# I need book smart help with this boat design.

1. Oct 18, 2012

### parkland

I need "book smart" help with this boat design.

Here is a picture of the design which I will explain in a minute....

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2. Oct 18, 2012

### parkland

Re: I need "book smart" help with this boat design.

OK... first of all, I would like to say I can take criticism, my drawings suck.
Why is this boat design being posted in a forum like this?
Because the shear mechanics of it are mind boggling. haha.

Let me explain the design.
This is my design attempt at creating the largest possible boat, that can be towed behind a regular 1 ton pickup truck.
Legal trailer widths are generally 8 ft 6 in wide, and 40 long or so, that isn't an issue.
Forgive me if my measurements are vague or not exact, they are estimates as the final materials are not chosen yet.

Looking at the drawing;

"d" is the main cabin, and main structure of this unit. I plan to build it very rigid, almost like a giant box beam, all from aluminum bolted together. Also not the "d" would be about 8' wide, 7' tall, and 35 ' long. About the size of a bumper hitch longer camper.
For transporting on highway, "e" would slide down completely over "d", as it is a flimsy structure with transparent tinted plastic only... very light and minimal structure.

So far, this is pretty simple... till the next steps.

Notice the structure (f) under "d", and under the wings (h). This structure, needs to fold up against the decks over it, and also needs to be in 3 sections, as the wings will fold up against the body for transport.

Basically what has to be accomplished, is that we need a number of beams travelling about 24 ft across, to support the cabin weight on the pontoons.
But they need to "unbolt" into 3 beams, then fold flat, to reduce space. (see "b" and "c" )

The folding part of it, not exactly an engineering challenge. In fact, non of this design is really anything special, just a lot of details that need to be addressed.

So I do have a few questions...

How does a person go about calculating beam strength, and structure strength?
There is a weight limit, so I can't just use 24" tall aluminum I beams, they will need to be built from something like 4" angles, and 3" x 1/4" strapping.

The cabin would weigh about 10,000 lbs at the most, so would a safe bet be to design the framework to support 40,000 lbs before being damaged?

I have exhausted reading with boat building information, and it didn't go far, because I'm essentially not building a boat... the pontoons are "off the shelf" pre made aluminum pontoons, so the boat is already taken care of.
What I need, is structural design help for on top of the boat.

Make any sense?