Author Topic: Some sort of constrictor loop?  (Read 9810 times)

Mobius

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Re: Some sort of constrictor loop?
« Reply #15 on: June 20, 2015, 01:49:06 PM »
  that demonstrates to me that you either have an agenda or you really do not know what you are talking about. As time goes on I am getting the impression it is the latter, more than the former  :-\

  You are right ! If I do not buy your rubbish, I either have an agenda or I do not know what I am talking about !
 
 

LOL .... others can decide what is wheat and what is chaff  ;D

Dan_Lehman

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Re: Some sort of constrictor loop?
« Reply #16 on: June 20, 2015, 07:59:22 PM »
I have personal experience with a quality rope manufacturer (more than one) and have family members who actually did rope testing in that manufacturer's facility and know for a fact that there are guidelines followed and that testing is accepted worldwide. (Except here apparently.)
Acceptance of mediocrity doesn't elevate it.
Of test reports that I've seen from various places,
there is a lot left to want :

1. clear specification of the tested item (the common example
 I keep pointing to is the fig.8 eyeknot, where structure
 isn't shown but just presumed known(?!).

2. details of where the knots break (some marking method
seems like the best method to determine/guesstimate this).

3. testing in different conditions of loading (as Inkanyezi once
remarked, the standard straight-gradual-pull loading is often
least likely to occur in practice!)

Instead, we see little more than hints of repeated, vague testing.
--maybe %-strength figures are based on ratings, maybe on
actual testing of the line.  (Maybe a later edition of a book will
contradict earlier-edition-published values !  --think, CMC Rope
Rescue (4th vs. 3rd editions).)

Dave Richards did some testing in a trio of common kernmantle
nylon ropes --12.5mm low-elongation ("static"), 10.5mm dynamic,
and 7mm low-elongation ("accessory cord")--, and then his report,
though suffering my listed faults, disappeared from the caving-org.'s
hosting just because of a confusion of tables, wrongly misunderstood
as some profound confusion of results (vs. an A vice B swap)!
.:. All of this points to a lack of care & attention to knotting, IMO.
(And yet, life goes on ... .)


--dl*
====

SS369

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Re: Some sort of constrictor loop?
« Reply #17 on: June 20, 2015, 08:46:35 PM »
Hi Dan.

Your points have some merit, but what you quoted of mine was speaking of "rope".
So, stay with that statement if you will.

Yes, there are a few manufacturers who have tested knots, etc., and show all in their videos for any viewer to analyze.

I don't think it is realistic to expect these manufacturers to perform Their tests to IGKT  member's criteria unless asked. Or to scientific standards as demanded here.

So, unless someone knows someone with an acceptable load cell facility, supplies the $'s or knotted materials, and then the agreed upon test procedure, the wind whistling will continue.

Back to "Some sort of constrictor loop?" please.

SS
« Last Edit: June 20, 2015, 09:01:11 PM by SS369 »

Mike

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Re: Some sort of constrictor loop?
« Reply #18 on: June 23, 2015, 03:39:02 AM »
SS369, What part of the world you live in and what Manufacture do you know?  I happen to live pretty close to a big rope manufacture myself..  We might be neighbors... :)

SS369

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Re: Some sort of constrictor loop?
« Reply #19 on: June 23, 2015, 02:10:31 PM »
Replied via PM.

SS

 

anything