Catamaran idea

Perhaps a little explanation?
The lower picture would be a terrible hull.

 

The idea is to use those large propane tanks as hulls for a catamaran. I think they would be good and strong but not sure how they would preform in the water.

 

T0 get low drag you need a low entry angle, a point hull. Your tanks are very blunt
See
Entry Angle. What is the explanation? https://www.boatdesign.net/threads/entry-angle-what-is-the-explanation.21010/

 

Terrible idea. look at typical cat hulls.
Those are fat, short and blunt.
That means lots of drag, terrible wave making (lots of drag), won't turn easily, will come to a stop each time you hit a big wave, and you will have heavy hulls which have to be reinforced if you try to use the inside for storage/ accommodations.

 

I'm noticing that cat hulls are narrow as well as pointed. My guess is that they can be because they're are two of them. I think they're basically pontoons except for being open on top. Not sure how heavy a propane tank would be as compared to something like a fiber glass over wood hull which to me looks very heavy. I suppose the ends could be removed from the tanks and they could be crushed in to form more of an oval shape some way or other. Maybe with an excavator bucket for instance. At that point cat style bows would need to be fabricated and welded to the ends which I think could be done. Another idea is to have an outboard on the end of each hull for accessibility as opposed to cramming engines into the hulls. I don't care if the hulls are closed up pontoons, it's just one more thing keeping it from ever sinking.

 

How many of these tanks do you have ? One issue that comes to mind, is cutting into these old tanks, ( without even thinking about welding) if they contain even a trace of gas, you could find yourself being blown into next week.

 

Yeah ... this. I seem to recall some time ago hearing about how dangerous that sort of activity it.

 

You can't just cut them if you do you have to fill them with water or some inert gas. It's been done with car exhaust , I prefer filling them with water. Not sure the idea would work though, cat hulls have a certain shape to them.