Jordan Series Drogue in Dyneema

[Fi2010]

You're making everything way too complicated. What's worse is some of the recommendations provided are likely to cause even more problems than already reported.

Remember the old adage...keep it simple.

[BigBeakie]

Ok, I'll bite. What's your solution, Fi2010?

[Fi2010]

The context of your question is insincere. It’s clear from your past behavior you’re interested in promoting what you believe in without authentic interest in competing opinions.

[sailingharry]

oldbilbo,


A small detour in a thread that has lost the entire map.....Your diagram shows the Figure 8 Loop as a very good knot, a fact that I've heard enough that I'm starting to believe it. At a few months shy of 60, and sailing all my life, I've never seen it recommended or used in the real world. What am I missing? Why is this knot, easier and quicker to tie than a bowline, not more common? I do realize it is almost impossible to tie AROUND something (a jib clew, for instance), but where a loop can be simply tied (to drop over a piling, for instance), why is this not the "gold standard?" Perhaps it's hard to untie?



Harry

Originally Posted by oldbilbo

Just a reminder from Marlow Ropes to consider carefully the use of ANY knots in your JSD rig.... We know what happens to Breaking Load.

[Benz]

Originally Posted by sailingharry

oldbilbo,


A small detour in a thread that has lost the entire map.....Your diagram shows the Figure 8 Loop as a very good knot, a fact that I've heard enough that I'm starting to believe it. At a few months shy of 60, and sailing all my life, I've never seen it recommended or used in the real world. What am I missing? Why is this knot, easier and quicker to tie than a bowline, not more common? I do realize it is almost impossible to tie AROUND something (a jib clew, for instance), but where a loop can be simply tied (to drop over a piling, for instance), why is this not the "gold standard?" Perhaps it's hard to untie?



Harry

It can jam up tight when heavily loaded, and become impossible to untie. It's popular among rockclimbers because it looks very secure, and because they rarely load it enough to make it jam. But a bowline is better in most situations.

[oldbilbo]

I'll reply to 'sailingharry'...

The graphic was taken from Marlow Ropes' website, and its purpose was - as I stated - as a reminder to 'consider carefully'.


I've used a Figure-8 Loop as shown since my early rockclimbing/instructing days over 60 years ago. That suggests I'm 'senior' to you! One uses a locking snaplink/karabiner/mousqueton to secure the climbing rope to one's harness. If it looks right, it is right.... and one can see a student's is OK from a distance. It's one of half-a-dozen knots/bends I use all the time.

In the context of this thread, I hold it important to bear in mind that EVERY knot/bend in the construction of a JSD weakens it to some extent. Some rigs have wholly superfluous 'Double Figure-8 Loops' tied in them ( I have posted pics of such laid out on a pontoon ) and they must reduce the strength of those rigs substantially.


Whenever I use a bowline, I always use a half-hitch in the short end to reduce the tendency for the bend to loosen itself.

[Breaking Waves]

Originally Posted by sailingharry

Figure 8 Loop . . . . bowline,

Well - you already nailed the two reasons the bowline is used - easier to tie thru a closed ring/fitting - and easier to untie after a big load.

The figure 8 is the gold standard for climbing - in large part not because of strength but rather because it is easier to inspect for proper construction and harder to screw up than a bowline.

Honestly, strength is an overrated metric for comparing knots. 99% of the time our ropes have plenty of strength and the differences between the various knot options is unimportant.

In high modulus rope, on a highly engineered system, the strength differences become more relevant . . but then you pretty much use splices. So, exactly the application the thread is discussing - splices not knots. Chafe and knot strength reduction and cone shredding are the only major failure modes in actual practice - a system should be designed to very definitively avoid those.

[oldbilbo]

I'm glad we're all in agreement, and can now move on.

[At Peace]

Originally Posted by oldbilbo

I'm glad we're all in agreement, and can now move on.

EXACTLY! While both have their purpose and reason, neither should be used in a Jordan Series Drogue. Splices...... Splices are the way to go! Maybe you can continue you discussion about knots in a thread for "knots".

[oldbilbo]

It's a while since I've looked in here. 'Covid isolation', I suppose...

However, I'm working on a new Jordan Series Drogue in all-UHDPE.... or Dyneema. Each of the bridle-legs' ends is terminated in a '72 x diameter bury' eyesplice ( as recommended ), with antichafe tubing fitted, and each has a tubular s/s thimble for best D:d bend ratio.







The cord whipping is 'belt and braces' antichafe. I've also 'square sewed' through the bury. Same setup with the ends of the continuous Dyneema rode.


I could attach the rode to the bridle-legs using a single large steel shackle ( or two of them ) but am considering a very robust 'soft shackle' linking the 3 tubular thimbles - rather like the 'soft shackle' illustrated here. This could be looped once through the trio of thimbles, or twice - to double the Break Load.






I'm wondering about the 'multiplication factors' to apply. I'm aware that a single loop-strop, long-spliced with an appropriate bury, gains about 1.6 x single line nominal Min Break Load.


What does the congregation think about pros/contras in the above arrangement?

[Seaworthy Lass]

Originally Posted by oldbilbo

It's a while since I've looked in here. 'Covid isolation', I suppose...

However, I'm working on a new Jordan Series Drogue in all-UHDPE.... or Dyneema. Each of the bridle-legs' ends is terminated in a '72 x diameter bury' eyesplice ( as recommended ), with antichafe tubing fitted, and each has a tubular s/s thimble for best D:d bend ratio.

The cord whipping is 'belt and braces' antichafe. I've also 'square sewed' through the bury. Same setup with the ends of the continuous Dyneema rode.

I could attach the rode to the bridle-legs using a single large steel shackle ( or two of them ) but am considering a very robust 'soft shackle' linking the 3 tubular thimbles - rather like the 'soft shackle' illustrated here. This could be looped once through the trio of thimbles, or twice - to double the Break Load.

I'm wondering about the 'multiplication factors' to apply. I'm aware that a single loop-strop, long-spliced with an appropriate bury, gains about 1.6 x single line nominal Min Break Load.


What does the congregation think about pros/contras in the above arrangement?

Hi Oldbilbo

When making a series drogue from UHMWPE I based decisions I made on standard best techniques for working with this material, lots of feedback from other members (some highly experienced) here on CF, plus on experiences reported by other users.

This was the long thread discussing construction a couple of years ago:
https://www.cruisersforum.com/forums...es-216499.html

Thimbles generally seem not recommended due to the risk of chafe and possibility of snagging of cones during deployment. There seems no benefit in using these.

Regarding the 2 joins between the 3 main segments, I used strop bends. Losses in strength when using these (and from less than 1:1 bend radii) are small and need to be viewed in conjunction with other losses occurring that are not cumulative (eg when the straps of the cones pass through the line). Other alternatives for these two joins are splicing the eyes together or possibly just splicing the lines together.

I, too, used long bury eye splices with 72 x bury of the tails and “square” lock stitching, but used a strand of the UHMWPE for the stitching, as recommended by the manufacturer. What type of cord did you use for this?

I would personally not use a soft shackle at the join between the bridle and legs. Even the smallest chance of the shackle opening is not acceptable in this application. A loop could be used here, but movement of the legs will occur. I opted for a “modified” strop bend as shown below, as I was concerned (rightly or wrongly) about chafe at this join when the load moves between bridle legs.

[StoneCrab]

Originally Posted by fxykty

Received a few new cones from Ocean Brake. They also sent a slightly longer bent wire ‘Tape Insertion Tool’.

The new cones are made of a thicker fabric (feels more like polyester, while the original cones are vinyl I think), thicker bindings, and much thicker tapes. Here are the new and original cones.

Attachment 216782

I suppose the change in cone design is due to reports of cone damage, though I haven’t heard that about the original Ocean Brake cones.

I believe OceanBrake warranties their cones, replacing them if they fray and go bad. They use a very thick material that is only sold in England. I spoke to them before committing to building mine. I went with the heaviest sail cloth I could buy, but the cloth that they use is thicker and more specific to the task.

My conclusion when I was done was that I didn't really save any money and worked my but off putting in many many hours. I honestly don't see how he sells his JSD's at the price he does.

My recommendation to anyone asking is to buy one rather than make it..... unless you just enjoy repetitive tasks. Sure the joy of building it is a benefit but man that is a load of work. Given the pandemic lockdown, I needed a project.

[Fi2010]

Importing from Asia or by purchasing seconds fabrics is how some companies save money. Fabrics listed under the seconds category have various flaws, but are very cheap to purchase.

We’ve towed equipment behind work boats to test the strength of seconds fabrics. Sometimes the drag device holds up sometimes it disintegrates immediately. Don’t expect the company selling the drag device to be forthcoming about the purchasing of parts or equipment for resale.

Kudos to the American company that admitted to using seconds fabric and the other one for not denying they actually import their cones for resale.

In some countries, a company can import their drag device and claim to be a manufacturer. As long as they place their logo on the equipment. This is surprisingly legal.

In the US we are required by law to be forthcoming with made in USA or list where the items are actually manufactured. We had to fill out lengthy contracts to supply NASA and the USCG to confirm where all of our parts are purchased and where we build the equipment. Lie to these organizations and you go to prison.

We assume the UK has similar laws as the USA.

[BigBeakie]

Oldbilbo,

I can understand your use of the gusseted enclosed thimbles for the bridle ends that attach to the boat if, for example, you need to use a shackle to attach to a hard point ( that is my situation as well), but why did you use them on the other ends of the bridle that attaches to the JSD main line first section?
Could you cow hitch the 2 bridle ends if they were long bury eye splices with the long bury eye splice in the JSD first section?

[oldbilbo]

Essentially, as answer to BigBeakie's question, let me make it 'plain as day' that I don't KNOW answers. I do, however, read extensively, question and query.... and look for solid consensus on issues that matter. Where there is something other, I dig deeper and wider.... especially where a 'confident assertion' somewhere seems counter-intuitive.

There's a lot of 'confident assertions' swirling around the JSD discussions, and what is offered as evidence often turns out to be a re-statement of someone else's unsupported opinion. Some opinions are well worthy of attention - and I do pay heed to those.

Take just one example ( but not too far! ) the assertion that the use of s/steel thimbles in the eye-splices of a JSD assembly is damaging and to be avoided. I haven't found 'evidence' of this - merely some supposition.

OTOH, I'm aware that the use of thimbles is commonplace - standard practice - in many industries where research has led to the establishment of IS Standards of Practice. I'm also aware that fibre ropes ( e.g HMWPE and steel ) risk serious damage if an adequate Bend Radius is not maintained, and that many knots/bends will not maintain an adequate D:d/Bend Radius, with consequent unknown loss of strength in the assembly.

I'm trying to ensure that I don't throw away much of the inherent and available strength of some superb products, through my ignorance. That's why I'm asking several of the principal rope manufacturers for their views. If a consensus emerges from their answers, I'm likely to incorporate that into the kit I will carry.

I'm not yet persuaded that the use of 'cow hitches' or 'doubled strop bends' achieves all the strength to be had from the use of long-bury eye splices in single-braid dyneema. I am, however, persuaded that some people have simply said "There. That ought to be enough..."


For the moment, that's as far as I'm willing to stick my neck out.