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19-01-2022, 00:38
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#1
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Registered User
Join Date: Jan 2022
Location: Near Lisbon, Portugal
Boat: ETAP 22
Posts: 58
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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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19-01-2022, 01:19
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#2
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Registered User
Join Date: May 2014
Boat: Shuttleworth Advantage
Posts: 2,246
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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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19-01-2022, 01:33
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#3
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Registered User
Join Date: Jan 2022
Location: Near Lisbon, Portugal
Boat: ETAP 22
Posts: 58
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Re: loop to loop connection
Quote:
Originally Posted by Tupaia
If you don't need to undo it a double sheet bend or fisherman's knot would serve you better.
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Thanks, but they are spliced loops in 1" 3 strand
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19-01-2022, 01:42
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#4
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Registered User
Join Date: Apr 2013
Posts: 11,002
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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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19-01-2022, 01:51
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#5
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Registered User
Join Date: Jan 2022
Location: Near Lisbon, Portugal
Boat: ETAP 22
Posts: 58
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Re: loop to loop connection
Quote:
Originally Posted by valhalla360
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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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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19-01-2022, 05:31
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#6
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Marine Service Provider
Join Date: Dec 2010
Location: Little Compton, RI
Boat: Cape George 31
Posts: 2,976
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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.
__________________
Ben
zartmancruising.com
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19-01-2022, 05:48
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#7
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Registered User
Join Date: Dec 2006
Location: Seattle
Boat: Cal 40 (sold). Still have a Hobie 20
Posts: 2,944
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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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19-01-2022, 05:57
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#8
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Registered User
Join Date: Jan 2022
Location: Near Lisbon, Portugal
Boat: ETAP 22
Posts: 58
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Re: loop to loop connection
Quote:
Originally Posted by Benz
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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Thanks.
Do you mean do the 'correct' loop to loop connection then lash the loops together to reduce chafe?
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19-01-2022, 06:00
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#9
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Registered User
Join Date: Jan 2022
Location: Near Lisbon, Portugal
Boat: ETAP 22
Posts: 58
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Re: loop to loop connection
Quote:
Originally Posted by cal40john
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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You mean my original post loop to loop?
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19-01-2022, 07:52
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#10
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Registered User
Join Date: Dec 2006
Location: Seattle
Boat: Cal 40 (sold). Still have a Hobie 20
Posts: 2,944
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Re: loop to loop connection
Quote:
Originally Posted by Malagueta
You mean my original post loop to loop?
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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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19-01-2022, 14:09
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#11
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Registered User
Join Date: Jan 2022
Location: Near Lisbon, Portugal
Boat: ETAP 22
Posts: 58
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Re: loop to loop connection
Quote:
Originally Posted by cal40john
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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I found this climbing video which calls it a strop hitch
And ABOK #1495
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19-01-2022, 14:26
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#12
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Moderator
Join Date: May 2008
Location: cruising SW Pacific
Boat: Jon Sayer 1-off 46 ft fract rig sloop strip plank in W Red Cedar
Posts: 21,151
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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!
Jim
__________________
Jim and Ann s/v Insatiable II, lying Port Cygnet Tasmania once again.
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19-01-2022, 14:46
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#13
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Marine Service Provider
Join Date: Dec 2010
Location: Little Compton, RI
Boat: Cape George 31
Posts: 2,976
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Re: loop to loop connection
Quote:
Originally Posted by Malagueta
Thanks.
Do you mean do the 'correct' loop to loop connection then lash the loops together to reduce chafe?
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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.
__________________
Ben
zartmancruising.com
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20-01-2022, 00:49
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#14
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Registered User
Join Date: Jan 2022
Location: Near Lisbon, Portugal
Boat: ETAP 22
Posts: 58
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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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20-01-2022, 03:13
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#15
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Marine Service Provider
Join Date: Dec 2010
Location: Little Compton, RI
Boat: Cape George 31
Posts: 2,976
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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.
__________________
Ben
zartmancruising.com
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