Wings container - distorted (ovalled) hip rings

[pchapman 279]

A jumper at my DZ discovered that the hip rings on his Wings container were starting to get quite distorted, bent into an oval shape.

The rings have the Wichard stamp and are also marked 316L (which sounds like the grade of steel). I've seen the same markings on other Wings hip rings. I think there's no part number to distinguish it from other rings.

Since the bend had become quite sharp on one ring, the rig was taken out of service and is being sent to the manufacturer.

It's a rig from 2002, and both the original and current owner are in the 230-240 lb range.

Nobody noticed the problem -- neither the owners, other jumpers, or riggers including myself -- because the bending process was so slow and gradual over the years. Only now is there a sharp bend in one ring, and the two rings are clearly different.

Given all the variations there are in hip ring joint constructions, everyone just thought that that production run or model year had been built with oval forged rings. It's easy to see when something that's supposed to be round is oval, but it's harder to notice that something oval is a little more oval that it was 6 months ago. This is the kind of error that can slip through an inspection, where the manufacturer's intent is not known. That's a whole topic in itself.

[BKR 0]

There are 2 kinds of SS used for such ring
316 L and 630 (US AISI Norm)
The strongest is 630 normaly used (PdF) for such hip ring on MLW. 316L is normaly OK, it breaks at 4000/4500 kg. But, as you maybe know such SS is heat forged and everything can happened. Hopefully the 316L is more flexible than 630, so you can be advised before it breaks.

Jérôme Bunker
Basik Air Concept
www.basik.fr
http://www.facebook.com/pages/Le-Luc-France/BASIK-AIR-CONCEPT/172133350468

[riggerrob 643]

This reminds me of a similar problem encountered by Rigging Innovations during the early 1990s.
When R.I. introduced the Flexon, it was the first sport harness to incorporate hip rings. The first Flexons used stainless steel hip rings, the same size as RW-0. RW-0 is a simple ring, that preceded the slotted harness rings (RW-1, RW-7, RW-8, RW-9, RW-10, etc.).
Remember that this was just after Parachutes de France introduced the Blue Track and PD introduced the Sabre with several new technologies (ZP fabric, zero-stretch suspension lines, wing-loadings exceeding 1:1, etc.). It took skydivers a few years to learn how to pack Sabres so they would open softly.
Meanwhile, several skydivers suffered very fast openings that shredded Sabres, broke neck bones, etc.
A few of the victims returned their Flexons to R.I. to have bent hip rings replaced. R.I.'s short term solution was to completely replace harnesses that suffered bent hip rings.
R.I.'s interim solution was to switch new production to cadmium-plated RW-0 rings which were slightly stronger.
R.I.'s long term solution was to switch Voodoo production to smaller RW-8 (slotted harness rings). Now R.I. uses "flattened" stainless steel RW-8 rings on most of their harnesses.

[councilman24 37]

Somewhere here I posted about a customer of mine having distorted rings. He'd sent the rig in before I had a chance to see what markings were on the rings. Sunrise said they had seen it before and replaced the entire harness on the rig. AFAIK they've never issued a service bulletin or any notification of this problem. My customers Wings was fairly early 2002 and shortly later Sunrise changed the rings they were using. The few other Wings in the area are later DOM and have different rings.

I'm old for my age.
Terry Urban
D-8631
FAA DPRE

[pchapman 279]

Quote

Somewhere here I posted about a customer of mine having distorted rings.

Interesting! (I didn't see that post when searching before making my post, and still can't find it.)

The ring stamps were the same on the bent 2002 rig as and on a similar 2001 rig that was also jumped by heavy guys, but which has apparently undistorted rings. I haven't yet compared to newer rigs.

I'll post again down the road whenever I find out what the factory tells the owner.

[Calvin19 0]

so, not only are wings containers ugly, but they use maluable metal for VITAL attatchments. great.

-SPACE-

[sundevil777 102]

You wouldn't want a brittle metal. You just want it to be strong enough.

Fortunately, ductility of metals often works in their favor when their strength is exceeded. The ring distorts until the stress is lowered because of the different shape. Obviously you don't want it to distort, but it really doesn't mean it was close to breaking.

People are sick and tired of being told that ordinary and decent people are fed up in this country with being sick and tired. I’m certainly not, and I’m sick and tired of being told that I am

[Vectracide 0]

Quote

so, not only are wings containers ugly, but they use maluable metal for VITAL attatchments. great.

Ya know, if your going to be rude and bash a leading container manufacturer, you might want to use spell checker next time, Einstein.

Maluable is malleable

Attatchments is attachments

Have a nice day!

------------------------------

Controlled and Deliberate.....

[scotts 0]

Quote

Quote

Somewhere here I posted about a customer of mine having distorted rings.

Interesting! (I didn't see that post when searching before making my post, and still can't find it.)



It was posted on the PIA rigging forum.

• Quote

[billvon 3,111]

> so, not only are wings containers ugly, but they use maluable metal for VITAL attatchments.

Happens on many rigs. Bill Beaver had a slammer of an opening years ago and bent the hip rings on his Talon (I believe.) In general it's better for harness rings to bend rather than break.

[slotperfect 7]

Everyone is entitled to their opinion here, as long as it fits the Forum Rules. Calvin19's opinion in this thread, although not terribly tactful, fits the rules.

Unless you have content to contribute to the subject of the thread, please confine your pointed spelling corrections to PMs.

The one liner reply, which will only lead to more thread drift, has been removed.

Arrive Safely

John

[jumpwally 0]

What if you used two rings side by side together? would that give you enough strength not to distort? Not much bulk,not much wieght, little cost....Just curious.

smile, be nice, enjoy life
FB # - 1083

[RMURRAY 1]

I'll take an non articulated harness everytime - no need for hip rings with a racer.

rm

[masterrig 1]

Quote

I'll take an non articulated harness everytime - no need for hip rings with a racer.

rm

_________________________________

But... but... those aren't cool! I'm with you. I much prefer non-articulated harnesses.


Chuck

[billvon 3,111]

> What if you used two rings side by side together? would that give you
>enough strength not to distort? Not much bulk,not much wieght, little
>cost....Just curious.

Perhaps. But keep in mind that if the rings yield a bit, that may prevent the MLW from coming apart - and may reduce the shock loading to survivable levels. Doubling up hardware will also make the hip ring junction less comfortable and more protruding, and that will accelerate wear for some jumpers (like cameramen.) The two rings may create a new pinch area that can prematurely wear harness webbing and jumpsuits. They may even make the MLW itself weaker by changing the angle of loading the sewn area sees.

If properly treated rings yield a bit under extremely heavy (i.e. unusual) loads, but do not fail - that tells me they are about the right strength/temper for use in that application.

[AggieDave 6]

Quote

It's a rig from 2002, and both the original and current owner are in the 230-240 lb range.

I wonder what other specific factors are involved. I have a Wings from 2002 and weigh 250lbs without gear. I've also had some slammer openings, but I haven't had any distortion in my hip rings. I don't doubt that they have happened, although its good to see that the rings took the load, distorted, but didn't break or send the load to another part of the harness that may not have held up to the load.

--"When I die, may I be surrounded by scattered chrome and burning gasoline."

[faulknerwn 38]

I'll join the non-hip majority! I love my non-articulated harnesses - I like my rig snug!


W

[gjhdiver 0]

First of all, this is an old problem that's been corrected for some years now, and it wasn't confined to the Wings alone, as others have noted.

All of the hardware used in construction of all harnesses is sourced from outside manufacturers, and as such, all manufacturers are dependent on those source producers for quality assurance of materials. There's no real way to test the tensile strength of most of these parts without destroying them.

What's nice to see is that the rings will deform under unusual loads, whilst the webbing itself is undamaged. At Wings though, any reported deformation of hardware will result in a complete rebuild and retrofit of the harness.

[riggermick 7]

Quote

This reminds me of a similar problem encountered by Rigging Innovations during the early 1990s.
When R.I. introduced the Flexon, it was the first sport harness to incorporate hip rings. The first Flexons used stainless steel hip rings, the same size as RW-0. RW-0 is a simple ring, that preceded the slotted harness rings (RW-1, RW-7, RW-8, RW-9, RW-10, etc.).
Remember that this was just after Parachutes de France introduced the Blue Track and PD introduced the Sabre with several new technologies (ZP fabric, zero-stretch suspension lines, wing-loadings exceeding 1:1, etc.). It took skydivers a few years to learn how to pack Sabres so they would open softly.
Meanwhile, several skydivers suffered very fast openings that shredded Sabres, broke neck bones, etc.
A few of the victims returned their Flexons to R.I. to have bent hip rings replaced. R.I.'s short term solution was to completely replace harnesses that suffered bent hip rings.
R.I.'s interim solution was to switch new production to cadmium-plated RW-0 rings which were slightly stronger.
R.I.'s long term solution was to switch Voodoo production to smaller RW-8 (slotted harness rings). Now R.I. uses "flattened" stainless steel RW-8 rings on most of their harnesses.

Hey Rob,

Remember the 1982 RW 1 soft ring issue? I cut many rings off of harnesses that failed the pull test. RW 2 seperable rings came into vouge, spooky huh? BTW they were all US Forgecraft products.

Mick.

[JerryBaumchen 1,466]

Hi Mick,

Quote

1982 RW 1 soft ring . . . were all US Forgecraft products

At the '91 or '93 Symposium, three guys from Forgecraft gave a seminar on the making of parachute hardware.

I asked them about the ductility of the material. After some substantial back and forth, they still did not have a clue what I was talking about. They simply did not know.

And after watching their slide show on their testing apparatus it was not any surprise to me that the soft rings made it through their system. Their testing fixtures simply did not reflect in-use loading conditions.

In my professional opinion, those guys should not have been in the metal forming business. And I have about 30 yrs working with companies in the metal forming business, witnessing thousands of tests.

Just my thoughts,

Jerry Baumchen
Mechanical Engineer

PS) I still have a couple of those old removable 3-rings laying around. Every now and then I come up with a use for them.