And an ENTIRE THREAD devoted to “The Problem of @ellmer” that resulted (many, many times) in people leaving this forum.
Yes, @ellmer … your failure to learn from history really IS remarkable.
Problem with jackup rigs is they require permits from God and everybody. Everything within even the largest jack-ups depth range is leased, or off-limits.
… and the problem with used vessels…
Unless a company went bankrupt, odds are the vessels are 25-30 years old, which, due to forces from waves, is pretty-much the insurable limit for ocean-going vessels, due to the fatigue of materials.
As for Matias’ ‘Ramform’ things… The forces down the length of those wings/arms/whatever are going to multiply those forces, and, short of a new means of engineering, will shred the thing before that.
On the true, patented Ramform, the rear is basically a vertical truss, fully capable of withstanding those forces.
Unless Archimedes was wrong … the longer the arms of the ‘ramform breakwater’ design, the more force will be applied on the keel/“nose” by each arm.
And the ‘connected train’ scheme proposed by @ellmer won’t work, because each individual unit of the ‘train’ must be free-floating … which negates the purpose of the ramform design. That ‘train’ scheme is nothing more that a glorified version of a floating dock.
So the entire concept is bogus without an accurate calculation of the cyclic loading.
And, clearly, this calculation has NOT been done for the proposed ramform breakwater concept.
And, clearly, the ramform breakwater scheme was proposed with the intent to extend the arms.
As @ellmer wrote elsewhere …
"The thin extensions give a wide beam that increases the stabilit and move the already split waves gently along without touching the lagoon which holds the marina and the soft units (houseboats) that can not be exposed to big oceanic waves...
The tips of the arms keep growing as money flows to the venture and the lagoon fills gradually with marina walkways platforms and business protected from the waves."
Pretty sure the only people that believe in that fantasy are those that still refuse to consider costs as relevant.
Even my Ramform concept, based off the patented survey vessel design, is still expensive, as a potential DIY in ferrocement, or if I can get the geopolymer formula to work out, and go commercial. $100/sq ft is still luxury home prices, and the TSI Barge is over 6X that.
Granted, once there is one built, that design can be repeated, generally for a lot less, but still…
Many of the ‘save the world’ ideas that fly in here really need to realize that living at sea ain’t going to be a stroll in the park, hop on the scooter and get to Walmart, or whatever. Even locating just a few miles out, and you’re talking about spending all day traveling back and forth, let alone the journey to and from some proposed International Waters doughnut-hole over 200 NM out.
If roaming seasteads ever happen, they will use the same means as ships, to deal with waves.
If we’re talking about stationary platforms, then whatever it is will have to either be like the bottom structures, or take additional mooring, at tens of thousands of dollars per line and tens of thousands more, per anchor, regardless of type.
Nice thing about the bottom-structures is, they won’t move and won’t need anchors, or lines that have to be replaced, won’t need maintenance, or cleaning, and as artificial reefs, they will encourage marine life to move in, creating an oasis in the seas.
So, how can these bottom-structures be built on the cheap and placed? How about the electrolysis seacrete? Use a solar-panel, a shaped wire-mesh form, and some sort of buoy to keep it up high, during production, then use an ROV and buoyancy control to position them, once they reach some target thickness.
No need to buy hundreds of thousands of tons of concrete, at all.
Bottom (gravity-based) structures don’t have to be entirely monolithic, either. If you form a shell and fill it, then you have equilibrium of forces inside and out. It would only need to be sturdy enough to transport and then can be “robusted” by filling once emplaced.
How about we dial back the tone a bit. I’m an engineer. I’m in the Marine Technical Society and Society of Naval Architects and Marine Engineers. I have dealt with failures in mature technology embodiments. This is not such.
So… if you have the answer: what is the first mode of failure for cyclic loading based on standard seas as a basis for infinite life and then a 5x design margin for a worst case storm season all for the site in question. Coupled with this, what is the corrosion prevention scheme for stress corrosion cracking? What is the maintenance cycle? What are the field tools proposed? What is the reliability scheme?
NONE of this is trivial, especially since the other sections indicate the majority of the people involved are “passengers” as opposed to working, trained, skilled crew.
If you are going to be rude and act like you have the answers, give it up. Show me. If you don’t have the answers, then they are not addressed, they are talk about and are put on hold for a later time. These issues are life and death.
I’ve gotten all of that from the information available online.
would it be polite to post relevant links? As a seasoned engineer would you prefer to revisit all of your questions in a single post abridged for you personally, or to see the source material?
I believe what the man is asking for is an engineering spec.
That would be interesting for you to supply. What are the materials, hull thickness, gross weight and draft for your crescent shaped housing structures? What about the round domes?
In my post about optimal draft, I brought to question whether deep draft structures (concrete shells) are preferable to shallow draft (polymer/foam based shells).
It would be interesting to see your calculation as to shell thickness and weight. As you know I supplied mine in full.
There are dozens of threads in the old and current forum that address materials, concrete specifically,
The public should be aware that JW is talking about a calculation(s) he made for his novel, which is in fact poetically relevant to the plot. My visualizations are just illustrations, extrapolations, of what can be done using standard marine concrete construction as found in large existing projects, and smaller projects and experiments, in real life.
All of the above can be supported with relevant links, which I’m still in doubt whether it’s polite or not to (re) post.
We’re very far from the waves at this point so Mati out
DIY is going to tend to be significantly cheaper than anything commercially built and produced. Consider 20% of the cost of a commercially built yacht is the hull, and half of that is labor.
Now, turn it around and pay 10% of the commercial cost to build your own hull, and even 40% to equip it exactly the same, and you’ve saved 50%.
My own concept comes in at ~$100/sq ft. 15% the expected cost for the TSI Barge, and I get to put it where I want it.
Part of the plan is to incorporate the same type of passive/active flooded chambers, for additional pitch/roll/yaw control that has been retrofitted to one of the PGS Ramform vessels. The chambers are open to the water, from below, partially evacuated, and linked by airways, to shift air around, rather than try to pump high volumes of water.
Great plans here. Although I still question why the shaped hull rather than a simple rectangle. For a non-moving structure I’m not sure why the hull needs a shape at all.
Instead of the flooded chambers, why not just use gyroscopic stabilizers?
Check out this video at 1:12 - the left boat has the stabilizer
The flooded chambers are interconnected to allow air-flow, creating controlled, automatically variable ballast w/o additional power under most conditions, yet allow powered control, for stability in severe conditions, with minimal moving parts.
Gyro stabilization requires constant power and constantly moving parts that wear and need repair and replacement.
A shaped hull can weathervane with changing conditions… Part of my goal is to moor in a current, but also to weather storms, which can come from any direction. Being able to weathervane allows the hull to function properly in higher wave-states.
Would you please clarify this for me, Jeff?
I’m visualizing a floating “bottom structure” located in deep water … that somehow refracts surface wave energy between bottom and mid-level layers.
Is this correct, or did you mean something different from that?
I posted it in the Breakwater thread…
Another article on the subject…
For years scientists have been looking for ways to make invisibility cloaks a reality, by shielding objects from light and other electromagnetic waves.
But what if we could make floating objects, such as an oil platform or storage tanker, invisible to physical, water waves? Professor Mohammad-Reza Alam may have found the answer.
Alam, a fluid mechanician, and his team of researchers at the University of California, Berkeley, have come up with a technique to make these structures immune to the up-and-down motion of rough seas.
Combined breakwater and wave power generator
Broadband Cloaking in Stratified Seas
Department of Mechanical Engineering, University of California, Berkeley, California 94720, USA
(Received 13 September 2011; published 23 February 2012)
Here we show that floating objects in stratified fluids can be cloaked against broadband incident waves
by properly architecting the bottom corrugations. The presented invisibility cloaking of gravity waves is
achieved utilizing a nonlinear resonance concept that occurs between surface and internal waves mediated
by the bottom topography. Our cloak bends wave rays from the surface into the body of the fluid. Wave
rays then pass underneath the floating object and may be recovered back to the free surface at the
downstream bearing no trace of diffraction or scattering. The cloak is the proper architecture of bottom
corrugations only, and hence is surface noninvasive. The presented scheme is a nonlinear alternative to the
transformation-based cloaking, but in the context of dispersive waves.
DOI: 10.1103/PhysRevLett.108.084502 PACS numbers: 47.35.Bb, 47.11.Kb, 47.20.Ma, 47.55.Hd