Rope Angles and Breaking Strength

[joe]

The rope angle chart looks like it's representing rigging sling tension to me.

Joe

 

[Norm_Hall]

The rope angle chart represents the load at the anchor (limb, sling, block).

 

[TheTreeSpyder]

i think for single leg tension of angled sling or line; same as/ same as.

The tension or loading would be inverse multiplier; or efficency lost(X Load). So; a sling would cut that tension in half; offering another equivalent angled leg of support. While a block(offering only single leg of support to load), would multiply that tension by another leg; per angle of both lines of pull on block; i think.

Angle Efficiency Calculator

 

[glens]

[ QUOTE ]
The rope angle chart represents the load at the anchor (limb, sling, block).

[/ QUOTE ]
If you're talking about the scanned catalog piece, yes, if you add the percentages on the left to the 100% present on the right.

But why the poppycock (will that word get through?) about the strength reduction?

 

[Shayne Picard]

The "strength reduction" is a sort of short hand for increase in forces. If there's a 100% increase in force, it's noted as a 50% loss of strength. I think writing it that way has utility.

But the problem, as I see it and as so many others have pointed out, is that those forces relate to the anchors, not to the rope passing through the block.

Joe says "The rope angle chart looks like it's representing rigging sling tension to me." While that is a possibility, it's too remote to warrant a diagram in the catalog.

As it's drawn, I see it as being misleading at best. Anyone who knows enough to understand why the diagram is incorrect will likely just read it, dismiss it, and move on; anyone who does not understand why the diagram is incorrect will likely read it, believe it to be accurate, and move on. That's dangerous in my opinion.