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post #31 of 85 Old 02-17-2019
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Re: sailing past close hauled?

Ever noticed that in all the years sailboats have been on the drawing boards and on the water... no one has managed to get one to sail directly into the wind or very close to that... and sailboats have to tack???
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post #32 of 85 Old 02-17-2019
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Re: sailing past close hauled?

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Originally Posted by serpa4 View Post
Why can't you set your sails past close hulled to point more into the wind than 30 to 35? My assumption...too much wind resistance and you make no progress. 2 faster to fall off and go faster than if you sailed slower into the wind.

This is best answered by experimenting while you are sailing. I could probably cobble together an explanation but it wouldn't be as clear trying it on a sailboat. Sailing involves some complicated physics. One thing which isn't initially obvious is that the forward progress of a sailboat is the sum of 2 vectors, The sideways force of the sail and the sideways force of the keel combine to add up to a forward force. They squeeze from each size, resulting in a move forward. They are not equal.

So, in a static thing like a building, the forces always add up to zero. otherwise it would move. The sum of all forces in a sailboat is not zero, its a little bit of forward movement.
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post #33 of 85 Old 02-17-2019
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Re: sailing past close hauled?

And it's very difficult to see leeway.

By eye or by the plotter at the helm. It's tricky and misleading. If it's possible to see it in sheltered waters it's difficult to see it at sea.
You certainly can't adjust the sails to it.
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post #34 of 85 Old 02-17-2019
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Re: sailing past close hauled?

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Originally Posted by MarkofSeaLife View Post
And it's very difficult to see leeway.

By eye or by the plotter at the helm. It's tricky and misleading. If it's possible to see it in sheltered waters it's difficult to see it at sea.
You certainly can't adjust the sails to it.
I notice it when tacking close to land and the point on land that I THINK I was heading for is slipping to windward
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post #35 of 85 Old 02-17-2019
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Re: sailing past close hauled?

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Originally Posted by MarkofSeaLife View Post
And it's very difficult to see leeway.

By eye or by the plotter at the helm. It's tricky and misleading. If it's possible to see it in sheltered waters it's difficult to see it at sea.
You certainly can't adjust the sails to it.
On plotter you have waypoint plotted...and that bearing.
As you go, compare bearing and heading with the plot, and you have off track error to watch.
You can 'see' it if you understand the readouts.
Will also show current
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post #36 of 85 Old 02-17-2019
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Re: sailing past close hauled?

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Originally Posted by Sal Paradise View Post
...One thing which isn't initially obvious is that the forward progress of a sailboat is the sum of 2 vectors, The sideways force of the sail and the sideways force of the keel combine to add up to a forward force.....
I think of the sideways vector being countered by the keel, not summed, leaving the forward vector to propel the boat. Some keels do a better job of this countering and have less leeway, as a result.

The OP might think of these vectors this way. As you come up on the wind, the sail must be moved closer to the center of the boat. This makes the sideways vector grow and the forward vector decline (also the reason for heeling). Even if you could maintain sail shape right up to dead on the wind (which of course you can't), you would only have side vector and no forward vector. Certainly, as you even approach this mythical point of sail, the forward vector diminishes to the point that it won't overcome the friction of the hull anyway.
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post #37 of 85 Old 02-17-2019
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Re: sailing past close hauled?

OK... a crazy idea...

Suppose the mast was an air foil but horizontal like the wing of a plane. Wind coming over the bow would create lift and a small vector forward (maybe) the list could raise the boat but perhaps the forward vector was enough to pull the boat forward. Probably need a stiff breeze.

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post #38 of 85 Old 02-18-2019
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Re: sailing past close hauled?

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Originally Posted by SanderO View Post
OK... a crazy idea...

Suppose the mast was an air foil but horizontal like the wing of a plane. Wind coming over the bow would create lift and a small vector forward (maybe) the list could raise the boat but perhaps the forward vector was enough to pull the boat forward. Probably need a stiff breeze.
BUMP...

So let's get some of your geniuses to think out side the box.

If I take my sail on my boat and rotate the rig 90 so the leading edge of the sail is athwarship... and the mast is set say 15' above the deck level... the boom instead of rotating about a vertical axis... would be attached to the mast and rotate about a horizontal axis.

If the boom end was "sheeted" down the sail would be much like a plane wing. You could actually have e small mains... one to stbd and one to port. The sail could be reduced in size so the OAL beam less than the hoist. The nast would also rotate so the it could be stored fore and aft

So you use the motor to turn the bow dead to wind.... 0. the wind hits the sail and flows over the top surface which acts the same way it would if vertical... This generates lift... mostly up but some forward.. just as it does in a sloop rig. Would this lift be adequate to pull the boat through the water directly into the wind?

If so not, why not and if so why so.

If it is to work what sort of boat speeds are needed? No need for keel I would think because there are no aerodynamic forces which are not generated other than on the CL?

Could this rig sail off the wind? Perhaps rotating the mast so it stays normal to the wind direction and the bow moves to the direction you want to go... obviously only works on wind angles forward of the beam.. and as you get closer to the beam reach your rig works less and less... like sailing a normal rig dead into the wind.

Maybe to sail this rig downwind you raise the boom and the
"underside" of the sail fills

Of course this is a thought experiment... about getting the wind to generate lift so the boat can sail directly into to wind... not intended as a practical idea.

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Last edited by SanderO; 02-18-2019 at 06:56 AM.
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post #39 of 85 Old 02-18-2019
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Re: sailing past close hauled?

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Re: sailing past close hauled?

I think SO is pondering a horizontal wing sail. I believe in such a scenario, there is no forward vector. Think about the angle of attack of a wing making lift.


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Last edited by Minnewaska; 02-18-2019 at 07:32 AM.
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