Jordan Series Drogue in Dyneema

[BigBeakie]

Originally Posted by Fi2010

So glad you’re finally recommending the original weight recommended for Don Jordon’s product. Unfortunately, most suppliers are still pushing for the use of 10 to 15 lbs. (4.5 to 6.8 kg) of weight, instead of the original 35 to 50 lbs. (15.9 to 23 kg) of weight necessary to make the JSD perform better.

The curve is not as relevant as using the proper weight placement to reduce shock loading. This rule applies to all of the drag devices. Para-Anchors and Speed-Limiting drogues only require less weight than the JSD.

The so called load comes on progressively with the JSD is the same with para-anchors and speed-limiting drogues. It’s all about the rode and weight, not the cones. However, the more cones you use the more you will definitely feel the drag. This impacts performance.

“The stronger, non-stretchy line is better” was first published by our company, later confirmed through NASA testing. NASA tested several drogues, para-anchors and deployment rode configurations to determine what would best stabilize a 20,000 lb capsule.

What makes stabilizing a capsule challenging is the vessel has a lot of windage, no keel, and no power or sail to help balance out the craft. At least sail boats have more options to help the drag device do its job. In the end, NASA determined the para-anchor and rode with no stretch did the best job in stabilizing their floating craft.

Well you never miss an opportunity to plug your product, do you? It seems it was always you guys who were the first with every good idea. Is this supposed to establish credibility, or something?

What do you mean you're glad I'm finally recommending the right weight? Is that supposed to mean I've said anything different in the past? Can you cite one example of me doing that?

While you're at it, can you cite the dates where you first recommended dyneema rode instead of a more stretchy material compared to others, that show you were the first? I doubt that is the case.

And I'm only aware of Ace Sailmakers in the US and Oceanbrake in the UK that make JSDs from scratch, and I don't recall any info on Oceanbrakes site about the specific weight to use. So who exactly are the "most suppliers" that are "pushing" using less weight???
Again, can you cite examples?

[fxykty]

Tail weight for a JSD is still an emerging science, particularly when substituting sinking and larger polyester double braid rodes with floating and smaller Dyneema rodes.

For our JSD with 165 cones the recommended weight for double braid is 11kg. I asked OceanBrake and they suggested 22kg weight for a Dyneema rode. I have yet to test our completed JSD, but will report back when we do.

[Fi2010]

We’re using generic names to describe the various drag devices. We’re not providing any links or brand names. The opposite is true with you. You use specific brand names and mention specific companies and websites.

Our intent is to provide information omitted about drag devices on any platform…whether accidental or intentional. Our posts on Cruisers Forum make it clear that we are providing solutions that work for the JSD, Para-Anchor, and Speed-Limiting drogues. We frequently make statements like - “this is a problem for all of the drag devices” or “here’s the solution or solutions to make them perform better”.

The answers to your questions are actually posted on this forum - although scattered in several threads. Answers are also located on our website, and videos, including comments from JSD suppliers not using an alias. You can review the published report from NASA on either their website or one of their associates’ websites. It might explain why they prefer the para-anchor over the storm drogues.

[Fi2010]

Very happy to hear about the increased weight recommendations for the JSD.

[fxykty]

Originally Posted by seandepagnier

Thanks for the reply.

I feel like instead of girth hitch, it should just use thimbles interlocked. The girth hitch seems like a weak point, but how weak I am not sure.


Wouldn't it be stronger, simpler and ligher to brummel splice the two pieces together end to end? Is this a problem for different sized lines? I had assumed this was the best solution.


As for the bridal. Do you use eye splices as well all connected to a shackle or is there a good way to make a "Y" splice?

Someone else already commented that girth hitches make little reduction in strength and are fine to use, especially when using materials where the strength is more than needed. I prefer to have everything modular so that future replacements of one or more of the components are a bit simpler.

I like to reduce connection links as much as possible, hence the use of girth hitches to connect the two bridle lines to the leader. The leader eye passes through both bridle eyes in a single pass, then the entire JSD rode passes through that eye to complete the hitch.





(Sorry for the busy background)

The system I’ve used allows for complete unloading of either bridle without any issues.

Girth hitches loose a little strength, but not much and less risk of failure than using a separate shackle to connect the three eyes.

I considered making an eye in the middle of a single (double length) bridle line, but considered that there would be unequal loading (on yaws) on each bridle. That would be a bit of a risk in a single eye.

We’re fortunate that our boat has full length aluminium toe rails along the hull deck joints. After checking with an engineer we beefed up the last 1.2m of each toe rail with a flanged hull plate and added through-bolted u-bolts. Then a high strength soft shackle on both sides to connect to the bridle eye. As there is some hull behind the u-bolt, I made very long eyes and covered with Dyneema chafe guard.





We’re planning to replace the wire lifelines with Dyneema and may look at terminating them further forward so they’re not in the way.

Comments welcome, especially if you think I’ve done something wrong.

[sailingharry]

You know, I have to say that one of the more irritating things about CF is vendors like Fi2010 (frankly, I can't tell just what his product is, he has hidden is relationship so thoroughly), and the war between Rocna and Spade, that relentlessly throw mud and insult each other while touting their products as the best.


I recommend you go read some posts by Tellie. Or come to the Saga owners forum and see the posts by Doug of Klacko Marine -- his company built all the stainless on the Saga, and he is a friendly and supportive contributor to the forum WITHOUT BASHING OR BOASTING. You can be a valued contributor without being an intolerable jerk.


And as a final request -- can you PLEASE go sell your snake oil elsewhere? This thread was really enjoyable.

[BigBeakie]

Do you know the SWL of the U bolts? Are they 10mm dia.?

[fxykty]

Originally Posted by BigBeakie

Do you know the SWL of the U bolts? Are they 10mm dia.?

14mm 316

[Benz]

Originally Posted by fxykty

Someone else already commented that girth hitches make little reduction in strength and are fine to use, especially when using materials where the strength is more than needed. I prefer to have everything modular so that future replacements of one or more of the components are a bit simpler.

I like to reduce connection links as much as possible, hence the use of girth hitches to connect the two bridle lines to the leader. The leader eye passes through both bridle eyes in a single pass, then the entire JSD rode passes through that eye to complete the hitch.

Attachment 230701

Attachment 230702

(Sorry for the busy background)

The system I’ve used allows for complete unloading of either bridle without any issues.

Girth hitches loose a little strength, but not much and less risk of failure than using a separate shackle to connect the three eyes.

I considered making an eye in the middle of a single (double length) bridle line, but considered that there would be unequal loading (on yaws) on each bridle. That would be a bit of a risk in a single eye.

We’re fortunate that our boat has full length aluminium toe rails along the hull deck joints. After checking with an engineer we beefed up the last 1.2m of each toe rail with a flanged hull plate and added through-bolted u-bolts. Then a high strength soft shackle on both sides to connect to the bridle eye. As there is some hull behind the u-bolt, I made very long eyes and covered with Dyneema chafe guard.

Attachment 230705

Attachment 230706

We’re planning to replace the wire lifelines with Dyneema and may look at terminating them further forward so they’re not in the way.

Comments welcome, especially if you think I’ve done something wrong.

Your pictures bring up two concerns to me: First, when you load a girth hitch up enough, it can bind and become impossible to undo. If I want to undo a knot or bend that will be heavily loaded, I put a fid though it. Just a piece of rod or dowel will do, which you can push out when you want to undo the hitch, and gives you the necessary slack to do so ( to undo so? ).
You'll have to find a way to keep it from sliding out when it's not tensioned (tape? twine? velcro?) but it will make your hitch able to be undone.
Second, the pull on the U-bolts is not where U-bolts were designed for, which is with both legs evenly in tension, rather than one in sheer and the other lazy. It's probably fine, and hopefully your engineer accounted for that, but it does catch my eye.

[BigBeakie]

I think the U-bolts might be the weak link in your system. They certainly are nice beefy ones, but still, here are my thoughts.

We've spec'd our JSD attachments, each of them, to hold 70% of our boats full cruising displacement, as per Jordon's engineering analysis. Apparently he was a pretty good engineer, and I have not seen any data to the contrary. The emphasis on having each attachment hold that 70% of displacement ( in a worst case breaking wave scenario under storm conditions) is if/when the boat yaws down a wave, most of the load goes to one attachment point from one of the bridle arms.

I'm guessing your cruising displacement is about 8 to 10 tons? So each attachment needs to hold about 7 tons, worst case scenario?

I think the breaking load of your U bolt is about 6 tons from just a quick look >https://hayn.com/marine/misc/ubolts.html

But as mentioned above, the issue is more the load path and how the fitting handles it under cyclic loading. The breaking strength spec would be for a U bolt with the pull straight up I think, or at least shared between the 2 legs of the U bolt. In this case the pull will be at right angles to the leg, and only on one leg. So maybe the spec breaking strength value could be less than half???

I had a similar high load application on our boat and was going to use a U bolt but a marine engineer persuaded me to use a high spec padeye instead, because of the side pull loading.

These are very nice Duplex steel ones from Wichard with 11 ton breaking strength in the side pull direction. Plus you're using 4 x M8 bolts with backing plate to share load, instead of effectively 1 leg of the U bolt.

https://www.wichard.com.au/wichard-diamond-padeyes/

Hope that helps.

[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.

[At Peace]

Originally Posted by sailingharry

You know, I have to say that one of the more irritating things about CF is vendors like Fi2010 (frankly, I can't tell just what his product is, he has hidden is relationship so thoroughly), and the war between Rocna and Spade, that relentlessly throw mud and insult each other while touting their products as the best.


I recommend you go read some posts by Tellie. Or come to the Saga owners forum and see the posts by Doug of Klacko Marine -- his company built all the stainless on the Saga, and he is a friendly and supportive contributor to the forum WITHOUT BASHING OR BOASTING. You can be a valued contributor without being an intolerable jerk.


And as a final request -- can you PLEASE go sell your snake oil elsewhere? This thread was really enjoyable.

Hahaha.....yeah, I'm thinking just about everyone is tired of hearing from Fi2010. I've looked into his claims (wish I could get the time spent back) and find it mostly a huge stretch of the truth.
He does have a product that he's trying to sell, but in my thinking, it's hard to argue against actual real world use.

[oldbilbo]

I'm looking to secure JSD bridles to the loop-splice at the front end of a JSD - all using UHMW single-braid, all abrasion-sheathed - and wonder if there's 'knowledge/opinion' about the relative strength losses in the three configurations...


A: as in #155 above - thanks, fxykty.






B: as in...






C: as in...

[Breaking Waves]

Originally Posted by oldbilbo

I'm looking to secure JSD bridles to the loop-splice at the front end of a JSD - all using UHMW single-braid, all abrasion-sheathed - and wonder if there's 'knowledge/opinion' about the relative strength losses in the three configurations...

Bilbo,

Those are nice thimbles but used in that way they look to have relatively sharp 90 edges bearing on the cow hitch - that is a problem - would likely be way weaker at that corner than option (a).

Option (a) is somewhere in the 85-95% strength range (near 95% on a short-term one-off load test but lower in long-term multiple high load use due to internal compression weakness). There are other connection approaches that are 100%, but this 5-15% may not matter if you may already be oversized or if there are other 85% nodes in the system.

[fxykty]

Originally Posted by Breaking Waves

Bilbo,

Those are nice thimbles but used in that way they look to have relatively sharp 90 edges bearing on the cow hitch - that is a problem - would likely be way weaker at that corner than option (a).

Option (a) is somewhere in the 85-95% strength range (near 95% on a short-term one-off load test but lower in long-term multiple high load use due to internal compression weakness). There are other connection approaches that are 100%, but this 5-15% may not matter if you may already be oversized or if there are other 85% nodes in the system.

BW, I think you mentioned earlier that the addition of a dowel or dog bone into the connection I’m using (option a) would tidy up the fibre paths and increase the strength. Is that a correct interpretation?

I’m thinking something like this, with A being better and the loops not connected to each other. How does one ensure the dog bone doesn’t fall out when there is no tension?


Alternative B, the loops are still girth hitched together and still are compressing each other, but have wider turns.


These drawings show the two bridle legs connected to the leader section and they are all 12mm Acera Amundsen with Dyneema chafe covers. I would also do the same with the subsequent 12mm to 10mm eye connection and the 10mm to 8mm eye connection.

What do you think?