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

[hank pronk via Personal_Submersibles]

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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