hard-chined 24' ply/glass sailboat- question

[molerocket]

Hi, folks. Newbie here with another question, I've been helped greatly by you folks in the past. I'm slowly designing the weekend cruiser/camper sailboat of my dreams- the idea is to build it myself out of ply and glass.

Not sure how it will be powered yet (besides sail) and My ideas for an outboard are causing problems with the rudder placement.

I did hit upon the alternative of placing the rudder forward, as a hinged part of the keel below the mast. has this ever been done/is there a flaw with this idea? it seems somewhat elegant to me.

the reason i'm particular about engine/rudder placement is because as a homebuilder I don't care much for solutions that weaken the hull or increase the maintenance. worried about inboard propshafts/potential for leakage, etc.

if nothing else can you recommend a book I should be looking at?

Thanks for anything,
Casey
PS soon i'll have images of the design.

[molerocket]

here are some views of it. I'd be happy for feedback on the hull shape; the rest is still just rough stuff.

the idea with the forward rudder is that the post runs up a column just aft of the mast to a tiller below the ceiling (not shown) which will be cabled to a steering wheel.

there will be a cutout on the transom below the 'poop deck' for an outboard, if indeed I go that route.

[gonzo]

The outboard is usually hanging from the stern. How does it interfere with the rudder?

[frosh]

I would say that if you sail her backwards, she will steer quite nicely. However going the regular direction looks to be a problem of simple physics to me. If you can make it work, you must know something we don't.
Why don't you worry about getting the sailboat part designed first in a more conventional way.
Auxillary power by outboard motor is really easy to do. Go take a walk at you local marina and see how other small cruiser yachts mount their motors.

[gonzo]

I own a boat with an outboard in a lazarette well. The rudder is a balanced hung type and does not interfere with the motor at all.

[molerocket]

I appreciate the input folks. You're right about the fact that there must be a simple way to get both a rudder and an outboard at the stern; everyone else does it. Because of my design ideas (such as cockpit seating upon the transom giving the appearance of a poop deck) things are a little more complex. It will be worth it for that level of exoticism I think.

Does the hull shape look sound? I'll rework the keel.
Casey

[gonzo]

The keel looks too big. Why do you want a multichine instead of single chine? Is it for the looks? It complicates construction and looses interior space. Performance is the same or less. They also usually pound more on head seas.

[molerocket]

Well, my gut feel was to go for a V-shape rather than a |_| shape, just for stability's sake. I have no investment in the shape. I'd like it to be a simple build.

Come to think of it though, a weighted keel will keep the boat upright even with a flatter bottom - right?.

Thanks for your tips and pointed questions!
Casey

[gonzo]

I mean a vee bottom with only one chine per side. When the boat heels upwind the sharp chine cuts the water.

[molerocket]

you mean like this?

[frosh]

Hi Molerocket, not meaning disrespect by this, BUT---! You have not addressed the steering problem, which was meant in my earlier posting in all seriousness, and your underwater keel/rudder arrangement is quite suspect. I also detect from your postings already that you are very new to this whole boat design thing. You need to ask yourself as honestly as possible, am I really knowledgeable enough to design a 24 ft. sailboat myself at this stage? If you think yes, then are you prepared to spend the many $ thousands building your design and maybe finding out it basically won't sail?

[gonzo]

This is my usual advice for beginners: make a cardboard model. A hotglue gun, tape and cardboard will give you a good idea of how the boat will look and if you have akward shapes. Also, you can test for stability in your bathtub or pool. I would suggest something around 24-30" long.

[molerocket]

Frosh: I take your words quite seriously, and am trying to address the steering! my boat, along with my life, is a work in progress, and I hope with refinements, tips, and test models, things will always approach greater perfection.

below is the revised keel/steering arrangment, with the motor mounted off-center at stern.

[frosh]

Hi Molerocket, the latest plan posted is an improvement but needs much more refinement. I would refer you to the thread under multihulls which is worth reading. http://boatdesign.net/forums/showthread.php?t=13162

[molerocket]

Again, thanks! I read that thread and I definitely fall under the designer/builder heading. is there a textbook or similar that I should be reading? I would really like to build this one day but I want the design to be a lot more refined.