I saw a cat rigged with Dyneema or similar cord for the stays and forestay. It was a 22 ARC, big cat. I had thought about that was concerned as to how it would perform. Any input? I am interested in using it for the Jib/forstay line on my new sails for my H16 and also considering it to replace all of the original rigging on the Supercat 17 I just picked up. It still has all the original rigging and I will need to replace it.
Thanks for any input.
Dyneema cord
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Posted: May 23, 2010 - 08:05 PM
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Posted: May 24, 2010 - 08:26 AM
if you go to this page and scroll down you will see a pic of a full set of synth rigging for the new 30-35m2 sail area f22 folding tri
http://www.f-boat.com/pages/trimarans/F-22.html
that's 50% more sail area than the 20m2 on my 17' nacra 5.2 so presumably synth rigging is entirely workable on beachcats -
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Posted: May 24, 2010 - 11:10 AM
One thing to note, if the ARC22 has a similar mast base to a SC20 it is a captive ball at the base that will not come loose unless you remove a retaining bolt. So if the line was to stretch a little the mast would not come down, the H16 on the other hand, the mast base could come out if the rigging is not tight enough. It might work great, just a bigger problem if you get stretch.
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Scott,
‘92 H18 w/SX wings
‘95 Hobie Funseeker 12 (Holder 12)
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Posted: May 24, 2010 - 11:27 AM
I doubt the dyneema would creep enough to dismast. As soon as it creeps enough that the stays are 'loose' there's not going to be any tension on it, so it won't creep stretch further on its own.
I believe dyneema creeps enough that you would have to be mindful of it and tighten it several of the first times out with it. Of course, you could always go with thicker line, but that might defeat the purpose.
FWIW I use steel.
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Rob
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Posted: May 24, 2010 - 12:20 PM
I was thinking of the creep being cause by load while sailing, not when just rigged on the beach. So after hours on the water in high load/wind conditions the line could stretch a little.
Another concern is the rubbing at the mast tang where the line connects, make sure the line does not rub on the mast or trap lines. I think this was discussed a couple months ago and people had some solutions for the rubbing etc.
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Scott,
‘92 H18 w/SX wings
‘95 Hobie Funseeker 12 (Holder 12)
‘96/‘01/‘14 Hobie Waves
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Posted: May 24, 2010 - 05:59 PM
Dyneema should be fine for rigging, it is as strong or stronger than steel if you use the proper eye splices. The nature of creep, means that dyneema won't stretch while you use it but it will over a longer period of time and under load. Do you might have to tighten your stays a couple of times over the first month. The real problem is that it will abrade relatively easily it has to be protected in areas where it rubs, this is usually line on line rubbing or near the mast connection. You can use PVC line covers taped in place in these areas. The other problem is that even with coatings it will eventually degrade in UV, so if you leave your cat rigged it is probably not a good choice. Lastly the weight savings aren't really worth the cost unless you are racing competitively. I'm the biggest sucker for high tech stuff there is and I couldn't justify the cost or downsides.
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edited by: Wolfman, May 24, 2010 - 05:03 PM
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Dave Bonin
1981 Nacra 5.2 "Lucile"
1986 Nacra 5.7 "Belle"
Winnipeg, Manitoba, Canada
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Posted: Jun 01, 2010 - 01:34 PM
But why go to the trouble? What's wrong with steel?
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Posted: Jun 01, 2010 - 02:49 PM
Exactly, the only real reason to go to dyneema standing rigging is for the cool factor OR if you have a super light rig for racing (see A-Cat). Standard stainless rigging will last indefinitely in fresh water.
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Dave Bonin
1981 Nacra 5.2 "Lucile"
1986 Nacra 5.7 "Belle"
Winnipeg, Manitoba, Canada
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Posted: Jun 01, 2010 - 04:59 PM
Obviously, though, it won't last indefinitely if you use it. It just won't corrode much from the fresh water.
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Rob
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Posted: Jun 01, 2010 - 05:31 PM
I'm not sure about that, I know you should replace rigging every 10 years or so or when you see some frays and it is good practice. But I just retired the original rigging from my 1981 Nacra 5.2 and am keeping it for spares. The only reason I replaced it was because it is from 1981 and the trap wires have a few frays, no frays that I can see on the standing rigging at all.
As long as you aren't loading the wires enough up to yeild them and you don't abrade them 'Technically' they should be the same strength as when you first got them. The reality is that the same cannot be said for the swage ends and things happen with use i.e. kinks during storage and people falling into your wires during capsize etc.
I agree that you should change your wire rigging about every 10 years in fresh water (more often in salt), simply because you reach a point where you can't know if there is a weak spot in the wire or at the swages. I guess the point is that you are likely having to replace dyneema or vectran rigging at least once a season just due to UV deterioration never mind abrasion and other problems. So IMHO it isn't worth it for the average guy.
D.
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Dave Bonin
1981 Nacra 5.2 "Lucile"
1986 Nacra 5.7 "Belle"
Winnipeg, Manitoba, Canada
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Posted: Jun 01, 2010 - 10:58 PM
Dave, it is ingenuously obvious that you have never experienced a shroud failure. If you had, you might not be making the statements that you had in your previous two posts.
Experience disagrees with your theory.
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Philip
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Posted: Jun 01, 2010 - 11:24 PM
Don't think that I am arguing that shrouds don't fail! I believe I said that they will last indefinitely (i.e. you don't know exactly how long they will last but likely beyond expections). I know they do fail and for various reasons, and no I haven't experienced this nor do I want to (hence change my lines even they aren't obviously worn except for the trap lines).
Most often they fail at the swages, at points of stress and abrasion where the lines have frayed but that doesn't mean that they can't fail due to imperfections combined with fatigue loading and minor corrosion (keeping in mind that it is stain-less not stain-proof). Hence the reason you want to replace them on a regular schedule even if they don't appear worn.
Not to mention the tendancy for wire rope to progressively fail once a strand to two is severed. This is the reason I use chain instead of thick wire rope in my ice boom designs on waterways.
The point I was trying to make is that stainless rigging is WAY more resilient than any type of hi tech line (barring some of the crazy semi rigid coated things you can get for huge $$$) even though the hi tech can have higher tensile strengths.
Compared to hi techs, stainless will last a hell of a long time barring damage. Maybe an exageration but I know of several (OK 3) 30 year old cats still running on original rigging (including my own until recently). Obviously a sane person would expect them to fail at some point relatively soon and they haven't been in the ocean ever and probably never even in what you would consider heavy air.
And I did hear of 3 big guys is Aus on a 5.8 who were out in crazy wind. They were able to hold down the boat in the gales until the shrouds were stressed beyond capacity and snapped. In this case they were able to push the boat so far that they actually exceeded the tensile strength of the wire rope (quite impressive really).
edited by: Wolfman, Jun 01, 2010 - 10:27 PM
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Dave Bonin
1981 Nacra 5.2 "Lucile"
1986 Nacra 5.7 "Belle"
Winnipeg, Manitoba, Canada
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