Harnessing

General Regulations on how a NEHA hillclimb should function, how the series works, etc.

Harnessing

Postby SevenhundredS » Thu May 09, 2013 2:17 pm

I've a new 5 point harness on the drivers side but I wasn't sure where to go with the shoulder attachment. The previous straps (out of date) were on the cross bar that is welded behind the cage; passed through then welded with a secondary strap going to the back deck.

In a sense, I suppose I've created a Y Harness, which is not allowed, but not really. If I can stick some pictures up you'll see I've added a lap belt to reach the rear deck but this means the new harness is no longer integrated with the cross bar. As an added precaution I put cotter pins through the bolts and put one should over the diagonal bar. This could easily be moved.

Thoughts, suggestions.
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Re: Harnessing

Postby sachilles » Thu May 09, 2013 3:06 pm

Walter will be the guy best suited to give you an answer. If you can get a picture from your rear window in towards the seat back in addition to the pictures you already posted, that might give a better view.

edit:
Nevermind, I see you have the view I suggest, just didn't realize it. :oops:
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Re: Harnessing

Postby walterclark » Thu May 09, 2013 6:49 pm

Its a little hard to see everything but it looks like you have 2 shoulder straps bolted together then to a single web that goes back and anchors. Is that right?

We dont allow Y harnesses because of the loading and dependence on a single strap and anchor. Don is the final decision maker on these things but I would bet he would want to see the drivers side changed before you run, even if its something temporary - like separating the harness straps to the anchor points - i.e. use a second strap (like your single) to the rear so the harness straps each attach to the vehicle at separate points and not each other, and locate those points either side on the one there now..

The best bet with that setup (again it is a little hard to see everything) is to weld in a U shaped bar at about shoulder height or very slightly lower, to the uprights on your main hoop that runs horizontal behind both seats (since a straight bar probably would not be able to do that, a U would give you some setback). Then you can weld 4 tabs to accept the end fittings of your harness with suitable bolts and nuts.
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Re: Harnessing

Postby SevenhundredS » Thu May 09, 2013 9:07 pm

walterclark wrote:Its a little hard to see everything but it looks like you have 2 shoulder straps bolted together then to a single web that goes back and anchors. Is that right?
We dont allow Y harnesses because of the loading and dependence on a single strap and anchor.


That is a correct description except the two straps are built together, not bolted together.
Image
The bolt comes after. As in, this is a brand new, supposedly, SFI 16.1 approved "V" belt. Which begs the question, what's the difference between a V and a Y belt if they both rely on one anchor for two straps.

As I back up, of sorts, I set this up so the two straps are on either side of the diagonal of the roll cage. Should the anchor fail, the crotch off the V would catch on that only a couple inches further, with less energy. Personally, I think I might prefer that sort of even failure over having one shoulder fly free while the other is still held.

I don't have a welder at this point.

Please note that do I appreciate all this help.
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Re: Harnessing

Postby sachilles » Thu May 09, 2013 9:21 pm

Who makes the harness?
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Re: Harnessing

Postby Rabbit Farmer » Thu May 09, 2013 9:52 pm

V-style.... (SFI 16.1)

Image

Y-style.... Looks like the difference between V and Y is the shoulder straps on the Y are sewn into the continuation of the strap as opposed to terminating like the V.
Image

Heck... there is even a U....

Image
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Re: Harnessing

Postby Rabbit Farmer » Thu May 09, 2013 9:53 pm

So... this begs the question... Y-belts aren't allowed. Doesn't say anything about V. I did not go back to the rules to see if there were rules about how each shoulder strap must terminate, I just made a general observation regarding the Y not being allowed.

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Re: Harnessing

Postby walterclark » Thu May 09, 2013 9:59 pm

It says 5-6 and 7 point harnesses are mandatory for all cars with a cage. Y harnesses are not permitted. The V and Y are a version of a 4 point harness.

I will talk with Don about this. I have a couple ideas but want to run them by him before I suggest anything.
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Re: Harnessing

Postby Rabbit Farmer » Thu May 09, 2013 10:36 pm

Is the U style considered no points (like a Mobius strip) or one?
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Re: Harnessing

Postby walterclark » Fri May 10, 2013 7:32 am

I got the definition wrong...shame on me. I should have read a little more about belt styles we dont see often (or permit) before I commented.

The 5, 6, 7 point definition is derived from the number of straps coming into the buckle system, not the number of anchor points. Usually they are the same, but not in the case of the Y, V, U designs, and in some cases the dual crotch straps in 6 and 7 point share the lap strap mount points (separate bolt-ins on a common anchor bolt or eye). 4-point harnesses are lap and shoulder belts without a crotch belt.

I still need to speak with Don.

Mike. So I have a more complete picture...The single strap from the shoulder harness bolt end to your rear deck isnt part of the Dragonslayer harness set. What exactly is it? It sort of looks like parts from another harness. Does it have an in-date (<3 years from date of manufacture) SFI label? And I curious, why did you go with the V rather than the separate shoulder straps?
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