Concrete submarine

Discussion in 'All Things Boats & Boating' started by waterchopper, Sep 24, 2008.

Thread Status:
Not open for further replies.
  1. wellmer
    Joined: Sep 2006
    Posts: 76
    Likes: 5, Points: 0, Legacy Rep: -64
    Location: Colombia

    wellmer New Member

    concrete or steel submarine yacht - what is better

    For finding an anwer to the question what is better - you need to define what are you looking for. What makes concrete the best option for a civil submarine yacht project is simply you get "most BANG for the BUG". In other words you get a giant hull that is surprisingly pressure resistant, comfortable, and maintainance free, at moderate cost.

    Wil
     
  2. wellmer
    Joined: Sep 2006
    Posts: 76
    Likes: 5, Points: 0, Legacy Rep: -64
    Location: Colombia

    wellmer New Member

    scraping a submarine hull

    a concrete hull will be fine with the same level of maintainance that have submarine tunnels oil rigs, bridge foundations, to keep it barnacle free you have to scrap them off. What is different to a wood, or steel hull is that the material needs no attention at all. No sandblasting, painting, drydock. - once in water it can stay there for several decades. This is a major cost saver - imagine TROLL A platform going to drydock for sandblasting and repainting every 2 years...

    The hydrodynamic slik hull is a "can have" - you scrubb frequently or put a antifouling - but i also envision a green minded submarine yacht owner who likes BEN FRANKLIN style drift voyages and welcomes marine life on his hull. You might see your submarine yacht as the center of a floating marine community - you can do that in concrete -

    wil
     
  3. BillyDoc
    Joined: May 2005
    Posts: 420
    Likes: 18, Points: 0, Legacy Rep: 266
    Location: Pensacola, Florida

    BillyDoc Senior Member

    Wellmer,

    Wouldn't fiber reinforcement be better than steel rebar? Here in the US you can get a bag of fibers mixed in your concrete for about $1/ cubic yard and, according to the guy I saw doing it, eliminate the rebar completely. I think the fibers he was using were polypropylene, but I'm not sure. This was several years ago, but I liked the idea a lot! No possibility of rust that way, and a nice thick matrix of randomly oriented tensile reinforcement as a result.

    Am I mis-remembering something here?

    BillyDoc
     
  4. Tcubed
    Joined: Sep 2008
    Posts: 435
    Likes: 18, Points: 0, Legacy Rep: 318
    Location: French Guyana

    Tcubed Boat Designer

    If this is the option the navy is researching, i would think it would be difficult to distinguish the sub from any other random rock....(?)
     
  5. wellmer
    Joined: Sep 2006
    Posts: 76
    Likes: 5, Points: 0, Legacy Rep: -64
    Location: Colombia

    wellmer New Member

    Hello Billy Doc

    Intersting field - i am aware that concrete compression strength can be increased about a factor 10 over normal concrete, and lot of stuff is possible with rebar replacement. At the moment i am going for a yacht type sub with shallow dive - the hulls i have in mind have a estimated destruction depth of some 1200m this is way more than you would need for submarine yachting.
    Anyhow i discussed with carsten from the euronaut project a deep diver that could go to some 3700m and reach average ocean bottom special concrete could come handy in such a project - i will look closer to that if i have funding for such a project.

    We where discussing the vacuum infusion thing if i recall it right...

    Cheers,
    Wil
     
  6. wellmer
    Joined: Sep 2006
    Posts: 76
    Likes: 5, Points: 0, Legacy Rep: -64
    Location: Colombia

    wellmer New Member

    No i see no chance to come to 11 000m in near future with a concrete sub. But i have plans (still lack funding) for average ocean bottom depth...

    Cheers Wil
    concretesubmarine.com
     
  7. wellmer
    Joined: Sep 2006
    Posts: 76
    Likes: 5, Points: 0, Legacy Rep: -64
    Location: Colombia

    wellmer New Member

    Hello Tug,
    A good size for a fixed snorkel is a similar proportion as the male orca fin. Would be some 4m for a 20m sub. If you plan a extra long snorkel you might be better with a not compressible hose. Telescopic sounds complicated.
    Cheers,
    Wil
     
  8. wellmer
    Joined: Sep 2006
    Posts: 76
    Likes: 5, Points: 0, Legacy Rep: -64
    Location: Colombia

    wellmer New Member

    You are the adviser that recommended his navy NOT to go into concrete subs... do i recall that right?

    Cheers,
    Wil
     
  9. wellmer
    Joined: Sep 2006
    Posts: 76
    Likes: 5, Points: 0, Legacy Rep: -64
    Location: Colombia

    wellmer New Member

    Of course you can drill concrete - easier than steel.
    Reliable thru hulls - never had a problem ...
    Never had a drama with a hatch.
    Steel and concrete have very similar expansion rates this makes steelbars in concrete as a compound material possible.
    I am not aware that submarine concrete projects like eurotunnel, Troll A, etc use concrete for lame *** money saving - very particular point of view.
    Structural concrete engineering has 2000 years of tradition going back to ancient rome ...
    The blimp shape is because it is the BEST shape and you can form concrete to ANY shape and thickness which is not the case in steel.
    No rocking on anchor place - not my submarine yachts.
    Concrete is the most quality controlled and controllable material in the engineering world.
    Yes you trust concrete every time you enter a building with thousands of tons of pressure in the columns and changing wind loads all the time.
    On of the BIG advantage of concrete is that it gives clear visible warning before weakening by rust brings up failure - any civil engineer can orient you on that..

    Cheers,
    Wil
     
  10. Jimbo1490
    Joined: Jun 2005
    Posts: 784
    Likes: 41, Points: 0, Legacy Rep: 527
    Location: Orlando, FL

    Jimbo1490 Senior Member

    I think one thing the some posters are forgetting with respect to concrete is that there are a whole range of off-the-shelf specialty epoxy bonding agents designed specifically for permanently bonding concrete. These are engineered to have superior adhesion and very similar Cte to concrete, so obtaining a reliable bond of a close-fitting steel tube to a hole drilled in a concrete shell should pose no problem at all.

    Jimbo
     
  11. wellmer
    Joined: Sep 2006
    Posts: 76
    Likes: 5, Points: 0, Legacy Rep: -64
    Location: Colombia

    wellmer New Member

    Hello Jimbo, thanks for this very informed comment. Putting a steel tube into a concrete wall is easy - you can do it with epoxy as you describe, you can do it by just forming it in, you can use fast curing fixation cement... The whole discussion of difficulties in connections is a discussion that is valid for thin ferro cement hulls where it is a real problem as you have only a few millimeter of concrete thickness. The hull thickness of the concrete submarine yacht i am currently building is 34cm. You can drill in any concrete screw and it will hold. A epoxy fixation of 34 cm lenght as you describe will hold any doomsday event tension and pressure forces that destroy the tubing long before the bonding will break. So the whole connector discussion is a thing imported from another planet (thin walled ferro cement yachts) to a field where it does not really belong (thick walled structural concrete) -
    Cheers,
    Wil
     
  12. wellmer
    Joined: Sep 2006
    Posts: 76
    Likes: 5, Points: 0, Legacy Rep: -64
    Location: Colombia

    wellmer New Member

    Hello Billy Doc,
    What concerns the reinforcement in deep diving concrete structures some research is necessary - it seems that even steel rebar might lower the destruction depth some 10% compared to non reinforced concrete...

    ... it seems that "fibers" that are added to the concrete to increase tension resistance can at the same time lower compression force resistance...

    see:

    Title : Behavior of Steel Bar Reinforced Concrete Spheres under Hydrostatic Loading.

    Descriptive Note : Technical note Jun 71-Oct 73,

    Corporate Author : CIVIL ENGINEERING LAB (NAVY) PORT HUENEME CALIF

    Personal Author(s) : Albertsen,N. D.

    Report Date : APR 1975

    Pagination or Media Count : 27

    Abstract : Four reinforced and two unreinforced concrete spheres of 32.00-inch outside diameter (OD) and 2.71-inch wall thickness (t) were tested under hydrostatic loading to determine the effect of embedded steel reinforcement on structural behavior. Test results show that the reinforced spheres (0.44 or 1.10% steel by area) failed by implosion at values for the ratio of implosion pressure to concrete strength that were on the average 5% lower than for the unreinforced spheres of the same size. In addition, the reinforced spheres developed cracks in-the-plane-of-the-wall at the inner surface of the reinforcement cage prior to implosion. Implosion results for the unreinforced spheres are 10% lower than predicted by an empirical equation developed from previous tests of unreinforced 16-inch OD spheres. These results provide initial insight into the behavior of hydrostatically loaded steel bar reinforced concrete spheres and indicate that additional test data is required before definitive design guides can be developed.

    Descriptors : *UNDERWATER STRUCTURES, *REINFORCED CONCRETE, CRACKS, SPHERES, STEEL, FAILURE(MECHANICS), REINFORCING MATERIALS, HYDROSTATIC PRESSURE.
     
  13. wellmer
    Joined: Sep 2006
    Posts: 76
    Likes: 5, Points: 0, Legacy Rep: -64
    Location: Colombia

    wellmer New Member

    Hello Arildo, here a study about the question at what waterdepth do concrete hulls implode...

    Cheers,
    Wil
    concretesubmarine.com

    EHAVIOR OF SPHERICAL CONCRETE HULLS UNDER HYDROSTATIC LOADING-PART III.


    Relationship Between thickness-To-Diameter Ratio and Critical Pressures, Strains, and Water permeation Rates, Technical Report R588, Naval Civil Engineering laboratory, Port Hueneme, CA, by J.D. Stachiw and K. Mack, June 1968, 36 pages.

    Sixteen hollow concrete spheres of 16-inch outside diameter were subjected to external hydrostatic pressure to investigate the relationship between the sphere's shell thickness and (1) its critical pressure, (2) permeability, and (3) strain magnitude. The shell thickness of the spheres varied from 1 inch to 4 inches in 1-inch steps. All spheres were cast from the same concrete mix, cured under identical temperature and moisture conditions, and tested in the same manner. The strength of concrete in the spheres at the time of testing, as established by uniaxial compression tests on 3 x 6-inch cylinders, was in the 9,000-to-11,000-psi range. The critical pressure of waterproofed hollow concrete spheres was found to be approximately a linear function of the sphere's thickness; the spheres imploded at pressures from 3,240 to 13,900 psi, depending on their thickness. Concrete spheres permeated by seawater failed at hydrostatic pressures 30% to 15% lower than identical waterproofed spheres. In all cases the stress in the spheres at the time of implosion was considerably higher than in concrete test cylinders prepared of the same mix and of the same curing history subjected to uniaxial compression. The resistance of concrete to permeation by seawater into the interior of nonwater proofed spheres at 2,000-psi hydrostatic pressure was found to be an exponential function of shell thickness. The rate of flow into the sphere's interior ranged from 6.1 to 0.197 ml/day/ ft2 of exterior surface, depending on the thickness of shell.

    source
    http://www.hydroports.com/underwater03.htm
     
  14. wellmer
    Joined: Sep 2006
    Posts: 76
    Likes: 5, Points: 0, Legacy Rep: -64
    Location: Colombia

    wellmer New Member

    deep sea concrete structures

    Hello daiquiri;229671

    Yes concrete is a very fine building material for deep ocean structures... no joke about that!

    See the study from NAVAL CIVIL ENGINEERING LAB PORT HUENEME CA and check the conclusion:

    ...Concrete is a durable material in the deep ocean; neither deterioration of the concrete matrix nor corrosion of reinforcing steel are problems, even though the concrete becomes saturated with seawater...

    By the way the guy on top of that concrete submarine is me....
    see.

    concretesubmarine.com

    [​IMG]

    ---------------

    Title : Long-Term, Deep Ocean Test of Concrete Spherical Structures - Results after 13 Years.

    Descriptive Note : Technical rept. Mar 78-Nov 84,

    Corporate Author : NAVAL CIVIL ENGINEERING LAB PORT HUENEME CA

    Personal Author(s) : Rail,R. D. ; Wendt,R. L.

    Report Date : JUL 1985

    Pagination or Media Count : 70

    Abstract : In 1971, a long-term, deep-ocean test was started on 18 pressure-resistant, hollow concrete spheres, 66 inches in outside diameter by 4.12 inches in wall thickness. The spheres were placed in the ocean near the seafloor at depths from 1,840 to 5,075 feet. Over a 13 year period, annual inspections of the spheres using submersibles have provided data on time-dependent failure and permeability. After 5.3 years of exposure, three spheres were retrieved from the ocean for laboratory testing, and after 10.5 years two more spheres were retrieved and tested. This report is the third report in a series describing and summarizing the findings from the ocean and laboratory tests. Data on concrete compressive strength gain, short-term implosion strength of the retrieved spheres, and permeability and durability of the concrete were obtained. The data have shown that concrete exhibits good behavior for ocean applications. High quality, well-cured concrete can be expected to gain and maintain strength when submerged in seawater under high pressure. Concrete is a durable material in the deep ocean; neither deterioration of the concrete matrix nor corrosion of reinforcing steel are problems, even though the concrete becomes saturated with seawater. Uncoated concrete has a very low rate of premeation of seawater through the concrete and even this small flow can be prevented by a waterproofing coating. (Author)

    Descriptors : *CONCRETE, *STRENGTH(MECHANICS), *UNDERWATER STRUCTURES, *DEEP OCEANS, THICKNESS, PERMEABILITY, LABORATORY TESTS, CORROSION, TIME DEPENDENCE, FAILURE, HIGH PRESSURE, SPHERES, DEPTH, STEEL, SHORT RANGE(TIME), COATINGS, STRENGTH(GENERAL), GAIN, INSPECTION, WALLS, FLOW, OCEANS, DETERIORATION, SEA WATER, LOW RATE, OCEAN BOTTOM, REINFORCING MATERIALS, COMPRESSIVE PROPERTIES, WATERPROOFING, SUBMERSIBLES, IMPLOSIONS.

    Subject Categories : PHYSICAL AND DYNAMIC OCEANOGRAPHY
    CERAMICS, REFRACTORIES AND GLASS

    Distribution Statement : APPROVED FOR PUBLIC RELEASE

    source:
    http://oai.dtic.mil/oai/oai?verb=getRecord&metadataPrefix=html&identifier=ADA160232
     

  15. wellmer
    Joined: Sep 2006
    Posts: 76
    Likes: 5, Points: 0, Legacy Rep: -64
    Location: Colombia

    wellmer New Member

    [​IMG]

    This is my concrete sub prototype - a 18m is almost done...
    ------------------

    Here is what navy is doing...

    Corporate Author : CIVIL ENGINEERING LAB (NAVY) PORT HUENEME CA

    Personal Author(s) : Haynes,Harvey H. ; Highberg ,Roy S.

    Report Date : JAN 1979

    Pagination or Media Count : 53

    Abstract : In 1971, a long-term, deep-ocean test was started on eighteen concrete spheres, 66 inches (1, 676 mm) in outside diameter by 4,12 inches (105 mm) in wall thickness. The spheres were placed in the ocean at depths from 1,840 to 5,075 feet (560 to 1,547 m). Over a 6.4-year period, yearly inspections of the spheres by submersibles have provided data on time-depedent failure and permeability. After 5.3 years, three of the spheres were retrieved from the ocean for laboratory testing. Data on concrete compressive strength gain, short-term implosion strength of the three retrieved spheres, and permeability and durability of the concrete were obtained. This report summarizes the findings from the laboratory and ocean tests. (Author)

    Descriptors : *CONCRETE, *UNDERWATER STRUCTURES, PERMEABILITY, PERFORMANCE(ENGINEERING), LOADS(FORCES), SHELLS(STRUCTURAL FORMS), SPHERES, STRENGTH(MECHANICS), LONG RANGE(TIME), SATURATION, PROTECTIVE COATINGS, WALLS, MARINE ENGINEERING, DEEP OCEANS, COMPRESSIVE PROPERTIES, WATERPROOFING, STRUCTURAL ENGINEERING, SEA TESTING, HYDROSTATIC PRESSURE, IMPLOSIONS.

    -----------------

    Descriptive Note : Technical rept. Jun 68-Jul 71,

    Corporate Author : NAVAL CIVIL ENGINEERING LAB PORT HUENEME CALIF

    Personal Author(s) : Haynes,H. H. ; Kahn,L. F.

    Report Date : SEP 1972

    Pagination or Media Count : 93

    Abstract : Fourteen unreinforced concrete and mortar spheres, 66 inches in outside diameter (OD) and 4.125 inches in wall thickness, were subjected to simulated deep-ocean loading conditions. The average short-term implosion pressure for wet-concrete spheres was 2,350 psi and for the dry-concrete spheres was 2,810 psi; the average uniaxial compressive strength of the concrete was respectively 7,810 psi and 9,190 psi. Under long-term loading, the concrete spheres failed by static fatigue where the relation between level of sustained pressure and time to implosion was similar to that known for concrete under uniaxial loading. Wet-concrete spehres under seawater pressure as high as 1.670 psi showed an average D'Arcy's permeability coefficient, K sub c, of 10 to the minus 12 power ft/sec; this K sub c value was also similar to that known for concrete under freqhwater pressure as high as 400 psi. Design guides were developed to predict the short- and long-term implosion pressures and permeability rates of concrete spheres. (Author)

    Descriptors : (*UNDERWATER VEHICLES, HYDROSTATICS), (*SHELLS(STRUCTURAL FORMS), *CONCRETE), (*SPHERES, CONCRETE), COMPRESSIVE PROPERTIES, PRESSURIZATION, LOADS(FORCES), DEFORMATION, STRAIN(MECHANICS), RUPTURE, DEEP WATER

    Subject Categories : MARINE ENGINEERING
    MECHANICS

    -------------------------------

    A Decade of Ocean Testing of Pressure-Resistant Concrete Structures
    Rail, R.
    Naval Civil Engineering Laboratory, Port Hueneme, CA, USA;

    This paper appears in: OCEANS
    Publication Date: Aug 1983
    Volume: 15, On page(s): 593- 597
    Current Version Published: 2003-01-06
    Abstract
    By means of long-term deep-ocean exposure and laboratory testing, experimental data have been obtained on compressive strength behavior, permeability, and durability of pressure-resistant concrete structural models (concrete spheres 66-inch O.D. by 4-1/8-inch wall thickness) subjected to continuously sustained hydrostatic pressure loading. After 10-1/2 years of ocean exposure at water depths of 1,840 to 5,075 feet, the major findings include: (a) The implosion (failure) strength and stiffness of the concrete spheres and the uniaxial compressive strength of concrete specimens increased during the first 5-1/2 years exposure in the ocean and remained essentially constant during the next 5 years; (b) There has been no evidence of seawater permeating through the walls into the interior of ocean-exposed spheres externally coated with a waterproofing material; uncoated (bare concrete) spheres have a very low rate of water ingress, i.e., a permeability coefficient of about10^{-14}ft/ sec; and (c) Visual inspection and microstructure examination of retrieved specimens have not revealed any significant deterioration of the concrete matrix; no corrosion was visible on steel reinforcing bars which had as little as one inch clear cover. This program has been a decade-long demonstration of the effective use of concrete in the ocean; it has been shown that concrete is a durable, reliable material for pressure-resistant structures for long-term deep-ocean applications.
    ------------------------
    looks some navies DO concrete... i do it too...


    [​IMG]

    some civil engineers do it too...



    Image 1

    Statoil's massive concrete based Heidrun platform. The legs of this platform reach over 100m down into the sea. Basicly this floating city is based on the fact that a concrete hull can withstand the ocean pressure stroms and waves all the way from surface to 100m depth during decades - without any alteration.


    Image2

    Inside the concrete leg of a drilling platform. (Troll Platform) Those engineers at the moment of the photo are tecnically "dived at 300 m protected from water pressure by a submarine concrete hull" of collosal dimension that stands vertically instead of horizontally - just flip that platformleg (in your mind) 90 degrees and add a propeller - you have a giant submarine of 24m diameter with 1m wall thickness and 300m length. This is not a new horizon tecnically speaking - it is just to see things from a slightly different angle. By the way my prototype submarine had a wall diameter ratio of almost exactly the double of troll - so it is good for water pressure at 600m including a similar security factor.


    Image3
    Grande Dixence, on the river Dixence in Switzerland, concrete dam. It was built between 1953 and 1961 to a height of 285 m (935 ft). Concrete at the foot of this dam holds a watercolumn of 285m - equivalent of 285m dive depth in a submarine.

    Image 4
    HIBERNIA CANADA, drilling platfrom 105.5m deep diving concrete submarine hull...

    Image 5
    Golf of Corinth Greece, the legs of this bridge go 70m down to the ocean floor. They where built at sea in floating status and do rest on ocean floor with very little force to enable the bridge to move in case of earthquakes - so this bridge is founded on 70m deep dived submarine concrete hulls.

    Image 6
    Seikan Tunnel - This train emerges from the depth of 240 m below the sea of japan where ist was protected during his passage by nothing else than a submarine concrete hull - horizontally in this case...


    Cheers,
    Wil
    concretesubmarine.com:D
     
Loading...
Forum posts represent the experience, opinion, and view of individual users. Boat Design Net does not necessarily endorse nor share the view of each individual post.
When making potentially dangerous or financial decisions, always employ and consult appropriate professionals. Your circumstances or experience may be different.
Thread Status:
Not open for further replies.