Re: [PSUBS-MAILIST] Radical Idea

[Dan h <machine@epix.net>]

BluWtrSailr@aol.com wrote:

> Ping, Ping, psubers detected...
>
> First, let me say that I will not put a fork in my eye nor shall I allow
> anyone else to do it. He he.
>
> I believe very strongly that the universal language is mathematics and
> everything in the universe is pure mathematics. So, I will make every effort
> to relate everything involved to established mathematical theories and
> formulas.  I hope that this is not an error on my part.  I don't rely too
> much on the fudge factor.

Using a bit of fudge factor for ADDED safety never hurts, but I agree, you can't
fudge your way through a safe and efficient design.  Having a strong math
background is definitely an asset for designing a sub.  For a PSUB, good  hands
on skills don't hurt either.

> A 2 man, 16 foot sub.  A pod of appropriate size to float with its payload
> plus the displacement and payload of the sub. The framing will be 2.5 x 3
> pipe, 1/4" wall.  One pipe will run down the center line of the sole,
> longitudinally, from stern to bow, and will form a rocker at the bow.  Think
> of it as the spine of a boat, or a keel, and the bow will not be endcapped
> but much more like the bow of a boat without the sharp connection, way more
> rounded.
> The framing for the deck of the sub will be the same dimensions, running in
> the same direction, but there will be two frame members instead,  about a
> foot apart and they will connect to the rocker at the bow and will form an
> upside down u at the stern and connect to the sole frame about 5 feet from
> the stern thereby creating a "box" for an aft cockpit, which will be self
> draining and can be occupied when submerged or not.

I may not have the picture correct yet, but I'm imagining two basic boat hulls
one flipped over the top of the other as a mirror image.  Am I at least close?
Sorry, but you lost me totally with the self draining part.  I understand how it
works in surface craft.   Are you proposing the same for your sub?
Are you designing your sub as an ambient pressure sub or a one atmosphere sub?
Wet or dry sub?  You mentioned compressor top side but I'm not sure why.

> This sub will be suspended by a 30' cable (that is the depth I am designing
> the sub for), which will be attached to a winch on a pod.  The sub will be
> "snorkel type" and will have all air hoses, ballast and breathing, wires and
> control switches from pod to sub.  In other words, compressor, generator,
> solar panel, batteries, gasoline,  and all other mechanicals will be in the
> pod above (except for steering and such) and all controls will be in the sub
> below.  The system will be redundant and the sub will be able to rise if all
> or any failures occur at the pod.  Is a matter of fact, the sub will be able
> to rise even if all tanks are full.  The cable will be there only to control
> depth and will not be used to "pull" the sub up , only suspend it, and will
> be winched in when the sub is to be attached to the pod by a "trailer" bar.
> Can I call it that?

Sounds interesting.  The pod concept has been done before but your going deeper
than the one I saw and your designing bigger too.  I don't quite understand how
your sub could be able to rise even if all tanks were flooded and you had an
equipment failure.  Are you dumping emergency ballast?  If your hanging on a
cable you have to be negative buoyant.  Even if you holding yourself down with
thrusters, they usually don't have to power to bring you back up if your ballast
tanks are totally flooded.  I'm probably missing something here too.
Since your using cables you might try to design something to keep them from
hanging slack so they don't foul your thrusters.  At thirty feet, you can always
bail out if you had to, but why not design to avoid the mess.
Are you using your floating pod to double as an over the road trailer too?  That
has real appeal for a lake sub and should be doable.

> The sub will have 4 trolling motors attached as will the pod to maximize
> keeping the pod and the sub lined up when submerged and for greater turning
> whether linear or on its axis.

Keeping the sub and the pod in line and going in the same direction sounds like a
real challenge.  I can think of a few possibilities to do this, but none of them
low tech.  Do you have a plan in mind yet?

> The sub will also have a motorcycle engine
> which will propell the sub when the pod is attached to the back of the sub to
> run on the water.  A removable fuel line will be attached to the sub from the
> pod when the sub is not submerged so that fuel can be fed to the MC engine.

If you design your pod so your sub is within it while surfaced, you can keep you
motorcycle engine topside.   Use the pod to contain your sub and also to lift it
high enough out of the water so you can open a hatch to get out with out getting
swamped.  Your topside pod should be more of a raft with a hole in it rather than
a trailer to your sub.  Pilot the pod to your diving destination with a simple
outboard motor.  No need to have a motorcycle engine other than for a
compressor.  You might rethink the compressor also.  Scuba tanks go a long way
and far less complications.

> The only hazardous material on the sub will be human.
> Now the skin.  Back to the frame.  The frame pipe being square will have a
> groove ground out along its exterior for its entire length at a width of the
> designed skin thickness of the sub.  This groove will allow me to take
> 4x8x1/16 sheets of metal (which will be cut to desired length) and insert
> them into the top and lower groove in layers, like LAMINATING, until the
> required thickness is obtained, which will make the handling and welding of
> material much simpler and will produce a sort of horizontal elliptical shape
> for the sub (cross section).  This shape will be continuous from stern to
> bow, except by the bow where it will be more rounder and the stern which will
> be more square by the cockpit.  OF COURSE, EVERYTHING WILL BE WELDED AND THE
> SOLE PLATE, DECK PLATE AND ANY FLAT SECTION WILL BE THICKER THAN ROUNDED
> SECTIONS. Yes, I plan to reinforce in the interior every x feet, by also
> laminating to required thickness.

I don't agree with your steel laminated skin design at all, unless your laminated
material is laminated to become one, like in the case with a fiberglass and resin
lay up.  Steel doesn't work very well that way.  You can't glue the surfaces
together and than  do any welding on them because you will cook the glue bond.
Two layers of material, one laid flat against the other, are never the strength
of one solid piece if there is no lateral bond.  Think of a leaf spring on an
truck.  You would get much better strength out of one material thickness.  Yes,
it is harder to bend thick material than many thin sheets, even if you compare
bending the thin sheets all at the same time.  Exactly my point!
Also, there's the rust factor.  No matter how you try, water will find it's way
between sheets of steel.

I think I understand your gouging out the pipe to lay in the skin.  I guess you
could do this but, is it really necessary? That's a heck of a lot of grinding and
all just to eliminate the weld bump?

One last thought, remember, if you design is a dry sub, one atmosphere, you
should to be designing a collapse depth of near eighty feet to dive it at
thirty.  You'll want to test the hull unmanned to at least fifty feet.  If your
squeamish as I am, maybe more.  Design your sub so you can stay calm watching it
disappear into the deep blue for it's unmanned test while your thinking of all
the time and money you have hanging on the end of the line.

>
> Okay, there it is.  Actually, it's more complex than this but I figure this
> is enough for the minds of this group to analyze and feed back.  I welcome
> all suggestions and criticism and appreciate if everyone would help me to
> keep the fork out of my eye.
> Anybody think its radically correct and dooable?

It's definitely do able.  You have a great idea over all if it fits what your
needs for a PSUB.  Me on the other hand, I'm building a PSUB and don't really
know what I'm going ot do with it.  So who am I to discuss end use?  :-)
Run some calculations on your hull design first and get that ironed out, both for
shape and your laminated plate idea.  They're the only real hazards I see if I
have the proper mental picture.  There are others in here that can guide you far
more than I.

Good luck, Dan H.

> Hopefully, with enough feed
> back and help, I will put the plans on the board real soon and make them
> available to the group for scrutiny and personal use if they desire...free of
> charge of course.  Questions? Comments? Critisism (Ahem, constructive
> please)? Limitations?
>
> Capt. Charles