10 foot SWATH

Tom where have you seen counter productive dialogues here?

Richard

[peterAustralia]

To amaurer,

Does your craft need to be limited to 10ft (is that a requirement)

If it was up to me, that is to design a 1000lb craft for 4knots, I would copy a Nigel Irens design. He has done some very impressive trimaran motor vessels, with small outriggers. The outriggers is smooth water just touch the surface, and as such have small drag.

The main hull can be deep and narrow for good wave piercing ability. The batteries can be down low here, only in the center hull, in order to keep the radius of gyration low (correct term? I mean keep the weights close to the center of rotation of roll). The main hull could be 20ft the smaller hulls about 8ft

Does your craft need a small turning radius for work in confined waters.

Are you looking for columbian drug running semi-submersibles in tropical rivers?

For self righting, a trimaran can have outriggers that rotate and can also be filled with water, using 2 in cooperation could assist in self rigthing.

Something weird, if the central hull has a couple of circular sections, and the outriggers can be changed in angle by about 20 degrees, Then in unlikely event of capsize, the outriggers could have their angle adjusted a little and the upside down main hull rotates 180 degrees inside it's circular ring frames and continues its voyage.... its just an idea......In other words the craft can continue if upside down by adjusting crossbeam angles and rotating the main hull

peterAustralia.

[amaurer]

10 feet is not a requirement, the only requirement is total deck area that fits my three 3x5.5' panels.

As you suggest, a 20 footer also accomplishes this, and perhaps better. I, however, have no real stability requirement, so the trimaran configuration is unnecessary.

[Stumble]

Amaurer,

I know this is a bit of a change from the discussion so far, but have you considered a canoe? They are very efficient hulls at low speed, can be had for cheap, and if you were to place a watertight deck over it would likely be self righting with little additional work to be done. Something like the Kruger Seawind is designed for heavy offshore work.

Mounting the solar panels high may cause a bit of a stability problem, but by mounting 1000lbs low in the boat I doubt this would be much of a problem, though I am not enough of an engineer to really tell you.

[Ad Hoc]

armaurer

"..I see you've exhausted the extent of the advice you're willing to give, so thank you for that, in any case..."

The advice is limited by your replies. Since i see no attempt at that which i have suggested in #21. So no need for any further advice.

[dskira]

Since it will be unmanned if I understand well, a very cambered deck will give your SWATH hull the self rifhting without almost any ballast. But the deck should be like a turtle back. Some watertignt hatch will give you the necessary access.
Quite cool a 10' SWATH. You can try several configuration of SWATH without braking the bank by doing some rough models. It will give you some idea and will, with your caculations, give you some good direction to take. I hope to see the 10' SWATH in the water soon, quite a very nice vessel to do. Can be also a valuable test for a bigger one!

[dskira]

Amaurer,
This is SWATH in testing, perhaps 4' long.



As I says to my previus post, I think your project as you descrived can be realy succesful. Some trial and error are always necessary, but fun and valuable to do.

Originally Posted by dskira

Amaurer,
This is SWATH in testing, perhaps 4' long.



As I says to my previus post, I think your project as you descrived can be realy succesful. Some trial and error are always necessary, but fun and valuable to do.

This is a SWATH ??? Are you sure???

Originally Posted by dskira

Yes it is

I´m not convinced.
The struts look pretty fat (too fat?), the submerged hull is invisible here, but surprisingly the bulb is visible???
Some slightly larger examples:

[gonzo]

On post 33 you say you have no stability requirements. Are you really meaning that or just being obnoxious?

[Ilan Voyager]

Originally Posted by apex1

I´m not convinced.
The struts look pretty fat (too fat?), the submerged hull is invisible here, but surprisingly the bulb is visible???
Some slightly larger examples:

I agree with you Apex, a very peculiar cat, but not a true swath. It seems hard to get an effective decoupling with a such shape. What would be the interest of a swath shape on a 10 feet hull? The size and height of a swath is loosely correlated with the size of the expected waves. What's the purpose of a such "drone"?

[amaurer]

Originally Posted by gonzo

On post 33 you say you have no stability requirements. Are you really meaning that or just being obnoxious?

Oh come now.

I require a stable design, in the sense that it must return to its upright position (as I mentioned), but indeed I do not have a specific criteria for roll stability margin, as the ability to survive an indefinite number of rolls is a natural requirement for an unmanned craft with limited ability to steer during weather, and I have no crew to keep happy. Of course, the most ridiculous of designs that roll when a butterfly lands on them would be problematic, but lets not get too pedantic here - this is solely a personal project.

Originally Posted by Ilan Voyager

I agree with you Apex, a very peculiar cat, but not a true swath. It seems hard to get an effective decoupling with a such shape.

Ahh Ilan, there we have our answer! Look # 37 has changed a bit...... bigmouth that.

[mydauphin]

dskira, repost your picture I can't see it.

[Ad Hoc]

I can't see it either...