Let's talk about concrete submarines

(Larry G) #1

@ellmer has built a couple of them. It’s an impressive accomplishment.

There are some excellent qualities to such a structure. The materials are reasonable cost. Concrete’s biggest strength is in compression, and the torpedo like shape is mostly self-buttressing (spheres are the ultimate self-buttressing shape, but cylinders come close and are a more usable interior for practical purposes).

Recent knowledge advances in Geopolymer and Basalt FRTP rebar may make it an even better structure due to better water/salt resistance.

What about construction techniques? I have never seen any good description of how the things were built. What is the difficulty level for

-the hobbyist
-the third world shipyard
-the industrial world shipyard

What tools, equipment, and facilities are needed?

Othe topics-

Submarines are great when they are below the waves, but only nuclear powered submarines can submerge for more than a few hours. On the surface, submarines have a reputation for being miserable wallowing pigs.

People don’t thrive in tight enclosed environments. Naval submariners are carefully chosen for exceptional tolerance for the environment, and despite spending months at a time, don’t live in submarines and must rotate out at intervals. How does this relate to a seastead that is normally submerged?

Granting the engineering benefits to a torpedo shape, how does that actually relate to a practical seastead?

Granting that concrete cylinders are great in co press ion, how many duty cycles of compression and expansion does concrete have in it before failure.

Does the concrete sub equalize pressure or rely upon structure to resist crush? If equalizing pressure, there are a whole slew of other hysiological issues to overcome.

Submarines don’t allow the crew to interact with their environment the way ships do, they just insulate crew from the environment. How does that advance living and making a living at sea? Other than a very few, very limited tour subs, submarines are currently only in major use for austere exploration and austere military purposes. There aren’t any recreational live aboard family subs in common production I am aware of.

All of the arguments against ships as seasteads seem vastly magnified when it comes to submerged structures and vessels, unless they are fixed to a shallow bottom and open to the top.

(Wilfried Ellmer) #2

@thebastidge | Larry, at the oceanic business alliance we have a strong “due participant only politics” we talk topics like engineering, finance, and similar, only with people we consider qualified, and we keep that talks in dedicated boardrooms.

So if you want us to “let some of the info goodies about our projects out here, on this public forum”, you first need to convince us that at least some of your forum users are capeable to have the kind of conversation that is of interest for our projects.

For now i am a bit reserved given the history (last 8 years) of these threads.

But i am always open to give you a chance to convince me otherwise - so go ahead and give it a try…

Kindest Regards

Wilfried Ellmer

For those who are interested in crush depth analysis, they will find useful (and already pubished) info here.

For those who are interested in basalt rebar and advanced cement composite solutions for ocean colonization the info is here.

For those who are interested in a realistc picture how submerged living space looks like, and want info from an expert, who has actually been there and done that, - check here. I opened this thread specifically to correct all kind of “absurd theories” and “perception errors”.

For those who are interrested in the technological connections between our concrete submarines and the building of New Venice and New Atlantis check here.

(Bob LLewellyn) #3

The traditional submarine was designed to travel through the water at great depths. A submergable home would only need to move up and down, and not more than a hundred feet. The cylinder shape is a knee jerk reaction because all sub are cylindrical. I don’t remember the actual numbers but from memory a standard 12 in wall (box type) would withstand the pressure at 100’. Maybe it was a yard (1 meter).
Flood-able air chambers on the sides would be enough to raise and lower the sea home. However, making the actual sea home is not part of the Marinea Project. We intend to sell for others and take orders for other builders.

Let’s say Will shows me several plans that he and his team can build and have delivered to Marinea. I get back with him and ask if he could change X,Y,Z to make the structure more marketable. He can change some but can’t change all because of stability issues. We put the designs on our website and begin to market those designs. We add a stipulation that the sea homes have to remain in Marinea until completely paid and I think we can add financing availability.

So when I say submarine, I may have a different vision than everyone else. I see the property as floating on the surface, large enough to be stable in normal waters. The yard space would be the top deck and the living quarters would be below. The reason for this is that cement passes heat ridiculously well. Any structure on the Sal Bank area will have a lot of sun. Those cement houses will become ovens in short duration. By putting the home below the wave or partially so, we limit the amount of direct sun hitting it and since cement passes heat well, the wall dropping into the water will act as a heat sink. It will still be hot but adding a roof over the top deck will give plenty of room for solar-cells and act as a catch basin for rain water.

When the home needs to duck out of foul weather, you close the air intakes and close the entry hatch and sink her to the bottom. After the waves subside, she is re-floated. So is that version a cement submarine?

For the concrete, I would argue to use volcanic ash (the Roman formula) as it swells to seal the interior from the saltwater, lasts at least 2,000 years.


Actually, the cylindrical and spherical shapes of the pressure hulls are designed to resist the pressures they encounter, which is why they are called “pressure hulls”. A sphere distributes pressure better.

At 100 ft of depth, that hull is at approximately 44.5 psi, plus or minus .445 psi per foot of structure below, or above that mark.

Pressure hulls are rated at roughly 1/2 the theoretical crush depth, based off the materials used.

Flexing cement hulls with significant pressure changes will introduce micro fractures, just as flexing ferrocement boats with wave action does.

Another drawback is the extreme difficulty adhering additional cement, whether patching, or adding to the structure. This is a well known problem, so monolithic cement structures built of one continuous pour are going to be the preferred method of construction.

(Larry G) closed #5
