Ring Failure

Statistical quality assurance (batch testing) is appropriate for things like VCRs and Jim Beam. It's NOT appropriate for critical safety components.

It's standard practice to load a piece of hardware to half it's breaking strength as proof of no inclusions or defects. It does not affect the finished strength of the component.

100% testing of metal components should be mandatory on all strength rated life safety equipment. It would be nice on sewn gear too.

The Kong rings were in all likelyhood, batch tested. Had 100% of the rings been proof loaded, they would have never gone to market.
 
Family, sorry, but you're wrong.

Ever bought proof coil chain?

Testing a climbing product to say 200 percent of it's WLL should be absolutely harmless; remember we work with a 10:1 safety factor.

If putting 540# on a biner bends it, guess what... it was junk when it was made.
 
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Family, sorry, but you're wrong.

Ever bought proof coil chain?

Testing a climbing product to say 200 percent of it's WLL should be absolutely harmless; remember we work with a 10:1 safety factor.

If putting 540# on a biner bends it, guess what... it was junk when it was made.

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well.... at least i tried (ya'll did read my disclaimer right?)
grin.gif
 
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just for the record blinky, the rings were not tested and thats why there is a recall.....and the fact that two of them broke. Had none of them broke, who knows

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You don't know that. The supply chain is not at all clear on these rings. A lot more than two haven't broken.

SQA is a solid methodology, but it doesn't always apply.

Like I said before, Chouinard tested EVERY carabiner to half it's BREAKING strength. I've taken some big wingers on Chouinard biners and never even considered the biner might break because of a manufacturing defect.

Materials testing is old hat, proof loading metal products and subsequently selling them is normal.
 
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Family, sorry, but you're wrong.

Ever bought proof coil chain?

Testing a climbing product to say 200 percent of it's WLL should be absolutely harmless; remember we work with a 10:1 safety factor.

If putting 540# on a biner bends it, guess what... it was junk when it was made.

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Actually in this case he's right, Aluminum has a certian life cycle, this goes for anything made of aluminum. Like FT I'm just pulling numbers out of my head, but if an aluminum biner says its MBS is 5000 lbs and you load it to 500 lbs then you can only load it 10 times before it breaks. Thats called Cycle to Failure.

Please remember that these are not real numbers I just came up with them in my head.

BTW 200% of WLL of 10:1 is only 5:1 if you want to test it to half its stength it would be 2:1 2500 lbs, 540 lbs is only a 10:1 load.
 
There's a whole bunch of science you're missing, so I stand by my post... and my background in engineering.

Proper testing wouldn't load aluminum to past its elasticity point. What you're suggesting is absurd.

And again I say... EVERY piece of life-support gear should be INDIVIDUALLY proof tested.
 
The weakest point in any saddle/harness SHOULD meet the minimum standard for the country it is used in. Modifications to saddle by anyone, would let the manufacturer off the hook. However this puts the onus of the retailer of the ad-on parts in a tight spot.

This thread has/or will raise the awareness of critical issues of unrated gear! It is like putting the brakes of a Model "T" into an F1 race car, NOT a good idea.

A forum like this gets the word out. It also RAISES the bar at the manufacturing level. Check your gear, insist that your NEXT purchase is up to standard, AND let your fellow arborist (who MAY NOT have heard) that there ARE issues out there.

I believe the maufactures of the gear we use are schooled in what the have to do to maintain market share, I would hope they wouldn't care to profit by NOT standing behind their equipment!
 
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There's a whole bunch of science you're missing, so I stand by my post... and my background in engineering.

Proper testing wouldn't load aluminum to past its elasticity point. What you're suggesting is absurd.

And again I say... EVERY piece of life-support gear should be INDIVIDUALLY proof tested.

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If you have a backround in engineering then you know that they can proof test something made of aluminum, it passes that day, it gets used and abused and then unexpectedly it breaks, because it came to the end of it's cycles to failure.

I'm not saying these rings were tested in anyway, but I am saying that aluminum has a life and we need to think about that whenever loading aluminum hardware, during proof testing or work.
 
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Hi guys,

Just a quick post from all at Safety Technology who manufacture the TreeFlex harness.

In short the Alu rings used in TreeFlex are not from Kong and never have been - they are produced by CT (Climbing technology) who are now know as Aludesign. The rings are tested to 25kN for both the small rings in the leg risers and also the large ring on the bridge.

If you would like any specific questions answered, please contact me via email info@safetytechnology.co.uk

Many thanks,
Ben

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Thank you Ben for the informative response. You've addressed the load rating issue...now can you address the labeling issue with CT? Both name and load rating, please.

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Hi KyLimbwalker I have just received a spec sheet from CT showing the new markings for the rings. They will have the CT logo, Made in Italy, 25kN, and a 4 digit batch number.
These will be laser marked onto the ring.

If you need any other info, please do not hesitate to mail me or PM me during this week (the following 3 weeks I will be away from the office and may not get on the Buzz so often - work mails I have more access too when out and about)

Best regards
Ben
 
Cycles to failure on heat treated aluminum within the 10:1 range is so far off the scale it's not even worth considering. Testing to half breaking strength is not only acceptable, I don't want to buy any safety hardware that ISN'T proof loaded.

You're worrying about cycles to failure when impurities and heat treatments are MUCH larger issues. I'm still using 25 year old Chouinard D's on my 5:1. They get loaded to a grand frequently.

...and yes, I'm an engineer too... though I generally don't like admitting it.
 
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Can't we just throw out facts and knowledge and instead focus on the fact that someone said I was right?

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When Beranek says you're right about something, then we'll discuss it.
 
It makes me very happy to hear that the rings on the TF are
from a known source and that that source isn't one with that we should fear. Luckily I didn't have to cut any part of my harness to get the old rig off.

I'll put it back together before my next climb and it'll be good to go!

Ben- that's great news that CT is going to be etching all their rings now. When I got my first set of them a year or so ago I was reminded of my opnion that the only reason a company would put their name
on a piece of hardware is because they truly didn't want anyone to know who actually made it. I'm glad CT is no longer hiding!

Paolo- thanks for looking into this for us. I'll say it one more time- I love my tree flex.

love
nick
 
I have just received word that not only are the CT rings going to etched with strength rating (25 kN), company name, country of manufacture and batch number they will also be individually tested to 16 kN !!

CT has always sent the batch testing results with every order so now we will have complete and total accountability for every product they make. (the batch testing is performed by an independent testing company and tested to failure. Usual results for 28mm rings both Aluminum and Steel is over 40 kN)
 
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I have just received word that not only are the CT rings going to etched with strength rating (25 kN), company name, country of manufacture and batch number they will also be individually tested to 16 kN !!

CT has always sent the batch testing results with every order so now we will have complete and total accountability for every product they make. (the batch testing is performed by an independent testing company and tested to failure. Usual results for 28mm rings both Aluminum and Steel is over 40 kN)

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Hi Rich,

I think it will be Apave who will perform the tests. They are a notified body who perform EN and CE certifictaion.
 
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