Beth Leonard and her partner on Hawk (a 47 foot Van der Stadt), who have a great deal of heavy weather experience, are currently making up a drogue with two large cones, separated by 100m of line.  They have a JSD aboard that they have used successfully in a Southern Ocean storm but have decided to experiment with this set up because of the difficulty in retrieving the JSD.  It seems to be manageable in a smaller yacht but quite daunting in larger vessels.  I used to have three large drogues that I was going to set in series but my friend got rid of them when he had the boat last year.  Gary, I think your set up will work well will work well if you make the drogue long enough (around 100 metres all up) and have a length of chain at the end to keep it deep, and if the devices you bought are strong enough.  That is the principal drawback of using fewer, larger cones.  The fewer and larger they are the greater the stresses on each one.  The drogues I had were made by Seabrake and they appeared to be very strong.  I like the multiple cones of the JSD (you can buy them if you wish as a kit or make your own or buy a complete drogue) as each cone is not under much load. 

The other consideration is whether your drogue has enough drag potential.  The reports of vessels deploying a JSD in severe storms that I have read all state that the vessel slowed down to about 1.5 knots, which seems to be the benchmark to aim for.  You could do what Paul did when you are doing sea trials.  Go out in 35 - 40 knots (not an easy thing to force yourself to do) and test it.  If you are still going too fast you can add another cone or two.  You might also be able to test its drag potential by using your engine and/or sails in more moderate conditions.

As for me I am still thinking.  I am a bit concerned that the bridle of a standard JSD might tangle with my outboard motor stowed on a bracket on the transom.  A few boats have had this sort of problem with their bridles.  As you come over the crest of a wave the bridle angles down steeply and could get under anything mounted on the transom.  One boat got it around the leg of their Aries wind vane with unhappy results.  If the wind stops for a while, as in the eye of a cyclone or when the wind changes direction as a trough passes, the drogue has been known to hang straight down until the boat takes up again with the new wind direction.  I'd rather set it off the starboard quarter without a bridle.  That way the drogue would be on the opposite side to the outboard bracket and lead away from it.  I would also be offering up the starboard edge of the transom to the seas rather than the flat transom, (though this does not appear to have caused any problems with other vessels.)  Mr Jordan and the US coastguard believe the bridle system is superior but I know a lot of boats that have ridden out severe weather with a drogue over the quarter, including the 19 foot Mermaid, that survived 5 typhoons in the North Pacific (see the book Kodoku by Kenichi Horie).  The vessel would yaw a little more and you would need to pay particular attention to preventing chafe, but then you need to do that anyway.  All the load is on one attachment point but it needs to be massively strong no matter how you set up your drogue.  I am thinking of welding a large stainless steel enclosed fairlead on the transom to contain the inboard end of the warp and stop it sawing back and forth.  When you retrieve the drogue you bypass this fairlead so the cones don't get snagged in it.  In all other respects, my proposed drogue will be a standard JSD set up.

Jonathan Snodgrass wrote:Gary, Please forgive me if I try to teach granny to suck eggs.  However, here goes.  It sounds as if what you have are sea anchors.  Sea anchors are intended to stay stationary in the water, probably deployed from the bows.  The cones on the JSD are designed to move slowly through the water, deployed from the stern.  Thus the boat moves forward slowly throught the water which maintains steerage on the underwater profile of the boat and keeps it going forward under control.  At least that is as I understand it from reading the blurb.   However, my experience of the JSD consists of buying one, rigging the chain plates etc, checking that it all goes together, stowing it in a locker and saying a prayer for kind winds.  Jonathan

I do believe that what matters here is the sum of the projected areas of all the cones.

So happens on our last visit to Yacht Grot (2nd hand boat parts dealer) we came away with 3 drogues for $20 (one large, two small) with a mind to build a kind of half baked JSD. 100m of line with drogues placed at 60m, 80m and  the large one at 100m.

I had the same notion of attaching a 3/8" floating line to the end chain to pull the cones in backwards, collapsed, with less effort. I think it's worth a try.
Further, I wondered if there could be, instead of a bridle and one series drogue, no bridle but two series drogues, each of half-length, joined at their outer ends by a chain, to which a retrieval line is attached. That should take care of the tangling danger - or increase it? : -) who knows without trying. It would be going back to what used to be done, towing a long warp in a bight, but with better drag characteristics.

I wonder whether it would make sense to use a drum, like an oversized bobbin for sewing thread.  Attach a long trip line to the end of the drogue, where the chain is, leave the other end on the drum.  When you want to retrieve start rolling the trip line onto the drum.  When you get to the chain and drogue, keep on rolling until the whole shebang is on board.  While you retrieve, you pull the rode backwards through the water, collapsing the cones and reducing the force.  The possible drawback is that you also have less force on the rode when you unroll to deploy the drogue, but I would hope that the drag on the rode is enough.  Make the first few metres of the bridle out of chain, so that it reliably drops into the water when you start deploying.  Mount the drum permanently on the stern, so that you don't have to mess about with it when you need the drogue.  Give it a cover, so that sunlight doesn't degrade the drogue quickly.

Is that likely to work?

Regards

Robert Biegler