Ganzi 7 Posted January 25, 2015 Share Posted January 25, 2015 I have to change the rigging on my 34 ft trimaran (aluminum mast, classic glass sandwich) and am interested in textile (weigh saving, ease of handling). But I am concerned that I will introduce new stress in the attachments and possibly in the structure - ever ripped a cleat by tying up using a segment of halyard instead of proper stretchy mooring line ? So, it seems that I should go for a fiber that has the weight of high-tech stuff but the elasticity of steel. Any suggestion ? Link to post Share on other sites
southerncross 3,901 Posted January 25, 2015 Share Posted January 25, 2015 http://www.colligomarine.com/ Link to post Share on other sites
Ganzi 7 Posted January 25, 2015 Author Share Posted January 25, 2015 Actually, SC, that 's where my question came from. "sized for equivalent stretch so you will get the same performance"stretch = elasticity ? Link to post Share on other sites
southerncross 3,901 Posted January 25, 2015 Share Posted January 25, 2015 Actually, SC, that 's where my question came from. "sized for equivalent stretch so you will get the same performance" stretch = elasticity ? There have been a few threads on the various synthetics available with differing opinions on creep and stretch. I guess you probably already understand that you'll need a larger diameter synthetic to get similar strength to a smaller diameter metal. Have you written to the guys at Calligo? They're usually very helpful. And they seem to have a lot of experience with multihulls. My big concern was also the additional loading it takes to get tension. It was suggested I would have to beef up Bulkheads. Not worth it in the end. But maybe for you. Keep us posted. Link to post Share on other sites
jayson 7 Posted January 25, 2015 Share Posted January 25, 2015 Don't know about stretch , maybe slight creep , once the lines are bedded in (splices pull up ) I don't think these much movement. I'm looking at running Dynex dux 75 and have done some research and talked to some people who swear by it. It's cheap once you factor in all the terminals , swages , adjusters needed for wire. It's lighter and you can splice it yourself . Link to post Share on other sites
Rantifarian 7 Posted January 25, 2015 Share Posted January 25, 2015 Actually, SC, that 's where my question came from. "sized for equivalent stretch so you will get the same performance" stretch = elasticity ? Two sorts of stretch are important for standing rigging, the usual stretch you get in everything, measured using modulus of elasticity, and creep. Creep is slow deformation under load, basically a lot of the synthetics start to relax a little if they are kept constantly loaded like in a sidestay. The guys selling the stuff, like collegio, will know what diameter increase to go for so this isn't an issue for you. It will still be lighter than stainless Link to post Share on other sites
Trovão 510 Posted January 27, 2015 Share Posted January 27, 2015 Lighter, ok. But doesn't bigger diameter also mean bigger drag? Link to post Share on other sites
Rantifarian 7 Posted January 27, 2015 Share Posted January 27, 2015 Yes, more aero drag. Whether the tradeoff is worthwhile is up to you to decide Link to post Share on other sites
Waynemarlow 138 Posted January 27, 2015 Share Posted January 27, 2015 I always thought that the likes of Dux 75 is actually stronger comparing similar diameters to wire, the increase in diameter is purely to prevent excessive elasticity ie going bigger in diameter means the length changes less under tension. Certainly using D12 on my F16 was a real pain as constantly I had to adjust the tensions. Eventually I went to a wire forestay and slightly under size side stays ( the elasticity is pulled out under tension to almost max ) which seemed to work. On a multi where the side stays tensions are changed each time you fold or unfold and you have an easy method of adjusting the length then that may not be such a problem. Weight wise is it probably a 1/3rd of wire. Certainly for every other part of the boat, these new synthetics are the biz. Link to post Share on other sites
Ganzi 7 Posted January 28, 2015 Author Share Posted January 28, 2015 Yes, in my case, the shrouds & running backstays are tensioned by tackles, I adjust them frequently based on the tension of the waterstays. So, creep is not an issue.But I DO want to keep some stretch (elasticity ) to absorb the shocks instead of the structure. It seem that if to get that, I would have to go for a diameter smaller than what is usually recommended (and get closer to the working load limit ?).Anyway, I am going to check with the vendors. BTW, regarding drag, not that I care, but I heard that smaller rig lines diameter might actually generate more drag, because they enter in vibration and create flow disturbance. Link to post Share on other sites
lesburn1 0 Posted January 29, 2015 Share Posted January 29, 2015 I've been looking into this Excel D12 Max 78 12 strand Dyneema To re-rig my A-Cat. I have been using NER 3mm HTS 90 Single Braid for three years and think it's time for a fresh set. http://www.marlowropes.com/leisure-marine-products-1/dinghy-windsurfing/excel-d12-max-78.html Link to post Share on other sites
Lat21 31 Posted January 29, 2015 Share Posted January 29, 2015 I just upgraded a J125 to carbon rigging (from Hall) from 14 year old SS rod rigging. It has a signicantly smaller diameter than the rod rigging. I'm agree with Marlow. I have heard from others who have upgraded and the new rigging is usually smaller diameter. Most of the modern synthetic rigging materials are thinner for similar or greater strength. If you put on a thick cover, that may account for the additional diameter. After our first regatta at Key West with the new rigging, we split a forward ring frame. Not entirely sure it was due to the new rigging but we've sailed two BBS with rod rigging, higher winds and similar back/check stay loads with no problem. So Ganzi, you are right to take the lower stretch into account. But if you want the most performance, stiffer is better so we are going to repair the ring frame to make it a bit stronger and feel pretty good about the performance of the carbon rigging. We kinda sucked at Key West, but that was due to other issues. When the wind finally got over 15 our performance seemed good. Link to post Share on other sites
neuronz 33 Posted January 29, 2015 Share Posted January 29, 2015 Basically there are two values to pay attention to when sizing fiber rigging: 1. breaking load. the new shrouds need to have the same breaking load. when replacing wire the fiber is usually stronger for the same diameter. 2. stiffness. you want the new shrouds to have at least the same stiffness as the old wires, which means the product of young's modulus and cross section area E*A has to be the same. This usually means that your diameter increases, when you are replacing wire with dyneema or kevlar as these fibers have a lower modulus than steel. If you are upgrading to PBO or carbon the diameter decreases as their modulus is higher. (3.) In addition to these you also have to consider creep under static load when using dyneema. creep can be mostly avoided by keeping the load below a certain load limit (for example 25% breaking load). So a bigger diameter might also be selected to prevent creep. Always pay attention to what the mechanical properties refer to. if they refer to the material itself you have to make an allowance for fiber misalignment due to the braiding and voids within the rope. Link to post Share on other sites
crashdog 189 Posted January 29, 2015 Share Posted January 29, 2015 Good post neuronz, particularly the mech prop comment. I wonder if the numbers given on Dux account for the orientation and weave offset of the braided line? I am sure things have been worked out, but I still wonder what the real 90 number. It would be good to look at the differences between a filament tow and a braided line of equal dimension. Difficult to do for Dux, given the heat set requirement, but doing this with SK75 would at least provide a comparison base. Does anyone provide a dyneema filament rigging solution? Perhaps it would not be that much different in price as to PBO / Carbon, with complications in termination, etc. Link to post Share on other sites
Speng 8 Posted January 29, 2015 Share Posted January 29, 2015 Actually, SC, that 's where my question came from. "sized for equivalent stretch so you will get the same performance" stretch = elasticity ? Yes stretch = elasticity. If you size it that way it's way stronger than you need. Regarding creep that's mostly a function of pre-tension, dock tune, whatever you call it. I reckon most multi rigs don't have much of that relative to a typical racing mono so not as much of an issue. Talk to Colligo, they can either help you out or put you in contact with a knowledgeble rigger who can. From what I can see the stuff is great value for money. Link to post Share on other sites
southerncross 3,901 Posted January 29, 2015 Share Posted January 29, 2015 Coincidentally from the front page ... Last weekend welcomed the Orange Crush to the San Diego Racing scene. The New F32SRXC, Jail Break (long story about build issues) beat everyone in the fleet in the Cabrillo Series by at least 8 minutes! In light air! Fully rigged with Colligo Dux rigging screecher and spinnaker furlers, Jerry Fiats boat is the boat to watch for now ... Link to post Share on other sites
neuronz 33 Posted January 29, 2015 Share Posted January 29, 2015 Good post neuronz, particularly the mech prop comment. I wonder if the numbers given on Dux account for the orientation and weave offset of the braided line? I am sure things have been worked out, but I still wonder what the real 90 number. It would be good to look at the differences between a filament tow and a braided line of equal dimension. Difficult to do for Dux, given the heat set requirement, but doing this with SK75 would at least provide a comparison base. Does anyone provide a dyneema filament rigging solution? Perhaps it would not be that much different in price as to PBO / Carbon, with complications in termination, etc. I think you can probably use the difference between solid steel and wire as an estimate of braiding effects. shouldn't be too hard to find those values for wire. There are some products where the braiding is reduced to the minimum (i.e. maffioli ultrawire) to reduce the fiber misalignment. I have seen dyneema filament rigging, but as you say the only difference to dry carbon/PBO is the core material then which takes away most of the cost advantage. Link to post Share on other sites
Ganzi 7 Posted January 30, 2015 Author Share Posted January 30, 2015 So, I spoke to Colligo (accessible and helpful). The model I came up with (I hope I am correct) is: Fibers are stronger than steel, but they are more elastic.To replace a steel rig with fiber, for the same breaking load, you would need a smaller diameter... ... but then, you would have too much elastic stretch.Therefore, a bigger rope is used, to keep stretch low. Obviously, I had the (wrong) perception that exotic fibers would be quasi-unelastic. I keep hearing (and experiencing) super-stiff carbon laminates, halyards with no perceptible creep... This is where I got this idea, I guess. Link to post Share on other sites
Speng 8 Posted January 30, 2015 Share Posted January 30, 2015 So are you done trying to talk yourself out of it? In my mind the only question I have about Dyneema rigging on multis is whether to do the diamonds and forestay in the stuff. Link to post Share on other sites
dorian29 0 Posted January 30, 2015 Share Posted January 30, 2015 textile rigging is most of the time bigger in diameter than steel because of it's very light weight( less true for PBO) , the difference in strengh of textile vs steel is a strengh / weight ratio. they have a bigger elasticity than steel but the biggest problem is creep . the best textile rigging is carbon epoxy rod . no creep , small diameter . approx. 300Kg for 1MM2 . and the carbon with high modulus are less resistant in traction than the HR carbon. not necessary to use expensive carbon. the best are carbo link or southern spar. Link to post Share on other sites
Rantifarian 7 Posted January 31, 2015 Share Posted January 31, 2015 Those carbon rods are still more expensive than dyneema, and I thought most had handling difficulties Link to post Share on other sites
Gregzore 2 Posted February 1, 2015 Share Posted February 1, 2015 Good discussion here. An important point to remember and think about with synthetic rigging is not just the load, but the type of loading. Is the loading mostly static due to preload (diamond tensioners, water stays), or is it dynamic (running back stays). Different fibers are better suited to these two very different applications. The different rope fibers have very different performance characteristics. For example, creep is a significant issue with HPE (dyneema/spectra) fibers while creep is a non-issue with aramid fibers (kevlar). On the other hand, dyneema and spectra fibers can be braided into a rope which has good performance in bend-over-sheave while aramid fibers tend to have a lot of internal abrasion when they are braided. Carbon on the other hand is an excellent option for preloaded static loads (as is fiberglass), but it is terrible for repetitve bend over sheave applications. The key is to select the best suited fiber for each individual application. A little thought about the type of loading and each fiber's strong and weak points should be more than enough to make good choices. The only real drawback to all of the synthetics is that they are all much more susceptible to abrasion than stainless steel wire. This factor is very difficult (if not impossible) to get around. Link to post Share on other sites
Ganzi 7 Posted February 3, 2015 Author Share Posted February 3, 2015 Speng,Diamonds: I decided against: chafing against spreaders, difficult (and critical ?) to check / adjust tension. Forestay: AFAIK, if furler, dyneema is out of question (chafing, inspection, montage). And that's a pity since I believe this is where big weights gains can be made. Considered going back to the simplicity of a hanked jib, but realized that the furler is part of the requirement when sailing with the family. BTW, the weight of my steel rig (just the cables, no attachments/bottlescrews....) forestay 4 kg (w/o foils), capshrouds 9kg, running backstays 4 kg, diamonds 9 kgs. Link to post Share on other sites
Merit 25 4 Posted February 3, 2015 Share Posted February 3, 2015 I always thought that the likes of Dux 75 is actually stronger comparing similar diameters to wire, the increase in diameter is purely to prevent excessive elasticity ie going bigger in diameter means the length changes less under tension. Certainly using D12 on my F16 was a real pain as constantly I had to adjust the tensions. Eventually I went to a wire forestay and slightly under size side stays ( the elasticity is pulled out under tension to almost max ) which seemed to work. On a multi where the side stays tensions are changed each time you fold or unfold and you have an easy method of adjusting the length then that may not be such a problem. Weight wise is it probably a 1/3rd of wire. Certainly for every other part of the boat, these new synthetics are the biz. http://www.marlowropes.com/leisure-marine-products-1/cruising-racing/d12.html You need to use heatset prestretched dyneema. Sk78 would work for runners or other lines adjusted on a tack to tack basis, but not something as static as shrouds. Dux or HTS 75 from new england is what you want. Link to post Share on other sites
Mikey Don’t Like Sh*t 97 Posted February 3, 2015 Share Posted February 3, 2015 I've been looking into this Excel D12 Max 78 12 strand Dyneema To re-rig my A-Cat. I have been using NER 3mm HTS 90 Single Braid for three years and think it's time for a fresh set. http://www.marlowropes.com/leisure-marine-products-1/dinghy-windsurfing/excel-d12-max-78.html I've been using this for almost 2 years on my A-Cat. Love it. So far, I've supplied it to another 10 or so A-cats. Works perfectly, at roughly the same cost as wire, but weigh's less than 1/4 the weight of the wire rigging. I have 3 orders in the bin for new a-cats to finish up this week Link to post Share on other sites
glowmaster 0 Posted February 4, 2015 Share Posted February 4, 2015 I am splicing up a new set of shrouds for my tri with New England HTS 75. Anybody have a rule of thumb how much constructional stretch to allow for in the two brummels before I load them? thanks ed Link to post Share on other sites
Speng 8 Posted February 5, 2015 Share Posted February 5, 2015 I saw something on this but I forget where but I reckon the horse's mouth in this case is NER (i.e. the rope manufacturer) Link to post Share on other sites
Speng 8 Posted February 5, 2015 Share Posted February 5, 2015 Speng, Diamonds: I decided against: chafing against spreaders, difficult (and critical ?) to check / adjust tension. Forestay: AFAIK, if furler, dyneema is out of question (chafing, inspection, montage). And that's a pity since I believe this is where big weights gains can be made. Considered going back to the simplicity of a hanked jib, but realized that the furler is part of the requirement when sailing with the family. BTW, the weight of my steel rig (just the cables, no attachments/bottlescrews....) forestay 4 kg (w/o foils), capshrouds 9kg, running backstays 4 kg, diamonds 9 kgs. Interesting... would love to see pics when it's all done. There was some discussion around here or maybe on Gear Anarchy about furling on a synthetic forestay. You might want to talk it over with Colligo if you haven't already but it might require new hardware which is probably a no go for you. You could probably take 9 kilos out of your rig which is pretty nice. I think for the runners you can get by sizing them for strength (so they end up being smaller than if you size them for stiffness) and as one of the above posts mentioned you might choose a different kind of rope. Link to post Share on other sites
groper 0 Posted February 5, 2015 Share Posted February 5, 2015 We've rigged our 40ft cruising cat with Dux. Everything is synthetic except the forestay for use with a roller reefing furler. If I had unlimited funds, I would have used a structural furler and torque rope for a forestay... So far the diamonds have not been a problem using Dux. There is a little slackening of the ropes as they settle in, had to retention everything about 3 times before it all stops moving. After that, it's no different to wire really in terms of day to day usage. Won't be long until everyone is doing it Link to post Share on other sites
ease hike trim 19 Posted February 7, 2015 Share Posted February 7, 2015 I am splicing up a new set of shrouds for my tri with New England HTS 75. Anybody have a rule of thumb how much constructional stretch to allow for in the two brummels before I load them? thanks ed You know that's an SK75 product, correct? Link to post Share on other sites
glowmaster 0 Posted February 7, 2015 Share Posted February 7, 2015 I am splicing up a new set of shrouds for my tri with New England HTS 75. Anybody have a rule of thumb how much constructional stretch to allow for in the two brummels before I load them? thanks ed You know that's an SK75 product, correct? I do, isn't it the same SK75 as Dynex Dux?, which is what is replacing. Link to post Share on other sites
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