Re: Best Sub Shape

[VBra676539@aol.com]

In a message dated 7/1/99 10:13:09 PM, fphillips5@excite.com writes:

<<Members, Regardless of what the non-pressure skin looks like or what the
material that's used, is it fair to assume the best pressure hull shape is
still the sphere?  F. Phillips>>

That's entirely dependant on your purpose. The sphere is the simplest and 
most efficienct hull form, but not necessarily the best type of hull until 
pressure becomes a primary factor (such as a 2,000 meter operating depth or 
something). Shallow boats can have different shapes and for the psubbers 
uses.  However, a spherical hull is simple, cheap and quick to build. One 
equatorial weld, a few viewports and penetrators and a hatch and you're in 
business.

For example, look at the early Electric Boat sub Star I, which was built for 
fun by two in-house engineers as a personal project (early psubbers?!!!) and 
adopted by the company. It was a 48" sphere with pressure compensated 
batteries mounted in a streamlined tail with trolling motor thrusters and a 
plexi dome as a hatch. 1/4" thick and rated to 200 feet (it would almost 
certainly have gone a good bit deeper). From that design, Ashera, Star II and 
Star III were developed. A psubber could buy a couple of hemisperical heads 
and be in the sub business for $500 or so. It carried two 18-volt battery 
boxes, some surplus WW II air corps oxygen bottles for flotation, and could 
be launched right off the beach off a trailer. In fact, it sounds like 
something right up our alley!

The work boats of the past were cylindrical because we filled them full of 
hardware and ham sandwiches and stuff and hung hundreds of pounds of gear off 
them and carried tons of batteries. Psubbers, for the most part, don't need 
all that stuff. I'd say a small spherical hull in a streamlined outer skin 
was definitely worthy of consideration.

Vance