Re: [bolger] Re: Chinese Gaffer - Proa - Time to Junk that Xmas Tree
On 03/27/2011 11:30 AM, Douglas Pollard wrote:
material.
Doug
> The junk and the square rigger had this in common.Sorry that is not correct the square rigger needed very strong sail
material.
Doug
Well we agree, in that yes the western rig with its air foil is
a faster rig to windward that is pretty obvious. The junk rig has a
purpose and advantages, the square rig has a purpose and advantages
and the for and aft Bermuda rig both Burmuda and free standing have
advantages.
I was born in 1934 and grew up with neighbours that had been square rig sailors on clipper ships. What only a very few knows today is that the square rig sailed very tight to windward. It was the hulls that could not. Square riggers did not have any twist in the sail as our modern rigs do. The sails were hauled around to windward and the aft end of the top and bottom yards were hauled in and down tight. This tightened the luff of the sail. Because the top and bottom of the sail were in tight and there was no twist. The ship could point about 40 degrees to windward and often did. They made hells of leeway. This idea that square riggers couldn't sail to windward is false. What they couldn't do to windward was to carry much sail. They would turn turtle.
The junk rig was intended to sail a junk not a western hull. Many junks were narrow so they had High hull speeds. This was possible because the rig also did not have to be hauled in tight as there was not twist in the sail also. We should not confuse hauling sails in tight with going tight to windward they are different things altogether.
A couple I knew built a Gazelle and they used Sunbrella to make sails out of compared to Dacron it is very weak material. The Gazzelle had a jib, a mistake by my thinking. The jib kept blowing out and they replaced it with a Dacron sail. They sailed the entire carribean with a dacron jib and those weak sunbrella sails and had no problem. If you look at the sails of eastern junks they are hanging in tatters but continue to work. The junk and the square rigger had this in common.
We in the west are sailing ballasted or wide boats that can carry sail hard on the wind. Very high hull stability is needed for these rigs. Then there is Bolgers sprite rig that can sail hard on the wind with the sail also far off the rail. Here again there is no twist. Like the junk it can carry a free standing mast. The Bermuda rig needs very expensive rigging to haul the sails tight to windward. IT also needs a boomvang to sail with the twist pulled out of the sail and that puts a load on the rigging.
The junk rig doesn't even need any cloth in the sail to sail well. The sail could be all flat battens laced together and it would sail just as well as it will with cloth. It would be heavy so the battens are spread out with cloth in between. Still the battens carry 90% of the load the closer the battens are together the weaker the sail cloth can be.
A sail like an airplane wing can only create lift between about 7 deg, and 18deg. to windward. This means the bottom of a Bermuda rig does not pull at all. Only the top that has swung out to 17deg. off the wind is pulling. They had to invent the boom vang to overcome this problem.
As I see it, the advantage of the junk is that there is almost no load on any large area of sail. There is little healing moment so hulls can be narrow and fast as well as more seaworthy. A long narrow hull is very sea worthy.
With almost no load on the sail cloth a mainsail can be made from the biggest piece of canvas you can find as close sewn seams are not required to carry the load. A polytarp is just fine and you can use it to go off to sea of course the battens may need to be a little closer. The good news is mildew will not kill the polytarp though sunlight will. Carry along a few extra tarps for sail replacement though you can buy extra any place in the world you go.
The above is the real advantage of the junk rig. Oh the self reefing is not to be sneezed at.
I think there are a lot of adavantges to a Junk rig and the biggest one is cost. The sails are cheap, the hull is cheap, and the rigging is cheap and standing rigging nonexistant. I just don't understand why anyone would want to make all this cost more for a very small imagined advantage.
When you first think of building a boat plant some bamboo in the back yard and you won't even have to buy battens.
Mac Naugtons Sivergull is a perfect combination of low stability high seaworthy dory hull combination. A cheap boat a cheap rig and a go any place you want, combination. Bolger has a lot of boats that are perfect for a junk rig as may were designed for a sprite rig.
BY the way nobody but God and I pilot my boats, but I do listen to some who know something of value.
I understand what you are saying and you are right, we just disagree because we are looking at this from a different point of view.
Doug
I was born in 1934 and grew up with neighbours that had been square rig sailors on clipper ships. What only a very few knows today is that the square rig sailed very tight to windward. It was the hulls that could not. Square riggers did not have any twist in the sail as our modern rigs do. The sails were hauled around to windward and the aft end of the top and bottom yards were hauled in and down tight. This tightened the luff of the sail. Because the top and bottom of the sail were in tight and there was no twist. The ship could point about 40 degrees to windward and often did. They made hells of leeway. This idea that square riggers couldn't sail to windward is false. What they couldn't do to windward was to carry much sail. They would turn turtle.
The junk rig was intended to sail a junk not a western hull. Many junks were narrow so they had High hull speeds. This was possible because the rig also did not have to be hauled in tight as there was not twist in the sail also. We should not confuse hauling sails in tight with going tight to windward they are different things altogether.
A couple I knew built a Gazelle and they used Sunbrella to make sails out of compared to Dacron it is very weak material. The Gazzelle had a jib, a mistake by my thinking. The jib kept blowing out and they replaced it with a Dacron sail. They sailed the entire carribean with a dacron jib and those weak sunbrella sails and had no problem. If you look at the sails of eastern junks they are hanging in tatters but continue to work. The junk and the square rigger had this in common.
We in the west are sailing ballasted or wide boats that can carry sail hard on the wind. Very high hull stability is needed for these rigs. Then there is Bolgers sprite rig that can sail hard on the wind with the sail also far off the rail. Here again there is no twist. Like the junk it can carry a free standing mast. The Bermuda rig needs very expensive rigging to haul the sails tight to windward. IT also needs a boomvang to sail with the twist pulled out of the sail and that puts a load on the rigging.
The junk rig doesn't even need any cloth in the sail to sail well. The sail could be all flat battens laced together and it would sail just as well as it will with cloth. It would be heavy so the battens are spread out with cloth in between. Still the battens carry 90% of the load the closer the battens are together the weaker the sail cloth can be.
A sail like an airplane wing can only create lift between about 7 deg, and 18deg. to windward. This means the bottom of a Bermuda rig does not pull at all. Only the top that has swung out to 17deg. off the wind is pulling. They had to invent the boom vang to overcome this problem.
As I see it, the advantage of the junk is that there is almost no load on any large area of sail. There is little healing moment so hulls can be narrow and fast as well as more seaworthy. A long narrow hull is very sea worthy.
With almost no load on the sail cloth a mainsail can be made from the biggest piece of canvas you can find as close sewn seams are not required to carry the load. A polytarp is just fine and you can use it to go off to sea of course the battens may need to be a little closer. The good news is mildew will not kill the polytarp though sunlight will. Carry along a few extra tarps for sail replacement though you can buy extra any place in the world you go.
The above is the real advantage of the junk rig. Oh the self reefing is not to be sneezed at.
I think there are a lot of adavantges to a Junk rig and the biggest one is cost. The sails are cheap, the hull is cheap, and the rigging is cheap and standing rigging nonexistant. I just don't understand why anyone would want to make all this cost more for a very small imagined advantage.
When you first think of building a boat plant some bamboo in the back yard and you won't even have to buy battens.
Mac Naugtons Sivergull is a perfect combination of low stability high seaworthy dory hull combination. A cheap boat a cheap rig and a go any place you want, combination. Bolger has a lot of boats that are perfect for a junk rig as may were designed for a sprite rig.
BY the way nobody but God and I pilot my boats, but I do listen to some who know something of value.
I understand what you are saying and you are right, we just disagree because we are looking at this from a different point of view.
Doug
On 03/27/2011 07:01 AM, c.ruzer wrote:
Doug, I appreciate your experience, and have noted the several points you made. (some here snipped)
At subsonic speeds cambered aerofoils perform better than plates. Drawing a flat cut junksail in too tight is real easy on the wind for there are only 2 or 3 degrees of angle of attack where it's at all effective lifting - the thing PCB didn't like particularly about the junk. Cambered foils have a larger range of attack before stalling so concentration when on the wind can be significantly less, in addition to that range being much closer to the wind. Cambered foils go to weather close hauled much better. The newer cambered junk sails acheive similar performance to a good bermudan on the wind - a cambered foil is a cambered foil. These cambered junks aren't for racing (but who knows), nevertheless what's wrong with having a junk sail that performs better to windward - more lift, less drag, closer angle? Real sailors might not sail to windward given a choice, but what if Colvin isn't piloting you one day...
--- Inbolger@yahoogroups.com, Douglas Pollard<dougpol1@...>wrote:
>SNIPPED
> I think things like adding shape to the luff of the Junk main is
> fixing something that doesn't need to be fixed. If your junk rig is not
> pulling to suit you it is likely that you are drawing it in too tight
> going to windward.. Top speed to windward is not the intent of a junk
> rig. It is primarily an ocean rig. In ocean conditions a good steady
> medium speed under any condition is the goal. Fits and starts are not of
> any value to the ocean sailor. A couple i met in the bahams who were
> sailing a Colvin Gazeel claimdthe boat saied at 4knots under any
> condition, light air or a gale. They claimed they out ran modern
> Bermuda rigs by sailing constantly at four knots. I have wondered if
> that is really so.
> My only concern with the junk rig is what happens if I get jammed
> up on a lee shore and need to beat hard on the wind to get off??
> Colvin says don't get on lee shores. Why do you want to go some place
> you don't want to be?
> I have almost no technical knowledge of sail design but do learn to
> understand the sails on the boats I sail.
>
> Doug
Doug, I appreciate your experience, and have noted the several points you made. (some here snipped)
At subsonic speeds cambered aerofoils perform better than plates. Drawing a flat cut junksail in too tight is real easy on the wind for there are only 2 or 3 degrees of angle of attack where it's at all effective lifting - the thing PCB didn't like particularly about the junk. Cambered foils have a larger range of attack before stalling so concentration when on the wind can be significantly less, in addition to that range being much closer to the wind. Cambered foils go to weather close hauled much better. The newer cambered junk sails acheive similar performance to a good bermudan on the wind - a cambered foil is a cambered foil. These cambered junks aren't for racing (but who knows), nevertheless what's wrong with having a junk sail that performs better to windward - more lift, less drag, closer angle? Real sailors might not sail to windward given a choice, but what if Colvin isn't piloting you one day...
At subsonic speeds cambered aerofoils perform better than plates. Drawing a flat cut junksail in too tight is real easy on the wind for there are only 2 or 3 degrees of angle of attack where it's at all effective lifting - the thing PCB didn't like particularly about the junk. Cambered foils have a larger range of attack before stalling so concentration when on the wind can be significantly less, in addition to that range being much closer to the wind. Cambered foils go to weather close hauled much better. The newer cambered junk sails acheive similar performance to a good bermudan on the wind - a cambered foil is a cambered foil. These cambered junks aren't for racing (but who knows), nevertheless what's wrong with having a junk sail that performs better to windward - more lift, less drag, closer angle? Real sailors might not sail to windward given a choice, but what if Colvin isn't piloting you one day...
--- Inbolger@yahoogroups.com, Douglas Pollard <dougpol1@...> wrote:
>SNIPPED
> I think things like adding shape to the luff of the Junk main is
> fixing something that doesn't need to be fixed. If your junk rig is not
> pulling to suit you it is likely that you are drawing it in too tight
> going to windward.. Top speed to windward is not the intent of a junk
> rig. It is primarily an ocean rig. In ocean conditions a good steady
> medium speed under any condition is the goal. Fits and starts are not of
> any value to the ocean sailor. A couple i met in the bahams who were
> sailing a Colvin Gazeel claimdthe boat saied at 4knots under any
> condition, light air or a gale. They claimed they out ran modern
> Bermuda rigs by sailing constantly at four knots. I have wondered if
> that is really so.
> My only concern with the junk rig is what happens if I get jammed
> up on a lee shore and need to beat hard on the wind to get off??
> Colvin says don't get on lee shores. Why do you want to go some place
> you don't want to be?
> I have almost no technical knowledge of sail design but do learn to
> understand the sails on the boats I sail.
>
> Doug
in very light conditions <2-5> knots I had my lunch eaten by a junk rigged steel gazelle. IT was so quiet that you could hear the squeaking of all the tiny little blocks. Changed my opinion of junk rigged boats.
mike
mike
--- Inbolger@yahoogroups.com, Douglas Pollard <dougpol1@...> wrote:
>
> I talked to Mr. Bolger some about Junk Rigs as compared to his
> favourite rig the sprit boom rig. I have some misgivings about having a
> designer who doesn't like a junk rig, design one for me. That is the
> reason I did put one on Wolftrap as it was my original intent. I wanted
> Bolger to design the boatbut not a junk rig. We also talked a little
> about gaff rigs. MY favorite rig was a gaff rig despite some misgivings
> where the boom lifting and jibeing when running off the wind is a concern.
> I had talked to Tom Colvin some who used Junk rigs on his Gazelle.
> His thinking was that the traditional Junk rig was perfect for the 50 ft
> boat that is sailed short handed. One of the things he found was that
> most people don't want such a boat. Though liking the idea of a junk rig
> what they really want is a boat for Sunday afternoon racing and they
> insisted on a jib, Genoa and maybe spinnaker as well. Jibs mostly back
> wind the main because a Junk sails with the main way off to leeward
> because it can. A jib has to be pulled in tight to windward. Because
> the junk main pulls at the top as well as the bottom it doesn't need to
> be hauled in tight. IF this is not understood than there is a need to
> read some, on Junk rigs, and sprite rigs as well. Understanding sprite
> rigs helps to understand junk rigs.
> The most efficient rig out there for a free standing mast is
> Bolgers sprit boom rig, It's faster than a junk and faster than a Gaff
> rig at least to windward and his rig and sharpy hull design will out
> sail any modern Bermuda rig I ever came up on and passed. The sprit rig
> is not prone to jibing because the sprite cannot lift allowing wind to
> get behind it.
> I have come to like the sprite rig with a top sprite and a bottom
> sprite boom. Like the Gaff rig you can scandalise it to shorten the rig
> in a hurry and then reef when conditions permit.
> I think things like adding shape to the luff of the Junk main is
> fixing something that doesn't need to be fixed. If your junk rig is not
> pulling to suit you it is likely that you are drawing it in too tight
> going to windward.. Top speed to windward is not the intent of a junk
> rig. It is primarily an ocean rig. In ocean conditions a good steady
> medium speed under any condition is the goal. Fits and starts are not of
> any value to the ocean sailor. A couple i met in the bahams who were
> sailing a Colvin Gazeel claimdthe boat saied at 4knots under any
> condition, light air or a gale. They claimed they out ran modern
> Bermuda rigs by sailing constantly at four knots. I have wondered if
> that is really so.
> My only concern with the junk rig is what happens if I get jammed
> up on a lee shore and need to beat hard on the wind to get off??
> Colvin says don't get on lee shores. Why do you want to go some place
> you don't want to be?
> I have almost no technical knowledge of sail design but do learn to
> understand the sails on the boats I sail.
>
> Doug
>
> On 03/22/2011 11:42 PM, c.ruzer wrote:
> >
> >
> >
> > --- Inbolger@yahoogroups.com<mailto:bolger%40yahoogroups.com>,
> > "c.ruzer" <c.ruzer@> wrote:
> > >
> > > Amongst other advantages common to the rethunk junk sail, a Xmas Tree
> > > rig with increasing camber shaped into the cloth of progressively
> > > higher panels
> >
> > Correction:
> >
> > Strike "increasing", insert "decreasing".
> >
> >
>
I had talked to Tom Colvin some who used Junk rigs on his Gazelle. His thinking was that the traditional Junk rig was perfect for the 50 ft boat that is sailed short handed. One of the things he found was that most people don't want such a boat. Though liking the idea of a junk rig what they really want is a boat for Sunday afternoon racing and they insisted on a jib, Genoa and maybe spinnaker as well. Jibs mostly back wind the main because a Junk sails with the main way off to leeward because it can. A jib has to be pulled in tight to windward. Because the junk main pulls at the top as well as the bottom it doesn't need to be hauled in tight. IF this is not understood than there is a need to read some, on Junk rigs, and sprite rigs as well. Understanding sprite rigs helps to understand junk rigs.
The most efficient rig out there for a free standing mast is Bolgers sprit boom rig, It's faster than a junk and faster than a Gaff rig at least to windward and his rig and sharpy hull design will out sail any modern Bermuda rig I ever came up on and passed. The sprit rig is not prone to jibing because the sprite cannot lift allowing wind to get behind it.
I have come to like the sprite rig with a top sprite and a bottom sprite boom. Like the Gaff rig you can scandalise it to shorten the rig in a hurry and then reef when conditions permit.
I think things like adding shape to the luff of the Junk main is fixing something that doesn't need to be fixed. If your junk rig is not pulling to suit you it is likely that you are drawing it in too tight going to windward.. Top speed to windward is not the intent of a junk rig. It is primarily an ocean rig. In ocean conditions a good steady medium speed under any condition is the goal. Fits and starts are not of any value to the ocean sailor. A couple i met in the bahams who were sailing a Colvin Gazeel claimdthe boat saied at 4knots under any condition, light air or a gale. They claimed they out ran modern Bermuda rigs by sailing constantly at four knots. I have wondered if that is really so.
My only concern with the junk rig is what happens if I get jammed up on a lee shore and need to beat hard on the wind to get off?? Colvin says don't get on lee shores. Why do you want to go some place you don't want to be?
I have almost no technical knowledge of sail design but do learn to understand the sails on the boats I sail.
Doug
On 03/22/2011 11:42 PM, c.ruzer wrote:
--- Inbolger@yahoogroups.com, "c.ruzer"<c.ruzer@...>wrote:
>
> Amongst other advantages common to the rethunk junk sail, a Xmas Tree
> rig with increasing camber shaped into the cloth of progressively
> higher panels
Correction:
Strike "increasing", insert "decreasing".
--- Inbolger@yahoogroups.com, "c.ruzer" <c.ruzer@...> wrote:
Strike "increasing", insert "decreasing".
>Correction:
> Amongst other advantages common to the rethunk junk sail, a Xmas Tree
> rig with increasing camber shaped into the cloth of progressively
> higher panels
Strike "increasing", insert "decreasing".
...A Ha! Xmas Tree Proa Sail
The CG discussion has caused a penny to drop coincidental to some current proa_file group discussion about the 20ft Minimum Proa shunting outrigger hull shape vs more typical Polynesian Wa'apa hull shapes, and coincidental to the continuing trials by Gary Dierking of the rethunk junk as applied to tacking outriggershttp://outriggersailingcanoes.blogspot.com/2010/10/more-junk-rig-tests.html
From hull shape to sail shape, and: WHY NOT apply the rethunk junk ideas to the AYRS (Bolger Christmas Tree proa rig) sail?!!
One main disadvantage, and dangerous too, of the AYRS sail is that for all intents and purposes it will not de-power, it will not luff either, as the battens maintain the camber present always. Now, were each panel to have camber sewn in by one of the rethunk junk sail making approaches instead of having it permanently induced by bowed battens, then the Xmas Tree sail should reliably luff. The ability to depower and luff a practical boat sail is a real necessity.
Amongst other advantages common to the rethunk junk sail, a Xmas Tree rig with increasing camber shaped into the cloth of progressively higher panels could not only be depowered by releasing the sheet: it could easily be reefed under control; the battens, boom, and a yard could be stiff, strong, and straight; the sail cloth would have to bear only a tiny tiny amount of stress; etc. Maximum camber would remain sewn in at the chord midpoint thus maintaining Bolger's original 20ft Minimum Proa application idea for instant proa shunting reversal of clew and tack.
The observed problematic issues arising from the tack to head pivot line shifting aft of the notional AYRS/Bolger sail plan pivot line may remain, but if so they should be diminished. At the least, they wouldn't continue to add to the observed AYRS dangers as the sail could be depowered instantly!
The CG discussion has caused a penny to drop coincidental to some current proa_file group discussion about the 20ft Minimum Proa shunting outrigger hull shape vs more typical Polynesian Wa'apa hull shapes, and coincidental to the continuing trials by Gary Dierking of the rethunk junk as applied to tacking outriggershttp://outriggersailingcanoes.blogspot.com/2010/10/more-junk-rig-tests.html
From hull shape to sail shape, and: WHY NOT apply the rethunk junk ideas to the AYRS (Bolger Christmas Tree proa rig) sail?!!
One main disadvantage, and dangerous too, of the AYRS sail is that for all intents and purposes it will not de-power, it will not luff either, as the battens maintain the camber present always. Now, were each panel to have camber sewn in by one of the rethunk junk sail making approaches instead of having it permanently induced by bowed battens, then the Xmas Tree sail should reliably luff. The ability to depower and luff a practical boat sail is a real necessity.
Amongst other advantages common to the rethunk junk sail, a Xmas Tree rig with increasing camber shaped into the cloth of progressively higher panels could not only be depowered by releasing the sheet: it could easily be reefed under control; the battens, boom, and a yard could be stiff, strong, and straight; the sail cloth would have to bear only a tiny tiny amount of stress; etc. Maximum camber would remain sewn in at the chord midpoint thus maintaining Bolger's original 20ft Minimum Proa application idea for instant proa shunting reversal of clew and tack.
The observed problematic issues arising from the tack to head pivot line shifting aft of the notional AYRS/Bolger sail plan pivot line may remain, but if so they should be diminished. At the least, they wouldn't continue to add to the observed AYRS dangers as the sail could be depowered instantly!