With a mast-head sloop rig all the positioning and rake of a mast is done with its fore-and-aft stays. With the WWP19's fractional rig the backstay is actually an option, and so rake is traditionally done with the shrouds, which have a small amount of drift aft of the mast. This positions not the mast head, but the fractional point where the shrouds and forestay attach.

If you use the shrouds and forestay to position that point with a bit of rake, the mast forms a curve below the fractional attachment point, and the upper portion an uncurved flat line. This is not bad! but it is not as good as it could be if the length of the curve were longer. The curve itself absorbs load differently than the straight portion, because it is a tensioned spring while the upper section does not absorb load until tensioned. The two shrouds and the forestay transmit all transverse and aft forces, and the backstay does not begin to transmit forces until the masthead bends away from the load - usually as the wind approaches abeam or is abaft the beam.

By using the forestay and the backstay to position the masthead, and the shrouds solely to control the centring of the mast, you reduce the over-all load on any one wire in the rig. Because the backstay is much further aft than the shrouds, and attaches at the mast head, it requires less force to overcome the mast's own resistance to bending. It also moves the curve up, because it is positioning the masthead, not the fractional point of attachment, so the curve is over the entire length of the mast.

(There are a lot more dynamics involved, like how shrouds and stays alter the shape of the hull and how that can be modified on-the-fly for sea state, etc., but trying to keep this focused on the backstay.)

That does not mean you cannot be ham-handed and up with an unfair curve. But it does make it easier to put in a fair curve, which spreads force more evenly down into the hull with lower point loads, which ultimately means you should break things less often than you otherwise would.

That's a lot more technical than real, in discussion. A WWP19 may sail its entire life with no visible difference with how the rig is tensioned. But if you look at the boats winning races you will see a difference. Efficient rigs sail faster. (But... racing boats push their limits more, and break more gear. So maybe the whole discussion is without any point.)

Amgine

Thanks.  I love the technical points.  I’m going to have to read this a few times to digest. 

 

And, I do have a backstay.  I am proud that I installed it myself last summer.

 

My previous understanding was that the aft rake should be “dialed in” by the upper shrouds, and that the backstay is supposed to support the rake when the mast is under load.

 

From: wwpotter@groups.io <wwpotter@groups.io> On Behalf Of Amgine
Sent: Wednesday, April 13, 2022 3:49 PM
To: wwpotter@groups.io
Subject: Re: [wwpotter] Possible shroud replacement

 

I'm here all week! :badum-tish:

One quick note I forgot to ask about: do you have the backstay rigged?

If you do, slack up on the upper stays a few turns, and take up on the forestay. This will pull the upper half of the mast slightly forward. Remember to slack off your back stay or raising is going to be a bit of a pain.

Now, get the masthead centred again, and use the backstay to pull in the desired rake. Double check your masthead is centred again - it will probably be a smidge off to stbd.

What this does: because your mast is now slightly bowed (and it is *very* slight, though it will be more when the wind pipes up) the upper two-thirds of your sail when hoisted will be a little bit flatter, geometrically, than the lower third. This is good because of the maths of sail shape: the upper portion, being further up the lever that is your mast, produces more heeling force from every ounce of force it develops from the wind, AND because it is higher up the mast it is also experiencing slightly faster wind, which needs a slightly flatter shape to be as efficient as the lower portion. This helps 'balance' the sail top to bottom.

I will be honest and say I do not do this. It is too much fiddling at the dock when I could be sailing - however inefficiently. Sometimes, when out for a bit of a trip, I will do it. Usually after someone sailed away from me with whom I thought I should have been able to keep up. (Blame the boat! not the sailor!) But it is performance tweaking, not essential.

Amgine

 

On 13/04/2022 12:10, earons@... wrote:

Amgine:

 

Amazing, as always!

 

Thanks!

 

Ted

 

From: wwpotter@groups.io <wwpotter@groups.io> On Behalf Of Amgine
Sent: Wednesday, April 13, 2022 3:03 PM
To: wwpotter@groups.io
Subject: Re: [wwpotter] Possible shroud replacement

 

Stainless cable does stretch as it settles in to its new shape (no longer rolled on a drum), and different manufacturers stretch different amounts, as does the first cables from a spool versus the last ones. Getting it 'just right' is part art, part luck, part science.

And then there are those mast raisings... tangs bent side ways, bad decisions during raising… things can get too much force applied here and there.

Most likely your boat's rigging is suffering from a combination of slight miscalculations in building the rig, its age, the close engineering of a lightly built craft, and the unusual strains of a rig raised and lowered often in sometimes adverse conditions. It is even possible the fibreglass under the compression post has deformed a little bit over time, 'shortening' the mast a bit. The net changes over 25+ years result in what you are seeing.

Making up new shrouds is not difficult, but keeping in mind that these are kinda essential you may want to talk over your options with a local rigger. The emphasis is on local, really really close to where you sail, and hopefully someone you can invite out for a lunch break at a taco shop - $25 bucks on fast food (or nicer?) may help out a lot in the long run. They may have some great ideas for you to do it yourself, or maybe get interested in the project and set up a complete mast-raising kit for you. You never know until you ask. And of course they will need to see and measure the actual boat.

This is a small boat. You may want to spend some $$ and time experimenting. Maybe try to splice together some dyneema, with a ring as a dead-eye. Might be a chance to explore swageless mechanical fittings. Most DIY projects will actually cost more than having a pro do it, because you are learning/do not have all the tools (yet)/bought the wrong part/etc. But, this is a small boat. Maybe you will be moving up, so it is cheaper to learn here before moving there.

And, you will be pottering about with your boat!

Amgine

 

On 13/04/2022 11:04, earons@... wrote:

Looking for opinions:

 

Last seasone, I tuned my 1997 P’19 shrouds and mast following Judy B’s guidelines.  When I got the mast centered beam-to-beam and raked backward a few inches, the upper-shroud turnbuckles bottomed out.  (Couldn’t shorten them further.)  I’d like to get a little more rake, so I’m thinking about having some new shrouds made up—a little shorter than what I have.  Does anyone have any wisdom to bring to bear on this situation?  Can shrouds can stretch over time?  The thimbles that go through the tangs on the mast appear to be deformed (stretched out), but it’s hard to imagine that such deformation would provide enough slack to cause the turnbuckles to bottom out.

 

I’m all ears.

 

Thanks.

 

Ted

 

Thanks.  I love the technical points.  I’m going to have to read this a few times to digest. 

 

And, I do have a backstay.  I am proud that I installed it myself last summer.

 

My previous understanding was that the aft rake should be “dialed in” by the upper shrouds, and that the backstay is supposed to support the rake when the mast is under load.

 

From: wwpotter@groups.io <wwpotter@groups.io> On Behalf Of Amgine
Sent: Wednesday, April 13, 2022 3:49 PM
To: wwpotter@groups.io
Subject: Re: [wwpotter] Possible shroud replacement

 

I'm here all week! :badum-tish:

One quick note I forgot to ask about: do you have the backstay rigged?

If you do, slack up on the upper stays a few turns, and take up on the forestay. This will pull the upper half of the mast slightly forward. Remember to slack off your back stay or raising is going to be a bit of a pain.

Now, get the masthead centred again, and use the backstay to pull in the desired rake. Double check your masthead is centred again - it will probably be a smidge off to stbd.

What this does: because your mast is now slightly bowed (and it is *very* slight, though it will be more when the wind pipes up) the upper two-thirds of your sail when hoisted will be a little bit flatter, geometrically, than the lower third. This is good because of the maths of sail shape: the upper portion, being further up the lever that is your mast, produces more heeling force from every ounce of force it develops from the wind, AND because it is higher up the mast it is also experiencing slightly faster wind, which needs a slightly flatter shape to be as efficient as the lower portion. This helps 'balance' the sail top to bottom.

I will be honest and say I do not do this. It is too much fiddling at the dock when I could be sailing - however inefficiently. Sometimes, when out for a bit of a trip, I will do it. Usually after someone sailed away from me with whom I thought I should have been able to keep up. (Blame the boat! not the sailor!) But it is performance tweaking, not essential.

Amgine

 

On 13/04/2022 12:10, earons@... wrote:

Amgine:

 

Amazing, as always!

 

Thanks!

 

Ted

 

From: wwpotter@groups.io <wwpotter@groups.io> On Behalf Of Amgine
Sent: Wednesday, April 13, 2022 3:03 PM
To: wwpotter@groups.io
Subject: Re: [wwpotter] Possible shroud replacement

 

Stainless cable does stretch as it settles in to its new shape (no longer rolled on a drum), and different manufacturers stretch different amounts, as does the first cables from a spool versus the last ones. Getting it 'just right' is part art, part luck, part science.

And then there are those mast raisings... tangs bent side ways, bad decisions during raising… things can get too much force applied here and there.

Most likely your boat's rigging is suffering from a combination of slight miscalculations in building the rig, its age, the close engineering of a lightly built craft, and the unusual strains of a rig raised and lowered often in sometimes adverse conditions. It is even possible the fibreglass under the compression post has deformed a little bit over time, 'shortening' the mast a bit. The net changes over 25+ years result in what you are seeing.

Making up new shrouds is not difficult, but keeping in mind that these are kinda essential you may want to talk over your options with a local rigger. The emphasis is on local, really really close to where you sail, and hopefully someone you can invite out for a lunch break at a taco shop - $25 bucks on fast food (or nicer?) may help out a lot in the long run. They may have some great ideas for you to do it yourself, or maybe get interested in the project and set up a complete mast-raising kit for you. You never know until you ask. And of course they will need to see and measure the actual boat.

This is a small boat. You may want to spend some $$ and time experimenting. Maybe try to splice together some dyneema, with a ring as a dead-eye. Might be a chance to explore swageless mechanical fittings. Most DIY projects will actually cost more than having a pro do it, because you are learning/do not have all the tools (yet)/bought the wrong part/etc. But, this is a small boat. Maybe you will be moving up, so it is cheaper to learn here before moving there.

And, you will be pottering about with your boat!

Amgine

 

On 13/04/2022 11:04, earons@... wrote:

Looking for opinions:

 

Last seasone, I tuned my 1997 P’19 shrouds and mast following Judy B’s guidelines.  When I got the mast centered beam-to-beam and raked backward a few inches, the upper-shroud turnbuckles bottomed out.  (Couldn’t shorten them further.)  I’d like to get a little more rake, so I’m thinking about having some new shrouds made up—a little shorter than what I have.  Does anyone have any wisdom to bring to bear on this situation?  Can shrouds can stretch over time?  The thimbles that go through the tangs on the mast appear to be deformed (stretched out), but it’s hard to imagine that such deformation would provide enough slack to cause the turnbuckles to bottom out.

 

I’m all ears.

 

Thanks.

 

Ted

 

I'm here all week! :badum-tish:

One quick note I forgot to ask about: do you have the backstay rigged?

If you do, slack up on the upper stays a few turns, and take up on the forestay. This will pull the upper half of the mast slightly forward. Remember to slack off your back stay or raising is going to be a bit of a pain.

Now, get the masthead centred again, and use the backstay to pull in the desired rake. Double check your masthead is centred again - it will probably be a smidge off to stbd.

What this does: because your mast is now slightly bowed (and it is *very* slight, though it will be more when the wind pipes up) the upper two-thirds of your sail when hoisted will be a little bit flatter, geometrically, than the lower third. This is good because of the maths of sail shape: the upper portion, being further up the lever that is your mast, produces more heeling force from every ounce of force it develops from the wind, AND because it is higher up the mast it is also experiencing slightly faster wind, which needs a slightly flatter shape to be as efficient as the lower portion. This helps 'balance' the sail top to bottom.

I will be honest and say I do not do this. It is too much fiddling at the dock when I could be sailing - however inefficiently. Sometimes, when out for a bit of a trip, I will do it. Usually after someone sailed away from me with whom I thought I should have been able to keep up. (Blame the boat! not the sailor!) But it is performance tweaking, not essential.

Amgine

Amgine:

 

Amazing, as always!

 

Thanks!

 

Ted

 

From: wwpotter@groups.io <wwpotter@groups.io> On Behalf Of Amgine
Sent: Wednesday, April 13, 2022 3:03 PM
To: wwpotter@groups.io
Subject: Re: [wwpotter] Possible shroud replacement

 

Stainless cable does stretch as it settles in to its new shape (no longer rolled on a drum), and different manufacturers stretch different amounts, as does the first cables from a spool versus the last ones. Getting it 'just right' is part art, part luck, part science.

And then there are those mast raisings... tangs bent side ways, bad decisions during raising… things can get too much force applied here and there.

Most likely your boat's rigging is suffering from a combination of slight miscalculations in building the rig, its age, the close engineering of a lightly built craft, and the unusual strains of a rig raised and lowered often in sometimes adverse conditions. It is even possible the fibreglass under the compression post has deformed a little bit over time, 'shortening' the mast a bit. The net changes over 25+ years result in what you are seeing.

Making up new shrouds is not difficult, but keeping in mind that these are kinda essential you may want to talk over your options with a local rigger. The emphasis is on local, really really close to where you sail, and hopefully someone you can invite out for a lunch break at a taco shop - $25 bucks on fast food (or nicer?) may help out a lot in the long run. They may have some great ideas for you to do it yourself, or maybe get interested in the project and set up a complete mast-raising kit for you. You never know until you ask. And of course they will need to see and measure the actual boat.

This is a small boat. You may want to spend some $$ and time experimenting. Maybe try to splice together some dyneema, with a ring as a dead-eye. Might be a chance to explore swageless mechanical fittings. Most DIY projects will actually cost more than having a pro do it, because you are learning/do not have all the tools (yet)/bought the wrong part/etc. But, this is a small boat. Maybe you will be moving up, so it is cheaper to learn here before moving there.

And, you will be pottering about with your boat!

Amgine

 

On 13/04/2022 11:04, earons@... wrote:

Looking for opinions:

 

Last seasone, I tuned my 1997 P’19 shrouds and mast following Judy B’s guidelines.  When I got the mast centered beam-to-beam and raked backward a few inches, the upper-shroud turnbuckles bottomed out.  (Couldn’t shorten them further.)  I’d like to get a little more rake, so I’m thinking about having some new shrouds made up—a little shorter than what I have.  Does anyone have any wisdom to bring to bear on this situation?  Can shrouds can stretch over time?  The thimbles that go through the tangs on the mast appear to be deformed (stretched out), but it’s hard to imagine that such deformation would provide enough slack to cause the turnbuckles to bottom out.

 

I’m all ears.

 

Thanks.

 

Ted

 

My shrouds came from the factory in 2008 adjusted like yours are right now.  The mast was always leaning to the rear a few inches.  The turnbuckles were also maxed out.  I put up with it for 10 years because all it did was cause a little weather helm, which I didn't mind.  When it bothered me was when I added a bimini.  The boom was hitting the bimini.  So, I finally needed to make the mast vertical.  I thought I was going to have to order new shrouds but then I got the great idea to just drill new anchor holes for the shrouds at the top of the mast.  I think I wound up putting the new holes a few inches below the old ones.  With adjustments all the turnbuckles have plenty of play for tuning.  The mast is now vertical, the bimini is installed with plenty of clearance under the boom.  Shrouds work great.  Life is good, haha.

Amgine:

 

Amazing, as always!

 

Thanks!

 

Ted

 

From: wwpotter@groups.io <wwpotter@groups.io> On Behalf Of Amgine
Sent: Wednesday, April 13, 2022 3:03 PM
To: wwpotter@groups.io
Subject: Re: [wwpotter] Possible shroud replacement

 

Stainless cable does stretch as it settles in to its new shape (no longer rolled on a drum), and different manufacturers stretch different amounts, as does the first cables from a spool versus the last ones. Getting it 'just right' is part art, part luck, part science.

And then there are those mast raisings... tangs bent side ways, bad decisions during raising… things can get too much force applied here and there.

Most likely your boat's rigging is suffering from a combination of slight miscalculations in building the rig, its age, the close engineering of a lightly built craft, and the unusual strains of a rig raised and lowered often in sometimes adverse conditions. It is even possible the fibreglass under the compression post has deformed a little bit over time, 'shortening' the mast a bit. The net changes over 25+ years result in what you are seeing.

Making up new shrouds is not difficult, but keeping in mind that these are kinda essential you may want to talk over your options with a local rigger. The emphasis is on local, really really close to where you sail, and hopefully someone you can invite out for a lunch break at a taco shop - $25 bucks on fast food (or nicer?) may help out a lot in the long run. They may have some great ideas for you to do it yourself, or maybe get interested in the project and set up a complete mast-raising kit for you. You never know until you ask. And of course they will need to see and measure the actual boat.

This is a small boat. You may want to spend some $$ and time experimenting. Maybe try to splice together some dyneema, with a ring as a dead-eye. Might be a chance to explore swageless mechanical fittings. Most DIY projects will actually cost more than having a pro do it, because you are learning/do not have all the tools (yet)/bought the wrong part/etc. But, this is a small boat. Maybe you will be moving up, so it is cheaper to learn here before moving there.

And, you will be pottering about with your boat!

Amgine

 

On 13/04/2022 11:04, earons@... wrote:

Looking for opinions:

 

Last seasone, I tuned my 1997 P’19 shrouds and mast following Judy B’s guidelines.  When I got the mast centered beam-to-beam and raked backward a few inches, the upper-shroud turnbuckles bottomed out.  (Couldn’t shorten them further.)  I’d like to get a little more rake, so I’m thinking about having some new shrouds made up—a little shorter than what I have.  Does anyone have any wisdom to bring to bear on this situation?  Can shrouds can stretch over time?  The thimbles that go through the tangs on the mast appear to be deformed (stretched out), but it’s hard to imagine that such deformation would provide enough slack to cause the turnbuckles to bottom out.

 

I’m all ears.

 

Thanks.

 

Ted

 

Stainless cable does stretch as it settles in to its new shape (no longer rolled on a drum), and different manufacturers stretch different amounts, as does the first cables from a spool versus the last ones. Getting it 'just right' is part art, part luck, part science.

And then there are those mast raisings... tangs bent side ways, bad decisions during raising… things can get too much force applied here and there.

Most likely your boat's rigging is suffering from a combination of slight miscalculations in building the rig, its age, the close engineering of a lightly built craft, and the unusual strains of a rig raised and lowered often in sometimes adverse conditions. It is even possible the fibreglass under the compression post has deformed a little bit over time, 'shortening' the mast a bit. The net changes over 25+ years result in what you are seeing.

Making up new shrouds is not difficult, but keeping in mind that these are kinda essential you may want to talk over your options with a local rigger. The emphasis is on local, really really close to where you sail, and hopefully someone you can invite out for a lunch break at a taco shop - $25 bucks on fast food (or nicer?) may help out a lot in the long run. They may have some great ideas for you to do it yourself, or maybe get interested in the project and set up a complete mast-raising kit for you. You never know until you ask. And of course they will need to see and measure the actual boat.

This is a small boat. You may want to spend some $$ and time experimenting. Maybe try to splice together some dyneema, with a ring as a dead-eye. Might be a chance to explore swageless mechanical fittings. Most DIY projects will actually cost more than having a pro do it, because you are learning/do not have all the tools (yet)/bought the wrong part/etc. But, this is a small boat. Maybe you will be moving up, so it is cheaper to learn here before moving there.

And, you will be pottering about with your boat!

Amgine

Looking for opinions:

 

Last seasone, I tuned my 1997 P’19 shrouds and mast following Judy B’s guidelines.  When I got the mast centered beam-to-beam and raked backward a few inches, the upper-shroud turnbuckles bottomed out.  (Couldn’t shorten them further.)  I’d like to get a little more rake, so I’m thinking about having some new shrouds made up—a little shorter than what I have.  Does anyone have any wisdom to bring to bear on this situation?  Can shrouds can stretch over time?  The thimbles that go through the tangs on the mast appear to be deformed (stretched out), but it’s hard to imagine that such deformation would provide enough slack to cause the turnbuckles to bottom out.

 

I’m all ears.

 

Thanks.

 

Ted

 

Looking for opinions:

 

Last seasone, I tuned my 1997 P’19 shrouds and mast following Judy B’s guidelines.  When I got the mast centered beam-to-beam and raked backward a few inches, the upper-shroud turnbuckles bottomed out.  (Couldn’t shorten them further.)  I’d like to get a little more rake, so I’m thinking about having some new shrouds made up—a little shorter than what I have.  Does anyone have any wisdom to bring to bear on this situation?  Can shrouds can stretch over time?  The thimbles that go through the tangs on the mast appear to be deformed (stretched out), but it’s hard to imagine that such deformation would provide enough slack to cause the turnbuckles to bottom out.

 

I’m all ears.

 

Thanks.

 

Ted