Jordan Series Drogue, some practical questions

[VO5]

What happens when the single point drogue you mention is thrown forward by a breaking wave, which then overtakes your yacht just as the absence of tension on the line leads to her broaching ?

Boo2

Good question.

Between the drogue and the line that pulls it is ten feet of 5/16 chain, plus the shackle and the swivel and the other shackle and the thimble on the end of the line. This is quite a weight. For that to happen the drogue would have to break surface.

This does not happen because the length of the line combined with the weight of chain creates a catenary that keeps the drogue submerged.

The vessel would have to career at a tremendous speed for that to be a risk.

Effectively the line cuts through the sea and the drogue is embedded always.

Depending on the tonnage of the vessel and the size of the recommended drogue so the length of the line and its breaking strain additionally is pre calculated togerther with what length of chain should be used.

The manufacturers in Australia provide a scale for this.

The scale is just not only tank tested, it has been tested in horrendous seas in the Bass Strait in storm conditions to ensure the proprtions are correct.

As the Bass Strait is shallower water than the surrounding ocean conditions there equal if not surpass wave action around Cape Horn, whose surrounding configuration of the ocean bottom is very similar.

As you know when seas meet shallows wave action is significantly aggravated, that is why such seas are used for testing these rigs as the size and bunching of waves are incredible.

 

[VO5]

Incidentally because I have just remembered...

It is ascertained by oceanographers and experienced seamen that the risk of rogue waves is present in storm conditions in a ratio roughly of a risk in one in a thousand consecutive waves.

These rogues are thought to occur when the prevailing wind increases against current but not with it.

Off the coast of Portugal we have the Portugal Current that streams south.

Several years ago I was sailing North, with a following heavy sea stoked up by an eight blowing from the south west and worsening.

At that time I had a fixed cone drogue, and a hankerchief jib.

The wave heights were approximately 4 to 5 metres.

One wave came along from the port quarter and this one was at least double if not 2 1/2 times the height of the others. Fortunately it was daylight.

I nearly got rolled over, but I attribute that to the fact that the cone was rigid and perhaps not correctly weighted.

 

[VO5]

Let's continue with this and progress it a bit.

Here is a bit of advice.

What you are pulling is not the vessel (or the notion that what you are pulling is several thousand tons).

What you are pulling is the drogue filled with water, that not only has a weight of its own as a result but additionally the effect of resistance.

You cannot take any short cuts with this or skimp in any way.

You have to ensure you "over rig"....funny statement...what does it mean ?

The biggest enemy is not tension, but chafe.

Sea anchors and drogues that have been lost invariably have not done so by the rope breaking, but by the effect of it being weakened by chafe. Chafe is the enemy you must guard against.

Do not be shy to over rig.

For the yoke (the Y shaped brace) use new rope. Use 3 stranded terelyne of a hefty safe working load and breaking strain far beyond what trailing the drogue requires, because additionally you can use it in a situation involved towing another vessel.

Use thimbles. Make your bight to tightly fit round it. Back splice in excess. I mean not 5 whatsits...complete 11 or even twelve. Do not taper. Marry the ends on finishing and then bind them after splitting. Hammer the sides of the thimble to ensure the fit is really tight round the bight. Then additionally secure it with a strong whipping along each of the straight sides.

For the bights that fit on the cleats, make these as tight as possible so that your clearance when slipping them over the cleats is minimal.

Take the trouble to worm and parcel them.

I have found these bags used by builders to transport and lift gravel and sand to be made of a material ideal to be used instead of canvas for use in parcelling and for many other uses on board..

Do not forget to mouse the shackles.

Use new chain for the catenary, and new shackles, do not skimp. BE BRUTAL.

Do not use galvanised thimbles and shackles, fork out and use stainless, the best, and oversize as well while you are at it.

Ensure when you store the rig you can deploy it without problems. You don't want a cat's cradle of a tangled mess when you need to deploy.

I carefully wind the line and then hold it together with soft woolen thread.
It keeps it tidy. The woolen thread is easy to snap, releasing the line for deployment.

Keep the whole assembly in the bag, ready. Keep it in a sensible accessible place and not at the bottom of a locker underneath everything else. Give it the importance it merits.

 

[Watson47]

V05 .... in fairness to the 'Jordan Series Drogue', it might be better to start a 'Seabrake' or a general 'Drogue' Thread. I am sure there is a lot of interest in the various options & I for one would love to see a photo of your Seabrake. I am looking at various options to replace a rather elderly drogue, but need to specifiy correctly for a displacement motorboat, weighing 25 tons.

 

[boatropes]

V05 .... in fairness to the 'Jordan Series Drogue', it might be better to start a 'Seabrake' or a general 'Drogue' Thread. I am sure there is a lot of interest in the various options & I for one would love to see a photo of your Seabrake..........

Agreed, a new thread for Seabrake would make more sense, and be very interesting. At the moment this thread feels like a catholic meeting hall which has been taken over by a visiting evangelist.
Cross references would be good though because both systems no doubt have their merits and followers. Can a moderator please assist?

 

[Lady Campanula]

Jordan-type Series Drogue

I'm interested in drag devices for heavy weather encounters, and I have a parachute sea anchor ( 'Here's one I made earlier' ) comprised of a heavy-drop 'chute with tape-reinforced seams and 2000lb cord on each of the tape-loops. I have a 4kg swivel and 800' of 18mm nylon braidline. Then a pair of 40' bridles, with hard-eye splices in the ends. The whole fits into a clean Tesco's plastic vegetable basket.

I'm now considering making a Jordan-type series drogue, and have been pondering the workload in making up ~100 fabric cones with sewn tapes. Then I found these....

They're free to me, about the same size as the fabric cones on offer, I can stow ~100 without difficulty, and I have both cord and tape to secure them to the warp. I'm wondering if anyone has an idea of the drag that 1 or 10 or 100 will provide, and any thoughts about effectiveness problems.

 

[barnaclephill]

Absolute rubbish. Ten metres maximum waves during uncommonly severe depressions. Maybe once per year.

"most dangerous"? Really. I think it has nothing on Cape Horn.

QUOTE"It was introduced to me by an old friend, Captain Philip Smith.

I wish to record publicly my gratitude to him.

The effect on the vessel once the SEABRAKE is deployed is astonishing.

Recovering it is easy. If the vessel is stopped it can be recovered without much effort hand over hand. If under way, it can be winched aboard.

It stows easily, is not clumsy or unduly heavy or bulky.

When the SEABRAKE is deployed she just settles down to the amazement of the crew and a brew can be started in any weather and hot tea broken out all round, or even a hot meal prepared without difficulty. Amazing. All else is nonsense I am telling you"UNQUOTE

No disrespect to your friend, but he ain't an cited as a qualified engineer with a published scientifically researched article sponsored by the Coast Guard of some superpower. It's like Leif's discovery versus Christobal's - one has backup and credibility, the other has an obscure discovery.

The stowage and retrievel are the same as the Jordan series drogues. The boat settling down to the 'amazement' of the crew enablling them to rest and cook is the same as for the JSD. The elasticity of the drogue holds the vessel to the waves, and all that stuff in the monologues earlier. The advantages & disadvantages of a single drogue/drag device from the stern are in the CG report. A single drogue puts your life in a single device rather than spreading your risks and force amongst one hundred devices through all sections of a wave.

 

[ytd]

the seabrake attachment chain is meant to keep it well under the breaking area of the waves so the drag it exerts is constant. I don't see how either of these drogues stop the back of the boat being lifted by the face of the wave. They are so long that any vertical rise in the stern will be absorbed by a small change in the caternary.

If you are just trying to get some drag what is wrong with a 100m length of anchor line with an anchor on the end to weight it down, unless the depth is less than 100m. Not enough drag, put another line out.

A more interesting question i whether it is better to deploy your drogue form the bow or the stern. I've seen the bow recommended on the basis that it's designed to punch through waves and the cockpit/companionway area is prone to leaks/damage after taking a few big breaking waves.

 

[Boo2]

A more interesting question i whether it is better to deploy your drogue form the bow or the stern. I've seen the bow recommended on the basis that it's designed to punch through waves and the cockpit/companionway area is prone to leaks/damage after taking a few big breaking waves.

From reading around, I've been given to understand that the reason for trailing drogues from the stern is because all modern yachts will yaw to the broadside-on position when held bows to the weather. This is because of their windage / underwater shape.

I agree that bows to seems intuitively sensible and asked here about the idea of using a riding sail but didn't get conclusive answers. There is the consideration that the stern of most boats has higher buoyancy than the bows and that if she is being continually swept by breaking waves then bows to might be no more damage resistant than stern to ?

Not speaking in any way from personal experience, you understand...


Boo2

 

[Fascadale]

Whilst I value the learned VO5 drawing attention to the Seabrake, and while I found his analysis on the expertise, or lack of it, of the USCG altogether illuminating I would wish to draw his attention to the first line of this thread.

I have decided to make myself a JSD this winter.

Should the most excellent VO5 wish to initiate a discussion comparing drogues then might it not be more appropriate for him to start another thread, as suggested by others?

Just a thought

 

[Talbot]

Whilst I value the learned VO5 drawing attention to the Seabrake, and while I found his analysis on the expertise, or lack of it, of the USCG altogether illuminating I would wish to draw his attention to the first line of this thread.
Should the most excellent VO5 wish to initiate a discussion comparing drogues then might it not be more appropriate for him to start another thread, as suggested by others?

Totally agree

Do you intend to manufacture the drogues themselvesas well. If so then there are some good videos on the www.sailrite.com on how to do it, and they sell the kits of sailcloth ready for manufacture into drogues.

 

[Fascadale]

Totally agree

Do you intend to manufacture the drogues themselvesas well. If so then there are some good videos on the www.sailrite.com on how to do it, and they sell the kits of sailcloth ready for manufacture into drogues.

Not quite sure how I'm going to do it yet.

I've seen the videos: the task itself does not look beyond my limited technical ability, parsimony is the new virtue, and I have these long dark northern evenings to fill so I really ought to do all the sewing myself BUT I am more likely to die of boredom, give up and never complete the job if I do it all myself.

In the search for the acceptable compromise I may buy half the droguelets ready made, make the others as well as do the threading and rope work myself.

(message to self, get on with the job, forget going out tonight)

 

[VO5]

V05 .... in fairness to the 'Jordan Series Drogue', it might be better to start a 'Seabrake' or a general 'Drogue' Thread. I am sure there is a lot of interest in the various options & I for one would love to see a photo of your Seabrake. I am looking at various options to replace a rather elderly drogue, but need to specifiy correctly for a displacement motorboat, weighing 25 tons.

Here is the link

www.seabrake.com

You will find all the information you need there.

 

[VO5]

From reading around, I've been given to understand that the reason for trailing drogues from the stern is because all modern yachts will yaw to the broadside-on position when held bows to the weather. This is because of their windage / underwater shape.

I agree that bows to seems intuitively sensible and asked here about the idea of using a riding sail but didn't get conclusive answers. There is the consideration that the stern of most boats has higher buoyancy than the bows and that if she is being continually swept by breaking waves then bows to might be no more damage resistant than stern to ?

Not speaking in any way from personal experience, you understand...[Boo2 /Quote]

That is correct, perfectly correct.

That is what I thought before I seriously began to investigate. There are countless textbooks that advocate streaming a drogue from the bow, and I thought conventionally it was the wisest thing to do.

But I discovered that all the accounts referred to drogues that were fixed.

I also discovered that the common problem was the effect of chafe at the bow roller which in many cases caused the rope to eventually part.

I was at first equally sceptical of trailing a single drogue.

But then I discovered the feature of flexibility of adsjustment in pull inherent in the design of the seabrake. This made sense to me.

I did not have long to wait to test the theory as we encountered a very nasty tropical depression off the Florida Coast, (not a Hurricane) a very nasty sea indeed.

I deployed the Seabrake from the stern, secured with a Y brace as I have already described. Perfect.

I have had two further opportunities this year to deploy, both in deep water in the Atlantic. One was the tail end of a Huuricane and the other a really ferocious cross sea on top of a deep swell.

In all cases the Seabrake performed magnificently, with the stern being held down and directional stability maintained throughout.

I will never go back to using any other method.

 

[VO5]

Absolute rubbish. Ten metres maximum waves during uncommonly severe depressions. Maybe once per year.

"most dangerous"? Really. I think it has nothing on Cape Horn.

QUOTE"It was introduced to me by an old friend, Captain Philip Smith.

I wish to record publicly my gratitude to him.

The effect on the vessel once the SEABRAKE is deployed is astonishing.

Recovering it is easy. If the vessel is stopped it can be recovered without much effort hand over hand. If under way, it can be winched aboard.

It stows easily, is not clumsy or unduly heavy or bulky.

When the SEABRAKE is deployed she just settles down to the amazement of the crew and a brew can be started in any weather and hot tea broken out all round, or even a hot meal prepared without difficulty. Amazing. All else is nonsense I am telling you"UNQUOTE

No disrespect to your friend, but he ain't an cited as a qualified engineer with a published scientifically researched article sponsored by the Coast Guard of some superpower. It's like Leif's discovery versus Christobal's - one has backup and credibility, the other has an obscure discovery.

The stowage and retrievel are the same as the Jordan series drogues. The boat settling down to the 'amazement' of the crew enablling them to rest and cook is the same as for the JSD. The elasticity of the drogue holds the vessel to the waves, and all that stuff in the monologues earlier. The advantages & disadvantages of a single drogue/drag device from the stern are in the CG report. A single drogue puts your life in a single device rather than spreading your risks and force amongst one hundred devices through all sections of a wave.

You are entertaining, if I may say so.

You mean to say the Bass Strait is not dangerous ?

You should check the records of recent Sydney to Hobart Races to become more properly acquainted with the facts.

Also it would serve you well to examine a chart for the area.

Anywhere that there is rapid shallowing to be found from deep water is to be considered, as a matter of prudent seamanship, particularly dangerous, whether it is the shelf around Cape Horn, The Labadie Bank, (remember the Fastnet Disaster ?) or the Bass Strait, I respectfully submit to you.

Frankly I have neither the energy nor the time nor the inclination to engage in tit for tat argument for the sake of it

I have provided above a link to the website of the manufacturers in Australia.

here is the link again:~

www.seabrake.com

They provide a very interesting short video that without doubt is in the interest of anyone with an interest in sailing, to watch attentively and derive their own conclusions.

They also provide a table detailing scaling recommendations and a list of alternative uses for the Seabrake.

My conclusions are derived from the practical application of the method and not from fanciful theorising.

I repeat I have no commercial interest.

I am a very satisfied user and extremy grateful to my friend for having introduced it to me and even more to the inventor, Capt. Abernathy, for having concieved it and making it available..

 

[Fascadale]

Esteemed Mr VO5

Please stop going on about Seabrakes, no matter how wonderful you think they are, on a thread about JSDs.

We are trying to discuss the making of JSD's: not whether or not Seabrakes are "a good thing"

I'm sure a Seabrake is a good thing and I now know you think it is.

However after much reading and a great deal of thought I have decided on a JSD. Please respect this decision. (As I said in the first sentence in the first post on this thread)

 

[VO5]

Esteemed Mr VO5

Please stop going on about Seabrakes, no matter how wonderful you think they are, on a thread about JSDs.

We are trying to discuss the making of JSD's: not whether or not Seabrakes are "a good thing"

I'm sure a Seabrake is a good thing and I now know you think it is.

However after much reading and a great deal of thought I have decided on a JSD. Please respect this decision. (As I said in the first sentence in the first post on this thread)

My Dear Chap,

The late Agatha Christie attributed the popularity of her whodunnits to a very simple collective flaw in her readership.

She commented that nearly everyone overlooks the significance of the obvious.

I have explained the obvious.

Now its up to you.

You have chosen to choose as you have.

My very best wishes to you in your endeavour and the very best of luck.

 

[ianabc]

Jordan Series Drogue was developed...

Jordan Series Drogue was developed and tested for severe conditions such as crossing the Columbia river bar .....

(which I believe is where the US Coast Guard rescue boat training occurs!)



"Jordan Series Drogue is a safety device designed to prevent the capsize and damage of both monohull and multihull sailing yachts and other vessels operating in the open ocean, in the event of a "worst case" breaking wave strike, as well as improving the motion of the boat in storm waves and to reduce drift.

The Jordan Series Drogue has been at sea for over 15 years. At least 1000 are in use all over the world. The drogue has been deployed through many storms including several hurricanes. No boat has ever been damaged and no crew injured. A typical comment from the skipper is " I did not feel threatened.".

The series drogue has been developed using modern engineering technology, including model tests in wave channels, computational dynamic analysis, and full scale testing by the U.S. Coast Guard at their motor life boat testing facility where boats are subjected to breaking waves formed on the Columbia river bar.

The drogue consists of a number of small cones woven into a tapered line with a small weight at the end. The maximum design load and the number of cones is determined by the displacement of the boat."


from the Ace Sailmakers site which I believe is associated with Mr. Jordan?

 

[fishermantwo]

From reading around, I've been given to understand that the reason for trailing drogues from the stern is because all modern yachts will yaw to the broadside-on position when held bows to the weather. This is because of their windage / underwater shape.

I agree that bows to seems intuitively sensible and asked here about the idea of using a riding sail but didn't get conclusive answers. There is the consideration that the stern of most boats has higher buoyancy than the bows and that if she is being continually swept by breaking waves then bows to might be no more damage resistant than stern to ?

Not speaking in any way from personal experience, you understand...


Boo2

Less stress on the rudder with the boat going the direction it was designed to go. Hanging off a sea anchor or drogue from the bow could have the vessel going astern stressing the rudder. When the storm passes your going to need that rudder.

Occasionally see a "Seabrake" on Ebay, they sell for about $50, if they are so good I might invest next time one appears. Not that I would ever need one, I tend to be a fair weather sailor in my retirement. I like the science of the Jordan though and even thought of sewing up a set during winter. Very labour intensive though and can easily see where the costs are.

 

[webcraft]

Oi, shampoo!

My Dear Chap,

The late Agatha Christie attributed the popularity of her whodunnits to a very simple collective flaw in her readership.

She commented that nearly everyone overlooks the significance of the obvious.

I have explained the obvious.

Now its up to you.

You have chosen to choose as you have.

My very best wishes to you in your endeavour and the very best of luck.

If I was as long-winded as you I could bore everyone to death explaining in enormous detail why the JSD is a much better device than the Seabrake in extreme conditions, but I won't bore everyone rigid with 'facts' that are irrelevant to the original subject of the thread.

Fascadale has indicated that he was looking for advice on building a JSD, which some of us have tried to give him. Unfortunately it has been drowned out by your deluge of irrelevant (to this thread) verbiage.

So - give us a 'brake' and take a telling. Go and start your own thread.

- W