New Boat design

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Chopper Pilot
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New Boat design

Post by Chopper Pilot » Mon Apr 06, 2015 10:28 am

Here is a little 28ft boat I pounded out on CAD last night that I am thinking about building. It should easily fit on a boat trailer. The bow is a penetrating bow. It uses hydrofoil dagger boards that raise and lower. It will also have two outboard motors that lower down through the hull like some catamarans. It will have low side water ballasts instead of down the middle. With the water ballast on the sides, it will have a righting moment the second one raises slightly out of the water. Also, while underway, the hydrofoils can adjust pitch to right the moment. This will give it a lot of sail area to go zoom zoom. I do hate the 26M's transom entry. There is no room! So I made the transom on this one easy to get in the boat, with no motor in the way. I made the window vertical, like a lagoon catamaran, to receive a ton of wind. I made the arch to mount the sheet traveler so it would be out of the way. I tossed around the idea of making it out rigger capable, but this is a planeing boat also. With the hydrofoils raised up to the bottom of the hull, it will have a nice stable area to give the boat good planeing capability. I had even thought about the two dagger boards being swing keels that would reach the back, just couldn't make it work
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Chopper Pilot
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Re: New Boat design

Post by Chopper Pilot » Mon Apr 06, 2015 10:29 am

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RussMT
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Re: New Boat design

Post by RussMT » Mon Apr 06, 2015 11:43 am

Sexy little boat. And so shiny. 1000 points for style. Very nice. And of course it will be super fast with that blue color.

2 outboards? Hmm...where? I don't see a place for them. I can't see room on a 28' boat. Why 2? Would they be big motors?
I had a friend who owned a Clipper Marine with an outboard in the center of the boat. Clever idea because it kept the prop in front of the rudder and was acted like a pseudo inboard. Lever idea, but in practice didn't work. The exhaust had to be vented with a blower. Problem was the outboard alternator couldn't keep up with the power requirements of the blower. So do you have a good plan for the outboard exhaust?

Your daggers appear parallel. That would only add more drag without much benefit of having 2. Unless they were angled to take advantage of heal. I'm not hydrodynamic engineer, but it looks like too much drag.
I like the arch. Very modern style. The Tattoo should have designed something like that. When I see this design, it looks like it would make a good catamaran.



Good luck with this. Would LOVE to see it built.

BTW, the water ballast doesn't have to be lifted above the water line to work. Took me a while to understand this. I still struggle with the concept.



--Russ

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Chopper Pilot
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Re: New Boat design

Post by Chopper Pilot » Mon Apr 06, 2015 12:47 pm

I have not worked out the exhaust yet, but the purpose of two engines is less for speed, more for redundancy. I also tossed around the ideas of using jet ski motors and compressors. But the catamaran style outboards that are lowered from columns inside the hull is just easier. Might require a V-birth in the rear, who knows. The back deck will be the focus of living. The insides focus is bathroom, kitchen, and beds. The two dagger boards sole purpose is to provide righting moments from the hydrofoils, otherwise I would have used one.

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RussMT
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Re: New Boat design

Post by RussMT » Mon Apr 06, 2015 1:03 pm

Chopper Pilot wrote:I also tossed around the ideas of using jet ski motors and compressors. But the catamaran style outboards that are lowered from columns inside the hull is just easier.
I own a couple of jet skis. The motors aren't designed for cruising or long journeys. Quick HP and acceleration, not big on durability. They are totally cooled and dependent on the jet pump. Modifying that aspect would be a PITA.

Love your ideas and thinking outside the box. Nice to see cool trailerable designs.

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Re: New Boat design

Post by Chopper Pilot » Mon Apr 06, 2015 1:57 pm

I did say jet ski engines, but would modify by using 13b winkle engines(zero vibration)

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RobertB
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Re: New Boat design

Post by RobertB » Mon Apr 06, 2015 1:58 pm

The interior should be quite interesting with twin dagger boards - and twin internal retracting motor and their wells. And how does the single rudder under the hull work?

As I see it, a 26 foot boat. The narrow stern and internal motors and motor wells should take up at least the aft 6 feet - the forward placement of the motors should offset the extra weight. How do the motor wells interact with the cockpit (access, vertical height)? The bow floatation and anchor locker should take up the forward 4 feet of usable space. This leaves 16 feet max interior space - cut in half by the dagger boards. What is your idea of the interior layout?

Penetrating bow - very Zumwalt like (how do you expect your turning stability to be, the Zumwalt is pretty unstable). I recommend a periscope in rough water - the standard :macm: makes for a very wet ride - this one should be very interesting.

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Re: New Boat design

Post by Ixneigh » Mon Apr 06, 2015 3:18 pm

The M is a dry boat under sail though. I really like that about it since I hardly ever power at full speed

Ix

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sailboatmike
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Re: New Boat design

Post by sailboatmike » Mon Apr 06, 2015 4:58 pm

Hi guys

There are a few Australian boats designed with twin swing keels, the designer was Ozzie Whittley his boats were designed to sail in Westernport, a smallish shallow bay with lots of mud shoals in Victoria down in the south of Australia.

The swing keel housings are inside the cabin couch storage areas this allows the boat to have a flat floor in the cabin itself making the boat quiet large inside,

For more information google Aloora 23, Jeda 22 or the Kestral 18 (There is also a New Zealand Kestral thats not related to the Australian boat)

All these boats are displacement hulls but are renown for being tough stable boats with numerous crossings of Bass Strait (200Km wide between Australian mainland and Tasmania) , which is considered one of the nastiest bits of water in the world, with huge seas that build quickly, high winds and strong currents.

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Re: New Boat design

Post by RobertB » Mon Apr 06, 2015 6:59 pm

Ixneigh wrote:The M is a dry boat under sail though. I really like that about it since I hardly ever power at full speed
Ix
I have heard that :) but my experience is under power including the time I thought the other Mukkers were ahead of me (the last MuckAbout) and I was trying to catch up (they were holed up and I was the only one to go out in the weather :? ). My bow spent a good deal of time under water, the cabin had water pouring in through the CLOSED hatch, and the pilot (me) was thoroughly soaked :P .

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Ixneigh
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Re: New Boat design

Post by Ixneigh » Tue Apr 07, 2015 8:46 am

Ive only actually ever had the bow go under water a few times and the dogs made me promise that we'd never be out in that weather again :D :D :P
Ix

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RobertB
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Re: New Boat design

Post by RobertB » Tue Apr 07, 2015 5:18 pm

Ixneigh wrote:Ive only actually ever had the bow go under water a few times and the dogs made me promise that we'd never be out in that weather again :D :D :P Ix
I bet your dogs were alot nicer about it than my wife (although her dog at the time looked almost as bad as she did) :?

Did I mention that I had one of my sons holding onto the pulpit and going under also :? :? :? That did not last long. This is the same one that was riding on the outside of the hull holding onto the lifeline when we first sailed over 25 degrees heel :P

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J--
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Re: New Boat design

Post by J-- » Tue Apr 07, 2015 8:29 pm

My only thought on this is it might work....BUT!

You're going to need to make this craft out of some very exotic light weight materials to get it to foil. You'll also need foils on the rudder as well. Finally, I think the rig is going to be a bit undersized based on the foiling Moth's I've seen. You'll want a very roach-y main like a wind surfer, or skip the main altogether and go with a wing and a kevlar jib.

I think it's cool, but based on those criteria to make it work, I know I couldn't afford it! :(

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Chopper Pilot
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Re: New Boat design

Post by Chopper Pilot » Tue Apr 07, 2015 9:40 pm

the hydrofoils function is not to lift the boat out of the water any. It is only there to provide a righting moment to the hull as air tries to heel it over. They will be used to pull one side of the hull down while pushing the other side up

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grady
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Re: New Boat design

Post by grady » Wed Apr 08, 2015 7:34 am

Chopper Pilot wrote:the hydrofoils function is not to lift the boat out of the water any. It is only there to provide a righting moment to the hull as air tries to heel it over. They will be used to pull one side of the hull down while pushing the other side up
The way they are depicted they will not provide righting moment? A airfoil to help righting moment needs to be horizontal to keep the boat from having more leeway.

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