Rope Splice Question

[Gauge]

I am heavily considering grabbing the new Arbormaster rope in the hawkeye color (they finally made a lime green one ) and I think I want a tight spliced eye on one end. If I have read correctly the spliced eye (if done correctly) is stronger than any termination type knot. Is this correct?

 

[Peter]

Yes.

 

[ruel]

Way stronger! What makes you want to go with a 16 strand climbing line?

 

[Gauge]

Way stronger! What makes you want to go with a 16 strand climbing line?

We are using Arbormaster Blue streak ropes at work and they seem to be really good ropes. We all run DRT with a split tail and a micro pulley and they work great there too. I really like the feel of the 1/2 rope as well and most 24 strands are 7/16 save the Vortex lines. If you can change my mind I will take a look at 24 strands but it will be hard to do.

 

[Raj]

Once you go SRT you'll change your own mind.

All though I love doing the 16 strand splices, they are nice and even. I like the 16 strands for long lanyards, tight eye, rubber tubing, biners stay firm and don't flop.

 

[RopeArmour]

Triple fisherman beats a splice. Read that recently but can't remember where. Forcing the rope open/ throat ing over bending snf and comprrssing

 

[Gauge]

Once you go SRT you'll change your own mind.

All though I love doing the 16 strand splices, they are nice and even. I like the 16 strands for long lanyards, tight eye, rubber tubing, biners stay firm and don't flop.

Isn't 2 ropes better than 1? Safety wise

 

[Boomslang]

Isn't 2 ropes better than 1? Safety wise

Nope. Just twice as much to worry about. You cut either side you're gonna have a bad day all the same.

 

[NickfromWI]

Triple fisherman beats a splice. Read that recently but can't remember where. Forcing the rope open/ throat ing over bending snf and comprrssing

There's no way this is true.



love
nick

 

[Knot Rigger]

There's no way this is true.

There is one thing that a triple fisherman's knot can do better than a splice: absorb energy.

In that respect, in the right rope under shock loading, a knot can be stronger than a splice.

here is a british rope's access study: http://www.hse.gov.uk/research/crr_pdf/2001/crr01364.pdf
they test, among other things, various shock loads on different types of short lanyards ("cow's tails" in rope access language) and a barrel knot (aka: double fisherman's noose) in dynamic line outperformed the petzl jane, and others, in limiting peak force.

But generally no, I agree with Nick, a splice is usually much stronger than any knot.

 

[NickfromWI]

That pdf is 166 pages long. Can you direct us to a specific 1-2 pages?

Strength has nothing to do with energy absorption. Two totally different things


love
nick

 

[Knot Rigger]

That pdf is 166 pages long. Can you direct us to a specific 1-2 pages?

Strength has nothing to do with energy absorption. Two totally different things

section 7, page 79

Strength and energy absorption are related, when you consider shock loading. If a knot can help absorb the force of a shock load, this raises the overall strength of the system. It's a very limited circumstance of when a knot could be preferable to a splice, but it's interesting to me. A "stronger" splice might snap under shock loading, but a "weaker" knot might constrict, limit the load, and survive. Which system is stronger?

In the rope access testing document, dynamic climbing rope with knots and sewn terminations was compared (among other things) the knotted samples had a peak load of 55 to 65% of the sewn terminations. Additionally, as a practical matter, the knotted cows tails we're easy to tell they were shock loaded and should be retired. The sewn, "jane" cow's tails we're impossible to visually inspect to determine they had been shock loaded.

 

[chris_girard]

Very interesting to consider rope in that way.

 

[NickfromWI]

I'll go back to what I originally said. It isn't true that the scaffold knot is stronger than the spliced or sewn termination. This is from page 80:

• The overhand knots gave consistent impacts of 7.0 kN to 7.2 kN, while the figure-of-eight results were slightly wider, at 6.7 kN to 7.6 kN
• The Barrel knots performed extremely well, delivering consistently low impact forces of 6.3 kN to 6.4 kN


They aren't measuring strength, they're measuring how much it would hurt you if you were climbing on one of these systems and took a fall on a very short piece of rope. (in effect, misusing the ropes- static ropes aren't for fall arrest, dynamic ropes rely of the length of the rope to stretch and absorb shock)

Yes, the scaffold knot is absorbing energy, but if you scaffold knot and do a break test or a dynamic drop test, the actual breaking strength will never come CLOSE to what a splice or stitched termination can do.

I just want to make sure we are being clear on what we're talking about. To summarize:

Post 1- in the original post, Gauge asked about strength of a splice
Post 6- Rope Armour states that the scaffold is stronger
Post 9- I'm like, "no way"
Post 10- Knot rigger says, "in the right rope under shock loading, a knot can be stronger than a splice."

All I'm trying to say is that a knot can never be STRONGER than a splice. A knot can be BETTER than a splice for different applications, but it can't be STRONGER.

(I hope I'm not coming across as a jerk!)

 

[Tommy_B]

I agree with post 9

 

[SouthSoundTree-]

Jerk! Jerk!

 

[pantheraba]

Nah, Nick. You are trying to keep the water clear.