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Good morning, Lawrie,
Over all it's a pretty neat looking concept.
The battery pods are what the sub would land on when on
deck with all the weight and stress transferred to the point where the wings
attach to the main hull. If you place a pair of skids running fore and aft
along the bottom of the hull at approximately 5 o'clock and 7 o'clock, this
would relieve the upward stress on the wing attachments. You
would need to shorten the arms of the pods so they don't extend below the level
of the skids. As you mentioned in your reply to Ian, this arrangement
would also allow you to move your drop weights from the wings to the skids which
should significantly lower the center of gravity and improve stability
particularly on the surface. It would also free up room in the wings for
more ballast/buoyancy which would farther increase stability. If you plan
to step on the wings to get from the sub to a dock or boat, you definitely want
adequate buoyancy under your feet. The longer the wings are, the more
leverage your body weight will have to push down on the wings when
transferring.
However if the sub is suspended in the air by chains
during launch and recovery, you still have the issue of downward stress
at the attachment points of the wings due to the weight of the batteries and
everything else attached to the wings. You'll still have some of that same
stress when the sub is in the water although it will be reduced.
Consider moving the battery pods inward and attaching them to
mounts on the hull. This would relieve a lot of the stress on the
wings and could have other benefits as well such as anti-roll.
You mentioned fore and aft oil tanks in the wings for
adjusting trim. Generally you want to keep the buoyancy higher up and
the weight lower down. Some have set the batteries on rails so they could
shift them fore and aft for trim. This would make your battery pods more
complex, but eliminate the need for your oil tanks completely (even more room
for buoyancy in the wings, too).
I'm considering trim-by-battery (mine are in the main hull),
but also considering having the drop weights shift fore and aft.
The other alternative is that I will have lead trim weights in a carriage
within the hull where I can easily add or subtract weights (depending on whether
or not there is a passenger). No matter which of the three I end
up using, I intend to use an electric worm drive (such as on some
garage door openers) to shift the weight fore and aft.
Are you thinking more in terms of launching from the deck of a
tender or from a trailer at a boat ramp?
Thanks for sharing your drawings. Keep it going.
You have me re-thinking something on my primary design.
Cheers,
Jim T
In a message dated 1/22/2011 5:03:32 A.M. Central Standard Time,
lawrie-psubs@environics.com.au writes:
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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