Lawrie & Ian,
I like your comments on the drop weight better than
mine. Let the skids just be the skids and place the drop weights between
them at the center.
JT
In a message dated 1/22/2011 8:41:07 A.M. Central Standard Time,
irox@ix.netcom.com writes:
Hi
Lawie,
thanks for the extra information.
I think your thoughts
on moving the drop weights below the main hull along the center are
correct. This will lower the center of gravity and increase the
righting force that they provide. In fact, moving all the
heavy/negatively buoyant components (batteries, drop weights, static
weights, etc.) to as close to the center and as low down as possible would
be a good idea.
Are the vertical fins at the rear controllable
rudders? If so, maybe consider moving them to aft of the thruster,
this will allow you to maneuver at lower speeds.
Using a spreadsheet
is probably quicker/cheaper way of calculating the displacement, weights
and balances rather than building a model. Building a model is a good idea,
but maybe do a few iterations in a spreadsheet first. You can easily
calculate the weights and volumes of the components. Then assign each
component an x,y,z value with 0,0,0 being approximately the center of the
sub and calculate the center of gravity, center of buoyancy and moments at
various pitch and roll angles (with and without the drop weights attached
to make sure it doesn't float upside down after the drop weights
have been released.
Good
luck! Cheers, Ian.
-----Original Message----- >From:
lawrie-psubs@environics.com.au >Sent: Jan 22, 2011 3:02 AM >To:
personal_submersibles@psubs.org >Subject: Re: [PSUBS-MAILIST] K350
salvage concept > >Hi Ian, > >Thanks for the comments
and suggestions. > >I will try and answer a few of the
questions. > >The dimensions are K350, however I changed the
conning tower to accept a >dome. > >The wings are to provide
a lot more bounancy for both salt water and >fresh, given you may wish
to bring something up from the sea bed. > >Once I get to doing the
CAD on the internals, the idea I have for shift >balance fore and aft is
two pairs of oil tanks, one in each wing to ajust >weight using an oil
pump. > >Drop weights within the wings running longitudinal. They
are not detailed, >however thinking it may be better to have one weight
mounted below the main >pressure vessel at center. > >The
two forward motors do rotate, and the tunnel section is to allow >thrust
in the horizontal to assist the rudder at slow speed. I throught >about
bring the wing further in, however I felt it would an advantage
in >terms of tieing off against a boat. In other words, so that
the out part >of the wing protects the forward motors as well as bumping
up against a sub >sea wall port and starboard. > >The
battery pods are much longer than the K350, and I haven't worked
out >the lift accuracy. The estimate is about 75 kgs each wing to
give a lift >of 150 kgs. This is above that required to get the water
line about 100 mm >below the deck line so that the viewport is
sufficiently above the water >line. > >The design has one
main motor for primary thrust, and the end caps are >conventional,
however the drawing shows the fairing to make the center >section more
streamline. > >Its a little futuristic longing, but I figure why
build an ugle looking >boat. > >My next step after more cad
is to build a 1/4 model to work out actual >displacement and where the
weight needs to be disturbuted. You may notice >the batter pods are a
little to aft where the wing sections are thickness. > >The wing
sections are their deepest are about 400 mm. > >There are other
concept drawings, but I really like this one because at >the heart of
the vessel is tried and true K350 pressure hull. > >More drawings
posting soon. > >I really appreciate any help and the
comments. > >Best regards, Lawrie.
> > > > > >On Sat, 22 Jan 2011 05:19:41
-0500 (EST), irox <irox@ix.netcom.com> wrote: >> Hi
Lawie, >> >> nice drawings! >> >> This
looks like a K-250 rather than a K-350 (going by the dome). >> Two
things which would be very useful for understanding the >> design
changes would be a general layout sketch (i.e. ballast >> tanks,
operator positions, drop weights, batteries, etc..) and >> a
description/write-up of the changes and features. >>
>> But here are my comments just based on what I see in
the >> concept drawings. >> >> - Drop
weights? The K-350 had two 250lb drop weights, >>
I don't see any on the drawings. >> >> - How much
soft ballast? Assuming the pontoons are soft >>
ballast tanks, how much lift do they provide? >> >> -
I assume the VBT inside the hull, like a K-250? >> >>
- Can the side thrusters be rotated to provide vertical thrust? >>
>> - Maybe moving the battery pods (assuming they are battery
pods) >> closer together would provide better surface
handling/stability. >> >> - Where do the air tanks
go? >> >> - I am not sure the "winglettes" are doing
much other than >> disrupting the thrust from the side
thrusters. >> >> Cheers! >> Ian. >>
>> -----Original Message----- >>>From:
lawrie-psubs@environics.com.au >>>Sent: Jan 21, 2011 10:51
PM >>>To: personal_submersibles@psubs.org >>>Subject:
[PSUBS-MAILIST] K350 salvage
concept >>> >>> >>> >>>Hi all,
>>> >>>With things a little quiet with the local
floods, I have had >>>some time at night to work on a concept
using the standard K350 pressure >>>vessel.
>>> >>>I hope you like. Comments, critisms, and
improvement suggestions >>>welcomed. I am going to kept working on
this particular concept. >>> >>>What
do >>>you think?
>>> >>>http://www.psubs.org/projects/1280105118/k350-salvage/
[1] >>> >>> >>>Best regards,
Lawrie. >>> >>>Links: >>>------ >>>[1] >>>http://www.psubs.org/projects/1280105118/k350-salvage/ >>
>> >> >> >>
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