Rope for advanced hitches

[John Paul Sanborn]

What color is that 5/16" Stable Braid? I use a 5/16" double braid that is coated and I believe it is made by Samson but I am not sure. The rope has been stored in my closet for about 7 years. It was red when I bought it new.

Tim, Samson SB is all colored with the coating, called Samthane or something. I think it is a polyurithane. I cant find the stat's but I beleive it does not degrade the MBS. I've seen clear, red, yellow, blue, orannge and I think green.

Just order a spool of clear from SeaMar.

I noticed on their site that Samsons old tenex ratings are in ABS and the new are MBS. So now my home spliced Tenex slings are good for only 500# SWL.

 

[Mahk]

Originally posted by TheTreeSpyder
the filler that doesn't really effect the strength, just keeps the line from flattening out (especially around curves) thereby maintaining strength by maintaining shape (very important to all ropes)

I read elsewhere that, although the core does add some strength, the main benefit of a rounded rope is for knot tying and handling characteristcs. A rope without a core will lose relatively less strength over a bend than a rope with a core because when the rope flattens the load is more evenly distributed between the fibers on the top and bottom of the bend.

Can anyone comment on this? Nick?


The corollary was that (for any type of rope) it is important to maintain a proper bend radius.


Mahk

 

[TheTreeSpyder]

i always kinda pictured the core needed for working around curves, rather than in a fixed knot; also so it didn't flatten out and stretch thin?

 

[Stumper]

Mahk is correct-flat is better for maintaining strength in a bend radius. The less distance from the neutral plane to the outer fibers the less the load is localized in those fibers.

Spydy, now that we have been talking about polyolefin cores etc. for a while it occurred to me----Specs from a few years ago showed the core fibers on Safety blue as nylon. Arborplex and some others use olefin but unless things changed recently. Safety blue has strong and heat resistent fibers (nylon weakens at 300 and melts at 440)

 

[NickfromWI]

Originally posted by Mahk
A rope without a core will lose relatively less strength over a bend than a rope with a core because when the rope flattens the load is more evenly distributed between the fibers on the top and bottom of the bend.
Mahk

Mahk-
That's true about the rope flattening. Remember that in (most) 16 strand arborist rope splices, there is no core in the eye, and in Brians favorite rope, Sta-Set X, the core is treated so that they flatten out into a ribbon, thus allowing more strands to share the load. It like when you bend a stick to break it. The ones at the top of the bend are the ones that break because they take more stress/stretch than the ones on the bottom/inside of the curve.
In most cases, it seems the curve would not be substantial to reduce rope strength, such as when the rope is running over a considerable branch or a pulley/block. but when you have the rope over a carabiner, you now have a 1:1 bend ratio...or even less. That when things get scary. Good thing I weigh 160 and my rope can hold a tiny bit more than that!!!

love
nick

ps- avoid the whole issue and use a thimble in your :Eye: splices!

 

[TheTreeSpyder]

Nice catch Stumpie! i double checked and my info was a lil off according to the web site! Actually it isn't listed in the center of the line, but the center of each cover strand! i liked the way the rope construction was explained to me before better, at least strength/heat wise!!

Still, no polyolefin is listed for the 3strand safety blue.

 

[Kneejerk Bombas]

Manufacturer's splices are the best.