My Viva Vivas seastead design


$10k for 5x5x5 m bare hull or turn key?

(noboxes) #49

Well, yes and no. You cannot tow a high capacity ready-to-float roro down the highway, but you can tow the pieces to where you can assemble before launch. Then it’s less interference from locals to just drive your building materials onto the roro and motor out to a second flatdeck barge configured as a floating drydock. Build on the drydock, then lower the drydock, and float off the completed new modules. The seastead will want a floating drydock anyhow, for maintenance of the small stuff. It’s why i suggested using any public ramp as material access to land. Still need a SSB tho, for snail mail etc…

I don’t know where on the pie-shapes the 5x5x5m refers to, but i just priced 1/4in/6mm common steel plate for a 16x16 area in the $2,600 ballpark. If you multiply that by 3.5 to cover three 5x5m exteriors and a bottom, that’s $9,100. Gotchas, bracing, welding rods, paying me, etc, not included.

(Chad Elwartowski) #51

Bare hull.

But I would not be surprised if, with labor and overhead it would end up closer to 3x as much.

(noboxes) #52

Elwar, did you do any stability tests on these pie shapes?

(Chad Elwartowski) #53

I created a computer image and put it on a web forum.

My original plan when I retired was to test the feasibility of this design in Thailand when I retired (renting a place on the water) but after seeing that Blue Frontiers actually has a viable way forward for getting a seastead in the water I abandoned this design and am putting my efforts toward that.

Like I said, I just wanted to get the video into this thread since I had done a lot more work on it and I wanted it all in one place before the forum is archived.


Hibernia Gravity Base Structure was built on land, in sections. First the base, then the top. Then they were floated-out and assembled onsite. Not built at sea, while afloat.

The Gravity Base was towed out on May 23, 1997. installed on June 5th, 1997.


It can be done for less then $10k on a “hybrid ferro-epoxy-fiberglass” hull material equal in strength to steel.

OR, for really cheap on a double layer of Big Blocks @ $18/ft. That would be only $3600.00 for a float you can build on.

Free shipping :blush:

(Chad Elwartowski) #57

I have not heard of hybrid ferro-epoxy-fiberglass, is the ferro part a concrete type thing?

I am looking at steel due to the fact that these modules would likely be banging against themselves occasionally. And polyurea sticks best to steel.

Polyurea for the salt water resistance and toughness as far as taking a beating. Plus I have heard from people who have used it on boats that sea barnacles and such do not stick to it.


Well, I couldn’t think of a better description… It’s a construction method I’ve been looking into in order to keep building price low. Quite promising.

Yes, it’s a structural-protective ferrocement “outside layer”.

(noboxes) #59

“ferro” is iron. Usually steel tho. The atomic symbol of iron is Fe. Think “normal rebar” or “expanded metal lath” (usually used in stucco). This is Octavian’s method:

It can be quite sturdy as a building exterior, but won’t take getting bashed into. It beats paint, and nothing can eat it. Big problem years ago, people put it righton wood, and the wood rotted because moisture was condensing on the back side of the stucco. There’s gotchas everywhere!

(Chad Elwartowski) #60

Nice. Better method for ferrocement than I was able to do.

Looks promising.

(Ali) #61

Hi @Elwar

I like your concept, thank you for drawings and detailed info. How about using sacrificial anodes + painted normal (not stainless) steel for your elements. I suppose it should be cheaper than using stainless steel + polyurea?

Sacrificial Anodes on Ships to avoid corosion

(Joshua Rowley) #62

How would you go about connecting the units? A quick and easy way to attach and detach these units would be beneficial to it’s design. My thoughts would be to have winches built within the units, and you can simply reel it in to merge the two. Then once the units are in position, they can lock into place.

(Matias Volco) #63

That’s a very good question that begets to be answered in some detail

(EK) #64

I’m curious about the polyurea use here. I like the idea overall but I’m not sure if I’m following how the polyurea will protect the steel for that long. My biggest concern is that it will just get abraded in spots due to the rubbing and shifting of the different modules. Or just in general that it can/will get scratched and lead to rapid oxidation of the steel underneath. Am I misunderstanding how the polyurea works or do you have another solution for that?

I like the idea and I think steel would be a good material to use if the rusting can be solved, I’m just not sure if this is as foolproof as it might need to be.


While I can’t speak for Chad or his design, a general solution for connecting any seasteading modules would be to just simply raft them up.

My idea was to use steel cables and vertical boat fenders.

Much heavier duty then the above one, but the same idea.

(Chad Elwartowski) #66

I’ve gone back and forth with several thoughts on this. Whether to just use industry standard bumpers or to have them sandwiched together with high powered magnets on the interior (which would allow for splitting apart during an intense wave but snap back together afterwards).

Another thought was SRI’s artificial muscle which produces electricity when pressure is applied and relieved. Though that would take a boatload of experimentation, the implications of the final results would be pretty big (power your module just from bumping into your neighbor).

Maybe Pacific Weave tires? Or just plain tires strapped on.

Yes, definitely a factor. I haven’t experimented enough with polyurea to find the best way to prevent that. There’s the hard stuff in truck beds, then I saw polyurea applied when I was in Afghanistan to the T walls and they were more rubbery. There are many different formulas out there. Again, much experimentation would be necessary.


That crossed my mind too, but the power requirements to generate such strong magnetic fields that could hold in place 1-2-5-etc. tons modules seems to be prohibitive, price wise.

And, for what? So we can just press a button in order to disconnect a module? :blush:



(Chad Elwartowski) #69

I was thinking more in line with the ability for the seastead to break apart in rogue wave situations and snap back together.
But ya, probably makes sense on a small scale but at a large scale not practical.