Synthetic shrouds and stays... on Trimarans

[Skip JayR]

Originally Posted by Stumble

Keep in mind that really high performance boats these days are switching to unidirectional carbon rod rigging. It is even lighter and smaller than synthetics, but about 10 times the price.

I really hate this carbon hype... its so stupid. Did you know, that the Carbon fibres have the same prize like Glas fibres ?? I am not joking...

The warfts sell the carbon boats, masts etc. .... as something "exclusive", and slap 150-200% extra to the regular prize. But thats all show making.

Because carbon is cool, is hip and has the image of something special and "high tech" the boat industries make dammed huge profits. Its a dirty business with the "innocent buyers", a lawyer, a dentist, a surgerist or manager who earn tons of money and easily can afford expensive yachts they have no idea about the real prizes behind. So they are exploit by the sales staff of the boat builders. A bad game. Clever marketing from boat industries over last 20 years.

The other bad part of this dirty business: Carbon cannot be recycled. "0" or as we say: Its "un-kaputtbar". You cannot shredder it and turn it into something different. A really stupid material I would say.

I am in contact with an international research team we are thinking seriously to build a boat with alternative materials which can be fully recycled, but have 100% same quality as carbon fibres. And this material will cost 40-50% of the carbon fibre, too. :-) Yet cannot talk about in details.

[Stumble]

Skip,

That rope is almost certainly not heat set, which is what you need for standing rigging. Heat setting radically changes the creep characteristics and compacts the strands, making the rope much stronger for the size. Which is pretty much required for standing rigging.

[Skip JayR]

Originally Posted by Stumble

Skip,

That rope is almost certainly not heat set, which is what you need for standing rigging. Heat setting radically changes the creep characteristics and compacts the strands, making the rope much stronger for the size. Which is pretty much required for standing rigging.

It is... on the specification list further is named:

• material: Dyneema SK75*
• HEAT-STRETCH-SYSTEM
• UV stability and
• scrub solidity.

*) In recent years Dyneema lines have become popular very fast. Not surprising, since it has very little stretch and is also twice as strong as polyester. Moreover, it is so light that it floats on water. This type of line is sometimes sold under the trade name Spectra. Dyneema has a good chemical resistance. Mechanical properties are unaffected by seawater, oil or other common chemicals. Also, the material is very durable.
Dyneema is available in three versions: SK75, SK78 and SK90 since late 2009. SK75 and SK78 are very similar in terms of features, the biggest difference is the creep (elongation under continuous high load). SK75 has a little creep and SK78 not (negligible). The SK90 variant is, as specified by DSM itself, 13% stronger than previous versions and of course lighter. Also the SK90 shows like SK75 little creep. Lines with creep are less suitable for backstays, but the amount of creep in SK75 (and SK90) is small and therefore, in addition to SK78, often this material also is used for backstays.

Dyneema fibers are smooth (self lubricating), are quite durable and have a low melting point. A good cover jacket is sometimes needed for additional protection. Sometimes an extra layer is used to ensure that the cover and the slippery core don’t slide around. Dyneema is good UV resistance. Where the line does not wear you are fine to remove the cover largely in order to spare weight (rejuvenate). This works well for example for spinnaker sheets. Splitting Dyneema: a Dyneema line gets 95% of the strength of the Dyneema core, the cover mantle appears only wear. This is the line "core in core” splice. The easiest thing to split a "bare eye" in the line and eliminate the cover.

(Source: Material & Construction - Splicing)

[out42]

For what it's worth I've had three tris, one with stainless and two with synthetic stays.

As a previous post has pointed out, the loose leeward rigging with rotating masts would make me very nervous of stainless stays purely because of the flex issues. I had no problems with the synthetics even on a 31-1D, which had a canting and rotating mast. They are also just much nicer to live with.