The Working Load Limit (WLL) is a percentage of the breaking point of webbing or rope.
For instance, the ratchet straps that seem to be everywhere you look have a WLL that is one third of their rated breaking strength.
The Working Load Limit (WLL) is a percentage of the breaking point of webbing or rope.
For instance, the ratchet straps that seem to be everywhere you look have a WLL that is one third of their rated breaking strength.
Dave
"Loneliness is the poverty of self; solitude is the richness of self."~~~May Sarton
working load is a fraction of breaking strength. Common working loads are 1/10 or 1/15 of breaking. Weights and a tree limb should work. Drop a witness line next to the test line. Load the test line a bit to get the slack out and measure or mark the witness to test line. Load the test line up to several hundred pounds and see how much it stretched. If you llok around you can find elongation charts for different materials under load. I'd let things hang for a while to see if it kept stretching. The reason you want an witness line is the limb my sag. ;-)
Aaaahhhhh that is a good idea.
It's raining here pretty much forever, but when it stops I'll have to try it out.
Last edited by Morgoroth; 05-30-2012 at 07:56. Reason: wrong verb
Possibly originated here (see page 11)...http://www.caves.org/section/vertical/nhback/NH03.pdf
One old skool practice is to include a line or area of stitching deliberately weaker than the rope or strap. It is meant to fail first if the line or strap is heavily loaded and through heavy use. Quick inspection alerts you to the possibility that you should use a heavier rope or strap for a better safety margin, or that the line or strap is worn out.
That looks a lot like the PALS webbing I've seen used in military applications.
Mil-W-43668 Type III or Type IIIa nylon often has around 1000 lbs breaking strength, and it will definitely stretch. I have several rolls of the stuff and don't consider it useful for anything but attachment surfaces of 1000d cordura gear, and the occasional strap or handle.
I'm thinking your right. Or at least in the ball park.
It looks a lot like this: Clickyto me.
Once it stretches, will it go back to its original shape? or can I just stretch it and then it will stop?
What if I double it up?
This might be a silly question, but how bad is stretching?
I have 3 hammocks I'm building at once now so I'm trying to keep the cost down.
If it is nylon, they'd likely stretch to the point where you wake up on the ground...
Mule tape is a no stretch, cheap alternative...
"Do or do not, there is no try." -- Yoda
Thanks for that, well said. That chart and the caving articles / nylon highway articles get too much "air time" on this site and they are misinformation for our static loading uses and polyester webbing and poly thread. Those charts apply to dynamic loading of nylon webbing (stretchy) stitched with poly thread (not so stretchy).
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