Re: [PSUBS-MAILIST] Hull construction concept: pipes

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

Hi Mike - 

"GST" stands for "gaseous oxygen stored in the toroidal pressure hull"
and is also the explantion for this hull design. I have here
the main data of the project from 1988 the 
gst Midget 100MK1 LWT 27-4 : 

Length overall 		27,10 m
Outside diameter  	 3,14 m 
Standard Displacement	100 ts
Submerged displ.	136 ts
Underwater speed max	18 kn
Underwater sp.transit	 8 kn
Underwater range	1600 nautical miles
Crew space 		12 + 4
Underwater endurance	14 Days
Operation deep	>	200 m 
Armament		4 LW Torpedos

The sub has an two Anerobic diesel engine generators
and a electric main drive. 

I think about this kind of hull : 

1.) Most problem on this design (for a psuber) is the 
amazing quantity of welding each 3 inch of the hull length
- a full both side turn around welding in this example. 

2.) Its nice because you can create any kind of (full axis symetrical)
hull shape with just a pipeprofil-roller machine and a full 
automatic cylinder welder. Rocket style, teardrop style, 
coca-cola bottle style etc.. all the same process.. 

3.) Any kind of hull penetration is more difficult than 
in normal hull design. 

4.) Could be very intresting for a deep diving sandwich 
GRP design..  .. you have not to weld.. 

5.) Maybe better : a pipe ring - than a short cylinder
make from flat steel profil - than pipe ring etc. 

Double hull subs has always problem with rust.. so I have 
no tanks, rooms or even pipes in Sgt.Peppers or in CSSX 
which I can not go in or inspect by hatches. 
In CSSX I can go into the soft tanks and also into the 
Regulator tanks. 

Carsten

"Michael B. Holt" schrieb:
> 
> Look at Stan Zimmerman's "Submarine Technology for the 21st Century."
> He recalls, on page 84, how subs were called "sewer pipes."  That's
> the lead-in to the torodoial hull: a hull made of HY 80 pipe bent
> into a ring.
> 
> The rings are welded together.  They can be used to contain ballast
> or other fluids, of course.   In the first attempt at using it, an
> Italian company built a 29-ton boat called "3GST9."  That first
> number is the diameter in inches of the pipe used to make the
> hull.  It's insured to 430 meters, but the builder thinks it could
> go to 600 meters with no trouble.  No date was given, but from the
> context it must have been built before 1990.
> 
> Has anyone else heard of this?  The designer was G. G. Santi, who
> worked for Maritalia S.p.A., Milan.  Maritalia is bankrupt, it
> seems.
> 
> (I wondered if perhaps the idea might be adapted to create the
> slab-sided hull of a sub from the American Civil War, with
> more security than would be available if flat sheets of steel
> were used.)
> 
> One question I have is about rust.  If the pipes aren't used to contain
> something that would exclude water, would not the submarine be faced
> with a pressure hull that was rusting invisibly?
> 
> Mike