new design

I've been working on this for about a month or so off and on. Its a 20ft sharpie to be built out of ply or foam. It has a daggerboard instead of a centerboard and a freestanding carbon rig. I've attached the plans as they are thus far, my little blurb about designing it and a rendering done in flamingo. I'd appreciate comments, insight, suggestions. The whole thing was done in Rhino. I will be adding to and updating the plans, as folks make suggestions and my own research.
Thank -Steve

 

Some suggestions -

It's a nice looking little boat, and looks very buildable, which is nice! I have a real soft spot for the sharpies. Are you paying attention to the heeled underbody? These things are much better goers than they ought to be, because they sail to weather on the chine, so if you get that heeled underbody wrong she can be crank and slow.

A couple of major things seem to me to be missing:

• discussion of mast step (do you need some stringers etc?)
• discussion of mast partners
• discussion of sprit supports

To a lesser extent, you might need to address strong points for sheeting as well.

Finally, I am curious as to why you suggest laminating a toe rail up from glass and foam. Why not use an existing (for example) an off the shelf aluminium extrusion, or wooden moulding?

 

I haven't really worked on the rig yet, other than to do the rendering. As for the toe rail, there is no real reason not to use an existing extrusion. I would probably use foam only if I built a cored deck instead of a ply deck. The underbody looks pretty good at 15 degrees of heel. I'll add a page to the plans with diagnals. I want to get vpp software soon and when I do that will be on there too. -Steve

 

Oh, so you'd do a foam toe rail and just build it right into the deck? Basically, glue down a foam strake on the foam deck core, and the glass over the whole assembly?

 

Yes, I should make that clear on the plans. When I do a sail plan I will show the areas that should be done with a higher density foam or ply. I'd attach as much as possible to the bulkheads to keep as much load as possible off of the hull skin. All that applies to a foam build only, I don't think a ply hull and deck would require all that.

 

I have one question.

How are you going to hold the luff of the jib tight.

Are you going to have swept back shrouds or running back stays?

My guess is that the pointed stern is so you don't have to cut any curve into the side planks. Am I right?

A pretty cool boat, though.

 

I have one question.

How are you going to hold the luff of the jib tight.

Are you going to have swept back shrouds or running back stays?

My guess is that the pointed stern is so you don't have to cut any curve into the side planks. Am I right?

A pretty cool boat, though.

 

Nice boat

Steve,
That is a nice looking boat. Similar to 20' Maryland Crabbing Skiff described in Ruel Parker's The Sharpie Book. I have aspirations to build something similar in composite panels made on a mold board. Hard chine boats lend themselves to that type of construction. Maybe next year. Shop is in the final stages of completion.
James

 

I used the 20' Maryland Crabbing Skiff offsets to start this boat off. I faired the sheer and chine and added the transom. The lines have been tweaked slightly to allow for developable surfaces. The sides can be cut from 3 sheets of 4x8 ply, the forward 18" or so will be a separate plank but the rest would be one long panel. The rig so far is pretty much just for the rendering. I did the sails to get the center of effort so I could place the daggerboard but have not gone beyond that on the rig. Unfortunatly, my laptop died a few hours ago and it will take a couple weeks to get my new one. A rig plan as well as fullsize drawings of the bulkheads were what I planned to do tonight but that didn't workout.

 

Also, the planset.pdf attachment has the layout for the side and bottom panels. There is curviture cut into the side panels. This pdf can be printed on regular 36"x24" paper and when I get my new computer there will be fullsize patterns for the bulkheads and possibly the stations for a building jig as well. I want to stay with an freestanding rig and the only reason I can think of to add standing rigging would be to put an assymetrical chute on her. I'd use swept back shrouds, probably around 15-17% to keep away from running back stays. I don't think the transom is wide enough to make them very effecient. I haven't done the math on for it yet, something to work on while waiting for the new laptop.