Jib halyard failure

[Philip Wherry]

Having fun learning the art of N12 sailing in no. 3454, Jammy Dodger (Nigel Waller Final Chapter), which I  purchased earlier this year. 

Unfortunately, I'm also having some problems with chafing on the jib halyard... The previous owner had renewed it recently so it was in good condition, but it failed at or around the halyard block after . No harm done, save for the race result, but I suspect there is a systematic issue I need to fix. 

I'd really appreciate others' thoughts on possible causes and/or solutions so we can get back on the water. A few ideas / questions to start with:

- The dyneema halyard that failed seemed quite small (3mm).  Is that normal N12 spec for a carbon mast?

- I see wire N12 jib halyards for sale on P&B, which I imagine would be more resistant to chafe, but I can't see it working with the mast design (the halyard emerges from a small slot on the side of the mast just above the gate, which is just big enough to admit a small loop of rope to attach to the tensioner.  I'm assuming therefore the wire halyards are for aluminum masts (as on e.g. a 420). Is that right?

- I inspected and replaced the halyard block and all looked fine there. No obvious sharp edges and it ran nicely. However, there did seem to be some kind of carbon sheave on the inside of the mast at the position of the block.  I've no idea as to its purpose (sidewards support to the block, maybe?), but it seemed to have some play in it and may be the offending part.  My next plan is to try to inspect with an endoscope, but in the meantime, does anyone know what this might be from a design point of view and/or how to fix it.  Obviously I want to avoid buying a new mast!

Thank you!
Philip

#3454 Jammy Dodger 

[grazz]

Hi Philip

Glad you've been enjoying the 12.

National 12 jib haylards would normally be wire with a dyneema or twisted strand rope tail. We use wire haylards on carbon masts also. The wire usually has a long loop in it allowing it to pull through the slot in the side of the mast.

Can you post a photo of your set up - a photo of the sheave at front of the mast and the the slot and whatever the cleat / fixing system is at the based of the mast. That should help us work out the problem

Happy sailing

Graham

[Philip Wherry]

Graham,

Thank you for getting back to me and for the advice.  I can see how that set up would work now (and that might be the simple explanation for the chafing, if it was originally designed to work with wire).  

As you suggested, I've attached pictures which show both the sheave and set up at the base.  The latter is a bit of mess of lines, but hopefully illustrates it well enough. The current set up has the halyard emerging from the slot above the mast gate, then passing through the gate where the loop in the halyard is hooked onto the tensioner on the mast step. If you've any other ideas, please let me know!

Thanks,

Philip

[Philip Wherry]

And in case this is useful to anyone else doing this in future...  We did manage to fit a new wire N12 halyard in the end, but only after making it up around the sheave box (as the ferrule on the soft eye was too large to thread through).