Gaff sails?
 

Hi Tim,

I just looked at the main panel layout on Lady K. and it struck me that
the main seams were not running as I expected. What's the story?

Cheers MC

Gaff sails?
 

Either:

can you be more specific? Which photo, what were you expecting?

Or:

If referring to "vertical" seams: Vertical of course was
traditional, until cross-cut demonstrated its superiority in the
old fabrics. With dacron, I am told that unless one is seeking
the absolutely last iota of aerodynamic efficiency, the direction
of the seaming makes almost no difference at all with modern
materials, modern seaming and heavy cloth (which Lady Kates main
certainly is!). As it's a gaff sail, and one is giving up a
degree of aerodynamic and pointing perfection for a larger area
lower down (lower heeling moment/area) and ease of rigging and
handling, and to boot it as a tree-trunk at the leading edge, the
sail was vertical seamed. (the authority for "I am told" was Ken
O'Brien). There are also supposed to be advantages in the event
of a tear, but I don't believe that.

Flying Tadpole's gaff sails and flying jib mit club were also
vertically cut, but her main staysail cross-cut.

Flying Tadpole

The navigator© wrote:

Hi Tim,

I just looked at the main panel layout on Lady K. and it struck me that
the main seams were not running as I expected. What's the story?

Cheers MC

Gaff sails?
 

Yes, I was expecting cross cut as you are using Dacron. BUT seaming is
still very important... e.g.

http://woodsdesignssailingcatamarans.com/rigs.htm

" In the old days of cotton gaff sails the cloth was weak and thus seams
ran vertically so, if they tore, the sail would not break in half. With
the advent of Dacron/Terylene, cross cut sails came into vogue partly
because these were (and still are) cheap to produce. More recently
computer sail design packages and laser cutters have made it easy for
sail lofts to make sails with more exotic panel layouts. "

Nevertheless i would have thought that with an inefficient rig, sail
shape would be even more critical and twist/draft control very
important. Even though Lady Kate would go very well downwind with any
(or even no) sail don't you want a bit more going to wind -or are all
your ports downwind...

Cheers MC


Flying Tadpole wrote:
Either:

can you be more specific? Which photo, what were you expecting?

Or:

If referring to "vertical" seams: Vertical of course was
traditional, until cross-cut demonstrated its superiority in the
old fabrics. With dacron, I am told that unless one is seeking
the absolutely last iota of aerodynamic efficiency, the direction
of the seaming makes almost no difference at all with modern
materials, modern seaming and heavy cloth (which Lady Kates main
certainly is!). As it's a gaff sail, and one is giving up a
degree of aerodynamic and pointing perfection for a larger area
lower down (lower heeling moment/area) and ease of rigging and
handling, and to boot it as a tree-trunk at the leading edge, the
sail was vertical seamed. (the authority for "I am told" was Ken
O'Brien). There are also supposed to be advantages in the event
of a tear, but I don't believe that.

Flying Tadpole's gaff sails and flying jib mit club were also
vertically cut, but her main staysail cross-cut.

Flying Tadpole

The navigator© wrote:

Hi Tim,

I just looked at the main panel layout on Lady K. and it struck me that
the main seams were not running as I expected. What's the story?

Cheers MC

Gaff sails?
 

Well, MC, I agree with all you say, as it was also what I
thought. However, in the case of Flying Tadpole II (Lady Kate
already had her suit) I took the advice of the sailmaker instead,
possibly because, as the sailmaker responsible for breaking the
hearts of the NYYC I felt he might know more than I, or possibly
because he learnt a few things from his uncle Conor that I
mightn't know in relation to cruising sails.

Mind you, I normally refuse to bow to authority unless it's
approaching celestial, but in this case I did not feel my own
experience and thoughts were defensible...

BTW, you appear to be still defining "efficiency" purely in terms
of extracting the maximum degree of weatherliness (70 degrees?).
Being naturally indolent, I tend to regard an efficient rig as
one which limits the demands on crew, machinery, rigging and
hull, while still providing a good degree of weatherliness (90
degrees).

Flying Tadpole

The navigator© wrote:

Yes, I was expecting cross cut as you are using Dacron. BUT seaming is
still very important... e.g.

http://woodsdesignssailingcatamarans.com/rigs.htm

" In the old days of cotton gaff sails the cloth was weak and thus seams
ran vertically so, if they tore, the sail would not break in half. With
the advent of Dacron/Terylene, cross cut sails came into vogue partly
because these were (and still are) cheap to produce. More recently
computer sail design packages and laser cutters have made it easy for
sail lofts to make sails with more exotic panel layouts. "

Nevertheless i would have thought that with an inefficient rig, sail
shape would be even more critical and twist/draft control very
important. Even though Lady Kate would go very well downwind with any
(or even no) sail don't you want a bit more going to wind -or are all
your ports downwind...

Cheers MC

Flying Tadpole wrote:
Either:

can you be more specific? Which photo, what were you expecting?

Or:

If referring to "vertical" seams: Vertical of course was
traditional, until cross-cut demonstrated its superiority in the
old fabrics. With dacron, I am told that unless one is seeking
the absolutely last iota of aerodynamic efficiency, the direction
of the seaming makes almost no difference at all with modern
materials, modern seaming and heavy cloth (which Lady Kates main
certainly is!). As it's a gaff sail, and one is giving up a
degree of aerodynamic and pointing perfection for a larger area
lower down (lower heeling moment/area) and ease of rigging and
handling, and to boot it as a tree-trunk at the leading edge, the
sail was vertical seamed. (the authority for "I am told" was Ken
O'Brien). There are also supposed to be advantages in the event
of a tear, but I don't believe that.

Flying Tadpole's gaff sails and flying jib mit club were also
vertically cut, but her main staysail cross-cut.

Flying Tadpole

The navigator© wrote:

Hi Tim,

I just looked at the main panel layout on Lady K. and it struck me that
the main seams were not running as I expected. What's the story?

Cheers MC

Gaff sails?
 

The navigator© wrote:

I didn't realize that 'uncle conor' would know a lot about cruising
sails for gaff rigged boats!

"Saorise", although a brigantine, did have fore-and-aft sails
too. What you _should_ have queried was how old my sailmaker was
when his uncle was alive...

But in any case, can 90 degrees to the wind
be called going to windward? When one factors leeway, wouldn't you
always end up in a Jackass port? Weatherliness is close to Godliness!

Cruel of you to play in my indolent language in such a way, MC.
"Tacking through x degrees" was the intended implication, not "x
degrees to the wind". But you knew that.

I tried out the minimum 3 reef main with no mizzen in the
near-gale and chop of the other weekend. A mess. Lee helm and
all. 2.5mi gain in about 18mi on the map (two beats). With the
mizzen back in operation, not too bad at all, though I should
have let her foot a little more. I think I reported it last week
for the ng's edification, but it got lost in the subsequent DTs.

Flying Tadpole

Cheers MC

Flying Tadpole wrote:
Well, MC, I agree with all you say, as it was also what I
thought. However, in the case of Flying Tadpole II (Lady Kate
already had her suit) I took the advice of the sailmaker instead,
possibly because, as the sailmaker responsible for breaking the
hearts of the NYYC I felt he might know more than I, or possibly
because he learnt a few things from his uncle Conor that I
mightn't know in relation to cruising sails.

Mind you, I normally refuse to bow to authority unless it's
approaching celestial, but in this case I did not feel my own
experience and thoughts were defensible...

BTW, you appear to be still defining "efficiency" purely in terms
of extracting the maximum degree of weatherliness (70 degrees?).
Being naturally indolent, I tend to regard an efficient rig as
one which limits the demands on crew, machinery, rigging and
hull, while still providing a good degree of weatherliness (90
degrees).

Flying Tadpole

The navigator© wrote:

Yes, I was expecting cross cut as you are using Dacron. BUT seaming is
still very important... e.g.

http://woodsdesignssailingcatamarans.com/rigs.htm

" In the old days of cotton gaff sails the cloth was weak and thus seams
ran vertically so, if they tore, the sail would not break in half. With
the advent of Dacron/Terylene, cross cut sails came into vogue partly
because these were (and still are) cheap to produce. More recently
computer sail design packages and laser cutters have made it easy for
sail lofts to make sails with more exotic panel layouts. "

Nevertheless i would have thought that with an inefficient rig, sail
shape would be even more critical and twist/draft control very
important. Even though Lady Kate would go very well downwind with any
(or even no) sail don't you want a bit more going to wind -or are all
your ports downwind...

Cheers MC

Flying Tadpole wrote:

Either:

can you be more specific? Which photo, what were you expecting?

Or:

If referring to "vertical" seams: Vertical of course was
traditional, until cross-cut demonstrated its superiority in the
old fabrics. With dacron, I am told that unless one is seeking
the absolutely last iota of aerodynamic efficiency, the direction
of the seaming makes almost no difference at all with modern
materials, modern seaming and heavy cloth (which Lady Kates main
certainly is!). As it's a gaff sail, and one is giving up a
degree of aerodynamic and pointing perfection for a larger area
lower down (lower heeling moment/area) and ease of rigging and
handling, and to boot it as a tree-trunk at the leading edge, the
sail was vertical seamed. (the authority for "I am told" was Ken
O'Brien). There are also supposed to be advantages in the event
of a tear, but I don't believe that.

Flying Tadpole's gaff sails and flying jib mit club were also
vertically cut, but her main staysail cross-cut.

Flying Tadpole

The navigator© wrote:


Hi Tim,

I just looked at the main panel layout on Lady K. and it struck me that
the main seams were not running as I expected. What's the story?

Cheers MC

Gaff sails?
 

But it's the headsail that really drives to windward! What would have
happened under head and mizzen I wonder... While the deep reef main
would have helped sink her chine this might not help as much as one
would hope due to energy loss in the turbulence. Hmm an interesting
problem for which my trimming intuitions are ambivalent. Tack through 90
is fine but your leeway must be killing your VMG for such low figures
-right?

Cheers MC


Flying Tadpole wrote:

The navigator© wrote:

I didn't realize that 'uncle conor' would know a lot about cruising
sails for gaff rigged boats!


"Saorise", although a brigantine, did have fore-and-aft sails
too. What you _should_ have queried was how old my sailmaker was
when his uncle was alive...


But in any case, can 90 degrees to the wind
be called going to windward? When one factors leeway, wouldn't you
always end up in a Jackass port? Weatherliness is close to Godliness!


Cruel of you to play in my indolent language in such a way, MC.
"Tacking through x degrees" was the intended implication, not "x
degrees to the wind". But you knew that.

I tried out the minimum 3 reef main with no mizzen in the
near-gale and chop of the other weekend. A mess. Lee helm and
all. 2.5mi gain in about 18mi on the map (two beats). With the
mizzen back in operation, not too bad at all, though I should
have let her foot a little more. I think I reported it last week
for the ng's edification, but it got lost in the subsequent DTs.

Flying Tadpole

Cheers MC

Flying Tadpole wrote:

Well, MC, I agree with all you say, as it was also what I
thought. However, in the case of Flying Tadpole II (Lady Kate
already had her suit) I took the advice of the sailmaker instead,
possibly because, as the sailmaker responsible for breaking the
hearts of the NYYC I felt he might know more than I, or possibly
because he learnt a few things from his uncle Conor that I
mightn't know in relation to cruising sails.

Mind you, I normally refuse to bow to authority unless it's
approaching celestial, but in this case I did not feel my own
experience and thoughts were defensible...

BTW, you appear to be still defining "efficiency" purely in terms
of extracting the maximum degree of weatherliness (70 degrees?).
Being naturally indolent, I tend to regard an efficient rig as
one which limits the demands on crew, machinery, rigging and
hull, while still providing a good degree of weatherliness (90
degrees).

Flying Tadpole

The navigator© wrote:


Yes, I was expecting cross cut as you are using Dacron. BUT seaming is
still very important... e.g.

http://woodsdesignssailingcatamarans.com/rigs.htm

" In the old days of cotton gaff sails the cloth was weak and thus seams
ran vertically so, if they tore, the sail would not break in half. With
the advent of Dacron/Terylene, cross cut sails came into vogue partly
because these were (and still are) cheap to produce. More recently
computer sail design packages and laser cutters have made it easy for
sail lofts to make sails with more exotic panel layouts. "

Nevertheless i would have thought that with an inefficient rig, sail
shape would be even more critical and twist/draft control very
important. Even though Lady Kate would go very well downwind with any
(or even no) sail don't you want a bit more going to wind -or are all
your ports downwind...

Cheers MC

Flying Tadpole wrote:


Either:

can you be more specific? Which photo, what were you expecting?

Or:

If referring to "vertical" seams: Vertical of course was
traditional, until cross-cut demonstrated its superiority in the
old fabrics. With dacron, I am told that unless one is seeking
the absolutely last iota of aerodynamic efficiency, the direction
of the seaming makes almost no difference at all with modern
materials, modern seaming and heavy cloth (which Lady Kates main
certainly is!). As it's a gaff sail, and one is giving up a
degree of aerodynamic and pointing perfection for a larger area
lower down (lower heeling moment/area) and ease of rigging and
handling, and to boot it as a tree-trunk at the leading edge, the
sail was vertical seamed. (the authority for "I am told" was Ken
O'Brien). There are also supposed to be advantages in the event
of a tear, but I don't believe that.

Flying Tadpole's gaff sails and flying jib mit club were also
vertically cut, but her main staysail cross-cut.

Flying Tadpole

The navigator© wrote:



Hi Tim,

I just looked at the main panel layout on Lady K. and it struck me that
the main seams were not running as I expected. What's the story?

Cheers MC

Gaff sails?
 

Are you sure it's not 'Soarise' or 'IsaSore' ?

Cheers MC

Flying Tadpole wrote:
Sorry. I hate celtic transliteration. The name is "SAOIRSE"

Flying Tadpole wrote:

The navigator© wrote:

I didn't realize that 'uncle conor' would know a lot about cruising
sails for gaff rigged boats!

"Saorise", although a brigantine, did have fore-and-aft sails
too. What you _should_ have queried was how old my sailmaker was
when his uncle was alive...


But in any case, can 90 degrees to the wind
be called going to windward? When one factors leeway, wouldn't you
always end up in a Jackass port? Weatherliness is close to Godliness!

Cruel of you to play in my indolent language in such a way, MC.
"Tacking through x degrees" was the intended implication, not "x
degrees to the wind". But you knew that.

I tried out the minimum 3 reef main with no mizzen in the
near-gale and chop of the other weekend. A mess. Lee helm and
all. 2.5mi gain in about 18mi on the map (two beats). With the
mizzen back in operation, not too bad at all, though I should
have let her foot a little more. I think I reported it last week
for the ng's edification, but it got lost in the subsequent DTs.

Flying Tadpole

Cheers MC

Flying Tadpole wrote:

Well, MC, I agree with all you say, as it was also what I
thought. However, in the case of Flying Tadpole II (Lady Kate
already had her suit) I took the advice of the sailmaker instead,
possibly because, as the sailmaker responsible for breaking the
hearts of the NYYC I felt he might know more than I, or possibly
because he learnt a few things from his uncle Conor that I
mightn't know in relation to cruising sails.

Mind you, I normally refuse to bow to authority unless it's
approaching celestial, but in this case I did not feel my own
experience and thoughts were defensible...

BTW, you appear to be still defining "efficiency" purely in terms
of extracting the maximum degree of weatherliness (70 degrees?).
Being naturally indolent, I tend to regard an efficient rig as
one which limits the demands on crew, machinery, rigging and
hull, while still providing a good degree of weatherliness (90
degrees).

Flying Tadpole

The navigator© wrote:


Yes, I was expecting cross cut as you are using Dacron. BUT seaming is
still very important... e.g.

http://woodsdesignssailingcatamarans.com/rigs.htm

" In the old days of cotton gaff sails the cloth was weak and thus seams
ran vertically so, if they tore, the sail would not break in half. With
the advent of Dacron/Terylene, cross cut sails came into vogue partly
because these were (and still are) cheap to produce. More recently
computer sail design packages and laser cutters have made it easy for
sail lofts to make sails with more exotic panel layouts. "

Nevertheless i would have thought that with an inefficient rig, sail
shape would be even more critical and twist/draft control very
important. Even though Lady Kate would go very well downwind with any
(or even no) sail don't you want a bit more going to wind -or are all
your ports downwind...

Cheers MC

Flying Tadpole wrote:


Either:

can you be more specific? Which photo, what were you expecting?

Or:

If referring to "vertical" seams: Vertical of course was
traditional, until cross-cut demonstrated its superiority in the
old fabrics. With dacron, I am told that unless one is seeking
the absolutely last iota of aerodynamic efficiency, the direction
of the seaming makes almost no difference at all with modern
materials, modern seaming and heavy cloth (which Lady Kates main
certainly is!). As it's a gaff sail, and one is giving up a
degree of aerodynamic and pointing perfection for a larger area
lower down (lower heeling moment/area) and ease of rigging and
handling, and to boot it as a tree-trunk at the leading edge, the
sail was vertical seamed. (the authority for "I am told" was Ken
O'Brien). There are also supposed to be advantages in the event
of a tear, but I don't believe that.

Flying Tadpole's gaff sails and flying jib mit club were also
vertically cut, but her main staysail cross-cut.

Flying Tadpole

The navigator© wrote:



Hi Tim,

I just looked at the main panel layout on Lady K. and it struck me that
the main seams were not running as I expected. What's the story?

Cheers MC

Gaff sails?
 

In those conditions and rigged with only the 3reef main, killing
it almost stone dead. Tthe 2.5mi were gained in 4 hours. I
perservered with the experiment to see what would happen. It
certainly would have clawed off a lee shore but...Hove to in
rougher conditions (no I wasn't then trying to sail uphill) two
years ago, leeward drift was about 1knot.

The grip on the water and the leeway with a balanced rig up
normally isn't bad, even in turbulent stuff: what was the real
killer was stubbing toes on the very short-period, square chop
coming from multiple directions (all vaguely windward). A
classical sharpie underwater hull shape lifts quite nicely to
windward, the leeward chine dug in, the boards down etc. But, a
homely transom bow will really cop it sweet in a very short
chop. I'll have to persuade Oz1 to come out on a bad day just to
see how strange the chop is (you'll never believe me otherwise).

No grip is any good, on a shoal draft boat, when the whole lake
blows bodily to leeward, which I have also seen (tho fortunately
was not out in it...). Cecil B de Mille and his Biblical
swimming pool has nothing on it.

FT

The navigator© wrote:

But it's the headsail that really drives to windward! What would have
happened under head and mizzen I wonder... While the deep reef main
would have helped sink her chine this might not help as much as one
would hope due to energy loss in the turbulence. Hmm an interesting
problem for which my trimming intuitions are ambivalent. Tack through 90
is fine but your leeway must be killing your VMG for such low figures
-right?

Cheers MC

Flying Tadpole wrote:

The navigator© wrote:

I didn't realize that 'uncle conor' would know a lot about cruising
sails for gaff rigged boats!


"Saorise", although a brigantine, did have fore-and-aft sails
too. What you _should_ have queried was how old my sailmaker was
when his uncle was alive...


But in any case, can 90 degrees to the wind
be called going to windward? When one factors leeway, wouldn't you
always end up in a Jackass port? Weatherliness is close to Godliness!


Cruel of you to play in my indolent language in such a way, MC.
"Tacking through x degrees" was the intended implication, not "x
degrees to the wind". But you knew that.

I tried out the minimum 3 reef main with no mizzen in the
near-gale and chop of the other weekend. A mess. Lee helm and
all. 2.5mi gain in about 18mi on the map (two beats). With the
mizzen back in operation, not too bad at all, though I should
have let her foot a little more. I think I reported it last week
for the ng's edification, but it got lost in the subsequent DTs.

Flying Tadpole

Cheers MC

Flying Tadpole wrote:

Well, MC, I agree with all you say, as it was also what I
thought. However, in the case of Flying Tadpole II (Lady Kate
already had her suit) I took the advice of the sailmaker instead,
possibly because, as the sailmaker responsible for breaking the
hearts of the NYYC I felt he might know more than I, or possibly
because he learnt a few things from his uncle Conor that I
mightn't know in relation to cruising sails.

Mind you, I normally refuse to bow to authority unless it's
approaching celestial, but in this case I did not feel my own
experience and thoughts were defensible...

BTW, you appear to be still defining "efficiency" purely in terms
of extracting the maximum degree of weatherliness (70 degrees?).
Being naturally indolent, I tend to regard an efficient rig as
one which limits the demands on crew, machinery, rigging and
hull, while still providing a good degree of weatherliness (90
degrees).

Flying Tadpole

The navigator© wrote:


Yes, I was expecting cross cut as you are using Dacron. BUT seaming is
still very important... e.g.

http://woodsdesignssailingcatamarans.com/rigs.htm

" In the old days of cotton gaff sails the cloth was weak and thus seams
ran vertically so, if they tore, the sail would not break in half. With
the advent of Dacron/Terylene, cross cut sails came into vogue partly
because these were (and still are) cheap to produce. More recently
computer sail design packages and laser cutters have made it easy for
sail lofts to make sails with more exotic panel layouts. "

Nevertheless i would have thought that with an inefficient rig, sail
shape would be even more critical and twist/draft control very
important. Even though Lady Kate would go very well downwind with any
(or even no) sail don't you want a bit more going to wind -or are all
your ports downwind...

Cheers MC

Flying Tadpole wrote:


Either:

can you be more specific? Which photo, what were you expecting?

Or:

If referring to "vertical" seams: Vertical of course was
traditional, until cross-cut demonstrated its superiority in the
old fabrics. With dacron, I am told that unless one is seeking
the absolutely last iota of aerodynamic efficiency, the direction
of the seaming makes almost no difference at all with modern
materials, modern seaming and heavy cloth (which Lady Kates main
certainly is!). As it's a gaff sail, and one is giving up a
degree of aerodynamic and pointing perfection for a larger area
lower down (lower heeling moment/area) and ease of rigging and
handling, and to boot it as a tree-trunk at the leading edge, the
sail was vertical seamed. (the authority for "I am told" was Ken
O'Brien). There are also supposed to be advantages in the event
of a tear, but I don't believe that.

Flying Tadpole's gaff sails and flying jib mit club were also
vertically cut, but her main staysail cross-cut.

Flying Tadpole

The navigator© wrote:



Hi Tim,

I just looked at the main panel layout on Lady K. and it struck me that
the main seams were not running as I expected. What's the story?

Cheers MC

Gaff sails?
 

I just try to duplicate the spelling I see:

Google Search:
The Circumnavigators - by Don Holm - Appendix - Ch 42 - Around 3
....
.... The first known yachtsman to circumnavigate via a]l three
capes was the puckish Irishman,
Conor O'Brien, on Saoirse in 1923-1925, east- about, making the
whole ...
http://www.mcallen.lib.tx.us/books/c...a/ci_42cap.htm - 18k - Cached
- Similar pages

The navigator© wrote:

Are you sure it's not 'Soarise' or 'IsaSore' ?

Cheers MC

Flying Tadpole wrote:
Sorry. I hate celtic transliteration. The name is "SAOIRSE"

Flying Tadpole wrote:

The navigator© wrote:

I didn't realize that 'uncle conor' would know a lot about cruising
sails for gaff rigged boats!

"Saorise", although a brigantine, did have fore-and-aft sails
too. What you _should_ have queried was how old my sailmaker was
when his uncle was alive...


But in any case, can 90 degrees to the wind
be called going to windward? When one factors leeway, wouldn't you
always end up in a Jackass port? Weatherliness is close to Godliness!

Cruel of you to play in my indolent language in such a way, MC.
"Tacking through x degrees" was the intended implication, not "x
degrees to the wind". But you knew that.

I tried out the minimum 3 reef main with no mizzen in the
near-gale and chop of the other weekend. A mess. Lee helm and
all. 2.5mi gain in about 18mi on the map (two beats). With the
mizzen back in operation, not too bad at all, though I should
have let her foot a little more. I think I reported it last week
for the ng's edification, but it got lost in the subsequent DTs.

Flying Tadpole

Cheers MC

Flying Tadpole wrote:

Well, MC, I agree with all you say, as it was also what I
thought. However, in the case of Flying Tadpole II (Lady Kate
already had her suit) I took the advice of the sailmaker instead,
possibly because, as the sailmaker responsible for breaking the
hearts of the NYYC I felt he might know more than I, or possibly
because he learnt a few things from his uncle Conor that I
mightn't know in relation to cruising sails.

Mind you, I normally refuse to bow to authority unless it's
approaching celestial, but in this case I did not feel my own
experience and thoughts were defensible...

BTW, you appear to be still defining "efficiency" purely in terms
of extracting the maximum degree of weatherliness (70 degrees?).
Being naturally indolent, I tend to regard an efficient rig as
one which limits the demands on crew, machinery, rigging and
hull, while still providing a good degree of weatherliness (90
degrees).

Flying Tadpole

The navigator© wrote:


Yes, I was expecting cross cut as you are using Dacron. BUT seaming is
still very important... e.g.

http://woodsdesignssailingcatamarans.com/rigs.htm

" In the old days of cotton gaff sails the cloth was weak and thus seams
ran vertically so, if they tore, the sail would not break in half. With
the advent of Dacron/Terylene, cross cut sails came into vogue partly
because these were (and still are) cheap to produce. More recently
computer sail design packages and laser cutters have made it easy for
sail lofts to make sails with more exotic panel layouts. "

Nevertheless i would have thought that with an inefficient rig, sail
shape would be even more critical and twist/draft control very
important. Even though Lady Kate would go very well downwind with any
(or even no) sail don't you want a bit more going to wind -or are all
your ports downwind...

Cheers MC

Flying Tadpole wrote:


Either:

can you be more specific? Which photo, what were you expecting?

Or:

If referring to "vertical" seams: Vertical of course was
traditional, until cross-cut demonstrated its superiority in the
old fabrics. With dacron, I am told that unless one is seeking
the absolutely last iota of aerodynamic efficiency, the direction
of the seaming makes almost no difference at all with modern
materials, modern seaming and heavy cloth (which Lady Kates main
certainly is!). As it's a gaff sail, and one is giving up a
degree of aerodynamic and pointing perfection for a larger area
lower down (lower heeling moment/area) and ease of rigging and
handling, and to boot it as a tree-trunk at the leading edge, the
sail was vertical seamed. (the authority for "I am told" was Ken
O'Brien). There are also supposed to be advantages in the event
of a tear, but I don't believe that.

Flying Tadpole's gaff sails and flying jib mit club were also
vertically cut, but her main staysail cross-cut.

Flying Tadpole

The navigator© wrote:



Hi Tim,

I just looked at the main panel layout on Lady K. and it struck me that
the main seams were not running as I expected. What's the story?

Cheers MC

Gaff sails?
 

But what about just head and mizz??? Wouldn't that maintain drive and
balance?

Cheers MC



Flying Tadpole wrote:
In those conditions and rigged with only the 3reef main, killing
it almost stone dead. Tthe 2.5mi were gained in 4 hours. I
perservered with the experiment to see what would happen. It
certainly would have clawed off a lee shore but...Hove to in
rougher conditions (no I wasn't then trying to sail uphill) two
years ago, leeward drift was about 1knot.

The grip on the water and the leeway with a balanced rig up
normally isn't bad, even in turbulent stuff: what was the real
killer was stubbing toes on the very short-period, square chop
coming from multiple directions (all vaguely windward). A
classical sharpie underwater hull shape lifts quite nicely to
windward, the leeward chine dug in, the boards down etc. But, a
homely transom bow will really cop it sweet in a very short
chop. I'll have to persuade Oz1 to come out on a bad day just to
see how strange the chop is (you'll never believe me otherwise).

No grip is any good, on a shoal draft boat, when the whole lake
blows bodily to leeward, which I have also seen (tho fortunately
was not out in it...). Cecil B de Mille and his Biblical
swimming pool has nothing on it.

FT

The navigator© wrote:

But it's the headsail that really drives to windward! What would have
happened under head and mizzen I wonder... While the deep reef main
would have helped sink her chine this might not help as much as one
would hope due to energy loss in the turbulence. Hmm an interesting
problem for which my trimming intuitions are ambivalent. Tack through 90
is fine but your leeway must be killing your VMG for such low figures
-right?

Cheers MC

Flying Tadpole wrote:

The navigator© wrote:


I didn't realize that 'uncle conor' would know a lot about cruising
sails for gaff rigged boats!


"Saorise", although a brigantine, did have fore-and-aft sails
too. What you _should_ have queried was how old my sailmaker was
when his uncle was alive...



But in any case, can 90 degrees to the wind
be called going to windward? When one factors leeway, wouldn't you
always end up in a Jackass port? Weatherliness is close to Godliness!


Cruel of you to play in my indolent language in such a way, MC.
"Tacking through x degrees" was the intended implication, not "x
degrees to the wind". But you knew that.

I tried out the minimum 3 reef main with no mizzen in the
near-gale and chop of the other weekend. A mess. Lee helm and
all. 2.5mi gain in about 18mi on the map (two beats). With the
mizzen back in operation, not too bad at all, though I should
have let her foot a little more. I think I reported it last week
for the ng's edification, but it got lost in the subsequent DTs.

Flying Tadpole


Cheers MC

Flying Tadpole wrote:


Well, MC, I agree with all you say, as it was also what I
thought. However, in the case of Flying Tadpole II (Lady Kate
already had her suit) I took the advice of the sailmaker instead,
possibly because, as the sailmaker responsible for breaking the
hearts of the NYYC I felt he might know more than I, or possibly
because he learnt a few things from his uncle Conor that I
mightn't know in relation to cruising sails.

Mind you, I normally refuse to bow to authority unless it's
approaching celestial, but in this case I did not feel my own
experience and thoughts were defensible...

BTW, you appear to be still defining "efficiency" purely in terms
of extracting the maximum degree of weatherliness (70 degrees?).
Being naturally indolent, I tend to regard an efficient rig as
one which limits the demands on crew, machinery, rigging and
hull, while still providing a good degree of weatherliness (90
degrees).

Flying Tadpole

The navigator© wrote:



Yes, I was expecting cross cut as you are using Dacron. BUT seaming is
still very important... e.g.

http://woodsdesignssailingcatamarans.com/rigs.htm

" In the old days of cotton gaff sails the cloth was weak and thus seams
ran vertically so, if they tore, the sail would not break in half. With
the advent of Dacron/Terylene, cross cut sails came into vogue partly
because these were (and still are) cheap to produce. More recently
computer sail design packages and laser cutters have made it easy for
sail lofts to make sails with more exotic panel layouts. "

Nevertheless i would have thought that with an inefficient rig, sail
shape would be even more critical and twist/draft control very
important. Even though Lady Kate would go very well downwind with any
(or even no) sail don't you want a bit more going to wind -or are all
your ports downwind...

Cheers MC

Flying Tadpole wrote:



Either:

can you be more specific? Which photo, what were you expecting?

Or:

If referring to "vertical" seams: Vertical of course was
traditional, until cross-cut demonstrated its superiority in the
old fabrics. With dacron, I am told that unless one is seeking
the absolutely last iota of aerodynamic efficiency, the direction
of the seaming makes almost no difference at all with modern
materials, modern seaming and heavy cloth (which Lady Kates main
certainly is!). As it's a gaff sail, and one is giving up a
degree of aerodynamic and pointing perfection for a larger area
lower down (lower heeling moment/area) and ease of rigging and
handling, and to boot it as a tree-trunk at the leading edge, the
sail was vertical seamed. (the authority for "I am told" was Ken
O'Brien). There are also supposed to be advantages in the event
of a tear, but I don't believe that.

Flying Tadpole's gaff sails and flying jib mit club were also
vertically cut, but her main staysail cross-cut.

Flying Tadpole

The navigator© wrote:




Hi Tim,

I just looked at the main panel layout on Lady K. and it struck me that
the main seams were not running as I expected. What's the story?

Cheers MC