Is this Normal? - Shroud / Spreader Help

[pressuredrop]

so i got this little islander 24 on a trailer and all the bits and peices for free (im an a-hole, i know), this is a quick, cheap and easy project (if there is such thing), im halfway there and thinking about getting the stick up again.

here are some pictures of the lower shroud, spreader point. you will notice that the two lower shrouds on each side are attached to the same pin, and that pin is in the opposite side, on each side of the mast (that is the lower shrouds on one side area 4"-5" difference fore-aft from the other side.)

i thought this was madness until i noticed the other day that the chain plates on one side are a few inches further forward then the other so obviously it is suposed to be like this... now my only question is why???


also i think i need to make spreaders. the cylinder on each side of the mast where the spreaders go is 1" diameter. i was thinking that i could use aluminum tube with an ID of 1" and hold it in with set screws... good idea? bad idea? better ideas?

here is a like to some pictures of an I24 sailing... so you get an idea of the spreaders, and guessed on how big they should be?

thank you oh great ones of the cruisersforum,

Ben

[barnakiel]

I might not be correct, but I believe:

- the tangs (or whatever we call the plates holding the shrouds at the mast side) are turned 90degs on your pics - so they are not "...further aft / or further fore..." - turn them back in line with the mast as this is probably the way they are designed,

- I bet you can use alloy tube for spreaders (do not use SS tube though), now design a nice spreader-tip so that shrouds will not cut your spreaders in half, or do you have the original spreaders and can re use the tips?

b.

[pressuredrop]

thanks b, interesting thought that they are turned 90 degrees, cant believe i didn't of that... however what leads me to believe that this may be the correct orientation is that the chain plates are farther foward on one side, as witnessed by the bolts on the inside, in relation to the bulkhead that is under the mast. (ex: on one side there are two chain plates forward of bulk head, with one being just fore of it, and on the other side there is only one chain plate foward of the bulkhead, and the second is just aft...) catch my drift?

[FSMike]

There is no reason I've ever heard of for your chain plates to be located in different spots relative to distance back from the bow. By any chance is your bulkhead staggered so it meets the hull two different distances from the bow? If not, I think I'd relocate the chain plates as necessary to get them symmetrical .

[pressuredrop]

mike - thats a possibility, i will give it a good look tommorrow... its very possible since they are partial bulkheads and not one piece, okay, this makes a lot of sense now... those things get rotated 90 degrees and bolted into the mast with those holes...

this boat hasnt been in the water in 20 years and the guy who i got it from did some nice things (custom gas and water tanks that are still brand new) he did a few other things funny which i have since corrected (like putting the tiller on upside down and backwards... go figure, thanks guys i think im heading in the right dirrection on this...

[barnakiel]

I am sorry guys but I lost YOUR drift. The tang has to work verically from the attachment point, right? Otherwise, you create a load that will try to bend and twist the tangs.

The chainplates must be symmetrical to the mast fore and aft. It might be the bulkhead is NOT aligned correctly with the hull, but it would be very unusual and I believe should be corrected.

b.

[FSMike]

barnakiel -
What we were discussing is the possibility that the boat has two partial bulkheads rather than one complete bulkhead. That could mean that each bulkhead could be attached to the hull in different locations. Stranger things have been done. As far as the tangs go, you're correct that they just need to be turned so as to point at the appropriate chainplate.

[roverhi]

It's also possible that they just misaligned the bulkhead when the boat was built. It may just have been fitted at a slight angle which would account for the discrepancey. Islanders weren't the best built boats in the world and not much profit in a small one to make them want to correct inconsequential errrors.

I'd be willing to bet that the two sides of the main bulkhead weren't designed to be directly opposite each other. Not an uncommon thing to do when the interior plan is not symetrical and you need the extra room for a berth.

On our Westsail, the factory mounted the bulkhead 8" further forward than it should have been. A bit of an embarassment when the mast post to support the Mast was aligned with the bulkhead, not where the mast was supposed to go. Didn't discover it till I was getting ready to step the mast after the boat was nearly finished. Fortunately, there was enough shroud position leeway that we just moved the mast step over the bulkhead. Actually ended up with a better sailing boat for the error.

Pull a tape and measure from the bow. That will tell you whether the chainplates are correctly located. I wouldn't worry about if they aren't in exactly the right place. If the boat has been around as long as that one has without losing the stick, it last a lot longer.

[Stillraining]

Interesting...never heard of such a thing.

[delmarrey]

One item that I see that would be a concern is that you have only one bolt holding two shrouds on each side. I think I would check for wear on the bolt and the brackets.

As well, what is that appendage mounted to the bolt. It that where the spreaders slip over. If so, no set screw is needed. The upper shroud will hold them in place.

The chain plates being an inch or two off shouldn't affect the rig but more may cause a slight twist in the mast.

BTW- Be sure not to kink the wires, especially right at the swag fitting.

[Ex-Calif]

There is nothing to say that this is any of the original equipment.

1 - Measure from the bow to all the chain plates on each side. Internal bulkhead locations are meaningless.

2 - Everything is required to be symetrical

3 - Assuming this boat originally had 3 chain plates it looks consistent with what you have. 2 lowers and an upper. I would guess that the upper attaches to the middle chain plate and there is a lower forward and lower aft - OK I got some images and this appears to be the case.

4 - What has me for a loop is the lowers attach fitting. The fitting could orient horizontal and one lower mount forward and one aft but that makes little sense. That would introduce significant twist and load on that fitting. I am with Barnakiel that the fitting should align vertically but for the lif of me can't figure out what the 3-holed tang would be for.

5 - Also agree with Del. Find aluminum tube with an ID to match the "post" and no set screw is required. As for length there is a pretty good photo in the link below showing the spreader length such that the lower section of the upper shoroud is vertical to the chainplate. You will need to manufature a plug for the outer end where the shroud will ride and change direction.

Here's a couple of links that may be helpful.

Islander Sailboat 1961 I24 Hull #26

ISLANDER BAHAMA 24 Sailboat details on sailboatdata.com

[barnakiel]

Originally Posted by Ex-Calif

...can't figure out what the 3-holed tang would be for.

It could, well, "be for nothing" ...

Maybe it is a fitting designed for another mast (where the 3 holes could be used for screws, bolts or, fear to think-of-but-yes: rivets).

If the rig is fractional, then these holes might have been envisioned for some sort of rigging that would give stiffness to the top section of the mast.

But I bet they just ARE, without any particular reason to be.

b.

[SkiprJohn]

Three holes could be for a jumper stay?

regards,