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Structure designs open thread

Home Forums Archive Structure Designs Structure designs open thread

This topic contains 57 replies, has 20 voices, and was last updated by Avatar of Capt-Nemo Capt-Nemo 6 years, 2 months ago.

Viewing 15 posts - 31 through 45 (of 58 total)
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  • #1883
    Avatar of Wayne-Gramlich
    Wayne-Gramlich
    Participant

    I’ve got edit rights for the site, so I can get each edit I do into Full HTML mode. I’m not sure that you can get into that mode. Patri knows about the problem, I’m not sure what the Drupal person is doing about it though.

    -Wayne

    #1884
    Avatar of Wayne-Gramlich
    Wayne-Gramlich
    Participant

    Given what an energy ghetto a seastead is in, I suspect we will spring for higher efficiency solar panels. I also expect that they will steer on one axis. The incremental cost will pay back in returned energy.

    Savonious rotor wind generators are great, but they are the least efficient wind generators. We’ll have to see if the extra complexity of a propeller turbine is worth the extra energy it will extract.

    -Wayne

    #1887
    Avatar of Eelco
    Eelco
    Participant

    I agree, nuclear wouldnt be politically feasible. Perhaps at some stage, but not in the near future.

    The problem i see with wind, is that the seastead is least stable with respect to lateral forces. Wind turbines happen to produce a lot of those, and in a fairly fluctuating manner too. I think youd need a really big seastead before you could even place one windmill on it and not have your glasses sliding off your table.

    #1888
    Avatar of Arthur-B.
    Arthur-B.
    Participant

    What about putting wind turbines away from the seastead ? Norsk Hydro is doing floating wind turbines which look like mini seasteads (though they need to be anchored).

    #1890
    Avatar of Wayne-Gramlich
    Wayne-Gramlich
    Participant

    Could you give me a pointer to the Norsk Hydro stuff. When I hit their main page, they show up as an aluminum company. Another page said that they had dropped out of energy and were entirely focused on aluminum these days.

    -Wayne

    #1896
    Avatar of Arthur-B.
    Arthur-B.
    Participant

    Just search floating wind turbine, floating windmill or hywind on google, there are tons of articles about them. They’re tethered to the ocean floor, I don’t see a lot of ways around that :(

    #1918
    Avatar of Jesrad
    Jesrad
    Participant

    I stumbled on www-mpl.ucsd.edu/resources/flip.description.html which gives details about a quasi-seastead built for open ocean research. It uses a long narrow spar design for stability (it is stated it gets better stability than a submarine at 300 ft depth), and reverse osmosis for freshwater, and diesel generators for power. It has 16 inhabitants and has been in use for 46 years so far. No station-keeping nor anchoring when it is in “stead” mode, but interestingly it can moor to underwater pylons. Guess who designed it ? The Scripps Institution.

    #1923
    Avatar of libertariandoc
    libertariandoc
    Participant

    Might be feasible, politically. Toshiba has one of these on the boards http://www.engadget.com/2007/12/19/toshibas-building-a-micro-nuclear-reactor-for-your-garage/

    And they’re trying to put one in Galena, AK.

    #1928
    Avatar of Thorizan
    Thorizan
    Participant

    It is unfortunate that the “Micro Reactor” mentioned is a hoax, as indicated here: http://www.greenlivingtips.com/blogs/185/Toshiba-nuclear-reactor-hoax.html and elsewhere, and the next closest thing Toshiba is creating is for 10 Megawatts of power. That would be more that what is needed in a small seasteading community, but if ours grows ever larger, that is definitely something to consider. Perhaps a seastead dedicated to powering the others around it. Just imagine the extension cords.

    #1929
    Avatar of Jesrad
    Jesrad
    Participant

    I didn’t know about Toshiba’s nuke being a hoax, but in any case they’re not the only ones developing such a power plant. See this for example .

    {Edited by Wayne, to make the link live.}

    #1956
    Avatar of Carl-Pålsson
    Carl-Pålsson
    Participant

    Assuming a spar of ferrocement (reinforced concrete), what practical ways of building it are there? Is it possible to pour entire “tube” sections (full circle), or will these be too large too handle? How about pouring just part of the tube and assembling it from a number of wall sections? How to connect them? On higher levels of the spar the joints will be under compression from the structure above. On lower parts there will be tension from the counterweight. How do we join the sections together so that they can take all these loads? How do we seal the joints to withstand the water pressure? Or is it possible to pour the whole spar at once? Please add your thoughts and ideas on this.

    -Carl

    #1958
    Avatar of thebastidge
    thebastidge
    Participant

    It seems like something along the lines of a simplified oil rig would bring the idea to market quickest. As pointed out earlier, it doesn’t need the precise position of an oil rig, but the stability of that platform would be desirable in many ways. It might even be adaptable to a free-floating plan rather than shallow water.

    It would probably still need to be either a co-op or multi-generational project to pay for itself. But there are commercial co-operatives to use as models.

    #1960
    Avatar of Andrewdblevins
    Andrewdblevins
    Participant

    To Wayne and Vtoldude,

    It seems to me that rotating a long (we are talking 100 – 200 ft correct?) ferrocement spar from horizontal to vertical is just asking for disaster. its my understanding that concrete is very good for compression but any tortion or tensile stresses and it will fall apart or atleast no longer be seaworthy.

    it might be better to float the ballast chamber out into some sheltered waters with out the balast so is floats on its own. Then we build the living quarters so that it floats on its own on top of the ballast chamber, but with a hole slightly larger than the diameter of the spar.

    we pour the spar in the hole with card board molds a few feet at a time, until the spar sticks out above the top of the living quarters, at which time we carefully add a small amount of ballast to sink the ballast chamber and the spar (the living quarters floats on its own). we keep repeating this process untill we have a spar of the correct length and then we secure the living quarters to the spar and pump some of the excess ballest out so that the entire structure raises to the desired height above the water.

    I suppose the problem with this idea is it requires some place with calm very deep water. there also might be problems if too much ballast is added, but i suppose that always was a problem.

    with this method we do not need to transport large pieces of solid cement, so we dont risk cracking it.

    “On higher levels of the spar the joints will be under compression from the structure above. On lower parts there will be tension from the counterweight. How do we join the sections together so that they can take all these loads?” – vtoldude

    Im not sure, but it seems to me that the anywhere above the main boyancy chamber is going to experience compression (assuming most the boyancy comes from the boyancy chamber and not the spar) and that all the tension will be between the boyancy chamber and the ballast chamber. which is good because we do not want tension on the spar. the tension on the ballast chamber may be a little difficult but we should be able to design a structure that can take it.

    your thoughts?

    – Andy

    #1963
    Avatar of libertariandoc
    libertariandoc
    Participant

    How about flexible fabric forms – one smaller than and inside the other, providing the wall thickness? Advantage is that it can be nearly any length, continuous pour, and as it’s made it can be lowered into the water?

    This technology is used for making dome houses – inflate the forms, and shoot the concrete on.

    The water temperature (cool) would help increase the cured strength of the concrete (how much, I don’t know).

    #1964
    Avatar of Revoid
    Revoid
    Participant

    RE libertariandoc yes that is how its done but its not flexible but you have 2 tubes and the concrete tube is made in betwen those two. also you need to put in steel to keep the konstruktion strong enough. btw. cold is not good when concrete is hardning. thats why when working with concrete winter time here in sweden. they got big heaters blowing warm air at the concrete. also they can use portable flamers. tho i doubt sea temp is below 0. anyway back to topic. sure concrete is great. but it is only great for presure forces not pull forces. so basicly the tube connecting the living quarters and water could be made out of concrete.

    but i have a much much better idea.

    make the heavy and strong parts out of steel. anti corrosion steel like the main tube and joints etc. do the living quarters out of aluminium. A. it does not rust. B it is light and C can be verry strong and cheap if built corectly. like aluminum walls and floors can be made like a sandwitch arkitekture. barlast tanks can be made with glassfiber materials. also try to keep tings as modular as possible. so people can use parts and modules they want. not all people will want to grow their own food therefore they wont need alot of “growing space” and use concrete only for the barlast/sink. ok. now to the questions.. Q.aluminium is so expensive. A. true but you dont need to “maintain” it as much it is light and it can be used for almost anything. and unlike concrete aluminium does have a value even if its scrap metal. so yes it costs a little bit more but the worth does not dissepar. its still there. (just asked a co worker about alu pricing. they currently pay 4€/ KG ) so lets say you are going to build a a 20 ton “topplatform” that would cost 800 000€ and now lets say a conrete one would cost 50 000€ and steel 150 000€ (just guessing on those last 2). now for the first. concrete and steel are much more heavy and need a bigger overall struckture to deal with the load. so a 20ton steel platfrom would be much smaler. then a aluminum one. and it would rust. need constant maintnance. and dont forget. iven if the sea stead sinks or gets wreaked or what ever. when we return it to port we still get our 800 000€ back. becuse thats the cost for the raw material. and if it was made out of concrete. you would have to pay someone to take it off your hands.

    so my proposal basicly is.

    Make the seastead platform and living area out of aluminium to keep the weight down.

    make the main “tube/pole/bearing structure out of Steel.

    make the barlast tanks out of alu/glasfiber materials.
    make the sink out of concrete. it can be dumped if need be. and to almost no cost.

Viewing 15 posts - 31 through 45 (of 58 total)

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