Dyneema backstay with integral SSB antenna

[jfranta]

Its been awhile since we tested it but we saw too much constructional elongation in it and the other SK78's that we tested for our liking. If you can deal with the elongation issue in your application, than its fine.

Not sure if they have changed anything about it since testing it.

NER's HSR is the same as the Dynice dux in performance, its good stuff.

Originally Posted by Benz

John Franta, while you're paying attention to this thread, may I turn aside to ask what you make of Marlow's MAX? It claims to be the same as Dynice Dux and NER's HSR. Have you played with it at all?
Thanks
Ben
Zartmancruising dot com

[estarzinger]

Originally Posted by jfranta

5 degrees seems large to me also, but we took over 40 lbs off the rig just on the uppers and intermediates.

As a very friendly suggestion, you should organize a before and after incline test when you do a rerig like this. It is easy to do and would give you actual valuable data.

Beyond that, both running a VPP and getting full before and after measurement certificates, would give you further good data. However, these would cost a little money and take a bit more effort.

Those steps would allow you to offer your customers real information, rather than anecdotal feelings that no-one really believes.

Just two quick asides on reducing weight aloft - (1) I hope you realize and inform your customers that increasing righting moment also increases loads; and (2) usually the performance gain comes more from reduced pitching (aka hobby horsing) rather than reduced heel angle.

Originally Posted by jfranta

Evans, sorry that you spent so much money to prove that you don't have to be as conservative with designs as we are.

I took the time and effort (and money) to try to help you understand that that you had misunderstood one of the most basic principles in rope loading calculations and as a result you were publishing false and misleading information. I did it with the best of intentions to help my fellow sailors and to help you.

Your misunderstanding was truly fortunately in the 'conservative direction and you did not lose any rigs because if it; but it is not so comforting to have a supplier of a major structural component so obviously not understand the most basic calculation. You were very clear and very public in your misunderstanding over on the SA threads, so you cannot with a straight face now claim you understood it all along and were just being conservative. I do hope ultimately you appreciate my effort to help you.

like a spliced eye with a whipping for standing rigging

Actually I suggest a spliced eye with sewn bury (not a whipping). . . . .which is what essentially every knowledgeable practitioner in the field suggests. The heavy lifting guys do not use the brummel at all - and anyone of them (the majors there) has more experience and more testing and higher consequences that the whole yachting business. NER also agreed with my recommendation, NASA uses what I recommend rather than brummels in the re-entry parachute shroud line, etc etc. The sewing, when done properly, is no more vulnerable to flutter or UV than the line itself; and it is easy to make multi-redundant if you care to. The brummel is not too bad, and it does look 'clever', but it is simply not best practice. (but it is not a big deal - especially if there are other weak points introduced into the design elsewhere)

In this thread, you said Rod rigging has an almost infinite life? I bet that would make the Navtec (now Hayn) guys cringe!

actually I have in the past discussed it with them. They agreed on an engineering level (there are other business considerations than engineering), given the caveats that I also included in the comment above - that it be properly speced (so it was not fatiguing) and properly maintained. I am guessing you are not much up on the concept of fatigue limit. Essentially the only ways to kill it in that situation are significant user error or manufacturing defect. You can kill the terminals if you allow water to get in them and freeze.

ps my philosophy is that "to error is human; to acknowledge it and learn and move on is adult" . . . . .

[jfranta]

Evans, you continue to make great assumptions in your postings. I have told you many times that we have data that supports what we are doing, always have. You don't seem to hear things you don't want to hear. Let me make this clear so you have a chance of understanding this. We put Dynice Dux together with our hardware and tested it, using statistical samples, to come up with our recommendations of using it with our hardware. We would never rely on just an equation for a structural product. Hear that Mr Starzinger, we don't rely on equations for our products. The proof of what we do is in the pudding. In the field, on the boats. Products have to work on the boats. Trying to say we don't know what we are doing when we have 10 years of history says more about you. We have many customers now that have rigged their second or even third boat with our standing rigging.

We are much more conservative than you with our recommendations on a paradigm shifting technology, you say we don't have to be. We respectively disagree with you Evans. You can recommend a smaller bend ratio, you got nothing to loose really. We, specifically for standing rigging, are staying with a larger ratio for lots of reasons, not just engineering.

We have supporting data for our products and we have a positive history with our products. You can say we are fortunate, but 750 boats is alot to get fortunate with.

Putting this another way, I might add that trying to discredit someone is not going to gain you any browny points with anyone, just drama. Maybe you should take that back to the Sailing Anarchy forums, they like that stuff there.

"Your misunderstanding was truly fortunately in the 'conservative direction and you did not lose any rigs because if it; but it is not so comforting to have a supplier of a major structural component so obviously not understand the most basic calculation. You were very clear and very public in your misunderstanding over on the SA threads, so you cannot with a straight face now claim you understood it all along and were just being conservative. I do hope ultimately you appreciate my effort to help you. "

[estarzinger]

John,

You did not know that the load on strands in a loop were half what they were on the strands on the main part of the rope. I have copies of e-mails you sent me which very explicitly demonstrate that (remember the ones you sent me when I was in the hospital - you asked "where are the two legs"), and you repeated this in public forum posts.

Take me to court if you think it is libelous, you will lose (very quickly), and pay both our court costs.

You are fortunate in your specific application, because you spec for stretch, which results in 'over strength', providing huge margins for error. I am not arguing about or with a 'conservative choice' - that is a business decision, but as I said above I personally would be uncomfortable with a supplier of a major structural element who does not appear to understand some fundamental basic principles of their craft, and I personally have a hard time recommending them to others - that is my being careful when I try to help other sailors.

If you have before and after incline data post it, it would be more useful and more compelling marketing than saying your clients feel there is a heel reduction. Same with before and after measurement certificates.

[jfranta]

Evans, Please read the last post at least 10 times. We have made standing rigging for more than 750 boats, successfully. But we might have interpreted one chart wrong, in all the reams of data that we looked at, about 10 years ago. Still we managed to produce succesful rigs for all these boats. That was just luck though.

As I said before I have learned alot about Dyneema since I started using it for my standing rigging product. I have always had large factors of safety and that is no accident as I know it is needed when introducing a new, and innovative product. There are always unknowns along the way and they have to be designed for.

I appreciate your input on our marketing strategy. What is your background on marketing? You seem very confident in your recommendations.

Originally Posted by estarzinger

John,

You did not know that the load on strands in a loop were half what they were on the strands on the main part of the rope. I have copies of e-mails you sent me which very explicitly demonstrate that (remember the ones you sent me when I was in the hospital - you asked "where are the two legs"), and you repeated this in public forum posts.

Take me to court if you think it is libelous, you will lose (very quickly), and pay both our court costs.

You are fortunate in your specific application, because you spec for stretch, which results in 'over strength', providing huge margins for error. I am not arguing about or with a 'conservative choice' - that is a business decision, but as I said above I personally would be uncomfortable with a supplier of a major structural element who does not appear to understand some fundamental basic principles of their craft, and I personally have a hard time recommending them to others - that is my being careful when I try to help other sailors.

If you have before and after incline data post it, it would be more useful and more compelling marketing than saying your clients feel there is a heel reduction. Same with before and after measurement certificates.

[estarzinger]

Originally Posted by jfranta

I appreciate your input on our marketing strategy. What is your background on marketing? You seem very confident in your recommendations.

LOL . . .it's off topic, but perhaps a fitting way to end the discussion . . . I majored in marketing in B-School, was the brand marketing manager for aquafresh toothpaste, then the leader of the marketing practice for McKinesy & Co (perhaps the best such worldwide consulting company), then SVP of marketing at GE. So, I have some modest experience in the field

[poiu]

I can feel a lot of love here, for rope if nothing else. There are some great contributions to this fascinating subject. Thank you everyone.

[Viking Sailor]

Originally Posted by poiu

I can feel a lot of love here, for rope if nothing else. There are some great contributions to this fascinating subject. Thank you everyone.

So, about your need for a SSB antenna... You have a plan?

[poiu]

Originally Posted by Viking Sailor

So, about your need for a SSB antenna... You have a plan?

Partly. But not finalised, I'll give it a go with dyneema. I haven't finished my research yet. I should speak to Colligo, consider if I can make my own and if I go that way to check what I can get and what costs, check out my hydraulic equipment, and to work out how and if I can cover the rope, work out how to attach it to the end fittings and so on. I think I will bury the wire antenna though.

So two out of ten decisions made.

[estarzinger]

Originally Posted by poiu

if I can cover the rope,

There are other options but tedlar tape is really good stuff - North uses it as their very best 'taffeta' to protect sails.

https://www.fastenal.com/products/details/0607843 . . . .
The other main option(s) are various types of heat shrink - the key is black color - most UV resistant. There are some 'abrasion resistant' variants but I dont know how good they are, never tested them.

[poiu]

Originally Posted by estarzinger

There are other options but tedlar tape is really good stuff - North uses it as their very best 'taffeta' to protect sails.

https://www.fastenal.com/products/details/0607843 . . . .
The other main option(s) are various types of heat shrink - the key is black color - most UV resistant. There are some 'abrasion resistant' variants but I dont know how good they are, never tested them.

Thanks!

[Dockhead]

Originally Posted by poiu

Thanks for this. I have spoken to John in the past and he was helpful, but he couldn't help with a full re-rig. Dyneema rigging can't do the discontinuous rigs in big sizes. I don't understand why. I put it down to not enough market to justify the risk in developing it, but I don't know.

I agree lighter rigs are great, especially in racing boats or especially dinghies. I am doing it as part of an exercise in diet all round, plus there are other big advantages. No isolators. They cost nearly $4000 on my boat and I'm not sure I can even buy them now as Navtec are bust. I'm hoping with the fact that I can unload the rig when in the dock or storage that I can get a really long life out of it.

I'm not sure I can reduce the windage though anywhere without removing the bimini and going for a roll up dinghy instead of one on davits, compromises I'm not ready to make.

Don't you have in-mast furling, like I do? I'm not sure you're going to see a huge difference in weight aloft, as a % of total, with a rope backstay, with so much weight aloft in the form of the heavy section mast and furling foil. We are already screwed, in the weight aloft department, I think.


I have faced the same SSB antenna problem and I'm going to try (when I get around to it -- it's not at the top of my list right now) NON-insulated backstay as an alternative to my parallel backstay. It's supposed to work very well -- sometimes. If that doesn't work, you can always insulate just at the top, halving the investment in those absurdly expensive insulators at our size. The bottom insulator is only needed to keep people from getting shocked from touching the backstay while you are transmitting. There are other, and much cheaper ways to deal with that.


In my opinion, getting your dinghy out of davits will have a far greater affect on sailing performance than any of these other things. Best thing I ever did for my boat's upwind sailing performance was getting rid of the large console-steered RIB which could not be handled except by jumbo davits, and the massive electrical davits needed to hoist it, going to a folding-transom light RIB, which stores out of the way on the foredeck in its bag, not interfering even with the self-tacking staysail and not causing any windage at all. On short calm weather passages this RIB can be hoisted in my new smaller, far less windage, far less troublesome, hand-cranked davits. It is less seaworthy and less capacious, it is true, but it is seaworthy and capacious enough for my purposes (5 people and groceries in reasonably calm weather), and the difference in ease of handling is immense.

And if your boat is "on a diet", you will also save a whole lot of weight. All that weight hung way out at the end of the boat is also very bad for pitching and trim.

[Paul Elliott]

Originally Posted by Jesse

You have an interesting project. The only problem that I can see is the possibility of snapping the copper core if the antenna is attached to the masthead. due to the creep of the Dyneema. A loop or coil in the antenna wire once it exits the back stay core might handle that but loops and coils detract from an antenna's performance. You've a great idea here please keep us posted.

Copper wire almost certainly has more creep than Dyneema, so I doubt that the antenna wire would be broken by a little elongation. Also, a *small* loop or coil will have little effect in a backstay antenna, since the slight bit of inductive reactance will be compensated by the antenna tuner. In any case, you should include enough extra length in the wire after it exits the Dyneema to allow for backstay adjustment, and this extra will need to be dressed so as not to snag anything when the backstay is tensioned down.

[poiu]

Originally Posted by Dockhead

Don't you have in-mast furling, like I do? I'm not sure you're going to see a huge difference in weight aloft, as a % of total, with a rope backstay, with so much weight aloft in the form of the heavy section mast and furling foil. We are already screwed, in the weight aloft department, I think.


I have faced the same SSB antenna problem and I'm going to try (when I get around to it -- it's not at the top of my list right now) NON-insulated backstay as an alternative to my parallel backstay. It's supposed to work very well -- sometimes. If that doesn't work, you can always insulate just at the top, halving the investment in those absurdly expensive insulators at our size. The bottom insulator is only needed to keep people from getting shocked from touching the backstay while you are transmitting. There are other, and much cheaper ways to deal with that.


In my opinion, getting your dinghy out of davits will have a far greater affect on sailing performance than any of these other things. Best thing I ever did for my boat's upwind sailing performance was getting rid of the large console-steered RIB which could not be handled except by jumbo davits, and the massive electrical davits needed to hoist it, going to a folding-transom light RIB, which stores out of the way on the foredeck in its bag, not interfering even with the self-tacking staysail and not causing any windage at all. On short calm weather passages this RIB can be hoisted in my new smaller, far less windage, far less troublesome, hand-cranked davits. It is less seaworthy and less capacious, it is true, but it is seaworthy and capacious enough for my purposes (5 people and groceries in reasonably calm weather), and the difference in ease of handling is immense.

And if your boat is "on a diet", you will also save a whole lot of weight. All that weight hung way out at the end of the boat is also very bad for pitching and trim.

I should save about 35 kg with the fittings and isolator included. You are correct, it is not a big percentage of the rig weight as I do also have a heavy roller furling mast. Maybe the mast and rigging weighs 1000kg, so 3.5%. But I can also save 20kg with a new furler mechanism and maybe 30 kg with new sails. A bit from dyneema halyards/sheets and you are nearly at 10%. The thing is, it is justified in a number of ways. Weight, cost and longevity.

Another advantage of the backstay being in dyneema is a lot of the weight is high up, so it's impact is proportionately greater than it would be with a lightening of the shrouds, where the wire thickness drops markedly with height.

I'd love to ditch the davits and dinghy, but for my type of sailing a much enjoyed luxury is having a comfortable, dry and powerful dinghy in davits and I would like to give it up a lot less than I would like to keep it, so it stays. I often do multiple mile runs several times daily. It means anchoring in the sticks can be enjoyed without inconvenience. I launch and hoist the dinghy every day, so it needs to be deployed easily. I have downsized the dinghy and outboard recently and lost another 60 kg. That was a good move, but now it is on the edge of only just big enough.

[Dockhead]

Originally Posted by poiu

I should save about 35 kg with the fittings and isolator included. You are correct, it is not a big percentage of the rig weight as I do also have a heavy roller furling mast. Maybe the mast and rigging weighs 1000kg, so 3.5%. But I can also save 20kg with a new furler mechanism and maybe 30 kg with new sails. A bit from dyneema halyards/sheets and you are nearly at 10%. The thing is, it is justified in a number of ways. Weight, cost and longevity.

Another advantage of the backstay being in dyneema is a lot of the weight is high up, so it's impact is proportionately greater than it would be with a lightening of the shrouds, where the wire thickness drops markedly with height.

I'd love to ditch the davits and dinghy, but for my type of sailing a much enjoyed luxury is having a comfortable, dry and powerful dinghy in davits and I would like to give it up a lot less than I would like to keep it, so it stays. I often do multiple mile runs several times daily. It means anchoring in the sticks can be enjoyed without inconvenience. I launch and hoist the dinghy every day, so it needs to be deployed easily. I have downsized the dinghy and outboard recently and lost another 60 kg. That was a good move, but now it is on the edge of only just big enough.

Well, if you are going to take this to its logical conclusion, you will need a new slender carbon mast with full batten roachy carbon laminate main.

Now THAT you will certainly feel.

As to the dinghy -- I never suggested getting rid of davits altogether. I only suggested a dink which can be folded up on the foredeck for longer passages. I agree that when you're gunkholing, you want an instantly deployable dinghy, and that means davits. But the lighter dinghy is much easier to handle on davits, too.

I have already done the dyneema halyards and sheets, and the carbon laminate sails (from your sailmaker -- thanks again for the introduction). I can't feel the difference in weight aloft, but the sails of course transform the boat.