<div dir="ltr"><div><div><div><div><div><div><div>Hello<br><br></div>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. <br></div>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.<br></div>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<br></div>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<br></div>with main ballast tanks mounted fore and aft according to my experiance.<br></div>However these are my personal opinions and they might be completly wrong :)<br><br></div>Anders Ljung<br></div><div class="gmail_extra"><br><div class="gmail_quote">2015-02-02 21:55 GMT+01:00 André Eriksen <span dir="ltr"><<a href="mailto:personal_submersibles@psubs.org" target="_blank">personal_submersibles@psubs.org</a>></span>:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><div dir="ltr">Thank you for the input Alec. <div><br></div><div>I got a quote some time ago on the hemispheres.. around 1800 USD for the both.</div><div><br></div><div>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.</div><div><br></div><div>André</div><div><br></div><div><br></div></div><div class="gmail_extra"><div><div class="h5"><br><div class="gmail_quote">2015-01-31 14:43 GMT+01:00 hank pronk via Personal_Submersibles <span dir="ltr"><<a href="mailto:personal_submersibles@psubs.org" target="_blank">personal_submersibles@psubs.org</a>></span>:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">Andre,<br>
I have a sub with an acrylic cylinder for the CT and the visibility is fantastic,<br>
Hank<br>
--------------------------------------------<br>
On Fri, 1/30/15, Alec Smyth via Personal_Submersibles <<a href="mailto:personal_submersibles@psubs.org" target="_blank">personal_submersibles@psubs.org</a>> wrote:<br>
<br>
Subject: Re: [PSUBS-MAILIST] Drawing of my 2-man sub<br>
To: "Personal Submersibles General Discussion" <<a href="mailto:personal_submersibles@psubs.org" target="_blank">personal_submersibles@psubs.org</a>><br>
Received: Friday, January 30, 2015, 10:27 PM<br>
<div><div><br>
Hi<br>
Andre,<br>
Very nice drawing and<br>
concept, I like the simplicity and it looks balanced. I<br>
would have the following observations:<br>
- Check that you can actually get<br>
those hemispherical heads for a reasonable price.<br>
Hemispherical heads are far less common than elliptical. I<br>
was once shopping for endcaps and got the following quote:<br>
"The elliptical is $300, the hemispherical is $300 plus<br>
$4000 in tooling setup costs".<br>
- Regarding the coning tower design<br>
(K250 in this case) it depends what you want the sub for.<br>
The problem with that tower is the low freeboard, which is<br>
fine for lakes but insufficient for open water. You cannot<br>
open a K250 hatch in the ocean in anything but flat calm<br>
conditions. Also, visibility out of a K250 dome hatch is not<br>
good, even though that might sound counter-intuitive. You<br>
are looking through the side of a dome, which means poor<br>
optics. The bow dome visibility will be wonderful, because<br>
you're looking through the apex. Or, of course,<br>
visibility of the surface will be good from the<br>
coning tower, but one only uses that upon<br>
surfacing.<br>
- I would<br>
not worry too much about the boat being top heavy. In<br>
general, between low drop weights, low batteries, and high<br>
MBTs these little boats are extremely stable. You should be<br>
able to carry a significantly taller tower than that one<br>
given the hull beneath it. I'm not saying you should<br>
skip the stability calculations, I'm just saying I think<br>
you will find that the calculations prove you can carry a<br>
higher tower that will allow for flat viewports and increase<br>
freeboard. Another option is to put a cylindrical viewport<br>
on the K250 tower to bump it up. I haven't done that<br>
myself, but it could be done.<br>
Best,<br>
Alec <br>
On Fri, Jan 30, 2015 at<br>
11:42 AM, André Eriksen <<a href="mailto:personal_submersibles@psubs.org" target="_blank">personal_submersibles@psubs.org</a>><br>
wrote:<br>
Hi<br>
guys!<br>
Finally I can<br>
start building. Just rented a nice location outside town.<br>
This is the drawing of the sub. I want to have 400meters<br>
(1300ft) of max operating depth. The hull is 10mm<br>
(3/8") S355J2 steel. The ABS hull calculator is giving<br>
me 431,8m (1417ft) of depth, and 638,4m (2094ft) crush<br>
depth. Still have som FEA to do. Have to learn to use a new<br>
software since Autodesk Inventor don`t simulate buckling.<br>
</div></div> Any thoughts on the design?Do someone want to<br>
<span> confirm my calculations?Very excited to get<br>
</span> started!Sorry for the metric dimensions for you<br>
<span> who are not custom to them.<br>
I had a hard time figuring out the<br>
conning tower. I wanted it to go in one piece, but I want<br>
all the freeboard I can get and not get it too top heavy.<br>
Was thinking about going 20mm thick nozzle all the way up,<br>
but thinking I might get in trouble welding in the hatch<br>
seat ring. With 30mm I could do without welding in a seat<br>
ring, but it would be too top heavy. So decided to go with<br>
the Kittredge design, any thoughts on this? <br>
Domes in top and front and saddle<br>
tanks.<br>
Emile:<br>
If you still want to press domes for me, can you give me the<br>
exact measurements I should have for the bow<br>
ring?<br>
-André<br>
<br>
<br>
<br>
<br>
</span><span> _______________________________________________<br>
<br>
Personal_Submersibles mailing list<br>
<br>
<a href="mailto:Personal_Submersibles@psubs.org" target="_blank">Personal_Submersibles@psubs.org</a><br>
<br>
<a href="http://www.psubs.org/mailman/listinfo.cgi/personal_submersibles" target="_blank">http://www.psubs.org/mailman/listinfo.cgi/personal_submersibles</a><br>
<br>
<br>
<br>
<br>
</span> -----Inline Attachment Follows-----<br>
<div><div><br>
_______________________________________________<br>
Personal_Submersibles mailing list<br>
<a href="mailto:Personal_Submersibles@psubs.org" target="_blank">Personal_Submersibles@psubs.org</a><br>
<a href="http://www.psubs.org/mailman/listinfo.cgi/personal_submersibles" target="_blank">http://www.psubs.org/mailman/listinfo.cgi/personal_submersibles</a><br>
<br>
<br>
_______________________________________________<br>
Personal_Submersibles mailing list<br>
<a href="mailto:Personal_Submersibles@psubs.org" target="_blank">Personal_Submersibles@psubs.org</a><br>
<a href="http://www.psubs.org/mailman/listinfo.cgi/personal_submersibles" target="_blank">http://www.psubs.org/mailman/listinfo.cgi/personal_submersibles</a><br>
</div></div></blockquote></div><br><br clear="all"><div><br></div></div></div><span class="HOEnZb"><font color="#888888">-- <br><div><div dir="ltr"><div><font face="arial black,sans-serif">Med Vennlig Hilsen / Regards</font></div><div><font face="arial black,sans-serif"><em>André Eriksen</em></font></div></div></div>
</font></span></div>
<br>_______________________________________________<br>
Personal_Submersibles mailing list<br>
<a href="mailto:Personal_Submersibles@psubs.org">Personal_Submersibles@psubs.org</a><br>
<a href="http://www.psubs.org/mailman/listinfo.cgi/personal_submersibles" target="_blank">http://www.psubs.org/mailman/listinfo.cgi/personal_submersibles</a><br>
<br></blockquote></div><br></div>