Woopie sling rope?

[fuda]

Hi Tuttle ?

i'll give it a blast if you send me some free bees LOL..............

[Ewan Murray]

The issue is not its strength its its heat resistance, theres a reason why its not used as the cover for doublebraid fricrion cord but used as its core for strength, I have seen amsteel blue spider leg melt when its slipped a small distance

 

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[Dog Tag]

Question answered Ewan. Ta. It has become a melting issue.. All rope is strong, but friction is always the issue..

[DrewB]

[ame=http://www.youtube.com/watch?v=WDIo-WZkSaM]Yale Cordage Ultrex vs. XTC Rope Static and Dynamic Test Demonstration - YouTube[/ame]

 

also an issue of using the correct material for the chosen job. does it matter if a rope ios rated to 11t if it cant take a shock load?

[nod]

Hey Folks

 

The debate is quite interesting in so much as; that which comes to light is that we are often lead into making decisions of what kit to use in what application by people who do not have either the practical experience or theoretical understanding of the work we do. Blindly pushing a situation to failure is not ideal, particularly if it arrives with surprise!

 

If we know that an application WILL generate enough heat to damage the kit it creates a choice; (i) use different kit, or; (ii) reduce forces to generate lower friction heat !

 

I understand what Tuttle is saying but if friction heat is generated then the intrinsic character of the fibres will only deal with that heat to a point. When that point is reached failure will occur to varying degrees until the rope melts through. You could insert a heat protective sleeve but the heat still has to go somewhere, & this could be through the sleeve & into the rope. Not an ideal solution.

 

I'm not sure what the Yale video is actually saying?

 

Both ropes were knotted, so as the load beds the knot in, friction will generate heat. If the melt point is low, of course the rope will melt & fail!!!? Would you use dyneema in this way? And if it were spliced would the result be the same?

 

There seem also to be a series of practical failings in the accident part of the video. I'm not convinced that the choice of ropes were the reason for events to unfold as they did & maybe the climber would still have been hanging upside down if his rope were dyneema.

 

Hearsay is a dangerous mentor. Buyer beware!

Edited August 14, 2012 by nod
Mispelyne!

[tuttle]

 

also an issue of using the correct material for the chosen job. does it matter if a rope ios rated to 11t if it cant take a shock load?

 

I don't that video is right from all perpectives, plus the break was on a knot on one of the examples.

[tuttle]

Hey Folks

 

The debate is quite interesting in so much as; that which comes to light is that we are often lead into making decisions of what kit to use in what application by people who do not have either the practical experience or theoretical understanding of the work we do. Blindly pushing a situation to failure is not ideal, particularly if it arrives with surprise!

 

If we know that an application WILL generate enough heat to damage the kit it creates a choice; (i) use different kit, or; (ii) reduce forces to generate lower friction heat !

 

I understand what Tuttle is saying but if friction heat is generated then the intrinsic character of the fibres will only deal with that heat to a point. When that point is reached failure will occur to varying degrees until the rope melts through. You could insert a heat protective sleeve but the heat still has to go somewhere, & this could be through the sleeve & into the rope. Not an ideal solution.

 

I'm not sure what the Yale video is actually saying?

 

Both ropes were knotted, so as the load beds the knot in, friction will generate heat. If the melt point is low, of course the rope will melt & fail!!!? Would you use dyneema in this way? And if it were spliced would the result be the same?

 

There seem also to be a series of practical failings in the accident part of the video. I'm not convinced that the choice of ropes were the reason for events to unfold as they did & maybe the climber would still have been hanging upside down if his rope were dyneema.

 

Hearsay is a dangerous mentor. Buyer beware!

 

Good points Nod, true about the video, I will never tie a knot in dyneema, that why all mine is spliced, the main factor in understanding dyneema (please don't take the DMM sling test as the be all) the fibres when manufactured are very long chains, and serves to transfer load more effectively to the polymer backbone by strengthening intermolecular interactions. (wiki!)

 

[ame=http://www.youtube.com/watch?v=7fUIZnNcLvI]Dyneema - YouTube[/ame]

[tuttle]

one for the heat/friction analysts....

 

[ame=http://www.youtube.com/watch?v=8CQDX4Tac1s&feature=related]Dyneema Body Armor Shot Testing - YouTube[/ame]

[DrewB]

I only posted the Yale vid as it shows a very high strength rope used in the wrong configuration breaks at a low load and a less strong rope, properly spliced takes a higher load. I think the irregularities were put there on purpose to prove a

Point. I presume.

[tuttle]

I only posted the Yale vid as it shows a very high strength rope used in the wrong configuration breaks at a low load and a less strong rope, properly spliced takes a higher load. I think the irregularities were put there on purpose to prove a

Point. I presume.

 

Good point, did not realise it was done for effect.