Drogues, what do you think?

[Poey50]

Why is JSD gear seen to be at risk of breaking? Presumably because the warps/shackles have parted on a few occasions, in addition to Susie G's?

There's lots of discussion about open or closed thimbles, splices rather than knots, etc. but in general (famous last words I know..) we don't suffer from many lines parting because we know what works, through experience. (All bets are off if you are a crazy racer saving a few ounces in weight, of course)

A thought from someone who's never used a JSD, but have further oceanic ambitions into more challenging conditions:
Maybe the breakages were due to an over specced JSD with too many elements? How many is enough, or too many? It seems like a bit of a guesstimate?

I've been reading about JSDs for a few years now and Susie G's is the first I've heard of a line parting or the gear becoming damaged to the point of failure. There have, I gather, been no examples of boats being lost after JSD deployment. What problems there are seem to be the excessive fraying of cones (many of which were initially unhemmed and made of thinner material), problems of retrieval in some cases, and damage to windvanes caused by the bridle or leader hooking back under windvane rudders. The discussions on strength arise not out of a history of failure but out of a reasonable concern about using such gear in extreme conditions. There are now improving solutions to fraying, retrieval and windvane damage. The contributions of our serious "what-if?" members such as Neeves and Thinwater are much to be welcomed in helping to think through the issues before a serious event rather than afterwards.

 

[Kukri]

Much more than that going on....also looks like the jsd was sized for a boat lighter the hers after loaded up for the race, ...and she was off cape horn...... With no modern weather forecasting.... it's all pushing the probabilities in your favour..

Easily done. Here’s an extreme example:

According to one respected standard reference, my boat displaces 17.25 tonnes.

https://sailboatdata.com/sailboat/nicholson-55

According to her stability book, when loaded down to her marks, she displaces 25.234 tonnes:



“What’s eight tonnes between friends??” - well the weight of the ballast keel, for one thing...and almost fifty per cent of the displacement for another.

I think I know how this happened and it’s in two parts - Sailboat Data may have taken the aluminium alloy Nic 55 “Pacha” - a boat, built as a lightweight flyer, that won the Sydney Hobart - as typical of the class, but also the weight of stores, spares and gear is much more than we like to think.

 

[Gary Fox]

I've been reading about JSDs for a few years now and Susie G's is the first I've heard of a line parting or the gear becoming damaged to the point of failure. There have, I gather, been no examples of boats being lost after JSD deployment. What problems there are seem to be the excessive fraying of cones (many of which were initially unhemmed and made of thinner material), problems of retrieval in some cases, and damage to windvanes caused by the bridle or leader hooking back under windvane rudders. The discussions on strength arise not out of a history of failure but out of a reasonable concern about using such gear in extreme conditions. There are now improving solutions to fraying, retrieval and wind vane damage. The contributions of our serious "what-if?" contributors such as Neeves and Thinwater are much to be welcomed in helping to think through the issues before a serious event rather than afterwards.

Thanks, very informative, and yes I also want to think it through as well, not arguing with anyone just asking Q's.

 

[Fascadale]

This subject just won’t die............here’s a cracking thread on the same matter from about ten years ago. I think that the most recent threads show that our collective understanding and appreciation of JSDs have moved on along way.

Jordan Series Drogue, some practical questions

 

[zoidberg]

Most of us mere mortals are doing a trade wind crossing, followed by a return in optimal April - June. The probability of the conditions described are low......you can pick your weather window.
To be clear, I haven't done this yet. I'm heavily into the research.....

As regards Biscay....yes, but typically you're on a 3-day passage, and again most of us are doing it "in the season".

You might consider that the 'Jester Azores Challengers' who headed towards Terceira from Plymouth in 2016, I think, had '17 gales in 19 days' according to one report. Boats were damaged; some returned, limping into port.

There's a very long list of '3-day Biscay passage' venturers who got far more wind and waves than they or their forecasters bargained for..... and 'in the season'.

I suggest you broaden your research.

 

[zoidberg]

Suzy Goodall’s JSD seems to have lost one leg of the bridle before she was pitch poled and dismasted. I recall it was thought that the failure might have been due to the use of a knot in place of a splice.

First, Susie has never been clinically specific about how her JSD broke. She mentioned when questioned on this at a recent SIBS presentation event, with her sponsors Marlow Ropes, that she thought it had parted at/close to the bridle/leader connection. There were certainly superfluous double-figure-of-8 knots in the assembly which introduced a weakening, and the several sections were joined by a variant of the Girth Hitch - spliced loop through spliced loop.

What seems probable was that the line supplied was based on Don Jordan's simple diagram, suggesting line diameter against displacement.... for nylon rope. We know now, from published commercial research that has been refered to here, that nylon rope weakens when wet and degrades in strength significantly more than yottie polyester when repeatedly cycled - as in a JSD deployment.
It is not known what actual boat displacement the line in question was originally selected for. It may well have been for a far lighter boat than Susie's heavily-laden 'DHL Starlight'.

Someone else who posts on here commented that his 'Design Displacement' is just over 17 tons, but his actual measured displacement is over 25t.... a significant difference of 8 tons of 'beer and biscuit'.
Thanks to comment in here, we won't make that mistake... will we?

The point of these discussions, here and elsewhere, is to learn from others' hard-earned experiences so that we can have an improved prospect of coming through a serious weather event with only tales to tell.

The purpose of Don Jordan's drag device, evident if one reads his published material, is to prevent a capsize-inversion caused by a breaking wave strike. Those happen both near and far.

 

[Laminar Flow]

Ok, I'll give my two bits. I have twice been in conditions where I deployed a drogue or at least something similar. There were others.

First off the Maroccan coast on the way to the Canaries in 60 kts and ten metre seas when I deployed a couple of car tires (sorry can't remember if M&S all season or summer); worked fine. 25mm poly on 30cm cleats, fastened down with 6 M8 bolts through a composite deck. Boat: 30t lifting keel cutter. All you could see out of the deck salon windows (they are good for that) were grey walls of water racing towards the boat; there was no sky, one could not look up that high. We made it safely to Lanzarote; not everyone did.

Second time on a 43' R. Clarke sloop of 16t, returning from the Hawaiian Islands. We got caught out after losing the double forestays in some 60 kts and had no other option other than to run off. The drogue we used was of the Herman Melville type, a hand-me-down from a 50' fishing boat and about 30" in diametre and made of an iron hoop with crossbars and what appeared to be bullet proof, heavy canvas. It was about 3.5' long. We streamed it from a single 150', 3/4" line of 3-strand poly. The boat had a very narrow ( classic)transom and was equipped with a set of solid timber catheads (samson posts) either side of the cockpit. The drogue slowed us down from 6-7kts under bare poles to about 2kts. Held back by the drogue, every other wave would walk over the stern and right up to the deckhouse, leaving us sitting up to our necks in white water with the automatic life jacket inflating; we traded them for the standard toilet lid variety we had been using as cushions until then. The fun lasted for three days and we got pretty good at predicting which one would "get us". After, the drogue was no longer serviceable and badly frayed all over.

My observations:
Firstly, the current crop of boats does not appear to have decent deck gear, namely cleats and fairleads to handle the loads imposed by adverse conditions, either in port or at sea.

Secondly, it should be noted that slowing down a boat too much is not a good thing. Apart from the repeated and unpleasant experience of getting swamped & dunked every other time, the process is hard on the rudder and steering gear.

Thirdly, automobile tires, no matter how bald the tread, withstand the rigors of the sea a lot better than commercial drogues, even the professional models. Granted, they do not lock as sexy as the yachting variety, but you can keep them out of sight until you need to deploy them at sea where no one is watching. Pick a rim size and number that suits your boat's displacement.

 

[Neeves]

Laminar - its useful to have real life experience - from one of us.

Thank you

The only comment I would add is the unexpected realisation that when its that bad, you really don't want to be hand steering, but the autopilot (hopefully) is reliable but consumes power very quickly (more quickly than everything else put together). It seems contradictory to run an engine in order to have power for the autopilot when you are in a sailing yacht with, apparently, more than enough power from wind. But when waves are sweeping straight over the cabin roof - its not comfortable being a purist.

We do not carry a drogue.

I do note the comments on wear of drogues. The common usage of rip stop spinnaker fabrics seem a complete waste of time. There must be a better way/. Jordan introduced the concept - too many are following his early ideas. Not suggestion of being critical of Jordan, I'm criticising those that allow blindly

Jonathan

 

[Poey50]

I do note the comments on wear of drogues. The common usage of rip stop spinnaker fabrics seem a complete waste of time. There must be a better way/. Jordan introduced the concept - too many are following his early ideas. Not suggestion of being critical of Jordan, I'm criticising those that allow blindly

Jonathan

Ocean Brake, here in the UK, do high quality cones with thick material and taped edges. Although I made the drogue myself I was very glad to have used their cones.

 

[doug748]

I have nothing to add to this debate, only questions.

I dug out Heavy Weather Sailing last night, a late edition. It's generally very positive about Jordan drogues, but makes the following point in a couple of places :

"In the unlikely event of conditions becoming too bad ( ie, when already running under a drogue ).........for a boat to be pooped to become unsteerable or to pitch pole, then she is better off with her bow facing into the seas, hove-to............the decision is better made early than late.
............Thus owners of craft that do not heave-to comfortably will be better off with any well tried drag device........"

So if you do have a boat of the type that will heave-to reliably and may end up in that position in the end, it might be said a drag device is an unnecessary complication?

.

 

[Poey50]

I have nothing to add to this debate, only questions.

I dug out Heavy Weather Sailing last night, a late edition. It's generally very positive about Jordan drogues, but makes the following point in a couple of places :

"In the unlikely event of conditions becoming too bad.........for a boat to be pooped to become unsteerable or to pitch pole, then she is better off with her bow facing into the seas, hove-to............the decision is better made early than late.
............Thus owners of craft that do not heave-to comfortably will be better of with any well tried drag device........"

So if you do have a boat of the type that will heave-to reliably and may end up in that position in the end, it might be said a drag device is an unnecessary complication?
.

Morgan's Cloud discusses this. A frequently reported experience is that heaving-too is an option that has an upper limit for most boats. The problem then is switching from heaving-to to the deployment of the drogue without exposing the boat beam-on to a breaking wave. Morgan's Cloud recommendation is not to leave it too long to make the change.

 

[doug748]

Poey, I have edited my post to make it less vague.

 

[Poey50]

Poey, I have edited my post to make it less vague.

Ah OK. But aren't the Pardeys talking about heaving-to while hanging off a parachute anchor when it comes to very strong conditions?

Edit: I've confused Heavy Weather Tactics with Storm Tactics ... the latter is by the Pardeys.

 

[peter gibbs]

Seems to be popular on the Forum right now, drogues and associated stern gear.

Would you fit this specialist gear if you were going across the Atlantic? Or Pacific? Or towards Australia? At what point would you feel the need?

If not why not?

Could other tactics serve you just as well? What are they?

I am just interested, not going further than Cherbourg and the Isle of Wight myself. ;- )

.

A lot of us have a drogue, some even carry one on board. I do and in 35 years at sea never had cause to deploy.

Why did I buy - boat show offer? I recall clearly when getting into sailing all the bits that were recommended for the well kitted boat. Some more useful than others.

I too foresaw the day when all else failed and I could be on a lee shore needing a restraint from foundering. I even attended a lecture on serial drogues where it was demonstrated a long line of little'uns was superior to a big cone. Fascinating, as many matters maritime are.

Should anyone buy? Yes, for anyone likely to face heavy conditions, or longer open water passages / short crewed.

Do long lines thrown over the stern work as an alternative when running? Sometimes. I have experienced a heavy yacht in a gale with long lines streamed aft as an experiment - minor heading benefit, very little speed restraint was the conclusion. Smaller boats with less freeboard could benefit but the lines have to be long; I would prefer a drogue in this situation.

PWG

 

[noelex]

This 1984 paper published by the US coastguard and authored by Don Jordan, the developer of the series drogue, may be of interest. It discusses the results of tank tests on scale yachts using different types of drogues in breaking wave conditions.

https://apps.dtic.mil/dtic/tr/fulltext/u2/a158907.pdf

 

[doug748]

Ah OK. But aren't the Pardeys talking about heaving-to while hanging off a parachute anchor when it comes to very strong conditions?

Edit: I've confused Heavy Weather Tactics with Storm Tactics ... the latter is by the Pardeys.

Yes, sorry, being vague again. It was Heavy Weather Sailing originally by Adlard Coles. A collection of personal experiences and learned articles originally collected in 1967 but updated a number of times.

I must admit it is hard to imagine how you brace yourself to turn into the wind, or away from it, in those conditions. Bad enough in 25 knots.

.

 

[Poey50]

I must admit it is hard to imagine how you brace yourself to turn into the wind, or away from it, in those conditions. Bad enough in 25 knots.

Ditto.

Also worth factoring in (again from Morgan's Cloud) that around 2-4 times per day you might expect a wave twice the height of the mean height of waves. It seems to be these waves that account for the often mentioned experience after being rolled "it seemed to come out of nowhere" after a long period when the vessel seemed to be coping with the conditions. I was interested to re-read Jordan's original publication that Noelex posted. He recommends strapping in with seatbelts after launching the drogue. I'd forgotten that but recently watched the terrifying Queen's Birthday Storm documentary on YouTube. There were such serious injuries from being thrown around that I immediately bought a couple of seat belts.

 

[dunedin]

lots talk of trailing warps but didn't see and mention of JSD. I'm thinking as really no negatives from users of a jsd in really extreme conditions it's a thing to have onboard if there's a chance you'll ever go way out there......

Not sure you read the articles carefully then. Refers to Susie Goodall trying a drogue, and then changing to less drag of ropes and going faster which she said was better. And can’t get much more extreme than the pasting in the Southern Ocean that battered that fleet.
And worth reading the full Yachting World article if you can find it. The people slowing seemed to get at least as badly pasted as those who kept moving, not least as keeping moving gets passed by much less waves and less impact. I think the winner, who fared better than most, may have been one who practised the keep moving approach. Worth reading the full article

 

[GHA]

Not sure you read the articles carefully then. Refers to Susie Goodall trying a drogue, and then changing to less drag of ropes and going faster which she said was better. And can’t get much more extreme than the pasting in the Southern Ocean that battered that fleet.
And worth reading the full Yachting World article if you can find it. The people slowing seemed to get at least as badly pasted as those who kept moving, not least as keeping moving gets passed by much less waves and less impact. I think the winner, who fared better than most, may have been one who practised the keep moving approach. Worth reading the full article

Listened to Susie Goodall on The QUARTERDECK other day, running was discussed as one option , but needs very good helmsman, several as it's so tiring. Solo near impossible. Susie said jsd was the only way to go at night in a monster blow when it parted, windvane broken, no way to steer by hand, too dangerous not being able to see the breaking waves. Had it been day she may have considered hand steering as it was a race, like she did in other blows on the helm dawn til dusk. . Easier the get in than a para anchor off the bow she said. She's been there, we haven't.

 

[zoidberg]

It seems to me axiomatic that a 'last ditch' equipment intended to save life and boat must not fail structurally. Some 40 years on since Don Jordan gave us his life-saving invention for free, we have enough real-world experience to point the way towards building and using them better. Rope-makers and drogue-makers have always been an important part of this.

So also are real-world users.


'It must not fail 1' - Cones need to be made using suitable-robust materials. Ripstop nylon doesn't stay the course. Users are switching to much tougher stuff.
This is Jeanne Socrates' JSD after another RTW - but also note the rope.

'It must not fail 2' - Ropes or lines used need to be plenty strong enough, matched to the real laden AUW/Displacement of the boat. Wet nylon is not nearly as strong as polyprop/dyneema and degrades far faster.

'It must not fail 3' - Knots invariably weaken a rope substantially, as much as 50-60%. Proper splices are far more effective, and D/d ratios are important to maintain that efficiency.

'It must not fail 4' - Highly-loaded thimbles and the like must be free from sharp corners/edges and of the 'closed' form to prevent distortion and chafe.

The above design is readily available. Other designs and makes are also available, at other prices.


The question of easy recovery is still to be resolved, but it is a Different Question.