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Old Boat, New Shrouds

Posted By: RickInMesa

Old Boat, New Shrouds - 04/19/07 05:13 AM

I am still replacing parts on my 1971 Hobie 16, and I bought some new hydraulically-swaged, marine-eyed shrouds from our forum host. They're beautiful... and they're different from the ones I removed.

These seem to be shorter, overall, than the shrouds I removed. When rigging the boat this weekend, I started with the pins through the top holes in the shroud adjusters, and pinned my forestay through the top hole in my DOUBLE extender/adjuster, which of course is attached to the bridle. With my older shrouds, I would then carefully (see next paragraph) lower the pins symmetrically until I was securely pinned through the 3rd or 4th hole from the bottom of the adjusters. What I found with the new shrouds is that the second hole from the top is about as far as I can go, before everything everywhere is tight. I even raised my sail and used my mainsheet (travelled way over to the edge) to lever the mast towards one side, then the other... no joy. The sailing was fine, and I felt much more secure with those new shrouds holding everything together. Still, other commenters on this forum have described setting their shroud pins near the bottom of the range to properly rake the mast. Why can't I do this with my new shrouds? No, I didn't measure the old ones... they look like original equipment, but who knows.

My other concern is related to the process of lowering the pins in the shroud adjusters, following the initial hookup. It also relates to the post-sail teardown, too, as the pins are symmetrically moved up to allow some looseness. With the old shrouds, I used a couple of Phillips-head screwdrivers through the adjuster holes, so that there was ALWAYS a secure shroud-to-boat connection; I'd "walk" the adjustment until it was near the pinning point, then insert the clevis pin and secure it. Because of the marine eye on my new cables, I can't do this! How do I safely adjust the shrouds?

Rick
Posted By: CMerrell

Re: Old Boat, New Shrouds - 04/19/07 12:20 PM

First problem:
Standard length shrouds are now shorter than they used to be due to the desire for more mast rake and the redesigned jibs. As a result, standard length forestays are now longer.

If you are happy with the mast rake you had with your old shrouds, you may be able to acheive it with the new shrouds. The important thing is the mast rake geometry and not which hole in the side chainplates you are using. Put the old shrouds on and raise your sails as usual. Using the main halyard to measure, mark it at a convenient reference point on the boat (lip on hull at the transom, for example). Put the new shrouds on and raise your sails again. Pin the shrouds in the chainplates such that the halyard mark meets your reference point. See if you can pin the forestay to the top hole in the bow chainplate(s). If you can, you are done. If you cannot, the slick solution is a longer forestay. The "redneck" solution is a daisy chain of additional shackles, chainplates, what-have-you.

If you want and can acheive more mast rake, it may be limited by how tightly you can sheet the jib (and the forestay length problem).

Second problem:
I don't understand why you are messing with the side chain plates (walking down the pins with a screwdriver, etc.) The side chain plates are typically "set it and forget it". Rig tensioning on a H16 is accomplished by the jib halyard. After raising the mast, pin the "standing" forestay to the top hole in the chainplate (many folks use a double chainplate). Attach the jib and then tension the rig. The internal forestay in the jib becomes the "working" forestay.

Please let us know your results.
Posted By: hititmaestro

Re: Old Boat, New Shrouds - 04/20/07 03:46 AM

Also you have to remember that our older boats have a 7 hole forestay adjuster where new boats have a 10 hole set up
Posted By: Karl_Brogger

Re: Old Boat, New Shrouds - 04/20/07 03:50 AM

Using 2 chainplates on the forestay works really well. When the jib is up and tight use a small bungee to pull the top chainplate forward away from the boat. It looks goofy but it keeps the loose forestay from rubbing against your jib. And in light air it won't effect the shape of the jib either.
Posted By: RickInMesa

Re: Old Boat, New Shrouds - 04/20/07 05:17 PM

Well, this makes perfect sense, and your insights and suggestions are exactly what I was looking for.

First of all, I am using a double chainplate at the bridle, and I pin the forestay in the top hole of that combo. What surprised me during my first setup with the new shrouds (pre-pinned in the top hole of the chainplates) was that the forestay just barely reached the pinning point. So my geometry with the new shrouds is very close to my geometry with my old shrouds... there's just not a lot of extra space and slop during the setup of the rigging.

I need to replace the forestay, and I'll expect it to be longer than the one I have, and perhaps I can get rid of the extra chainplate at the bow.

I know about how the jib is the "real" forestay on the boat, once tensioned. I usually pull enough that the "rigging forestay" has a few inches of looseness in it. I will be replacing my sails later this year (they're the original ones!) and when I do, I'll expect that the cut of the new jib will work better on the raked mast setup. The way it is now, the jib rides so high (ten inches higher than it should, it seems) that I can't get the right shape when I sheet in... it pulls the clew downwards too much, instead of aftwards.

Oh well... one thing at a time. Thank you for your advice!
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