditions without seat head restraints, the Isaac would probably perform better than HANS in offset tests, especially at greater angles.

[gsbaker]

Well said.

So what is it you believe a HANS device does better than an Isaac system? Seriously, I&#39;m not trying to sound like a wiseguy, and we are aware that a HANS with a 4-belt harness will probably outperform an Isaac system in a pure frontal crash.

[Knestis]

... First off, those belts do not seem to have been snugged down sufficiently.

I don&#39;t know about this test individually, but my understanding is that Delphi staff do the testing and I would assume that they understand the importance of tight belts.

Second, most of us do not race on a flat metal plate for a seat lacking any lateral support, such as what was tested. We racing on racing seats which do provide some lateral support. Some better than others.

You are onto something VERY important here, Greg. This is one major shortcoming of the SFI test. This is supposition on my part but, as someone who gathers data for a living, if I were designing the 38.1 protocol and knew that evidence suggested that I could expect strong interaction effects between seats, harnesses, and H&N systems, I might leave the seat out of the equation for the sake of "fairness." Test protocols like this require - first and foremost - repeatability. (This is why I strongly doubt that harnesses were looser in either test.) If Delphi used, say a RECARO SPG Racer like mine, it would be possible for people to accuse the test of being biased against a particular H&N system, the design of which for whatever reason doesn&#39;t jive with that seat.

Third, even though the belts slipped on the Hans, look very closely at the video and compare the total amount of head movement and neck travel of the Hans user to the non-Hans user. The Hans user still had less head and neck travel, inspite of not being used correctly i.e. the belts too loose and slipping out.[/quote]
Again, I don&#39;t know the numbers involved in these specific tests but remember that it isn&#39;t MOTION that kills you. What we really care about is the reduction of the loads imposed on the connection between noggin and neck.

... if you don&#39;t use the safety equipment properly i.e. snug your belts down properly, proper mounting angle (which BTW is what contributed to Earnharts death), decent racing seat with some lateral support, then the Hans might not be as effective as another device.

Abso-damn-lootly. The basis of our complaints with SFI 38.1 is that it tests H&N systems to a minimum standard, completely out of context of the real world of real racers, in real race cars, hitting real stuff, real hard. This is what headrestraint.org is responding to. Instead of a standard, the sole purpose of which is to indemnify sanctioning bodies and manufacturers, we should have a way of reporting head-load force reductions in a variety of conditions, in a variety of crashes.

I should be able to ask a H&N manufacturer how well their system works with MY seat, in MY type of car - and they should have some motivation to find out, so they can provide me and other safety consumers with that information. As it is, SFI requirements by sanctioning bodies pose a huge DISINCENITVE to testing any protocol besides 38.1

Why, for example, would any manufacturer in the current environment want to test a broadside crash into a tree (all but certainly the most fatal situation for rallyists), when they have nothing to gain by doing so? Why don&#39;t Rally America and NASA Rally demand this kind of testing? Because the manufacturers and SFI have given them an easy out with 38.1. Who suffers? Racing consumers, who get a dumbed-down "yes/no" test and a list of "approved" devices - tested against a protocol that SFI itself tells us (at its lawyers&#39; prompting, no doubt) shouldn&#39;t be used to compare the performance of systems.

K

[Bildon]

I agree with the others that neither belt appears to be tightened properly. What also concerns me even more is that the belts on the Hans dummy are 2" to 3" looser than on the ISAAC dummy. You can see this in frame #1 by looking at the metal adjusters relative to the lettering on the T-Shirt.

Where is the real SFI test data for both tests? Or was this only a private Delphi test? This is a life and death matter and all the facts should be laid out for all to see. This SFI test data must have been published if these tests have been performed on the HANs and ISAAC, no?

I would like to hear the HANS viewpoint as this is scary stuff.

[Knestis]

Again, likely in the interest of repeatability, I&#39;ll bet that the testers didn&#39;t remount the harnesses to put the adjusters in the right place on the HANS dummy&#39;s chest. Remember that the HANS frame is going to take up some room - the same as would happen if one put a thicker-chested person in the harness, where it had been adjusted for, well, me and the adjusters will naturally ride higher up toward the collarbone.

Yet ANOTHER limitation of the test protocol: The same dummy gets used, so the same harness adjustments get used.

K

EDIT - The further issue is that there is no such thing as "SFI test data." The protocol reports dichotomous data (or binary, if you choose), like pregnancy test - a system either passes or fails. (And I&#39;ll let you decide which is which, in the pregnancy analogy!)

[Bildon]

>> there is no such thing as "SFI test data."

Oh come on! Just because the product is rated on a "pass-fail" basis doesn&#39;t mean their wasn&#39;t a &#39;shload&#39; of data generated to reach that conclusion.

I found this with a little research.
http://www.ogracing.com/files/SFI_testresults_web.jpg

Would like to see more data on the test in the video.

[lateapex911]

I am REALLY doubtful that the tests were conducted with the belts "loose" as has been opined here. That&#39;s just basic science...and any test conducted by a facilty such as this, HAS to be a bit more advanced than "basic science"....

This whole SFI thing is VERY scary....it really is a massive diservice to us, the racers...we are all led down this path that results in the companies and the SFI padding their pockets, and the racers assuming they are protected in the best manner possible.

Add to that TV commentators with the inevitible comment after a bad crash. "Good thing he was wearing a HANS...probably saved his life"...riiight..like they have a CLUE to the actual forces imparted on any driver in any crash..

It is unfortunate that the HANS in this test wasn&#39;t the current model, and that "realspeed" video wasn&#39;t availble so we can see how it happens in real time.

[Knestis]

Sorry - I wasn&#39;t clear. SFI doesn&#39;t PUBLISH data, even though there is indeed a lot of it squeezed out of the process.

K

[gsbaker]

Okay, several things quickly:

1. We have a real time video, shot with a camcorder on a tripod. Someome please remind me to get it posted if you don&#39;t see it in a couple of days. Rather dull, actually, until one considers 1/2 million pounds of thrust runs the sled from a dead stop to 40+mph in about 30 inches. No audio though.

2. We received the final package of data on Wednesday, so we&#39;ve had only two days to work with it. The first priority was the video and enough of a review of the data to offer a verbal summary. There was much more to this test series than what has been presented here. In six months at two labs (Wayne State being the other) we ran a total of 4 crash tests on three designs to put some meat on this whole single-point-release/SFI issue.

We are swimming in data. Video too. Five cameras. It should all be enroute to headrestraint.org soon.

3. Everything about this test is very precise, including the belts. The techs spent nearly an hour getting the dummy prepped properly. With the HANS device, which they have hit many times, the belt adjusters are supposed to be at a particular location relative to the bottom of the HANS yoke (don&#39;t know why). Also, the HANS requires more belt so everything had to be reset. The belts are tighter than a driver could ever load them.

[Knestis]

Originally posted by gsbaker@Dec 18 2005, 06:21 PM
... With the HANS device, which they have hit many times, the belt adjusters are supposed to be at a particular location relative to the bottom of the HANS yoke (don&#39;t know why). Also, the HANS requires more belt so everything had to be reset.

Interesting. Exactly the opposite of what I guessed.

K

[gsbaker]

Dave,

Sorry it took so long to reply.

Originally posted by ddewhurst@Dec 16 2005, 07:14 PM
Gregg, while watching the action of the Isaac several times I have a couple questions from my observation.

A. Does the Isaac roller & bracket which is around the harness act as a brake along with the area of harness with the light colored stiching as the helmet end of the Isaac is comming forward & in a downward direction ?

No, there is enough clearance for the double-thickness of belt to pass without any friction. I&#39;m glad someone spotted that. Now you can see why we suggest a minimum length of free travel in front of the belt connector. If you hit something hard enough you may need it.

B. During tests is a measurement taken as to the length of Isaac piston rod extention?

Yes. It was extended too far, over 60% of travel. Also, the helmet mounts are too far to the rear.

C. What approx distance dose the test shoulder harness stretch or approx how far forward dose the shoulder move?

I&#39;d have to measure it off the lateral camera.

D. What approx distance dose the lap belt stretch?

Same answer. Sorry, all that is at work.

If these are no answer questions just say so.

Thanks <_<

Anytime

[tderonne]

Quick comment, a little off topic, but relevant to some comments above.

FIA seats are tested to survive a 15 to 20 g load.

What g load did these tests see?

(A few have mentioned the Recaro SPG seat. It meets FIA.)

[gsbaker]

Originally posted by tderonne@Dec 18 2005, 10:24 PM
Quick comment, a little off topic, but relevant to some commenst above.

FIA seats are tested to survive a 15 to 20 g load.

What g load did these tests see?

(A few have mentioned the Recaro SPG seat. It meets FIA.)

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Tim,

The sled is capable of ~80Gs, but the spec calls for a nominal peak load of 68Gs, and the computer controls that well.

Seats are the issue in pure lateral testing, i.e. 90 degree offset. There are different styles, so some debate as to which is most representative. Then you have to remove everything above the shoulders to isolate the contribution from the H&N restraint. Plus they tend to blow up.

That&#39;s one reason we like this 30 degree offset test. The lateral component alone is 34Gs (68 x sin(30)) and the lateral head torque is measured independent of other head loads, so we get a very good idea of how well the product protects the head against side loading, with or without a seat. We figured we would do well in this measure, but really got an early Christmas present--an 85% reduction in lateral head torque. A real double take.

And the left shock reaction that reduced the lateral torque held the belt on. What&#39;s that old saying? I&#39;d rather be lucky than good.