Re: [PSUBS-MAILIST] what is the diference k250- k600

["Captain Nemo" <vulcania@hawaii.rr.com>]

Ian Roxborough wrote: "I find it interesting that the end caps are thicker
than the hull.   I had thought that the end cap dome shape would provide
better resistance to pressure than the cylinder body and hence be
constructed of material the same thinkness or even thinner.  Maybe this is
to compensate for the ribs in the hull.  Anybody have any insight into
this?"

Ian,

To provide uniform strength in a sub's elongated cylindrical pressure hull,
elliptical end caps must be thicker than the side walls because they aren't
curved as much.

Convex-curved structures resist external stress via the principle of the
arch.  The flatter the arch, the weaker it is.  An elliptical end cap is
flatter (and weaker) than the circular cross-section of the cylinder it's
attached to; so making the cap thicker is one way to achieve comparable
strength

Another solution is the hemispherical end cap, but companies making them
aren't as common as those making elliptical caps.

Pat