ferro-cement submarine versus conventional concrete

Discussion in 'Boat Design' started by tugboat, Apr 20, 2010.

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  1. apex1

    apex1 Guest

    Amen!
     
  2. DocScience
    Joined: Apr 2010
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    Location: Sydney, Nova Scotia, Canada

    DocScience Wishful builder

    Sub hull shapes

    If tugboat and anyone else is still reading, here is my take on some hull shapes.
    I added a picture, so I hope it shows up.
    I drew the picture in "MicroSoft PAINT" program.
    To show as an example, Hull shape "A" is made up of 8 hull sections.
    Hull shape "C" is the hull made with 2 half hulls.
    Hull shape "D" would be an integral round pipe where the extra reinforcement is not needed.


    Hull shape "B" is stronger then Hull shape "A" ,
    Hull shape "C" is stronger then Hull shape "B" ,
    Hull shape "D" would be the strongest.
    For depth comparable to what "D" is good for, you would need reinforcements like "E", "F", or most likely "G" , depending on the design.

    Does someone have opinions they can mention about my drawing arrangements ?



    Also, can someone tell me how those REP points work ?
    Thankyou.
     

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    Last edited: Apr 28, 2010
  3. tugboat

    tugboat Previous Member

    Lurvio- I was revisiting your post showing the bridge being done- I think i get what your were saying--if you elongated the hull on its transverse axis, - i.e. made the hull a little more oval or oblate spheroid shaped when looking at the cross section then it could have the ballasted portion at the bottom of the sub and save space and add strength..let me mull this over for a few days and come up with a revised design. see if anything comes of it.

    one thing I was wondering--If the design was going to be more surface vessel than diving- i.e. only occasional dives- would the hull need to be designed with more of a raked bow instead of conical? and more like a u-boat than a nuclear design?
     
  4. tugboat

    tugboat Previous Member

    Docscience- thanks for the post - it makes clear what i was intending.
    i did reread the whole thread - Im on the fence with steel vs concrete. but the steel costs and all it just makes so much sense to try it in concrete..but thats my opinion.
     
  5. tugboat

    tugboat Previous Member

    LYndonJ- i knew the military used titanium..i read it somewhere--this is not where but here is the quote from the source:

    WW1 submarines had their hulls built of carbon steel, and could not submerge below 100 meters. High-strength alloyed steel is still the main material for submarines today, with 250-400 meters depth limit, which cannot be exceeded on a military submarine without sacrificing other characteristics. To exceed that limit, a few submarines were built with titanium hulls. Titanium submarines were especially favored by the Soviets, who developed specialized high-strength alloys, built an industry for producing titanium with affordable costs and have several types of titanium submarines. Titanium alloys allow a major increase in depth, but other systems need to be redesigned as well, so test depth was limited to 1000 meters for K-278 Komsomolets, the deepest-diving military submarine. An Alfa class submarine may have successfully operated at 1300 meters, though continuous operation at such depths would be an excessive stress for many submarine systems. Despite its benefits, high costs of titanium construction led to abandonment of titanium submarines idea as the Cold War ended. This contributes to very high cost of modern submarines (for instance, a Virginia class attack submarine costs 2.6 billion dollars, over $200,000 per ton of displacement).
     
  6. Submarine Tom

    Submarine Tom Previous Member

    And God knows, if it's in print it's just got to be true... Right?

    -Tom
     
  7. tugboat

    tugboat Previous Member

    Why not?
     
  8. kerosene
    Joined: Jul 2006
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    kerosene Senior Member

    Kursk?

    Russian, submarine and truth don't fit in one sentence :p


    and I am just teasing - nothing against Russian people. But I do remember the classic communication during the Kursk incident. Kind of like "there has been a fire at Zhernobyl but is all cool now".
     
  9. WestVanHan
    Joined: Aug 2009
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    WestVanHan Not a Senior Member

    How about spending $50 on a few bags of cement and mesh then build a scale model sub maybe 6' long.

    Get some rope,go out on the lake,and keep dropping it down till you see air bubbles from the collapsed model coming up.

    Film and post on youtube.

    Report back,and gloat.
     
  10. tugboat

    tugboat Previous Member

    WestVanHan--great idea-thank you for telling me about looking for bubbles-- i know its elementary and i should have thought of looking for bubbles- but seriously thats one of the most helpful things i have gained from here since i wondered how i was going to know at what depth it imploded or cracked....I actually had been thinking though - to do just what you described.
    in the meantime i may ask more questions on here. i hope to do a drop test around august or september--i broke a freinds car winsheild by accident(dont ask!) so gotta pay for that! and thats not cheap...- and i am still working on my diesel engine--gotta change a transmission and do some research on it..its an old d 318 cat but man has it got some torque!! and it'lll outlast me!-i traded my cat d4600 for it.
    so im preoccupied with that at the moment--but no worries i will do precisely that...and i will post the results, even if it fails... if so--well..that will answer many questions and i will go with steel,
    i guess ill have to try both methods- i.e. both ferro and conventional pressure hulls..thing is it wont be the same as a full sized sub since there are weak points at the viewports fittings and other areas... its also hard to find a deep enough area...i would like to go to 600 ft ideally to test it. then add my safety factor should it survive.
     
  11. Lurvio
    Joined: Jul 2009
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    Lurvio Mad scientist

    If you place your model in a net or canvas bag that keeps all the particles in from wandering away, you'll feel the model getting a lot heavier when it implodes (loses boyancy). A lot more accurate IMO than waiting for bubbles to rise to the surface.

    Lurvio
     
  12. tugboat

    tugboat Previous Member

    Also thanks Lurvio--again i am learning a lot today...maybe ill use both methods...thanks guys!- i actually cant wait! it will be very interesting to see what happens.
     
  13. kerosene
    Joined: Jul 2006
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    kerosene Senior Member

    how do you figure out the right way of scaling the wall thickness in relation to the vessel size. I would think that they don't quite scale in same relation.

    Are you going to test fatigue by dipping it few hundred times?

    Seems fun but I wouldn't trust my life in results from such arbitrary tests.
     
  14. WestVanHan
    Joined: Aug 2009
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    WestVanHan Not a Senior Member


    Thought of that...but at least it's something

    He can spend a ton of money,and have a disaster-or a bit of money and learn something.
     

  15. rwatson
    Joined: Aug 2007
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    Location: Tasmania,Australia

    rwatson Senior Member

    This "submarine yacht" idea has been thrashed around quite a bit, and I have always been a bit cool on the idea of crawling around the dark, dank spaces (especially in untried hull materials). Not what yachting is all about really.

    But over the months (years?) of discusson, a few glimmers of inspiration have started to gel in that dark dank space above my shoulders.

    Stay with me here, but a couple of experienced commentators have raised the very good point that under say, 50ft, its all dark and gloomy and only good for slimy things. There is heaps to see above that mark as every smorkeller will tell you.

    The other point is that the worst part of yachting is the really rough stuff. Everyone hates the over ... say ... 10 ft waves for days on end. Good 'ol Willmer (bless 'im) made a few good points about avoiding rough weather by going under them (a bit like that trimaran Earth Race that went through waves, not over them)

    Now, say the worst weather you expect to get into are ,hmmm, 100 ft waves. To avoid the bumps from them, you dont have to go very far down - say 50-100 ft ?

    What say, Tuggy me 'ol mate, you just aim for a maximum of a hundred feet or so ?

    You will achieve 90% of the value of what non military subs are for, you get to see most of the visible underwater landscape, and you can do trips under bad weather.

    The challenge now is to design a hull that can double as a sub, and still sail (wind is free - remember that) long distances. Maybe collapsible masts like windsurfer, streamlined deck gear etc.

    This also takes away a lot of the problems of wondering if concrete is good enough - I bet most people would be happy to admit that it would'nt be impossible to use concrete to say 100 ft. Hell, some free divers get that far down using flubbery skin.

    That would take a lot of the angst out of the project, and give you the challenge of designing a new style of yacht, that can sail and submerge.

    Just a twist on the topic - might be worth a thought.
     
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