Jordan Series Drogue cloth

[mikereed100]

Originally Posted by Snowpetrel

I'm not so sure... My theory is that with the stretch in the rode the ones closest to the boat are dragged through the water much faster as the boat accelerates. And they also see much more sideways movement as the boat yaws. In addition they are nearer the surface and see more orbital currents, and disturbed water from any breakers.

In comparison the cones at the end are in deep steady water and are being towed in a much more consistent speed and direction.

My series drogue has perfect cones near the weight end and badly worn ones near the boat.

I would be keen to hear if anyone else has seen similar result with their drogue?

Cheers

Ben

I had the same experience and came to the same conclusion. After only a few hours, the cones closest to the boat were badly frayed while the ones nearest the end were ok. I felt that the damage to the cones were not only because of increased turbulence nearer the boat, but due to the stretchiness of the nylon rode which allowed the cones nearest the boat to take most of the load until the rest of the cones came into play.

I would not trust the drogue again and will make another using heavier cloth with a hem on the leading edge, as well as using Dyneema for the rode to eliminate the stretch.

[Jim Cate]

Some supporting info:

When I was experimenting with a small series drogue for use in towing our big inflatable, I first made the cones from 1.5 oz spinnaker cloth, and they were quickly destroyed.

I reason that this was because in this application, the cones are dragged along at six or seven knots, not the one or two knots when used in a full size drogue behind a yacht. The additional turbulence simply rips them to shreds in short order. This seems congruent with Ben's experience IMO.

For the dinghy application I ended up using heavy Herculite vinyl cones and they have lasted for years now. Would be too heavy for a normal JSD...

Cheers,

Jim

[wsmurdoch]

How do you lay out the pattern for the cones on the cloth? Does the seam have one side parallel to the warp and the other side parallel to the fill, or do both sides of the seam lie on the bias, or does it matter at all?

[Scare_Rab]

being "rip-stop nylon" I could not see the material having 'bias'.

Short answer... does not matter how you lay them out.

Mine were all higgle de piggle de,

[sully75]

RE: Dyneema, wouldn't you want some stretch? Seems like that would load the stern up a lot faster when the boat was accelerating. I just backed up my stern cleats but do worry about them ripping out of the deck in a worst-case scenario...

[wsmurdoch]

Originally Posted by Scare_Rab

being "rip-stop nylon" I could not see the material having 'bias'.

If you cut out a square of the cloth, sort of like a handkerchief, and pull it parallel to one of the edges, it stretches very little. If you pull it on a diagonal, it stretches a lot. No matter how you lay the cone pattern out on the cloth, one part of the cone will stretch easily and one part will not.

My question is: Where should the stretch be? Should it be on the seam or elsewhere?

[mikereed100]

Originally Posted by sully75

RE: Dyneema, wouldn't you want some stretch? Seems like that would load the stern up a lot faster when the boat was accelerating. I just backed up my stern cleats but do worry about them ripping out of the deck in a worst-case scenario...

While stretch is very important in a parachute, which is designed to all but stop the boat, it is not as crucial for a drogue. You don't get the shock loading that you do with a parachute, as the drogue is designed to slow the boat down, rather than to stop it. Most boats are still moving at 2-3 knots with a series drogue deployed. There was a bit of discussion about this a few months back here:
http://www.cruisersforum.com/forums/...ce-119799.html

Unless they are beefier than most cleats found on production boats, I would be wary of using cleats as an attachment point, even if reinforced. A better option would be a purpose-built plate bolted to the hull as outlined here:
Jordan Series Drogue - Design Loads and Attachments
A chainplate avoids issues with chafe as well.