Jordan Series Drogue in Dyneema

[seandepagnier]

I'm interested in rebuilding my JSD using dyneema instead of double braid nylon.


I currently have 60 cones on 5/8" double braid. It seems incredible that spectra of 5/16" is the same strength, so is spectra really 4 times stronger for the diameter?


In the interest of having minimum weight, I should be able to use 1/4" spectra for the first cones. What is the recommended load calculation for number of cones using spectra?


Can anyone recommend attachment points for use on a trimaran?

[BigBeakie]

Originally Posted by Fi2010

Your comment about shock loading only occurring with the JSD is inaccurate. We’ve made it obvious in numerous posts, articles, and YouTube videos that shock loading is the number one problem for all drag devices.

Please realize we’re trying to simplify things by avoiding getting too technical. This way everyone can more easily understand the problems and solutions. The Constant Rode Tension Methodology, for example, was purposely put together to be simple for sailors to remember. “Use weight placement, rode with less stretch, shorter rode lengths, motor or sail power to increase loading on rode, etc...” The Rode Tension solutions apply equally to all drag devices.

Cyclical or sudden shock loading eventually produces the same results. Sudden shock loading only causes breakage faster.

And yes, we have access to an experienced inventor of drag devices. He’s the one that figured out what the deployment problems were regarding the JSD, Para-Anchor, and Speed-Limiting drogue. It’s one of the reasons he works with NASA and our Navies amongst other organizations. His job is to figure out problems and find a solution to insure a successful mission. Not only to keep our astronauts and military safe, but to make sure sailors survive the storm; regardless of the product they choose to use.

What? You haven't addressed the point I was making, at all.

But thanks at least for confirming my suspicions....

[BigBeakie]

Originally Posted by Fi2010

Cruisers Forum has far more details related to all things cruising than Morganscloud and we don’t have to pay any fees. Morganscloud also admitted to accepting advertising dollars from JSD promoters. This might explain why information related to competing equipment like para-anchors and speed-limiting drogues are omitted.

At least on Cruisers Forum we can read differing opinions from novice to experienced sailors. We can occasionally receive an opinion from the manufacturer themselves. Manufacturers should be the most experienced in understanding how to use their equipment. Not just drag device manufacturers, but all manufacturers.

The knot setup used to form the JSD bridle has been suggested by the JSD suppliers since the beginning. Are you sure JSD suppliers didn’t figure out there was a problem with their knot/bridle recommendation until 2018?

If what you’re saying is accurate, then technically a voluntary recall on all JSDs equipped with a bridle should be considered. Bridles put together by the supplier. We’ve only heard of one speed-limiting drogue that ever had a voluntary product recall. The company either refunded money or replaced the drogue.

I can't comment on the relative worth of morganscloud.com versus Cruisers Forum as a general opinion, unlike the Oracle level wisdom of yourself, but I can say it is thorough, organised, continually updated, covers many topics not covered here that are important to me, and costs bugger all.

Likewise I can't comment on what should happen if there is a problem with how JSDs are constructed. I have no idea on that. I only know that Goodall's incident highlighted a possible issue with a knot being the weakest link, and the vendor has improved his product.

However, I can comment on you casting aspersions on the integrity of the folks that run morganscloud.com, and offer my opinion that if there is any bias demonstrated that is commercially driven, I know which author shows that more clearly....... and it ain't the folks at morganscloud.com

You seem to be a hyper competitive individual, ever ready to bag the competition, and you seem to be pissed that the community at morganscloud
probably think Don Jordans JSD is better than your product offering, and don't want your advertising dollars. If so, just get over it, it's becoming irksome.

[fxykty]

Originally Posted by seandepagnier

I'm interested in rebuilding my JSD using dyneema instead of double braid nylon.


I currently have 60 cones on 5/8" double braid. It seems incredible that spectra of 5/16" is the same strength, so is spectra really 4 times stronger for the diameter?


In the interest of having minimum weight, I should be able to use 1/4" spectra for the first cones. What is the recommended load calculation for number of cones using spectra?


Can anyone recommend attachment points for use on a trimaran?

We bought only cones from OceanBrake a few years before they started making them in Dyneema. They had the specifications of their double braid polyester rodes listed on their site, so we just used the breaking strength equivalents when choosing our Acera sizes.

With 165 cones (26 leader, 57 middle, 82 tail), the line sizes for our bridles and leader are 12mm Acera instead of 22mm double braid, 10mm Acera middle instead of 18mm double braid, and 8mm Acera tail instead of 14mm double braid.

For attachment spots on a trimaran, I would assume either on the inside corner of each rear beam/ama, or at the stern outside end of each ama. If you want to ensure there’s no interference by the ama sterns when yawing, then the stern location is safer.

[Fi2010]

Too busy to worry about bagging anything. However, never too busy to set the record straight against misinformation. It’s why we appreciate Cruisers Forum.

Not at all concerned about any product being better than what we manufacture. We’re barely keeping up with production as it is. If someone does comes up with a better mouse trap, we’ll be glad to build it for them.

[seandepagnier]

Originally Posted by fxykty

We bought only cones from OceanBrake a few years before they started making them in Dyneema. They had the specifications of their double braid polyester rodes listed on their site, so we just used the breaking strength equivalents when choosing our Acera sizes.

Do you mean they make the cones from dyneema now too, or just the rode?

With 165 cones (26 leader, 57 middle, 82 tail), the line sizes for our bridles and leader are 12mm Acera instead of 22mm double braid, 10mm Acera middle instead of 18mm double braid, and 8mm Acera tail instead of 14mm double braid.

Since I have only 60 cones (boat weight is 2 ton) I am looking at using 8mm, but I would like to use 6mm for the last 30 cones... So I'm wondering if this works or if it's a bad idea to go too small. Could you instead cut strands so go from 12 braid to 11 braid down to say 8 braid without needing to splice while also getting a more uniform taper?

Did you use locking brummel splice?

What is the best way to attach the cones to 12 braid? each cone has 6 webbing, so run them through the 12 braid and tie figure 8? Run under 2 or 3 or 4 strands?

[fxykty]

Originally Posted by seandepagnier

Do you mean they make the cones from dyneema now too, or just the rode?
Since I have only 60 cones (boat weight is 2 ton) I am looking at using 8mm, but I would like to use 6mm for the last 30 cones... So I'm wondering if this works or if it's a bad idea to go too small. Could you instead cut strands so go from 12 braid to 11 braid down to say 8 braid without needing to splice while also getting a more uniform taper?

Did you use locking brummel splice?

What is the best way to attach the cones to 12 braid? each cone has 6 webbing, so run them through the 12 braid and tie figure 8? Run under 2 or 3 or 4 strands?

No, the cones are from woven polyester AFAIK. The new cones for Dyneema rodes are of a thicker material and use wider webbing tapes. This photo shows both:



Regarding tapering, I would girth hitch two eye splices together with one being the thicker and one being the thinner rode. I’m not sure about strength but removing strands to make it lighter seems pretty dangerous to me. Here’s how we connected the different sections together:



Yes, locking Brummel eye splices throughout. I’ve seen some comments that the tail can get loose so I may whip the tail entry.

The way to attach the webbing to double braid (according to OceanBrake) is to tuck the webbing under the cover, bring it back out and figure eight as a stopper. With single braid we felt that once through was not enough, so we went once through then back again, then figure eight as stopper. Insert each of the three tapes 4 strands apart and for each count 4 strands forward in one direction and 2 strands the other direction, then over the two strands forming a V, then through again 4 strands forward in one direction and two the other direction. Not a great description, sorry. This photo shows the tapes when done:



Note, I’m using ‘Dyneema’ as short hand for UHMWPE line, known commercially as Dyneema and Spectra. We use Acera Amundsen, made by Timm’s Ropes and available through Greenline Fishing Supplies. It’s yellow!

[Benz]

^^^By all means whip the tail entry.

[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?

[BigBeakie]

Can I ask how you came up with 60 cones for your 2 ton tri?

Oceanbrake show recommended 130 cones for a 3.5 ton multihull, so maybe 60 cones is a bit under spec?

[seandepagnier]

Originally Posted by BigBeakie

Can I ask how you came up with 60 cones for your 2 ton tri?

Oceanbrake show recommended 130 cones for a 3.5 ton multihull, so maybe 60 cones is a bit under spec?

I got these years ago for a different boat (monohull), and it was all I could afford at the time. I also have a regular drogue (about 2ft diameter) I can put on the end...

Is there any consensus for weight on the end and if you can also use an anchor rather than all chain to get the sufficient weight?

Originally Posted by oceanbrake

130 6,600 lbs $1,312.20
140 12,000 lbs $1,386.90
150 18,000 lbs $1,497.00
155 30,000 lbs $1,639.40
160 33,000 lbs $1,706.30
165 40,000 lbs $1,773.30
170 50,000 lbs $1,840.20

130 vs 140 at double the displacement seems a bit arbitrary. I'm no expert on the drogue calculations but I wonder if they are based also on them selling more? Extrapolating from this table I would need 120 cones, where a boat which weighs 5x more would use 150 cones.

I got these for I think $3.75 each, so oceanbrake seems a bit expensive.

[BigBeakie]

Originally Posted by seandepagnier

I got these years ago for a different boat (monohull), and it was all I could afford at the time. I also have a regular drogue (about 2ft diameter) I can put on the end...

Is there any consensus for weight on the end and if you can also use an anchor rather than all chain to get the sufficient weight?
130 vs 140 at double the displacement seems a bit arbitrary. I'm no expert on the drogue calculations but I wonder if they are based also on them selling more? Extrapolating from this table I would need 120 cones, where a boat which weighs 5x more would use 150 cones.

I got these for I think $3.75 each, so oceanbrake seems a bit expensive.

The required weight also comes from Don Jordon's calculations and testing, and minimum I have seen is 15 to 20 kg. I've been looking for a big mushroom anchor to use, but can't find any here in Oz. They used to be common for dinghy anchors, decades ago.

Yes, it is obviously not an arithmetic relationship, boat mass to number of cones. As the boat mass goes up, so does the boat mass per cone. And big difference between monohulls vs multihulls, isn't it? That would be related to how easily a multi takes off down a wave face and gets quickly up to high speed, I guess.

[pk999]

Hi all,

I too noted the larger number of cones recommended for mulithull vessel weight vs monohulls, and had assumed similar logic in faster rate of acceleration of the multihull = speed x mass needing to be stopped.

If this is so, is there any difference between stopping forces (number of cones required) for a similar weight monohull using Dyneema vs Polyester braids for the JSD? I had previously assumed that a more stretchy braid would result in gentler shock loadings being applied to the bridle/boat attachment points in the event of large breaking wave strike. But if the more stretchy JSD allows the mass of the boat to accelerate to a higher speed before starting to stop it, is this a false assumption?

[BigBeakie]

Yes I believe it is a false assumption. Here's why. The JSD with enough weight on the end hangs down in the water column in a curve. There is a forward vector to the pull of the boat as a wave pushes the boat and then as the boat begins to accelerate, the JSD cones that are "hanging down" are pulled up in the water column and more cones are being pulled along in the horizontal direction, which increases the drag resistance in response to the increased boat speed. The load comes on progressively, not as a shock load. So stronger, non-stretchy line is better.

[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.