Steadying sail design/rigging?

[psneeld]

I didn't try to be cavalier in any way...it's just that you have a boat pretty well outside the norm for many of us and discussing those eccentricities are not easy for me.... lots of practical experience without the technical background to be sure I am getting my points across. I did have to teach stability in captain's licensing courses...but again they were geared toward operations and not really design.

I started thinking about the tank removal but again...that could be a lot of work and not really needed to accomplish what you want/need.

That's really the main reason a quick eval by a set of eyes that actually does this stuff for full time...it may cost up front but save in the long run and give alternatives better than people like me that understand basics but only enough to be best guesses.

At some point it really depends on how much you love the boat but genuinely dislike it's rolling and how much would you spend to keep the boat and solve the problem.

 

[LeoKa]

At some point it really depends on how much you love the boat but genuinely dislike it's rolling and how much would you spend to keep the boat and solve the problem.

That is correct. Luckily, I do not have to make this decision very soon. If I decide to sell the boat, it will not happen for another 10 years. So, plenty of time to search for solutions.
To me, all of your messages are pure education. I appreciate any clues and thoughts, since I do not know anything about design. Moreover, I am learning about my boat as I fix things and start new projects. Luckily, as a retired person, I have plenty of time.....

 

[sean9c]

Yes, I certainly will involve a NA for major steps.
As of now, I am just learning about the options. I have no plans to sail anywhere anytime soon, so I am safe in the marina for now. Once the options are narrowed down and the budget is available, I will work with a NA and follow the recommendations.

The keel tanks are completely full with diesel now, so I just leave them alone. Who knows, the NA I will hire might recommend to completely remove them, and/or remove the air tank at the stern, as well. This way, the original hull shape could be restored almost, just as BR designed this motorsailer originally.

The changes to the original BR design were made by an NA to try and somewhat compensate for the diversions made, like the large steel superstructure and large engine, from the original BR design. As I remember, it's been a long time, before the changes the boats behavior and lack of stability was thought to be dangerous. Any thought of being able to go back to something close to the original design I'd think would have to include a very hard look at that superstructure, which is the root of the problem. I'm guessing that won't be acceptable. Maybe you can find a different NA with a different take on an answer, you're basically trying to fit a much bigger hull under that house, but it won't be easy.

 

[LeoKa]

Maybe you can find a different NA with a different take on an answer, you're basically trying to fit a much bigger hull under that house, but it won't be easy.

A bigger hull? What do you mean by that?
I am searching for a NA already, I just need another haul-out to get the required measurements a NA will need.

 

[sean9c]

A bigger hull? What do you mean by that?
I am searching for a NA already, I just need another haul-out to get the required measurements a NA will need.

A larger volume hull, it'd doesn't need to be longer or wider. That's what your mods are trying to achieve.
The big steel superstructure has raised the center of gravity, reducing the stability. A larger hull would give you the added stability and buoyancy you're looking for. In your case a pretty good example is that bustle in the stern. The goal was more buoyancy to help reduce the squatting the boat had. So now you're grafting on a tank to try and add that. So how do you fair that tank into the hull? You can't, so you try and resolve it somehow. Appolonio's solution was that horseshoe shape. Not ideal but it's what he had to work with.
Out of curiosity how do you know what measurements a NA would need? My guess would be that would change with the NA and I'd not think that any NA would proceed without seeing the boat out of the water to try and get a better understanding.

 

[LeoKa]

Out of curiosity how do you know what measurements a NA would need? My guess would be that would change with the NA and I'd not think that any NA would proceed without seeing the boat out of the water to try and get a better understanding.

I don't. It was just an idea. Some of the NA are not local and cannot come here when I haul out. I thought I could make some measurement to help with process. I could be wrong.
Certainly the best way to go to bring someone onsite for the initial planning. I hope I will find someone before summer.

Given the present stage of the hull, what additional volume could be added?

 

[LeoKa]

sean9c

pm sent

 

[trawlercap]

I only read the opening question. I got a $20 triangular sunshade from Amazon. They have lots of sizes shapes and colors. The three edges are hollow cut to tension flat, no belly. With 10kts of wind it helps for sure. At 20 kt (4 times the force) in no current it’s a big improvement
Rigging it up is a creative process. I’m getting a bigger shade to play with. Best bang for my nautical buck yeet!
“The only thing cheap in this boat is the owner”

 

[trawlercap]

Steadying sails are in my opinion one of the least understood topics on TF.

Many have no idea that steadying sails, riding sails and propulsion sails all have specific duties and are designed and placed differently.

Jay Benford the yacht designer has done some writings on steadying sails that I have studied....find some of his writings if you can.

I my experience and research...they should be designed to be flat, hard cloth, sheeted and trimmed in hard and flat, as tall or high as possible. They are designed to act like a sheet of plywood that counteract roll with air resistance. It is more akin to a storm trysail with very little draught. If made from a used sail, ensure it is heavy cloth and the draught is removed.

Search TF for past threads and understand that steadying sails need to be much larger than what many "trawlers" have in the was of mast/boom setups....and these threads are full of what I think is questionable info.

Yes! See my last comment in this old thread.

 

[trawlercap]

If I had to vote on this with my wallet I'd do a test with a silver tarp. 11 ft. 4 in. x 15 ft. 6 in. Heavy Duty Reflective All-Purpose Weather-Resistant Tarp

Cut the tarp to the shape of your rig. You don't need to get too fancy with clew and head of the sail. Just knot up those ends and lash them with some line. Go cruise in the common roll scenario you generally encounter and see if it makes a difference once you raise the sail. Even if it blows out after a 1/2 mile that should give you enough information to know if it made a difference or not. I don't think you can go too wrong doing a $20 test with a tarp and it's something you should be able to do quickly.

A $20 triangular sunshade has hollow edges and under tension is flat