Splicing nylon rode to chain

[thinwater]

Originally Posted by HopCar

I've done a lot of tapered back splices three strand to chain. No one has ever had a problem getting them to go through combination chain/rope gypsy. I'm actually surprised at how little chafe there is between the rope and chain.

My gypsy (Lewmar 700) has always hated 3-strand tapered backsplices. I've tried variations and even dared a local rigger to make it work (he bought me a beer after loosing, but I bought him one in return. He's a nice guy).

I've gone to using a 2-strand variation based on a long splice. I feeds like silk and the reading I have done suggests the strength is the same, since the load sharing is more equal (it is more symmetrical). It is slightly more complicated, but not bad; I did have to cut the first attempt out because I mis-guaged the lengths, a challenge on some splices.

I don't actually use the rope portion often, since I have enough chain to anchor on that 95% of the time. I only did this because I was doing some in-line tandem anchor tests, and 20:1 scope is required!

Anyone use 2-strand splice?

[ryon]

Originally Posted by thinwater

My gypsy (Lewmar 700) has always hated 3-strand tapered backsplices. I've tried variations and even dared a local rigger to make it work (he bought me a beer after loosing, but I bought him one in return. He's a nice guy).

I've gone to using a 2-strand variation based on a long splice. I feeds like silk and the reading I have done suggests the strength is the same, since the load sharing is more equal (it is more symmetrical). It is slightly more complicated, but not bad; I did have to cut the first attempt out because I mis-guaged the lengths, a challenge on some splices.

I don't actually use the rope portion often, since I have enough chain to anchor on that 95% of the time. I only did this because I was doing some in-line tandem anchor tests, and 20:1 scope is required!

Anyone use 2-strand splice?

Do you mean that you drop one of the strands, or that you work the third into the other two, or?

[HopCar]

Hi Thinwater, I think we're talking about different things. When I say three strand I'm talking about regular three strand twisted rope as opposed to braided or plaited rope.

What do you mean by two strand splice?

[Frankly]

Probably the "irony splice". End up with only 2 lines (4 load sharing) around the chain link.

http://www.cruisersforum.com/forums/...da-164762.html

Tried to just copy picture but no luck with this da** Chromebook.

[estarzinger]

Yea, that is Brion toss' fav. Works fine if well done, but is a "high skill" splice.

I never had any trouble getting the back splice to feed thru a Lewmar (V4) - only trick was splice needed to be "soft" rather than "hard".

[thinwater]

Originally Posted by Frankly

Probably the "irony splice". End up with only 2 lines (4 load sharing) around the chain link.

http://www.cruisersforum.com/forums/...da-164762.html

Tried to just copy picture but no luck with this da** Chromebook.

Yes, that. I had never heard it called an irony splice. Unlay one strand way back, lead the 2 remaining strands around the link in opposite directions, and lay on of the strands back into the vacant grove (the other is tucked). Then splice the unlayed strand to the re-layed strand as though it were a long splice. Basically a hybrid of the back splice and long splice.

Perhaps I could get a regular back splice to pass if it was soft, but I think I was always concerned, right of wrong, about movement on the link and chafe potential. But I can tell you, the for my windlass, the difference is night and day. The backsplice jams nearly 80 5 of the time, requiring me to guide it by hand into the gypsy, which is quite dangerous, while the irony splice passes like nothing at all.

I'm going to do a little strength testing of my own, I guess. Not that I am any splicing guru, which in a way is a good thing. It means if I can get the strength, anyone with a little diligence should be able to.

[estarzinger]

Originally Posted by thinwater

I'm going to do a little strength testing of my own, I guess. Not that I am any splicing guru, which in a way is a good thing. It means if I can get the strength, anyone with a little diligence should be able to.

Brion claims in his testing that the 2 strand splice (irony) was measurably stronger than the 3 strand (back). That's not what I found - I found them to be statistically equal.

In the 3 strand splice it all seems to be about how evenly you tension/bend the three strands over the chain, as in normal link sizes they are jammed in there and overlapping and not so easy to evenly tension/bend.

[thinwater]

Originally Posted by estarzinger

Brion claims in his testing that the 2 strand splice (irony) was measurably stronger than the 3 strand (back). That's not what I found - I found them to be statistically equal.

In the 3 strand splice it all seems to be about how evenly you tension/bend the three strands over the chain, as in normal link sizes they are jammed in there and overlapping and not so easy to evenly tension/bend.

Then why is the irony splice so rare? Tradition? Ease (not much difference, once you work out the the lengths)? Perception? Or course, there are still those that favor either shackles and thimbles or shovel splices, so it can be a little like discussing wire terminations or anchors. When I first heard of it I though it sounded frail, but I was willing to be convinced I was wrong.

[ryon]

Skipmac makes the point in that "Seco South" link that:

Have been reading posts from Brian Toss and he makes an interesting claim; one that is counter intuitive to me and counter to what I have read in the past.

He states that a long rope/chain splice where the rope strands are woven into a multiple links of the chain is weaker than a splice that wraps around just the one link at the end, preferably his "traditional irony splice" but even the standard eye splice he claims is better.

He reasoning is that with the long, woven splice the rope strands pull out of the chain when tested to maximum load. I have never heard of this as a concern and in my experience never seen the slightest movement in a long rope/chain splice. Also, all I have ever read and learned about ropes is quite clear that knots are much weaker than splices because of the sharp turns and bends the rope makes in a knot vs the long, gradual turns used to make a splice. Both the irony splice and the eye splice onto the end link of the chain result in a very small radius loop of rope around the chain which to me should be a weak point.

"When testing to maximum load" SOMETHING is going to fail. Is it the rope, the chain, or the splice? With the backsplice method I'm certain that it will be the fibers of the rope as they tightly turn 180 degrees around that one link of chain.

[estarzinger]

Originally Posted by thinwater

Then why is the irony splice so rare?.

I don't know.
I would guess it is just much less known because splicing 3 strand to chain is not really an important thing. And it does not offer much advantage - we yachties are about the only ones who want a seamless rope to chain windless transition. The "back" style splice is better known because commercial applications do use loops in 3 strand.

[estarzinger]

Originally Posted by ryon

With the backsplice method I'm certain that it will be the fibers of the rope as they tightly turn 180 degrees around that one link of chain.

Interestingly, not necessarily. It depends on the diameter of the chain rod (relative to the diameter of one strand of the three strand) and the size of the chain link (is it big enough to spread out all three strands or are the crunched). And finally it will depend on if there is and sort of sharp weld or galvanizing edge on the rope - is on some chain and not on others)

Generally a 1:1 bend ratio inside a loop is surprisingly near 100% strength - because the bend weakens the rope by 50% but the loop doubles the strength - so you end up back near 100% - usually somewhere in the 90% range.

And if the chain link is large enough you can get better than 1:1 bend ratio's if the rope strands have room to spread out.

I have done break tests with chain where it always broke at the chain and other tests with other chain/rope combinations where it didn't. But in any case pretty much all combinations were plenty strong - MUCH more likely to break from chafe somewhere than because of the splice.

[ryon]

Originally Posted by estarzinger

. . . Generally a 1:1 bend ratio inside a loop is surprisingly near 100% strength - because the bend weakens the rope by 50% but the loop doubles the strength - so you end up back near 100% - usually somewhere in the 90% range.

Interesting thought!

[Frankly]

If I remember the "behind the name" it was that the long splice was required because of original manila line was too large to get three strands through the matching chain link. Along comes smaller synthetic line an now the three strands will pass through the matching link (return of the crown splice). Next we have high test chain and now the link is too small once again. And we are back to the long splice. Brion refers to the "irony of it all".

[thinwater]

Originally Posted by Frankly

If I remember the "behind the name" it was that the long splice was required because of original manila line was too large to get three strands through the matching chain link. Along comes smaller synthetic line an now the three strands will pass through the matching link (return of the crown splice). Next we have high test chain and now the link is too small once again. And we are back to the long splice. Brion refers to the "irony of it all".

Thanks for the tale! Yes, I use G43. If it were BBB it wouldn't matter.