HANS Device

[Teletubby]

I believe that some of the negative views being expressed here are the result of 'chinese whispers' and that some of the negative feedback about HANS is due to a lack of understanding and incorrect fitting.

[Teletubby]

Sam, with regard to floorpan deformation, I'm inclined to agree with Johnw, seats coming adrift is more of a worry. Whilst floorpans (and indeed whole bodyshells) may (and do) deform I'm not sure what your question is with regard to the belts and HANS?

[ss_collins]

tubbs (where's edward?) my question is what happens to Hans if the seat moves, breaks or even detatches...? the driver then moves within the belts but attached to a Hans what occurs - I don't know the answer to this one and can't get the run through right in my mind.

John - yes please - by e-mail if you want to sam_collins@ipcmedia.com (any of you with ideas feedback or general lunacy feel free to email me btw)

[dtype38]

Originally Posted by ss_collins

my question is what happens to Hans if the seat moves, breaks or even detatches...? the driver then moves within the belts but attached to a Hans what occurs - I don't know the answer to this one and can't get the run through right in my mind.

Sorry SS, but this thread has been going some time now, and every time someone comes up with an answer for one of your concerns you seem to invent a new one. If you want genuine answers, then maybe you should think each senario out fully and be specific about your questions rather than just throwing up potential problems....

But as you've asked.... the situation of the seat moving or the chassis/shell flexing is specifially addressed by the fact that the HANS restraints are located by your shoulders and not by the car. That means that, within the limits of your harness acting as a restraint for you body, the HANS device maintains the relationship of your head relative to your shoulders regardless of where your seat/chassis/body is thrown. Should the accident be so severe that your harness is not actually in a postion to restrain your upper body, then I think you probably have more things to worry about than how effective your HANS device is

[Teletubby]

Sam, think about the question, if the seat breaks then you are likely to have bigger worries than the HANS! I will endeavour to find out what the accepted wisdom is but to be honest you could carry on like that forever.......What happens to the HANS if a comet lands on you while wearing one? I'm not trying to belittle your viewpoint, quite the opposite, I find your approach to safety interesting but I feel that some of the arguments are a little weak, especially if you have ever seen anybody who has suffered a BSF.

If you are concerned that issue with seats are that likely then I suggest that you speak with a Scrutineer or the MSA and express your worries, I would suggest that good car preparation could alleviate a number of incidents but if you have an accident then I firmly believe that HANS will save your life. A simple study of the device and an understanding of the mechanics of an accident and the mechanism of injury would show that clearly.

[Woolley]

Originally Posted by Teletubby

especially if you have ever seen anybody who has suffered a BSF.

...or a broken neck (three times) or a fractured jawbone (in 5 places from hitting the steering wheel with an open-face helmet). Not pretty, not nice to deal with. That's why I'm in favour of things that will save your life.

As a rhetorical question, how many drivers have been at a meeting where any of those sorts of injuries have happened, and particularly where you saw the aftermath? It's too easy to adopt the 'it won't be me' attitude when you're not really involved in serious injuries, but after 18 years marshalling, I've seen enough to know I wouldn't risk it if I were driving. Rescue crew will be even more forthright I imagine, as they deal with much more than I do.

[chezza]

One of the problems is that all accidents are different no matter what models are produced and scenaros are run they real accidents never work out the way they should.

[R59]

I'm sure that the FIA safety commission have looked into it a bit, and not just looked at the HANS website.

I'm also sure that the NASCAR decision to go for HANS only is based on the effects/injuries of their many drivers (don't forget there is more than the NEXTEL cup under the rule of NASCAR)

Rob.

[ss_collins]

I was in an accident 3 weeks ago where the seat shifted 10 cm across the car and I moved within the belts significantly... I am applying Hans to this accident and am only asking what happens in that scenario. if the seat and the belts and the driver all move independently as happened - what happens to the Hans, because seat breakages and movement are more common than you may think.

Now a hans would have had little effect either way on the injuries I recieved (tree to the head at some speed) other than - I feel leave me more exposed... (I ducked when I saw it coming!). It whould have hampered escape from a car that was fhad fluids pouring out of it no doubt. but in another scenario it could have saved my life - never have I questioned its anti BSF ability... but in rallying - trees are far more common than BSF.

I have no axe to grind against the device but I do have marked concerns - which I have voiced. My concerns have not been adressed as yet - niether have other peoples who perhaps are less vocal. Now from the safety challenge I have heard some ideas on how hans could be improved or totally reworked... these are most interesting. If you think I'm all talk - wait until we start crash testing!

[ss_collins]

I'm sure that the FIA safety commission have looked into it a bit, and not just looked at the HANS website.

To this I repeat my earlier comment - it may be without significance mind. But would point out my general point that perhaps Hans is not the best solution.

interestin point - to be able to apply for safety research funding from the FIA you first have to join the FIA safety institute which costs around £10,000.

[Al Weyman]

Blimey SS where did you find a tree to hit, was it Oulton Park? A GT40 driver I knew, Paul Hawkins did that there in the 60's and never lived to tell the tale, I wonder if Hans would have saved him.

[johnw]

Originally Posted by chezza

One of the problems is that all accidents are different no matter what models are produced and scenaros are run they real accidents never work out the way they should.

Not a lot of point in Sam doing his crash testing then?

[chezza]

Sam managed to hit not one tree but several, rolled about 6 times at about 8 feet in the air. This was at a rally at Longcross in Surrey.

John, what I mean is that you can test what you think is every eventuality in the crash lab...but in real life there will always be one accident that is different.

Look at Sams last accident...all the models said he and Chris (the driver) should be dead...but unless I had dinner with a ghost last night they are most certainly alive...thus proving my above statement.

[Woolley]

Ouch, sounds nasty.

The seat shifting bit is, I suspect, not significant with the HANS. In fact the seat breaking away would help to disperse energy (depending on what you hit afterwards) and the belts that restrain the driver and the HANS should be fastened to the cage. In this case, the HANS would at worst have made no difference, and at best, still held by the belts, provide some assistance (perhaps reducing the severity of the impact with the tree?) Don't understimate how far you head will have moved towards the tree in the impact - if your seat can break, I guarantee that ducking or trying to restrain your head by muscle power alone will have had no physical effect whatsoever. Remember for instance that Hakkinen sufferred sufficient force to hit the steering wheel with his face when he probably couldn't have reached it with the top of his helmet from his normal strapped in position.

I do share your concern that the HANS could make it more difficult to escape from a car without assistance, and in rallying this is a much more significant consideration where assistance is less immediate. I also suspect that the type of incident for which the HANS is designed - the sudden stop - is not so common in rallying. You have to hit an obstacle failry head on to do that, whereas it's far more common to see a rally car bouncing and rolling (as in Sam's example) and this dispels energy with each impact reducing the maximum force transmitted to the occupants at any one time.

Anyway, and most importantly, I'm very glad that Sam is around to discuss this following his experience. Hope you're not too sore, pal.

[johnw]

Originally Posted by chezza

...all the models said he and Chris (the driver) should be dead...but unless I had dinner with a ghost last night they are most certainly alive...thus proving my above statement.

Or it might just prove that the models you are using are sub-optimal.

Whatever, delighted that they are both still around to argue with.

There are those of us who appear happy to accept that the HANS inventors are driven by altruism and provide us with a data and evidence which supports their invention.
I'm afraid that, to me, the two of you come across as cynics, suggesting that it's just a way of selling carbonfibre at a premium. Probably not your intention, but that's how it reads.

There will no doubt be further safety developments, but for now HANS offers me a chance to overcome the inadequacies of circuit barriers to decelerate vehicles and drivers heads, in a way which nothing else does.

I don't feel the same way about HANS use in rallying, as most impacts I've seen have been lateral, in which HANS offers little or no benefit. But head on into a tree, I'd rather be wearing one.

[chezza]

This wasn't me. This was students at cranfield uni looking at new and existing safety features/regulations. They all said Sam and Chris should be dead. As a marshal I know that things never happen the same way twice...you always have to expect the unexpected.

Please do not think that I am just agreeing with Sam on this because he and I are together. There are a lot of things I do not agree with him on, his response to flags being one of them.

I don't doubt HANS' ability in the head on type of accident that it is designed for...I'm just not so sure in other types.

[johnw]

Originally Posted by chezza

I don't doubt HANS' ability in the head on type of accident that it is designed for...I'm just not so sure in other types.

We can agree on that Chezza

Originally Posted by chezza

... This was students at cranfield uni looking at new and existing safety features/regulations. They all said Sam and Chris should be dead.

A salutory tale of the effects of Vodka and Red Bull

Originally Posted by chezza

... Please do not think that I am just agreeing with Sam on this because he and I are together. There are a lot of things I do not agree with him on......

Maybe you should try www.relate.org.uk then

[ss_collins]

hehe

[Tim Falce]

Originally Posted by chezza

I don't doubt HANS' ability in the head on type of accident that it is designed for...I'm just not so sure in other types.

Surely it is only designed for a head on impact or maybe even to stop the head going sideways as well. So all this talk about what happens if the seat moves or the floor buckles or the driver moves is irrelevant to the HANS. =In all of these scenarios the HANS will move with the driver and seat/belts as it is not fixed to the car.
You can never legislate for every accident or the what-ifs and any safety device can cause injury if the "Wrong" type of accident occurs.
On road cars air bags can cause a certain amount of injury but I would rather have slight burns or bruising caused by these rather than a caved in skull caused by a steering wheel or windscreen. seat belts can break collar bones but that is better than going through a windscreen, I have seen this happen and the body land in the road in front of me and that was a fairly low speed impact.
Like you say, you are not sure and no doubt the experts are not sure either. But for the type of injury they are supposed to prevent, from what I have read and seen they do a pretty good job.

[MGDavid]

>>>and the belts that restrain the driver and the HANS should be fastened to the cage.
===where did this come from - I've never seen belts attached to cages down at my end of motorsport (roadgoing saloons and sports cars).

[Al Weyman]

The cage is the strongest and most logical place to attach the belts, on this Penske/Banjo Mathews Camaro IROC race car I have in my garage the yanks have hung everything of the main tubular frame and that includes the seat and the belts even the gearbox mounts, this is the proper way to go if practical and far stronger tahn bolting to a flimsy floor pan.

[johnw]

Makes a lot of sense Al.
I have my shoulder belts mounted on the cage, but lap belts and crutch straps through the (suitably re-inforced) floor pan. The seat is mounted on the factory mounts which I rather assumed have been subjected to manufacturers crash testing. However, I think that I'll get the roll cage extended, to allow seat fitting to it.

[ss_collins]

MG david - belts to cage is quite common in clubbie saloons.

[Woolley]

That may have been a slightly wild assumption on my part. What I was trying to say is they're fastened to part of the car (often the cage), not to the seat, so if the seat breaks off you don't become an ejector seat assembly. Sorry for any confusion.

[dtype38]

Interesting point Wolley, but it would seem sensible to make sure that the seat is at least as well attached and kept in place as the ends of the safety harness.