Unveiling the BB Soft Shackle

[Seaworthy Lass]

And a couple of underwater shots. The fine white line is the marker I added to check how far the Button moves with use.

Firstly in a lull:

http://i1377.photobucket.com/albums/...psw8tx3xwf.jpg


Then in a slight gust:

http://i1377.photobucket.com/albums/...psdmrfsenf.jpg

Chain is about to be replaced.
This is how it looks after about 3.5 years use. The ends were reversed at the halfway mark.

SWL

[Pyxis156]

SWL, thank you very much for sharing your efforts. I am in the process of a complete redesign of our snubbing solution and this is exactly along the lines of what I hope to implement. Same goes to Evans, very happy to see you posting on this topic despite "retirement"! I have read and reread the soft shackle and load testing work on your website many times the past few months... both of you hugely helpful!

I don't want to hijack the thread but have a question that seems related enough to post here. Other than aesthetic, what might the pros and cons of using a dogbone for this application be? I am thinking that mating 3/8" (9mm) Amsteel-Blue with something like the Tylaska DB12SS stainless steel dogbone (SWL 6,500lbs/2,950kg, breaking strength 13,000lbs/5,900kg) could make a robust shackle for a snubber without the concern of the knot possibly compromising the shackle if not executed perfectly. The splices would be easier to implement as well, and you could possibly use the dogbone to help open the eye up when you release the shackle. I know that a dogbone, especially this size, could be painful if not deadly in other typical on-deck soft shackle uses, but for a snubber where it isn't going anywhere it seems almost ideal.

Your thoughts greatly appreciated...

[Seaworthy Lass]

Originally Posted by Pyxis156

SWL, thank you very much for sharing your efforts. I am in the process of a complete redesign of our snubbing solution and this is exactly along the lines of what I hope to implement. Same goes to Evans, very happy to see you posting on this topic despite "retirement"! I have read and reread the soft shackle and load testing work on your website many times the past few months... both of you hugely helpful!

I don't want to hijack the thread but have a question that seems related enough to post here. Other than aesthetic, what might the pros and cons of using a dogbone for this application be? I am thinking that mating 3/8" (9mm) Amsteel-Blue with something like the Tylaska DB12SS stainless steel dogbone (SWL 6,500lbs/2,950kg, breaking strength 13,000lbs/5,900kg) could make a robust shackle for a snubber without the concern of the knot possibly compromising the shackle if not executed perfectly. The splices would be easier to implement as well, and you could possibly use the dogbone to help open the eye up when you release the shackle. I know that a dogbone, especially this size, could be painful if not deadly in other typical on-deck soft shackle uses, but for a snubber where it isn't going anywhere it seems almost ideal.

Your thoughts greatly appreciated...

Toggles have been tried:

http://www.cruisersforum.com/forums/...le-133979.html

The original tested in the above link was wooden. Evans also tested machined aluminium (grooved centre).

They are strong, and easy to handle and they are used racing. The drawback is that, as you mention, you no longer have an all soft shackle.

I think the Button that Brion Toss designed is a huge breakthrough in soft shackles. The all soft nature appeals to me (no scratching of paintwork or gelcoat or bashing against skin). It is a LOT easier to use compared to the Diamond.

I was hauled up the mast yesterday and took all my 5mm BB soft shackles with me. The lack of a tail sticking out of the stopper was fabulous. I could operate one single handed, as I could shove the stopper through the loop sidewards, or absolutely any way. With the Diamond it must be head first or the tail snags. I am hooked on the Button as a stopper! I guess though that there would be lots of applications the toggle would serve better, particularly if someone was not enthusiastic about acquiring knot tying skills.

SWL

[jcapo]

I made another BB style shackle and I noticed a few things.

The legs must be the same length after the knot is tightened to get equal loading.

The bury must be the same length with the same taper in both legs or one leg will be slightly longer due to shrinking when a core is inserted. Visually one leg will be longer, the knot sits at an angle on the tails. Under load it may not make a difference.

Load up the shackle to 1000+ lbs a few times and it starts looking a bit ratty where the tails exit the knot. The buries can work out of the cover a bit at the knot especially if you flex the tails at the knot. Stitching may help this situation.

The BB style has been around for a while in the off road domain but without the tails being buried.



The tails hold their shape at the knot better when I used this method.

Like the last time I tried this BB style, I'm not convinced its better than Allen's "better" style unless you really need the extra strength from more mass in the tails at the noose. I tension the conventional diamond knot to over 1000 lbs and cut the tails short. The tails don't get in the way and I haven't been able to suck them in at all with my cockpit winches.

I'm gonna play with the BB some more. Maybe I'll change my mind.

[Seaworthy Lass]

Originally Posted by jcapo

I made another BB style shackle and I noticed a few things.

The legs must be the same length after the knot is tightened to get equal loading.

The bury must be the same length with the same taper in both legs or one leg will be slightly longer due to shrinking when a core is inserted. Visually one leg will be longer, the knot sits at an angle on the tails. Under load it may not make a difference.

Load up the shackle to 1000+ lbs a few times and it starts looking a bit ratty where the tails exit the knot. The buries can work out of the cover a bit at the knot especially if you flex the tails at the knot. Stitching may help this situation.

The BB style has been around for a while in the off road domain but without the tails being buried.



The tails hold their shape at the knot better when I used this method.

Like the last time I tried this BB style, I'm not convinced its better than Allen's "better" style unless you really need the extra strength from more mass in the tails at the noose. I tension the conventional diamond knot to over 1000 lbs and cut the tails short. The tails don't get in the way and I haven't been able to suck them in at all with my cockpit winches.

I'm gonna play with the BB some more. Maybe I'll change my mind.

All useful info . Thanks for the feedback.
Not having 'locked' ends for the central bury should help equalise load on the legs. In this last example I left out the lock at the knot end the the central bury. Next time I will do so at the loop end as well.

When I use an open clutch & winch to pretension the Button I will bury the working ends after this is done. I wonder if that may solve some of the issues? Equal tension is important within both the Diamond and Button. I use the technique of marking the working ends the same length before tying both of these stoppers and frequently check during tightening that they are the same length.

Regarding the tails sticking out unburied from the base of the Button. I think there would not be any significant strengthening of the base of the stopper then and it looks a bit messy. I made one like this before trying the buried tail version. In the end I buried one tail within the other to neaten it up and secured it with a constrictor knot.

I have never been game to cut the tales short on a Diamond knot . I think it would have to be flush with the stopper to avoid the tails catching when pushing the knot through sidewards.

I have had extremely limited use with the Button. It will be interesting to see how it fares in practice over the next year. So far I am very impressed.

I am not keen not keen on having the Button and two legs for the full length, as the High Strength one does, for use on the snubber. I think one leg could easily jam between the chain links and the tension distribution would then be unequal, weakening the soft shackle. Maybe the load would equalise, maybe not. The central buried portion to me seems better in this application. The Button bit of the High Strength seems brilliant though and the increase in strength with the bury of the tails is very appealing.

SWL

[Seaworthy Lass]

I have not see this reported before, but 6mm Amsteel Blue thickens substantially with time under water, making it much harder to shove in a chain link.

This soft shackle has been used to connect snubber to chain for around 6 months. Milking back the outer layer to expose the still blue buried portion, demonstrates this.

The buried inner portion has a diameter of around 5.5 mm.
The exposed portion is about 9 mm. It can be compressed, but not a lot:

http://i1377.photobucket.com/albums/...pslhm5qsw9.jpg

[jcapo]

Originally Posted by Seaworthy Lass

Not having 'locked' ends for the central bury should help equalise load on the legs. In this last example I left out the lock at the knot end the the central bury. Next time I will do so at the loop end as well.

I omit the lock at the knot end also. If you omit both locks I think you are back to milking.

Originally Posted by Seaworthy Lass

When I use an open clutch & winch to pretension the Button I will bury the working ends after this is done. I wonder if that may solve some of the issues?

I tried it both ways and the core works out easily if you flex at the knot. I made one with a Samson style lock stitch and the cores stay put. Not sure how that will hold up with use.

Originally Posted by Seaworthy Lass

I have never been game to cut the tales short on a Diamond knot . I think it would have to be flush with the stopper to avoid the tails catching when pushing the knot through sidewards.

With the way I pre-tension and the tails cut to 1/4", inserting side ways with one hand is a bit more difficult. Two hands is not a problem. The diamond knot is tightened to over 1000lbs tails to noose, not in closed shackle configuration. The knot is quite small and steel hard.

Here's another off road shackle with two colors of line. Must be dipped rather than two separate lines.

[Seaworthy Lass]

Originally Posted by jcapo

I omit the lock at the knot end also. If you omit both locks I think you are back to milking.



I tried it both ways and the core works out easily if you flex at the knot. I made one with a Samson style lock stitch and the cores stay put. Not sure how that will hold up with use.



With the way I pre-tension and the tails cut to 1/4", inserting side ways with one hand is a bit more difficult. Two hands is not a problem. The diamond knot is tightened to over 1000lbs tails to noose, not in closed shackle configuration. The knot is quite small and steel hard.

Here's another off road shackle with two colors of line. Must be dipped rather than two separate lines.

That's a cool looking shackle! Is it a Button used? It looks exactly like a BB. What have they called it? Has it filtered to marine use yet?

I have just enough Amsteel left to make one more 6mm soft shackle, so I am having a bit of a think before I use this up.

If I leave out the lock near the loop end of the bury, the insertion point will serve as a 'stop' so I don't think that milking would be necessary. One of the lovely things is avoiding that, as it becomes much harder as the shackle ages underwater.

I have been bending the button back and forth in a couple of BBs, but I can't get the tails to come out. My insertion for the bury is very close, as recommended by Evans. That looks like it helps, as the legs simply won't bend much near the base of the button once the tail has been buried.

Regarding loading the BB after the tighten in the vice, I need to rethink how I do that. I have been banned from going near the clutch .

SWL

[CAELESTIS]

The button knot looks superior to the diamond knot, but I don't see how you can get enough tension on it to lock it. Currently I make the Kohlhoff style and leave enough of a tail after the diamond knot for the tails to be spliced into each other, forming a loop. I then take the loop to a jib sheet, and the other end to a metal shackle. The last step is to crank on the Harken 74 3sp until the line sounds like a piano wire, locking the knot. Cut the loop off and leave about 3/8 inch.

I sometimes place a sharpie mark on either side of the diamond knot when I have it tightened by hand as best I can, then see roughly 3/4inch more on either side after it gets the Harken treatment.

[Seaworthy Lass]

Originally Posted by CAELESTIS

The button knot looks superior to the diamond knot, but I don't see how you can get enough tension on it to lock it. Currently I make the Kohlhoff style and leave enough of a tail after the diamond knot for the tails to be spliced into each other, forming a loop. I then take the loop to a jib sheet, and the other end to a metal shackle. The last step is to crank on the Harken 74 3sp until the line sounds like a piano wire, locking the knot. Cut the loop off and leave about 3/8 inch.

I sometimes place a sharpie mark on either side of the diamond knot when I have it tightened by hand as best I can, then see roughly 3/4inch more on either side after it gets the Harken treatment.

Neat solution .

The only tensioning I have ever done has been by hand using a marlin spike, then popped in a vice (threaded through a washer and an alu rod inserted through the loop and the rod pulled).

Early Diamonds slipped about a cm in the vice, later ones where I used all my strength on the marlin first, have barely shifted at all. The stopper has moved a little further when loaded in use, but not much.

Evans suggested tensioning and then leaving 20 min to settle under tension is advisable, so I am trying to think how I can do this with the Button.

SWL

[Seaworthy Lass]

Wonder if it would work eye splicing each end of a couple of bits of Dyneema just big enough to thread the soft shackle through (two bits would mean load could be more even), then tightening between two winches?

The attachment on one end is the loop on the shackle. On the other end it is the pair of eye splices.

SWL

[Stumble]

I really want to know where they got that lime green dyneema from...

[Seaworthy Lass]

Originally Posted by Stumble

I really want to know where they got that lime green dyneema from...

I have seen images of pink ones I have coveted .

What Dyneema do you prefer using? I bought an assortment when back home a couple of years ago - Amsteel Blue (in blue and grey), another brand from a local chandlery and some online.

The Amsteel Blue stood out a mile as being the best. The online stuff was dreadful - the individual strands snagged easily on finger nails and the tail of the Diamond, and pulled out in loops. Horrid stuff. Amsteel has no tendency to do that.

SWL

[Stumble]

It really depends. I buy spools of 'lash it' in 1.75mm for really small soft shackles, and light lashings. Amsteel for general use, I am ordering some Marlow D12 MAX 78 for standing rigging, and other stuff for specialized use.

I like the colored stuff, but always seem to wind up with grey just because it's all my local shops carry. I keep being tempted to just suck it up and buy some spools so I can get bulk pricing, but I just can't justify owning 600' in multiple sizes so instead I overpay and keep 100' lengths around.


Oh, they don't make pink amsteel, it's faded red (it fades pretty quick).

[jcapo]

Originally Posted by Seaworthy Lass

That's a cool looking shackle! Is it a Button used? It looks exactly like a BB. What have they called it? Has it filtered to marine use yet?

It looks like a button knot and all four lines exit in the same direction. I haven't bought one. The price is a but steep for me.

Gator-Jaw® Soft Shackles • Bubba Rope