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

["Brian Cox" <ojaibees@ojai.net>]

Hi Wilfried,   Never heard answer to Carsten's question about how you accomplished your ballast systems , were they built into the sub when it was poured?

Brian Cox
----- Original Message ----- 
From: <diagroto@ibague.cetcol.net.co>
To: <Personal_Submersibles@psubs.org>
Sent: Sunday, September 28, 2003 11:54 AM
Subject: [PSUBS-MAILIST] concrete submarine - i did it back in 1994 - worked perfectly


> 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
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