New Boat design

[grady]

The hydrofoils are horizontal, which is perpendicular to the daggarboards. This allows the vertical forces to be applied to each side.

Twin daggerboards I get. What if you canted them out so when you are heeled over 10 to 20 deg the boards are stright down to be more efective? However lift=drag. With the dagerboard 1 to 2 foot off of centerline at best you will get 2lbs of righting moment for every 1lb of lift. Probably will be more drag than power?

There are some righting foils made that stick out of the side of the boat. They help a little but most are about 10 foot off of centerline. 1lb of lift would give 10lbs of righting moment.

[Chopper Pilot]

I wanted to initially, but the stress over the life cycle of a daggerboard at its root would not last long. But I suppose the dagger can be a high lift, asymmetrical daggerboard! I may even employ a gurney flap. In aviation, it has been found to decrease drag coefficient while increasing the lift coefficient, though the density that the foil goes through is very different. Again, this is just a goal, or thought experiment that I hope to build.

[Chopper Pilot]

I have changed the hull a bit. I am also unsure of how I want to design the hatch entryway. Not sure if I should go with the standard top hatch. I would like to have it slide open on the floor in the cockpit, that way I could have enormous room inside. But if I made the standard top hatch, I could make a pocket for the front hatch to drop into so people wont need to remove and reinsert all of the time. They could just pull it up, or drop it into its pocket on the back side of stairs.

[grady]

I wanted to initially, but the stress over the life cycle of a daggerboard at its root would not last long. But I suppose the dagger can be a high lift, asymmetrical daggerboard! I may even employ a gurney flap. In aviation, it has been found to decrease drag coefficient while increasing the lift coefficient, though the density that the foil goes through is very different. Again, this is just a goal, or thought experiment that I hope to build.

Asym dagerboard could work. I would not do a gurney flap, The only time I have put those on was to fix an engeneering F... U.

[RobertB]

Now I remember what that bow reminds me of


Wonder if Highlander has tried that sail plan yet

[Chopper Pilot]

Now this is more like it! 10' Beam and 34' long

[Ixneigh]

That bow shape, as well as throwing spray , it's going to make getting any anchors up without hitting the hull difficult. You certainly won't pull it up by hand.
Ix

[mastreb]

For a trailerable, I think you'd want to maximize interior volume vs. trailerable length. I'd go with an absolutely plumb bow and stern--Straight up and down.

I'm partial to the look now though



Also, I'd consider doing the owners a favor and doing two mast arches, one at the cockpit forward and one aft. Atop the forward you would locate the traveler, keeping it up and out of the deck. Always a good thing for small cockpits. The aft arch would be for mounting electronics out of the way and not on the removable mast, also dinghy davits, solar, etc.

Also, a Bimini or cockpit enclosure is now nothing more than a series of snaps and canvas to enclose those two arches.

Your mast could then hinge at the same height as the arches, just above the boom but below the sail track. Your boom will then rest on the forward arch while traveling, and the mast rests just above it but parallel to it on the aft arch. Roller furling boom and you've got your mainsail managed for trailering.

Masts are getting even less "solved" on boats of this size. At 34 foot length, you'll want a 45 foot or so long mast for anything approaching a typical aspect ratio these days. That's getting hella complicated to manage raising and lowering.

[Chopper Pilot]

Super good idea with two arches! Also, I will change the 35 foot mast to a 45 footer. It sure seems tall. I assume you are measuring from water line.

Maybe I should ketch it

[Russ]

34 x 10 is going to be a heavy boat on a trailer. So plan on some beefy trailer and tow beast.

Matt is correct about mast size. 45 from deck would probably be a normal aspect ratio....that also makes for one heavy monster to raise without a lift. My Hunter mast was 47' long and took 4 or five guys to lift. It's not just the aluminum, but all the heavy SS rigging that goes along with it. The Seaward is a low aspect, your boat is looking like a high performance high aspect boat.

I'm not digging the cockpit on this. Looks too much like 60s era powerboat. Very sleek and sexy, but not very functional. I would think a larger uncovered cockpit with maybe an arch for rigging would be more functional.

[Chopper Pilot]

How about this hard top?

[Russ]

How about this hard top?

Not a fan of hardtops on sailboats. That's what canvas is for. Can be taken down and used when needed.

Cool CAD work.

[Chopper Pilot]

The original arch is still there, this just hooked over it. It is an attachment to the arch, not one piece

[Chopper Pilot]

[mastreb]

Were I designing a new power sailor from scratch, I'd forgo standard rudders entirely and use two long-shaft outboards with folding props, port and starboard. This keeps the center transom open for passage, and dramatically reduces steering system complexity.

The idea is simply that the outboard skegs are the rudders. Once you turn the motors off at speed, the pressure of forward motion against water will cause the outboard props to fold into their axis (think flower folding in). As soon as you run the motor, centripetal force cause them to fling back out. The folding is worth about a 1/2 knot of speed in reduced drag, and these props are professionally made for keelboats in two and three vane configurations. I'm not aware of anyone who makes them for a high-speed motor, but I'm sure they're out there; worst case you can have them made.

Now to raise rudders you're just using the hydraulic ram on the outboards. You have rudders that can stand up to all engine speeds without needing to be lifted, and you have the ability to engine start and run without having to lift rudders and drop motors.

You also get the advantage of using two smaller outboards and having the ability to rotate the boat using the outboards, which with a high-windage power-sailor is rather important.

If you find you're not getting enough bite with stock skegs, simply bolt more foil on the bottom to make the skegs deeper. Use sheer quick-pins so you can take the skeg extensions off and so they'll preferentially break off if you strike something underwater.

For the steering system itself I would just use an autopilot ram and steer-by-wire, with an emergency tiller that can be rigged center-transom to move the steering bar that connects the motors against the hull. This gets a bit steering wheel out of the center cockpit--I would put a large helm wheel forward (in the vee-berth) with full wrap-around glass to make a pilothouse for high-speed motoring inside, and just use small autopilot power-steer controls on the port and starboard gunnels or cabin top for sailing. This way you get maximum cockpit space for trimming and entertaining.