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So, after 6 vertical years, my mast is now down gracefully, and sitting on the pier for the winter.

 

In general, it looks good.  My shrouds and forestay terminate to a large shackle, and their eyes are tied around bronze thimbles.  
This has resulted in very little wear to the shackle.

 

The bronze eyes are about worn out though.   One is badly cracked as well.

 

Can I re-tie the eye (Dyneema Dux) of the shrouds directly to the shackle without fear of abrasion?   How do you guys handle this on your rotating rigs?

 

SApM3wB.jpg

 

CyZXlc3.jpg

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Let me start with a disclaimer: I have no first-hand experience of synthetic standing rigging. My all-steel implementation is very similar but with three extra toggles to minimize fatigue inducing bending of the wires.

 

To me the implementation shown in your photos looks really good. I would replace what is worn without changing anything.

 

Others may have wiser advice...

 

/Martin

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That's an unusual coloured Dux.

 

Dyneema is used as a anti chafe product so abrasion shouldn't be a worry.

 

But I would be very concerned about putting a heat treated dyneema around a tight radius that will exert some cyclic loading on the eye. That is setting up a possible failure point. Heat set dyneemas are straight line static application ropes and hate small radius corners and cyclic loads around them. Use non-heat treated and it's fine.

 

I'd stick to some form of thimble or low friction eye, it'll remove the cyclic loading on the dyneema. I'd also lose that Brummel splice and go to a straight up the koozer then stitched instead. Why make the shrouds intentionally weaker than they need to be. A Brummel or lock splice like that are only there to stop a the tail leg pulling out when under no load but they do also weakens the rope, a simple stitch with a nice small waxed braid does exactly the same thing but without the strength lose.

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On a side note I would have a good look at that carbo block I assume is for the jib halyard. Depending on how you tension the halyard I would think the loads are getting very close to the max fit that type when new. For static high load applications I would look at using a low friction ring instead.

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Very good!   Thank you gentlemen!   Ed - I do have a ring that can be used there rather than the carbo.

 

"Straight up the koozer!"  Thanks for that bit of advice also - I did not realize that the Brummel might reduce line strength.  Tell ya what though - That thing ain't moving!   Without the Brummel, what length of tapered tail would I need?   The same?

 

P>S.   A quick Google yields this article:   

 

http://www.chicagoyachtrigging.com/18-dyneema-break-test-final-bury-splice-vs-brummel-splice/?v=7516fd43adaa

 

I think the author believes that while a bury splice has a higher breaking strength, both are rated higher than line strength.,.,,.

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"Straight up the koozer!"  Thanks for that bit of advice also - I did not realize that the Brummel might reduce line strength.  Tell ya what though - That thing ain't moving!   Without the Brummel, what length of tapered tail would I need?   The same?

 

Glad I didn't get too technical for you there :)

 

50 times diameter and taper well. Erring longer is better then shorter.

 

There are Brummels and there are Brummels just like there is Dyneemas and there are 'dyneemas' so it's hard to give a blanket cover all statement. I just like maximising strengths when you can and in a fixed application like yours is easy to do. If it was something that flailed around a lot or gets fondled a lot then stand back as a brummel is coming thru.

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Just an update.   After much consultation in various quarters, and considering the good advice here, I replaced my shrouds with 8mm SK-75, and no thimble.  The shroud diameter is overkill for sure, negating any weakness in the very secure Brummels I tied.   I have deadmen on the side shrouds now, which are pretty sweet.

 

After several day sails in winds to 17knots, the construction stretch is mostly gone now, and I'm liking the security of having new shrouds!

 

As Always, thanks to all for your input....

 

BbeaLNx.jpg

 

GRBGNDI.jpg

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