April 18, 2012 at 4:01 pm #20077
I’m thinking that with the bottle blocks as a partly structural component (and partly floatation) maybe I should get some cheap 44gal plastic drums and add them underneath. 44 gal drums just need some structure to hold them together and the bottle blocks might work well for that.
For a while I’ve been considering setting up the bottle blocks in pillars, stacking them on top of each other, so the tops of the pillars are 1-2 or so metres above the water. This, if done properly, could help protect anything on top against the worst part of waves.
It could work well to have a 44 gal drum and the center of each pillar, surrounded by bottle blocks, and with bottle blocks over the top. The bottle blocks could protect the drum from the sun (as it’s plastic the sun is its enemy), from direct hits by waves (which have more impact on a wide/flat(ish)/solid surface of a drum than on a surface with gaps in it such as the bottle blocks). And the bottles can keep the drums in place.
I do think a hybrid approach combining many of our ideas together is likely the best solution. And combining bottle blocks with 44 gal drums might just be the perfect partnership.April 19, 2012 at 8:32 am #20104
Since you are recycling, do you think the six pack holders would be strong enough to keep the bottles together?
If they are still around anyway…April 19, 2012 at 8:33 am #20105
ugh…I cannot believe we cannot edit or preview our posts.
I was trying to point to this pic:
http://www.featurepics.com/FI/Thumb300/20061029/Six-Pack-Holder-123709.jpgApril 19, 2012 at 3:37 pm #20140
Hmm don’t think so. I think they’re designed to stretch when you want to rip your can of beer out of it, so it’ll probably stretch under wave power.
Plus cans of beer in australia aren’t all that common (though they’re available). The beer warms up too quickly from your hand. I’ve not had a can of beer for years. So I myself wouldn’t have an easy source for those plastic bits. Even pubs tend to use bottles if not direct from tap, so bottles are far more plentiful than cans.
Cable ties on the other hand are virtually impossible for a human to stretch (they get used for cuffs by cops if there are too many people and not enough normal cuffs), so shouldn’t stretch too much even under wave power. Plus you can easily tighten them if they do.
It would be good to find a free alternative to cable ties, but I’m thinking the link between the bottles may just be something worth paying for. I just need to find a cheap, bulk source.
However, those can rings might be worth adding to the soil/sand mix the mangroves are planted in. The more materials that help bind the mixture together, and help hold the roots of one plant to the roots of others beside it, the better. A bit like steel reinforced concrete, or like how hair gets used to reinforce mud bricks.
I’m thinking I’ll lay thick plastic cord throughout the mixture for this purpose. So a recycled alternative, or addition to that could be good.
Keep the ideas coming.April 19, 2012 at 8:21 pm #20152
Ken SimsKeymasterElwar wrote:
ugh…I cannot believe we cannot edit or preview our posts.
Yeah, the lack of preview sucks big time. I’ve added it to my list of things to research eventually.
I think you should have an edit function. Look at the right-hand side of the box above one of your posts. (The box that shows the date and time.) What links, if any do you have?
As an admin I can edit and do other things to anyone’s posts. But it seems like you ought to be able to at least edit, and maybe delete, your own posts.April 20, 2012 at 6:03 am #20156
“What links, if any do you have?”
No links. No edit.April 20, 2012 at 7:45 am #20159
Ken SimsKeymasterElwar wrote:
No links. No edit.
Hmm… I found the security settings and they indicate that you should be able to edit (but not delete) your own posts. But there is a plugin for roles which may be overriding that. Unfortunately it’s rather complicated so it may take a while to figure out what’s going on.April 27, 2012 at 7:26 pm #20200
I figured out one way to bring the price of cable ties down even before I find a place to buy cheap ties in bulk.
Rather than using longish ties at $3.50 per 50, and having to join them together in sets of 2 (to make them long enough).
I can get shorter ties at $1.50 per 50, join them together in sets of 3 (to make them long enough).
The result is you use 50% more ties. But it still works out cheaper. So it’s an improvement in the total cost.
Seems from my calculations (if they’re correct) to bring the price down from about $5 to about $3.33 per 9kg (boyancy) block.
Now if I can find a place to buy them in bulk I should be able to bring it down even further.
The downside of using the shorter ones is its a bit more tedious, because you end up with 3 joins and need to line them up so they are located in the gaps between the bottles rather than being where the bottles touch.
I think it’s worth it because once you get the hang of it it’s not that bad, and worth the cost reduction.
Btw I’ve just about completed 3 blocks (2 are done and one almost, but ran out of ties) of 18 standard small beer bottles each. Same shape, etc.
They don’t have as much boyancy but they’re plentiful (plenty of people I know regularly get cases of 24 bottles at a time) and I have collected a whole stack of them ready for when I have more cable ties.
I’ll be using these smaller bottle blocks in the middle, with the bigger ones around the edges to spread the boyancy as wide as possible and increase stability.
I’m also thinking of filling the necks of all the bottles with ship grade silicon, under the caps, to help ensure they don’t fill with water.
And I’m also rethinking whether to put the whole thing straight into the ocean (which is within walking distance, but not easy to drive to with all the blocks).
I’m thinking I might see if I can get help to take it all to an estuary nearby (a 15-20min drive) to put it in, at least until the mangroves and other plants take hold and help ensure it all stays together.
I guess I’ll decide as the time gets closer.October 4, 2012 at 7:51 pm #21112
I’ve made a few more blocks now.
It takes time to collect the bottles and the cable ties and so it’s a slow process so far.
After making the last block I counted them all again….and it seems I have 11 blocks all up. (Though it was tricky to count because they’re stacked up…kinda out of the way….but I think I counted right).
So with 11 blocks, each having roughly 9kg of buoyancy each (if I recall correctly from when I tested the buoyancy of a single bottle)…..I should be at about 99kg in total (11×9 = 99).
That’s enough to handle my weight….so long as I don’t have much gear with me.
Though with only a little bit of spare buoyancy I’m guessing it’ll be unstable….if I’m anywhere except dead centre.
I also have 2 water drums (guessing 20-25litres each, so 20-25kg of buoyancy each, maybe more if they hold more), plus a bunch of plastic bottles I’ve collected (most are 2l). So I figure I should be able to get the buoyancy to around 150kg plus once I attach them.
I’m also considering getting some plastic (approx) 44gal drums to attach….to increase buoyancy and stability (they range from between 150kg and 200kg buoyancy each).
So I might not be far off a deployable prototype….which I can camp on. Still kinda making it up as I go though….so never quite sure how it’ll turn out.October 4, 2012 at 7:59 pm #21113
Thought I’d add…..(thinking out loud)
When comparing the tediousness of binding the glass bottle blocks together (it’s not difficult….but fiddly), and the buoyancy they provide, vs. that of using large plastic drums…..it could seem like the glass bottles aren’t such a good idea.
But……considering that if using plastic drums alone…..I would need to then build a platform structure on it….which would have its own issues (such as timber rotting, steel rusting, etc.)…..
I think if I treat the glass bottles as mainly a structural component (ie. they are solid and upside-down provide a good platform, without any other structure required)…..then they make sense to use.
So while the glass bottle blocks float….and provide buoyancy…..I think their main role is structure and platform. Nice to have a structure which, in itself, floats.
I figure then I’ll add extra buoyancy using plastic drums…..to bring it up to a good level.October 4, 2012 at 8:09 pm #21114
Another thing I should mention.
When using the bottle blocks upside down (to provide a flat-ish platform on top) the tops of bottles are maybe a bit vulnerable if I accidentally run the platform aground (shouldn’t happen…..but the titanic shouldn’t have sank either….gotta prepare for the worst).
Plus…..I figure….while each block is solid (so solid when I dropped one on hard concrete from standing height it suffered absolutely no damage at all)…..if I connect lots together to make a platform which is wide…..the biggest issue I see is the leverage which could be gained by waves twisting the whole platform.
So…..to solve both of these problems (to an extent)….I grabbed two bottle blocks….sat one flat on the ground (necks up)….and another one upside-down on top of it.
The necks of one block fit perfectly between the necks of the other block.
This means there are no bottle necks sticking out….and both top and bottom side of the dual-layer blocks…..are flat.
Plus…the double thickness of the platform reduces the chance of twisting being a problem.
The downside is if I double up the platform thickness…..I pretty much half its total area. But I think it’s a trade worth doing.
Also….if I stagger the blocks (like bricks in a building are always staggered)…..then each top layer block helps ensure the bottom layer blocks stay together…..and vice-versa. In this arrangement, the interlocking necks seem to actually become and advantage.October 4, 2012 at 8:16 pm #21115
I do still need to figure out the best approach for sealing the bottles though…..which will likely be either…..or a combination of both….marine grade silicon….and rubber (from old tire inner tubes) and/or pond liner plastic over the top.
Pretty sure I can get a combination of those to solve the problem.
The only other real issue I need to sort out is how to ensure each block is solidly bound to its neighbours….but I think it’ll be partly just more cable ties (using the same approach as within each block itself)…..and using the interlocking double layer….of staggered blocks….to help keep them together.
Eventually plant roots should eventually add strength…..and I figure I’ll assist that by adding coils and stuff of thick plastic cord…..which the plant roots will grow around….to help keep the entire structure together.
I don’t see any reason to think the prototype shouldn’t work. Just might need to keep adding more blocks to increase stability….and or adding extra plastic drums/bottles for extra buoyancy….which is just a matter of time and putting in the effort.November 23, 2012 at 2:43 pm #21487
I found an interesting example of a structure made from living plants:
Basically I want the majority of the structural strength of the stead to come from living plants, with their roots binding all the bottles together. This way if any part of it gets damaged, as long as it just manages to kinda stay together, then it should be able to repair itself by the roots filling the gap.
Also it means if the cable ties deteriorate after a while (which they will one day, just hoping they last for at least 5 years, and ideally at least 10) then it won’t matter. Spiral island had huge mangroves growing after just 2 years if I recall….so 5 years should be plenty of time to get some significant strength from the living plants.
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