Breakwater Design


#81

Please note, I’m limited in my own ability and using out-of-date software and this is about the best approximation I could do. The new pdf specifies that the space between the spars is determined by the size waves to be dissipated, as well as giving the calculations.


#82

There’s three important differences. Their approach uses the diagonal tension lines to move the wave energy down to the seafloor, you approach shifts it to another spar. They have steel (or whatever metal) as guy lines in tension, you have substancial metal braces between the spars in alternate tension and compression. Their approach is fairly unrestrictive to boats, but your horizontal top connectors impede boat traffic. You must have adequate floatation somewhere to hold up the horizontals.

I suspect they will have many snapped guy lines after a storm, and your system will be intact. As for boat traffic, i say “somebody build both and lets see how they function in real life!”.

I admit that previously, i did not realise the triangular structures in your drawings laid flat at the surface.


#83

The spreaders can be buoyant, and were designated as such, in that particular patent. Not hard to run lateral rebar through a cast buoyant float, the spreaders can be below the surface, just not several fathoms. I think 1 fathom would suffice, for the majority of craft, anyway, while buoy markers can designate maximum draft over the breakwater and the channels at the same time.


#84

Hell, for that matter, use short spar-buoys, laid horizontally, tires included, as spreaders.


#85

It crosses my lil mind that you might find a way to make the connections to the spar tops generate air or hydraulic power. So as they push and lean they operate cylinders. Could do the same with the guys to the sea floor i spose.

Hmm, thinking a few moments more, it also crosses my mind they show only 2 diagonals to the bottom per spar. Should be at least 3, maybe 4, and that will cause some contact with adjacent guys.


#86

That’s part of why I thought the tension-leg would work better, with physical spreaders at the top.

Break the subsurface power of the wave and the surface collapses. You don’t have to have a barrier to the top. Most lagoons have subsurface reefs that act as breakwaters.


#87

But if the boat hits one spar, every spar connected to it horizontally must also move.

Actuall, with either approach, getting dropped atop one will probably hole the boat, so nevermind! :slight_smile:


#88

That’s why I added…


#89

I’m a bit slow today, power went out at 2:45am, electronics were affected, i went to town for steel price list, picked out some poly 33gal barrels and took them to local Marine Police for evaluation and approval as boat bits, visited recycling center, and got a few groceries. I crashed at 5pm for a few hours.


(Gordon Hoffman) #90

As I mull over the ideas that I read about, and think about the (our) objectives, I think that these breakwater devices should also be generating energy (sort of which Adrien was saying), so I imagine the water being directed in to the breakwater device and being lifted like a ram pump does, from which the water could run through turbines. Of course, the device would store a great amount of water which would also give it a lot of mass. So instead of hydraulic cylinders there might be large diaphragms that act as squeeze tubes used to lift the water. I"ll have to do more drawing and envision its function because I know it will have to be of reasonable cost (unless it can pay for itself in energy revenues) and be easy to maintain.


(Nick Gencarelle) #91

I like this design seems inherently functional. This allows for waves to go over and around. Any underwater creations need to be built as one would an aquarium with varied holes for different fishes to hide and breed as well as crustaceans, and accelerating the growth of corals around the perimeter by stimulating an electric current from solar and wave power in buoys.


(Nick Gencarelle) #92

The water would not have to be stored just used. Hydraulic accumulators can store the energy.


(Nick Gencarelle) #93

Nice - Ultra high strength concrete and the new amazingly strong glass options make this very doable now.


(Wilfried Ellmer) #94

yes, doable technically but not on land where codes inhibit the cutting edge concrete engineering as “non code conform” …


(Nick Gencarelle) #95

Concrete needs to meet OR exceed the standards.


(Wilfried Ellmer) #96

concrete codes where written with heavy method in mind - they can only very limited be applied to concrete composit technology…


#97

Some more thoughts…

-I don’t believe you could scalably resist wave buoyancy with bottom anchoring without unafforable and unmovable see floor engineering: Forces are simply much too high.

-I don’t believe massive floating seawalls could resist to even medium size wave. 3m wave= static 3ton per seawall length + God knows how much dynamic “water hammer” pressure.

  • Big tankers and cargo ships can reach their strength limit due to the longitudinal bending moment when facing big waves THEY chose to face. An immobile structure doesn’t have this luxury: Streamlined bows only divert the wave impact on the bow, they don’t cancel the waves acting on the hull behind.

  • I still believe that the only reason why floating cities don’t exist today and main challenge to make them exist tomorrow is that they reside on a 2D surface where solar power gets concentrated in the form of mechanical energy. Nowhere in the solar system is a place so far from equilibrium (okay maybe the surface of the sun :-)) and so dense in power.

  • Just imagine that the only long term structures in the open ocean are oil drilling and handling platforms and with a 50x50m floating surface, those guys surface can supply half a continent with power…

  • I think our key tech is flexible couplings capable of handling say min 30MW per 50x50m platform in a storm…
    http://www.ewp.rpi.edu/hartford/~ottj/ET/Other/Wave%20Energy%20Sources/1.http___www.seafriends.org.nz_oceano_waves.pdf

Without that I don’t see this project being other things than a billionaire’s dream or a floating “Dubaiesque” Disneyland…

Any thoughts?


(.) #98

I like the term floTing Dubaiesque Disneyland


#99

What if…?

Instead of breaking the forces, we redirect them…?
Use a combination of a Gregorian Collector and parabolic reflector, something like this…

…or this…


What about the waves!?!
#100

I agree, breakwaters are a waste of money and time not only because they might fail in big seas, but also because:

  1. In a coastal location already protected (Fonseca Bay, for example) a breakwater is not needed. IF you build a 30’ high breakwater around a seastead already located inside Fonseca Bay, it will be hot as hell inside that enclosure since the breakwater will block any wind cooling that location.

  2. If the seastead is located offshore in (lets say) 1000’ water depth it will cost $ millions JUST TO ANCHOR the breakwater, and it will still float up and down on the long swells. Useless,…

Obviously, whoever thought of breakwater and deemed them somehow “necessary” for seasteading never spend a minute at sea,…