Re: HP, weight and visability

["Sean Walinga" <swalinga@telusplanet.net>]

Hi Ray,

>1. What is that spacing between the hulls? 3", 6", 12"? You will need access
>   between the hull layers to paint the bare metal or your hull will rust.
>   One option is to make the outer hull removible but then you have to 
>   worry about creating an air tight seal when assembled.
I was considering 3". What have others in the group done for the internal? To get it certified, an inner hull is needed so I naturally thought steel...


>2. Welding a dual layered hull is awkward, especially if the spacing is small.
Ok, how about this.  Outer pressure hull with inner support hull at 1" spacing. The space between would not be flooded. The inner hull would be in cylindrical pieces welded together at each support. I think this would work and would increase the simplicity by quite a bit. The other way would be more efficient but much more difficult...   Back to the drawing board!


>3. Pumping water out of an inner hull tank is doable. That is how the big
>   boys work. You will need a pump capible of pumping directly out to sea
>   pressure, have piping rigid enough restand the sea pressure and a shut
>   off valve as close to the seaward side of the piping that you can.
I cringe at the thought of purchasing a pump that is capable of this. The money it must cost...


>4. An alternative to pumping is to create an internal tank that you can feed
>   compressed air into. The air will drive water out. The tank will have to
>   take the pressure and the piping will have to be substantial.
This is a good idea but I am still faced with the construction difficulties of getting the two hulls together...  Maybe I could have the outer hull as (welded) cylindrical pieces and the inner hull as the pressure hull?


>Regards,
>Ray

Thanks Ray,
Sean