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20-06-2016, 11:53
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#91
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Senior Cruiser
Join Date: Aug 2009
Posts: 4,033
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re: Unveiling the BB Soft Shackle
^^ just need to train the bow help better
I am always impressed with how clear the water you anchor in is.
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20-06-2016, 12:02
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#92
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Registered User
Join Date: Jan 2010
Location: Puget Sound, USA
Boat: Lyman-Morse 54
Posts: 219
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re: Unveiling the BB Soft Shackle
Quote:
Originally Posted by Seaworthy Lass
It is essentially a High Strength shackle design with a central unsecured bury to make handling nicer. I also think when used between snubber and chain the single central portion is less likely to get pinched between the links of the chain than the two thin legs in a standard HS shackle are.
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Very nice!
Just wondering out loud... does having the single central portion potentially create any issues in that the outer portion takes all the chafe instead of spreading it between the two legs (admittedly not necessarily evenly) in the non-buried HS shackle version?
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20-06-2016, 21:35
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#93
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Moderator
Join Date: Oct 2008
Boat: Bestevaer 49
Posts: 16,151
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re: Unveiling the BB Soft Shackle
Quote:
Originally Posted by Pyxis156
Very nice!
Just wondering out loud... does having the single central portion potentially create any issues in that the outer portion takes all the chafe instead of spreading it between the two legs (admittedly not necessarily evenly) in the non-buried HS shackle version?
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I have thought about this before and it did my head in .
Chafe is very unlikely to be even between two legs, but with the single central portion the outer part increases in diameter and thins to fit over the inner part. This may wear more easily?
UV degradation is another aspect. Uncoated dyneema relies on UV deteriorating the outer layers and not penetrating further. Is the deterioration therefore worse if the outer part has thinned when surrounding a bury?
Some companies are now coating dyneema for increased UV and chafe resistance. I don't know if this is done before or after weaving the line. Again, the thinner outer layer in the single central portion may deteriotate more quickly than untouched single legs do.
Anyway, chafe is easy to see and I think in vital situations where subjected high loads and especially shock loads, soft shackles should be replaced every 6-12 months, so UV is not a big concern.
On the other hand, a thin leg can get trapped between the links of chain far more easily than a thick one and would then be subject to high compression and chafe and this is what I am hoping to avoid by creating a central bury.
Evans, what do you think?
By the way, a central buried portion could also be incorporated easily in your Improved design. Leaving each end of the bury unlocked, as in the BB, means loads can be distributed reasonably easily between the two portions. The noose would still be the weak point in the arrangement. It does make the shackle nice to handle.
SWL
__________________
SWL (enthusiastic amateur)
"To me the simple act of tying a knot is an adventure in unlimited space." Clifford Ashley
"The cure for anything is salt water: sweat, tears or the sea." Isak Dinesen
Unveiling Bullseye strops for low friction rings
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21-06-2016, 10:23
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#94
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Senior Cruiser
Join Date: Aug 2009
Posts: 4,033
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re: Unveiling the BB Soft Shackle
^^
Regarding UV - I don't think it matters - Data says that uv penetrates 4mm into rope at almost full strength. So it is going to cook most of soft shackle in either configuration. note: in chain snubber application it is underwater - so uv not so much an issue.
Regarding chafe - it is a more complicated - we really need thinwater to test it. the two leg design will have (I think) lower psi, but also expose greater percent of fibers to damage - I am not sure which factor would win.
Regarding bend radius - you did not mention this aspect - but the one leg design creates a larger diameter, which makes it weaker in tight bend radius situations.
Overall my personal sense is that in terms of leg strength, the two leg designs are a little better, but that it does not matter because the noose weak point is the same in both designs, and the one leg design does have some functional and aesthetic advantages.
You are right the improved design could go partial single leg. I never optomized or modified that design because the early soft shackle adapters all liked symmetrical knots and found this one ugly.
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21-06-2016, 10:56
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#95
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Registered User
Join Date: Jan 2010
Location: Puget Sound, USA
Boat: Lyman-Morse 54
Posts: 219
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re: Unveiling the BB Soft Shackle
I guess when I was thinking about the chafe issue, my thought was primarily concerned with you are functionally using the "outside" leg as a chafe-guard for the inside leg, with the fibers in the outside leg taking 100% of the chafe damage as opposed to spreading the damage (potentially) between the two legs in the non-buried version. By concentrating all the damage in a single leg, could that possibly compromise the leg faster? I am thinking less of normal day-to-day use and more of a situation where you might be at anchor in high winds and / or experiencing some fetch waves leading to accelerated chafe, and you can't get to the shackle to check it for some time.
But I agree with you both, lots of variables and as SWL said, being a mission-critical piece of gear and how cheap and easy (relatively speaking) to make, regular replacement intervals and replacement at the first sign of chafe may deal with most of this issue.
I am also continually amazed at the chafe resistance of this material. I made a two-leg high-strength soft shackle last year and have probably 600-700 hours at anchor on it including a few 25-35 knot with higher gust episodes, and while discolored in places there are practically no signs of chafe at all.
Evans, you have said that you found differences in the various brands of dyneema line, and I believe you said your preference was for the Yale product. Would that opinion apply to line used in this application (i.e., for anchor snubbers)?
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21-06-2016, 11:15
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#96
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Senior Cruiser
Join Date: Aug 2009
Posts: 4,033
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re: Unveiling the BB Soft Shackle
Quote:
Originally Posted by Pyxis156
Evans, you have said that you found differences in the various brands of dyneema line, and I believe you said your preference was for the Yale product. Would that opinion apply to line used in this application (i.e., for anchor snubbers)?
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My "chafe" experience was from using single braid as mainsail clew reefing lines. And yes there was a quite high variation between brands, and yale was good, Amsteel less good. And this would apply directly to the anchor snubber application.
BUT that experience base is now quite dated and I would be reluctant to suggest which brand would be better today.
I believe thinwater' testing suggested product heavily saturated with coatings are much better at chafe, and that Yale rope I had good success with was heavily coated. There are also differences in uhmw fiber diameters used and braiding techniques that most likely effect chafe but I do not know enough to suggest which are better or worse.
Thinwater is your man for this . . . . He had a decent chafe testing set-up. Everyone ping him and plea for a brand/model chafe test
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21-06-2016, 16:26
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#97
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Senior Cruiser
Join Date: Aug 2009
Posts: 4,033
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re: Unveiling the BB Soft Shackle
Quote:
Originally Posted by Pyxis156
I guess when I was thinking about the chafe issue, my thought was primarily concerned with you are functionally using the "outside" leg as a chafe-guard for the inside leg, with the fibers in the outside leg taking 100% of the chafe damage as opposed to spreading the damage (potentially) between the two legs in the non-buried version. By concentrating all the damage in a single leg, could that possibly compromise the leg faster?
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I did one piece of testing relevant to this question, and the result was not completed expected. . . .
I took a piece of amsteel (a line made of 12 strands - 12 bundles of fibers) and cut half the fibers in each of three of the strands. That cuts 12.5% of the fibers, and damages 25% of the strands. I then broke it. The line broke at 23% below tensile. So, it appears to be the fraction of strands damaged that is important rather than the fraction of fibers. Explanation: The damaged strands cannot hold their rated proportion of the load and thus fail and then the rest of the line fails.
So, the question related to 1 leg or 2 is: in which are more strands (bundles not fibers) going to see damage. My guess is in the 2 leg solution.
But it could/should be that the higher chafe psi (because of reduced surface area) will actually cut more bundles faster in the single leg case.
So, I do not know the ultimate answer, but it would be a simple test to find out.
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22-06-2016, 08:04
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#98
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Moderator
Join Date: Oct 2008
Boat: Bestevaer 49
Posts: 16,151
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re: Unveiling the BB Soft Shackle
Quote:
Originally Posted by estarzinger
......
But it could/should be that the higher chafe psi (because of reduced surface area) will actually cut more bundles faster in the single leg case.
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That was my thought a few posts back.
I think it depends how the chafe is occuring which is more likely to occur.
So far chafe has not been much of an issue, even with the old original shackles that have had close to a year's use and they all had a long central buried portion.
My concern in the snubber to chain application is one of the legs getting trapped between the links. The likelihood of chafe will then skyrocket. I think a fatter central portion is less likely to get trapped.
SWL
__________________
SWL (enthusiastic amateur)
"To me the simple act of tying a knot is an adventure in unlimited space." Clifford Ashley
"The cure for anything is salt water: sweat, tears or the sea." Isak Dinesen
Unveiling Bullseye strops for low friction rings
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22-06-2016, 08:14
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#99
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Moderator
Join Date: Oct 2008
Boat: Bestevaer 49
Posts: 16,151
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re: Unveiling the BB Soft Shackle
The wind has picked up a bit here today, so the BB is not hanging limply any longer.
This is how it is looking:
http://i1377.photobucket.com/albums/...sfy85aevi.jpeg
__________________
SWL (enthusiastic amateur)
"To me the simple act of tying a knot is an adventure in unlimited space." Clifford Ashley
"The cure for anything is salt water: sweat, tears or the sea." Isak Dinesen
Unveiling Bullseye strops for low friction rings
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29-06-2016, 08:33
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#100
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Moderator
Join Date: Oct 2008
Boat: Bestevaer 49
Posts: 16,151
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re: Unveiling the BB Soft Shackle
I purchased dyneema in a variety of diameters before returning to Greece, so I am having a bit of a play .
This was a very diminutive BB made in 3mm last night. It was a bit of a struggle with no fids this size on board, but still manageable. To help prevent fumbling with small openings, I made the noose hold 6x line diameter.
Estimated breaking strain is around 2 ton. It was tightened only on a vice with a washer as backing, as high shock loads are not envisaged with usage of this one:
http://i1377.photobucket.com/albums/...stipgyj3e.jpeg
http://i1377.photobucket.com/albums/...swfkw6wpe.jpeg
__________________
SWL (enthusiastic amateur)
"To me the simple act of tying a knot is an adventure in unlimited space." Clifford Ashley
"The cure for anything is salt water: sweat, tears or the sea." Isak Dinesen
Unveiling Bullseye strops for low friction rings
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29-06-2016, 16:15
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#101
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Senior Cruiser
Join Date: Nov 2013
Location: Port Moresby,Papua New Guinea
Boat: FP Belize Maestro 43 and OPBs
Posts: 12,888
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re: Unveiling the BB Soft Shackle
2 x 4mm ones I made at the weekend.
(Please - no comments on the knot on the shorter one )
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29-06-2016, 20:33
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#102
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Moderator
Join Date: Oct 2008
Boat: Bestevaer 49
Posts: 16,151
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re: Unveiling the BB Soft Shackle
Quote:
Originally Posted by StuM
2 x 4mm ones I made at the weekend.
(Please - no comments on the knot on the shorter one )
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Hi Stu
They look beaut!
Do you always "lock" the opening portion after the noose? (ie cross which way the two insertions go?) I did initially, but the request from the bow was for an even easier opening, so now I let it slide freely. I am in two minds about this.
SWL
__________________
SWL (enthusiastic amateur)
"To me the simple act of tying a knot is an adventure in unlimited space." Clifford Ashley
"The cure for anything is salt water: sweat, tears or the sea." Isak Dinesen
Unveiling Bullseye strops for low friction rings
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08-03-2017, 22:13
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#103
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Registered User
Join Date: Feb 2014
Location: New Orleans
Boat: Kaufman 47
Posts: 1,184
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re: Unveiling the BB Soft Shackle
Quote:
Originally Posted by Seaworthy Lass
Here are instructions for making for a BB soft shackle and a rough guideline of measurements.
- Insert 4 lines through the loop and tighten up the loop lightly around them
- Tape the two lines together near the loop to secure and remove the 4 lines. The tip of the loop is A.
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Hey SWL,
I'm having trouble understanding these two steps.. How/where do I get 4 lines when I'm working with a single piece? I know I have two ends but 4 I'm not understanding. Then I tape what I assume is two more, then remove the original 4?
I made a couple "softie" shackles (colligo style) because they were easy and I wanted to start somewhere. I'm proficient in knots and splicing but I'm not understanding these steps. I'm using 5/16" amsteel blue and I have the tools. If you could throw me a bone that would be great because I'm excited to make these!
Ronnie
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08-03-2017, 23:06
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#104
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Moderator
Join Date: Oct 2008
Boat: Bestevaer 49
Posts: 16,151
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re: Unveiling the BB Soft Shackle
Quote:
Originally Posted by SailRedemption
Hey SWL,
I'm having trouble understanding these two steps.. How/where do I get 4 lines when I'm working with a single piece? I know I have two ends but 4 I'm not understanding. Then I tape what I assume is two more, then remove the original 4?
I made a couple "softie" shackles (colligo style) because they were easy and I wanted to start somewhere. I'm proficient in knots and splicing but I'm not understanding these steps. I'm using 5/16" amsteel blue and I have the tools. If you could throw me a bone that would be great because I'm excited to make these!
Ronnie
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Hi Ronnie
The 4 lines are used just to determine how big to make the noose (and I have actually found 5 to be a bit better when handling, so I will modify the instructions).
So just grab the 2 free ends, double them over so you have 4 bits and tighten the noose softly around that bundle (no need to be super tight).
Or use the end of the spare dyneema you have and create a bundle of 4 or 5 from that. More than 2 is needed, as the tails end up buried in the legs, roughly doubling the size that will be held by the noose.
This is an easy way of ensuring the noose is not too small, and also that it is not too large and you risk the stopper coming free with cyclical load (I have never heard that happening, even on a flogging headsail clew), but no need to take any chances .
SWL
__________________
SWL (enthusiastic amateur)
"To me the simple act of tying a knot is an adventure in unlimited space." Clifford Ashley
"The cure for anything is salt water: sweat, tears or the sea." Isak Dinesen
Unveiling Bullseye strops for low friction rings
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08-03-2017, 23:13
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#105
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Senior Cruiser
Join Date: Nov 2013
Location: Port Moresby,Papua New Guinea
Boat: FP Belize Maestro 43 and OPBs
Posts: 12,888
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re: Unveiling the BB Soft Shackle
Quote:
Originally Posted by SailRedemption
Hey SWL,
I'm having trouble understanding these two steps.. How/where do I get 4 lines when I'm working with a single piece? I know I have two ends but 4 I'm not understanding. Then I tape what I assume is two more, then remove the original 4?
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Just double up and tuck a piece of the line.
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