|Topic Review (Newest First)|
|05-23-2011 10:55 AM|
|puddinlegs||Spinnaker crane design. All other fixes are just working around that problem.|
|05-23-2011 07:45 AM|
|JimsCAL||Was the mast pulled last fall? Only explanation I can come up for the shorter forestay with is that the forestay turnbuckle is adjusted shorter this year than last. But a couple inches is a lot!|
|05-23-2011 06:16 AM|
Thank you pdqaltair and paulk.
All excellent observations and I'm still working on this.
I have removed the snap shackle between the jib halyard and the upper part of the furler. (Hated wasting that lovely splice, but it was either that or cut the shackle.)
The spinnaker halyard block will not move off to the side. The dip in the "crane" holds it extremely solidly in the middle. I've taken it, from deck level, all over the deck and it won't budge. I went up the mast and tried to move it by hand, and it won't budge. Removing all tension from the spinnaker halyard would work, but that can't be done from deck level, because simply pulling on it to try to move it applies sufficient tension to lock the block solidly in the middle of the dip in the crane.
When I say "solidly" I mean it won't slide sideways one iota. When the mast is down and there is no halyard on it, then it is completely free.
The "crane" is welded on to the mast-head fitting. I could consider having this re-machined over the Winter. Clearly "something" should be done. Perhaps I can clamp some small fitting on the crane which would hold the block off to one side.
In the meantime, I have also looped both "arms" of the spinnaker halyard around the back of a spreader, and that does seem to keep them off the forestay - the one arm just barely off, but not touching is not touching. I'll keep an eye on the halyard for wear as it wraps around shrouds, and of course will have to free it up when I use it.
Related dilemma: the forestay has shortened this year. So far, both my #2 and #3 foresails are too long on the luff, with a little sag left when the upper furling mechanism is fully hoisted (and it shouldn't be fully hoisted anyway). I may have had a little of this last year with one of the sails last year, although ...
... in order to shorten the exposed halyard and prevent halyard-wrap when furling, I added a 6" wire "pennant" to the luff, which worked like a charm. This year it's too long, and I have had to remove the pennant. Now, I did add one more shackle into the mix, at the tack, a snap shackle (I know!) for easier sail-changing. (I'm thinking of not furling my new headsail, but taking it up and down for every weekly race.) But that's nowhere near 6". Nothing has changed to my knowledge in how the boat is rigged, and this is my 4th Summer of ownership.
How could such a thing happen, that the forestay this year is a few inches shorter than last year, or conversely that last year was anomalous and it was longer that year than usual? Just weird. Apart from the backstay turnbuckles, there is nothing to adjust without disassembling the furling basket etc., and I haven't done that. It's a deck-stepped mast with no adjustments a the step itself.
Also, I have a D-shaped shackle at the tack, which fits the lower part of the furling mechanism, but it requires tools to unscrew and screw in the pin (to make it firm enough for my satisfaction), which is not impossible but seems laborious on occasions with few crew and a pitching deck. There was a quick-release type of shackle, of the general type pictured below, there at one point, but it also required tools - perhaps it was simply damaged and I need to replace it. Thoughts?
Thank you all again.
|05-20-2011 11:42 PM|
|paulk||From the photo, it looks like the snap shackle on the jib halyard is hitting the forestay. THAT may be your problem. Added to that, the too-long luff you mentioned on your jib means the whole thing isn't pulled tight, so it slops around more than it might otherwise, enabling the stay and the shackle bang against each other on every single wave you hit, or that hits you. That, plus the shock loading of the snap shackle, as the mast whips back and forth. Bang on anything long enough, and it will break. You might want to carefully inspect your forestay around where the shackle's been hitting it too. The spinnaker crane seems to have been designed for a totally external spinnaker halyard. If you simply led the two ends down to the sides of the mast, the block would swivel to be at right angles to the forestay, and the spinnaker halyard(s)might not even touch the forestay or r/f gear. Rigging the spinnaker halyard so that it chafes on the r/f or forestay, as the photo shows, is not a good idea: you mentioned that it has also chafed through. Running it inside the mast to reduce windage seems pointless with such a telephone pole-like spar. Good luck!|
|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.
|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!
|05-19-2011 09:50 AM|
|zz4gta||Here's a NASA fix for ya. Tape the jib halyard.|
|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.
|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.
|05-19-2011 08:16 AM|
|Minnewaska||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.|
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