Is there a problem with halyard wrap if sail luff is 1" under max luff on MKIV Unit 2 Furler? Max Luff is 44' 1" and the sail is 44'.
Sail is close to furler Max Luff
- Thread starter Mitchin
- Start date
I think I understand what you are asking:
You have a furler that specifies its maximum luff length as 44' 1". Your sail has a luff length of 44'. You are wondering if this narrow gap could contribute to the likelihood of halyard wrap. Do I have it right?
The answer is maybe/probably, but with a few unknown factors to qualify that response. The issue is much less about how close you are to the furler's max length, and more about the angle between your forestay and the halyard. I have read recommendations of anywhere from 10 - 20 degrees, that you want, but I have never found anything that clearly describes how that measurement is taken or any evidence that there is a magic angle. Suffice to say, you want some angle there.
If you already have a halyard restrainer, then you probably don't need to worry about it. My guess is that you do not, or you wouldn't have asked the question.
The other question is whether the furler has a halyard deflector (a little disk designed for this purpose). Again, you probably wouldn't have asked the question if it did. I will say that, if I were concerned about halyard wrap, in this instance, I would just add a halyard deflector.
You have a furler that specifies its maximum luff length as 44' 1". Your sail has a luff length of 44'. You are wondering if this narrow gap could contribute to the likelihood of halyard wrap. Do I have it right?
The answer is maybe/probably, but with a few unknown factors to qualify that response. The issue is much less about how close you are to the furler's max length, and more about the angle between your forestay and the halyard. I have read recommendations of anywhere from 10 - 20 degrees, that you want, but I have never found anything that clearly describes how that measurement is taken or any evidence that there is a magic angle. Suffice to say, you want some angle there.
If you already have a halyard restrainer, then you probably don't need to worry about it. My guess is that you do not, or you wouldn't have asked the question.
The other question is whether the furler has a halyard deflector (a little disk designed for this purpose). Again, you probably wouldn't have asked the question if it did. I will say that, if I were concerned about halyard wrap, in this instance, I would just add a halyard deflector.
The closer the sail is to the furler's maximum hoist, the closer the top swivel is to the halyard exit, and the less chance of a halyard wrap - both because the angle of the halyard increases, and its length gets shorter.
Halyard wrap potential is a different topic than sail luff length, other than the above. Regardless of luff length, the furler should be setup to prevent a wrap as described in its installation manual.
Your only concern with your long luff length is that it doesn't stretch anymore than another 1" when you have it tensioned properly. If that's OK, you are good to go.
Mark
Halyard wrap potential is a different topic than sail luff length, other than the above. Regardless of luff length, the furler should be setup to prevent a wrap as described in its installation manual.
Your only concern with your long luff length is that it doesn't stretch anymore than another 1" when you have it tensioned properly. If that's OK, you are good to go.
Mark
More furling issues.
Pic on left is recent 148 which hoists higher but wraps horribly unless - as has been done in pic - has the halyard tensioned bar tight. Not so good for luff especially if accidentally left that way after sailing.
Pic on right is old 130ish, hoists lower but only about a quarter wrap with normal halyard tension.
Sailmaker wants to cut 4" off the luff of good sail to emulate the wrap of the old sail.
I'm not so sure I want to lose any sail area in what is essentially is an experiment.
Originally he was simply going to install a tether to bring the carrier closer to the puck.
Or I could shorten the foil (big job) or lower the puck somehows, OR, move the restrainer down.
IYO, how far down you figure I should move the restrainer?
I'm thinking, say, 3" will do it.
...
Pic on left is recent 148 which hoists higher but wraps horribly unless - as has been done in pic - has the halyard tensioned bar tight. Not so good for luff especially if accidentally left that way after sailing.
Pic on right is old 130ish, hoists lower but only about a quarter wrap with normal halyard tension.
Sailmaker wants to cut 4" off the luff of good sail to emulate the wrap of the old sail.
I'm not so sure I want to lose any sail area in what is essentially is an experiment.
Originally he was simply going to install a tether to bring the carrier closer to the puck.
Or I could shorten the foil (big job) or lower the puck somehows, OR, move the restrainer down.
IYO, how far down you figure I should move the restrainer?
I'm thinking, say, 3" will do it.
...
Could be the angle, but I don't see a restrainer.
Move the restrainer down a few inches. Shortening the headsail will lower the swivel which will make the load path on the swivel inline with the forestay. That's a recipe for halyard wrap. The halyard needs to apply vertical tension on the luff and some horizontal tension on the swivel, enough so the upper part of the swivel is held in position.
Move the restrainer down a few inches. Shortening the headsail will lower the swivel which will make the load path on the swivel inline with the forestay. That's a recipe for halyard wrap. The halyard needs to apply vertical tension on the luff and some horizontal tension on the swivel, enough so the upper part of the swivel is held in position.
Restrainer's tucked up there right under the sheave box. So high it's actually not doing much of anything at all.
And yeah I am in alignment with your thinking on halyard angle.
And yeah I am in alignment with your thinking on halyard angle.
I can't believe a sailmaker proposed cutting a sail for this purpose. Are you sure they know what they are doing? The only reason a luff should be recut is if you want a different shape, or that is the cheapest repair of damage, or need to shorten to fit a different boat.
First, as noted, shortening the luff will make the matter worse, not better. Or at least the potential for being worse.
The way to fix this is to lower that halyard restrainer. It is the entire purpose of that being include with the furler package. It is part of the furler, but it looks like yours was installed incorrectly. Fix that and you are done.
The other way to fine-tune something like this is to put a lanyard on either the tack or hoist of the sail so that the upper swivel is higher up on the foil. Put it on the tack if you want/need more clearance on the deck, or put it on the hoist if you want the foot of the sail to stay where it is now.
What is that clamp thing on the forestay swage? I have a suspicion that was once part of the furler, or the furler was hoisted higher, and the halyard retainer was in the correct position then.
Mark
First, as noted, shortening the luff will make the matter worse, not better. Or at least the potential for being worse.
The way to fix this is to lower that halyard restrainer. It is the entire purpose of that being include with the furler package. It is part of the furler, but it looks like yours was installed incorrectly. Fix that and you are done.
The other way to fine-tune something like this is to put a lanyard on either the tack or hoist of the sail so that the upper swivel is higher up on the foil. Put it on the tack if you want/need more clearance on the deck, or put it on the hoist if you want the foot of the sail to stay where it is now.
What is that clamp thing on the forestay swage? I have a suspicion that was once part of the furler, or the furler was hoisted higher, and the halyard retainer was in the correct position then.
Mark
jssailem
SBO Weather and Forecasting Forum Jim & John
- Oct 22, 2014
- 23,141
The OP posted about the Harken MKIV Unit 2. The top swivel looks like this.
The length of the Unit 2 swivel is much shorter than seen in the @Drinky Crow images. How the sail and halyard attach to the Harken swivel is designed to reduce the possibility of halyard wrap.
Yes, you need to haul the sail up completely, but it should stop just before the end of the furler extrusion.
The question of "1 inch" can only be answered if you measure the forestay length and compare it to the sail length and furler parts, or when you actually raise the sail on the furler and see if it works.
If the sail length positions the swivel beyond the extrusion stop, it will fail to work.
The length of the Unit 2 swivel is much shorter than seen in the @Drinky Crow images. How the sail and halyard attach to the Harken swivel is designed to reduce the possibility of halyard wrap.
Yes, you need to haul the sail up completely, but it should stop just before the end of the furler extrusion.
The question of "1 inch" can only be answered if you measure the forestay length and compare it to the sail length and furler parts, or when you actually raise the sail on the furler and see if it works.
If the sail length positions the swivel beyond the extrusion stop, it will fail to work.
So issue was fixed with the addition of a 4" tether at head of sail.
After furling halyard is wrapped maybe a quarter turn and this with minimal tension on halyard.
I'm fine with this. I don't have to go up the mast or pay someone to. Or raise the sail as I don't want to raise the centre of effort. That's why I replaced the long-in-tooth Harken furler with a Facnor Flat Deck unit.
The restrainer is probably in the right place for a sail with a higher hoist. Like the 155 I should probably buy if I really want to stick it to my competition here in what is an essentially a light air venue.
Yes it is puzzling that the guy here at North whom I've been dealing with for almost 30yrs would suggest whacking 4" off the luff. He ain't stupid and does all the repairs and troubleshooting for some very serious local sailing programs.
So IIRC correctly there's a double ended "T" attached to the masthead requiring a toggle with clevis to mate to the swage at top of forestay.
If the rigger who replaced the wire and installed the new furler gave two shits* about what he was doing I believe he could have figured out a way to clean that up by attaching upper swage directly to mast head.
Maybe not. I'm not a rigger. But it's ugly especially that the tape's becoming tattered.
*you think the sailmakers suggestion was nuts, you shoulda' seen the work the work the "rigger" did and the way he went about it. Complete clown show.
After furling halyard is wrapped maybe a quarter turn and this with minimal tension on halyard.
I'm fine with this. I don't have to go up the mast or pay someone to. Or raise the sail as I don't want to raise the centre of effort. That's why I replaced the long-in-tooth Harken furler with a Facnor Flat Deck unit.
The restrainer is probably in the right place for a sail with a higher hoist. Like the 155 I should probably buy if I really want to stick it to my competition here in what is an essentially a light air venue.
Yes it is puzzling that the guy here at North whom I've been dealing with for almost 30yrs would suggest whacking 4" off the luff. He ain't stupid and does all the repairs and troubleshooting for some very serious local sailing programs.
So IIRC correctly there's a double ended "T" attached to the masthead requiring a toggle with clevis to mate to the swage at top of forestay.
If the rigger who replaced the wire and installed the new furler gave two shits* about what he was doing I believe he could have figured out a way to clean that up by attaching upper swage directly to mast head.
Maybe not. I'm not a rigger. But it's ugly especially that the tape's becoming tattered.
*you think the sailmakers suggestion was nuts, you shoulda' seen the work the work the "rigger" did and the way he went about it. Complete clown show.
There really should be no amount of wrapping at all. The picture looks like even hoisted fully to the end of the extrusion, the halyard could still easily wrap the forestay. Although it stops wrapping early now, it only takes a bit of dragging bearings, halyard stretch, or sail stretch to allow the halyard to catch, wrap, and take down the forestay.
Should have led with that. The restrainer was probably mounted correctly for the old furler.
I don't understand what's going on here at all.
Mark
Is of sail prior to the tether being installed.
As I said there was no real tension on halyard. Deliberately so to produce wrap which it didn't. Put another way the halyard would probably deflect as much even with a lower restrainer at that tension.
Not double ended, my bad, but like below.....so the end of that rod would have some kind of fitting, ball or other that's captured in the masthead, forestay swage on clevis pin at left end of image. Now ugly because of fraying riggers tape.
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OK, so the component in the picture is swaged onto your forestay, and the toggle is connected to some type of pigtail connected to the masthead fitting?
Seems strange, and likely that there was a more direct way to do that, as it is unlikely C&C designed it that way. But I don't see any practical issue other than a potential extra point of failure and the general cumbersomeness of it.
Sounds like the wrap issue is fine.
Mark
So better image. Spar was made by Cinkel (RIP).
Danny at Klacko opined it was not original to the boat.
But peeps at the FB page say some of the later boats came with these veritable tree trunk masts. I got about ~20" of rake because the Loos gauge went off the chart trying to put in the recommended 4" of pre-bend.
I got quoted 12K Cdn delivered to west coast to fix that. Lol.....
Danny at Klacko opined it was not original to the boat.
But peeps at the FB page say some of the later boats came with these veritable tree trunk masts. I got about ~20" of rake because the Loos gauge went off the chart trying to put in the recommended 4" of pre-bend.
I got quoted 12K Cdn delivered to west coast to fix that. Lol.....
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