Furl my genoa in which direction??

[YachtAllegro]

Hi

I'm just in the process of buying a Plastimo roller furler and new genoa to go on it. I see the Plastimo manual says "The genoa should be reefed in the same direction as the strands turn on the forestay". So I've looked at my forestay and pondered, and am confused! Since the strands form a spiral, they seem to me to turn one way going up and the other going down. Which direction is Plastimo talking about?! Anyone know?

Cheers
Patrick

 

[FWB]

Furl it so that the UV strip is on the outside when furled.

 

[YachtAllegro]

Furl it so that the UV strip is on the outside when furled.

Sure. But the sail's not made yet - which side do I want the UV strip? Plastimo imply there's a right and a wrong direction, but I can't work out which it is!

Cheers
Patrick

 

[Poignard]

Hi

I'm just in the process of buying a Plastimo roller furler and new genoa to go on it. I see the Plastimo manual says "The genoa should be reefed in the same direction as the strands turn on the forestay". So I've looked at my forestay and pondered, and am confused! Since the strands form a spiral, they seem to me to turn one way going up and the other going down. Which direction is Plastimo talking about?! Anyone know?

Cheers
Patrick

In the direction that tends to tighten the lay of the wire rope.

If you take a piece of 3-strand rope and twist in both direction you will see that twisting it one way tends to unlay the rope but turning it the other way tends to tighten it.

 

[Billjratt]

Makes sense (although it's the first time I've heard of it).
If you get a halliard twist-jam it will tend to tighten the lay rather than unravel the stay as I found out on my last boat...must check my current setup though there's not enough halliard to wrap on this one.

 

[maby]

In the direction that tends to tighten the lay of the wire rope.

If you take a piece of 3-strand rope and twist in both direction you will see that twisting it one way tends to unlay the rope but turning it the other way tends to tighten it.

Are you sure about that? The instruction as stated is pretty ambiguous : "The genoa should be reefed in the same direction as the strands turn on the forestay" but logic seems to suggest the opposite interpretation to yours.

First, I would interpret "reefed" as meaning the same as "furled" in other words the action of winding the sail in to stow it away. Letting the sail out is "unfurling". Now, as you suggest, the factor that determines the direction to roll the sail is the potential to unlay the strands - and reduce the forestay tension - if friction between the furling mechanism and the stay means that the stay tends to get dragged round with the furler. I would hoe that this would be a minimal effect since a multistranded wire rope is a fairly stiff thing that does not unlay easily and one would hope that the bearing surfaces on the furler would run reasonably freely.

But... If there is enough drag as you rotate the furler to put any twist on the forestay, which way do you want it to apply? I would have thought that you would have wanted it to tighten the forestay (albeit not by much) when the sail was deployed, not reduce the tension - hence you roll the sail in such a way that unfurling it will twist the forestay in the same direction as it is laid up - doesn't that make sense?

Of course, if you disagree with my interpretation of the word "reefed" in the original instruction, the whole thing is reversed!

 

[YachtAllegro]

In the direction that tends to tighten the lay of the wire rope.

Mmm. Thought of that. But that depends whether you're twisting the bottom or the top. Twist the bottom of my forestay clockwise as seen from above and the strands tighten. Twist the top of the forestay the same way and the strands loosen. If this is the correct interpretation, then is the twisting force going to be mainly applied at the top or the bottom??

Cheers
Patrick

 

[catalac08]

What may be more important is the direction of force needed to unscrew a swageless fitting if the foil binds on the forestay. When I fitted new rigging I spent some time deliberating on this and eventually fitted the swageless fitting at the bottom (right hand thread in the fitting) and the swaged fitting at the top and with the UV strip to port so the furling is done clockwise and so tending to tighten the fitting rather than loosen it.

Had a friend who lost his mast due to a binding foil on his forestay!

 

[YachtAllegro]

What may be more important is the direction of force needed to unscrew a swageless fitting if the foil binds on the forestay. When I fitted new rigging I spent some time deliberating on this and eventually fitted the swageless fitting at the bottom (right hand thread in the fitting) and the swaged fitting at the top and with the UV strip to port so the furling is done clockwise and so tending to tighten the fitting rather than loosen it.

That's an interesting thought. But there's still the question of whether you should be trying to tighten as you furl (on the basis that this is how the rig spends most of its time) or a you unfurl (on the basis that this is when the rig suffers the greatest loads).

I suspect there are too many variables here for there to be a definitely right answer, but I'm still slightly perturbed that Plastimo imply there is, but I can't understand it!

Cheers
Patrick

 

[Billjratt]

If it's to alleviate destruction in a halliard wrap jam situation as I mentioned earlier, the rotation of the foil at the top of the stay, and in a winding-in direction, is what we're interested in.
So if the wires look like a normal righthand screwthread when viewed from above, the foil should furl in a clockwise (viewed from above) diection.
If it seems a bit stiff and you resort to using a winch on the reefing line, you can break the forestay by unravelling it from the swage or whatever at the masthead. Then the whole rig will be supported by what remains of the offending halliard...
You - and everyone else in the immediate viscinity, will hear the creaking sound just before the sharp crack of the snapping rigging wire.

 

[DJE]

UV strips are on the Starboard side of my genoas. When I got a halyard wrap it untwisted the top of forestay. This suggests that maybe they should be on the port side. But since I fitted a halyard deflector I don't get halyard wraps any more (touchwood).

 

[Poignard]

Are you sure about that? The instruction as stated is pretty ambiguous : "The genoa should be reefed in the same direction as the strands turn on the forestay" but logic seems to suggest the opposite interpretation to yours.

First, I would interpret "reefed" as meaning the same as "furled" in other words the action of winding the sail in to stow it away. Letting the sail out is "unfurling". Now, as you suggest, the factor that determines the direction to roll the sail is the potential to unlay the strands - and reduce the forestay tension - if friction between the furling mechanism and the stay means that the stay tends to get dragged round with the furler. I would hoe that this would be a minimal effect since a multistranded wire rope is a fairly stiff thing that does not unlay easily and one would hope that the bearing surfaces on the furler would run reasonably freely.

But... If there is enough drag as you rotate the furler to put any twist on the forestay, which way do you want it to apply? I would have thought that you would have wanted it to tighten the forestay (albeit not by much) when the sail was deployed, not reduce the tension - hence you roll the sail in such a way that unfurling it will twist the forestay in the same direction as it is laid up - doesn't that make sense?

Of course, if you disagree with my interpretation of the word "reefed" in the original instruction, the whole thing is reversed!

What I meant was that as you pull on the furling line the tendency is to tighten the forestay. I have an old Rotostay and , viewed from above, the drum rotates clockwise as you pull the furling line. This tends to tighten the forestay, because it is a right-hand laid wire rope. That's how I have had mine set up for 15 years (and so did the previous owner) and it never gives any trouble.

 

[Salty John]

Interesting discussion. Profurl, Harken and Furlex all say to wrap the line in the direction to suit the location of the UV shield on the sail, they make no reference to the wire lay.

On a different issue, Profurl makes the recommendation that you lead the furling line away from the drum on the side of the anchor locker hinges. This is so that the furling line will never be trapped by the anchor locker lid. Clever.

 

[Poignard]

The only system I have any experience of is the Rotostay, and the whole forestay turns with the drum and foil (there is a swivel at the top of the forestay to allow this).

But looking at the Furlex website, it seems that the forestay there does not rotate so presumably it doesn't matter which way the drum/foil assembly rotates. I

Similarly for the Plastimo furler.

http://www.plastimo.com/pdf/T-Series(english).pdf

However the Plastimo instructions seem to contain a contradiction:

'The genoa should be reefed in the same direction as the strands turn on the forestay'

and

'The reefing line feeder on the 406T models is assembled on the right or left hand side of the drum unit, depending on which direction you prefer to reef'

 

[Simondjuk]

All wire is laid the same way and it seems to me that as many genoas furl one way as the other. Half of boats don't seem to be suffering from their forestay wires unlaying or swageless fittings undoing themselves. Therefore it would seem reasonable to conclude that it's not a big issue.

 

[CreakyDecks]

I can't believe it has anything to do with halyard wrap as that is something to be avoided altogether not catered for somehow. I think what they mean is that when you are furling the sail it should rotate in a way that will tend to "screw" the foil up the forestay, because that will tend to take the weight off it a little and make the operation easier. When unfurling it doesn't matter that it screws downwards because the wind is a lot stronger than we are!
Just my opinion and based on no knowledge whatsoever!

 

[MM5AHO]

I use a Harken
It only goes one way well, as the entry point to the drum for the furling rope is on one side.
I guess I could rotate that drum to put the entry hole on the port side, but it fits nicely to stbd, so the furling rope leads down the stbd rail. This rotates the furler clockwise as seen from above, and leaves the UV strip to the outside of the wrap of sail.