Double or Triple fisherman's loops

[Recon Freak]

I've been trying out some new hitches tying my own prussic cords and use the triple for my termination to my biner. 29" eye to eye give me the best performance with a 4-2 vt. I find though I need more length to try some other hitches and could get a few more inches using the double instead of a triple. Is the double a sufficient termination in this application? Which one do you use in your hitch systems?

 

[Kneejerk Bombas]

Double is fine for standard polyester cords, but the high molecular weight, low stretch ropes have such a slippery core, under high loads the cover tears and the core slides out. For these ropes, a triple fisherman's is needed for full strength.

 

[TheTreeSpyder]

Double Overhand, Double Noose, Scaffold, Fishermans etc. knot tests

Full/Full strength is great; but if any other bends/ compromises in lines/cords then shouldn't sweat tooo much making this link stronger than rest of the chain of support in that line. Thus, IMLHO the main facture is the security and not so much strength added by triple.

 

[moray]

I don't like knots for terminations when a splice is possible. But sometimes you have to do it. I agree with TheTreeSpyder that strength is not a worry. Mike Maas brings up a failure mode that I wasn't aware of.

But there is another failure mode that is maybe less obvious. I learned of this on a rock climber newsgroup. Someone decided to test some of the knots that climbers frequently use, especially the bends they use to connect long pieces of rope. They will actually hang from a rope that has a knot in the middle, which we don't do. The result was surprising. One or more of the commonly used bends would imperceptibly creep every time it was loaded with 150 lbs or so. The creep was about .001 inch per cycle. Even after 10 or 20 cycles, you would be hard pressed to see any change. But the experimenter kept at it, and after 1000 cycles, the knot had unrolled a whole inch with no change in shape or apparent security.

One of the most highly regarded bends used in the climbing world is the figure eight follow through, considered to be absolutely bullet proof. You could use this as a termination knot, but I don't know if it is any less prone to creep than a double or triple fishermans. Bottom line: if you use permanently installed knots, as on your lanyard prusik cord, inspect regularly! For a one-time use, as on your climbing line, just tie it well and forget about it.

 

[Kneejerk Bombas]

Double Overhand, Double Noose, Scaffold, Fishermans etc. knot tests

Full/Full strength is great; but if any other bends/ compromises in lines/cords then shouldn't sweat tooo much making this link stronger than rest of the chain of support in that line. Thus, IMLHO the main facture is the security and not so much strength added by triple.

Are saying the strength of the HMW cord tied with a Double Fishermen's Knot is high enough, even though it has a tested strength loss compared to a Triple Fishermen's Knot?

If so, I don't get that thinking.

 

[Kneejerk Bombas]

One of the most highly regarded bends used in the climbing world is the figure eight follow through, considered to be absolutely bullet proof.

What's a Figure 8 Follow Through?

 

[moray]

What's a Figure 8 Follow Through?

If you tie a figure 8 on a bight (you tie the whole thing with doubled rope), you effectively get a figure 8 follow through. If you tie an overhand on a bight, you get an overhand follow through. You end up with a loop in both cases.

If you want to tie one as a bend, or on a closed ring, you can't use that method.

For a bend, tie a very loose figure 8 in one rope near the end. Take the end of the other rope and insert it into the figure 8 where the end of the first rope emerges. Continue "following" the contours of the knot, hard against the first rope, through all the twists and turns, until the end of the second rope emerges from the knot alongside the standing part of the first rope. Now set and dress.

For a closed ring, start as above, but make sure the loose figure 8 is not too close to the end, as you need a lot of slack to finish. Feed the end through the ring, then insert it into the knot as above. Follow the knot till end emerges along standing part. Set and dress. The knot is correctly done when the two strands are parallel throughout the knot, with no crossing.

 

[Recon Freak]

Bee-line

Double is fine for standard polyester cords, but the high molecular weight, low stretch ropes have such a slippery core, under high loads the cover tears and the core slides out. For these ropes, a triple fisherman's is needed for full strength.

Bee-line would fall into the triple category then?

 

[Kneejerk Bombas]

Yes. The Bee-line has a Vectran core.

 

[TheTreeSpyder]

i like bright rope colors, with contrasting bright tape on the ends, ends of the same line with different bright colors. In 1/2" lines the tape is at least 2". i keep blue, red, yellow tape; so i usually have 2 contrasting colors for the line color.

With groundies 50' lower that becomes 'pick up the red end of blue, now the yellow end of red, no simon didn't say drop the red end of blue, how can you bend/tie them together then?'

But, for knots/climbing/rigging this becomes a safety marker 2 ways. If all the 2" tape flags/shows on a 1/2" line we have our proper 'tail' of 4x rope diameter in making knot. Also, we know there has been no creeps in use. The bright signal flares/flags especially on Scaffolds/Nooses/Fisherpersons whatevers, Bowlines etc. are a constant, easy, eye catching check of knot status for me; even at some distance.

 

[Tree Machine]

What's a Figure 8 Follow Through?

Moray 'splained it pretty well, but here's a Groggination of it.

http://www.animatedknots.com/fig8fo...ge=LogoGrog.jpg&Website=www.animatedknots.com

 

[Kneejerk Bombas]

I can see why it's a trusted knot, it has to come half way untied to get down to a bowline.
Plus the bulk of the knot reduces the bend radius, further increasing the strength.
Hard to believe that knot creeps undone.

 

[TheTreeSpyder]

i think Fig.8 Family is pretty wild; like a long half hitch version of knots. Easily identified, remembered partially cuz symmetrical and easier untying. i think they have these specialty mechaincs: longer to make wider bend/ gives less sharp bend 2 ways/ so stronger, also gives reserve to pull from and slide to absorb shox- so more dynamics, more grip distance/ footprint- so more secure etc. group.

The strengthening of longer to make same turn around self makes longer/wider ; though/not as compact, and these re-threads bulkier too, but that gives less sharp bends to the longer curve; if Standing Part as load is on outside arc; giving even more strength 'retention'.

 

[046]

here's a pic of my split tail using triple fisherman to terminate. note lashing is not for extra security.

good point MM made earlier about triple fish being used for slippery ropes. triple fish is the only termination knot recommended for spectra. triple fish is an ideal knot where you don't need to untie.

 

[TheTreeSpyder]

On a closed mount like eye of snap; the mating shrinking eye of Triple whatevers can be a pain to try to remove. But, on an open mount without metal threads, hooks etc. to grab at line, like krab; sliding the hitch off the smooth metal gives extra play room to break down the hitch for me.

i like my turns uncrossed on it. This way they ride higher, with a smoother flow of firming force; with less loss of this force (taking a RoundTurn on krab reduces this hitches strength, by reducing the firming forces in the turns i think; so would likewise do so in crossed turns?). These are also more smoothly tapered; and the Bitter End/ Working End seats tightly and squarely into top of the krab; which i'd think gives more security. If we cross turns to bring 1 of the wraps low to krab, we lose this suqare bite into the top of krab from what i can see.

 

[Kneejerk Bombas]

If you don't cross the loops, there's no untieing it once loaded.