Last summer I interviewed Randal Reeves when he stopped in Halifax during his Figure 8 voyage.
In that interview Randal shared that he had found it very difficult to retrieve his series drogue made from Dyneema™—brand name for Ultra-High Molecular Weight Polyethylene (UHMwPE) and a close cousin to Spectra™.
Neither the method Phyllis and I have tested nor Trevor Robertson's battle-tested system worked, because it was simply impossible for him to get the nipper (retrieval line), that both systems use, attached to the Dyneema without it slipping.
Not A Simple Problem to Solve
Trevor took up the challenge, but was not able to come up with a solution, despite trying a bunch of splices and being a fine and deeply experienced marlin spike seaman. The problem is that all of the ways to splice a loop in single braid Dyneena rely (in Trevor's words):
...on both legs of the line being nearly equally loaded for the splice to lock tight. Only one leg of this splice is loaded, consequently much of its strength depends on the seizings/whippings...
We also discussed this at length in the comments here at AAC with many innovative suggestions being made, including the use of climbing ascenders. But, in the end, the only option seemed to be using Dacron-sheathed Dyneema or Spectra. And that's where we have been for the last six months or so.
This is great news!
I’m looking forward to hearing how this works in real life. It seems like a solution without potential problems, but who knows? The only issue I have with this is superficial: The constrictor knot looks a bit “untidy”. That doesn’t really matter, of course, since it’s not there for looks. Still. it’s the type of problem that makes nerds like me curious if there could be a different knot using the same mechanics that is “prettier”. 🙂
I would bet there are other knots that would work, but to me that does not matter. The way I see it, we only have to tie these knots a few times and then never again, so who cares if there might be something prettier, given it’s a solved problem. As I often say, perfect is the enemy of good.
Great news, haven’t been able to sleep since this problem was left unsolved! A few comments/questions.
1. What sailor travels without bits of cordage in case one had a spare minute to be the first to solve the Dyneema JSD problem?! Geesh!
2. Thanks to John for confirming what I always thought – I’m just not anyone. Despite John’s confidence that anyone could look at the stopper and figure it out, I’ll confess that after 20 minutes I’ve realized there is no way I’ll get this no matter how long I look at it! Hope someone can provide some more detailed info.
3. It took me 10 minutes just to figure out the rolling hitch! John you said use a rolling hitch with an extra turn. I see that in the bottom picture. On the top picture I see a. two extra turns on the standing end and b. an extra half hitch on the working end. Is this assessment correct and is one or the other recommended. I get that these could be incremental additions if your recommendation of one extra turn wasn’t enough.
4. Stopper. A constrictor knot has 2 turns, looking at the top picture I see 5 turns. Add one turn for each tuck and that’s 4 turns. Is this a double constrictor? Are tucks just through one strand, or a couple, or does it matter?
5. I don’t understand the need for a constrictor. If the knot is passing through the strands, the force of the rolling hitch is simply on the ‘obstruction’ of the stopper. Isn’t the stopper just being held by jamming up against the dyneema strands? If so why can’t any knot just tucked in the strands work?
Sure the stopper knot is a bit complicated, but no more so than say an icicle hitch, and we only have to tie it a few times and then never again, so it’s not something we need to do in the heat of the moment. When I get home and have the necessary stuff to hand I will have a go. Maybe make a video.
As to changing the knot, sure you could do that, and it might work, but why bother given that this is the knot Angus tested to destruction? Point being, I would not make any changes unless I had the gear and time to destruction test the result.
Well, given that I am looking at a brand-new Ocean Brake JSD in my living room awaiting its new home aboard, this is nothing if not timely. What sizes of cordage are we talking about for the stopper knot and the rolling hitch, vis-a-vis the bridle/leader size?
I’m not sure it matters that much as long as the nipper is strong enough to take the load. Anyway, the main line in the photo is 8 mm so the size of the other lines can be inferred from that. And of course they should be scaled as the main line gets bigger.
Thanks, John. So noted.
I’m glad to see a workable solution, but I’ve a few questions/concerns.
1. A photo tutorial of that stopper knot would be handy. Maybe Ocean Brake should put that on their website.
2.What are your thoughts regarding the spacing of stopper knots? If the winch you’ll be using to haul it all back in is 10′ forward of the transom, am I incorrect in thinking that you’d need a constrictor knot about every 10 feet?
3. How are you unloading one nipper line from the winch to load the next? Maybe I’m missing something.
Sure a photo tutorial would be good. If they don’t do it, I will. That said, I really don’t think that tying the knot from the shots on the post is that hard, more a matter of settling down and putting some effort into it than anything else.
As to how retrieval works and knot spacing, see the links in the post for full details of both Trevor’s and our systems.
I must’ve read this article 3 times without seeing the references to the retrieval articles. How’s that for reading comprehension?!?! lol
wouldn’t it be possible that ocean break sales the drogue with the constrictor knots already in place?
Ask them and see, I can’t see why not. That said, it would be the customer’s responsibility to get them in the right place which might be hard to do before actually receiving the drogue. Point being I would still go to the trouble of learning how to do it DIY.
I recognise this is a little late but I’ve been having a few technical issues of late and I hadn’t thought to check this article until now. Yes, all new HMPE/dyneema drogues now come with the stopper knots spaced every 10/11 cones. You can always tie more, but generally speaking this works for most boats that are looking to fly a drogue.
If I don’t reply here, please do email me directly, as although I do read the articles here I don’t check it as regularly as I should.
Angus Francis Coleman
A workable solution but a lot of work to put in all of the constrictor knots. I was wondering if a simple figure eight knot would work. It would weaken the line a bit about 20% but I believe the dyneema is over kill by a reasonable factor. Each knot would shorten the line by maybe 3” but that could be added easily in assembly. They could also be put more often for flexibility.
I don’t have a rig to test it, but I would expect figure eight knots to slip under the pull from the nipper line. Also, as far as I know, dyneema very much doesn’t like sharp turns and being in compression – that’s why knots weaken dyneema significantly more than other types of cordage. I think it is imprudent to weaken the line that may have to support more than half the weight of your boat.
Alex, a quick google search seems to confirm dyneema is too brittle for knots. Thanks
I agree on the the figure 8 not being ideal. That said, I’m not sure that’s true about Dyneema being brittle since, as I say in the post, it creeps, unlike kevlar and it’s derivatives that do have a problem with self destruction if knotted or bent over a short radius. That said, I don’t recommend knotting Dyneem either: https://www.morganscloud.com/2017/12/09/running-rigging-recommendations-part-1/
With our retrieval system it would only be 2-3 knots, although more with Trevor’s. That said, it only needs doing once, so I don’t see it as particularly onerous. I would definitely stick with Angus’s approach since he has proven with destruction testing that it does not weaken the main line.
I guess I am misunderstanding. I would have a 295’ Long JSD. The retrieval line would need to be moved each time the the equivalent of the distance from the stern to the main winch was pulled in or less than 10’. Wouldn’t that mean something like 10’ spaced attachment points far enough for the load to be reduced enough to pull it in by hand? I am guessing at least half way?
The way I understand the two retrieval systems are this:
Using John’s method, the nipper and retrieval lines are used only to get the drogue loaded onto the winch. Once it’s on the winch, you “simply” crank it back in. John’s method takes place entirely from the winches aft.
Trevor’s method uses a turning block forward of the winch and is a bit more complicated requiring far more hopscotching of retrieval lines, and therefore more locking stitches. If I understand the text correctly, the drogue/cones never actually end up on the winch – only the retrieval lines.
I will say this, I don’t think either method is explained very well in text. I’ve spent quite a bit of time re-reading the instructions, and I’m not entirely certain I understand either.
If you have specific questions please ask them on the relevant article and I will try and help. Note that both articles have photos of the respective retrieval methods.
Have another read of the two methods linked to, neither require a nipper every 10 feet.
Hi Again Mark,
If you have questions after reading those two feel free to ask for clarification on the relevant article and I will try to help.
John – Can you clarify this statement on your retrieval method? I think this is what is preventing me from fully understanding what you mean. It seems like winching in on the retrieval line will cause the bridle to slacken, but you seem to be saying the opposite. I don’t understand the “preventing further travel” statement, either.
“Take the retrieval line to our largest cockpit sheet winch and grind it in until the bridles come tight, preventing further travel.”
Thank you for working through this and posting it. Well done. We all gain.
Thanks, Drew and Ken.
Fantastic! Only thing missing is how to actually tie the stopper knot. A youtube vid showing this would be perfect.
As I say in the article, I will mess around with that when I get home. That said, it does seem to me that people should be able to figure it out from the photos and Angus’s description. After all, there won’t be any YouTube videos offshore when seamanship problems like this must be solved with perseverance and logic. Sorry, nothing personal, but I’m a little cranky about this common expectation that all must be laid out to the final detail.
dumb question alert!
why not just have a line attached to the very end of the drogue? when you’re ready to retrieve it, just winch it into the boat from the line at the end. then the drogue wouldn’t fight the winching. am i totally wrong here? what’s the downside other than some extra line?
Not dumb at all. In fact it’s been asked so often that I have an answer at the ready: https://www.morganscloud.com/2018/11/14/storm-survival-faq/
Any comments on a Fiorentino Drogue sea anchor?
Your thoughts always valued.
We used to have a sea anchor, but now I think it’s obsolete technology, more here: https://www.morganscloud.com/2013/06/01/sea-anchor-system/
Hello John, – I’ve never used a series drogue but plan on getting one ahead of an atlantic crossing next year. As for the retrieval, what if the retrieval line was permanently attached to the very end of the drogue (where the chain starts), and therefore as long or a bit longer than the entire drogue itself, then when pulling it in you would empty the buckets as you pull the drogue through the water ??
Psea’s answer is correct, and we have a longer one here: https://www.morganscloud.com/2018/11/14/storm-survival-faq/
Thanks for the quick reply – I can see how that might happen. Looks like CYDY has something good going for it – lets hope so for everyones sake. All the best,
I just deleted a comment thread that was veering off to a bad place and contravened our comment guidelines. We need to be extra gentle with each other in these tough times so I will be extra vigilant about enforcing said guidelines: https://www.morganscloud.com/2013/11/10/aac-comment-guide-lines/
Also please note that my comment moderation decisions are final and that I do not debate them.
Waiting out the pandemic here in Nova Scotia has certainly given me plenty of time to read and re-read the many books/subject matter which, in my opinion, makes AAC a truly remarkable resource. As a relatively inexperienced long distance cruiser, it was this site that influenced my decision to purchase a Boréal 47 with Colin’s help and outfit it with a JSD. My wife and I sailed from Tréguier to Lisbon last year where we left the boat. All plans are obviously disrupted but eventually we will depart for the Canaries and on to the Caribbean then up to Nova Scotia. My JSD is onboard but not ready to deploy so I’ve been re-reading this book. This is probably a dumb idea but I’ll throw it out anyway. Do you think that in lieu of adding constrictor knots to stop the “nipper” from slipping, applying/soaking the Dyneema (in the said locations) with a non-skid or liquid rubber would be strong enough to hold the “nipper line? I have to admit, however, that Knots seem more permanent and secure.
Good to hear from a fellow Bermudian here in Nova Scotia. And thanks for the kind words.
If memory serves Drew also mentioned the possibility of using one of those compounds. I guess the only way to know for sure is try it and then experiment with loading a nipper line to see if it slips. That said, given that we know for sure that the the constrictor knot works based on Angus’ testing, including testing the main line to destruction with the knots in place, my own choice would be to go with that solution.
And finally, for those who don’t yet own a drogue but are ordering one: if I recall correctly, your first suggestion was to build the drogue using line with a dyneema core and a polyester cover or sheath. That should work, right? My drogue uses polyester line, (sheathed dyneema only for the bridle) which is heavy. I wish I had asked Ace Sailmakers to use the lighter sheathed dyneema. More expensive, but my drogue is a burden to move around.
Yes, I think my first suggestion is still fine. Also, while yours is heavy (like ours) it’s not all bad since you wont have the problems of the bridles whipping around in the way that Randal reported.
John what would you think of using heavier line for the bridle to calm down the whipping around. Alternatively adding a weight where the bridle joins the single JSD line.
I think that the heavier line would be a very good idea. Perhaps Dacron braid would be the best bet. I would not attach a weight at the bridle joins the main line, just too many possible unintended consequences.
Rather than installing a stopper with a constrictor knot at needed intervals as Angus Coleman suggests, use a simple overhand knot, doubled up on smaller Dyneema, for the rolling hitch to ride up on.
I would not recommend that since an overhand knot reduces the strength of the rope a lot, perhaps as much as 50% depending on rope type. On the other hand, Angus tested the main line to destruction with his knot in place and there was no decrease in strength.
I’m getting pricing for a JSD and would like a quote from Ocean Brake. However it seems that the website you mentioned has been taken over by some ‘WordPress’ page – whatever that is. Do you have an email address or some other means of contacting Ocean Brake? Thanks.
Sorry to hear that. I know he was working on a new site and what you are seeing is a base wordpress install, so I guess he is in the throws of it. It would be a lot better if he put up a coming soon page with contact, which is easy to do with WP plugins.
Anyway, Angus’s email is moc.ekarbnaeco@sugna
What I didn’t realise was that while fiddling with the settings, I managed to remove the holding page.
The new website is up and running (minus a few technical pages which are coming soon).
Sorry for any issues.
Good to hear.
I promise I really have tried to tie the Angus Coleman constrictor knot but I can’t make it come out like the two photos. And – although I feel stupid – I’m generally a fairly able person and a ‘trier’. Maybe it’s just me but if anyone has further guidance to offer that would be a great help.
That’s frustrating! I have not tried this yet, but my friend Wilson did manage it.
I’m up to my ears in stuff, but this winter maybe I can get him to show me and then make a short video.
Give me a reminder in December if you are still stumped.
Will do, John!
If an infinite number of monkeys can eventually write the complete works of Shakespeare … who knows, by winter I may have cracked it with all this lockdown time on my hands.
I do believe I’ve done it.
The key was not trying to slavishly copy the knot from the photos but to use some logic about how best to make the various hitches work together. I’ve tested it as far as I can and it seems sound and looks similar to the photos but I can’t swear it’s identical.