Any Updates on Synthetic Rigging ?

[SV Quicksilver]

I've just discovered a method that can make your lifelines tension able and removable. At the terminal ends of the line place a splice eye that is larger than required, bed the end of the tail without a taper that is longer than required with part of the tail exiting the line . Under tension the bury of the line holds but without tension one can close the slice eye by pulling on the unbedded tail to take up slack ( see whoopie lines for hammock tents). Attach shackles to the splices in order to attach the dyneema line to the pelican hooks and the pulpit. This creates life lines you can drop and tighten as it stretches.

Happy sails to you...

[Stumble]

Quicksilver,

The problem with the whoopie sling is that the lack of a taper, and the exit create stress risers that significantly decrease the breaking strength of the line. If you started with a strong enough line it would probably be ok, but I haven't seen any breaking strength tests on them, so I don't know that I would trust it in a safety application.

[glenn.225]

Quicksliver and All

There was great study done by Oregon State U on splices and end connections. Found in a link eariler in the thread. It's long but a good read.

link here: http://www.osha.oregon.gov/pdf/grant...nvestigate.pdf


Their findings of the Whoopie sling were quite good, see Page 66.

The table doesn't paste well but it is very close in strength to the eye splice.

An interesting note is metal end connectors (not spliced) did not do well at all.

[SV Quicksilver]

Originally Posted by glenn.225

Quicksliver and All

There was great study done by Oregon State U on splices and end connections. Found in a link eariler in the thread. It's long but a good read.

link here: http://www.osha.oregon.gov/pdf/grant...nvestigate.pdf


Their findings of the Whoopie sling were quite good, see Page 66.

The table doesn't paste well but it is very close in strength to the eye splice.

An interesting note is metal end connectors (not spliced) did not do well at all.

Thanks for this link, ultimately there are numerous ways to work with dyneema.

[roverhi]

The problem with splices in the very low stretch Dyneema Lines is not high loads and rapid pulls, FWIU. It's the slow low tension pull that can pull these slippery lines out of a splice. That's s why the modified Brummell Splice works so well because you aren't relying on the Chineese Finger trap of the core buried in the braid to hold the splice. I wouldn't trust the whoopie splice for a lifeline.

[Merit 25]

No. The reason the locking brummel is nice for spectra is b/c when they're not underload, the slippery line doesn't come out. You can do a regular singlebraid splice and lock stitch it with the same results.

Once the load is applied to a propperly tapper bury of 72x the dia of the line, the splice will not come out. Shock loads or flogging may try to pull it out, but that's what the brummel or lock stitching is for.

[Merit 25]

Originally Posted by w32honu

Curious how anyone is handling chafe issues at the spreader ends???
Thanks

Use Dyneema Chafe Sleave from NER. Not cheap but you don't need much.

[Stumble]

Originally Posted by Merit 25

Use Dyneema Chafe Sleave from NER. Not cheap but you don't need much.

Alternatively use a size up piece of dyneema. It's the most abrasion resistant line on the market anyway.

[Merit 25]

Not sure what you're talking about?
Upsize the shroud? -> expensive, more weight, etc.
Splice another peice of dyneema line on it? -> that won't look good at all and might not fit into the spreader tip anymore.

[DeepFrz]

There was no information as to what Jean Pierre Dick was using for his soft shackle on his forestay but it broke 1/2 way around the world. I don't know if that is information you want to hear or not.

Technical Problems Onboard Virbac-Paprec 3 - Vendée Globe 2012-2013

[delmarrey]

Originally Posted by Stumble

Alternatively use a size up piece of dyneema. It's the most abrasion resistant line on the market anyway.

I would think the ends would fray, unless they got a whipping at the ends. And the same size could be used, just push it together.
But the chafe sleeves are better IMO and not that expensive.

[Stumble]

Originally Posted by delmarrey

I would think the ends would fray, unless they got a whipping at the ends. And the same size could be used, just push it together.
But the chafe sleeves are better IMO and not that expensive.

The ends of the chaff guard are buried back into the core of the line. If done properly it should be almost impossible to see where the transitions points are, and the line should make a smooth size transition. This same technique is what is used to add the chafe sleave as well.

[Stumble]

Actually I need to correct myself. The chaff sleaves from NER are now all dyneema, but instead of 12 strand they are 42 (?) strand. This tighter weave should make them even more chaff resistant than a standard 12 strand line. I haven't played with it yet, but it looks like a good product.

Just don't be too taken in. It is nothing but a 100% dyneema line with a different weave pattern.

[Merit 25]

Originally Posted by DeepFrz

There was no information as to what Jean Pierre Dick was using for his soft shackle on his forestay but it broke 1/2 way around the world. I don't know if that is information you want to hear or not.

Technical Problems Onboard Virbac-Paprec 3 - Vendée Globe 2012-2013

I'm confused on how comparing an Open 60 racing around the world is relevant in this discussion? He didn't break a "soft shackle" as you or I know it. He broke a custom made strop that can be independantly tightened to tens of thousands of pounds. And they didn't specify how the failure happened. Was it chafe related? Underspec'd? Bad batch of material? poor assembly?

[Merit 25]

Originally Posted by DeepFrz

There was no information as to what Jean Pierre Dick was using for his soft shackle on his forestay but it broke 1/2 way around the world. I don't know if that is information you want to hear or not.

Technical Problems Onboard Virbac-Paprec 3 - Vendée Globe 2012-2013

I'm not sure what that has to do with this thread? Titanium parts fail, so do stainless and brass. Especially when you race around the world non-stop.