Breakwater Design


#141

If something like this was weighted so that 1/2 the wave rides over the top as the rest passes under, creating lift in direct proportion to the mass in top, it should work as a breakwater.


#142

Wind and wave platform. Looks like it can also work as a floating breakwater…

http://www.floatingpowerplant.com/


#143

Wave Dragon floating platform…?


#144

The problem with redirecting a wave’s force like in that pretty illustration is that
redirecting huge forces requires enough mass, structural strength and/or attachment to the planet. Without those, this pretty device will be pushed around and tossed like a beachball by any serious wave!

This device purports to redirect the wave’s (enormous, sudden) force from horizontal to vertical – increasing the magnitude of the forces that the “breakwater” must withstand by roughly 40% (sqrt(2) - 1, from vector math.)

Redirecting forces is perfectly possible – with proper engineering. Unfortunately, this design lacks such. Expecting a device to withstand large-storm-wave forces, in both the horizontal and vertical directions – while supported only by vertical cables – indicates too many cartoons and not enough Physics. Sorry, but I’m not going to sugar coat the reality.


#145

In other words, it needs to be sturdy and anchored, but capable of having some added slack to allow for larger wave motion, unless, of course, you plan to avoid locations prone to typhoons and hurricanes…

Gotcha.

You’re saying that, almost any place on this map, that is ~sea-foam green, it should be OK…

(Mildly modified version of the NOAA chart of all known typhoon activity in recorded history)


#146

Again, this shows the ramps scooping water off the top of the ocean as if the wave is a mass moving horizontally across the surface of the ocean. Please show in pictures how the water gets from

(faculty.gvsu.edu/videticp/wave_dimensions.GIF)
to being up high on those ramps. Hmm, editing to not post the pic twice…


#147

Hey JL,

Would you kindly post a link to the original?

I’m not expert enough about waves/storms/sea-state to pronounce safety equals those sea-foam green regions, since big waves can come from sources other than typhoons.

However, staying out of the way of typhoons, until some truly brave souls pioneer seasteads in rough, open water sounds like more my personal speed. Or finding/licensing/leasing a shallow-enough place that a conventional breakwater could be built, without breaking the bank.

I’m not saying that seasteads cannot be designed to take big waves; I’m saying that big-wave-robust seastead designs will require large, carefully engineered structures, and we can’t just “wing it” with fancy architectural renderings.


#148

Same link I posted in the undersea cable thread, ~2 weeks ago…

https://www.climate.gov/news-features/understanding-climate/tropical-cyclone-tracks


#149

Something like this… It’s anchored, or ballasted against the wave action, not some free-floating pontoon.


#150

Draw a couple of lines. It shows the ramp is below the trough, and the top isn’t all that far above the average water-level.


#151

That’s more like it!
Though the chains or cables – and whatever those connect to – must be able to take mondo transient forces, repeatedly, for a working lifetime of decades. Because really strong moorage connections would be needed, I think this approach is most likely to work in relatively shallow waters. (I’m guessing no more than 50 meters deep, probably much easier at no more than 30 meters deep. Just my guess.)


(Jonas Smith) #152

RE: Wave Dragon…it is designed to act like a beach, causing the wave to break and overtop the rim…

Here is video of it in operation: www.youtube.com/watch?v=r7-EPR8Ss6M

It needs to be in an area with decent waves, though. If the waves don’t have enough energy to overtop the wall and reach the reservoir then you won’t get any energy. I’m also not sure how well it works as a breakwater…from the video it doesn’t look like there is a calm patch behind the device but it’s very small so probably not a good test.


(Jonas Smith) #153

From the Wave Dragon Specification page:

Mooring system

The mooring system is a vital part of the Wave Dragon concept. It doesn’t just moor Wave Dragon to the sea bed but is designed to interact and indeed counteract with Wave Dragon in order to reduce the forces in the mooring system and to fix the wave reflectors.

Flexible wires are used on the Nissum Bredning test prototype as the low water (6 m) would eliminate the positive effect from a slack moored system.

From the Wave Dragon Principles page:

Stationary: First one has to imagine the Wave Dragon moored (like a ship) on relatively deep water, i.e. more than 25 m and preferably +40 m to take advantage of the ocean waves before they lose energy as they reach the coastal area.


#154

Pretty poor video, pretty sure i don’t want packets of high voltage arcing entering my house every 5 seconds. They spent as much time on disinformation as information. Like the continual start-stopping of the turbines in the animation.

Anyhow… so for wavelengths of 300ft, you’d want to build a 300ft beach from the surface out to 150ft deep?

There’s no news of the company or their machines after 2011?


(Jonas Smith) #155

Well the prototype uses seven turbines which, according to their website, “individually start and stop in order to facilitate as smooth an electricity production as possible.” Yea, I don’t buy that either. You’d definately need to combine this with an energy storage system rather than just plugging it into the grid, because no matter how smooth you try to sync your turbines you’ll never get a constant flow of electricity.

Well the larger Wave Dragon devices do get pretty big. For locations with very high wave energy you are looking at 390m x 220m size and a 200m wave reflector width, with a 14000 m^3 reservoir. So yea, a pretty big “beach” for those big waves.

Well there was some info presented at the ICOE 2012 where they were discussing the larger 1.5MW design that was to be installed at Hanstholm, and there was discussion about continuing to analyze the device using engineering software. But as far as I can tell nothing new has been put in the water since 2011.


#156

LOL, it looks that it’s gonna cost more to build the damn breakwater than the actual seastead…


#157

Personally, put the seastead ON the breakwater, as part of the structure, itself. If it has a central zone, there’s your aquaculture pen. Set it with a bow and a recessed stern, as a set of boat docks., like your module, only much larger. Line the port and starboard sides of the prow with wave-energy converters, like the variable ballasted floats that operate hydraulics, to generate electricity.


(Chris) #158

Putting the seastead on the breakwater doesn’t solve the mooring expenses does it? Wouldn’t you still need the seastead moorings to handle the same forces? I suppose that the larger area of the seastead with added breakwater would help mitigate the waves affect on the seastead, but wouldn’t the forces on your moorings still be the same or even worse now that both are sharing the same moorings? I like the idea of using the breakwater to produce energy as well, to help justify the additional cost. Would making the seastead part of the breakwater eliminate modular seasteads? What would the wave forces wind up doing to the connections between modules? The more I think about breakwaters, the more I don’t want to think about breakwaters.


#159

As an integrated structure, surrounding a sea pen, generating electricity, forming a foundation for a seastead, with a smooth-water slip-stream for docking, I think it’s going to be built modular, to begin with.

Wave-energy converters aren’t the most productive generators, but with one demo-model, there were some 14 floats that created enough electricity for 12 homes.

I’ve already described that. Use it as a base FOR modular housing.


(Gordon Hoffman) #160

I’d like to see that design