Steadying sail design/rigging?

[SteveK]

Deploying when the boat is rocking and rolling is not fun. Seldom does a sailboat motor into a wind and then set sails. Sailboats have the gear in place. Anyway, I ruled out a steady sail when had had the GB with mast and boom.

 

[LeoKa]

This is ours in use. If you are anywhere in the Puget Sound area, the Sailboat Wrecking Yard in Lynden, WA is a great source for used sails.

What is the size of your sail? Steadying or propulsion?

I do drive to Seattle every couple months. I will look them up.

 

[Bob Cofer]

What is the size of your sail? Steadying or propulsion?

I do drive to Seattle every couple months. I will look them up.

It is for steadying. 7' on the foot and 8' on the mast.

 

[LeoKa]

I've measured my setup yesterday. Boom 10', mast 9'. Mast end x boom end 13'.
The boat is 32T empty, 36T loaded. Draft 7.4', beam 14.2'.

 

[long-cours.62]

I see. So the purpose of your sail were propulsion, not steadying?

The jib was fitted because ...the mast was already here and we we already had this jib.
The main sail could be used for both.
In our example 15kts of wind could make a "pressure" of 3.8 kg per sqm x 17 sqm x by the high of the center of the main sail it dampen the roll. even "only" the inertia given by this weight dampen also, it change the...don't know the term in English :-(
And if need to use like only a steady sail it is relatively flat sail and full battened, it do the job.

 

[KnotYet]

Deploying when the boat is rocking and rolling is not fun. Seldom does a sailboat motor into a wind and then set sails. Sailboats have the gear in place. Anyway, I ruled out a steady sail when had had the GB with mast and boom.

I can assure you that most sailors prefer to raise sails while luffing (pointing into the wind) to minimize the effort needed to overcome the friction of the hanks or cars and track.
Setting, which to me means trimming, happens as you fall off onto a chosen course.

 

[Marco Flamingo]

Given what you have said about your vessel's stability in other posts, I don't think that a relatively tiny "steadying sail" would be of any benefit. It could even make things worse. It's probably time for a real stability analysis and determine what, if anything, can turn the boat back into a coastal cruiser.

 

[LeoKa]

And if need to use like only a steady sail it is relatively flat sail and full battened, it do the job.

Thank you for sharing. This is very useful information.

 

[LeoKa]

Given what you have said about your vessel's stability in other posts, I don't think that a relatively tiny "steadying sail" would be of any benefit. It could even make things worse. It's probably time for a real stability analysis and determine what, if anything, can turn the boat back into a coastal cruiser.

I hear you. Nothing is final on this, yet. I might just totally abandon the idea, but for now, I wish to hear others' opinions and experiences.
Who knows, the mentioned tarp test might not deliver any significant results, so it will not make sense to spend money on the properly designed steadying sail.
If I wanted to order stability analysis, I would properly do it for a more serious solution. My boat is not a high-end vessel, so serious money spending might not be justified.

 

[SteveK]

I can assure you that most sailors prefer to raise sails while luffing (pointing into the wind) to minimize the effort needed to overcome the friction of the hanks or cars and track.
Setting, which to me means trimming, happens as you fall off onto a chosen course.

you sir have replied to a sailor, the OP however may not seem to be one. And as you will know a sailboat headed into the wind is more stable than a powerboat.

 

[GoneFarrell]

I'll throw this in as food for thought..

FinDelta #2 "Classic" Anchor Riding Sail for Boats 33 to 46 Feet

FinDelta Classics can be seen holding yachts steady in windy anchorages around the world. As a safety feature, the forward fin portion is international orange, making your boat easy to see in rainy, foggy weather. You'll sleep sounder.

www.bannerbaymarine.com

It's an anchor riding sail. I have not used one, have seen one in the San Juans. If I get industrious I will prototype one from tarp material this season as my boat can tramp bad on anchor.

 

[psneeld]

Getting sidetracked on riding sails is usually the demise of decent discussions of steadying sails..... which I think was the OP idea.

 

[psneeld]

Steadying sails use air resistance (nothing to do with propulsion and why they don't need sail "shape") when rolling to reduce the motion the same way anti-roll tanks use the liquid weight opposing gravity to do the same.

Thinking steadying sail have anything to do with sailing is already a bad assumption.

 

[RedRascal]

I've measured my setup yesterday. Boom 10', mast 9'. Mast end x boom end 13'.
The boat is 32T empty, 36T loaded. Draft 7.4', beam 14.2'.

Okay it looks like a $13 test instead of $20 That's a 35% cost reduction, when in boating do you every get a chance to spend 35% less to do something. 9 ft. 4 in. x 11 ft. 4 in. Heavy Duty Reflective All-Purpose Weather-Resistant Tarp

Given that you are only working with about 45 square feet of sail area I am thinking it won't do anything other than provide some shade when the sun is lower in the sky. So back to voting with my wallet and I am thinking I'd rather spend my $13 on a nice apple or key lime pie.

 

[Marco Flamingo]

I'll throw this in as food for thought..

FinDelta #2 "Classic" Anchor Riding Sail for Boats 33 to 46 Feet

FinDelta Classics can be seen holding yachts steady in windy anchorages around the world. As a safety feature, the forward fin portion is international orange, making your boat easy to see in rainy, foggy weather. You'll sleep sounder.

www.bannerbaymarine.com

It's an anchor riding sail. I have not used one, have seen one in the San Juans. If I get industrious I will prototype one from tarp material this season as my boat can tramp bad on anchor.

I just bought several yards of spinnaker material and made a delta sail after looking at the $550!!! FinDelta #2. I spent less than $30 on materials and maybe an hour and a half at the sewing machine. Yes, it is lightweight, but I'm only looking to point into the wind better when at anchor. If it only lasts ten years, I'm good with that. I'll start another thread with pictures when I get a chance.

As psneeld said, a steadying sail generally uses the air resistance when flopping back and forth. If the vessel's flop is slow (from low stability) and the mast is short (short moment arm), you get nothing. If the wind is really strong on the beam, you will get "pinned" to one side where the vessel's stability "kicks in" based on the moment arm created between the CG and the CB. With a low stability vessel, that might pin you over with a constant 5-7 degree list (a stability test would give some indication). Probably not where you want to be in a trawler even if the overall roll is reduced.

But I'm all for a cheap blue tarp experiment.

 

[LeoKa]

Getting sidetracked on riding sails is usually the demise of decent discussions of steadying sails..... which I think was the OP idea.

True.

 

[LeoKa]

But I'm all for a cheap blue tarp experiment.

Yeaahhh, welcome to the team.....

 

[LeoKa]

Okay it looks like a $13 test instead of $20 That's a 35% cost reduction, when in boating do you every get a chance to spend 35% less to do something. 9 ft. 4 in. x 11 ft. 4 in. Heavy Duty Reflective All-Purpose Weather-Resistant Tarp

I vote for tiramisu. Not really a pie person.

I like cheap, but sometimes boater need to swallow the expensive whatever. Even, if there is valuable result, I think it is still money well spend of $20. I might just learn something about my boat.

 

[SteveK]

Do you have a fin or full keel on that boat? Either should already reduce rolling. Do test the tarp sail idea before getting a sail made.

 

[LeoKa]

Do you have a fin or full keel on that boat? Either should already reduce rolling. Do test the tarp sail idea before getting a sail made.

Full keel. It is a sailboat hull originally. 7.4' draft. Keel tanks both sides.
Tarp sail first, agreed.

 

[long-cours.62]

One précision concerning our Lo g cours 62 with the orange main sail : maximum stability at 48° is 18476 m/kg

 

[cafesport]

Your mast and boom are not going to provide sufficient sail area. Windsurfing sails are bigger. Put 20 lead pigs in the keel area and your boat will immediately be stiffer.

 

[LeoKa]

Your mast and boom are not going to provide sufficient sail area. Windsurfing sails are bigger. Put 20 lead pigs in the keel area and your boat will immediately be stiffer.

Yea, lead or bilge keels, are still in the picture. The steadying sail is just an idea. The suggested tarp test could answer some of the dilemmas.

 

[Pascall]

We can hoist two sails on our boat, mizzen sail and a jib, together 12 square meters.The boat is 11 meters long and weighs 14 tons.It helps reduce rolling but to a limited extent.In a certain sea state it can help quite well, but it only takes a little change (worse) and it is nullified.In other words, the sail area is too small for the weight of the boat.

Greeting;

Pascal.

 

[LeoKa]

Yes, I think the boat is too heavy for a small sail I can create. I still want to test it with the tarp, but I don't have high expectations.