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Re: [PSUBS-MAILIST] kitredge sub
Bruno,
A sub has to displace it's weight in water to be neutral buoyant - bit
heavier and it dives, a bit lighter and it floats. No matter how you alter
it, with more steel or more buoyant foam of what ever, that's how it works.
Not complicated!
When a sub is designed properly both it's surface stability and it submerged
stability are designed in by the weight distribution throughout the sub.
The problem with taking an existing hull design and just building it with
thicker steel is that your adding weight to the hull that must be
compensated for by reducing the weight somewhere else. The most obvious
place to reduce weight is reduce things like ballast weight in the BOTTOM of
the hull and maybe even lighten your drop weights.
Now remember the weight you added by thickening the hull is EVENLY
distributed throughout the sub hull. To make matters worse, you'll need to
add more steel to the conning tower up top to strengthen it as well. See
where this is going? You end up moving the overall weight of the hull
(center of gravity) to high in the hull and the sub becomes unstable in the
water. Even worse when floating with the conning tower up out of the water.
There is more to it then just adding steel.
Hope this helps, Dan H.
----- Original Message -----
From: "bruno masse" <rodin4@videotron.ca>
To: <personal_submersibles@psubs.org>
Sent: Thursday, October 09, 2003 8:08 AM
Subject: Re: [PSUBS-MAILIST] kitredge sub
> ok but what about the delta sub that can go to 1200' feet and have litle
> buoyancy?
> ----- Original Message -----
> From: Adam Lawrence <adteleka@in-tch.com>
> To: <personal_submersibles@psubs.org>
> Sent: Thursday, October 09, 2003 12:14 AM
> Subject: Re: [PSUBS-MAILIST] kitredge sub
>
>
> > There comes a point in sub design where the weight of the pressure hull
> > exceeds the buoyant force acting on it. So instead of adding weight to
get
> > your sub to submerge, you have to displace more water with something
> lighter
> > than water. All the subs (I think) built by this
> > group do not reach depths where this transition takes place. After this
> > point, the sub requires some positive ballast dedicated to only
providing
> a
> > buoyant
> > force. Alvin is an example, having a picture of its buoyancy package
shown
> > in Busby (pg. 298). Trieste is the best example, having to carry a
29,000
> > gallons of gasoline, just to keep it afloat. So these subs are basically
> > anchors, connected to an ~incompressible balloon. You can use the Alec's
> > program to
> > find this point.
> > Adam
> >
> > ----- Original Message -----
> > From: "bruno masse" <rodin4@videotron.ca>
> > To: <personal_submersibles@psubs.org>
> > Sent: Wednesday, October 08, 2003 7:40 PM
> > Subject: Re: [PSUBS-MAILIST] kitredge sub
> >
> >
> > > i think that if the hull weight more you need less additional weight!
> > > and why the k-600 is going to be less stable than the k-350 if the
> weight
> > > is at the right place?
> > > ----- Original Message -----
> > > From: Dan H. <JMachine@adelphia.net>
> > > To: <personal_submersibles@psubs.org>
> > > Sent: Wednesday, October 08, 2003 8:18 PM
> > > Subject: Re: [PSUBS-MAILIST] kitredge sub
> > >
> > >
> > > > Another thing to keep in mind is, as you beef up the sub, your
adding
> > > weight
> > > > to it. You can only add so much steel and still have a sub. Beyond
> > that,
> > > > you got an anchor!
> > > >
> > > > The K-350 needs about 500 pounds additional weight placed in the
hull
> to
> > > > dive. The way a K-350 is designed, keeping the batteries and
weights
> > low
> > > on
> > > > the sub, it's stable. If you add steel to the hull over all, you
have
> > to
> > > > lesson the weights in the bottom of the hull. The K-600 does this
at
> > the
> > > > expense of stability. You can only go so far doing this though.
> > > >
> > > > On page 17 in the Busby book, Manned Submersibles, explains in
greater
> > > > detail .
> > > >
> > > > Dan H.
> > > > ----- Original Message -----
> > > > From: "Ian Roxborough" <irox@ix.netcom.com>
> > > > To: <personal_submersibles@psubs.org>
> > > > Sent: Wednesday, October 08, 2003 11:28 AM
> > > > Subject: Re: [PSUBS-MAILIST] kitredge sub
> > > >
> > > >
> > > > > On Wed, 08 Oct 2003 10:32:36 -0400
> > > > > bruno masse <rodin4@videotron.ca> wrote:
> > > > >
> > > > > > another question.
> > > > > > it is about the kitredge sub
> > > > > > my question is: the k-600 have a 3/8" hull thickness and 1/2
thick
> > end
> > > > cap
> > > > > > and can go to 600' feets.
> > > > > > a hull with 1/2 thickness and a end cap with 5/8 to 3/4
thickness
> > can
> > > go
> > > > about
> > > > > > 1000' feets! i my wrong?
> > > > > > somebody can help me with this question please!
> > > > > > thank you
> > > > >
> > > > > In your hull with 1/2 thickness that goes to 1000feet,
> > > > > they are two thinks which you would have to take
> > > > > into account when comparing dive depths. Hull diameter
> > > > > will play a big part in making these calculations.
> > > > > Safety Margin is the other big factor when operational
> > > > > depths are being placed on hulls. Of course they are some
> > > > > other biggies as well, like material, what are the hulls
> > > > > made of? framing? hull length? hull length between
> > > > > heavy framing? how round is the cylinder?
> > > > >
> > > > > Assuming that material, diameter, framing, etc. are the
> > > > > same for the both hulls:
> > > > > The K600 can go a lot deeper than 600feet, I would guess
> > > > > that the theoretical crush depth of such a sub would be
> > > > > in the range of 2 or 3x the operational depth. Can the 1/2 inch
> > > > > thick hull go to 3000feet? Or is a 1000feet it's theoretical
> > > > > limit/clush depth for this hull.
> > > > >
> > > > > I remember reading/hearing about a K250 that was tested
> > > > > to distruction in a pressure tank. If I remember correctly,
> > > > > only the dome on the top failed, at around 3 times the
> > > > > operational depth ~700feet (please, somebody correct me if
> > > > > I'm wrong).
> > > > >
> > > > > The short version of this is:
> > > > > The K-class subs are serious over engineered (and I think
> > > > > this is very good thing).
> > > > >
> > > > > Ian.
> > > > >
> > > >
> > > >
> > > >
> > >
> >
>
>
>