Re: 120 degr angle/staysails

Posted by Tom Vesey (tvesey@…>)
I have a small staysail on my Freedom 44 – 282 square feet – and it makes a substantial difference when reaching in a reasonable breeze. I was thinking about getting something larger, maybe 500-600 square feet for lighter winds. But if Michel’s talking about a sail that is the same area as main and mizzen together, maybe I’m not fulfilling my potential (as my teachers used to say) and should aim much higher! The gennaker he’s talking must be around 1,000 square feet or more on an F44.TomOn Mar 19, 2006, at 7:28 AM, michel.capel wrote: Lance, I don’t know if you have any, but staysails are really helpful on these angles of sail if it’s blowing under 20 kts. I just ordered a standard sized all-round (i.e. medium full, for 90* - 150* apparent wind) gennaker with sock to use as a mizzen staysail. These ready made sails are competitively priced and fit fine. Alternatively, you could try and find a second hand spinnaker and have the leech shortened with 3 or 4’ to change it into a gennaker. That will result in a full headed sail, very good on courses of 120* - 170* apparent wind. As a general rule, you could aim for a sail with about the same area as your main and mizzen together. Even your full displacement F40 can be persuaded to fly with one of these sails! Michel — In freedomyachts2003@yahoogroups.com, “lance_ryley” <lance_ryley@…> wrote: > > Thanks - for me, that was really the only point to the exercise - to > see if I could make Excel plot a polar graph. I already love my boat > and don’t need the numbers to tell me that. Although they may come > in handy next year when my wife and I do Marblehead to Halifax - not > as absolutes, but over a distance race like that, knowing, for > instance, that the fastest point of sail for the Cat Ketch seems to > be around 120 degrees off true wind angle might help to minimize the > time between showers. > > Bright Star > > — In freedomyachts2003@yahoogroups.com, “michel.capel” > <michel.capel@> wrote: > > > > Lance, nice work! I never got to making the graphs, but yesterday, > > while reading the discussion, I thought I might add the graphs. > > > > — In freedomyachts2003@yahoogroups.com, “lance_ryley” > > <lance_ryley@> wrote: > > > > > > I took Mike_c_f35ck’s polar plot excel file and added the plots > to > > > them to show them graphically. It’s in files under “f44 40 35 ck > > > polars with plots.” I didn’t change any of the numbers - mostly > did > > it > > > to see if Excel could do a polar graph. It can, as long as you > don’t > > > tell it what you’re doing. > > > > > > SPONSORED LINKS Sailing schools Sailing instruction Sailing lesson Sailing course Sailing adventure Sailing YAHOO! GROUPS LINKS Visit your group “freedomyachts2003” on the web. To unsubscribe from this group, send an email to: freedomyachts2003-unsubscribe@yahoogroups.com Your use of Yahoo! Groups is subject to the Yahoo! Terms of Service.

Posted by michel.capel (michel.capel@…>)

Tom,

1000 sqft may be a bit large voor the Gennaker.

I have the following measurements for the gennaker:

length of mizzen above deck (I-measure) = 14m = 46’
distance between mizzen and main (J-measure) = 6,2m = 20’

The gennaker I choose has a:
luff of 13,8m = 45’
leech of 12,8m = 42’
foot of 7,3m = 24’
The area is 82,6 m2 = 889 sqft.

It’s a ready made sail from Momentum sails. (www.momentum.com)

The maximum luff length is influenced by the sock (adds 1’) and the
fact that you need to be able to stretch the luff between mizzen top
and deck (with the tack halfway between main and mizzen) on higher
courses of around 90* to the apparent wind. On these courses, you
have to lower the tack or raise the clew to make sure the leech of
the gennaker opens and lets go of the wind. If the leech is too
tight on higher courses, you just create heel and backwash against
the mizzen.

You sheet the gennaker to the end of the mizzen boom. You should
have an ajustable line at the tack to raise or lower the tack to
stretch or unstretch the luff. You can also loosen the halyard to
create even fuller roach in the luff on off wind courses.

Michel
— In freedomyachts2003@yahoogroups.com, Tom Vesey <tvesey@…>
wrote:

I have a small staysail on my Freedom 44 – 282 square feet – and
it
makes a substantial difference when reaching in a reasonable
breeze.

I was thinking about getting something larger, maybe 500-600
square
feet for lighter winds.

But if Michel’s talking about a sail that is the same area as
main
and mizzen together, maybe I’m not fulfilling my potential (as my
teachers used to say) and should aim much higher! The gennaker
he’s
talking must be around 1,000 square feet or more on an F44.

Tom

On Mar 19, 2006, at 7:28 AM, michel.capel wrote:

Lance, I don’t know if you have any, but staysails are really
helpful on these angles of sail if it’s blowing under 20 kts. I
just
ordered a standard sized all-round (i.e. medium full, for 90* -
150*
apparent wind) gennaker with sock to use as a mizzen staysail.
These
ready made sails are competitively priced and fit fine.

Alternatively, you could try and find a second hand spinnaker and
have the leech shortened with 3 or 4’ to change it into a
gennaker.
That will result in a full headed sail, very good on courses of
120* - 170* apparent wind. As a general rule, you could aim for a
sail with about the same area as your main and mizzen together.

Even your full displacement F40 can be persuaded to fly with one
of
these sails!

Michel

— In freedomyachts2003@yahoogroups.com, “lance_ryley”
<lance_ryley@> wrote:

Thanks - for me, that was really the only point to the
exercise -
to
see if I could make Excel plot a polar graph. I already love my
boat
and don’t need the numbers to tell me that. Although they may
come
in handy next year when my wife and I do Marblehead to
Halifax -
not
as absolutes, but over a distance race like that, knowing, for
instance, that the fastest point of sail for the Cat Ketch
seems
to
be around 120 degrees off true wind angle might help to
minimize
the
time between showers.

Bright Star

— In freedomyachts2003@yahoogroups.com, “michel.capel”
<michel.capel@> wrote:

Lance, nice work! I never got to making the graphs, but
yesterday,
while reading the discussion, I thought I might add the
graphs.

— In freedomyachts2003@yahoogroups.com, “lance_ryley”
<lance_ryley@> wrote:

I took Mike_c_f35ck’s polar plot excel file and added the
plots
to
them to show them graphically. It’s in files under “f44 40
35
ck
polars with plots.” I didn’t change any of the numbers -
mostly
did
it
to see if Excel could do a polar graph. It can, as long as
you
don’t
tell it what you’re doing.

SPONSORED LINKS
Sailing schools Sailing instruction Sailing lesson
Sailing course Sailing adventure Sailing

YAHOO! GROUPS LINKS

Visit your group “freedomyachts2003” on the web.

To unsubscribe from this group, send an email to:
freedomyachts2003-unsubscribe@yahoogroups.com

Your use of Yahoo! Groups is subject to the Yahoo! Terms of
Service.