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Old 19-01-2022, 01:38   #1
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loop to loop connection

Hi,
Could anyone please tell me for what reason is the bottom one 'wrong' here
I can see that it will be more difficult to remove when tightened but are there other reasons?
e.g. strength?

I ask because I need a loop to loop connection where chafe may be a problem and I think the 'correct' one will chafe if the tension is not constantly applied (I tried with a 'model' of two loops and I could easily push pull and the loops slide over each other)
Its not something I need to undo.
Cheers
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Old 19-01-2022, 02:19   #2
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Re: loop to loop connection

If you don't need to undo it a double sheet bend or fisherman's knot would serve you better.
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Old 19-01-2022, 02:33   #3
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Re: loop to loop connection

Quote:
Originally Posted by Tupaia View Post
If you don't need to undo it a double sheet bend or fisherman's knot would serve you better.

Thanks, but they are spliced loops in 1" 3 strand
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Old 19-01-2022, 02:42   #4
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Re: loop to loop connection

Generally, the lead under tension is strongest if it enters straight into the knot and goes thru as gentle of a turn as possible. Sharp bends in the line tend to have less strength.

The "wrong" option has very sharp bends on the one side.

What is the connection type that you are worried about chafe?
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Old 19-01-2022, 02:51   #5
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Re: loop to loop connection

Quote:
Originally Posted by valhalla360 View Post
Generally, the lead under tension is strongest if it enters straight into the knot and goes thru as gentle of a turn as possible. Sharp bends in the line tend to have less strength.

The "wrong" option has very sharp bends on the one side.

What is the connection type that you are worried about chafe?

Thanks!


I was trying to avoid this to avoid mooring discussions involving hurricanes


Its for my 1250 kg ETAP 22 in a sheltered, estuarine enclosed bay, shallow swinging mooring.
I have an eye splice at the top end and need to attach another spliced eye to it.

All splices are done in 1" 3-strand.

I am going to try without hard thimbles and shackles to avoid corrosion.

It is easily inspected every time I get to the boat which is 10 mins away.
I also have some 4-laminate fire hose that I could put around the loops (I would have to cut open and then sew together) but then I cant see the state of the rope
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Old 19-01-2022, 06:31   #6
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Re: loop to loop connection

You could lash the two eyes together with many wraps of thinner rope, say 1/4 or 3/16 polyester double braid. There are many ways to do a lashing, but I'd essentially wrap the line around five or six times, then tie the ends together with a alpine butterfly. When tensioned, all the legs will adjust to take the pull evenly, and you'll always be able to get it undone.
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Old 19-01-2022, 06:48   #7
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Re: loop to loop connection

I can only find references to this knot in fishing line. Is this knot not appropriate for other types of rope?
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Old 19-01-2022, 06:57   #8
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Re: loop to loop connection

Quote:
Originally Posted by Benz View Post
You could lash the two eyes together with many wraps of thinner rope, say 1/4 or 3/16 polyester double braid. There are many ways to do a lashing, but I'd essentially wrap the line around five or six times, then tie the ends together with a alpine butterfly. When tensioned, all the legs will adjust to take the pull evenly, and you'll always be able to get it undone.

Thanks.
Do you mean do the 'correct' loop to loop connection then lash the loops together to reduce chafe?
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Old 19-01-2022, 07:00   #9
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Re: loop to loop connection

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Originally Posted by cal40john View Post
I can only find references to this knot in fishing line. Is this knot not appropriate for other types of rope?



You mean my original post loop to loop?
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Old 19-01-2022, 08:52   #10
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Re: loop to loop connection

Quote:
Originally Posted by Malagueta View Post
You mean my original post loop to loop?
After looking at your link, I did a search. Everything I found for how to tie this knot was only in fishing line.

So I'm wondering if this knot does not work well with larger diameters or different materials for some reason.
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Old 19-01-2022, 15:09   #11
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Re: loop to loop connection

Quote:
Originally Posted by cal40john View Post
After looking at your link, I did a search. Everything I found for how to tie this knot was only in fishing line.

So I'm wondering if this knot does not work well with larger diameters or different materials for some reason.

I found this climbing video which calls it a strop hitch


And ABOK #1495
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Old 19-01-2022, 15:26   #12
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Re: loop to loop connection

Honestly, with the size of line and the light weight of your vessel I don't think chafe between the two loops will be a practical worry. Once the loops are even lightly loaded there should be very little motion between them, and the cordage is operating at such a low fraction of it's WLL that I wouldn't be concerned were it mine!

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Old 19-01-2022, 15:46   #13
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Re: loop to loop connection

Quote:
Originally Posted by Malagueta View Post
Thanks.
Do you mean do the 'correct' loop to loop connection then lash the loops together to reduce chafe?
No, I mean that without touching each other, the loops are placed a few inches apart, and you thread lighter line between the loops, making several passes, then tie the ends of the lighter line together. The thing that now connects the two bigger ropes is the multiple pass matrix (selvagee, technically) of lighter line.
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Old 20-01-2022, 01:49   #14
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Re: loop to loop connection

Thanks for all replies,
I now have a plan
It may not be the 100% optimised plan, but its my plan

I like @Jim Cate's comment - I think I am being fussy - the WLL of 1" nylon is around 5000 lbs / 2250 kg which means I could pretty safely lift two of my boat with a crane with one rope (well the tensile strength is around 25000 lbs / over 11 tonnes, so for sure).

I am a bit wary of @Benz's idea of lashing without interlocking the loops since then its a 'weakest-link' strength when the lashing ropes only needs a few strands to be cut for it to fail but I like the idea of lashing the loops together after doing the 'strop hitch' in a way that keeps them together (just for my own peace of mind)


Like I said, I'm making everything so that I can check the connections at low tide as well


I also learnt more about knots from the other comments

Thanks all!
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Old 20-01-2022, 04:13   #15
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Re: loop to loop connection

With enough turns, the lashing can be the strongest link. If something is going to cut the lashing, won't it cut the big rope as well? How much of the big rope can you afford to have cut before it's no longer big?
I'd say it's better to avoid things that cut.
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