Re: [PSUBS-MAILIST] concrete submarine - i did it back in 1994 - worked perfectly

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

Hi Wilfried, welcome here ! 

please can we have some pictures of the sub at Moki file - or direkt
send to Ray ? 

How do you build in the pipe, vale  and cable conections - do you build
everything in during the molding process  - or later ? 

Do you build a negative mold to get a smooth outside hull ? 

Hatches also from concret ? 

How fast is the sub - underwater and on the surface - range ? 
- 9 m long  - it is diesel-electric ? 

best regards Carsten


diagroto@ibague.cetcol.net.co schrieb:
> 
> Hello,
> 
> I am Wilfried Ellmer and i recently did a search engine search on my name and
> found it connected to a discussion on this board about concrete submarine
> hulls.
> This explains why i answer now to a discussion that took place here some 3
> years ago.
> 
> One of the questions asked was "did everyone a hull or sub like this" .
> 
> Yes i did one (in 1994) it was: 9 m long 2.5 meter diameter 18cm wall
> thickness, form of a blimp 15 tons wihtout ballast 20tons with ballast.
> 
> I also did earlier a smaller hull of 2m long and 0.7 m diameter to test the
> concept.
> 
> Both hulls where converted in fully functioal subs and i personally had a lot
> of dives and fun in those two subs.
> 
> Fact that i am still writing proves the validity of concept.
> 
> Unfortunatly the concept was so new back in 1994 that i could not find anyone
> interested to discuss or make a projekt with me.
> 
> So let me answer from practikal point of view some questions that came up here:
> 
> Can you transport a hull like this?
> 
> Yes i transported the 9m hull on a truck from innsbruck where i built it to
> lake Atter where i dived with it (some 5 hours) did not break, not leak, no
> damage.
> it was stapled on wood - no special transport thing - impacts that occur on a
> truck will not affect a hull like this.
> 
> Will it crack when you hammer on it ?
> 
> This hull had a 18 cm thick concrete walls curved in 3 dimensions - and
> reinforced by 5mm steel bar net all 5 cm - this is similar to a bunker wall,
> or to a bridge - if you hammer it will it break ? - of course not.
> 
> Will it stand hydrostatic pressure ?
> 
> Just think of hoover dam, or submarine tunnels, or oil drilling platforms, -
> is concrete standing hydrostatic pressure ? - of course for many decades
> without any notable change.
> 
> Do you need non steel reinforcement?
> 
> - no in a 5cm or more thickness concret wall steel bars are perfectly
> protected.
> 
> Will it stand changing load from waves ?
> Is concret standing changing load on bridges - of course ! - and in by far
> more sever conditions. Or in buildings under erver changing wind pressure.
> 
> Is building the hull a tecnical problem ?
> 
> handling a 18cm thick ship hull is always a problem - just imagine welding
> steel plates of 18cm !!! - or forming them as a sphere or streamlined blimp.
> (with 3 dimensional curves). I could do it in a backyard with concrete,
> (without having bubbles and having reinforcement where it belongs) - i doubt
> that i could weld or form 18cm steel plates or alu in a backyard.
> This is a task that is only (if ever) handled in battleship construction.
> What you can do with concrete is incredible strong thick walls on relative
> small subs - this has nothing to do with ferrocemnt as used in yachting (iron
> mashing and plastering on) - this is forming concrete in the way as it is used
> in tunnels or in radio towers with continous forming that makes a little part
> every day.
> Had patented some of this stuff...
> 
> Do you need a special covering - double hull etc:
> 
> No - just use what is proved in tunnel or dam building it will work excellent
> in hydrostatic pressure for decades as it does in dams and tunnels.
> 
> Do it only work for big subs ?
> No - had done 2m sub with 5cm wall thickness and 9m sub with 18cm wall
> thickness both worked excellent.
> 
> How can you test concrete ?
> 
> How do they test dams or bridges or tunnels - x raying every cm? , by using
> paleontolgy equipment? (as a discussion suggests) ?
> 
> I had a practical approach deep test at 150m (was deepest site i could find in
> the lake) and considered it save therefore to dive with 50m.
> 
> If you get obvious material changes over time (rusting of steel reinforcement)
> visible (new) cracks etc...yust do pressure test again and keep it 1/3 in
> normal use this should be save.
> (by the way...did not get any rusting, or cracks during 15 years of use) - So
> is it done in dams, bridges, pressure vessels, concrete pressure hulls of
> nuclear plants etc. - periodic testing with overload - new testing if doubths
> about structural integrity come up at visual inspection.
> 
> No need to predict destruction depth exactly with complicated
> methodes...doesn't work anyhow - not even for navy steel hulls - as example of
> treasure accident shows.
> 
> A wall thickness of 18cm on a 9m boat gives you a calculated destruction depth
> far below 1000m (normal concrete without any special) you can keep it so far
> above that in normal dive operations that it will be save - no matter - if
> anything like bubbles or cracks gives you a little additional weakness.
> All concrete on all dams, tunnels buildings, drill islands etc. have bubbles
> and cracks - do they collaps ? - of course not!
> 
> What is the real problem of constructing a sub or habitat with concrete ?
> 
> Shipyards are not familiar with this material, and those who are familiar with
> it (tunnel engineers) do not build ships or subs.
> 
> Are there unsolved problems?
> 
> All problems are solved for decades all is available but nobody applies it on
> subs.
> I did it - it worked excellent - had a lot of fun -
> 
> If anyone wants to discuss or suggest me a project...please go on.
> 
> Wilfried Ellmer