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mass production of floating family units – concrete shell seasteading

Home Forums Archive Structure Designs mass production of floating family units – concrete shell seasteading

This topic contains 25 replies, has 7 voices, and was last updated by Profile photo of ellmer - http://yook3.com ellmer – http://yook3.com 3 years, 9 months ago.

Viewing 11 posts - 16 through 26 (of 26 total)
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  • #8797
    Profile photo of Eelco

    Those videos certainly look good. It demonstrates the difference between ships and semi-subs what makes it stable is essentially the same principles as what makes semi-subs stable.

    Its good to keep an eye on the scale though; its stable with respect to these shortish waves, but with respect to much longer oceanic waves, I doubt such a structure would be able to accomplish much improvement relative to a simple displacement hull.

    Semi-subs tend to be more expensive than boats of the same carrying capacity; and im not sure id even want to see the pricetag on this thing…

    Profile photo of OCEANOPOLIS

    There has to be a compromise somewhere,…Pick 2, sacrifice 1. You cant have all 3.



    Joep…(submerged part so small…)

    The submerged observatory part can be as big as you want to build it.

    Octavian…(flat cup…customer spec…5cm)

    Hello Octavian the shape can be “almost any shape” including katamaran and trimaran type shapes, in genaral i would go for spheric curves due to the structural strenght such a shell will provide. The main reason why i go for a few standard shapes is the mass production aspect. Any detail building slows the production flow and rises cost. I am not very sure about shells of only 5cm because the concrete cover will be only 2,5cm – a sufficient concrete cover over the rebar is key for the 200year lifespan of industrial marine concrete structures. Many of the problems reported for ferrocement just do not exist for thick walled cast concrete shells. Those shells are ridiculously heavy compared with a carbon fiber yacht – so you will not win a yacht regatta, but they are also ridiculouly economic to build – just right for a floating island or a submarine habitat.


    The chamber structure will be about 2m distance so that a person can crawl in (manhole) for inspection and repair. The chamber walls can be thinner than the outer skin (2,5-5cm) The deck 7cm. The freeboard suggested is similar to a yacht – 1m – but can be as high as the owner wants it. Spheric curved shapes are better because stronger than zylinder shapes. Sharp edges also are not good.

    The floating house on a flat concrete float already exists – what i suggest is a house that is completly or in part inside the shell – to make it much more seaworthy.

    I do not agree that structures must have 400m to provide comfort in waves. Even a 9m structure if properly ballasted like this one –

    can be completly stable and comfortable. You should not look at the ship analogy here – concrete structures behave very differnt in waves especially heavy ballasted ones. Ships suffer a lot because they move rather quick in the high seas due to their commerical shedule. If you just sit there the picture is VERY different.

    The survival of any concrete shell structure in any sea condition is out of question. Even a life raft of 2m diameter can survive – being little more than a tiny structure of fabric and air…what can be in certain risk is big fragile window fronts, it they are not covered by the shell, but surley not the concrete shell itself.
    A concrete shell of 18m like this one


    ….we just finished in raw building – will provide comfortable living conditions (leave coffee cup on table) passing a storm at cape hoorn cruising at 4m snorkel depth.

    Octavian (mobility)

    It is a lot of mobility you would need to avoid any storm – some storms include half of an ocean and “get out of the way” is not so easy. Instead of moving hundreds of miles horizontally you could move a few meter vertically (below the waves) to be completly safe – or just build a reasonable hurricane save shell and ride it out. Hurricane shelters are concrete shells anyhow in most of the cases. So if you already live in such a shell – steel plates for the panorama windows – and you are ready for the dance even in a “relativly vulnerable” open shell structure like the one in the link below.


    Eelco (motion sickness)
    I agree that for seasteading the design criteria are completly differnt than for a ship – motion sickness is top of the list. This is one of the reasons why i have always been so fascinated by “submarine like” habitats. Even very small boats like this one

    give you a motion sickness free living space on open sea. This may not be so obvious on paper – but it is as soon as you do a practical test as we did with the 9m prototype. We where dived just below surface – a storm comming up, trees fallen like matches, 15m yachts calling SOS – ups – what a surprise when opening the hatch – we did not even notice that there was a radical climate change.

    livefreeortry (rebar corrosion)

    There are concrete shells in use as we speak that have been 50 years in marine ambient – never got any maintenance – and the rebar is so clean that you can read the original mill stamp on the bars. Rusting bars are indicators of poor concrete quality in the first place. Today the general opinion is that a well built concrete shell should be expected to have 200 years of maintenance free service life – or more…(http://www.tekna.no/arkiv/NB/Norwegian%20Concrete/Offshore%20Structures.pdf)



    European Submarine Structures AB

    Profile photo of Eelco

    I do not agree that structures must have 400m to provide comfort in waves. Even a 9m structure if properly ballasted like this one can be completly stable and comfortable.

    Sure; because its a submarine. But ordinary displacement hulls need to be rather big to meet the kind of comfort requirements we are aiming for, out in international waters.

    Profile photo of OCEANOPOLIS

    What are the comfort requirements TSI is aiming for?


    Profile photo of OCEANOPOLIS

    200 years is out of my time range. I am 46 man,…..5 cm is ok. Lets not pamper future generations by giving them a “lifetime” + seastead,…Lets them deal with it, in 2060, for a haul out and total refit. That hull is going to be there anyway. Plus, they might want to titanium encapsulate that baby anyway. Regardless,..

    I had a 40′ Samson sloop in ’96 in San Diego, rock solid, build in ’75. Sold in ’99 when I moved to Florida,….talking about regrets! Anyway, I am “sold” on ferro…Too bad you guys are far away, in S.A. We are in Florida with OSDI and we do have an ongoing project, in steel, which I would have preffered to be a ferro. I do like your prices, but the distance would make it prohibitive since the transport. Still, can we envision a future seastead venture somewhere around the Walters Shoal?


    Profile photo of Eelco

    OCEANOPOLIS wrote:

    What are the comfort requirements TSI is aiming for?


    The question doesnt have a one sentence answer, but ill try:

    We aim to accomodate as wide a range of people as possible; not just those with an affinity for the sea. They should be able to engage in all types of activities, including concentrating on desk-bound work.

    There is significant uncertainty in what this implies, especially given that it is noted that people show a strong adaptation to motion sickness effects.

    The ISO standard for horizontal motions is fairly easy to interpret: horizontal RMS accelerations over 0.2m/s2 make performing a job very difficult, and shouldnt occur on a frequent basus.

    The ISO standard for vertical motions is somewhat harder to interpret. Again, we find a 0.2m/s2 limit, but at that point, half the people will be puking their guts out. That is, if they are passengers, with no prior exposure. What would happen to people living on the seastead permanently at that point is unclear. So we are not sure where to go with that, but one thing is clear: a small structure in international waters exceeds that 0.2m/s2 brutally half of the time.

    Half of all people puking their guts out is not a good thing. Regardless, it will happen once or twice a year on a big semisub like clubstead even. We hope to find quantative data on the strength of the adaptation effect, but so far, I have been unable to find any. Until more is known about this, we do feel minimizing motion response is one of our biggest problems.

    One way to deal with it is to operate in calmer waters. We havnt found any international waters more favorable than those that clubstead was subjected to, but at least as a transitionary stage, a more sheltered EEZ location could be considered. That will give you locations with waves only half as bad as those found in international waters; doesnt mean its no longer an issue, but much more managable.


    Eelco wrote:

    …ellmer…Even a 9m structure if properly ballasted like this one can be completly stable and comfortable.

    Sure; because its a submarine. But ordinary displacement hulls need to be rather big to meet the kind of comfort requirements we are aiming for, out in international waters

    i would like to see it as a “deep ballasted floating concrete shell stucture” you can imagine it as a “leg of clubstead without platform” – or a “heavy ballasted ballhouse” – all those are merley artificial distinctions.

    You are completly right that a “ordinary ship shape” needs to be big – and still its movements are close to “worst case” for sea sickness.

    I think most here has been surprised by the video of the movements of the “ballhouse” model – what i suggest is ballast ballhouse to “almost submarine” for heavy conditions in international waters. Maybe even keeping the option to submerge it completly in case of a severe storm.

    The deck could be used as recreational area in good weather – it will be flooded or wavewashed in bad weather – just as it happens in yachting.

    It is a bit “living in the leg of the clubstead” and skiping most of the platform above. If i would ask a person that has never seen such a structure how living “down there” would be, they would problably say dark, humid, bunker like, – my experience is – the contrary is true.

    The inside of the structure (submarine) above is this:

    It is lightfull, temperature regulated, dry bilge – i would have loved to live there during my days as a student – my student room was darker, humider, and i had to share it with a snorting buddy.

    For anybody who lives in the tropic – it is natural to avoid direct sun – you would prefer sunlight that comes filtered trough a meter or two of clear water.

    In my concept the subsurface living space is much more enjoyable than the elevated platform at least in the tropics.

    So we could go for (part or completly) submerged in open international waters – and for the yacht like surface floating family island in protected waters.

    Similar to motor home villages that start to transform to permanent settlements – this would happen on the ocean – the key is to offer a seaworthy family house structure at family house prices.



    Profile photo of OCEANOPOLIS

    My question was related more toward the accomodations since I interpreted your response to Will that beeing a submarine it will have small living areas, no portholes, etc. But I do agree that reducing motion will add to comfort. From personal experience I have notice that people will adapt pretty good, and chewable Dramamine or Meclizine, if chewed but not swallowed will work very good, since will go directly into the blood stream. There is also the widespread misconception that is always “bad” “out there”. In reality, it is pretty tolerable and quite pleasant.



    I would say that what is most sea sickening is rolling movements – most people who will get seasick on a monohull boat will not get seasick on a catamaran type boat of the same size. A ballasted deep loaded round structure like “ballhouse” or the sub above will not roll. Flat and broad structures like the lens island will also avoid rolling movements.

    In general terms what has been done and can be done to avoid seasickness and increase comfort at sea is rounded up in the Comfort at sea – seasteading experiments – thread.

    Speaking for seasteaders that are absolutly not willing to “go submarine” a “platform spread out on the surface” is probably the most economic and easiest solution. If you think about how to increase the wave relevant size of a platform without making it as big as a industrial barge you end up with something like The SEASTAR PLATFORM design – connecting that kind of spread platforms in a convenient way you will end up with the concept GRID SEASTEADING a flexible platform concept spread out over wide extensions with little use of structural building material.



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