[PSUBS-MAILIST] Drawing of my 2-man sub

Thu Feb 19 10:28:14 EST 2015

Emile

My FEA analysis shows that you are right, I have already upgraded the
nozzle thickness.

Anders

Thanks for good advice. Don`t have the room for a diesel. Would be fun
to have a look on your sub, it`s not a long drive from Norway.

2015-02-19 11:48 GMT+01.00, Anders Ljung via Personal_Submersibles
<personal_submersibles at psubs.org>:
> Hello
>
> I built and operated the submarine Malen and used it in the baltic sea.
> This boat was 10 tons and 10.5 meters long and had some 1+ meter freeboard.
> Still there where times when i got alot of the baltic sea in my head when
> driving surfaced. High freeboard is esential if operating in open sea.
> I would also recomend some kind of combustion engine onboard if operating
> in the sea , to battle waves and current some 2-3 kw per ton is nice to
> have
> A small marine diesel is a fantastic resource to have onboard plus its more
> fun and ads to the design challenge. If operating in the sea the boat will
> run the best
> with main ballast tanks mounted fore and aft according to my experiance.
> However these are my personal opinions and they might be completly wrong :)
>
> Anders Ljung
>
> 2015-02-02 21:55 GMT+01:00 André Eriksen <personal_submersibles at psubs.org>:
>
>> Thank you for the input Alec.
>>
>> I got a quote some time ago on the hemispheres.. around 1800 USD for the
>> both.
>>
>> Have had the concern of distorted visibility with the acrylic dome, but
>> thought it would be allright since I never have heard complaints on it. I
>> might look into going with a taller tower and flat viewports. More
>> freeboard and better visibility quality is not a bad thing. My center of
>> gravity and bouyancy calculations show I have some flexibilty there.
>>
>> André
>>
>>
>>
>> 2015-01-31 14:43 GMT+01:00 hank pronk via Personal_Submersibles <
>> personal_submersibles at psubs.org>:
>>
>>> Andre,
>>> I have a sub with an acrylic cylinder for the CT and the visibility is
>>> fantastic,
>>> Hank
>>> --------------------------------------------
>>> On Fri, 1/30/15, Alec Smyth via Personal_Submersibles <
>>> personal_submersibles at psubs.org> wrote:
>>>
>>>  Subject: Re: [PSUBS-MAILIST] Drawing of my 2-man sub
>>>  To: "Personal Submersibles General Discussion" <
>>> personal_submersibles at psubs.org>
>>>  Received: Friday, January 30, 2015, 10:27 PM
>>>
>>>  Hi
>>>  Andre,
>>>  Very nice drawing and
>>>  concept, I like the simplicity and it looks balanced. I
>>>  would have the following observations:
>>>  - Check that you can actually get
>>>  those hemispherical heads for a reasonable price.
>>>  Hemispherical heads are far less common than elliptical. I
>>>  was once shopping for endcaps and got the following quote:
>>>  "The elliptical is $300, the hemispherical is $300 plus
>>>  $4000 in tooling setup costs".
>>>  - Regarding the coning tower design
>>>  (K250 in this case) it depends what you want the sub for.
>>>  The problem with that tower is the low freeboard, which is
>>>  fine for lakes but insufficient for open water. You cannot
>>>  open a K250 hatch in the ocean in anything but flat calm
>>>  conditions. Also, visibility out of a K250 dome hatch is not
>>>  good, even though that might sound counter-intuitive. You
>>>  are looking through the side of a dome, which means poor
>>>  optics. The bow dome visibility will be wonderful, because
>>>  you're looking through the apex. Or, of course,
>>>  visibility of the surface will be good from the
>>>  coning tower, but one only uses that upon
>>>  surfacing.
>>>  - I would
>>>  not worry too much about the boat being top heavy. In
>>>  general, between low drop weights, low batteries, and high
>>>  MBTs these little boats are extremely stable. You should be
>>>  able to carry a significantly taller tower than that one
>>>  given the hull beneath it. I'm not saying you should
>>>  skip the stability calculations, I'm just saying I think
>>>  you will find that the calculations prove you can carry a
>>>  higher tower that will allow for flat viewports and increase
>>>  freeboard. Another option is to put a cylindrical viewport
>>>  on the K250 tower to bump it up. I haven't done that
>>>  myself, but it could be done.
>>>  Best,
>>>  Alec
>>>  On Fri, Jan 30, 2015 at
>>>  11:42 AM, André Eriksen <personal_submersibles at psubs.org>
>>>  wrote:
>>>  Hi
>>>  guys!
>>>  Finally I can
>>>  start building. Just rented a nice location outside town.
>>>  This is the drawing of the sub. I want to have 400meters
>>>  (1300ft) of max operating depth. The hull is 10mm
>>>  (3/8") S355J2 steel. The ABS hull calculator is giving
>>>  me 431,8m (1417ft) of depth, and 638,4m (2094ft) crush
>>>  depth. Still have som FEA to do. Have to learn to use a new
>>>  software since Autodesk Inventor don`t simulate buckling.
>>>  Any thoughts on the design?Do someone want to
>>>  confirm my calculations?Very excited to get
>>>  started!Sorry for the metric dimensions for you
>>>  who are not custom to them.
>>>  I had a hard time figuring out the
>>>  conning tower. I wanted it to go in one piece, but I want
>>>  all the freeboard I can get and not get it too top heavy.
>>>  Was thinking about going 20mm thick nozzle all the way up,
>>>  but thinking I might get in trouble welding in the hatch
>>>  seat ring. With 30mm I could do without welding in a seat
>>>  ring, but it would be too top heavy. So decided to go with
>>>  the Kittredge design, any thoughts on this?
>>>  Domes in top and front and saddle
>>>  tanks.
>>>  Emile:
>>>  If you still want to press domes for me, can you give me the
>>>  exact measurements I should have for the bow
>>>  ring?
>>>  -André
>>>
>>>
>>>
>>>
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>>
>>
>>
>> --
>> Med Vennlig Hilsen / Regards
>> *André Eriksen*
>>
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>

-- 
Med Vennlig Hilsen / Regards
*André Eriksen*