I’ve seen some new jack-up rigs that can go depths of 100 meters. You could actually put this on a seamount if you wanted to.
The anchoring forces needed to counteract the surface side forces must be incredible.
I would think that you’d need to keep your platform well above the waves. The side forces on the legs would probably not be a problem since most legs are steel frames with plenty of hollow space. I’m not sure if they could rig suction anchoring on jack up legs, but that is possible too I guess.
For one thing, I’d be wanting publicity, so c’mon out and have a look around.
Uh,… Have you seen the depth charts for that area…? That’s on the Continental Shelf, not off on the Juan de Fuca Plate… MUCH shallower and Juan de Fuca Plate is far shallower than further South, past the Blanco and Mendocino Fracture Zones…
Wave Energy Converters would be rather useless above the waves…
I’m not trying to push up from the bottom, I want to be anchored and floating. A floating platform doesn’t have to have the excessive structure necessary to lift from the bottom.
By using hollow flotation legs, I get the benefits of 50 meter deep hull stability, without paying for the extra leg length and structure to reach the floor.for anything other than anchoring.
If I’m over an hour from port, who’s going to want to come out and dive? People are lazy and don’t want to beat themselves to death, motoring an hour-plus, after whatever it took to get them into the vicinity, ashore. It’s intended to be visited, unless it is merely a fish farm. Day-trip out, to dive, for a chance to see whales and sharks, from inside one of the worlds’ largest shark-cages…
Sorry JL. I was replying to Kat.
I see your point now. I think it’s doable, BUT, 75 m = 225’ x 5 spuds plus the rest, your are into tenth of $ millions investment already. You need to find a solid investor for that…
1/10 of $million = $100,000 , he can prolly grow into that size with no investor, given enough time. For a “spud”, or a very very lightweight 250ft long copy of the FLIP ship hull alone, i figure each vertical hull can be built for $10,000. That’s with zero anything on it, not even ribs, no attachments, no pumps, decks, tanks, absolutely nothing, but it would be a place in the water with air in it, so it would float. Add another $10k for making it last more than 10 minutes in the water, plus paint. So i guess you’re correct there, octavian, at $20k per leg, five legs would cost a tenth of a $million to make! throw in the bracing between, electronics, cage for, i mean house for humans, cage for fish, you prolly will hit two tenths of a $million. On the other hand, this needs to be rethought, because five such legs would float 1.5 million pounds of buoyancy, and who needs that on a B&B?
 I figured by:
250ft / 4ft = 62.5
62.5 (4x8 sheets) x 2 (to make 16ft around, or 5ft dia legs) = 125 sheets
125 sheets * $75 each (you can likely do better on this price) = $9,375
This is the cost to build (plus incidentals like welding rods). Cost to buy the leg would be much much higher due to labor and site costs.
(Personally, i’d make a 50ft fat leg with a much skinnier leg thru the wave zone. The mere 50ft of 5ft dia fat leg submerged is nearly 30 tons of floatation, and five would be 150 tons. It might cost the same, but i suspect will be much easier ride in a storm.)
It helps to remember that any vessel construction done in ferrocement typically gets cost-effective around 25 ft. (typically quoted figure from FAO). That’s actually about the size of a decent-sized multipurpose family fishing/skiing boat… I’m trying to cut that down with a DIY geopolymer, as well. Even given using more expensive Basalt rebar, should be cutting into the cost of ferrocement, as well as possibly increasing the buoyancy, due to a potentially lighter structure. Because of needing to buy in bulk, figure in cost reductions there, too.
As for the amount of buoyancy, that’s a flat buoyancy figure and doesn’t account for seawater ballasting, to achieve depth for stability, either. If I’m looking at 2/3s of the thing filled with water, and reduced buoyancy for pressurized air chambers, add reinforcement rings, chamber dividers, and plumbing, that figure will come down considerably. Conservative estimate maybe 20% remaining? If they’re jack-up capable, then they have to be uniform diameter.
Their main purpose is added stability from depth achieved, with low COG, frame the pen, and support the main hull in storms, to clear, the waves temporarily.
That’s spaghetti…It will bend and hold nothing.
Which? You gave two numbers and gave no context.
The 250 ft/ 4 ft spuds, that is.
Another thought… If the whole thing is developed as a kit-of-parts, then modeled around using almost 100% interchangeable sections and connectors, then it becomes subject to additional savings. Say that all of the platform pieces are interchangeable, all of the spar-buoy leg segments are interchangeable, possibly even interchangeable with minor differences between the legs and booms of the horizontal framework, as well as the 5 corner pieces, and the reinforcement braces, etc.
If all of the tubes are nearly the same, 2 for the aft horizontal sections, 5 with plumbing for the spar-buoy legs, then 2 with minor differences for the placement of the wave-energy converters at the bow, all plug-in at each of the 5 corners, in their respective positions. The main structure can be put together, then the legs lifted into their respective yokes and jacking mechanisms, then piloted out to position, from a sheltered construction/assembly site/bay.
Build the aft dock/platform, then the 5 corner pieces, then the tubes and legs. Work incrementally toward the completion. The main, unique component becomes the docking section.
The idea of 250ft spuds, or 4ft spuds? Keep in mind i didn’t propose spuds in the first place.
They aren’t spuds, so much as spar-buoys, using the spud yokes and mechanisms to lock them to the platform, making the whole thing more mobile, and more adjustable for the conditions.
Come to think of it, once the dock area and corner pieces are done, the 2 aft yoke/corners can be used to start building the slip-form tubes, allowing greater control of their manufacturing process…
Holeymoley that is a lot of steel just to make a fishing pond!
Could’ve used ferrocement… It’s nothing more than a mesh with wire reinforcement, around and under a miniature semi-submersible platform.