Re: [PSUBS-MAILIST] Newbee to psubs...

[MerlinSub@t-online.de (Carsten Standfuß)]

Hi John, Carsten here from Germany, my answers between your lines. 

"John R. Farrington" schrieb:
> 
> Hi all,
> 
> Just wanted to take a few moments to introduce myself.
> I've been lurking on the list for a little while, and
> interested in psubs for quite a number of years now.
> 
> I'd exchanged some mail with a guy named Matt Hunsaker
> about 6 years ago and he'd given me some interesting
> info on a sub of his, a Sportsman 300.  That kinda
> got me interested in psubs, but I pretty much shelved
> the idea until now.
> 
> I've been digging through the archives to start becoming
> more familiar with psubs, and to start getting a grasp
> on what is involved in building one.
> 
> I'm in contact with Vance concerning the Kittredge plans
> and now have a few more general questions that I thought
> I'd pose to the group.
> 
> With respect to psub certification:
> 
>   It appears that psub certification is very valuable.
>   Any idea if most psubs that are out there are actually
>   certified, or do most people just do away with having
>   them certified?

During assembling the Sgt.Peppers I bought a Certification book
from the GL (Germanischer Lloyd) with is simillar to ABS. 
The hole sub as is is now without certification had cost 
for material of about 10.000 Dollar. 
The tank test witch is nessesary for certification cost
about 25.000 Dollar a day plus the incurance company for the
navy tank test Chamber also 25.000 Dollar. 
Every vale with a certification mark on it will cost about 2-10 times
the price of one without. 
(I have worked in a factory for brass parts - make the factory test
mark on each 1 of 10 vales - its the same vales like the other without
marks..) 
Certification is useful if you want to insurance your sub, or for
tourist sub, or sub with a commercial crew or commerical operation. 
For private use it is normaly to expensive. 
But buy the book and build the sub according to the rules. 

> 
>   I do have welding experience, but have no license or
>   welding certification of that sort.  If I do my own
>   welding on the pressure hull, is the hull still
>   certifyable if it passes the appropriate depth tests?

No..its not. You need certification for the steel, for the welder,
the electrodes and also xrays testing..

I am also a experince welder without licence - but all pressure
parts (pressure hull) on my sub are made from a professional.
All outside and inside weelding made by myself. It is not so expensive 
it looks like. The pressure hull has normaly not so much welding-areas. 
One longitudinal, two cyles and one or two for the tower. 
For my next sub I will go the same way.. with pressure hull weldings
made from a robot control welding machine.  
> 
>   The sub that I'd be building would likely be of the
>   Kittredge variety, I believe rated to a depth of 250
>   feet.  This means it should be tested to 500 feet or so.
>   I live in Austin TX, which doesn't have any 500 foot
>   deep lakes around.  When others pressure test their
>   subs, do they typically trailer them down to the ocean,
>   hire a boat with some sort of crane/winch mechanism,
>   haul the sub into deep water, then do a number of
>   plunges with the sub to the test depth?
>   (BTW, if anyone owns a sub, and lives in central TX,
>    I'd be interested in seeing the sub in person)

And if you sit/lay inside you will find out why it has flooded..
I did it in this way but never reach test dive - the lakes here
are really shallow..

> 
> The sub that I build would probably do 99% of its
> dives in the local lakes, which usually have a visibility
> of 15-20 feet, or less.  Sometimes 5 feet or less in some
> areas.  Because of the limited visibility, I've got big
> concerns about getting the sub tangled in someone's old
> anchor line, or whatever may be lurking on the bottom.
> 
> Has anyone out there had any serious incidents involving
> entanglement?  Ever had to abandon because of entanglement?
> 

I have not - but it helps if all engines are protected and
inside the streamline hull - without arms , lights, thruister
etc. outside. 
I can drop my both front thruster if a rope is inside 
and also the main battery keel.  

> I'd like to be able to get out of the sub, clear the
> entanglement, and get back in, without having to flood
> the sub.  Anybody have a sub with a hatch on the bottom
> as well as on the top?  ie: Raise the air pressure in
> the sub to ambient, exit with scuba gear, clear the
> entanglement, climb back in, head to surface, bleeding
> off extra pressure on ascent. (keeping in mind all
> nitrogen-related issues)

I have made a drawing concept for this kind of vessel 
with a hutch on the bottom between two drivers. 
But you need a 50 pound anchor or a landing gear and additional 
50 pound in your regulator tanks. If you leave a so small 
sub the inside lost the volume and weight of your body. 
So with your body goes out the same amount of water gets in - or
if you have an automatic to level the waterline in the hutchpipe -
the sub will fly away because of the loss of 40 pounds weight. 
Also some small implosions of all your TV screens and other
close parts..
> 
> A K-250 has an approx. volume of 40 cubic ft from what
> I can tell.  So one full scuba tank would get you
> an additional 2 atm inside the sub, which is about
> 65ft of water.  I'd need 2 full tanks to be able to
> exit the sub at 125 feet, three would get me over
> 180ft, (max lake depth is around 160), but at that
> depth, I don't think I'd really have the time
> (decompression-wise), to fill the sub, get out, clear
> an entanglement, get back in, and get the sub to
> shallow water before taking on too much nitrogen.

You can use helium to fill the sub..
> 
> (sorry for being long-winded)  ;-)
> 
> But maybe at 50ft I could get out and back in.
> 
> The idea is to save the sub, without flooding it.
> Or, are my efforts better spent building the sub such
> that flooding it damages as little as possible?

That is a new - and maybe good idear. Most part of my 
electronic like echosounder, radio etc and also the 
Live Support System will be ready for a scrapp-place
after flooding in salt water. But if you protected all 
this stuff - thats will be maybe more expensive as to buy new one..

In fresh water and with all electronic-platines covered with
clear-painting and the battery main switch offline- maybe that helps. 

I dumped a car in salt water during trailer my motorboat some
years before. I removed it from the water after 5 minutes, lost the
radio two minutes later, cleaned it with high pressure frehwater the
same days, lost the lamps after two days, the servo stearing
contol after two weeks, the starter after 3 and the breaks after 4..
It was not my car..

> 
> I'm still trying to decide if building one of these
> would be worth it, knowing all of the risks, as well
> as knowing that my primary dive opportunities will
> just be in a lake.

Build a boat for at minimum two persons is a good idear.

Carsten

> 
> Sure sounds like fun though!
> 
> Thanks for any advice.
> 
> -John Farrington