I personally entertain the notion of creating a "neo-nesian" floating micro-nation by lashing "surplus" ships between manufactured "land" produced by plasticizing (from recycling industries based on refuse management for mainland customers) seaweed foam (expanded with sequestered CO2, another intake fee based industry) into modular building blocks and covering them with composted (again refuse management) soils. Granted my design would actually be a floating island and would rely on mass for protection, but I prefer the illusion of landmass. I also wonder about the viability of using "Seament", if you could generate the power with wind, solar, and wave power and use steel forms derived from recycling industries, it could substitute for your cement at a reduced cost and increased autonomy.
This is a simple concept, very quickly opped into my head, so I decided to share it.
It is for dealing with the natural movement of smaller and even larger seasteads when it comes to waves.
The first thing I wish you to imagine is a bowl of milk, then place a smaller bowl in the bowl of milk. After you have done this, tape the smaller bowles edges to the edges of the larger bowl. Make sure that they are both loosly connected. Now that this is done, place the contraption in a bath tub. Make small and or large waves with your hands and observe the movements of the small bowl. You will notice that the larger bowl swings with the waves, but the smaller one stays for the most part, straight up. Now Imagine this on a larger scale, where a seastead is floating in it's freshwater supply, brought by a filter below (Shaped like a large version of the water purificaiton systems today). This would keep the seastead from moving severly during even rough weather. Although it might not be applicable for very large models, and extremely rough weather would make it useless, this would be good for medium to small seasteads to prevent some degree of seasickness.
Also, you could devise a method of bringing in extra power through waves, especially in larger seasteads. The constant motion of the above model could probably power a few lights or the water purification system itself if it could store power.
I am currently director of engineering here a the SeaSteading Institute and I need to get our base design up on the web site. The base design is something called a spar buoy. A spar is a long beam that sits vertically in the water. We ballast one end of it down with scrap steel and build an interesting living space on top. The goal of this design is to have a seastead that is inexpensive enough for an individual to own.
There are other designs based on breakwaters that seem to be much more involved. Your nested bowl design is basically a breakwater. I am not enthusiastic about breakwater designs because they will necessarily be large and require a "government" to manage them. Personally, I'm trying to for less government, not more. However, I can see no technical reason for them not to work. I'm less convinced of their economics though.
Wayne, can your design be assembled on the ocean? In other words, can we put the spar, the platform, and the living space on some kind of ship, sail out to the designated location, and then connect the pieces and deploy them on the water?
If possible, I think that would be a big win.
I'm very skeptical of the Tug-the-Spar concept, especially if the designated location is far from the construction location. If it takes a month to deploy one spar, and the SI has a limited number of Tugs, it's going to take a huge amount of time to deploy a significant number of seasteads.
(I'm having problems with the RSS feeds not catching everybody's
replies, so I have manually sweep trough the feeds to catch comments.
Hence, the delay in responding...)
The base design (which I am madly trying to enter into the
web site) is designed for construction at a port with limited
draft. The spar is assembled horizontally and rolled off the
dock into the water. The living quarters reside on top of
something called the safety hull. This can be craned from
land onto the water (no dry dock.) The living quarters and
spar are towed out into deep ocean. There is a tedious process
of redistributing the ballast in the spar to take it from a horizontal
to vertical. In calm seas, the living quarters are floated on top
of the spar. Finally, the spar is raised in height by pumping air
into some air ballast tanks. Lastly, the spar has its own mobility
motors that allow it to take its time to move out to the desired
location.
In short, the tug boats only need to tow a short distance from
the deployment port to a deep sea location several miles off shore.
Long distance deployment is done by seastead propulsion system.
I doubt that a seastead will move very fast, so it will take a while
to move a thousand kilometers.
Longer term, it will be desirable to import the raw materials to
the seastead community and assemble them on site. This is possible,
but I am sure we will be several design iterations before anybody
seriously proposes that.
I hope that answers your basic question and I'm sure it will
garner additional questions.
I fear it might be quite expensive to have the equipment that could move something with the profile of a seastead even against normal sea currents. I can see it being desirable for making manouvers, but that can be done with tugboats as well.
I think renting tugboats for long hauls, and renting/buying a seperate one for manouvers might be much more efficient. Having one tugboat lying around doing nothing most of the time is still much less wastefull than having 10 propulsion systems lying around doing nothing. One such a custom made propulsion system is probably already much more expensive than one second hand tugboat.
I'm sure we can do some self propulsion, but I am not confident about moving long distances at all. It is very hard to compete with good old oil dug out the ground and brewed into diesel fuel. If you want to move faster, fossil fuels may be the way to go.
Wayne - it sounds great. Very clever to have the living quarters floated over the spar, and then lifted into the air by air pumps.
I second Eelco's concern about mobility of the spar. I'm also thinking that even if the equipment is affordable, movement might be very energy intensive.
I feel like it would be more efficient to load multiple seasteads onto a cargo ship, drive the cargo ship out to the destination, and then deploy everything. Then the cargo ship could also be on standby in case of emergency (e.g. during a storm, everyone could get on board the ship). This "mother ship" model would have downsides, of course, such as the fact that everyone would have to ship out at the same time.
I second Eelco's concern about mobility of the spar. I'm also thinking that even if the equipment is affordable, movement might be very energy intensive.
I am sure that moving a spar is going to be energy intensive. There is no free lunch. Either you move slowly with the limited solar/wind/wave energy available at the spar or you buy some fossil fuel and burn it to move more quickly.
The seastead is going to need some amount of station keeping capability to keep it at rest relative to its neighbors. It seems extremely likely that the station keeping task can be powered off of solar/wind/wave power. In addition, the propulsion system that is used for station keeping can also be used for spar relocation to another site. Since I expect relocation to be infrequent, I do not expect people to invest heavily high speed seastead self propulsion. They will either rent a tug or accept slow speed self propulsion. The decision will be an economic one.
I thought some sort of rigid connection between neighboring steads' was the preferred method of relative positioning? Anyway, since seacurents arnt not very variable, one buoy should give a rather stationary orientation to your seastead.
What about the powering you mentioned? I can see how solar would work, although its intermittent. But wind? That is going to have to involve rolling out of your bed, wether its a windmill or a sail. And what about waves? You mean some way of using the force of the waves directly, or through a generator? It might work great, but i personally feel we should stick with proven technology as much as possible for v1.0. You can always add features later, but if your prototype is a failure, that might just shatter the movement.
The baseline for power is solar panels with battery storage. This is tried and true but not necessarily cheap.
The next level for experimentation is wind power. It is supposed to be the case that wind turbine coupled to a propeller captures enough energy to drive into the wind. It remains to be seen whether a wind turbine, connected to generator, connected to electric propellers are capable of overcoming the movement due to wind.
Various forms of the spar design can be assembled in the ocean. It is not an easy environment to construct in, so we are focusing on mostly land based construction at the moment. Sea based construction will probably require specialized construction facilities, which will be more expensive than their land based counter parts.
If seasteads can be built out of small enough modules (the Lego brick approach ?) those parts could be easily manufactured in series on the platform. Or if they're too big for sea construction, by making sure they can by towed on site they could be chain-manufactured on land and sent in convoys behind a tug boat.
In the long run I´d say nuclear power is the way to go for a full scale seastead. One idea is to offer designers of experimental plants such as the pebble bed reactor a place to set up a test facility. They´d get rid of government red tape and a lot (but probably not all) of the anti-nuclear protests, and the seasteders get cheap power and other goodies, perhaps hydrogen to run boats and aircraft on.
Let me reiterate that the above scenario is a possiblity in the long run, not today.
In the short term I would bet good old petroleum will be the cheapest way to produce power. Considering that the seasted will need propulsion for pretty much its entire lifespan I think an integral propulsion system will be better/cheaper/more practical than tugboats. Adding a propeller on a shaft through the spar and a rudder doesnt seem that complicated to me.
Anyway, when the first commercially self-sustaining seasteds are a reality, the power production issue will work itself out automatically. Energy producers will buy property on the seasted and install generators of whatever type and sell power to other inhabitants and businesses.
This is my first post, so hi everyone!
Sorry about the bunched together text. I can´t get the line breaks to work.
That also occured to me: a seastead might be a great way for nuclear scientists to do research. No way of selling to landlubbers though, barring the construction of 200 nautical mile power lines. It would be neat if it were in combination with power intensitive industry, like aluminium or something. We could copy the business model of iceland: cheap power in combination with a transportation hub.
Also, nuclear reactors are possible at the scale of submarines, so they are scalable enough. But thats on a military budget, which we do not have.
Considering that the seasted will need propulsion for pretty much its entire lifespan
I think the only two options for day to day operation are going with the flow or anchoring. Keeping engines of that size running on a permanent basis doesnt sound too attractive to me, financially.
Adding a propeller on a shaft through the spar and a rudder doesnt seem that complicated to me.
Then build us one id say. But if you would ask a professional naval drivetrain manufacturer, id say this situation is sufficiently far enough out of their box so that you wont get it even near the price of a series-produced tugboat with a similar engine. And one tugboats servicing a bunch of seasteads will ofcource get a proportionally higher utilization rate.
In general, I am a big fan of nuclear energy. The US Navy is largely nuclear and, hence, demonstrates that feasibility of nuclear at sea. However, access to nuclear technology is pretty constrained world wide. While it is possible to obtain uranium from ocean water, it has not been done on a commercial scale yet. If you can not get nuclear fuel, it is hard to go nuclear.
Though going nuclear would be a nice and probably very efficient option, the advantage that you might get it from ocean water (provided we could afford the machines to get it and know how to do it) is very small. Any Seastead will never be autonomous, having to import lots of things (paper, eggs, clothing, concrete, whatever), so as it will have to import things anyway, importing the tiny amounts of uranium a Seastead would need shouldn't be the problem.
The biggest problem would, however, be the usage of uranium itself. The loss in public support would be huge, neighbouring states will start accusing us of "helping terrorists " or at least "endangering civilians", the country whose flag we fly will start complaining, and the end of Seastead would be within weeks. (Using depleted uranium as balast would be in the same category).
There is no technical reason why nuclear power wouldn't work, but the political ramifications would be difficult. I doubt we will see any nuclear power generation on seasteads in the next 20 years, unless there is a serious technology break through (e.g. polywell fusion.) Given the long time frame for nuclear, I will tend to focus my energies on the more surefire solar/wind/wave technology. Even there, wind and wave power are not really surefire.
Eelco, I guess everything depends on what stage in the evolution of seasteading we´re talking about. I admit that most of what I proposed won´t be feasible on the experimental/prototype/baystead stage. The situation changes quite a bit if we imagine a time in the future when seasteading has become more or less "mainstream", with mass production of spar buoys complete with power, propulsion and all the basic facilites most ´steads will need. At that point adding propulsion units might be more economical over the life of the platform, adding all the costs, running and fixed together. Having the possibility to move easily and instantly without relying on external services seems in line with the idea of the dynamic geography, as far as I can tell, anyway. I can´t offer you any finished blueprints of a seasted propulsor unit, :-) but here´s a couple of links anyway: http://en.wikipedia.org/wiki/Azipodhttp://en.wikipedia.org/wiki/Voith-Schneider I´m not sure those would be ideal for our structure, though. Perhaps one feasible way would be to use two electric motors rather like the Azipod (one on each side of the spar), but they wouldn´t need to be able to swivel. That could both rotate the seastead in place and drive it forwards and backwards. The Voith-Schneider device gives you the ability to move in any arbitrary direction regardless of your present orientation however, but it might need to sit below the counterweight which might give problems with tilting due to the offset between the center of gravity and the propulsive force.
Personally I feel that it would be nice if a Seastead could move around or at least stay in one place without using a tugboat. Mooring is extremely expensive so it's probably not an option (unless in shallow waters of course). Mooring in the SF Bay makes a ship a "floating home", may be if it keeps sailing we don't have to pay rent? (see http://www.floatinghomes.org/dnload/fhrl.pdf for information on this).
If Seastead is outside territorial waters, it should not unintentionally drift towards land.
Btw, line breaks are inserted automatically? Just type real enters in the text.
Joep
I dont expect to make use of dynamic geography very often, actually. The possibility of it should do most of the work to begin with.
I know mooring can get extremely expensive, but i think we can keep it managable, because there is just so much choice for locations. We can look for shelfs, so line lengths will stay managable. And we dont need exact positioning, like an oilrig for instance, so just one line would be fine, perhaps shared between a bunch of seasteads.
In its simplest form, all we need is a block of concrete/steel/whatever, lined to a buoy. We kick that off the tugboat in the desired location, no mechanism for reeling in or anything, and you can hook up a bunch of steads. That should be constructable at a cost << seastead. Youll need a new one every time you move, but i think it would be a minor cost compared to the whole moving operation even.
But anyway, were are not yet at a point to start ruling things out, we need to consider all options in more detail.
Another reason for needing precise maneuvering gear is if you need to move the seasted from within the middle of a grouping of other platforms. I seem to recall that this would be managed by lowering the moving platform so that it clears the superstructures of the neighbors and then navigating out "below" them, so to speak. Using tug boats pulling on ropes for such a critical maneuver appears difficult at best to me.
Thinking some more about possible placement of the propulsors I think they probably could sit below the counterweight /flotation cylinder. After all, the center of gravity would be situated somewhere in this region, if I understand things correctly. I guess in the end only testing will settle this. Anyone know if there has been any actual tests with models (poolstead etc), and where results from this can be found?
That PDF is a perfect example of why seasteads are needed in the first place :-).
I might have used the plain text editor last time, lets see if this will look better...
Regarding fossil fuels, I still think that Biodiesel brewed from algae http://www.unh.edu/p2/biodiesel/article_alge.html has alot of potential for a seastead, perhaps a solar still/furnace could provide the energy ("free" energy) required for processing.
But on the subject of "free" energy;
I recall seeing an interesting propulsion system many years ago, an inventor from a Norse nation (I cannot recall which one) had retrofitted a row boat with three outboard "dolphin" flippers on outriggers, one at the stern and one each at the sides just ahead of the midpoint. As the bout bobbed on the waves the (neutral bouyancy) flippers pivoted up and down creating forward thrust. Granted it was slow, but it was forward thrust.
I imagine that such flippers could be mounted, at the vertical fulcrum point (of the spar, so as not to "rock the boat"), on outriggers/downriggers attached to the floating dock (as mentioned in the book). Use a good ole rudder to steer and there you have it slow but free long distance propulsion. As long as you have any wave action you have a proportional forward thrust. I would still use manuvering thrusters for precision navigation (docking and the such), but given their limited use I think you could get away with smaller/weaker solar/wind charged electric motors for tight manuvering.
P.S. My line breaks, and html tags, won´t play ball either.
It is extremely important that seastead be able to maintain a relative position with its neighbors. In addition, because there will likely be some solar panels on top of the seastead for daytime power collection, it is probably a requirement that the seastead not rotate while it is maintaining position. The reason for this is because the solar panels will probably have limited sun tracking capability.
While is is possible to do station keeping with three propellers spaced 120 degrees apart, we will probably opt for 4 propeller spaced 90 degrees apart. No swivel capability or rudder is required, the propellers can be fixed to the side of the seastead. This allows us to separately move the seastead in X and Y (i.e. East-West and North-South). In addition, the 4 propeller system is capable of twisting the seastead as well.
By the way, if you can find the [Input Format] and set it to [Full HTML], then this wacky forum system will insert paragraph tags around each line. The lines have to be entered without any carriage returns though. Anyhow, that I how I can get paragraphs to show up.
Regarding station keeping for the purpose of keeping the sloar panels aligned, it won't be necessary if you use the amorphous thin film panels. The thin films currently have about half of the peak conversion efficiency as the crystaline panels, but since they can convert at any angle to the sun (and partially shaded, and partially damaged, and regardless of temperature) they have a much greater overall efficiency rate. The bottom line with the thin film solar panel is, if light touches it, it make electricity.
Also great strides are being made in vertical axis windmill generators, they seem to have a greater ability to self regulate in high winds, making them less damage prone.
And I still can't seem to get paragraph breaks, what am I missing?
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.
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.
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.
Station keeping/transport: Wayne, 3 or 4 propellers does sound like a simple way of getting full movement in all directions plus rotation. You should be able to do everything with three though, including rotation. I assume you mean to put them on a 90 degree angle out from the structure? You´d lose efficiency when translating with three though, but that´s the only drawback I can see. Nuclear: How about just buying the fuel? Do you forsee political problems? Eelco, yes, the possibility to move will go a long way. But that option needs to be real, and not involve high risk and cost, such as using a tug boat to move a platform from in the middle of a complex of a hundred others without ruining everybody elses day. If there is a non-negligible risk of crashing into another platform, very few will risk doing it, and then dynamic geography will fail. But, like you say reality will settle this matter eventually regardless of our argument. And, will someone for the love of all that is holy explain to me like I am a four year old how you create line breaks. I have read all your suggestions but I cant find the buttons to push or understand what you mean. Thank you.
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).
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.
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 :(
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.
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/
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.
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.
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.
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).
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.
Currently, there's probably no application of a large-enough scale, but some form of advanced ceramic may well be better for shell structures than conrecte, if more expensive.
RE: aluminim vs steel. Aluminim does corrode, it simply corrodes a nice thin film of aluminim oxide which then effectively blocks oxygen from getting further in, while steel corrodes and flakes, which makes more steel available to the air for further corrosion. However, any physical stress which is applied to the aluminum can cause the protective coating of aluminim oxide to be compromised, and aluminim is not very strong. Again, fiber glass or ceramic might be better.
Good point on the recycling of materials, but you miss a point about disposing of concrete- you wouldn't tow that back to port, you would just drop it in the ocean. Even if you had to cut away some recyclable superstructure to do so, it would cost less in fuel than you would lose in recoverable materials, and there would be no disposal fees.
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.
Andrew, sorry I totally missed your post and did not catch it until now...
I lose sleep at night at the thought of taking an 70 meter spar in the horizontal configuration and taking it vertical in the middle of the sea. It may turn out to be a show stopper. We need to get somebody who can do the structural analysis on board to tell us what is/is not feasible.
How has it been done in the past? It seems like the launch would almost necessarily mean taking a bare shell out to an adequate depth, flooding most of it (in stages) aand then building out the physical plant and interior after pumping it dry. It would really be a limiting factor to function if the design must include a flooding process that involves most of the length of the spar on at least one side to gradually and evenlyshift ballast to the bottom.
Even a scale model has me scratching my head a bit. I did somre quick googling on my closest area for a 1/4 scale model under easy conditions. I was thinking Lake Billy Chinook, and using a spar buoy house as a summer rental for promotoional and cost-recuperative purposes.
I personally entertain the
I personally entertain the notion of creating a "neo-nesian" floating micro-nation by lashing "surplus" ships between manufactured "land" produced by plasticizing (from recycling industries based on refuse management for mainland customers) seaweed foam (expanded with sequestered CO2, another intake fee based industry) into modular building blocks and covering them with composted (again refuse management) soils. Granted my design would actually be a floating island and would rely on mass for protection, but I prefer the illusion of landmass. I also wonder about the viability of using "Seament", if you could generate the power with wind, solar, and wave power and use steel forms derived from recycling industries, it could substitute for your cement at a reduced cost and increased autonomy.
Brilliant
A great idea!!!!
Especially useful for trading with other seasteads and with the mainland.
Reply, my proposal for dealing with waves.
This is a simple concept, very quickly opped into my head, so I decided to share it.
It is for dealing with the natural movement of smaller and even larger seasteads when it comes to waves.
The first thing I wish you to imagine is a bowl of milk, then place a smaller bowl in the bowl of milk. After you have done this, tape the smaller bowles edges to the edges of the larger bowl. Make sure that they are both loosly connected. Now that this is done, place the contraption in a bath tub. Make small and or large waves with your hands and observe the movements of the small bowl. You will notice that the larger bowl swings with the waves, but the smaller one stays for the most part, straight up. Now Imagine this on a larger scale, where a seastead is floating in it's freshwater supply, brought by a filter below (Shaped like a large version of the water purificaiton systems today). This would keep the seastead from moving severly during even rough weather. Although it might not be applicable for very large models, and extremely rough weather would make it useless, this would be good for medium to small seasteads to prevent some degree of seasickness.
Also, you could devise a method of bringing in extra power through waves, especially in larger seasteads. The constant motion of the above model could probably power a few lights or the water purification system itself if it could store power.
Closed breakwater ?
That's half-way between the bubbles proposal, and the breakwater design. Interesting.
Vessel Stability IN Elevated Sea-States
The HARTH technology may be appropiate to your interests for both mobility, large platforms and ultra-stabiity in elevated sea-states.
Base Design
I am currently director of engineering here a the SeaSteading Institute and I need to get our base design up on the web site. The base design is something called a spar buoy. A spar is a long beam that sits vertically in the water. We ballast one end of it down with scrap steel and build an interesting living space on top. The goal of this design is to have a seastead that is inexpensive enough for an individual to own.
There are other designs based on breakwaters that seem to be much more involved. Your nested bowl design is basically a breakwater. I am not enthusiastic about breakwater designs because they will necessarily be large and require a "government" to manage them. Personally, I'm trying to for less government, not more. However, I can see no technical reason for them not to work. I'm less convinced of their economics though.
-Wayne
re: Base Design
Wayne, can your design be assembled on the ocean? In other words, can we put the spar, the platform, and the living space on some kind of ship, sail out to the designated location, and then connect the pieces and deploy them on the water?
If possible, I think that would be a big win.
I'm very skeptical of the Tug-the-Spar concept, especially if the designated location is far from the construction location. If it takes a month to deploy one spar, and the SI has a limited number of Tugs, it's going to take a huge amount of time to deploy a significant number of seasteads.
Dan
Tugboats for this kind of
Tugboats for this kind of work are usually rented, not owned.
Assembly
DanB:
(I'm having problems with the RSS feeds not catching everybody's
replies, so I have manually sweep trough the feeds to catch comments.
Hence, the delay in responding...)
The base design (which I am madly trying to enter into the
web site) is designed for construction at a port with limited
draft. The spar is assembled horizontally and rolled off the
dock into the water. The living quarters reside on top of
something called the safety hull. This can be craned from
land onto the water (no dry dock.) The living quarters and
spar are towed out into deep ocean. There is a tedious process
of redistributing the ballast in the spar to take it from a horizontal
to vertical. In calm seas, the living quarters are floated on top
of the spar. Finally, the spar is raised in height by pumping air
into some air ballast tanks. Lastly, the spar has its own mobility
motors that allow it to take its time to move out to the desired
location.
In short, the tug boats only need to tow a short distance from
the deployment port to a deep sea location several miles off shore.
Long distance deployment is done by seastead propulsion system.
I doubt that a seastead will move very fast, so it will take a while
to move a thousand kilometers.
Longer term, it will be desirable to import the raw materials to
the seastead community and assemble them on site. This is possible,
but I am sure we will be several design iterations before anybody
seriously proposes that.
I hope that answers your basic question and I'm sure it will
garner additional questions.
-Wayne
Wayne:
How sure are you about the self-propulsion?
I fear it might be quite expensive to have the equipment that could move something with the profile of a seastead even against normal sea currents. I can see it being desirable for making manouvers, but that can be done with tugboats as well.
I think renting tugboats for long hauls, and renting/buying a seperate one for manouvers might be much more efficient. Having one tugboat lying around doing nothing most of the time is still much less wastefull than having 10 propulsion systems lying around doing nothing. One such a custom made propulsion system is probably already much more expensive than one second hand tugboat.
Self-Propulsion
I'm sure we can do some self propulsion, but I am not confident about moving long distances at all. It is very hard to compete with good old oil dug out the ground and brewed into diesel fuel. If you want to move faster, fossil fuels may be the way to go.
-Wayne
basic design
Wayne - it sounds great. Very clever to have the living quarters floated over the spar, and then lifted into the air by air pumps.
I second Eelco's concern about mobility of the spar. I'm also thinking that even if the equipment is affordable, movement might be very energy intensive.
I feel like it would be more efficient to load multiple seasteads onto a cargo ship, drive the cargo ship out to the destination, and then deploy everything. Then the cargo ship could also be on standby in case of emergency (e.g. during a storm, everyone could get on board the ship). This "mother ship" model would have downsides, of course, such as the fact that everyone would have to ship out at the same time.
Spar Mobility
With regards to the comment below:
I am sure that moving a spar is going to be energy intensive. There is no free lunch. Either you move slowly with the limited solar/wind/wave energy available at the spar or you buy some fossil fuel and burn it to move more quickly.
Im not sure i understand: i
Im not sure i understand: i didnt have anything but oil in mind.
On thing at a time id say: this is going to be difficult enough without trying to be a revolutionary in every single aspect.
Spar Mobility
The seastead is going to need some amount of station keeping capability to keep it at rest relative to its neighbors. It seems extremely likely that the station keeping task can be powered off of solar/wind/wave power. In addition, the propulsion system that is used for station keeping can also be used for spar relocation to another site. Since I expect relocation to be infrequent, I do not expect people to invest heavily high speed seastead self propulsion. They will either rent a tug or accept slow speed self propulsion. The decision will be an economic one.
-Wayne
I thought some sort of rigid
I thought some sort of rigid connection between neighboring steads' was the preferred method of relative positioning? Anyway, since seacurents arnt not very variable, one buoy should give a rather stationary orientation to your seastead.
What about the powering you mentioned? I can see how solar would work, although its intermittent. But wind? That is going to have to involve rolling out of your bed, wether its a windmill or a sail. And what about waves? You mean some way of using the force of the waves directly, or through a generator? It might work great, but i personally feel we should stick with proven technology as much as possible for v1.0. You can always add features later, but if your prototype is a failure, that might just shatter the movement.
Local Power
The baseline for power is solar panels with battery storage. This is tried and true but not necessarily cheap.
The next level for experimentation is wind power. It is supposed to be the case that wind turbine coupled to a propeller captures enough energy to drive into the wind. It remains to be seen whether a wind turbine, connected to generator, connected to electric propellers are capable of overcoming the movement due to wind.
Wave power is very speculative.
-Wayne
Ocean Construction
Sorry, I did not catch your question until now.
Various forms of the spar design can be assembled in the ocean. It is not an easy environment to construct in, so we are focusing on mostly land based construction at the moment. Sea based construction will probably require specialized construction facilities, which will be more expensive than their land based counter parts.
Modular constructoin ?
If seasteads can be built out of small enough modules (the Lego brick approach ?) those parts could be easily manufactured in series on the platform. Or if they're too big for sea construction, by making sure they can by towed on site they could be chain-manufactured on land and sent in convoys behind a tug boat.
In the long run I´d say
In the long run I´d say nuclear power is the way to go for a full scale seastead. One idea is to offer designers of experimental plants such as the pebble bed reactor a place to set up a test facility. They´d get rid of government red tape and a lot (but probably not all) of the anti-nuclear protests, and the seasteders get cheap power and other goodies, perhaps hydrogen to run boats and aircraft on.
Let me reiterate that the above scenario is a possiblity in the long run, not today.
In the short term I would bet good old petroleum will be the cheapest way to produce power. Considering that the seasted will need propulsion for pretty much its entire lifespan I think an integral propulsion system will be better/cheaper/more practical than tugboats. Adding a propeller on a shaft through the spar and a rudder doesnt seem that complicated to me.
Anyway, when the first commercially self-sustaining seasteds are a reality, the power production issue will work itself out automatically. Energy producers will buy property on the seasted and install generators of whatever type and sell power to other inhabitants and businesses.
This is my first post, so hi everyone!
Sorry about the bunched together text. I can´t get the line breaks to work.
Hi Carl
That also occured to me: a seastead might be a great way for nuclear scientists to do research. No way of selling to landlubbers though, barring the construction of 200 nautical mile power lines. It would be neat if it were in combination with power intensitive industry, like aluminium or something. We could copy the business model of iceland: cheap power in combination with a transportation hub.
Also, nuclear reactors are possible at the scale of submarines, so they are scalable enough. But thats on a military budget, which we do not have.
Considering that the seasted will need propulsion for pretty much its entire lifespan
I think the only two options for day to day operation are going with the flow or anchoring. Keeping engines of that size running on a permanent basis doesnt sound too attractive to me, financially.
Adding a propeller on a shaft through the spar and a rudder doesnt seem that complicated to me.
Then build us one id say. But if you would ask a professional naval drivetrain manufacturer, id say this situation is sufficiently far enough out of their box so that you wont get it even near the price of a series-produced tugboat with a similar engine. And one tugboats servicing a bunch of seasteads will ofcource get a proportionally higher utilization rate.
Nuclear Seastead
In general, I am a big fan of nuclear energy. The US Navy is largely nuclear and, hence, demonstrates that feasibility of nuclear at sea. However, access to nuclear technology is pretty constrained world wide. While it is possible to obtain uranium from ocean water, it has not been done on a commercial scale yet. If you can not get nuclear fuel, it is hard to go nuclear.
-Wayne
Nuclear is (or should be) cool but
Hi Wayne,
Though going nuclear would be a nice and probably very efficient option, the advantage that you might get it from ocean water (provided we could afford the machines to get it and know how to do it) is very small. Any Seastead will never be autonomous, having to import lots of things (paper, eggs, clothing, concrete, whatever), so as it will have to import things anyway, importing the tiny amounts of uranium a Seastead would need shouldn't be the problem.
The biggest problem would, however, be the usage of uranium itself. The loss in public support would be huge, neighbouring states will start accusing us of "helping terrorists " or at least "endangering civilians", the country whose flag we fly will start complaining, and the end of Seastead would be within weeks. (Using depleted uranium as balast would be in the same category).
Joep
Nuclear Technically Feasible, Politically Not
There is no technical reason why nuclear power wouldn't work, but the political ramifications would be difficult. I doubt we will see any nuclear power generation on seasteads in the next 20 years, unless there is a serious technology break through (e.g. polywell fusion.) Given the long time frame for nuclear, I will tend to focus my energies on the more surefire solar/wind/wave technology. Even there, wind and wave power are not really surefire.
-Wayne
Eelco, I guess everything
Eelco, I guess everything depends on what stage in the evolution of seasteading we´re talking about. I admit that most of what I proposed won´t be feasible on the experimental/prototype/baystead stage. The situation changes quite a bit if we imagine a time in the future when seasteading has become more or less "mainstream", with mass production of spar buoys complete with power, propulsion and all the basic facilites most ´steads will need. At that point adding propulsion units might be more economical over the life of the platform, adding all the costs, running and fixed together. Having the possibility to move easily and instantly without relying on external services seems in line with the idea of the dynamic geography, as far as I can tell, anyway. I can´t offer you any finished blueprints of a seasted propulsor unit, :-) but here´s a couple of links anyway: http://en.wikipedia.org/wiki/Azipod http://en.wikipedia.org/wiki/Voith-Schneider I´m not sure those would be ideal for our structure, though. Perhaps one feasible way would be to use two electric motors rather like the Azipod (one on each side of the spar), but they wouldn´t need to be able to swivel. That could both rotate the seastead in place and drive it forwards and backwards. The Voith-Schneider device gives you the ability to move in any arbitrary direction regardless of your present orientation however, but it might need to sit below the counterweight which might give problems with tilting due to the offset between the center of gravity and the propulsive force.
This is Carl Pålsson after registering, FYI.
Propulsion
Hi Carl,
Thanks for the links and welcome!
Personally I feel that it would be nice if a Seastead could move around or at least stay in one place without using a tugboat. Mooring is extremely expensive so it's probably not an option (unless in shallow waters of course). Mooring in the SF Bay makes a ship a "floating home", may be if it keeps sailing we don't have to pay rent? (see http://www.floatinghomes.org/dnload/fhrl.pdf for information on this).
If Seastead is outside territorial waters, it should not unintentionally drift towards land.
Btw, line breaks are inserted automatically? Just type real enters in the text.
Joep
I dont expect to make use of
I dont expect to make use of dynamic geography very often, actually. The possibility of it should do most of the work to begin with.
I know mooring can get extremely expensive, but i think we can keep it managable, because there is just so much choice for locations. We can look for shelfs, so line lengths will stay managable. And we dont need exact positioning, like an oilrig for instance, so just one line would be fine, perhaps shared between a bunch of seasteads.
In its simplest form, all we need is a block of concrete/steel/whatever, lined to a buoy. We kick that off the tugboat in the desired location, no mechanism for reeling in or anything, and you can hook up a bunch of steads. That should be constructable at a cost << seastead. Youll need a new one every time you move, but i think it would be a minor cost compared to the whole moving operation even.
But anyway, were are not yet at a point to start ruling things out, we need to consider all options in more detail.
Propulsion
Joep, thanks.
Another reason for needing precise maneuvering gear is if you need to move the seasted from within the middle of a grouping of other platforms. I seem to recall that this would be managed by lowering the moving platform so that it clears the superstructures of the neighbors and then navigating out "below" them, so to speak. Using tug boats pulling on ropes for such a critical maneuver appears difficult at best to me.
Thinking some more about possible placement of the propulsors I think they probably could sit below the counterweight /flotation cylinder. After all, the center of gravity would be situated somewhere in this region, if I understand things correctly. I guess in the end only testing will settle this. Anyone know if there has been any actual tests with models (poolstead etc), and where results from this can be found?
That PDF is a perfect example of why seasteads are needed in the first place :-).
I might have used the plain text editor last time, lets see if this will look better...
...nope, line breaks won´t play ball.
/Carl
RE: Propulsion
Regarding fossil fuels, I still think that Biodiesel brewed from algae http://www.unh.edu/p2/biodiesel/article_alge.html has alot of potential for a seastead, perhaps a solar still/furnace could provide the energy ("free" energy) required for processing.
But on the subject of "free" energy;
I recall seeing an interesting propulsion system many years ago, an inventor from a Norse nation (I cannot recall which one) had retrofitted a row boat with three outboard "dolphin" flippers on outriggers, one at the stern and one each at the sides just ahead of the midpoint. As the bout bobbed on the waves the (neutral bouyancy) flippers pivoted up and down creating forward thrust. Granted it was slow, but it was forward thrust.
I imagine that such flippers could be mounted, at the vertical fulcrum point (of the spar, so as not to "rock the boat"), on outriggers/downriggers attached to the floating dock (as mentioned in the book). Use a good ole rudder to steer and there you have it slow but free long distance propulsion. As long as you have any wave action you have a proportional forward thrust. I would still use manuvering thrusters for precision navigation (docking and the such), but given their limited use I think you could get away with smaller/weaker solar/wind charged electric motors for tight manuvering.
P.S. My line breaks, and html tags, won´t play ball either.
Station Keeping
It is extremely important that seastead be able to maintain a relative position with its neighbors. In addition, because there will likely be some solar panels on top of the seastead for daytime power collection, it is probably a requirement that the seastead not rotate while it is maintaining position. The reason for this is because the solar panels will probably have limited sun tracking capability.
While is is possible to do station keeping with three propellers spaced 120 degrees apart, we will probably opt for 4 propeller spaced 90 degrees apart. No swivel capability or rudder is required, the propellers can be fixed to the side of the seastead. This allows us to separately move the seastead in X and Y (i.e. East-West and North-South). In addition, the 4 propeller system is capable of twisting the seastead as well.
By the way, if you can find the [Input Format] and set it to [Full HTML], then this wacky forum system will insert paragraph tags around each line. The lines have to be entered without any carriage returns though. Anyhow, that I how I can get paragraphs to show up.
-Wayne
RE: Station Keeping
Regarding station keeping for the purpose of keeping the sloar panels aligned, it won't be necessary if you use the amorphous thin film panels. The thin films currently have about half of the peak conversion efficiency as the crystaline panels, but since they can convert at any angle to the sun (and partially shaded, and partially damaged, and regardless of temperature) they have a much greater overall efficiency rate. The bottom line with the thin film solar panel is, if light touches it, it make electricity.
Also great strides are being made in vertical axis windmill generators, they seem to have a greater ability to self regulate in high winds, making them less damage prone.
And I still can't seem to get paragraph breaks, what am I missing?
Paragraph breaks
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
Solar Panels & Wind Turbines
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
I agree, nuclear wouldnt be
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.
various
Station keeping/transport: Wayne, 3 or 4 propellers does sound like a simple way of getting full movement in all directions plus rotation. You should be able to do everything with three though, including rotation. I assume you mean to put them on a 90 degree angle out from the structure? You´d lose efficiency when translating with three though, but that´s the only drawback I can see. Nuclear: How about just buying the fuel? Do you forsee political problems? Eelco, yes, the possibility to move will go a long way. But that option needs to be real, and not involve high risk and cost, such as using a tug boat to move a platform from in the middle of a complex of a hundred others without ruining everybody elses day. If there is a non-negligible risk of crashing into another platform, very few will risk doing it, and then dynamic geography will fail. But, like you say reality will settle this matter eventually regardless of our argument. And, will someone for the love of all that is holy explain to me like I am a four year old how you create line breaks. I have read all your suggestions but I cant find the buttons to push or understand what you mean. Thank you.
-Carl
What about putting wind
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).
Norsk Hydro
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
links
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 :(
The R/P FLIP
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.
Nuclear Power
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.
Unfortunate...
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.
I didn't know about
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.}
Building a concrete spar
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
Oil rigs
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.
How about flexible fabric
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).
RE libertariandoc
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.
Currently, there's probably
Currently, there's probably no application of a large-enough scale, but some form of advanced ceramic may well be better for shell structures than conrecte, if more expensive.
RE: aluminim vs steel. Aluminim does corrode, it simply corrodes a nice thin film of aluminim oxide which then effectively blocks oxygen from getting further in, while steel corrodes and flakes, which makes more steel available to the air for further corrosion. However, any physical stress which is applied to the aluminum can cause the protective coating of aluminim oxide to be compromised, and aluminim is not very strong. Again, fiber glass or ceramic might be better.
Good point on the recycling of materials, but you miss a point about disposing of concrete- you wouldn't tow that back to port, you would just drop it in the ocean. Even if you had to cut away some recyclable superstructure to do so, it would cost less in fuel than you would lose in recoverable materials, and there would be no disposal fees.
Building the spar
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
Spar Erection
Andrew, sorry I totally missed your post and did not catch it until now...
I lose sleep at night at the thought of taking an 70 meter spar in the horizontal configuration and taking it vertical in the middle of the sea. It may turn out to be a show stopper. We need to get somebody who can do the structural analysis on board to tell us what is/is not feasible.
I've been thinking about this
How has it been done in the past? It seems like the launch would almost necessarily mean taking a bare shell out to an adequate depth, flooding most of it (in stages) aand then building out the physical plant and interior after pumping it dry. It would really be a limiting factor to function if the design must include a flooding process that involves most of the length of the spar on at least one side to gradually and evenlyshift ballast to the bottom.