Has the time arrived for synthetic rigging?

Hi all,

it looks like synthetic rigging is becoming more and more common in the yachting world. Have the time now arrived for beachcats also to go synthetic?

For our boat I am serious about using synthetic for all stays but keep the diamonds in SS wire.

Earlier it was suggested to keep some SS wire for the sections wrapped around the mast when rotating the mast. Still valid?

I have seen Colligo Marine referenced and SK78Max as one line option. Others?

Anybody with experience or opinions?

Been there and done that, it has so many advantages that it should be a no brainer, easily spliced, widely available, lighter in both guage and weight, easy on the hands and body when you end up crashing into it and the list goes on.

The one downside is that I could not ever halt the very slight creep over time. Its very little but never the less I had to adjust the rigging every time I used the boat and by consequence just couldn't get the boat settled to one constant rig setting.

Sadly I gave up and now have gone back to steel rigging.

What kind of fibers did you use and what size?

At the time ( which was a about 4 years ago ) the Marlow D12 was about the only real high strength available, but in theory absoluteley fitted the brief. I used 4mm all around but in hindsight I should have gone down a size to 3mm which may have stopped some of the creep. I notice to that you can get this D12 now in pre streteched form so maybe it is worth a go.

D12 is one of those ropes I find totally indespensible, you can do almost everything on a boat with it, from soft shackles to main sheet ( in the cascade system ) to the spinny retrieve where it is soft enough that it never seems to burn the spinny no matter how hard you try.

Thanks!

I heard referenced to size for creep and not strength. So 5mm Dux75Max (that is pre-stretched Dux75) was suggested for a beachcat. Does that make sense in your opinion?

5mm really touches on being aerodynamically brick like. To be honest why change from steel, its very well proven, you could use 2.5mm if you want, widely available at relatively modest cost, easy to rig and to be honest weight shouldn't be a problem ?

I wasted a good few weeks titavating about to simply get easily adjustiable rigs, in hindsight they were very wasted weeks.

Steel is heavy exactly where I dont want weight. I would also like to make the stays myself.
On the Tornado I belive we had 4mm dyform wire. Not far from 5mm..

How big is the drag vs reduced weight, and how to quantify the advantage/disadvantage for each option? I believe the added leverage in the rig when sailing in any kind of waves reduces the propelling force far more than the drag subtracts from the propelling force. But I am unable to quantify this.

Anybody?

My main concern would be about the synthetic stuff being cut or frayed and then breaking while I'm out racing. My steel stay wires are not that heavy in the first place and I like not having to worry about stretch or breakage, especially when I leave the boat with the mast up for a month or more.

Would synthetic wires break more often on beachcats compared to larger multis like Farrier trimarans, or 60 foot tris?
I dont think so

My nightmare is when you leave your beach cat alone overnight and some clown with a knife or a cigarette lighter comes by...

The bigger boats are usually kept at more secure locations, and they save more weight up high as their wires weigh quite a bit more. I think my steel stay are thinner than 3mm, so the synthetic stuff would add drag up high, right? Is that better or worse than a few oz. of weight?

Would that guy take the same knife or lighter to the trampoline or whatever? I dont know. Around my area boats are most often left alone.

I am willing to trade that risk against some performance

You live in a better place, no doubt! Here in Florida you can't leave ANYTHING outside over night, or you risk losing it if it's small enough to be hauled off, or damaged, if it's in a public spot.

There have been many guys who have found cigarette burns on their tramps the next morning at a public beach regatta.

I leave my boat at the club and dont worry about it. No fences at the club, mainroad to the town passes 100 meters from the lot. Pedestrian road passes almost through the club. Except from kids who wants to jump on the "trampoline" and one incident where we either lost a locking pin or somebody removed it. There have been no man-made issues with our boats there at least.

Resale value for a stolen cat in the domestic market would be nil.

Perhaps you should relocate to this place and begin flying for SAS


Other concerns or thoughts about synthetic rigging? How about the drag issue Wayne mentioned with 5mm stays instead of 2.5/3mm?

you should not forget the dynamic elasticity difference with dyneema and wire. You will notice that the boat feels softer if you change to dyneema.

As a good example, the M2 class changed from unidirectional wound aramid side stays to PBO and within one regatta they noticed that the chainplates were pulling out of the deck on almost all boats... the PBO was transfering the loads much more directly and hence the issues...

I'd be opposed to changing class rules. Change just creates dissent and ill-will.

Wait a sec Macca, I thought PBO was also a fiber, but much less elastic than aramid?

What would you recommend as a budget solution for fiber rigging on an F16 to be sailed by a 102kg crew (102kg + equipment/clothes)?

Aaaaand.... What are you currently filling your time with? Still sailing? Boating business or something completly different?

Did you post to the wrong thread Pete? I see no changes to class rules to implement fiber based rigging?

No, all these discussions usually lead to talk of rules changes. Sorry, guess I jumped the gun.

I'm satisfied with my equipment as it is.

Aramid is much less elastic than Dyneema (although a unidirectional dyneema SK90 is pretty good these days) but PBO is really great stuff and has a very small amount of elasticity and it is a noticeable difference. We are using solid carbon on a new project now and it is a huge step up from PBO in stiffness and elasticity so we expect to see a similar gain.

For a beach cat like your F16 I think you will struggle to find anything off the shelf that is better than wire for the same diameter, but you should have a look at easy rigging if you are serious about it. Sure its more expensive than wire or rope, but its a lot better.

As for my current project.... you will all see soon enough it pretty special and will certainly make the news.

I dont mind going up in diameter and trade drag for weight reduction. I'll see if I can find uni SK90.. Starting to unravel uni carbon cloth and glue on terminals myself would be a bit too exciting I think, even if fun! What is the UV rating for carbon fibers in the sun..

Easy Rigging is noted..

Looking forward to see the announcement of the project!

its possible to make your own carbon stays, you need to pass the uni fibres inside a length of heat shrink tube and wind them around a thimble at each end, then set the thimble ends in resin and shrink tube to keep it all together.

takes a lot of patience and mucking around... in the end if you value your time then you are much better to buy from someone like easy rigging

What about breakage where the stays are rolled around the mast when tacking and jibing? Are there special techniques to handle this or was the issue overrated when "plastic" rigging was new?

I am actually tempted to try to make carbon stays.. If my more conservative building partner is up to it

as long as you make sure that the resin hard area is limited to the thimble only (you cant have the unsupported cable stiff from resin) then its fine

Hoy Macca,

do you know how they handle carbon diamond wires on masts? What is done on the spreaders to avoid chafe and breakage there?

I have to think a little about how to set up the timbles unless you have some good links. So far a mental exercise but very interesting stuff!

At least now that I hear carbon fibers slowly being introduced as rigging I am certain that synthetic stays is viable and also the way to go for the future

Any piccies out there of these carbon stays ?

The stays are fine around spreaders, but you need to make a nice piece of carbon or stainless to ensure its a larger surface than the normal wire mounting.

i have been looking for pics, but none with me.

There is another option from maffioli that could be good. its called ultrawire and can be supplied in 3, 3.5 and 4mm sizes in either SK90 and Zylon (PBO) this is a pretty good solution for you guys.

I absolutely agree with Wayne. In short Dyneema isn't right for standing rigging. With Vectran you could solve the problem of creep (pre stretching Dyneema is only marketing blabla). But compared to steel of similar diameter I don't like the softness, although I could never measure a difference in speed (I have no jib). Hence this is very to your like. With a jib I would always go with the stiffest material.
Never used PBO, Carbon or Aramid on my boat. None of them like UV and water, hence need sophisticated protection and one would lose the diameter advantage on small boats.

On small cats, rigging drag is more important than weight (cross-section area depends on diameter in square and drives strength and weight, drag depends on diameter only).
The performance difference to 2.5mm steel (for uni) is more in your mind than on the water for a small cat anyway.

Since three or four years I use synthetic ropes (dyneema) to connect the wires to the mast fitting, so that the steel wire never touches the carbon mast. Makes the boat silent as well.
Never had any failure. The boat is exposed the full season to UV and weather.

Cheers,

Klaus

Hi Klaus,

what I have observed is that our rigs move about a lot as we sail trough waves. The thinking is to reduce weight aloft to get less inertia from the rig movements and thus get more speed.
The opposite value is increased drag if synthetic materials have a bigger diameter than metal wire.
Are you able to quantify this in a meaningful way? How much will total drag increase if going from 3mm to 5mm stays. The "reduced inertia" factor can be calculated, but how to compare this... I have no clue but I have a feeling

Additional advantage could be easier righting for lightweight crews and a small degree of better righting movement.

I dont see why the jib makes a difference in metal vs synthetic rigging? Unless the rigging is really stretching and flexible the forestay will be tightened by the mainsail sheeting loads going upwind.

What is the issue with water and UV on carbon? Is carbon fibers UV degradable? Water degradable? Or are you thinking of the fittings and resins being broken down by UV and galvanic corrosion?

Hi Rolf,

a moving rigg isn't bad. Actually it has improved aerodynamics. In many dinghi classes "pumping" (e.g. periodical change of the sail inflow conditions or sail angle) if limited or forbidden, because people feel that their seems to be an advantage by doing so.
Hovever if the motion causes excessive hull drag due to splash or nose diving, it can't be good. There are many possibilities to do cure the problem: Hull shape, T-foil rudders and reducing inertia.
Reducing inertia is always good, but unfortunately the standing rigging is only small part of the mast-sail system and this is only a part of the whole boat inertia. Hence the gain by playing with lighter standing rigging is small.
Hull shape has significantly improved in the last years. For example my Javelin sails far smoother in waves than the 4 ft longer Tornado. I would expect similar or even better wave-going behaviour for the F16, becase of the lower mast and lower inertia.
The most efficient way would be a T-foil(ed) rudder. It will not only damp the pitching motion, but transfering the energy from pitching in thrust (negative drag). However in calm water you would have drag penalty.

The advantage of essier rigging is on F16 size boat fairly low. I didn't feel any difference.

The jib makes a difference: From your comment I see that we agree that a sagging jib is not good (especially upwind). If you don't have a too flexible mast the main sheet will keep the forestay tight. But when you react to a puff by opening the main your jib would start to sagg in exactly that situation where you want a flat jib.

Every rope from organic (e.g. plastic, anorganic = metal) suffers from UV and water. The question is how fast.
BTW I know of carbon fiber only used with resin, hence a rod and not a rope. So the UV and water resistance of the resin would be important. It should have some addtitional protection (e.g. PU or wax).

I guess some googleing would reveal you, that
Dyneema is good againbst UV and water (I replace the unbraided dyneema ropes on my boat only once a year), Vectran is used for tugging dipping sonars and on space-exploring vehicles, hence I would think of good resistance as well. Aramid and PBO are on the low end of the table.
I can tell you that Aramid (Kevlar) has so poor water resitance that we don't use it in our business (even not with epoxy resin and PU coating), but an aircraft has a different utilisation of course.

Regarding the drag increase due to diameter, I think I made some calculations already on this forum.
Btw is 5mm a bit much for a single hander?

Cheers,

Klaus

Hi Klaus,

nice input!

About moving rigs. I find movement parallel to the sail surface to be unvanted and not comparable to pumping. Reversal of flow can never be good in my opinion. This is the movement (pitching) I think about when discussing movement. Movement in the other axises might be good but force lost due to elasticity does not sound good on a racing sailboat unless there are handling issues.
Stays that are "flexible" to a certain degree would improve on the jib, but starting to design this into the rig is very complex and with uncertain gains in my opinion. I would prefer to pull on some more downhaul and continue running the mainsheet and accept the jib draft increase.


Agree on the T foils! But they dont seem to be "in vouge" anymore.

5mm is probably a bit much but the matieral properties would be the deciding factor.


UV should not be an issue if the fibers are protected by a heat shrink tube. Epoxy is a well known property regarding UV and water. The remaining question is how water affects carbon fibers in the long run.



Very interesting discussion. Thanks for adding to it Klaus!

Will it make righting any easier once it is wet and has absorbed water?

Moving rig due to elasticity in the stays is for sure slow. No other way to look at it, just plain slow.

The best way to reduce pitching from weight aloft is to reduce the weight The hard part is to achieve that without the drawbacks of some of the cheaper solutions.

On the topic of Vectran and UV..... its a shocker! its been a while since i used the stuff but I recall it was suffering 50% los in strength within weeks of being exposed. Its up there with PBO in that regard.

The thing to remember is that there are some really nice solutions to these problems, like easy rigging who have a nice way to seal the fibres in a watertight and UV proof cover, so the PBO from them lasts a very long time (we use X40 stays like this for more than 5 years)


Also the Maffiloi ultrawire is a good mid range solution too.

Hi Rolf,

I have been using 3mm SK-90 Dyneema for about 14 months with out any issues.
What I did learn was that you need to put in your first thimble them stretch the line before measuring and putting on the thimble at the other end.
My biggest complaint is that I can't find SK-90 in 2 or 2.5 mm!

I sorry I have not been keeping up, did you get your boats in the water?

Les

Thanks for the input Les!

Could you write a small summary of the pros/cons of synthetic rigging as you see it. A load of pictures and some tips on how to rig would also be most welcome

No boat in the water yet. Tonight I waterproofed the nuts for the beambolts. Will continue with the rear beam nuts tomorrow night. Then the main and rear deck goes on and we are full on with the accessories like rudder system, sails, dolphin striker etc.
I also worked on the Y axis of my CNC mill conversion so I do some other stuff in addition to the boat build. Every workshop of course needs a small CNC mill..

Rolf, I'll see what I can do.
RE. the CNC let's see some shots.

Les

Here is a shot of the mill itself with the completed X axis drive fitted.




Other shot is from the lathe where the base for the Y axis thrust bearings is machined. Please note the homemade boring bar which I am fairly proud over having built



Still a fair bit of work to do, but it is a lot of fun!

OK Rolf here goes.

At the mast end I use a T-Ball bail Terminal with two sailmaker thimbles. The thimbles are cut and put on the T-Ball Bail and the weld closed then sand and polish to remove any burrs. Say your T-Ball mounts on the mast at 7 meters, you would mark 16 meter of your shroud material at the half way point and then using a brummel ( http://www.animatedknots.com/brumme...og.jpg&Website=www.animatedknots.com ) fix the line to the thimble on the T-Ball Bail.


After you stretch you line, measure and put the thimbles on the ends of the shrouds, remember to orient the lines as one will want to come off the bail facing back (main shroud ) and the other facing forward (Fore stays). I also attach the trap lines to the thimbles.



I hope this helps someone.

Les

It just came to me that you F-16 guys use a single fore stay.
So you would need three thimbles. But this would make the termination a much simpler job.

Les

Thanks Les!

Nice and easy! Only complication for a home-shop would be the welding. This could be overcome by using a largish shackle to collect the stays with thimbles and mount them to the mast fitting. My mast does not have the slots for T bail terminals.

Looks very doable!

Rolf,

Do check that the cable thimble and the shackle are compatiable, the bolt eye of the larger shackle needed for 3 stays ( 4 in the case of an A Class rig )will be a tight fit through the 3mm thimble as I discovered.

The other thing I found using SK75 was that under load the Brummel knot locked it off beautifully but under very light loads with slight " jarring " effects, the knot would gradually slip through ( the rope is quite slippery and naturally oily to touch ) and eventually release ( as I also discovered ), I found that simply sewing a couple of loops through the tail section stopped this.

Do check the breaking strain as SK90 is about 1.5 times stronger than wire and you can afford to go down in diameter, I found the larger 4mm seemed to stretch /creep more than the 3mm and sort of reasoned that on first use, the smaller diameter " tightened " the weave of the new rope whereas the 4mm never seemed to really fully close the weave.

Guys,

You will 100% be slower if you make your stays and forestay with normal SK75/78/90 rope. The loss of power with the ropes is going to make a difference that you will notice.

If you dont believe me, go and try it with some straight line testing against a std boat.

Hi Macca,

what is the issue with normal SK90 rope ? The braiding?

pretty much correct. The braiding essentially puts the fibres off the direct line of load and as such they are never able to be properly aligned with the load, this also has a further effect due to the bundling of the fibres into 12 strands. there is always some space for these bundles to flex and compress which makes it more elastic.

Unidirectional fibre stays are the only way to go.

This subject has come up at Sailing Anarchy, with some of the same folks and some new thoughts on the subject.

http://forums.sailinganarchy.com/index.php?showtopic=144443

Just read through it. Seems like the consencus is that fibre rigging will be the future. Just need some development, but no prob. to go bleeding edge on a hobby basis if we want to.
I liked the carbon stays! But how would they react to being bent around the mast when the mast rotates (I assume other fibers being used there). With carbon tow it should be possible to DIY carbon stays but the handling would indeed be a challenge.




Thanks for the link.