This topic contains 42 replies, has 5 voices, and was last updated by  CompulsiveCoder 2 years, 9 months ago.

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• #19531

CompulsiveCoder
Participant

I’ve started a very early, small scale experiment, to see if I can create a largely recycled seastead.
My plan is to create a basic raft to grow mangroves on (long before its big enough even to stand on), then use those mangroves as a construction material.

I’ve seen people using plastic bottles and while I think it has potential, the use of plastic has many issues that I won’t go into here.

For the first experiment I wired together a stack of recycled glass wine bottles, then bound the whole stack together with cheap plastic cable/cord.

Each 750mill glass bottle has a minimum of 500grams of boyancy (ie. it’ll hold 500 grams above the water) according to some simple tests and basic maths. That’s taking into account the weight of the glass itself (when submerged).

The first experiment has a minimum boyancy of 6 kilos. I’ve labelled this first stack of bottles a “brick” because the goal is to keep creating more of them and connect them together.

A few of the benefits of using glass bottles:

– The glass bottles, when connected together properly, become structurally solid. This means there’s no need for a secondary structure to make the whole thing rigid.
I showed the first brick to a builder and he said he’s surprised how solid it is.
I dropped the first brick accidentally on concrete and it did no damage at all. The bottles are still rigid. They didn’t even budge out of position.

– They’re free and easy to come by. Myself and people I know drink more beer and wine than soft drink, so it didn’t take long for me to collect enough bottles that I can now probably make at least 5 more of these bricks.
If I want to scale up I’ll go to the local bars/pubs and take bottles off their hands.

– They’re totally inert and will never leach toxins or become a pollutant.
Even if the bottles were dropped to the bottom of the ocean they would cause no problems at all.

– The heavy glass has more inertia than plastic and so the waves have far less of an impact than relatively light plastic.

– Using bottles means there’s no solid face for waves to push upon (like the side of a boat). Waves can flow through the gaps between in the bottles with a relatively small amount of kinetic force.
If a wave lands on top of the seastead the water can run through the gaps and so won’t sink it.

– The weight of the glass bottles at the base of the seastead lowers the centre of gravity, unlike plastic bottles which are likely to make a seastead top heavy.

– By flipping the brick upside down the bottoms of the bottles provide a relatively flat surface on top of which containers of sand can be placed and plants can be grown.

– Open bottles bundled together below the seastead become a good habitat for fish, which improves the fishing nearby.
These will also ideally be used as part of the anchor, forming an artificial reef.

I used wire for the first brick with the goal that it should last at least a few years, until the roots of the mangroves take over their job.
I’ve actually decided to switch to cable ties for the next bricks because they’re easier to use, and should last longer.

So each bottle will be cable tied to the next, and each brick will be also bound in plastic cable/cord, to be absolutely sure they’ll never come apart.
The bricks will be bound to other bricks with more cord, resulting in more strength than is actually needed. (It’s good to have a margin of error.)

Using this approach the only costs for the basic raft is cable ties and plastic cord. Each only cost a few dollars for multiple bricks, and I can keep buying more as I have more spare cash.

It means there’s no major cash outlay and I can keep making more bricks over time.

If anyone wants photos of the first brick let me know. I’ll see what I can do.
I’ll be making more once I get a stack of cable ties.

#19554

Elwar
Participant

Good job getting started with experimenting. Glass is an interesting material to test. I suppose it should last in salt water, but the obvious question would be durability. Huge waves crashing against something over and over needs to be durable.

This could definitely be a great option for a cheap platform in steady water or behind a breakwater.

I like the mangrove testing. I am curious to see how long it takes for them to grow. Where are you growing them? Saltwater?

#19555

CompulsiveCoder
Participant

The shape of the bottles and the thickness I believe does make them incredibly durable.

If you get a flat piece of glass and hit it, it’s easy to break. I believe this is partly because that impact causes tension rather than compression.
Glass doesn’t have as much tensile strength, like concrete (ie. you pull it from either end and it’s not as strong as when you compress it).

Glass does however seem to have a lot of compressive strength like concrete, and the shape of the bottles causes the energy of any impact to result in compression of the glass, kinda like pushing downwards on an archway, which spreads the load all the way around it, and every aspect of the arch/bottle is under compression.

The only way to cause a large amount of tensile strength on a bottle would be for the impact to come from the inside, which will never happen in the ocean.

Admittedly I’m no expert and much of this is theory, but I think it holds up.

One concern I had was what if the bottles repeatedly hit each other. Even though I think they’re strong that could eventually result in weaknesses, small cracks, and end up turning into breakage.
One way to address this is to put tension into the cable/cord that holds them all together, and ideally be able to increase the tension every month or so as the materials naturally stretch. This way the bottles are never loose enough to clash.
Note it’s the cable being tensioned (not the glass), resulting in further compression of the glass. The plastic cable/cord, like wire, has a lot of tensile strength, unlike the glass.

The Sydney Opera House uses this technique of running cables inside the structure to tension it to the ground. This results in the concrete being under constant compression, which allows the arches to lean and the structure remain solid.

Using a combination of glass and plastic cord/cable is kinda like reinforcing concrete with wire/steel. It results in something similar to tempered glass and tempered steel.
When you temper glass and steel you end up with both tension and compression in the same package (tension around the outside and compression on the inside). This means that far more force is required to first counteract the tension or compression, then even more to actually break it.

I suggest reading up on tempered glass and steel as the concept is quite useful. Even tempered chocolate uses the same technique I believe.

As for the mangroves I’ve not yet started growing them.
I was planning to try it in an estuary but I’m closer to the coast (within sight and walking distance) than an estuary, so I’m thinking of biting the bullet and putting the first experiment out just past the breaking waves.
The low cost of the experiment means that even if I lose it it’ll be worth the learning experience, to know that the next experiment needs to be stronger, and/or better anchored.
I think the total cost (excluding time) for the first experiment will likely be less than \$50. That’ll include a few “bricks” and a DIY anchor, as well as the cable to anchor it.

I’m thinking of lining the top and sides of the “raft” with tin cans full of sand, and plant mangroves in them. Hopefully the mangroves will get established before the tin cans rust away.
As far as I know it rusting metal is not a pollutant, and using food grade tin cans should mean I can be sure there’s no toxins.

I’ll certainly let you know how I go with the experiment, but it’ll take time to get the materials organised, put it together, and set it up.

Btw I saw a video on mangrove farming and apparently you can start harvesting some after only a couple of years. Then keep re-harvesting every year after that. And because they’re resistant to salt water they’re ideal as a structural material on seasteads.

#19775

CompulsiveCoder
Participant

I just made another brick using 18 bottles and cable ties instead of wire. This should have a minimum boyancy of 9kg (ie. it’ll hold 9kg above the water).

It was a lot simpler to put together than using wire. It should last longer than wire. And I can keep tightening the cable ties as needed.

I first used two sets of cable ties (a set being two joined together to make them long enough) to join bottles together in clusters of 3. Using two sets makes it more rigid (one set near the top and one set near the bottom).
Then I placed the clusters of 3 bottles together to form the hexagon with a space equivalent to one bottle in the centre (making it possible to reach in and handle the cable ties).
I used the same approach to bind each bottle to every bottle touching it (again in 3s). So now when you look at it you can’t tell the difference between the original clusters of 3, and any other 3 bottles side-by side, because they’re all bound using the same approach, to ensure no weak spots.

I can now pick up the entire brick of 18 bottles by one single bottle, or even by a cable tie, and the whole brick seems structurally solid no matter what angle it’s held, or how much you try to twist it or pull it apart.

I’m quite pleased with how effectively this is working. I’m not going to need any additional structure to keep the whole thing ridgid.

Here are the numbers…
I bought two packets of 50 largish cable ties at \$3.50 AUD each pack (from one of those bargain stores). So 100 cable ties for \$7.
I probably used 1.5 packets all up (approx 75 ties max I’m guessing, though I didn’t count them) so the cost for the 9kg (boyancy) brick probably cost no more than \$5 or \$6 (excluding my time).

Now I’ve got the hang of it I’m fairly sure I could build each brick in under an hour. Though the first one was slower because I was still trying to figure out the best way to do it.

So in two days, given enough bottles and cable ties, I think I could build a raft able to hold my weight.

The cable ties weren’t quite long enough so I ended up joining them in twos and using them like that, which meant I used twice as many as I theoretically could.
I’ll look out for longer cable ties next time and hopefully I can buy them cheaper in greater quantities. This should bring the price of each brick down even further.

Even using this price and these numbers it should be possible to build a raft capable of holding 90kg above the water, for under \$60.
Considering I weigh less than 90kg (though not by much) that should be sufficient to hold my weight.

Ideally the raft should have twice the boyancy that I need, for a big margin of error, and to improve stability. So I think for \$120 I should be able to very easily, and quite safely, hold my entire weight, plus maybe a tent or something.

I am planning on covering the whole thing with sand and plants so I will need to take into account the weight of those. But still….even with the sand, etc. on it the whole raft will be only a small fraction of the cost of a standard boat or barge.
And I’ll bet it’ll be far more durable too, requiring less maintenance.

I think I have enough bottles for at least a few more bricks but I need to get more cable ties. Now I know it works I’ll be looking to buy in bulk.

I’ll keep the forums posted.

I’m keen to get feedback on this, especially to do with comparing the costs/boyancy that I’ve outlined, with other methods of building seasteads.

Even if someone does use another method to build a seastead, this approach using bottles could be a good addition as breakwaters, as habitat for fish and plants, etc.

#19776

CompulsiveCoder
Participant

I’ve been thinking about how to deal with the massive amount of potentially destructive wave energy in the ocean, especially when it’s rough.
If not dealt with properly the wave power can be potentially a huge problem. But it is wave “power” and the key word “power” holds the clue IMO.
The power shouldn’t simply be defended against, it should be harnessed.
So I’ve been thinking of this…
Line the edges of the seastead with a whole bunch of really cheap plastic buckets (70cents each last time I bought some) or recycled buckets/drums if I can get them, flipped upside down (so the opening points to the water).
Drill a hole in the base of each bucket big enough to attach cheap 13mm gardening pipe (approx \$4 per 20m if I recall) using a cheap fitting with rubber washers, then join them all together into a single set of two pipes via two x one way valves (one in, one out).
The result should be that any time the waves rise they push the air in the buckets through the pipe causing quite high pressure, then when they fall they cause suction in the other pipe.
With a pipe containing high pressure air and a pipe containing suction, you have yourself a source of virtually non-stop energy.
This energy could be harnessed by having the pressure pipe release through a turbine to produce electriciy, or release into a drum under the seastead to push salt water up through another set of pipes to water the mangroves, or to spray the salt water into an evaporation chamber to distill fresh water and produce sea salt, or any way you can think of to use air pressure.
Not only is this a source of free energy but it also acts as shock absorbers, so waves energy is absorbed then dispersed steadily over time instead of repeatedly hitting the edge or the bottom of the seastead in focused impacts.

It might even be possible to use the energy to counteract the directional force of the waves. So when the waves hit the east side you use the energy to suck in water on the east side and pump it out on the west side of the seastead, or to drive a propeller, so the seastead effectively swims into the waves constantly, reducing the tension on the anchor.

I think a ring of floating breakwaters around a seastead which use these techniques could be used as a floating harbor, and keeping the water relatively calm inside the harbor, around the more advanced/expensive parts of the seastead, and the living quarters.

I’m keen to get feedback on this idea too.

#19783

Elwar
Participant

Just a quick question…how are you sealing your bottles?

Glass should hold up long term to saltwater but any type of metal or plastic will be gone within a year.

My cheap grill fell into the canal about half a year ago and instead of pulling it out I kept it in just to observe how long it would take for it to completely dissolve. It is certainly rusted at this point and not all there. Most likely within the year it will not resemble a grill anymore.

Considering you do not have too much pressure against just the tips, I would suggest mixing a very wet batch of ferrocement and just dip the ends in it to at least coat the metal part. That could work.

I try to think of seasteads as something that should last close to 100 years. Maybe this is a poor assumption with such a new concept.

#19788

CompulsiveCoder
Participant

Very good question. I’ve thought about it a bit but I probably need to think about it some more.
They’re wine bottles with fairly sturdy screw caps but they are some kind of metal so the rusting will need to be addressed.
I did start consider maybe coating them in ship grade silicon or something.

I should probably go grab a bucket of sea water and stick one of these bottles, or just the cap, in it to see how long it lasts.

I also considered filling each bottle with some recycled newspaper. This way if they leak and water gets in, the newspaper will start to break down, produce gas (carbon dioxide and methane I believe are likely the primary ones), and ensure that the water is pushed out.
Considering that the bottles will be upside down, even without any caps there should only be minimal amounts of water getting in (due to the air inside keeping it out). So the paper should take a long time to break down and therefore provide years of slow release gas, constantly topping it up.

I’ve also considered trying a whole stack of bottles with no caps, upside down, but with very thin piping running into it, all connected to just a few centralised pipes.
Then I can use wave power to push air into the bottles, or open a valve to let air out of the bottles, to control the height of the seastead. In good weather I lower it down so I can sit on the water’s edge, with the water lapping at my feet when on the lower parts of the seastead, and in bad weather I use the wave power to raise the whole thing up higher to avoid the waves.

I think some experimentation is in order.

#19789

CompulsiveCoder
Participant

I should probably point out that the bottles with no caps (if I do it) would be in addition to all the sealed ones, obviously. I think it would be unwise to do an entire seastead without the caps and simply hope that the air inside will keep the water out. Theoretically, under the best conditions, it should work. But it’s when unexpected things happen, such as big waves rocking or tilting the seastead, that this theory might break down.

#19790

CompulsiveCoder
Participant

A mistake I realised in the numbers I presented earlier.
I didn’t include the cost of additional cable ties (or whatever material I need) to bind all of the bricks together to other bricks (only the cost to make the bricks in the first place).
Still….I figure that extra cost should still be less than the cost of the bricks themselves.
I’ll need to experiment to figure out exactly how many cable ties etc. I need to bind the bricks together to work out the numbers.
Even \$200 or \$300 total cost for a seastead I can camp on with a tent is till a pretty good deal. Or that I can start a mangrove farm on to produce building materials for the seastead.
Imagine taking the standard price people pay for a smallish boat (\$1,000 to \$20,000 and beyond), and putting all that money into a recycled seastead.
It could end up 10 times the size of a boat of the same price. Admittedly the seastead is not going to move very fast through the water but that’s not my primary focus.
Also, even if half of the seastead’s floatation is destroyed, or removed, or leaks, the other half should still keep things afloat.
Try ripping a hole in half a boat and see what happens. I think we can skip the practical test and simply look at titanic :p

#19793

Elwar
Participant

“Even \$200 or \$300 total cost for a seastead I can camp on with a tent is till a pretty good deal.”

It sounds like that is the initial goal of many of us here for our prototypes.

It would be interesting to see if the Seasteading Institute could put up a challenge of paying \$1,000 each toward potential applicants to make a seastead that is good enough to spend the night on with a tent.

Then they can designate a judge to go spend the night at each of these seasteads and rate them and give the winner/s a prize.

It would probably kick a few of us into high gear to get something going by this summer.

#19810

CompulsiveCoder
Participant

“It would be interesting to see if the Seasteading Institute could put up a challenge of paying \$1,000 each toward potential applicants to make a seastead that is good enough to spend the night on with a tent.”

Definitely, that would be good.

I think it would be even better if done in phases.

First phase:
Deploy a small proof of concept that can scale up, that holds maybe a minimum of 10kg above the water.
Then the first 10 viable prototypes are chosen and each are given \$50 to go into materials.

Second phase:
Deploy a slightly larger proof of concept able to hold maybe a minimum of 50kg above the water.
Then the first 10 viable prototypes are chosen and each are given \$100 to go into materials.

Third phase:
Deploy a larger proof of concept able to hold a miminum of 100kg above the water.
Then the first 10 viable prototypes are given \$200 to go into materials.

Fourth phase:
Deploy a larger proof of concept able to hold 1 person camping comfortably overnight (in moderate weather).
Then the first 10 viable ones are given \$500 to go into materials.

Fifth phase:
Deploy a larger one which two people can camp on, and can have a small bbq on to cook (ideally fish caught from the raft).
The first two to do that get \$1000

It could keep going up and up with greater and greater goals and rewards.

Most of us would likely just gradually increase the size of the prototypes until it’s large enough, rather than building new ones from scratch.

If the first competition is announced then give me a week, and I’ll have one in the water able to hold 24kgs. (One brick with 12 bottles and two bricks with 18 bottles each.)
The only real hurdle I have is figuring out the best way to anchor it. Everything else, in terms of a short term proof of concept, has already been figured out and mostly completed.
Long term might be slightly different in that I need to make sure I can stop the bottle tops from rusting away. But that’s a matter of experimenting with it.

I really would like to get the first prototype in the water and hang a fish trap from it, to catch myself some food. The only concern I have short term about it is someone coming along and removing it, stealing it, or destroying it. Or about the anchor coming loose. I figure I’ll use at least 3 anchors.

Everything else is pretty much sorted, and can be finished up in just a few days (and not even full time days).

#19816

CompulsiveCoder
Participant

The best thing about running that competition is that you would then most likely have a minimum of 10 viable seastead concepts, all built with minimal up front cost, and so others can grab all the ideas and use the ones that they find the simplest and cheapest to implement.

It’s all well and good to have CGI designs of multi billion dollar floating cities, but what is actually needed is practical, low cost solutions that anyone can set up, on their own, with minimal expertise, and minimal funds.

Seasteading will only be taken seriously IMO when it’s not only rich people who can do it.

#19821

CompulsiveCoder
Participant

Just had a thought…in terms of protecting the metal bottle tops…
Get old tire inner tubes and cut them into strips. Wrap the strips around the neck of the bottle (below the metal, not over the whole thing). Then get durable plastic, like pond liner, cut it into squares (or circles if you could be bothered) and wrap a few layers of it over the entire top covering all of the metal, and all the way to the rubber strip.
Then get a cable tie and tightly wrap it around the plastic where the rubber is underneath it. The rubber will squish down to help form a good seal, and the plastic covers all the metal with the cable tie making sure it never comes loose.
A square metre of plastic should do a lot of bottles, and so it should be fairly cheap.

There’s my last major issue solved. Ok bring on the competition.

#19822

CompulsiveCoder
Participant

Still trying to decide whether to try making my own anchors, or whether to just buy some proven ones.
Either way I’ll deploy at least 3 anchors then drop bundles of open smaller bottles (bound the same way the floating ones are) attached to the ropes, so they slide down the ropes and sit on top of the anchors, keeping them in place, and turning into an artificial reef.
The anchors and ropes will keep the bottle bundle reefs from moving too much, so they can be a reliable habitat for critters, which become food for the larger fish, which become food for me.
I might fill a few of the bottles with sand just to help weigh them down. Critters can still live in the bottles, and dig into the sand.
I’ll just need to be careful swimming there because it’ll be an ideal spot for sharks to feed. So I’m thinking I might need to float a netted section which I can swim in. It can be held up by a ring of plastic piping which is joined at the ends to keep air in and water out, making it float. After all a net weighs next to nothing.

#19897

CompulsiveCoder
Participant

Just completed another 2 bricks/blocks, each with 18 bottles.
I ran out of empty recycled glass wine bottles so now I started on empty recycled long neck beer bottles. I’m presuming at this point (though need to do some experimenting to be sure) that the beer bottles have roughly the same boyancy of 500grams each.

So now I have:
1 x 12 bottles = 6kg
3 x 18 bottles = 3 x 9kg = 27kg

A total of 33 kg of boyancy. (ie. it’ll hold 33kg above the water, if my tired brain has crunched the numbers properly)

I’ve got the hang of putting them together and I think I can probably put together a brick in about half an hour. That’s a guesstimation though because I didn’t time it, and it’s hard to judge time when I focus on doing something.

I’m running out of large bottles though, so I might have to get serious about collecting them and asking people to collect them for me.

I guess I should start binding the smaller beer bottles together soon too, which will remain open, and be primarily intended as animal/fish habitats. Some will be hanging just under the raft/seastead and others will sit on the ocean floor, on the anchor.

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