Tuesday, January 1, 2008

Concrete Submarine Hull

This Blog is dedicated to discuss concrete submarine pressure hulls.

Concrete Submarine Pressure Hulls

Concrete submarine pressure hulls in marine environment in use today - proved for decades...
To give anybody who is interested in concrete submarine yacht construction a clear idea what is the status of modern concrete construction in marine ambient i put a couple of photos together to make my point clear that a concrete submarine yacht hull is not a highly experimental issue - In contrary - submarine concrete hulls are in use today all over the world - just in other fields of engineering...

So- please guys do not ask any longer questions like: "can concrete float?", "will concrete melt away in saltwater ?", "Will a concrete submarine have cracks and let water trough like a sponge? - just relax and think about the fact why the guys that build the things shown below sleep very well and trust concrete as mankinds most used and tested building material.

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.


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.

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...


forum manager said...

This is where tunnel engineers, civil engineers and others familiar with concrete as a pressure hull building material can share experience with us...especally about things "naval engineers" are not so familiar with...

Guillermo, Naval Engineer, said...

Guillermo, Naval Engineer, Question on ( http://boatdesign.net ) - Interesting project, Wil. But it's going to be no easy task. Have you compared costs against an all steel one? Cheers.

wil said...

Hello Guillermo, I agree that in yacht building steel is the better option. - Not so in a submarine.
Walls of a 9m sub as my prototype are 18 cm thick and have spheric curves - no way to do this in steel. While you go for al light hull in a yacht you go for a pressure resistant hull in a sub. This is where advantage of making thick walls with little forming effort becomes important.

Second, steel needs maintainance, concrete not. This is why oil rig legs and submarine tunnels are made in concrete not in steel. You could not take a platform like troll out of the water every season to get new paint on it and even less a submarine tunnel. - With a light steel yacht you can. Even a small sub like my project is a lot more heavier than a similiar sized surface boat - therefore slipping cost is high - so avoiding go to slip during decades is a mayor cost benefit.

My submarine yacht had lower maintainance cost than similar sized sailing yachts under same mooring conditions. see (http://concretesubmarine.com) - This was because it never needed to be taken out of water during a decade - and due to the lack of deck and lines and sails that can be damaged by weather and UV rays.
What concerns cost, just sandblasting and painting a steel hull will be more expensive than building a concrete hull.
The steel hull for Euronaut had the following cost: 16 m x 2,5m x 22mm in 2002 for 50.000 euro about 64500 USD - the boat has a displacement of 70 tons which means hull cost of about 714 euro per ton of displacement - for a 2,2cm thick hull. In concrete you get 331 Euro/ton of displacement in a 20cm thick hull (almost 10 times thicker than a steel hull) free of maintainance cost formed to elegant blimp shape.