Drogue Failures

[Dockhead]

Originally Posted by conachair

How would that work?

AFAICS It's completely different to anchoring where the boat is moving and a snubber slows the boat down over a longer distance, with drogues there's a huge wall of water trying to move the boat, elasticity won't slow the wave down, if you want to slow the boat down then a few metres of stretch won't make any different to the force needed to keep the boat slowed down as the monster passes below you. May even make it worse by letting the boat speed up a little before the full force of the drogue takes hold.
Guessing a lot, but I would guess Don would have went for dyneema if it were available as a practical alternative back then.

I agree entirely, and that was my point.


And I think Don DID go for dyneema eventually.

[conachair]

Originally Posted by Dockhead

I agree entirely, and that was my point.


And I think Don DID go for dyneema eventually.

Ah, sorry, non-elasticity of the rode

[thinwater]

Originally Posted by conachair

Ah, sorry, non-elasticity of the rode

Exactly. When a single element drogue pulls out of a wave face, a nylon rode can contract violently, causing the drogue to "snap" forward. Often this is reported as the wave "throwing the drogue forward," but it is actually the nylon recoil.


JSDs avoid this by using many elements, most of which are deep underwater.

[wsmurdoch]

Originally Posted by Dockhead

And I think Don DID go for dyneema eventually.

From Wikipedia, "Dyneema was invented by Albert Pennings in 1963 but made commercially available by DSM in 1990."

From jordanseriesdrogue.com. "On November 10, 2008, Don Jordan passed away peacefully at the age of 92."

The USCG report is dated May 1987.

I am not disputing that it is not a good idea (and personally think it may be), but does anyone have any solid reference to Don Jordan recommending polyester, UHMW, liquid crystal, Kevlar, or some other less elastic rope for his drogue? I have looked for, but failed to find either a reliable written reference or someone with personal knowledge.

Bill

[Dockhead]

Originally Posted by wsmurdoch

From Wikipedia, "Dyneema was invented by Albert Pennings in 1963 but made commercially available by DSM in 1990."

From jordanseriesdrogue.com. "On November 10, 2008, Don Jordan passed away peacefully at the age of 92."

The USCG report is dated May 1987.

I am not disputing that it is not a good idea (and personally think it may be), but does anyone have any solid reference to Don Jordan recommending polyester, UHMW, liquid crystal, Kevlar, or some other less elastic rope for his drogue? I have looked for, but failed to find either a reliable written reference or someone with personal knowledge.

Bill

I have only hearsay:


http://www.cruisersforum.com/forums/...ml#post2609567


Don Jordan being quoted somewhere, as saying the LESS stretch in the cordage, the better. Maybe someone has better information.




And Evans Starzinger discussing how both he and Dashew use Dyneema:


http://www.cruisersforum.com/forums/...ml#post1405797

[thinwater]

Slightly off-topic:


A 1983 article by Don Jordan I had not seen before. Just general interest.

http://mararchief.tudelft.nl/file/53253/

[thinwater]

I found these quotes from Don Jordon:

GordMay,14-10-2008, 10:06

Received the following reply to my query from Don Jordan:
Hi Gord,
Stretch is no problem. Spectra if (sic: "is") Ok
Don

"The increased stretch will not reduce the load, in a breaking wave strike. In fact it will increase it a bit. The drogue must pick up the load quickly before the boat broaches and must turn the boat into the wave. The cones near the boat perform this function and THE LESS STRETCH THE BETTER [emphasis added]."


I think it is worth noting that some drogue many facturers specify reduced stretch. Seabrake, FE, specs polyester DB.

I tested many drogues. Often I would allow over 100 feet of slack, wind the boat to full speed (engines downwind plus some sail, about 8-10 knots) and slam into drogues, to record peak foces and observe. You really do NOT get impact forces, because the drogues do not contain that much water and they pull through the water with the impact. Most of the time I was using polyester DB. I only used nylon for parachutes. The disadvantages of nylon (and someone will disagree) are recoil, skipping, and that it takes too long for the load to come on the drogue. (Parachutes are different--I'm not discussing that.)

From other comments I have read, I believe that Don Jordon did not consider his work to be either definitive or finished. He commented that the cone design in the report was probably inadequate. As a result of experience, the cones have evolved, and he would certainly accept that.

His goal, I believe, was to get these out in the field, where they could do some good. Now that we are collecting more and more experience, I am quite sure he would be pouring over the data and tweaking the design. The report lays out the principles and points out some vital details, but if experience points to possible improvements or the need for a little more strength somewhere, I think he would be supporting the evolution.

[wsmurdoch]

Thank you guys. That is what I was looking for.

http://www.cruisersforum.com/forums/...ml#post1414172

and

http://www.cruisersforum.com/forums/...tml#post215527

Bill

[Fi2010]

Maybe this will help clarify some of the concerns directed toward us.

Dyneema, Spectra…any type of UHMWPE rode doesn’t readily absorb water when wet. This increases floatation, which reduces drag so the rode won’t slow your boat down much. Additionally, the floating nature of UHMWPE can cause it to stack up (bunch up) on top of itself, sometimes becoming entangled. Attaching the proper amount of weight is important to help prevent tangling.

Nylon is a heavy fiber that absorbs water. This density really increases drag to slow a boat. It’s one reason we can convert a nylon rode into a warp for towing behind a boat. Nylon’s density also permits us to use less weight with a deployed speed-limiting drogue or para-anchor.

Nylon’s stretchy personality can cause shock loading. You can reduce this issue if you adhere to the Constant Rode Tension program mentioned in this thread. Our program has been reaffirmed through testing by NASA and more recently by the U.S. Navy. Our research might contradict what’s published by the industry and media, but test results have been highly successful. And yes, we feel weight placement at the drag device end is hugely important.

For unknown reasons, some of you are changing Jordan’s weight requirement for his JSD. This can increase shock loading of the JSD and might be a contributing factor to the JSD failures. Using heavier fabric cones in this instance will likely make no difference in stopping equipment failure. Consider sticking with Jordon’s original requirements.

Maybe this will help out. Here are some weight recommendations to consider by drag device inventor, Zack Smith:

JSD--Whether you use Nylon or a low stretch rode for the JSD, Smith suggests sticking with Jordan’s nylon rode recommendations “25 lbs. for small boats and 35 to 50 lbs. for larger boats.” A JSD with more than 100 cones will require the higher amounts of weight.

Para-Anchors and speed-limiting drogues-- Attach approximately 10 lbs. of weight to Dacron or Nylon rode without rode adjustment for the para-anchor. Also attach 10 lbs. of weight to the speed-limiting drogue. In extreme weather add up to 20-25 lbs. of weight to the speed-limiting drogue.

“If you use low-stretch rode like Dyneema, weight placement bumps up to 20 – 25 lbs. for the para-anchor and speed-limiting drogue. You can potentially use less weight with the para-anchor if you incorporate rode adjustment.”

It’s important to mention that many manufacturers do not recommend weight attachment to their para-anchor and/or drogue. There’s no explanation as to why. We disagree, weight attachment should be used in most applications.

[Dockhead]

Originally Posted by Fi2010

Maybe this will help clarify some of the concerns directed toward us.

Dyneema, Spectra…any type of UHMWPE rode doesn’t readily absorb water when wet. This increases floatation, which reduces drag so the rode won’t slow your boat down much. Additionally, the floating nature of UHMWPE can cause it to stack up (bunch up) on top of itself, sometimes becoming entangled. Attaching the proper amount of weight is important to help prevent tangling.

Nylon is a heavy fiber that absorbs water. This density really increases drag to slow a boat. It’s one reason we can convert a nylon rode into a warp for towing behind a boat. Nylon’s density also permits us to use less weight with a deployed speed-limiting drogue or para-anchor.

Nylon’s stretchy personality can cause shock loading. You can reduce this issue if you adhere to the Constant Rode Tension program mentioned in this thread. Our program has been reaffirmed through testing by NASA and more recently by the U.S. Navy. Our research might contradict what’s published by the industry and media, but test results have been highly successful. And yes, we feel weight placement at the drag device end is hugely important.

For unknown reasons, some of you are changing Jordan’s weight requirement for his JSD. This can increase shock loading of the JSD and might be a contributing factor to the JSD failures. Using heavier fabric cones in this instance will likely make no difference in stopping equipment failure. Consider sticking with Jordon’s original requirements.

Maybe this will help out. Here are some weight recommendations to consider by drag device inventor, Zack Smith:

JSD--Whether you use Nylon or a low stretch rode for the JSD, Smith suggests sticking with Jordan’s nylon rode recommendations “25 lbs. for small boats and 35 to 50 lbs. for larger boats.” A JSD with more than 100 cones will require the higher amounts of weight.

Para-Anchors and speed-limiting drogues-- Attach approximately 10 lbs. of weight to Dacron or Nylon rode without rode adjustment for the para-anchor. Also attach 10 lbs. of weight to the speed-limiting drogue. In extreme weather add up to 20-25 lbs. of weight to the speed-limiting drogue.

“If you use low-stretch rode like Dyneema, weight placement bumps up to 20 – 25 lbs. for the para-anchor and speed-limiting drogue. You can potentially use less weight with the para-anchor if you incorporate rode adjustment.”

It’s important to mention that many manufacturers do not recommend weight attachment to their para-anchor and/or drogue. There’s no explanation as to why. We disagree, weight attachment should be used in most applications.

Does anyone recommend using a JSD without a weight? I've never seen such a recommendation, nor have I ever seen a JSD without a weight. The weight is fundamental to the design -- I don't think the JSD would even work without a weight. Any drogue would be popping out and skipping along the surface without a weight -- what am I missing?



I sized my drogue for 50,000 pounds of displacement, which is 3 tons above the boat's light ship displacement, so 164 cones. I oversized the cordage up one size (14mm UHMWPE with UBS of 18.7 tonnes, vs. 1" nylon with UBS of 11.8 tonnes), and I'm using a weight about half again the recommended size of 50 pounds. The weight is a length of heavy ship's anchor chain.

[Fi2010]

Originally Posted by Dockhead

I have only hearsay:


Don Jordan being quoted somewhere, as saying the LESS stretch in the cordage, the better. Maybe someone has better information.


And Evans Starzinger discussing how both he and Dashew use Dyneema

"The LESS stretch is better" statement was coined by Gerrard Fiorentino and has been published for decades. It eventually became what we all know as the Constant Rode Tension program or theory. The theory is shown in the Complete Para-Anchor Set-Up video published in 2003. The instructions in the video explain how to reduce slack during para-anchor deployments.

The industry, including Jordan, have promoted stretchy rode setups. However, the industry is finally starting to accept Fiorentino and Smith's Rode Tension solutions.

Curious as to why you only mention Starzinger and Dashew in your dyneema rode comment and omit Zack Smith? Smith and Dashew are the ones who arranged the para-anchor and drogue deployment test using Dyneema rode.

Here's Dashew's report with his permission: https://www.para-anchor.com/reports/dashewlog.pdf

[Fi2010]

Originally Posted by Dockhead

Does anyone recommend using a JSD without a weight? I've never seen such a recommendation, nor have I ever seen a JSD without a weight. The weight is fundamental to the design -- I don't think the JSD would even work without a weight. Any drogue would be popping out and skipping along the surface without a weight -- what am I missing?


I sized my drogue for 50,000 pounds of displacement, which is 3 tons above the boat's light ship displacement, so 164 cones. I oversized the cordage up one size (14mm UHMWPE with UBS of 18.7 tonnes, vs. 1" nylon with UBS of 11.8 tonnes), and I'm using a weight about half again the recommended size of 50 pounds. The weight is a length of heavy ship's anchor chain.

You're taking our comment about sailors changing Jordon's weight recommendations for the JSD out of context. There's never been any mention of using a JSD "without weight".

What the JSD suppliers and promoters on this website are doing is recommending less weight than what Jordon requires for his product. An average of 35 to 50 lbs. for the typical cruising boat.

Instead of 50 lbs. of weight, one supplier is recommending 15 lbs. You claim you're going to use less than half the weight recommended by Jordon. Those who change Jordan’s recommendations without supporting research are likely putting sailors at risk.

We believe many of the JSD reported failures are due to the improper amount of weight attached to the device. Or because of cheap parts as another moderator mentioned. We're trying to help out. You do realize that JSD failures don't help our company?

[Dockhead]

Originally Posted by Fi2010

You're taking our comment about sailors changing Jordon's weight recommendations for the JSD out of context. There's never been any mention of using a JSD "without weight".

What the JSD suppliers and promoters on this website are doing is recommending less weight than what Jordon requires for his product. An average of 35 to 50 lbs. for the typical cruising boat.

Instead of 50 lbs. of weight, one supplier is recommending 15 lbs. You claim you're going to use less than half the weight recommended by Jordon. Those who change Jordan’s recommendations without supporting research are likely putting sailors at risk.

We believe many of the JSD reported failures are due to the improper amount of weight attached to the device. Or because of cheap parts as another moderator mentioned. We're trying to help out. You do realize that JSD failures don't help our company?

I really don't know what you're talking about. You're not responding to my post, which it seems you didn't read. Or maybe you have confused me with someone else?



I did not accuse you or anyone else of recommending undersizing (or eliminating) the weight. On the contrary, I was questioning someone else's assertion that others have done that -- I've not personally ever seen any such recommendations.

[Fi2010]

Dockhead,


Just responding to post #55. Sorry if we misunderstood.

[Fi2010]

Originally Posted by mikereed100

We made a JSD using the Sailrite kit for the cones, attaching them to nylon rodes. The cones were 2oz ripstop and, after only a few hours deployed in F9 conditions, were shredded beyond use. The trailing edges were frayed nearly as much as the leading edges. The cones at the front of the drogue were affected more so than those at the rear. Sailrite no longer offers cone kits, which is probably a good thing. We made a new JSD, using 4oz polyester and hemming the leading edge. We re-used the nylon rode, as it is still in good condition. If I were to do it again, I would probably go with an even heavier weight cloth for the cones and would spring for UHMWPE rode. A 360' drogue with cones is a beast to move around the deck and store, and even heavier when wet. If starting from scratch, using UHMWPE is almost a no-brainer as the cost vs nylon, when matched for breaking strength, is roughly equivalent.

A quick comment on attaching the drogue to the boat. A friend recently deployed his JSD, attaching the bridle arms to welded stern cleats using the standard round turn and cleat hitch. The drogue ran out smoothly, but he then watched helplessly as the new nylon line slipped right off the cleats, one after the other, and his new drogue disappeared under the waves. A good reminder to use eye splices, or better yet, eyes shackled to chainplates that eliminate any chance of chafe.

Sailrite quit supplying the JSD cones, because of liability. We also think it might have something to do with the unnecessary smear campaign that occurred against Sailrite. Matt from Sailrite was upset by the forum attack and contacted Zack Smith to learn more about why the JSD cones can fail. The following is an e-mail conversation between Matt and Smith a couple of years ago. The only relevant details removed are what Matt posted online and Smith’s linked research showing JSD weight requirements:

“Hi Zack,
I was wondering if I could bug you about a current questions we are getting on the JSD. There is a lot of talk going around about using heavy 6.5 oz Dacron to make the cones so they don’t fall apart during the first use of the drogue. I wrote the reply below which is my stance on the current line of questioning. I know you are very knowledgeable about safety devices in general so I thought of you as an expert to give your input on cone weight…”

“Hi Matt,

Nice talking with you today.

Comments left on our comparison video from Dave (ace sailmakers) and Fiorentino cover the amounts of weight recommended for the Jordan Series Drogue. It might be a good idea to know what the discrepancies are for any future posting on the forums or your own blog. At least you will be accurate regardless of what anyone may claim. Let me know if you run into problems from any arm chair sailors or fake bloggers. We can always help you out if Fiorentino has an account with the forum.

As we already discussed, it's irrelevant how beefy you make your equipment if shock loading persists while deploying any equipment. Also, something I forgot to mention to you. It's possible a customer may actually damage the cones during the retrieval process and mistakenly think it was from actual use. I've damaged cones because they tend to get caught up on the winch if I'm not careful. I shot video with a well-known sailing couple (not edited yet) where the cones were damaged at the winch and quarter chock. The downward pull was probably why the cones became knotted up at the chock. Boat design may have factored into the cone damage at the quarter as I've not experienced that particular issue until the video shoot.

Fiorentino has a friendly repair or replacement policy regarding their equipment, because they have had a couple of commercial fisherman claim the chute just broke. After letting the fishermen know Fiorentino replaces it for free regardless of circumstance, the fishermen finally admit to running over the parachute! Sometimes people are afraid to admit they made a mistake…”

For the record, Sailrite is our competitor, but we recommend their company. The company is a family run business who care about their customers. The moment Sailrite stopped supplying their cone kit is when the importers likely raised their prices. Without competition you tend to see cheaper product at higher prices.