Easy to build

I love it , but dont know nothing about it . Bolger did know somthing about this stuff. It might be good to read what he has written, as well a study his
box keel designs. But good luck, he knew alot about it , but can no long tell us anything. Atkin, as mentioned above, knew a few things about this box keel.
Can you interpret his designs ?

In both case these men had many years of experimentation to work it out .

Can you reinvent the wheel in the time you have?

Maybe.

 

Ok. Thanks everybodyl for all advice. I will go for another desig, absolutly!
Any suggestions for a something easybuild in steel ?, se my earlier post for details.

 

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Tomac

Please keep us posted with your designs....'cause I too am interested in sth similar to your requirements.



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Hi
I have made som googling for Bolger, according Frank:s post, very interesting boatdesigner, lot of designs with sligtly curved flat bottom. Of curse i dont know anything about how the work. Some revievs are really positive.

http://hallman.org/bolger/isometrics.html

There is some sharpies and skiffs with really flat bottom.
One of them, the Cabin Clam skiff looks kind of similar with my first post.

What is your opinius about Bolgers vessels? Are they effective in inshore waters?

 

I agree, a simple sharpie type hull will suit your purpose, and its easy to build.

 

The Cabin Clam Skiff, isn't even close to your design for several, mostly obvious reasons. First off, the clam skiff is a plane mode vessel, not displacement. If you can't see the reasons your deign isn't much like the Bolger Clam Skiff, you should just put down your mouse and start studying yacht design.

Design software doesn't design anything. It's just offers up wire frame models of you inputs. If you don't know why you do certain things, it'll will blindly obey you commands, regardless of how well suited the lines may be to your needs. Simply put, it's not going to tell you if you designed a boat poorly matched to you needs. This is where yacht design fundamentals come to play.

Build a Tennessee (another Bolger design). It's simple, efficient and can be converted to metal construction (read more studying). Designing all but a small pram or dinghy requires a number of skills, which you haven't acquired yet. This isn't to say you will not, but at best you've mastered pretty picture making, which is a far cry from yacht design skills, that will permit you to venture farther from shore, then you can swim back to, with some level of success. I'm not trying to insult you, but the design above that you've posted, has so many flaws, it's just begging to be criticized. There's no useful result in this, but to hopefully get you to study hydrodynamic principles, rather then play with software who's dynamics, you clearly haven't any understanding of.

 

Thanks for the advice. I is very true, I have no knowledge what so ever i shipdesig, thats why i try to learn from forum like this with a lot of skilled naval experts.
I very well understand that my proposed design post after all comments is a complete flaw and now buried forever.

I am very greateful for the tips from PAR and Groper , I will certainly go with a proven design like this.

The Bolger Tennessee looks to be a almost perfect match for my requirements. Of course i had to learn a lot lot more of the design before starting the project.

One more question, Is there any extra concerns for pounding with a flat bottom 10m sharpie when hitting bigger waves from e.g another larger boats?

 

You only want to do 9 kts yes? So No, you dont have to worry about pounding...

What you have to worry about now is the scantlings and stiffening of the hull... These Bolger type hulls have very little inherent stiffness due to the very flat panels. So if you indeed build, you will need to allow for many stringers...

Have you considered how you will determine your frame and stringer spacing?
Have you calculated the weight using your desired material ie 3mm steel?

My personal guesstimate is that 3mm steel will be too heavy for this to work well... the boat will be very heavy which will ruin its efficiency...

 

Hi Groper

Thanks for the answers and remarks concerning the structual, I´st worth a lot with expericense like yours for a rookie like me.

Now I really like this Bolger T design more and more.

I will first do weight calculations for 3 mm steel, mabye it will be to heavy
with all stringers, reinforecement etc. I will come back with my ruff estimated calculation.

I hav to study efficient distance for the stringers further. Mabye it´s comes to L-profiles 40X40x3-4mm and c-c 400-500 mm as i have seen i other vessel. That will for shore put on a lot of weight. I really don´t know yet.

I have a lot to learn and study in this project.

 

Groper, you`ve been right, it will be way to heavy compare to the design i found on the net. The desig has to be adapted to steel as PAR said.

Mabye i have to give up toughts forr steel, even considering future fuel efficience.

I made one one-off smaller craft in plywood and plastic years ago. It´s quit simple but i rellay dislike the smell and all the sticky mess around with epoxi and polyester. Also the sanding is not so nice with fine dust (despite vaccum) everywhere.

 

Tennessee wouldn't do well as a steel build, without some displacement modifications, though aluminum is possible and I think there's a few done this way. A steel Tennessee will lose some of it's efficiency to beam and draft increases, but she'll still be trim enough to do quite well.

I couldn't disagree more with this comment. The design is more than adequate for the conditions it was expected to encounter. It's a displacement craft and some movement is expected, but not an unnecessary amount. Built to plan she's just fine. If converted, she'll need some thought, depending on the method and build envisioned, but not unreasonable.

 

PAR, If I still going for a steel hull, is there any webbsite to visit for more information about Tennessee steel build just for a short brief to see how a dicplacement modifications is possible. I have tryed to surf but no result.

I wery much like the concept and the looks of this design.

If it shows that a steel modification is too complicated then i have to go back to plywood and reinforced plastic. Aluminium is i belive way to expensive for me.

 

I don't know of any Tennessee builds in steel. It would need considerable modification, not only in displacement and volume distribution, but also construction method. For your uses and considering your experience level, you'd be best advised to just stick with the plans and it's recommend build type. If you wanted a steel design, because of some welding skills, then you'll need to contact a designer or NA and have a conversion preformed, as it's not something a novice can do, and feel safe about it in a storm.

 

http://www.thomasecolvin.com/sharpies.htm

These hulls were designed to be built from steel from the start. Might not suit the OP's needs, I don't know, but if he wants a steel boat, looking at these designs is a good starting place.

PDW

 

Have a look at the selection of craft offered by the designers/architects on this forum. You'll find many to meet or exceed your requirements. The fact that they give freely of their time advising in successful outcomes of other's designs, is a strong indication of guidance and help with their own.

P.S. Look long and hard at your choice of steel-- while economical for larger vessels in the long run it is not the most economical nor the best material structurally often resulting in poor dynamic characteristics in smaller vessels.

A yacht is not determined by the vessel but by the care and love of it's owner---