Fairleads

[CaptainStan]

In The Sail Trim Users Guide Don talks about moving the fairleads in or out. The fairleads on my boat are cliped on to the toe rail. On a lot of boats they are on a track for moving forward and back. How can you move the fairleads in?
When I am close-hauled the jib sail is almost touching the spreader as it is.

 

[Joe]

Look up "Barber-hauler" if you're seeking a method to bring your lead inboard. (or outboard even) Moving the lead in or out changes the sheeting angle... that's the angle between a line drawn from tack to lead block and the boat's centerline. Moving the lead forward or aft changes tensions on the headsail's leech and foot inversely. If both edges are equally tensioned the sail is in a neutral position. Your lead blocks, though not on a track for easy movement, can still be adjusted fore and aft. If you equip the blocks with snap shackles they are even easier to move to another hole in the toe rail. (assuming you have a traditional toe rail, an actual rail that is perforated)
Moving the lead forward, increases leech tension and decreases the foot's, making the sail rounder (more full) and thus powered up. Moving the block back will ease leech tension and increase that of the foot. This depowers the sail, it becomes flatter as the leech opens and lets air spill off the top.

Regarding moving the lead in or out... there is an optimal sheeting angle for every design of boat and sail for varying conditions. Rigging a barber hauler is a good method to test your boat's proclivity to changing the sheeting angle. A large genoa headsail may not respond to the smaller angle, but a small 100% jib may. You might see better upwind performance. But............. then again........ you may not........ so you do the research.... make some notes... then get back to us with your findings.

 

[RoyS]

Also it is worth the slight effort and very minor expense to place tell tales on your sails. These will show you when you have your sails trimmed for optimum performance.

 

[Stu Jackson]

To add to Joe's and Roy's answers: moving the leads in & out are used for both going upwind to get the best sheeting angle as well as points of sail. Many boats have both inner & outer fairlead tracks, i.e. one inboard on the side deck primarily used for going upwind, and another one on the edge of the gunwhale for use off the wind and down wind.

It's as simple as that.

 

[Don Guillette]

To add to Joe's and Roy's answers: moving the leads in & out are used for both going upwind to get the best sheeting angle as well as points of sail. Many boats have both inner & outer fairlead tracks, i.e. one inboard on the side deck primarily used for going upwind, and another one on the edge of the gunwhale for use off the wind and down wind.

It's as simple as that.

The section of the book Stan is referring to deals with the 6 primary jib adjustment - one of which is the placement of fairleads inboard or outboard. Fairleads have to be attached to something and that something, on boats above 30', is normally as, Stu points out, a track but it could be anything. If the boat has only a outboard attachment point or track a way is needed to get the sheet angle inward for closehauled work and Joe from San Diego described exactly what that is - a Barberhauler. Boat builders, in an effort to save cost, generally only provided one track and it's outside, which is great for all points of sail other than closehauled.

For those that have my book, they know the origin of the term "barberhauler". It has nothing to do with anything nautical. The Barber's are 2 brothers who raced Lightning's against Dennis Conner in San Diego. They stumbled on the concept of inboard and beat the pants off their competitors in the process until everyone else caught on. Both became dentists and Dennis Conner is one of their patients.

 

[Joe]

Also it is worth the slight effort and very minor expense to place tell tales on your sails. These will show you when you have your sails trimmed for optimum performance.

I can't imagine anyone not having telltales on their headsails. I've never even heard of a manufacturer not installing a basic set on every sail they make. Most important trim tool you can have.... even if your sail trim options are limited (such as non moveable fairleads), you use the bottom tells to steer efficiently.

 

[Don Guillette]

I can't imagine anyone not having telltales on their headsails. I've never even heard of a manufacturer not installing a basic set on every sail they make. Most important trim tool you can have.... even if your sail trim options are limited (such as non moveable fairleads), you use the bottom tells to steer efficiently.

Joe: I can't imagine anyone above the grade of "set it and forget it sail trim" not having them either. When I lived in So Ca and folks would contact me to help them with their sail trim problems I always took a set with me. Also, as I stepped on the boat the first thing I looked at was their fairleads (most were frozen in place) and then the outhaul (that control mostly didn't work either) - that took about 15 seconds!!
I knew they didn't have telltales because if they had telltales would have told them that their sail trim was off. I didn't blame them because a "person doesn't know what he doesn't know" and we weren't born with sail trim knowledge - we all had to learn it.

On the other hand, some boats had all the controls working BUT no telltales. I asked them how would they know when they were at 100% with out them? I can't and and I know what I'm looking for.

 

[CaptainStan]

Thanks everybody. I got a new genoa last year it has tell tails and lines across it so that you can better see the sail shape as you look up the sail.
I would have to partially roll up the genoa to bring it inside the shrouds.
I don't know if the increased slot effects will make up for the reduced sail?

 

[jssailem]

I don't know if the increased slot effects will make up for the reduced sail?

The old thinking about "slot Effect" has been replaced with scientific study of sail air flow dynamics.
A study of the works by Arvel Gentry a Boeing Engineer who applied aerodynamics to the art of sailing in the mid 70's.

https://www.northsails.com/sailing/en/art-science-sails/gentry

Gentry Sailing | Recalling the research, writing and design of Arvel Gentry

You may discover that the proper sail shape has more to do with moving your boat than the size or shape of a slot.

 

[CaptainStan]

The old thinking about "slot Effect" has been replaced with scientific study of sail air flow dynamics.
A study of the works by Arvel Gentry a Boeing Engineer who applied aerodynamics to the art of sailing in the mid 70's.

https://www.northsails.com/sailing/en/art-science-sails/gentry

Gentry Sailing | Recalling the research, writing and design of Arvel Gentry

You may discover that the proper sail shape has more to do with moving your boat than the size or shape of a slot.

Thanks Jssilem. I have heard of of Avrel Gentry. Has he written anything about how to trim sails?

 

[jssailem]

Follow the link and you will be able to read his writings and understand what it is about sails that makes the boat move. Armed with that knowledge you can begin to understand what it means to trim a sail. He explains the technical in terms that are understandable. Knowing what is causing the boat to go fast can help you in shaping the sail (trimming) and adjusting the angle of attack to optimize performance.

If you are just interested in "the how" and not "the what" powers up your boat, look at the works of Frank Bethwaite.
High Performance Sailing is a great book on the technique of trimming a boat to go fast.

 

[jon hansen]

love frank bethwaite's book

 

[Don Guillette]

Follow the link and you will be able to read his writings and understand what it is about sails that makes the boat move. Armed with that knowledge you can begin to understand what it means to trim a sail. He explains the technical in terms that are understandable. Knowing what is causing the boat to go fast can help you in shaping the sail (trimming) and adjusting the angle of attack to optimize performance.

If you are just interested in "the how" and not "the what" powers up your boat, look at the works of Frank Bethwaite.
High Performance Sailing is a great book on the technique of trimming a boat to go fast.

Said another way - a person(skipper) can be told WHAT to do BUT the WHY is everything. Most beginner to intermediate sailors I've run into have the boat and are trying to figure out how to sail it. They raise the main and roll out the jib and the boat moves through the water. Some are happy with that but others want to get more out of their sails. It's like buying a plane with no flying experience and trying to figure out by yourself how to fly it. They should have gone to ground school first to understand what makes the plane/boat fly. Actually, if you turned a boat on it side and got it to go through the water it would be called a plane!!

My approach for the struggling sailor is that they have the boat and now have to take 2 steps backwards. One step is to understand WHAT all the sail trim controls for the main (there are 8) and the jib (there are 6) are are adjusting - there are ONLY 4 elements and unless the sailor has a complete understanding of those 4 elements sail trim will never make any sense. The sailor can read every sail trim book written about increasing sail trim performance and the sailor won't know what the author is talking about.

Once the sailor understand WHAT the sails are adjusting, the next step is to figure out WHICH sail trim control for the main and jib adjust WHICH of the 4 elements. For example, which mainsail trim controls adjust DRAFT POSITION? Which of the 4 elements does the fairleads adjust ? - ALL 4!! At this point he's 75% home. Now he has to figure out the correct adjustment for each point of sail and wind condition.

 

[Stu Jackson]

The sailor can read every sail trim book written about increasing sail trim performance and the sailor won't know what the author is talking about.

I might have mentioned this before, but here goes again.
I've read ALL the sail trim guides and Gentry and other online sources.
NONE of them does what Don's excellent Sail Trim book does.
None of them.
It is, by far, the BEST reference for the why, what and how to trim sails I have ever read, and I've been reading about this subject for 60 years.
I rarely use the word "best" when it comes to sailing, because we all (should) know that all boats are compromises when it comes just about everything. There have been many respondents on various boating forums who have correctly responded to those ubiquitous "What's the Best...?" questions. We've all seen them.
But when it comes to SAIL TRIM, Don's is THE BEST.
As a handy dandy extra bonus, there is a great section on racing that I have never seen anywhere else, ever, never. It alone is worth the price of admission. Think about it: How come there aren't a whole lot of "Teach me how to race?" questions on this or other boating forums? You know, like the recurring "I want to buy my first sailboat and go around the world but I've never been on a boat?" ones. I maintain that part of it is that a successful racer doesn't want to give away his techniques to the competition. I sure don't. But part of it is also "feel", something that one can't impart to anyone else. That said, Don's explanations and ideas in his succinct few pages on this subject alone are priceless and well worth the read.

For those of you who would like to get the most out of your SAILboats, please buy Don's book. It will help you to do so.

 

[CaptainStan]

I bought Don's book and read it twice then lent it to my friend that I sail with all the time so that he would understand what I am trying to do trimming my sails and he lost the book.
My new genoa has two lines across it as well as tell tales but I don't know how the lines help with sail trim other than letting you see shape of the sail better.

 

[Davidasailor26]

I bought Don's book and read it twice then lent it to my friend that I sail with all the time so that he would understand what I am trying to do trimming my sails and he lost the book.
My new genoa has two lines across it as well as tell tales but I don't know how the lines help with sail trim other than letting you see shape of the sail better.

I presume you mean black stripes on the sail running horizontally from luff to leach? If so those are “draft stripes”, and their function really is just to be able to see the shape of the sail. They give a good contrast to visualize the amount of draft and twist to the otherwise featureless cloth.