Earlier I raised some questions on the use of The Omer Wing Sail on multihulls. I send the same questions to Mr. Ilan Gonen from the co. Mr. Gonen. His answers can be read here under should anybody have the interest:
Thanks for your interest in Omer
wing sail and for the compliments. Usually, sailors are very conservative, and
it was very refreshing to read your comments.
The truth is that I have no
experience in multi hulls, however, I had a lot of ideas exchanges with multi
hull owners who, like you, considered having a wing sail.
You were right about the bigger heeling moment on your cat mast. The simple answer to that is that the mast should be designed to hold these forces, meaning - it should have thicker walls, might be also bigger in diameter. Your boat's heeling moment should be the basis for the calculation. In general, there is no problem to build such a mast.
You were right about the bigger heeling moment on your cat mast. The simple answer to that is that the mast should be designed to hold these forces, meaning - it should have thicker walls, might be also bigger in diameter. Your boat's heeling moment should be the basis for the calculation. In general, there is no problem to build such a mast.
The second issue concerning free
standing mast on cats is the hull. The must foot should be inside the hull in
order to have two holding points. The mast foot is a ball, put into a "bowl"
fixed the hull's bottom. The second point is a roller bearing, fixed to the deck
(in the case of mono hulls). Big cats that have enough room in the center area
can do it. I am not sure that it is the same situation with small
cats.
There were no problems sailing in
strong winds since you reef the wing exactly like you reef a main sail. We
sailed the wing at 30 knots wind, two reefs down, easy.
To my mind, the best for cats is
to have twin rig (a mast on each of the hulls). In this case the wing each wing
is smaller and easier to handle, smaller mast thickness, the risk of capsize is
minimal, the boats performance in terms of up wind sailing is much better as
well as in terms of boat's speed.
Hope I helped in bringing some
more understanding of the concept.
Best regards
Ilan
OMER wing sail Ltd
23 Hohit
St. Ramat hasharon
ISRAEL
47226
Tel: +972
3 5401675
Mobile:
+972 54 4277617
Email: ilan@omerwingsail.com
Web
site: www.omerwingsail.com
2008/3/26, gunnar.westholm <gunnar.westholm@gmail.com >:
You cant compare wharram to harryproa. Wharram are a "timeless"
building method.
I own a Tiki21, and it's the perfect rugged tool for exploring the
thight and shallows, in the scandinavian archipelagos..
A harry type proadesign, built on the wharram plywood construction
would be very interesting for the homebuilder.
I agree that the future of kites will be very interesting. I'm into
all sorts of kitesailing, mostly on snow. I would really like to try
an OutLeader on our Tiki..
/Gunnar
--- In harryproa@yahoogroups.com.au , "proadude" <rbmaui@...> wrote:
>
> ...wharram is not the best example of the modern
multihull...harryproa
> is,so is the omer wing sail.With new technology and some positive
> thinking the future should be showing more of the wing sails
> development...and kites as well.Rob's telescoping mast should go
well
> with that...
> Richard
>
> --- In harryproa@yahoogroups.com.au , "gunnar.westholm"
> <gunnar.westholm@> wrote:
> >
> > More on the twin wing Tiki30 PHA
> > http://www.themultihull.com/ wharram2/ bf7.htm
> >
> > Mvh.
> > Gunnar
> >
> >
> > --- In harryproa@yahoogroups.com.au , "Jan Iversen" <pow.jiv@>
> > wrote:
> > >
> > > No dought that it will work wonderful on the multihull, as the
> > function of
> > > the sail is concerned. My worries goes to the unstayed mast and
the
> > somewhat
> > > "flimsy" construction of the soft sail profile. The rigging of
a
> > multihull
> > > has to stand up to much higher stress/forces than the one of a
mono
> > hull, as
> > > the multihull has much higher stabillity. So the question will
be:
> > can this
> > > very interesting rig be used on a cruising multihull
(catamaran),
> > or will
> > > the weight end up being too heavy? There are lots of other
> > attractive
> > > benefits to have with sail, absolutely interesting developement.
> > >
> > > Jan
> > >
> > > 2008/3/25, proadude <rbmaui@>:
> > > >
> > > > It may work even better on the multihull,since the apparent
> > wind is
> > > > forward most of the time...
> > > > Richard
> > > > --- In harryproa@yahoogroups.com.au <harryproa%
> > 40yahoogroups.com.au >, "Jan
> > > > Iversen" <pow.jiv@> wrote:
> > > > >
> > > > > Very interesting website!!! How can this be applyed to say
a
> > catamaran?
> > > > > Jan
> > > > >
> > > > > 2008/3/25, proadude <rbmaui@>:
> > > > > >
> > > > > > how about this for a change...if we want to complicate
things
> > even
> > > > > > more,but the effect may be pretty positive?!
> > > > > > Richard
> > > > > > www.omerwingsail.com/
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