Keels: On a Wing and a Prayer
 

Okay, kiddies....here's what I know about the keel of the 35s5....a
very interesting topic if certain clowns down muck it up!

1) It has more wetted surface than the standard keel. Sorry, Doug, but
I got the info from Beneteau last year. The pic of the keel I linked
was only to show you that the wing keel is indeed longer measuring back
from the leading edge. Add the wing surfaces, sides and bottom and it's
19% area increase. Does this add up to substantial added drag? Probably
not. But it remains a contributing factor.

2) As the boat heels, the wing keel gains draft, but has less leading
edge area than a deep keel and generally generates less lift. Still,
well heeled the wings should become more or less vertical and reduce
leeway.

3) The flat bottom section of a winged keel creates turbulence beneath
and this contributes to drag.

4) DDW the hull of the 35s5 is it's best friend for lifting any of it's
mass up out of the water. Forward of the keel there is a large
flattened area.

5) I've read several times that a wing keel is a type of bulb keel. In
boats like mine it's other important goal concentrate weight low, like
a bulb.

I have simply not sailed the 35s5 enough (or hard enough) to give my
impressions of the keel over existing owners, so I will defer to them.
Most (and many have sailed both keel versions) find windward ability
quite close to the deep fin. Most sailors appear to be impressed with
the 35s5's windward ability with few complaints through a broad
reach...where the wings are working to create lift/reduce slippage. But
DDW all you have is DRAG and TURBULANCE generated by the wings and flat
underside of the keel. I'll add to that by saying that the forces of
water against the wings DDW are hardly uniform in the real world. So
now any current not flowing from dead ahead or aft will push against
the wings creating possible leeway in some conditions. True, I'm
talking about generally subtle forces, but yet again a contributing
factor.

The wing's best qualities appear to be realized to windward. Indeed the
previous owner of my boat, who is a long time racer named the boat
Windward First for that very reason. To win a race he said you had to
clobber 'em upwind because the 35s5 was a dog DDW. Several owners have
faired the 35s5 wing with excellent results. I really have no interest
as I'm not interested in handicap racing. Heart of Gold is loads of fun
to sail...and that's fine.
So? Let's hear it!


RB
35s5
NY

Keels: On a Wing and a Prayer
 

Capt. Rob wrote:
Okay, kiddies....here's what I know about the keel of the 35s5....a
very interesting topic if certain clowns down muck it up!

1) It has more wetted surface than the standard keel. Sorry, Doug, but
I got the info from Beneteau last year. The pic of the keel I linked
was only to show you that the wing keel is indeed longer measuring back
from the leading edge. Add the wing surfaces, sides and bottom and it's
19% area increase. Does this add up to substantial added drag? Probably
not. But it remains a contributing factor.

2) As the boat heels, the wing keel gains draft, but has less leading
edge area than a deep keel and generally generates less lift. Still,
well heeled the wings should become more or less vertical and reduce
leeway.

3) The flat bottom section of a winged keel creates turbulence beneath
and this contributes to drag.

4) DDW the hull of the 35s5 is it's best friend for lifting any of it's
mass up out of the water. Forward of the keel there is a large
flattened area.

5) I've read several times that a wing keel is a type of bulb keel. In
boats like mine it's other important goal concentrate weight low, like
a bulb.

I have simply not sailed the 35s5 enough (or hard enough) to give my
impressions of the keel over existing owners, so I will defer to them.
Most (and many have sailed both keel versions) find windward ability
quite close to the deep fin. Most sailors appear to be impressed with
the 35s5's windward ability with few complaints through a broad
reach...where the wings are working to create lift/reduce slippage. But
DDW all you have is DRAG and TURBULANCE generated by the wings and flat
underside of the keel. I'll add to that by saying that the forces of
water against the wings DDW are hardly uniform in the real world. So
now any current not flowing from dead ahead or aft will push against
the wings creating possible leeway in some conditions. True, I'm
talking about generally subtle forces, but yet again a contributing
factor.

The wing's best qualities appear to be realized to windward. Indeed the
previous owner of my boat, who is a long time racer named the boat
Windward First for that very reason. To win a race he said you had to
clobber 'em upwind because the 35s5 was a dog DDW. Several owners have
faired the 35s5 wing with excellent results. I really have no interest
as I'm not interested in handicap racing. Heart of Gold is loads of fun
to sail...and that's fine.
So? Let's hear it!


RB
35s5
NY

Very good report.

Joe

Keels: On a Wing and a Prayer
 

Nutsy,

Your 35-5 is not a dog downwind because of her keel. It is because of
that large tall main sail mounted mid ship. My Friends Benny is a damn
dog downwind and it has a deep fin keel. There is a real need for sail
pressure forward and reduced pressure on the main. The boat is
squirrelly down wind or even a broad reach.




http://community.webtv.net/tassail/ThomPage

Keels: On a Wing and a Prayer
 

Nutsy,

If you'd sail that boat and give that aeronautical section of that wing
a chance to work, you'll find that as you pick up speed the boat will
stiffen up; even gain righting force due to the lift on that wing. Not
only is it deeper, it is creating lift on the wing where it has the most
leverage (lowest) The more water flowing over that wing, the more
righting force to give you more upright sail to give you more power to
go faster. That is the theory of the Wing Keel. Learn to sail it Nutsy.
It begging to teach you, She'll fly at 20 degree heel and show you
righting force.




http://community.webtv.net/tassail/ThomPage

Keels: On a Wing and a Prayer
 

3 I don't believe!.When you heel the under side of the keel has a smooth
flow as does the top. The leading edge pushes the water up and away from
from the top surface,causing the stagnate water to rush in an off the
trailing edge. It isn't until after it leaves the wing that it becomes
turbulent (forming a cart wheel in the space behind the wing. Try the
bath tub with a layer of powder. run a ruler through it and watch the
action. Try to think of Newton rather than Bernouilli when you do it.




http://community.webtv.net/tassail/ThomPage

Keels: On a Wing and a Prayer
 

3 I don't believe!.When you heel the under side of the keel has a
smooth
flow as does the top.

I was referring to DDW, Thom.


RB
35s5
NY

Keels: On a Wing and a Prayer
 

Nutsy,

Wrong again! DDW will be as close or even dead on "Laminar Flow" as
you're going to get.

Only problem with a wing downwind is the increase frontal area.




http://community.webtv.net/tassail/ThomPage