Hi, Glenn, and thanks for your input (crossposted to RBB). I've left the
original thread attached to bring the RBBs up to speed.

Since you're building one, and have done extensive research on all aspects
of your boat, I'm interested to know what you'll do about a keel for RUTU
(apologies if it's been covered already some time in the past - I don't get
over to 'building' very often).

I'm also interested in your opinion, if you have one, of Mars Metals'
approaches to afterfits, and, if you've had any exposure to the
modifications I'm speaking of. Anecdotal experience suggests that it's a
neutral effect, or, worse, frequently, a negative effect. Of course,
perhaps the add-ons already identified were homegrown, and Mars Metals'
approach is engineered, which, of course, would make a tremendous
difference.

Thanks.

L8R

Skip

--
"Twenty years from now you will be more disappointed by the things you
didn't do than by the ones you did do. So throw off the bowlines. Sail away
from the safe harbor. Catch the trade winds in your sails. Explore. Dream.
Discover." - Mark Twain
"Glenn Ashmore" wrote in message
news:OAjEb.6979$JD6.5687@lakeread04...
The Scheel keel was developed back in the '60s but you don't see them as
often anymore. I know pacific Seacraft and a few other builders still
offer a Scheel option. The flaired camber at the botom adds weight down
low which imcreases righting moment for the same amount of draft.
Theoretically it also increases lift but increasing lift down low sounds
counter-productive to me. The outward flair and wide slow convex bottom
also disrupts the formation of the tip vortex to a limited degree.

The advent of bulbs and wings reduced the attractiveness of Scheel
keels. Besides adding more weight down low while maintaining the
thinner camber and shorter cord, bulbs also act as an end plate reducing
the tip vortex better than the Scheel and therefore total drag.

Skip Gundlach wrote:

So, we're looking at boats, and Henry Scheel comes to light. He's
patented
a keel that several manufacturers are paying royalties to use, and what
I
read suggest that rigorous tank testing holds out the superiority to
straight keels, so, presumably, it must be worth *something*...

However, just a Henry Scheel design does not a Scheel keel include. Too
bad...

For those not familiar, it's got some of the attributes of a wing and
some
of a bulb, but primarily greatly increases holding power and reduces
vortex
drag over that of a standard keel, particularly beneficial to a shoal
draft
need, without the anchor-digging-in attributes of a wing.

So, the boats I'm looking at don't have this keel. I've read of those
cutting off the bottom of a straight keel and adding a bulb, or
equivalent,
to achieve a shoal draft with the same equivalent weight. They've done
this
perhaps by somehow attaching at the bottom, or, as one site I
discovered,
bolting two lead halves to the remaining keel, forming sort of a bulb
wing.

Now to the question. Have any of you done, or know someone who has, an
addition of such a bulb/wing to an *existing* - not shortened - keel?
The
benefits I'd see are better holding, and more ballast, as low as
possible,
against a minimal overall increase in weight (projected is from 30000 to
maybe 32/33000 pounds displacement, with that increase also applying to
the
current 8400# ballast, light by my thought).

I'm more interested in experience stories, if there are any, or
engineering
reasons for or against, as opposed to 'I think it would...' information.

Thanks.

L8R

Skip (and Lydia)



--
Glenn Ashmore

I'm building a 45' cutter in strip/composite. Watch my progress (or lack
there of) at: http://www.rutuonline.com
Shameless Commercial Division: http://www.spade-anchor-us.com