Re: HP, weight and visability

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

Hi Ray,

>An idea I have toyed with is to build a pressure hull complete with internal
>ribbing. Then weld light weight ribbing external to that. To this light weight
>ribbing I would seal and bolt the ballast tank outer shellthus creating a
>double hull configuration that I can take apart for accessing. The air tight
>seal would be accomplished by some kind of caulking compound.
Hmmm...   The ballast tank outer shell would be in the form of half cylinders then? How far would the light ribbing leave the ballast outer shell from the pressure hull? My first thought is to use a hard rubber seal on that light ribbing. As the bolts are tightened, the resulting effect would be the watertight seal. I'm skeptical of the ability of any caulking compound available. The external ribbing would also act as a support for the main pressure hull as well. Sounds like a good idea and it seems maintainable as well. I guess it will have to be in the typical submarine design then? 


>It's the pressure hull that needs to be metal. Whether that's internal or
>not is up to you and your design.
Ok. ABS Certification can happen with only one metal pressure hull then...



What has ANYBODY used for the inside shell? I have asked this a few times to the group but nobody replies! An internal fiberglass shell bolted to the internal hull support ribs would work I think but am I reinventing the wheel? If no one knows then ideas would even be welcomed.