Pontoon Boat Design

[SamSam]

Some vague thought in the middle of the night said "Wait a minute, isn't it..." but if that explanation works for now, that floats my boat. It's sort of a strange concept, some people think if you pump air into a pontoon and pressurize it, it will float higher, but no. Another concept, I had a weeklong running argument in '85 with a construction crew I was working with, on how the astronauts practiced weightlessness. They'd seen it on TV, and I happened to hear something about a room so I said "You know how they do it , don't you?" "How?" someone said ( I could hear "Smart ass Yankee" in their smirks) So I explained how they get in a plane and when it takes a steep dive they float because when objects are free falling they are weightless. That set them off. Guffaws , laughs, How stupid did I think they were?, Where'd you come up with that ****?, They got a room down there at NASA with the chairs bolted to the floor, etc. It branched off to the Civil War. The South's gonna rise again! Yea, like a turd in the ocean. Whut about Sherman!? What about Andersonville? Huh? The prison. Whut prison? After a week some said they used that giant spinning machine to do it while others thought they sucked the gravity out of the room. They weren't quite sure how they sucked it out, but it was Somehow. We were building a clinic, finally one hollered to a passing Authority, "Hey Doc, how do they get the gravity out of that room they got down where the astronauts are?" "Well, they don't actually have a room..." and then almost word for word confirmed what I had said. They were stunned speechless. It was sweet, I poked them with that for months. Sam

[kach22i]

SamSam, sounds like you might of been dealing with a 6-pack lunch crowd on top of it all. I love a good contractor but when they don't get something, something they have not done before, and I explain it as best I can in "builder speak" they often laugh. If I try to explain as I would to an engineer or another architect they can get outright hostile right off the bat. As an architect I feel your pain, funny story.

THE SOUTH SHALL RISE!!!!!!!

Just to tease you: What if the Pontoon were filled with a lighter than air gas?

I think the gas would off-set the weight, but be prone to flooding upon below the water line impact just as air would.

[JonathanCole]

Originally Posted by SamSam

No, again. It's not the trapped air in the foam that provides the bouyancy. The size of the piece of foam and the water it displaces is what provides the bouyancy. The trapped air just makes the foam itself lighter. Sam

The lesson - the lighter the displacement vessel, the higher it rides on the water. The higher it rides on the water, the less wetted area and the faster the hull speed.

The aluminum skin of the pontoon will actually bond to poured-in-place urethane foam and give the ultra-light, nearly unsinkable mass of foam protection from some of the more egregious forms of slicing, gouging and cracking. The downside is that after the foam cures, it shrinks a bit and that causes the walls of your aluminum pontoon to collapse, too. No more smooth shiny cylinder. However if you pour a release agent in and rotate the pontoon before you add the liquified urethane foam and hardener mix, then you'll have a foam log inside an aluminum one. You can run some plastic tubing in through the inspection plug so you can pump the pontoon out by pressure or suction if it springs a leak (pressure is better because you can easily find the leak). Then you have a practically unsinkable pontoon.

Of course you could put just enough foam in to fill up to or a bit above the water line to maintain bouyancy. The whole thing does not need to be filled with foam to prevent sinking. To make the thing really rugged, get sheets of HDPE and lay them over the pontoons while heating uniformly. Plastic welding closes any open seams. Since the HDPE shrinks as it cools you get a skin tight fit, meaning you have to leave the top of the pontoon uncovered so that the HDPE sleeve can contract without collapsing the pontoon. Then you get a nearly indestructible, abrasion-proof layer over your aluminum hull. It would be very resistant to punctures and tears. A new form of composite hull!

[safewalrus]

So fill the pontoon with Texas bull***t

"The South Will rise again!"

[SamSam]

Originally Posted by kach22i

SamSam, sounds like you might of been dealing with a 6-pack lunch crowd on top of it all. I love a good contractor but when they don't get something, something they have not done before, and I explain it as best I can in "builder speak" they often laugh. If I try to explain as I would to an engineer or another architect they can get outright hostile right off the bat. As an architect I feel your pain, funny story.

Now I know that if some one tells me "I've been doing this for XX years", the odds are there will be problems. Sam

[kach22i]

Originally Posted by SamSam

Now I know that if some one tells me "I've been doing this for XX years", the odds are there will be problems. Sam

Oh yea that is the other classic disclaimer which is supposed to erase common sense and convince you to follow illogic and the herd.

[Wellydeckhand]

Wow...... gonna change a barge that is laced with foam....... indestructible? will try on small scale first...... thanks.........