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size and shape of the seasteading platform

Home Forums Research Engineering size and shape of the seasteading platform

This topic contains 49 replies, has 8 voices, and was last updated by Profile photo of spark spark 9 months, 3 weeks ago.

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    But how will you feel after being in one of those thru a storm? There’s many days i see on wave maps of the Gulf of Mexico where 10ft/3m waves are everywhere, and this orange thing will be up and down 10ft/3m many times per minute, and rocking side to side as many times. Everything in that blob must be locked down securely at all times, including any humans in it.


    Kat, very valid point ! safe is not “comfy” yet. So you might want to UPGRADE that pod somewhat to make it more comfy.
    Could be a “upgraded house size rescue pod” something like this:

    concrete shell house type rescue pod upgrade
    Or could be a “highly mobile yacht style rescue pod” like this:
    highly mobile rescue pod shell

    But lets face it, all items that do not reach a size 3 times wavelength will not be “comfy at all” in a storm as they track the waves. To get comfy in open sea you need a LOA of at least 100m and a beam of 50m – and that will still not be comfy in tail events type Draupner that can give a full grown ship a good overwash. Smashing the bridge windows at 20m height above the waterline.

    Shell Pods like the ones above will take such a wave submerged, beaten, but still refloating, and alive after the wave went trough.

    Read more about Draupner:

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    The 2 or 3 or 10 times the “wavelength” is a very relative term. In reality, “out there” it means nothing because you gonna get pounded from any direction.

    This is the Saffir-Simpson hurricane wind scale.


    Please note that @ 60 knots, is not even a hurricane, but “just” a tropical storm. Now, watch this 180 m (590 feet) vessel in a 60 knts storm. It lasted 10 days.


    How comfy would that be in a Cat 4 or 5 @ 137 + knts? Please,..lets be realistic. There is no such thing as “comfortable” at sea, the way you imagine it from the prospective of living on land. If you REALLY want to seastead you WILL go through storms like the one above and much worst at least 4-5 times a year if not more. If you can’t, mentally and physically, seasteading is not for you.

    Also, the seastead cannot be “dead in the water” (stationary, without engines) in a storm like that or in any storm. It HAS to make way (move under power), otherwise will capsize. These are realities, I am not making this up. Therefore, everything planned regarding seasteading has to follow and adept to those realities.


    But, the beauty of seasteading is that since there is no ETA or a destination to get to, such storms can be avoided ahead of time.


    Ocean this is a great video that points out the problem – the ship in the video (LPG/C Antwerpen) is clearly tracking the waves, it is a 200 m ship. A Maersk Triple E class ship which is almost exactly twice that lenght will move much much less in the same storm and the same waves. But if you ask a Maersk Tripple E class captain if “life on board is always comfy” he will deny (have been there have done that in my function as member of the cartagena ship repair network), so 400m size is “still not enough” the “magic figure” where you can start to “forget about the problem of your structure tracking the waves and making you “uncomfy” is around 800m and exceeds ship size signifficantly – so we are not talking the size of a “family seastead” anymore when talking about surface floating platforms for the open ocean where inhabitants are comfy all year round no matter what the weather is. – and this “comfy all year round” is exactly the definition of a “home”. Anything that is “smaller and surface floating” is a “concept for a protected bay”. This is why we should diferentiate baysteads from oceansteads. A baystead can start with pod size as it will not have to deal with oceanic waves. This is also one of the reasonings why the “generally accepted way to go” is to start it in a bay – grow it to a signifficant size within the bay and maybe (or not) go oceanic in a second phase when it reaches a suitable size ( 400 – 800 m ). Having a bow feature is also something that will help to deal with oceanic waves. Wave piercing bows are more suitable than classic ship bows as they reduce the sag stress to the seastead in extreme waves. Like in the oil/gas industry going for a ramform would probably be the smartest way to go with a surface floating platform. It features a bow, a extreme wide beam (reduced rolling) a easy way to grow the structure for many years continously a fine water access and marina feature. With a turret mooring (like Ramform Banff) it finds its own way to point the bow in the wave direction with no “engine for manouvering a city” involved.
    For anybody who has a clear idea how a engine for “manouvering a ship” looks like (size of 3 story house need a big crane to change the piston) it is clear why a “engine for manouvering a city in a storm” will not happen.
    Read more about the ramform: http://concretesubmarine.activeboard.com/t51926036/establishing-a-ramform-floating-base-in-the-high-seas-concre/
    Once the structure grows to kilometer diameter size the form becomes less important as any wave on the ocean starts to be a “small wave compared to the structure”.


    To get a good picture how really big man made structures (ships) interact with really big oceanic waves check this video.
    There is a point where “tracking the waves stops” this ship is “almost there”. As the area where this video was shot is Cape Horn i assume this ship is a Post Panamax size as it exceeds the size of the Panama Channel locks (1,000 ft (304.8 m) LOA, 110 ft (33.53 m) beam, 41.2 ft (12.56 m) draft, it is taking the route around the Horn. The waves come aboard as “spray” in a similar way as they would do on a rocky coastal cliff…the freeboard here might be some 16-20m the ship lenghth 300m so those waves are 15m suckers close to the possible maximum according to the linear wave model…unfortunatly the linear wave model is no longer in place after Draupner. If you build your family house on that kind of “platform” even if it is 20m above water level, you will still want it to be a “wave impact safe bunker shell” and “bolted fool proof” to that deck…
    Something like this could take a wave overwash and still be a nice living space.
    concrete shell

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    But even for a (lets say) 1000 m (3000′) LOA seastead (like the one you showed above) you need engines. Even if you don’t navigate, you need them for 3 reasons:
    1. Dynamic positioning (DP), since you will be drifting with whatever current it’s there. Otherwise, you will be starting off California coast and end up in Japan :)
    2. Same idea, but to be able to heave to and ride a storm in order to avoid drifting with a hurricane or a storm.
    3. If the seastead it’s an atoll type with a lagoon open to the stern (my favorite design), you’ll have to keep the bow into the wind so your local traffic, in and out of the lagoon, is protected from the elements, on the lee side.


    Ocean, forget dynamic positioning to check how deep water mooring of big floating platforms is done get the general idea here:
    Also check the concept of turret mooring and why none of the 50 FPSOs mentioned here use engines neither to hold position in up to 2600m depth nor to put the bow into the wind in a storm.

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    Very interesting indeed. I have to admit that I am not following the offshore oil industry news to much. Also my seasteading vision it’s mostly based on the “old school” belief that “Navigare necesse est”, “To sail is necessary”. Therefore I believe that seasteads should be highly mobile, being able to move around, look for new business opportunities whenever they are in order to survive.

    I have nothing against a seasteading venture moored 1000 nm offshore in whatever depth it’s there, engine or not, as long as they can build it and make it happen out there. Best of luck to whoever will do it. But I wouldn’t invest in such venture since it’s not my “gig”. And I am sure that a future mobile seastead will stop by to visit and do business with such a stationary seastead and they will get along quite fine.

    But make no mistakes, if in a hurricane that stationary seastead with no engine, with 500 souls aboard breaks loose from the mooring 1000 nm offshore and God forbid something goes wrong and it puts out a Mayday, nobody will be coming to your rescue in that type of weather, nobody. In this situations is every man for himself and it looks pretty fucked up to me.

    Also make not mistake, if sooooooooooooo lucky that any vessel will respond to that Mayday and put itself and its crew at risk to save the stationary seastead (and that’s a big if…) there will be a HEFTY salvage fee there,…

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    Ocean, you must think outside the box! If such a seastead needs to be evacuated in a hurricane, they all pile into some of Ellmer’s concrete subs and drop overboard and hover at 100ft deep until the storm blows away. Seriously, cast the elevator shaft in the seastead to do just that: detach and drop below the waves as a life-saver submarine. Then they come back to the surface after the storm, when it’s safer, and decide what to do. I hate to rile up Ellmer and have him post more pics and urls to his site, but the concrete sub, or a steel one, has a good place in the ocean. But i do not know why his sub has 12 inch thick walls.
    In a hurricane, no one is going to be out there to save anyone, even if they do a flyby to drop provisions, you can get killed trying to board a boat in 20ft seas.


    Cities and buildings are not supposed to “put out a mayday” only “weekend boaters” are. Cities and buildings are supposed to shelter their inhabitants in ANY climate. In new Orleans everybody who lived in a “weak wood frame house not up to the task” ended to be piled into the Mercedes Benz Superdome which is a shell structure that could resist the climate.
    Kat, I will not talk about “submerged shells” because this is the “size and shape of seasteading platforms” thread – so Alex who started it made it clear that we will talk about surface floating platforms in this space.
    Ocean, i think we need to dump the concept of “rescue of the entrie population” from a seastead completly. When the weather is really severe no helicopter can fly no heroic coast guard man can stand on his feet, no basket can be lowered to transfer anybody to any “other place” it is just not feasible. As the example of New Orleans shows the whole idea of evacuating a city does not work, plans to do so always fail miserably. The only realistic safety base is to build homes that give shelter to their occupants in first place without creating the need to “be rescued by anyone”. Rescue pod size, stadion size, a shell is always the “last resource”. Not coast guard helicopters and cutters. Their crew and equipment is sheltered in a bunker like structure (hangar) like anybody else when the storm is at its climax. The concept of rescue at most can be within the city from one building to another. If one building should collaps, catch fire, etc…

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    Ellmer said: “Kat, I will not talk about “submerged shells” because this is the “size and shape of seasteading platforms” thread – so Alex who started it made it clear that we will talk about surface floating platforms in this space.”
    Sure Ellmer, but i was talking about an emergency escape pod for a surface seastead. I had said :”If such a seastead needs to be evacuated in a hurricane, they all pile into some of Ellmer’s concrete subs and drop overboard and hover at 100ft deep until the storm blows away”. I am sure the water is more calm at 100ft than at the surface during a hurricane, and it’s not like they could escape the hurricane in any lifeboat if they were on the surface. So why not? To me, it’s a perfect reason to have such a vessel on a surface seastead.

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    So, I guess since we won’t send a Mayday, we shouldn’t have VHF radios on board. Since we’ll “dump the concept of rescue of the entire population from a seastead completely” we won’t need live vests for the entire crew and passengers or life boats or abandon ship kits with water, tablet food, sun screen lotion and medical first aid supplies.

    All this because it’s 100 % GUARANTEED by the builder that shell seastead will be 100 % safe with no engine and none of the above, hanging by a steel cable in 2600 m of water 1000 nm offshore.

    As I said, best of luck with it. There is a very good reason that engineers build floating structures and sailors run them.


    As city evacuation in practice shows “the save spot to evacuate to” is a shell dome, so the general idea is to go to something like a shell dome in first place . I would not give a dime for the concept of “survival based on live vests and boats” in a category 4 hurricane… i would take my family to a dome structure and wait in there until the hurricane is over. Just as the people of New Orleans did. Giving a “life vest and a radio” to the occupant of a seastead is a bit like giving a parachute to the office lady in a highrise building in Manhattan so that she can “jump out of the window” when the tower goes to hell as the next hurricane hits town… Design the tower hurricane proof is much more feasible and this is how it is done. It is just a “necessary design feature” and New York actually IS hurricane zone, and the towers ARE designed hurricane proof – all of them.
    mercedes benz dome
    Mercedes Benz Dome New Orleans – the big survival shelter…it IS designed hurricane proof and it showed that it IS up to that task.
    One of the things that set a seastead apart from a ship is, that it is not “sailed by sailors” and not “built by shipyards” and it can not longer be handled like a ship and less like a “weekend boat” and this includes “rescue plans for the crew “. A seastead is supposed to have a “population” not a small “crew of sailors”, and the population is supposed to include babies, hospital patients, and old people that can not grab a lifevest and jump overboard in a category 4 hurricane to be rescued by a “coast guard”. If a seastead is not “inherently safer at sea than any ship” it is no “stead” at all and the engineering task is failed completly.

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    The total of building costs and upgrades/renovations to the Mercedes Benz SuperDome in New Orleans is 3/4 of a Trillion USD in 2013 value. And it doesn’t float, and has no life support systems, and no apartments for those living aboard it. It is not meant to be moved around in waves, it is anchored solidly to the ground, which is the building’s “support structure”.
    What would the cost be to build your https://dl.dropboxusercontent.com/u/183289187/seasteading/floating-honeycomb-shell-dome-stadion-seastead.jpg? Who is going to pay to build it? Where will the money come from to keep it running? If a 300ft long barge costs $80,000 per year to run, surely that pie-in-sky never-be-built dream will cost $millions per year just to make water and power for those living on it, deal with their food and waste, and keep the thing from sinking.
    It bothers me a lot that those outrageous dream images are “what the future of seasteading is”, because none of us will see that happen. Get real. Solve the problems we already have.

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    I do understand what you are saying. But the “level” of seasteading you are talking about now is in the the range of 3000’+ LOA structure, displacing millions of tons, with a starting price tag of at least $10-20 Billion. And I did say that I don’t have a problem with it and if someone has the money and will to do it, kudos to them. But how realistic is that such project will happen in our lifetime? You tell me…

    And what happen to the incremental & modular seasteading ideology that at some point we all seem to agree upon?

    What is wrong with a 80′ or a 120′ or a 200′ seastead, population from 10 to 50 that we can REALLY build in the next few years? And keep on building them, attach them to each other, and grow little by little, and by doing so we’ll be GETTING SOMEWHERE instead of still just keep on talking about it and getting nowhere…

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