|
In a message dated 10/31/2009 2:10:53 P.M. Pacific Standard Time,
lanceind@earthlink.net writes:
To determine a safe dive depth I would have an engineer with pressure vessel experience look at it for you. Good advice Dan.
On the stiffeners being where the 6 inch center ring is.....Sorry,
don't agree. I've cut big holes in the heads seriously reducing
the inherent "dome" strength. To stiffen the hull I'll be using 1/2 inch X
4 inch stiffener pieces cut to fit the inside curvature. They will attach to the
hatch ring which protrudes down into the sub 4 inches and carry down along the
hull interior to the "grid" pattern of floor stiffeners. Yes, a little like the
ribs on a pumpkin.
The floor "grid" serves a couple of purposes. Obviously to stiffen the
bottom, but also to make a solid base where all the vertical stiffeners will
meet. Also the "pockets" created by the floor grid will hold the lead ballast
bricks which will be poured into shapes to match each pocket.
The weakest place on the hull is of course around the windows. Additional
stiffeners will be installed there.
I haven't finalized the stiffener design yet, but basically I'll be getting
some professional help with this to determine how close the vertical stiffeners
need to be, and what type of cross bracing it needs.
I may find that adding some extra reinforcing is required around the window
and hatch holes. Much like the early K boats, where a big piece of steel
equal to the amount cut out for the tower was added to the tower/hull connection
perimeter. That was a standard method used by tank builders when a hole was cut
in.
Again, a serious professional FEA study will be required to obtain a safe
operating depth.
Thanks for the advice. All thoughts and critisism are welcome.
Frank D.
|