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Hi Dean. Designing for impact is a good plan. At some point, when the shit
hits the fan, redundant systems are always a good idea.
My little sub has fiberglass fairings to absorb impact, and even if they
are crushed and totally screwed up, the gear underneath is well protected by
tube steel frames. My ballast tanks are 12 gage SS and will take a good hit,
only denting in the process, not punctured. The mounting geometry for the tube
steel frames puts the collision force from any angle into the hull at an obtuse
angle there by deflecting the force over a large area, transferred from the
point of impact into 2 or 3 tubes. The connection points will rely on the shear
strength of the mounting bolts, and even if some bolts are sheared off, the
tube steel frame will stay attached. Batteries and air tanks are
all located inside, except for one extra scuba tank which is located between the
structural frame work and underneath the back fairing. It's very well
protected there. I can't see where an impact could occur in that area. The
through hulls are also located in areas that are well protected.
The most obvious area of impact will be the side motors/dive
planes. I made the mount from 1-1/2 inch diameter stainless bar stock, and
it will take a serious hit to do anything to that. The dive plane itself will be
mounted to the motor mount with brass bolts so a hard hit will break off
the dive plane ( fiberglass) or shear the brass bolts ( 1/4-20 size) long before
the motor mount is damaged.
The bottom of the sub is another obvious place to get a hit. The only thing
on the bottom is a steel shroud. My drop weight is inside the steel shroud,
and should be well protected from any type of collision. All of the
geometry on these frames, etc. is in a triangle shape. Impacts to a triangular
shaped object are transferred and spread out.
All the through hulls have a valve on them right at the hull. If a crash is
hard enough to break something off the sub, what ever is attached to that part
can be valved off. I'm making a back-up system for pretty much every thing on
the sub, believing that redundancy is like insurance. Better to have it and
never use it, than to need it and not have it.
I put my first color coat on that damn fairing I've been working on for
many months. It looks like something from a Batman movie! I'll try to get a
picture up later today.
Frank D. It's only a deal if it's where you want to go. Find your travel deal here. |