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Discussion Starter #1
I have often read that in heavy weather having at least a small headsail (storm jib) up will help you point higher.

I have recently done some heavy weather sailing and have made nearly 4 knots with my reefed main alone on a beam reach. I understand that having some more canvas up in the form of the storm jib would give me more speed. But why would it allow you to point higher? I keep imagining that any canvas in front of the mast would tend to push the bow off the wind (lee helm).

In an unrelated question:
I have a great 104% headsail from a US25 that fits nicely on my Kent Ranger 24. I have un-tensioned the leech line but the leech still cups. Any tips? Should I move the jib sheet car farther away from the center of the boat - more lateral? More aft?

The track for my jib sheets doesn't extent very far forward, so when I use that 104 I put two snatch blocks on these padeyes that are farther forward, but closer to midline - inside the shrouds. Can I put the snatch blocks on the toe rail? Its got lots of holes in it and it seems pretty stout.

Thanks!
 

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The main is typically aft of the center of the keel. In that respect it just like hanging canvas off the stern
And with a sail hanging off the stern, you can't pull it in very tight or your boat will turn into a giant Windex or windvane, or at the very least your rudder will be swung hard over to counteract the unbalanced force as best it can.

To me, the headsaol lets you pull the main sheet in tighter, which lets it drive the boat with an apparent wind that's farther forward. And that's pretty much the definition of pointing higher.

Regards,
Brad
 

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Adding the headsail gifts you more lift, which pulls the boat higher. It also directs and aligns the airflow over the main, which also gives you more lift.

This article is a pretty good summary of sail trim:
Sail Trim 101

If you are leech is cupping it sounds like the jib cars are too far forward. If the sail is getting blown out then you won't be able to get the draft far enough forward and the draft will be too deep.
 

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Discussion Starter #4
If you are leech is cupping it sounds like the jib cars are too far forward. If the sail is getting blown out then you won't be able to get the draft far enough forward and the draft will be too deep.
Thanks! What do you think of putting a snatch block for the jib sheets on the toe rail (my jib car track doesn't go anywhere near the clew of my 104)?
 

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It is probably fine, but depends on the boat. How is the toe rail attached to the hull?

The jib car shouldn't be under the clew of the headsail, it should be behind it. A default place to start with the jib cars is having the line that extends forward from the sheet bisect the jib. If you have it too far forward the sheet will point up the leech of the sail and result in cupping. If it is too far back the sheet will point along the foot and flatten the foot and allow wind to spill out of the top.
 

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i wouldnt put jib sheets on the toe rail unless you have a steel boat in a storm the last thing you need is your toerail tearing out it may sink you.
 

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The ability of a sailboat to point is directly related to its speed. When you are sailing closehauled in heavy weather, the crashing of the waves on the bow greatly reduces it's speed, and consequently, it's pointing ability. You need power in the sails to drive the boat through the waves and maximize it's speed. On a masthead-rigged boat, like your Kent Ranger 24, the mainsail produces more heeling force, which helps keep the boat oriented to windward, but the jib provides by far the most forward-driving force, which helps drive the boat through the waves.

When you were sailing on a beam reach, the waves weren't pounding nearly so violently against the bow, and you didn't need as much power from the jib to drive it through. But, if you had hardened your course to windward, your boat speed would have dropped, and the decline in speed would have been accompanied by a reduced ability to point.
 

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As mentioned, your headsails are your main 'engines' in this rig configuration. The luff of the headsail is much cleaner and a more efficient entry than the main, which has the bulk of the mast disrupting flow.

With a proper balance of jib and main in a breeze your helm will be lighter, boat speed higher and your vmg to weather much better.

I think using the toerail will be fine, but your jib lead will be outboard which may widen your sheeting angle and limit pointing ability. When positioning your block remember that an extension of the sheet angle(block to clew) should roughly intersect mid-luff.
 

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Discussion Starter #9
This article is a pretty good summary of sail trim:
Sail Trim 101
Great stuff. Of all the books and magazine articles I've read this is the clearest, most concise summary of sail trim I've come across. As much as I love the Annapolis Book of Seamanship and the ASA textbooks, this tops them both.
 

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So, is a blown out headsail more detrimental to pointing higher than a blown out main...??
 

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So, is a blown out headsail more detrimental to pointing higher than a blown out main...??
Depending on rig configuration, the simple answer is probably YES.... ;)
 

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Thanks! What do you think of putting a snatch block for the jib sheets on the toe rail (my jib car track doesn't go anywhere near the clew of my 104)?
Snatch blocks for the jib sheets on the toe rail are the standard configuration on my 1980 Hunter 30 and have never been an issue.
 

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Depending on rig configuration, the simple answer is probably YES.... ;)
Interesting, keep in mind, I know nothing and didn't even stay in a Holiday Inn last night :laugher

But just the other day I had an instructor tell me the exact opposite :confused:

It didn't seem to make sense that's why I asked the forum...IDK
 

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IMO a stretched out "blown" headsail will have a wider entry angle even when sheeted in hard, forcing you to bear off some degrees to keep the telltales flying and flow "attached". This prevents you from pointing as high as a new sail with a flatter entry. In the OPs case, he has a typical IOR influenced rig with a very skinny main and the bulk of the power in the relatively large headsails, exaggerating the effects.

On our boat, a rather severe frac, we'd be more impacted with a blown main, probably, but still adversely affected with a bad headsail...
 

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Depending on rig configuration, the simple answer is probably YES.... ;)
Probably the most accurate answer!

Masthead rigs require a headsail more than fractionals... but it's only because the center of effort moves further forward on the mastheads with headsail. Actually it's more than that, you can "look" at the standard rig (100% jib and full up main), and see where the CofE basically is by the "middle" of the square footage of sail area.

The objective with pointing is a combination of a balanced sail rig, that provides enough power and lift to keep moving, one must move to create lift. POINT, is the result of headway, sailtrim, faired foils, rig tune, how one sails, and sea state. It's why people with identical boats can't always point the same.

By the way there is a lot MORE to point than just movement forward... and as stated above. A certain amount of lift is also created depending on movement of air against the curve of the back of the main, entry angle to both sails, luff curve, etc etc etc. A very respected racer came to talk to our small little pond of racers... someone asked how to get better point... and his response was a classic, he said "change everything!" His list of things to "improve" was pretty much every foil, or trim piece, or sail cut on the boat.

I suspect the old genoa you are using from the US25 is hurting you, either because of cut, or because it's blown (or more likely both). Using a snatch block as a barber hauler is a "temporary fix" and should not be your solution going forward, but on a light enough day it should answer your question if it's car location that is causing your problem (so you know where to locate a new T-track). I suspect it'd be less effort/cost to get a headsail cut for the boat.
 

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If you want to get in up to your armpits in it, read this article by a research aerodynamicist.

http://zaimov.eu/guides/Yacht - The Aerodynamics Of Sail Interaction.pdf

I've pulled out the summary of it all.

The major effects of the jib on the mainsail are as
follows:

1. The jib causes the stagnation point on the mainsail to
shift around toward the leading edge of the main (the
header effect).

2. As a result of the above, the peak suction velocities on
the lee side of the main from the main leading edge to
the area of the jib trailing edge are greatly reduced.
Since the peak suction velocities are reduced, the
recovery adverse pressures are also lower.

3. Because of the reduced pressure gradients on the
mainsail, the chances of the boundary layer separating
and the airfoil stalling are reduced.

4. The mainsail can be operated efficiently at higher
angles of attack without flow separation and stalling
than would be the case with the mainsail alone.

5. As the jib is sheeted in at closer angles to the centerline
of the boat (or as the mainsail is sheeted farther out) we
would get a continuing decrease in the suction
pressures on the lee side of the mainsail. When the
pressures on the windward and leeward side of the
mainsail become equal we no longer have the pressure
difference across the sail necessary to maintain the
airfoil and the sail begins to luff.

6. Much less air goes between the headstay and the mast
when the jib is placed in front of the mainsail. The
circulations of the mainsail and the jib tend to oppose
and cancel each other in the area between the two
sails. More air is, therefore, forced over the top (lee
side) of the jib.

7. The mainsail in the example used in this study could
have been trimmed closer to the centerline to load it up
more.


The major effects of the mainsail on the jib are as
follows:


1. The upwash flow ahead of the mainsail causes the
stagnation point on the jib to be shifted around toward
the windward side of the sail. The boat must,
therefore, be pointed closer to the wind with both
main and jib raised to prevent the jib from stalling.

2. The trailing edge (leech) of the jib is in a high speed
region of the flow about the mainsail. The trailing edge
velocity on the jib is, therefore, higher than if the jib is
used alone.

3. Because of the higher trailing edge velocity, the
velocities along the entire lee surface of the jib are
greatly increased when both the jib and main are used.
This contributes to the high efficiency of the jib as
observed by sailors.

4. Because of the above items we would expect that the
proper trim and shape of the mainsail can significantly
affect the efficiency and amount of driving force
obtained from the overlapping job. Anything that
would cause a reduction of velocity in the region of the
trailing edge of the jib would result in a lower driving
force contribution from the jib.

5. The mast in front of the mainsail has always been
blamed for causing the main to be less efficient than
the jib. From the above studies we have seen that this is
only part of the answer. The other, and probably
equally important factor, is the increased velocities on
the jib because its Kutta condition must be satisfied in a
locally high speed flow region created by the mainsail.
 

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Since pointing is all about developing maximum boat speed, there's a limit to how much benefit you can get from good sail trim. After your sails are in optimal trim, then you can still improve boat speed (and pointing) even more by reducing drag. You can reduce drag by reducing heel, balancing the pressures on the sails fore and aft of the Center of Lateral Resitance (CLR), and by good helmsmanship.
 

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.. and then there's 'pointing' and 'VMG to weather'..

You could, on many designs, rearrange the tracks and deck hardware to narrow your sheeting angle and buy new sails.. go out and 'see', say, 5-10 degrees better apparent wind angle.. only to find the boat's underbody will not support that working angle and the boat suffers so much leeway that any perceived improvement in 'pointing' is nullified by slip sliding sideways.. resulting in not getting upwind as fast as before..

It's the whole package, combined with a clean bottom, good prop, and boat handling/steering skills that will ultimately get you there... The first 80% of all that is pretty easy.. the last 10% not so much...
 

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I have to say this has been one of the most thorough threads I've seen yet on pointing ability!
 

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While we're talking about pointing, I'm curious if anyone who has switched to a feathering prop can comment on how much of a difference it made in pointing. The drag can't be good.

Yes, I'm looking for more reasons to justify a $2500 prop.
 
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