Breaking strength ratings, misc. life support hardware

Burnham

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Ok, I have some questions that keep bugging me. And some of these subjects keep rearing their ugly heads during my discussions with my peers on the USFS tech. advisory group. Not interested in safety police action here. Just want to hear opinions of where we stand meeting recommended standards.

As I interpret ANSI Z133.1, all life support hardware has to meet or exceed breaking strength ratings of 5,000 lbs. or 23 kN. Does anyone see a different reading?

If that's the case, how are we to view use of several rope grabs that many of us use daily that do not pass this standard? Case in point: the Petzl microcender/micrograb is rated by Petzl with a breaking strength of 3,500 lbs.

I am fully aware that this units slips on the rope at far lower loading than that BS rating, so it's not a question of safety I ask about, more one of could OSHA cite an employer for it's use?

Plenty of other examples: to my knowlege, no handled ascender meets the 5,000 lb. BS rating either. Again, they will destroy the rope if dynamically loaded at far less than 5,000 lbs. so the issue of breakage is rather moot as a practical matter, but are we "violating" Z133.1 when we use them?
 
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I am no expert but I was under the impression that those types of items could not be used as primary life support. They must be backed up. When ascending single line with a handled ascender and Pantin, my friction hitch is tied and rides along on the rope. Therefore my backup is capable of meeting the 5000 lb requirement so I'm golden. I really don't have any experience with some of the other ascender/ descender type rope grabs such as the ID and others so I can't speak for those.
 
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Good point, Brian...and here's a rub. I am liking the heck out of backing up my double handle, two rope Kong ascender with the Micrograb. Doesn't appear to be a compliant arrangement, even though I KNOW it's safe.
 
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How about useing the Micrograb as a lanyard adjuster, and the Positioner...neither meets the 5,000 lb. standard.

I'll bet the Trango Cinch doesn't either, though I don't know.
 
But if you ever actually NEED that backup, the same forces that will cause the handled ascender to fail will also overload the microscender. A short VT hitch tied with 5/16" or 3/8" cord will more than meet the 5000 lb requirement and will not shred the rope if you actually have an overload situation.
 
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I'll cede your point in that application and situation, Brian. But there are several other failure scenarios for ascenders that have nothing to do with dynamic loads.

How about the lanyard adjusters?
 
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Also, my main question doesn't revolve around whether these items work, or are safe...it's a question of is my interpretation of the Z correct, and are they therefore non-compliant.

Look in any arbo catalog...there are quite a few products sold in applications that seem to me to not meet the BS standard. What's going on?
 
Brendon- The hitch cord is attached at both ends. This essentially makes a 'basket' configuration which pretty much doubles your WLL. If it is 3000 lb cord then you have 3000 lbs on one end and 3000 lbs on the other end.
 
Also, my main question doesn't revolve around whether these items work, or are safe...it's a question of is my interpretation of the Z correct, and are they therefore non-compliant.

Look in any arbo catalog...there are quite a few products sold in applications that seem to me to not meet the BS standard. What's going on?

My guess would be that nobody really cares about the ansi reg. Obviously you NEED to care due to your position but the average Joe just wants something that works. I dont know anybody who has EVER been cited by osha for non compliant safety gear. Heck most co.s dont even have functional chain breaks!!!!
 
It is a problem Burnham. Alot of the equipment meets European CE standard of 22kn, but does not meet the US standard of 23 kn or 5000 lbs., but is yet still sold and marketed here. Personally the 22kn is good enough for me. I would like to see the standard revised to 22kn.
Regarding ascenders, there is no ascender on the market (that Im aware of) that even comes close to the US standard. The petzl acensions have a rating of 8kn I think, but yet are CE approved. The CMI acsenders, dont even have the CE approval. The petzl ID=CE approved, the grigri= CE approved, Yates rocker= rated to 22kn, rock exotica dualcender=no rating, but slips on the rope at 4.5 kn, so on and so on.

Im just thumbing thru the Sherrill catalog, yes, much of the equipment doesnt meet the standard. Im a little disappointed in the lack of published strength ratings altogether, despite whether they meet standards or not.

Are we violating the standard using such tools? I would venture to say yes, unless they are used in a system with redundancies built in which do meet the standard.

It certainly is not clear, there is alot of vagueness.
 
The minimum strength for rope is 5400 lbs tensile strength. This applies to climbing lines, hitch cords etc. The tensile strength rating is the standard minimum. While I agree about a hitch cord splitting the load, my interpretation of the standard is that a rope or cordage with less than a 5400 lb tensile strength DOES NOT meet the standard, used singled or doubled.
 
My guess would be that nobody really cares about the ansi reg. Obviously you NEED to care due to your position but the average Joe just wants something that works. I dont know anybody who has EVER been cited by osha for non compliant safety gear. Heck most co.s dont even have functional chain breaks!!!!


I dont agree with that.
 
Safety is number one always. We all know that. But in the hands of bureaucracies setting the standards for all,,, they so often leave the exceptions to the rules out. And doing so just dummies down the craft and leaves room for misunderstanding and further accidents in itself.

In my opinion, any safety institution that writes a rule that states you should not do a certain thing should also back it up with all the reasons why you shouldn't, and then cite the special circumstances where it may be applicable to do so.

Institutions, bureaucracies, and the like,, miss the key understandings to what is most important to safety when they write rules in black and white and leave exceptions out.
 
If that reg was different...it would open doors...

I guess my harness, slings and shoelaces are weak.....I give up:cry:
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I think PCTree is right. Most guys/businesses just don't care as much about the regs because they are more concerned about their lives. They want gear that works, and if it also meets safety standards then so much the better, but if it doesn't...

Also the ANSI standards are not (yet) mandatory. And OSHA, which can issue non-compliance fines, doesn't seem to be fully aware of what it is that we exactly do for a living or else would probably know most of us aren't loggers.
 
But if you ever actually NEED that backup, the same forces that will cause the handled ascender to fail will also overload the microscender. A short VT hitch tied with 5/16" or 3/8" cord will more than meet the 5000 lb requirement and will not shred the rope if you actually have an overload situation.

Not if its tied with a knot in any high modulus line. One has to subtract 50% strength loss when knots are tied. The only reason its cool in drt is cause the load is split with the two legs of lifeline.
 
I think somebody miscalculated ........

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