Swallow Yachts Association

Swallow Yachts Forum => Technical => Topic started by: globetrot on 27 Aug 2023, 08:54

Title: Friction on mast from jib halyard tensioner shackle and block - BR20
Post by: globetrot on 27 Aug 2023, 08:54
BR20 - traditional sloop with no spar

I'm noticing that the end of the jib halyard tensioner that attaches to the mast base, just above the step rubs on the mast. The friction is so great that eventually serious damage will be done to the mast. This issue is brought on by the fact that the halyard tensioner is parallel to the mast and especially when under pressure, the block and parts of the shackle press up agains the mast.

The problem is even more concerning because my mast is carbon fiber and not fit for this kind of wear.

Is anyone else experiencing this issue?

Does anyone have suggestions on how to prevent this issue?
Title: Re: Friction on mast from jib halyard tensioner shackle and block - BR20
Post by: garethrow on 27 Aug 2023, 13:35
I haven't noticed this type of wear on my mast, but will have a good look next week!

Gareth Rowlands
grp BR20 Halen Y Mor
Title: Re: Friction on mast from jib halyard tensioner shackle and block - BR20
Post by: RogerLennard on 27 Aug 2023, 17:33
Hello,
I've just taken this shot from a video I had of my jib tensioner. It looks like the metal parts are not in contact with the mast.

Best regards

Roger
Title: Re: Friction on mast from jib halyard tensioner shackle and block - BR20
Post by: Graham W on 27 Aug 2023, 20:19
My boat doesn’t have a jib halyard tensioner, which must be a later development.  However, comparing Roger’s photo with Globetrot’s, it looks like getting rid of the lower shackle and attaching the lower block directly to the lacing eye would solve both problems.  It would involve a bit of disassembly and reassembly of the block head and would end with the block rotated through 90°.  When disassembling, it’s very easy to lose the little black plastic spacers!
Title: Re: Friction on mast from jib halyard tensioner shackle and block - BR20
Post by: globetrot on 29 Aug 2023, 00:30
Hello,
I've just taken this shot from a video I had of my jib tensioner. It looks like the metal parts are not in contact with the mast.

Best regards

Roger

Thank you Roger, especially for the photo. Your solution seems like it does the trick.

In a pinch I also came up with another solution. I replaced the D-shackle with a twisted D-shackle so now the block isn't poking its pointy bits into the mast. An additional advantage is the jib halyard tensioner remains a removable piece of equipment, which is preferable when de-rigging.
Title: Re: Friction on mast from jib halyard tensioner shackle and block - BR20
Post by: RogerLennard on 30 Aug 2023, 18:59
Just one extra thing... I made this 'boot' for the lower parts of the mast. The idea was that it would keep the ropes tidy and out of the elements, when the boat is in the boat park. It also stops the ropes and metal parts from flogging against the mast. It seems to do its job well.
Title: Re: Friction on mast from jib halyard tensioner shackle and block - BR20
Post by: globetrot on 21 Sep 2023, 23:19
To hope close out this topic, I wanted to do a follow-up to my original post. I've made a few modifications to help alleviate the friction on the carbon-fiber mast. Remember, I wanted to ensure the jib halyard tensioner remained easily detachable, so I added a Wichard self-locking twisted shackle and replaced the stock RWO double block with a harken carbo block with softer edges and no metal parts touching the mast. I'm still not 100% satisfied, but I am no longer concerns about a hole being gouged into the mast.
Title: Re: Friction on mast from jib halyard tensioner shackle and block - BR20
Post by: Willie The Rut Lander on 22 Sep 2023, 15:49
Hi globetrot
Perhaps a soft shackle would be inexpensive and kind to your mast.
Willie
Title: Re: Friction on mast from jib halyard tensioner shackle and block - BR20
Post by: globetrot on 22 Sep 2023, 16:25
Hi globetrot
Perhaps a soft shackle would be inexpensive and kind to your mast.
Willie

Yes, I was thinking of adding this. Thank you.