friction saver

[RopeShield]

Hey trying to help. Might this be the answer you are looking for.
The knot strength loss is due to the bend in the rope.
A splice has no bend. That is why most splices are guaranteed at or near 100% rope strength.
But it is guaranteed the splice will lose strength due to wear and tear. Its about cycles to failure, right.

How that rope is attached/bent around/to something is another matter.

So we have Two Bending factors 1.You have the knot applied to the rope
2.you have what the knot/splice is attached to
and in this case a friction saver. Nothing wrong with a knot, it is just another bend in the rope to account for.
Thats how I make sense of it.
Hope this helps.

 

[treeyeti]

I wholeheartedly agree with your last statement Ropeshield. But with some trepidation I must add the the statement that I originally was interested/concerned/questioning was:

Rope continues to loose strength at the knot and especially when it is left permanently tied.
The longer a knot is left on the rings the more strength it continues to lose.
The short bends continues to stress the fibres.

I believe I've had all my questions in this matter answered and will not push the topic further.

Regards

 

[RopeShield]

The best info I can find.

On Rope by Smith and Padgett
" Rope fibre undergoes stress whenever they are bent or twisted.
The sharper the angle at which a rope is bent , the weaker it becomes at that point. At a tie, the rope's effeciency is reduced to approcimately 50 to 80 percent of its original strength."
"The larger the radius turns a rope makes, the more efficient the rope will remain."(retention of rope's straight pull strength)
Happy St. Patrick's Day