Jordan Series Drogue experience

[transmitterdan]

I imagine the cleats for a JSD should be capable of hanging our boat from a crane over pavement and my heart does not give out from pounding. If your cleats can do that then they are ok for a JSD.

[wsmurdoch]

Is there any need for the cleats to be stronger than the drogue's single line at the point just beyond its junction with the bridle?

The drogue for my 13,500 lb displacement Pacific Seacraft 34 has the Sailrite recommended 5/8” diameter braided nylon single line. In my case it is Sampson Cordage “Super Strong” double braid nylon with a breaking strength of 15,200 lbf before any de-rating for splices or being wet. De-rated to 90% for each, it might have an in service breaking strength of 12,300 lbf.

The report referenced by Evans, Cleats : BoatUS Foundation, is quite helpful. A 6", four bolt, stainless steel cleat failed at an average load of 6,893 lbf. I suspect that the strength of a cleat increases, like the strength of rope, with the square of its size giving each of two 10" cleats a breaking strength of 19,000 lbf. The rope would part before a cleat would fail.

Even if the strength of a cleat were to only increase linearly with its size, a four bolt, stainless steel 10" cleat would have a strength of 11,500 lb. Given the distance between my cleats, the stretch of nylon under load, and the length of the two legs of the bridle, I find it hard to see how all the load could be put on one of the cleats causing it to fail before the single line of the drogue would fail. Again, the rope would part before the cleat would fail.

[UNCIVILIZED]

With regard to the issue of the very, very long wavelengths found in open ocean storms, I can't help but to wonder if it might be wise to "tune" the length of the drogue package a bit. For instance if what's normally recommended for your boat is a 125 cone drogue connected directly to the bridle. What if you were to have the following, all linked together in a series:
- Bridle
- 100' Dyneema
- Drogue with 75 cones
- 200' Dyneema
- Drogue with 75 cones
- Tail weights as needed/recommended

That way the overall length of the package will be around 600', & in theory, provide protection for the boat both from large waves near her, as well as the longer wavelength ones, thanks to the package's overall extended length. And the above mentioned line lengths are of course open to being subsituted for with alternatives as one sees fit. Thoughts?


EDIT: Now that it appears that the patent on Dyneema & or Spectra has expired ??? Does anyone have knowledge of some of the less expensive equivalent lines on the market? And if so, could you please be kind enough to post links to same if you have them.

[estarzinger]

^^ just fyi . . . quite a few series drogues (including those by Ace, and ours) are in fact made in two pieces (cow hitched together usually), more for the fact that the required rode strength decreases along the rode . . . . so the tail end half can be made with smaller line than the front end half (saving size and money).

[transmitterdan]

The strength of the cleat is limited by its mounting material in most cases. Cleats don't usually break, usually the boat holding the cleat breaks.

And "breaking strength" is a minimum value not a maximum value. That actual breaking strength can be more than specified. How much more is unknowable without lot level testing of rope batches. Better the rope break than the boat.

[NevisDog]

Don Jordan wanted a safety device that you simply dump in the water when the going gets too dangerous. It should be pre-rigged, then in those atrocious conditions that we all hope to avoid, you dump it overboard and go below - no scrambling on the foredeck with ropes and canvas, no securing of ropes and getting them tangled, just dump it from the cockpit - job done.

The problem we see with single drogues (and para anchors) is, unless the rode length is correctly sized to the wave train, they tend to surface and can be tossed forward by a wave (from memory, some even being tossed in front of the vessel they are supposed to protect). But... if, as may be the case, the greatest capsize danger is from wave strike from a different angle to the wind (then tumbling freefall down the face of said rogue striking wave), then the shortest leader possible (long enough to stay submerged but no more) is desirable; I worry that adding any extra length to a series drogue my entirely negate its purpose.

The only guidance on this I'm aware of is the DDDB.

[wsmurdoch]

Originally Posted by transmitterdan

The strength of the cleat is limited by its mounting material in most cases. Cleats don't usually break, usually the boat holding the cleat breaks.

Yes, and that is why I asked my boat's maker, Pacific Seacraft, if the stern cleats were capable of withstanding the required load. The assured me that that was the case. The BoatUS report allowed me to confirm that the cleats and their bolting (which was the reported failure point) were suitable for the required load. I have to rely on the manufacturer of the boat for the deck construction as I am unable to evaluate it myself short of actual testing.

Originally Posted by transmitterdan

And "breaking strength" is a minimum value not a maximum value.

The breaking strength of the tested cleats in the BoatUS report were the averages, and both Sampson and New England Ropes report not the minimum breaking strength of their nylon braid ropes but rather the average breaking strength. In checking around on the rope maker's web sites this morning to confirm that, I also found that Samson recommends de-rating cow hitched eye splices with similar sized ropes 15% rather than the 10% that I mentioned for the eye splice.

[rgleason]

Mike Reed thank you. This appears to be a reasonable retrieval solution. I suppose it requires that storm is past. Is there anyone who can add experiences?

http://www.cruisersforum.com/forums/....php?p=2083217

In any event, I really don't think a trip line is necessary. As I mentioned previously, we were able to easily recover our drogue by hand by simply leading it to the bow and pulling it over the anchor roller. If you are able to motor at all into the wind and seas, recovery over the bow is easy.

[Suijin]

Originally Posted by UNCIVILIZED

Something which is mentioned with some regularity in the DDB. Especially as at times one's primary drogue may get irreperably damaged, or have to be cut away for some reason etc. And also that sometimes you don't want to slow the boat down quite as much as a JSD does. To which effect, some boats have multiple types of drogues onboard to match conditions. Be they commercial products, heavy warps, an old car tire, or all of the above plus a JSD.

On this, I'd be curious to hear stories from folks who've been out there in these kinds of situations, & their experiences as relates to the above & in general.

The Galerider is a great back-up drogue; affordable, robust, compact, simple, and provides one of the best pieces of kit for emergency steering if you lose your rudder (bridle to midships cleats and back to primaries).

[UNCIVILIZED]

Originally Posted by Suijin

The Galerider is a great back-up drogue; affordable, robust, compact, simple, and provides one of the best pieces of kit for emergency steering if you lose your rudder (bridle to midships cleats and back to primaries).

Midships cleats, or blocks? As cleats make for crappy turning points to winch lines around, especially highly loaded ones. And you'd likely have line failures due to point loading, & tiny radii.

[Suijin]

Originally Posted by UNCIVILIZED

Midships cleats, or blocks? As cleats make for crappy turning points to winch lines around, especially highly loaded ones. And you'd likely have line failures due to point loading, & tiny radii.

I meant as attachment points. I have extremely beefy midships cleats. I put blocks on them with soft shackles. From there I have unobstructed line to the genoa turning blocks, or straight to the primaries themselves which is even better.

[UNCIVILIZED]

Originally Posted by Suijin

I meant as attachment points. I have extremely beefy midships cleats. I put blocks on them with soft shackles. From there I have unobstructed line to the genoa turning blocks, or straight to the primaries themselves which is even better.

Got it. Hope you have a beastly set of blocks That's a lotta' load, what with the 180 deg. turn & all!

[Suijin]

Originally Posted by UNCIVILIZED

Got it. Hope you have a beastly set of blocks That's a lotta' load, what with the 180 deg. turn & all!

Remember that rig is for steering, not for full on storm drogue. The latter goes from the primaries straight out the hawsepipes.

That said I do need to pick up a pair of heavier blocks. I have some huge snatch blocks but they're not built for that.

[Seaworthy Lass]

164 cones have arrived from OceanBrake in the UK.

I am pleased with the quality. Heavy dacron has been used (sold as 7oz). Both edges are hemmed. The price was roughly half that from Ace Sailmakers in the US, calculated using current conversion rates.

I will be using Acera for the line: roughly 1/3 each of 8, 10 and 12 mm to meet the strength requirements for a vessel of our displacement.

This is how the cones look:

[NevisDog]

Originally Posted by Seaworthy Lass

164 cones have arrived from OceanBrake in the UK.

I am pleased with the quality. Heavy dacron has been used (sold as 7oz). Both edges are hemmed. ...

But I copied down their advertising description (from eBay - 'englishseadog' is one of OceanBrake's monikers): "7.2oz yellow polyester/dacron, 3x12mm tapes + taped mouth and exit..."

Cones look good but I'm surprised they don't meet their own description.