Unveiling Bullseye Strops for low friction rings

[Breaking Waves]

Originally Posted by s/v Jedi

Does the location of failure change with bury length?

Yes, A 'full strength' button with properly buried legs breaks at the noose. A button without buried legs breaks at the base of the knot (like a diamond does).

The buried legs in the button are actually NOT primarily about bend radius. Rather they double the strength of the area exiting the knot, and the tails need to share the load to do that, and they need bury length in order to be able to share the load. As a secondary factor, compared to the diamond, they also increase the bend radius of the noose, so when the failure mode is shifted to the noose, that failure is at a higher point - but you need the tails buried in order to shift the failure mode to get that benefit.

On a properly made 'full strength' buried legs button (where you have both strengthed the knot exit and the noose bend radius) - the failure should be at the cross-over making the noose. Brion Toss and I worked out ways to strengthen that cross over. They are documented in that long ago SA thread. But at that point if you need greater strength you might as well just use one size bigger diameter line, or use toggle design with spliced/buried loops ends.

[Seaworthy Lass]

Originally Posted by ohthetrees

Seaworthy Lass, I love your work, your BB shackle is my go-to and I just made my 2nd and 3rd Bullseye strop after using #1 for a few months for my spinnaker tack line. On a 50' boat this sees some substantial loads.

(The bottom one in the picture is the used one. The other two still need to be pre-tensioned)

I'm interested in your comments on a modification I made. I really prefer the button knot to the diamond, so I just used a button in this case, and let the tails stick out the bottom instead of burrying in the legs as I do with the BB. I whipped the ends, and all seems well, and I get the advantage of one-handed operation of the shackle without the noose getting stuck on the hard burnt ends of the diamond knot. I can't think of a reason why this modification would be less strong than a diamond, and it might be stronger. Please let me know what you think of this modification, or any reservations you have.

Hi Ohthetrees
Sorry I am late to the discussion. We have not been in internet range this week. New found freedom with sailing restrictions lifting here .

I am glad you have found the design useful. We have had several of these Bullseye shackles in action around the boat for the last few years. If a very short, removable strop is needed with a low friction ring held snuggly, there is really no other good alternative.

You have tied beautiful looking Brion Toss Buttons. I am a huge fan, so it is nice to see these. I do agree that the stopper is much easier to use with a smoothly rounded end, particularly if fingers are cold or if trying to secure or undo this single handed.

I do not think there is any problem at all using the Brion Toss Button in this application. As has been pointed out the strength will, however, not be as high as a soft shackle made with buried legs, which is not possible with this design unless the strop is made long).

SWL

[Breaking Waves]

Originally Posted by ohthetrees

Because the legs they would bury into are not long enough before they get involved with the crossovers and curving around the low friction ring. If that was done, the bury would have to be very short indeed.

If it were me, I would just taper and bury them for esthetics. Even if too short to achieve strength benefits.

[Seaworthy Lass]

Originally Posted by Benz

...As for diamond knot tails being rough and catching, well, that's entirely up to you. You can melt them down tidily into a uniform plastic surface that's perfectly smooth and leaves your knot round and snag-free.

Hi Benz
Yes, if the Diamond stopper has been well pretensioned, the ends can certainly be cut and fused onto the top. In practice the soft shackles we use are generally upsized for handling and are not going to be subjected to loads anywhere near their breaking load, but you never know . I think it is nice to optimise strength where possible.

All the soft shackles I have seen sold in chandleries have been with Diamond knots with the ends fused down onto the stopper, but then again, break loads are generally listed as only being line strength. A well made soft shackle with a Diamond knot can achieve approximately 170% of line strength.

Interestingly, Southern Ropes sell these with the ends melted down for “Leisure Marine” use, but with a decent length of ends remaining for what they describe as “Soft Industrial” use. The photos below are from their Commercial catalogue.

Jedi, I think you would approve of the tails on their “Industrial” version. I prefer a “belt and braces” approach so I certainly did :

SWL

[s/v Jedi]

Originally Posted by Seaworthy Lass

Jedi, I think you would approve of the tails on their “Industrial” version. I prefer a “belt and braces” approach so I certainly did :

SWL

Yes, I did a stitched seizing of the two ends. Still looking the same today

But I’ve completely switched to the Brian Toss Button knots with buried tails. I’ve also been using seizings of low friction rings to railings, shrouds etc. using Spyderline (Dyneema core) that are attached like welded.

[s/v Jedi]

Look what I found online

[Seaworthy Lass]

Originally Posted by s/v Jedi

Look what I found online

WOW! That is the first Brion Toss Button I have seen for sale. Clearly no one told them the legs need to be buried to achieve all the benefits though (and that ones in lime green can’t do serious work ).

[purjoloek]

Hi I found this thread looking to make a shackle combined with a low friction ring. You all have really done some great work but what I didn't find was a layout of how to do this.

I made this schematic of what I have now guessed is how it is done and thought maybe it can possibly help someone else. With that said could someone who has made one tell me if it seems right?

I am wondering if a splice (locking?) needed before the diamond knot maybe to keep the ring from falling out?

[purjoloek]

Hi I found this thread looking to make a shackle combined with a low friction ring. You all have really done some great work but what I haven't located (yet?) was a layout of how to do this.

I made the following schematic from what I have now understood is how it is done which can maybe help somone else looking for how to do it. Is there anyone how has made one that can tell me if it seems right or not?

Looking at it I was wondering if a splice (locking?) is needed before the diamond knot maybe to keep the ring from falling out?



thanks for the help!

[purjoloek]

well, i just gave it a go and i think it turned out pretty good.. notwithstanding my stopper knot which is a special want-to-be-a-diamond-knot-but-i-messed-it-up-somewhere knot.

i used 4mm dyneema on a 30/15mm low friction ring.

I made this one starting at 110cm .. but based on the tails I could have done it safely with 20cm less to go around a stanchion.. maybe even 35 but then the diamond knot may be problematic and it will need to go around something quite small.

I will check if i can get it on the stanchions this weekend.

instructions
1. fold the line in half
2. splice a loop at the fold - this loop that is formed will slide in the finished product allowing the diamond knot to pass through. this is the "loop"
3. about 7cm from the previous splice put in a splice again passing the end through the line
4. pin the second splice so it won't slide and check that the loop slides open enough to get a diamond knot in/out
5. sinch the first splice loop (middle of the line) around a piece of your line doubled up - I do this so it will be tight in its resting position
6. where the second splice went, you place a splice in the loose end pulling the loose end all the way through and introducing a twist in the hole that is formed
7. in the twisted splice, open it up bigger if needed and now pull the "loop" back through the twisted splice thereby taking out the twist
8. wrap the lines around the low friction ring and snug up to your liking
9. tie a diamond knot,
10. check it goes around what you are planning, eg a stanchion
11. snug it up
12. snug it up some more.

[Seaworthy Lass]

Originally Posted by purjoloek

Hi I found this thread looking to make a shackle combined with a low friction ring. You all have really done some great work but what I haven't located (yet?) was a layout of how to do this.

I made the following schematic from what I have now understood is how it is done which can maybe help somone else looking for how to do it. Is there anyone how has made one that can tell me if it seems right or not?

Looking at it I was wondering if a splice (locking?) is needed before the diamond knot maybe to keep the ring from falling out?



thanks for the help!

Hi Purjoloek

Sorry I am late responding.

Your schematic is correct regarding the layout, but not regarding the proportions.

If you want a longer soft shackle then extend the distance between the eye and the locked Brummel.

The distance between the Diamond knot and the Brummel needs to be set so that the ring fits snuggly. The base of the Diamond then becomes the lock on the other side:

Wind the Bullseye weave around the LF ring so it is snug, but not overly tight. Mark this on both bits of dyneema at both ends, unwind it, measure the length of the two lines and average this (it is important that they finally end up the same length so the load is evenly distributed).

Then when you have created the Brummel lock, mark the two lines exactly at the determined length, weave the Bullseye (avoiding twisting the line) and tape the two lines together at the previously measured distance.

Remove the LF ring to make it easier to tie the Diamond stopper and tie the stopper so that the base sits precisely at the marks.

I will check out the method in your second post and respond later.

SWL

[Breaking Waves]

Originally Posted by Seaworthy Lass

Sorry I am late responding.

If you get a moment, you might look at the last page or two of the cow hitch thread. We could really use your research and creative skills to tell us what the best options are for rebraiding 12 strand.

We were discussing a technique for making brummels when they are not normally possible. It depends on rebraiding the rope, and my and Brion's tests results had high variability which I think was due to inconsistency in getting even strand tension in the rebraid. I know nothing about the pros and cons of various braiding techniques.

[purjoloek]

Originally Posted by Seaworthy Lass

Hi Purjoloek

Sorry I am late responding.

Your schematic is correct regarding the layout, but not regarding the proportions.
....

Thanks!!!

I will redo it tomorrow I have corrected the instructions above as well so as not to mislead anyone. EDIT : turns out my previous post can no longer be edited. apologies to anyone who gets confused by it, I hope you read further.

With that said, I was also thinking may be something would be needed to retain the LFR but on my test the fantastic braiding cinched it into place under any load and even without any load it seemed to fit well anyway.

as for my test, it fit well on my stanchion today.


thanks again!

[Seaworthy Lass]

My comments are in blue:

Originally Posted by purjoloek

well, i just gave it a go and i think it turned out pretty good.. notwithstanding my stopper knot which is a special want-to-be-a-diamond-knot-but-i-messed-it-up-somewhere knot.

i used 4mm dyneema on a 30/15mm low friction ring.

I made this one starting at 110cm .. but based on the tails I could have done it safely with 20cm less to go around a stanchion.. maybe even 35 but then the diamond knot may be problematic and it will need to go around something quite small.

I will check if i can get it on the stanchions this weekend.

instructions
1. fold the line in half

2. splice a loop at the fold - this loop that is formed will slide in the finished product allowing the diamond knot to pass through. this is the "loop"
This is generally called the “eye” (sometimes erroneously a “noose”). One tail is simply passed through the centre of the line, so it is not actually a “splice”.
The eye size needs to be determined before you proceed further, not in step 5.

3. about 7cm from the previous splice put in a splice again passing the end through the line
The minimum distance needed is just enough to enable the eye to be opened and the stopper passed through, there is no maximum distance between the base of the eye and the Brummel. If a longer soft shackle is needed it is here that the length is added.

4. pin the second splice so it won't slide and check that the loop slides open enough to get a diamond knot in/out
Try and determine this before so you are not disrupting the eye that you have taped so it holds its correct size while you work.

5. sinch the first splice loop (middle of the line) around a piece of your line doubled up - I do this so it will be tight in its resting position
- This needed to be done before you create the Brummel lock, not after.
- Making the eye just large enough to take a doubled piece of line is too small. You do not want the eye to be tight in its resting position when under load (this would create a circle not an eye with a good throat angle) and it allows no room for error. If you have not equalised the tension perfectly at the end and the eye ends up even a whisker smaller than needed to fit 2 lines then the strength will plummet. I currently make the eye large enough to take 4-5 lines if making a soft shackle with a Diamond stopper. This is still much smaller than the stopper itself.
- Once you have determined the eye size tape this tightly so it does not shift while you are creating the Brummel lock.
- Trim the longer end to match the shorter one exactly. This enables you to check that the legs are of equal length when you are finished. This then means the tension is distributed equally between the 2 legs and this will help maximise strength.

6. where the second splice went, you place a splice in the loose end pulling the loose end all the way through and introducing a twist in the hole that is formed
7. in the twisted splice, open it up bigger if needed and now pull the "loop" back through the twisted splice thereby taking out the twist
If I understand correctly you are using the technique for making a locked Brummel when you do not have 2 free ends. There is no need for this, as you do have 2 free ends.

8. wrap the lines around the low friction ring and snug up to your liking
At this point follow my instructions in post # 43 that is reproduced below. You need to make sure the two lines are of equal length in the weave.
In the original post I instructed to form the weave then mark the spot to put the lock on both tails (this is where the base of the Diamond sits and creates a lock). Then unravel the weave, measure the 2 lengths marked and average them and mark this clearly.
The easier way is just to match the two tail ends if they were trimmed to be the same length after the eye was created.
This spot should be the same distance from the weave as the Brummel lock is on the other side.
This is where you place a temporary constrictor knot or tape when you have created the weave again and this marks the base of the Diamond. This ensures the two lines are tensioned equally in the weave.

9. tie a diamond knot,
10. check it goes around what you are planning, eg a stanchion
Unfortunately it is too late to make it bigger or smaller by shifting the position of the Diamond stopper. You need to undo the Brummel lock and make the distance between the base of the eye and the Brummel longer or shorter as necessary.
I know this sounds time consuming, but achieving a very snug fit requires trial and error. At least you can measure this distance and then reproduce this easily if LF rings on other stanchions are needed.

11. snug it up
12. snug it up some more.
Check the tails are of equal length when you have tensioned it as much as possible by hand. Then apply load using a winch to pretension it well. Leave sitting under load for 20-30 minutes. This is only really needed if the system is likely to get high shock loads when first used. In your application I do not think this will occur.

These were my original instructions:

Originally Posted by Seaworthy Lass

INSTRUCTIONS FOR THE DIAMOND SHORT STROP

Measurements are for 6 mm dyneema and a low friction ring with a 25 mm internal hole diameter.

Approx 120 cm of dyneema is needed (you can get away with a little less if your Diamond stopper tying skills are good and you will need a little more if they are weak).

Instructions for this are complicated if they are written so that someone with zero experience of making soft shackles could make one. It would take hours to describe this procedure well incorporating all the tips and photographing each step. I have started a couple of times, but am finding the task too daunting, so the following instructions assume reasonable soft shackle making knowledge:

Edited to add:
To maximise strength, it is very important that the load is distributed evenly, ie the two portions of line between the apex of the eye and the start of the diamond stopper are exactly the same length.
To help make the two lines in the weave the same length, use the technique described for the Bullseye loop strop before you start:
Wind your dyneema snuggly in the Bullseye pattern around your ring, as shown in post #14 & 15 as if you were making a loop strop. Read the instructions there on how tight to make it. Mark with a texta where it needs to be locked to maintain this. Unravel and measure between the marks. Average the two measurements. This is the distance you want to leave between the Brummel lock and the diamond stopper.

• Find the halfway mark and make an eye there, as for a soft shackle. Tape snuggly with blue tape to hold it in place
• 10 cm from the apex form a Brummel lock, making sure the lines are not twisted when you make the insertions. The dyneema has a flattened profile so it is easy to see if it is twisted. This distance is needed to allow easy opening of the eye. Make this distance longer if you want a longer strop.
Leaving a couple of strands between the lock insertions leaves room for equalisation of length under load.
This lock is required to hold the diamond weave in place below the LF ring (the diamond stopper does this on the other side).
Smooth the line from the apex to the Brummel out neatly. I would tape over the first insertion to keep all this together nicely.
Past the Brummel lock, with thin texta mark both legs the exact distance you decided on at the beginning.
• Create a plaited weave as shown below. Dyneema has a slightly flat profile. I would take a little effort and lay it flat the whole way, not rotating it around. It is probably not vital, but it all sits just beautifully at the end if you do this and load is distributed more evenly. After pretentioning, this pattern is maintained, so it seems favourable.

Instructions were continued in the next few posts:

• Form the Bullesye weave as was shown.
• Carefully match up your texta marks and tie a temporary constrictor knot tightly with whipping twine.
• Tie a Diamond stopper with the base at the constrictor knot and tighten as much as possible by hand with the help of a marlin spike to pull each strand snuggly.
• Cut off the constrictor knot.
• Pretension closed on a winch and leave to sit under load for half an hour. I understand this helps prevent failure if the stopper is subject to high shock loads before being being fully tightened.
• Trim the end of the stopper whatever length you are comfortable with. Commercial ones tend to be very short. I leave mine longer for safety.

Note the Brummel lock and base of the Diamond stopper are about equidistant from the LF ring. Also, the weave is not super tight around the ring. It does not need to be to hold the ring snuggly even if subjected to flogging, yet it enables the ring to still be removed if necessary:

[Amsteelbluez]

Originally Posted by Seaworthy Lass

If the ring doesn't need to be captured at all to prevent it dislodging, then the shortest arrangement is a soft shackle with twin legs and a Diamond stopper:




Or wrapping the shackle around the ring once will also shorten it:




One that just lightly captures the ring ends up just a bit longer (needn't be quite as long as below, this is just one I had lying around, not make specifically for the task):




On the general subject of soft shackles, there is no one best design. They all have advantages and drawbacks. Some can be made extra short, some are stronger, some have twin central legs and some have one central portion, some have a beautifully smooth symmetrical stopper as in the second photo above. The best type depends on what it is to be used for.

It is very useful learning to make several different types. They may look daunting, but basic ones are dead easy to make.
The Diamond knot used in the first photo above is just a Carrick bend with the ends swirling around it anticlockwise before being pushed out from bottom to top through the centre. A night practicing with a bit of spare cord while your hands are idle watching a movie and it can be then just about tied in your sleep. A simple shackle with twin legs and a Diamond stopper literally takes a few minutes to make, plus pretensioning time (they all need this).

If you have no interest learning to tie a symmetrical stopper, then check out Estarzinger's arrangement in his load testing document: http://www.bethandevans.com/load.htm.

If you have a bit of patience learn to tie a Button stopper. This is a beautiful stopper as it does not have ends poking out so it is smooth to handle and can easily be pushed through the noose one handed. This is useful. As with Estarzinger's stopper, the noose not the stopper then limits the shackle strength.
I have photographed instructions for making it and posted them in this thread:
https://www.cruisersforum.com/forums...ot-155591.html

The Diamond short strop is not a soft shackle and it tries to address a unique situation - when a short strop is needed and the low friction ring needs to be very snuggly captured.

I have started writing instructions, but it is a lengthy chore to explain well so will take some time. Not enough hours in the day even when cruising .

SWL

I am looking to make a couple soft shackles with 3/16 Amsteel Blue and a 14mm LFR. The user wants the shackke portion to be short, 2.5" length, without knot. Seems very short for 3/16? I have a 7/64 shackle at 3" and it fits real snug over my pinky.

You mentioned the right one for the eight application and some can be made extra short. Which one would that be? Does the ring come off easily or stay in place for good?

Thanks