Which Klemheist implementation is stronger?

[cooties]

Which is better for strength for attaching a bridle to chain/rode ?

A: Klemheist knot made from a length of rope that has an eye splice at each end, with a single soft shackle threaded through both eyes

or

B: klemheist knot made from a continuous loop, through which the soft shackle is threaded.

I am guessing A?

Also I wonder if anyone could check my thinking.

I'm trying to size the rope used for the klemheist component. I have the following:
* candidate for klemheist knot, 5/16" (8mm) dyneema which has a minimum breaking strength of 12,300lb.

* bridle legs: 3/4 3-strand nylon and have each an avg breaking strength of 17,150 (don't know the minimum).

* 3/8" (10mm) g43 chain (50meters) with about 5400 WLL (safety factor is 3:1)
* 50m of 5/8" 3-strand nylon rode, with around 11,650 avg strength

The 3 strand rode is the weak point, with a safety factor of 3:1 making it about 3800lb, but i have the chain for most situations. working load at 3:1 for the 5/16" dyneema would be about 4100, but does using two eyes increase that?

I also have a bunch of 1/2" (12mm) dyneema with 30,600 min break, but I don't imagine that's appropriate for this link - and would it even hold well to the 5/8 rode? This stuff was intended for making soft shackles.

So my questions are, is the 5/16" dyneea appropriate for the klemheist knot, and should I use a loop or a length with two eyes for connecting the klemheist to the soft shackle (which then connects to a 1/2" dyneema continuous loop which connects the bridle legs)

Thanks for advice!

[cooties]

I may have goofed a bit - as a continuous loop entails increasing the diameter and thus strength of the entire thing.. Maybe starting with an even smaller diameter (1/4"?) would be appropriate.

[cooties]

I am also I think forgetting that the tension in the loop is half, so perhaps the 8mm loop, with just 60 times the diameter buried in both sides, is enough strength to take care of this. Is that right?


And if I wanted a loop with a circumference of 2meters (to allow for 6 wraps of the 1meter doubled length around 5/8" rode), the entire length of the rope to make the loop would be 2 meters + 2x 60x 8mm = 2.96m, to account for the buried ends. Sure, it'd be a bit thicker over .96 of the 2m, so three of the 6 wraps would be larger - actually might not be able to get but 2 out of the last desired 3.. for 5 total. That should be good..?


Is this the right way to go about this?

[Benz]

All your thoughts are fine. I'd do a loop, since it'll be easier to get even loading than with two eyes. Make sure you lockstitch or whip the crossover (where the two tails bury into the body). Inspect the loop frequently. You would be fine with 1/4", I'll bet, but if the 5/16" isn't too fat for the klemheist to grip the rode, and you have it already, why not use it?
60 X the diameter is more than sufficient. Make sure you taper the bury tails, beginning at about halfway along the tail.

[MikeDofFreo]

I have always thought that a snubber should add the ability to stretch and absorb shock loads. So why would one use Dyneema ?

[Benz]

Originally Posted by MikeDofFreo

I have always thought that a snubber should add the ability to stretch and absorb shock loads. So why would one use Dyneema ?

It is only the attachment that is Dyneema. The rest of the bridle is nylon.

[hlev00]

Benz said just was I was going to reply with so consider his statement seconded.


harry

[Kd9truck]

If you are looking for a rope that has the strongest fiber with the lowest diameter I would offer Technora. It is an Arimid, very similar molecularly to Kevlar, it is most often spun in kernmantle arrangement. It is static, which is to say that it does not stretch, so any load will be transferred to the components of lesser load capabilities.

Technora Filament Yarn Advantages:

Excellent resistance to heat degradation
Excellent tensile strength and fatigue resistance
Superior resistance to chemicals and salt water
Adjustable to different applications
Long-term dimensional stability

Cheers��

[valhalla360]

Sounds complicated. After reading your description a couple times, I still don't fully follow.

We just used a long dock line (50ft on a 14ft beam).

Knot in the middle, then cleated each end off on a separate bow. Then release the anchor line so there was enough slack to let the bridle carry the load. If you wanted to adjust the length/tension of each leg, you simply took up more or less line before cleating.

[flee27]

I am not very experienced with using soft shackles like this. Would this set up not increase the number of places for chafe to be a problem. If I am understanding correctly you would be connected 2 eye splices with a soft shackle. So basically creating 3 loops connected together.

Thanks for the education.

Foster

[thinwater]

What is "chain/rode"? It is either a chain rode or a rope rode. I assume you mean "chain or rope."

I think if you Google it, you will find a Klemheist knot does not grip as well as a prusik, so give that up. Most sailors that use a gripping hitch use either a rolling hitch (good on rope, slips on chain), prusik, or thread a soft shackle.

Use a loop instead of a dog bone. Climbers always do it that way on both knots because that is how you equalize the pull. A dog bone is not an improvement, it is actually weaker for a given size.


5/8" nylon is light for a 51' cat. You want to reconsider that. The working load of nylon is only about 10% of the breaking strength.

[doublewide]

For connecting a bridle to rode or chain I recommend a Prusik loop. It uses the same principle as a Kleimheist, but owing to the loop form, it’s always loaded equally.
You can find instructions for making a dyneema Prusik online