Broken aluminum ring

Tobe_Sherrill

New member
Friends,

I was just informed that an aluminum ring that we splice into an adjustable friction saver has broken. No one was hurt. Without the broken parts in hand we have yet to conclude whether the ring was abused, defective or of substandard materials, but the worst is to be expected.

All we do know is that the ring WAS NOT MADE or supplied by Buckingham, Petzl or DMM. From a photo that I've seen, the ring appears to match what we have in stock from Kong. If, in the coming weeks it proves out that the ring was defective or of substandard materials there will most likely be a recall issued by the manufacturer.

The ring mentioned is most commonly spliced into our adjustable friction saver (code 33002, 32152) but are also sold alone in two sizes, small and large (26585, 26584). The variety that broke is polished aluminum (silver in color) and without any logo or other markings. This ring also has a faint "casting seam" around the outside edge. http://www.sherrilltree.com/Professional-Gear/Rings/Large-Alum-Ring-828

PLEASE INSPECT life support tools periodically for signs of damage or defect. If you drop (purposefully or by mistake) hardware from height, consider disposing of it permanently as is common in many other life support professions. Hairline cracks in metal can be difficult to detect with the naked eye.

Given the circumstances, and even without a recall, SherrillTree will voluntarily replace any SherrillTree-supplied product having the above-described ring with a more clearly marked and certified variation as soon as they come available. Please mail your polished aluminum ring or ring-attached splice to;

Ring replacement
SherrillTree
200 Seneca Rd.
Greensboro, NC 27406
(please include your return address and telephone number inside the package)

Further details to be posted (within this thread) as soon as available. We sincerely regret any inconvenience or anxiety this is certain to cause.

Tobe Sherrill
 
thanks! i just heard this happened through the grapevine - and I'm glad Sherrill is offering the replacement. I used my adjustable friction saver yesterday in a rec climb and thought about the rings a few times...

IMG_8599.jpg
 
Latest --

We’ve just completed a test to failure of nine small Kong rings and none broke below 6,800 pounds.

Since the broken ring in this incident lacks identification or a rating stamp we are inclined to direct our attention there. In inventory we discovered one Kong box of small rings with no markings (brand or ratings) as we’ve insisted upon from Kong on life safety products. This box was among other Kong boxes of rings that have the marks. Kong is looking into why they shipped unmarked rings (only small as far as we can tell).

NOTE; Kong is not the only manufacturer of aluminum rings for life safety that do not have a printed stamp of brand and strength.

Half of the failed ring has arrived here from the principal in the incident and will be forwarded to an independent lab, followed by the manufacturer in Italy for examination(s).

In the mean time we have pulled from inventory any unmarked rings (including spliced goods containing such) and await the manufacturers response.

Unless the outcome points to lack of concern for quality or outsourcing to an unmonitored manufacturing facility then I’ll retain great respect and trust in Kong products. This company is well respected around the world for a high standard of safety in climbing, paragliding and rescue disciplines, to name but a few. From all that I know and from years of working with their people I will continue to trust my own life to their products.

More as it’s received.

Tobe
 
Does anyone know what was going on when the rings broke? Was it abused previously? Wasn't it a Bartlett trainer guy who had them break - just curious to know the before history of the rings...
 
[ QUOTE ]
Does anyone know what was going on when the rings broke? Was it abused previously? Wasn't it a Bartlett trainer guy who had them break - just curious to know the before history of the rings...

[/ QUOTE ]

Exactly.
 
Dear friends,

Attached to this post is official notice from SherrillTree recalling an aluminum ring sold for use in life support activities.

Certified notice by US mail along with return packaging is being assembled for distribution in the coming few days.

The rings that Sherrill, Inc. distributes have always been strictly sourced from KONG Bonaiti of Italy based on a high level of confidence in products forged by the manufacturer. It appears that the rings in question were not and, most importantly, did not receive individual testing.

We strongly recommend climbers using polished aluminum rings not sourced from SherrillTree (or Vermeer dealers) and not having strength ratings inscribed, to contact their supplier and push for replacement. There’s great likelyhood that the manufacturer of the ring in question (not Kong) exports directly or indirectly to several other arborist suppliers.

(Known arborist manufacturers NOT distributing this ring include Petzl, Buckingham and Komet.)

With best regards,

Tobe Sherrill
 

Attachments

Tobe,

Do you know how the rings were being used? It is difficult to imagine even poor quality rings breaking from a climber's weight - not that'd you'd want to climb on a poor quality ring, I'm not saying that, but aren't most rings rated at 5000 lbs? The rings are about 7/16" in diameter aren't they? Seems like it'd have to be a really shabby ring to break at a climber's weight???

I machined a about a 4 inch (od) ring out of plain ol 1/2" 6061 Al plate, and a mechanics class at school tested it on our tensile machine as a project. The thing held 10,000 lbs., deformed into a oval with parallel sides and still didn't break.

So, this is puzzling to me.
 
It was being used in a demonstration/training on a college campus from what I recall about the story. The ring was not abused and was in good condition. The ring broke when the instructor was just off the ground. It was in a friction saver. Not sure if it was spiced by Sherill.
 
[ QUOTE ]
It was being used in a demonstration/training on a college campus from what I recall about the story. The ring was not abused and was in good condition. The ring broke when the instructor was just off the ground. It was in a friction saver. Not sure if it was spiced by Sherill.

[/ QUOTE ]
This is ironic, that is exactly what I was doing with the ring I machined. Actually, I machined two rings, a large and a small and demo'd how they are used. I demo'd a false crotch just like this instructor, to a statics class by climbing a tree just outside our engineering building.

This breakage is really bizarre, not saying it didn't happen, it did, it's just unnerving to think that an aluminum ring could break with no more than body weight.

I am confident that this will prove to be a very bad, very faulty manufacturing process.
 
[ QUOTE ]
It was being used in a demonstration/training on a college campus from what I recall about the story. The ring was not abused and was in good condition. The ring broke when the instructor was just off the ground. It was in a friction saver. Not sure if it was spiced by Sherill.

[/ QUOTE ]

Son of a Bi...! It broke under body weight? Was it new? Seems like a manufacturing defect would go ahead and fail pretty quick. If it wasn't new I would suspect damage of some sort. It's hard to imagine one of those breaking under a light load like that without showing some kind of warning signs.
 
Blinky,

Exactly what I'm thinking. I haven't tested this, but I'd think you could take a piece of 7/16" al rod and bend it into a ring shape and leave the ends unjoined and it would readily support body weight. 'Course as I said, I haven't tried that and there's not much point in it or I would try it, and may anyway - this is just really bizzare.
 
I'll get as many details as I can the next time our division safety coordinator stops in. I just asked a few simple questions but I'll ask more in depth.
 

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