3 strand polyester for a Jordan Series Drogue?

[Neeves]

A reason for not using a stretchy line, and stretchy does not necessarily mean nylon, but something with less stretch, is that the cones nearest the vessel can suffer damage. To my mind this suggests the cones nearest the vessel are doing their job, doing that job preferentially over the cones further away and instead of damning the line, without thought, is a reason to look at how this 'failure' might be better used - one example being stronger cones nearest the vessel

The other thought is a hybrid line - something with stretch to take the snatch loads and then attach that section to a tail of dyneema to reduce weight.


The figures being quoted underline - you really need to look at the chain plates if you are going to deploy a drogue. You cannot have a drogue and ignore all the consequences. Thinwater contributed to a thread on chain plates, somewhere - I don't recall where, but it would be CF or here, Try searching with 'chain plates' and 'drogues'

Jonathan

 

[pandos]

Victor Shane's Drag Device Data Base | Using Parachutes, Sea Anchors and Drogues to Cope with Heavy Weather – Over 130 Documented Case Histories

Here is a series of real life stories of drogue use. Including one from a guy that used a JSD and a homemade device in the same storm...

 

[zoidberg]

There's actually quite a lot online about Jordan Series Drogues. One needs to do the websearching, and following the threads, but here's a good place to start:
AAC real world JSD deployment

Another source is 'The Drag Device Database.' ( Edit: see post above for link )

There are those who continue to promote other designs, but most find the arguments that engineer Don Jordan made to be conclusive. He used materials that were readily available to him, and his intention - following the Fastnet '79 Disaster - was 'proof of concept'. He left it to others to manufacture and market the things; some made improvements as better materials emerged. Some didn't.

There are vastly-experienced round-the-world sailors who won't go to sea without one e.g. Roger Taylor, Jean Socrates, and Susie Goodall - who's having a new one. They are referenced in the AAC pages, in Cruising Forum and Sailing Anarchy.

Part of the comprehension difficulties come from differing perceptions of what is needed, and when. Consider NOT a large sea with a bit of breaking crest that foams up around and past; instead consider a very steep, violent sea with a breaking JETTING crest that slams hard into the boat breaking unreinforced duckboards, and downflood.

Consider carefully the information here - Jordan Series Drogue - Considerations. Many would take the 'displacement' figure to be that shown in one's vessel handbook, and choose the other guidance accordingly. However, one should better consider the LADEN displacement, which is likely to be several tons heavier.
Does that matter? Certainly! You don't want a drogue-system that is capable of stopping just 3/4 of your boat's laden weight, for that risks it breaking when put to the greatest test. Given the advances in ropes/materials techology since Jordan's day, there really is little excuse for not going up a grade in strength.

Some users have found their ripstop nylon fabric cones have frayed in extended use, so are replacing them with new, stronger sailcloth. Others have experienced partial failures of 'open ended' steel thimbles , and are refitting with 'closed-ended thimbles'.

Others have experimented, with the help of rope manufacturers, with the optimum form of eye splice. Not all splices are good enough....

There's lots to research and, as everything else on here, a lot of chaff needs to be winnowed to separate out the wheat.

 

[Neeves]

Zoidberg

A nice balanced summary.

In terms of vessel weight - remember the crew and that you might be carrying wet sails. If full of fuel and water - (for us) that adds 600kg (in tanks - excludes any jerry cans) and those 2 items add 10% to weight alone. I hestitate to mention your anchor chain

Jonathan

 

[Roberto]

Some users have found their ripstop nylon fabric cones have frayed in extended use, so are replacing them with new, stronger sailcloth.

picture of a commercial JSD taken from Flying Fish; well what's left of a JSD. Not sure what type of cloth it is, being white colour more likely normal dacron than ripstop nylon?



Another case, this boat survived the 2017 Ostar (IIRC 5 boats were abandoned), Keith's Harmonii arrived in Horta in these conditions (he said the boat was "immaculate" at the start), sustained 70kt, among the damages he used a JSD but the farther half parted away, all the cones of remaining line were broken.
Some pictures:
OSTAR - Barca superstite a Horta
As a curiosity, the rust on the hull came frome the broken sat antenna, the power cable got in contact with metal and stanchions gantry lifelines etc all went live.

 

[geem]

A reason for not using a stretchy line, and stretchy does not necessarily mean nylon, but something with less stretch, is that the cones nearest the vessel can suffer damage. To my mind this suggests the cones nearest the vessel are doing their job, doing that job preferentially over the cones further away and instead of damning the line, without thought, is a reason to look at how this 'failure' might be better used - one example being stronger cones nearest the vessel

The other thought is a hybrid line - something with stretch to take the snatch loads and then attach that section to a tail of dyneema to reduce weight.


The figures being quoted underline - you really need to look at the chain plates if you are going to deploy a drogue. You cannot have a drogue and ignore all the consequences. Thinwater contributed to a thread on chain plates, somewhere - I don't recall where, but it would be CF or here, Try searching with 'chain plates' and 'drogues'

Jonathan

We have a JSD. It has 156 mini parachutes. The line is in two halves. The line nearest the boat is a lot thicker than the line at the end. I guess this has two purposes. You dont need such heavy line near the end of the JSD as there will be less load. The thicker
line near the boat will also stretch less. Ours is braid on braid but I dont know if its nylon. I had assumed it was.
Since the JSD must be in constant tension when deployed I wouldnt have thought stretch was such a big issue. All 156 parachute will exert a load assuming you have wind pushing the boat along. A large following wave will load up the JSD more and maybe stretch the line more but does that matter?

 

[zoidberg]

Geem,,,,

That's my understanding of how Don Jordan intended it.

No-one seems quite sure, though, why he suggested that the system is divided into several sections - apart from the bridle, of course. He may have gone with what ropes he had handy - his primary interest was 'proof of principle' - or there may have been an engineering reason we don't know of. Yes, we can speculate about 'it's cheaper/lighter having a thinner tail section' and 'it's easier to stow' but no-one seems to really know.

Having joins between sections opens the possibility of weakening splices/knots. There are arguments about that. I'm kinda in favour of one long continuous but modern high-strength line and no questionable knots or splices.... 'Occams Razor' principle, or KISS.

Is that 'splitting hairs'?

 

[geem]

Geem,,,,

That's my understanding of how Don Jordan intended it.

No-one seems quite sure, though, why he suggested that the system is divided into several sections - apart from the bridle, of course. He may have gone with what ropes he had handy - his primary interest was 'proof of principle' - or there may have been an engineering reason we don't know of. Yes, we can speculate about 'it's cheaper/lighter having a thinner tail section' and 'it's easier to stow' but no-one seems to really know.

Having joins between sections opens the possibility of weakening splices/knots. There are arguments about that. I'm kinda in favour of one long continuous but modern high-strength line and no questionable knots or splices.... 'Occams Razor' principle, or KISS.

Is that 'splitting hairs'?

If it came in a smaller lighter bag that would be good so maybe something to be said for the high tech line approach. Our JSD stows in two separate bags. That doesnt include the chain or bridle so its a weighty space consuming beast. Especailly when you hope you never need to use it. I think it goes in the same category as liferafts. Stuff you hope you never need to use. We could sink under the weight of safety gear!!

 

[Kukri]

I looked at Tony Curphey’s “Nicola Deux” at SIBS last year. I neglected to ask Tony this question, but I did notice the massive external chain plates on the quarters, the reduction in cockpit volume and the rebuilt companion hatch - the latter two items clearly very different to a standard Nic 32 and intended to allow the boat to lie stern to the weather safely.

I recall that I did ask Tony about recovering the series drogue and he laughed and said that he has no trouble.

The point I want to make is that if someone of Tony Curphey’s experience goes to these lengths to use a series drogue safely perhaps we all should and the cost of the drogue itself won’t be the biggest item.

 

[zoidberg]

I looked at Tony Curphey’s “Nicola Deux” at SIBS last year. .... but I did notice the massive external chain plates on the quarters, the reduction in cockpit volume and the rebuilt companion hatch - the latter two items clearly very different to a standard Nic 32 and intended to allow the boat to lie stern to the weather safely.

I recall that I did ask Tony about recovering the series drogue and he laughed and said that he has no trouble. The point I want to make is that if someone of Tony Curphey’s experience goes to these lengths to use a series drogue safely perhaps we all should and the cost of the drogue itself won’t be the biggest item.

Yes. I spoke with him there, too, but couldn't remember his name when penning the above #43. mea culpa. He'd deployed his drogue-kit many times, and recovered it equally often. His cones were due for replacement this winter, he said. The concept of massively beefed-up dedicated 'chainplates' for the JSD bridle attachments is covered in Don Jordan's notes and accessible via websearch. Other forums discuss this topic at length. All seem to have accepted that simply using the sheet winches is wholly inadequate.

 

[GHA]

.
The point I want to make is that if someone of Tony Curphey’s experience goes to these lengths to use a series drogue safely perhaps we all should and the cost of the drogue itself won’t be the biggest item.

Really think many here will ever be in anything near southern ocean type near survival conditions though?

(I have one and stainless angle welded to the Hull but very much doubt it will get used.. )

 

[Kukri]

Really think many here will ever be in anything near southern ocean type near survival conditions though?

(I have one and stainless angle welded to the Hull but very much doubt it will get used.. )

My manky auld boat got twice round the planet in the hands of her former owners without a series drogue, so it’s in the “nice to have“ list...