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-   -   halyard shackle letting go, spinnaker halyard interference (http://www.sailnet.com/forums/gear-maintenance/74591-halyard-shackle-letting-go-spinnaker-halyard-interference.html)

ctlow 05-19-2011 05:05 AM

halyard shackle letting go, spinnaker halyard interference
 
Twice now, on a high mast ("P" over 38'), I've had the foresail halyard shackle let go, crashing the foresail down onto the deck and into the water, and losing the foresail halyard, the shackle damaged and stuck at the sheave at the top of the mast.

There are "factors" ...

1/ The spinnaker halyard lies against the forestay, way up there. I've re-routed it this year, taking the "standing" part outside the mast - it used to be inside - but I can't reposition the block, way up there, from the deck, it turns out. The block is centered on a U-shaped rail sticking out forward from the mast-head. I had hoped to be able to slide the block on its rail around to the side, but so far: no joy. (The U-shape has a dip, forward, so trying to pull it sideways does not overcome the downward force keeping it in the center of the dip.)

Last year, the furling mechanism clearly snapped against the standing part of the spinnaker halyard, eventually wearing through and parting that halyard. With the spinnaker halyard gone, and this year with it all "outside", the snapping is gone. (Clearly that was bad.)

2/ Some of my sails are too long in the luff (and some not), so the old Harken furling mechanism bangs right up at the top of the forestay with still a little looseness in the sail's luff. I'll deal with this eventually - sailmaker and so forth - but in the meantime I wonder if having virtually no halyard showing above the furling mechanism is bad for it as it furls. The halyard is supposed to be short, according to the Owner's Manual, and there is no wrap-stopper in this system.

3/ I came across a helpful thread here saying to loop both runs of the spinnaker halyard around behind a spreader. I'll try that and hope for enough length of halyard. (Then I have to remember that it's there and handle it appropriately before and after using it ...)

4/ I use a snap shackle at the halyard-furler join, and I think that's because that's the way the boat came. Last year I actually lost the pin, and when I finally retrieved it, I took the pin from a new shackle and put it in - seemed perfect - and that way didn't have to cut the old shackle out of a beautiful spliced loop. But I do wonder why it requires a snap shackle. I attach that halyard basically once a year, and don't need to change it even when changing sails occasionally.

The photo is from when the spinnaker halyard ran inside the mast. I think it illustrates the situation better than words.

http://www.boatdocking.com/ForesailH...ennant0306.jpg

I know that's a lot, but if anyone sees any room for improvement in there, please let me know. I have a second foresail halyard, which has rescued the situation, but nonetheless, I have to fix this and stop if from happening.

Thank you.

Charles

Minnewaska 05-19-2011 05:59 AM

Do you use multiple foresails? If not, I would replace the snap shackle for the foresail with a regular screwed down shackle. Even if you do, it would only be a problem if racing. It takes 15 seconds to unscrew. The downside is dropping the pieces.

Minnewaska 05-19-2011 06:01 AM

Alternatively, the spinnaker block could be moved an inch or two off center. It wouldn't make an difference in performance.

svHyLyte 05-19-2011 08:09 AM

That appears to be a home-made spinnaker crane as a standard crane normally has two rings that angle out at 45 degrees from the center-line on either side of the headstay. Two because one normally needs the ability to hoist a new spinnaker before dropping the old one (a "peel"). However, the simplest fix would be to have your sailmaker add a spectra cover to your spinnaker halyard for a couple of feet on either side of the wear location. Frankly, however, it looks like the hoist of the jib is too great and I wonder how the tack is attached to the furling drum at base of the headstay. Also, FYI, adjusting the hoist would solve another problem. That is, your jib halyard should make an angle of no less than 10 degrees from the alignment of the headstay to avoid halyard wraps. This is accomplished by adding a halyard guide just below the halyard block at the mast-head. With this arrangement, the swivel/spindle at the masthead would be lower, reducing, but not eliminationg, chafe, as the halyard will still chafe against the headstay when the spinnaker halyard exit slot is to windward given your crane arrangement. Frankly, I'd replace the masthead crane--Garhaurer will make a proper crane for you very inexpensively--adjust the jib hoist, add a jib halyard guide; and, add spectra covers to both spinnake halyards.

FWIW...

Minnewaska 05-19-2011 08:16 AM

I think I'm confused. Is the problem that the spinn halyard is chafing and breaking or are you catching the jib halyard snap shackle and it releases? I thought the later, but think I may have misunderstood.

ccriders 05-19-2011 08:20 AM

Can you turn over the spinnaker bail so that the dip is up? If you can then the halyard will always be on one side or the other.
John

Faster 05-19-2011 09:37 AM

I think that's a bad crane design... it should not be centered, as mentioned already, and it's too long and drops too far...

Modifying that would probably make all your issues go away.. and enable you to go back to an internal halyard run.

zz4gta 05-19-2011 09:50 AM

Here's a NASA fix for ya. Tape the jib halyard.

ctlow 05-20-2011 11:55 AM

Thank you all. Great ideas. The Harken furling manual - and it's so old that it comes as poorly type-written sheets, stapled together - does refer to an extra block if required to get the correct jib halyard sheeting angle. I'll review that. I have more to learn about "cranes" for spinnaker halyard blocks. I should just sacrifice the lovely jib halyard splice and remove the snap shackle - one friend and "expert" just ties a bowline, no thimble or splicing, and has always had that work (speaking of "NASA" solutions). I have to document which of my sails are too long and which too short (on the luff) and have them adjusted. (And I could try to understand why that's changed from last year ...)

I don't normally use multiple foresails for our "casual" club racing - and to do so would have to remove the upper part of the furling mechanism, which is not impossible, but a bit of a hassle.

(For clarity: my problem was both with the jib halyard shackle releasing and with wearing through the spinnaker halyard [and that on occasion interfered with furling the foresail].)

Thank you again. I may be back about this!

pdqaltair 05-20-2011 02:13 PM

I'm with Minnewaska:

Why not eliminate the spin shackles? D-shackles won't release.

There is really NO cause to use spin shackles on a furling sail that is probably lowered 1-2 times per year. I don't care for them anywhere but spinakars or jibs on race boats that frequently change head sails (multiple times per day). Otherwise, they make terrible halyard shackles. Never use them anywhere where a suprise disconect is painful. They make sense on a chute, where fast release is important to safety.

Yes, you may drop a few pins. Probably not, not once you learn how to hold them (with a little side force on the pin to hold it in place while threading the sail--haven't dropped one in years). But you'll salvage 2 expensive spin shackles in the trade.

--------------------------

It's probably not a surprise that rock climbers don't even own them and that you don't use them climbing the mast.


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