beginner wants to build a boat

Originally Posted by Raggi_Thor

I suppose, in the US, you get in trouble IF something happens to those 50 persons?

Thats what our "friend" did not like to understand.
The technical solution is the second step, the permission to do it, the first.

[Wavewacker]

Well, I thought I was wackingwaves....there was a 40' pontoon boat on ebay, buying something used that meets the need will probably be your best bet. What's the purpose of this yacht/vessel? I would think that even the floating deck above might fit your bill in sections and connect them, but you can't make that as one structure 40' long with any wave action, if half your craft were off the water a flat structure, to me, seems it would buckle under it's own weight...Hmmm, I'm no engineer, but that would be heavy...do you ever want to move it? Are all of these people going to dance or just sit down, sitting down allowing 4' per row, 4 across, that's 40 in 40'. I'd look at the large pontoon boats. Cheers

[Submarine Tom]

50 people with stuff is easily 200 X 50, that's 10 000 pounds or 5 tons of live "ballast"!

Good luck with that.

-Tom

[DougCim]

Originally Posted by Submarine Tom

50 people with stuff is easily 200 X 50, that's 10 000 pounds or 5 tons of live "ballast"!

Good luck with that.

-Tom

It's not impossible.

US rules state a powerboat's max load weight is rated for 1/5th its max displacement. Assuming for a moment that the hull weighs nothing, then it would only take about 9.5 inches of displacement just to support the passenger load capacity (or rather, to support 5X the passenger load capacity of fifty 200-lb people, over a 25' x 40' deck).

Of course the hull most certainly would not weigh nothing--but the boat would need to be much thicker than that to resist bending anyway, I'd guess at least 3-4 feet,,,, and that's just more flotation that would put its rated capacity way under the 20% rule.

This assumes that you insisted on a single-piece platform, and would build a steel/welded barge-type hull. Beyond some point, the plastic barrels aren't going to be practical, in terms of the safety inspection you would need it to pass. .....This I think is what others have hinted at: if you want to put a motor on a cast-iron bathtub and go cruising you can get away with that, but if the boat is big enough for hauling around a lot of passengers, the structural standards get much more picky.

You would need to get some welding education, welding steel is not difficult but it must be done properly because it would be inspected.
And if I were doing this, I would expect to pay a qualified consultant to help with (or create) the design.
You might even find & hire a retired builder to visit once a day for a bit and advise during construction.
But it could be done by a beginner, I would bet.
The shape is very simple, it's just big.
~

[waynep]

Has anyone seen a houseboat 50 feet long by 20 feet wide with pontoons? That's a sizeable party boat. It would need to be constructed in either two or four parts: 2 Parts -10 feet wide by 50 feet long, or 4 parts: 10 feet wide by 25 feet long. This would give 20 sf per person. Sounds like a major project for a first boat. You would definitely need some professional enineering support or a naval architect for sizing structural members with 10,000 pounds or more of live load alone. What if everyone decides to move to one side of the boat for some reason?

[Submarine Tom]

But it's possible.

Right DC?

-Tom

[DougCim]

Originally Posted by Submarine Tom

But it's possible.

Right DC?

-Tom

What these two people built is much more complicated than what you're asking for.
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[Submarine Tom]

DC,

I'm not asking for anything.

What are you talking about?

-Tom

[DougCim]

Originally Posted by Submarine Tom

DC,

I'm not asking for anything.

What are you talking about?

-Tom

Whoops. I thought you were the OP.
~