The Seasteading Institute

Dunno. I believe these underwater vents were bombarded to ecological niche sometime ago. Mining them would probably be frowned upon.

That, and seasteading as envisioned by TSI necessarily includes an element of mobility: structures permanently attached to the ocean floor are a different in a way, as they do not provide dynamic geography.

Eelco – vents seem to be temporal events that may last less then a decade. So a seastead to exploit them has to move. The general idea is to leave the seastead floating in the watercolumn and harvest the 300 degree hot metal rich liquid mineral water somewhat above the ground without disturbing the vents bio-diversity. As the water is extremly hot it would go up hundreds of meters in a tubing by itself while cooling to “workable” temperature.

Jack – The seastead would float in cold water and at the same time have a extremly hot water source available (energy and aircon) so i assume general circumstances of living would be much more pleaseant than in a arctic mining operation, a tropical jungle mining location, desert location, etc…

Consider that this kind of seastead would have a “good reason” to establish on the mid atlantic ridge outside EEZ – that goes far beyond “political reasons” – it would be big business.

Wil

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Paper Number 3011-MS
Title OCEAN IMPLOSION TEST OF CONCRETE (SEACON) CYLINDRICAL STRUCTURE
Authors Roy S. Highberg and Harvey H. Haynes, Civil Engineering Laboratory
Source

Offshore Technology Conference, 2-5 May , Houston, Texas
Copyright 1977. Offshore Technology Conference
Language English
Preview ABSTRACT

An ocean implosion test was conducted on a pressure-resistant concrete cylindrical structure to obtain the depth at implosion. The structure was a reinforced concrete cylinder with hemispherical end caps, twenty feet (6.1 m) in overall length, ten feet (3.05 m) in outside diameter, and 9.5 inches (241 mm) in wall thickness. The structure was near-neutrally buoyant having a positive buoyancy of 12,000 pounds (5.4 Mg) for a hull displacement of 85,000 pounds (38.5 Mg). The implosion depth of the cylinder was 4700 feet (1430 m). A predicted implosion depth, using an empirical design equation based upon past test results, was 16 percent less than the actual implosion depth.

INTRODUCTION

A pressure-resistant, reinforced concrete hull was constructed in 1971 as part of a Seafloor Construction Experiment, SEACON I. The structure was placed on the seafloor at a depth of 600 feet (180 m) for 10 months. Figure 1 shows the SEACON I hull prior to its ocean emplacement. Since its retrieval in 1972, it has been located in the open air about 150 ft. (50 m) from the ocean. In the summer of 1976, the structure was returned to the ocean for an ultimate load test, that is, the structure was lowered into the ocean until implosion.

SPECIMEN DESCRIPTION

The cylindrical structure was assembled from three precast, reinforced concrete sections. The straight cylinder section, 10.1 feet (3080 mm) in outside diameter by 10 feet (3050 mm) in length by 9.5 inches (241 mm) in wall thickness, was fabricated by United Concrete Pipe Corporation. The concrete hemisphere end-closures, 10.1 feet (3080 mm) in outside diameter by 9.5 inches (241 mm) in wall thickness, were fabricated in-house. Tolerances on the sections conformed to concrete pipe standards of not to exceed to ±0.75 inch (19 mm) for the inside diameter or minus 0.5 inch (13 mm) for the wall thickness.

Steel reinforcement in the amount of 0.70% by area was used in both the axial and hoop direction. Reinforcing bars of 0.6 inch (15 mm) diameter were employed throughout the structure. A double circular reinforcement cage was fabricated for each precast section; the concrete cover on the outside and inside reinforcing cage was 1 inch (25 mm). For the cylinder section, hoop rebars had a spacing of 27.25 inches (692 nm) and 31.25 inches (794 mm) for the inside and outside cages respectively.

The hemispherical end-closures were bonded to the cylinder section with an epoxy adhesive, no other attachment besides the epoxy bond was employed (Figure 2). The gap between the mating surfaces of the hemisphere and the cylinder was less than 0.13 inch (3 mm) for 75% of the contact area. Prior to epoxy bonding, the concrete surfaces were prepared by sandblasting and washing with acetone.

Source: http://www.onepetro.org/mslib/servlet/onepetropreview?id=OTC-3011-MS&soc=OTC

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Offshore Technology Conference, 2-5 May 1988, Houston, Texas
Copyright 1988. Offshore Technology Conference
Language English
Preview ABSTRACT

The U. S. Naval Civil Engineering Laboratory has developed formulas to predict the collapse of hollow concrete spheres or cylinders and has shown that they can remain watertight under the pressure of chemically active deep ocean seawater. This paper tabulates wall thickness, volume of concrete, weight of displaced water, and gives a concrete cost factor for several interior dimensions of one-atmosphere habitats or valve chambers for oil and gas wells, and describes a low-cost method for building submersible concrete structures by shotcrete laminating in floating formwork.

INTRODUCTION

The need for a “shirtsleeve” environment for workmen servicing subsea oil and gas wells has long been recognized, and by 1969 the Lockheed Missiles and Space Company had constructed a seafloor pressure chamber called a “wellhead cellar” of steel designed to be lowered from the surface and connected to each well in the undersea field (1). More recently, a study was made on the feasibility of a one-atmosphere subsea collection, test, kill, and transport system for controlling and delivering gas from multiple wells in the Troll field off Norway in 1,115 ft. of water (2). Access to the subsea chamber is via a lift inside a slender steel nonarticulated tube “monopile” which provides a continuous atmospheric connection with the surface and supports a helideck.
In the past 20 years more than 60 undersea habitats have been deployed for scientific research, or for military, commercial, and recreational use. More are needed, and concrete is the cheapest and most durable material for marine use, but innovative building methods are required to make concrete economically feasible as a substitute for welded steel construction. This paper presents new methods and concepts for using concrete offshore.

BACKGROUND

In order to determine the long-term durability of concrete in the deep ocean, the U. S. Naval Civil Engineering Laboratory immersed 18 concrete spheres in the Pacific Ocean at depths ranging from 1800 to 5000 ft. Each sphere was 66 inches in diameter with 4-inch thick walls and was designed for a working depth of about 3000 feet at 1300 psi.
The design strength of the concrete was 8000 psi but after 5 years, tests showed a 15 percent increase. This remained the same after 10 years. No visible deterioration of the concrete was observed in any of the spheres and leakage varied from 0 to only 14 gallons after 10 years.
Spheres immersed beyond the designed depth collapsed and a formula was developed to predict the wall thickness needed for concrete spheres and cylinders of various outside diameters to survive at various depths (3). The authors contemplated that in the future, methods may be developed to build massive structures on the seafloor at which time it would be desirable to have designs for negative buoyancy and deeper depths.

Number of Pages 4

Looks like there are already mining efforts in progress…seems to be basicly a soup of concentrated mining grade mineral comming out on a well defined spot.

en.wikipedia.org/wiki/Hydrothermal_vent

Bob Ballard i giving an interesting talk about this theme. Speaking of “mining grade gold” and other resources.

http://www.ted.com/talks/view/id/264

On of the big arguments against seasteading has always been – there is nothing to base a solid business on – “out there”. Looks that we just don`t know yet what is out there on mid ocean and below.

The reason why those vents would play a keyrole in seasteading is because they are the first known “businessfocus” in mid ocean worth to go after. It might be a submerged operation or a remote controlled surface operation at the end – but one thing is clear already this is a “south african gold mine” out of EEZ well worth developing for the BIG money.

The technology might be a blend of “deep sea salvage technology” with deep sea/oil gas industry and mining industry.

Wil

concretesubmarine.com

European Submarine Structures AB

Why would you LOVE robots? All they do is take jobs from humans. Because of that, millions of children are straving and dying as we speak.

Why would you LOVE robots?

I’ve incarnated as a robot, for over 150 million years.

Though that was over a billion years ago.

There’s still some nostalgia,

especially considering the local tranhumanism.

We use cellphones and computers as commonplace extensions of our bodies.

All they do is take jobs from humans.

You can incarnate as a machine,

for instance when it has enough capacity,

to make it a spiritually growing experience.

Because of that, millions of children are straving and dying as we speak.

Jobs are slave labour.

Children are dieing because their parents aren’t growing food

in permaculture or forest gardening manner,

which is the best for drought-prone areas.

A ROV is not really a robot

It’s a remote controlled robot.

- but ROV technology is fairly well developed so that you can do almost anything in the deep sea that is necessary

to bring metal crusts up or suck up metal rich mud, recover diamonds, etc.etc. all this already exists.

that’s great to hear!

The problem like anywhere is cost. To deploy a ROV on the mid ocean ridge you need a expedition ship that costs 80.000 dollar a day.

If we seastead on the ocean, then it will be free, or seasonal if we are on a migrating current.

By having autonomous or semi-autonomous robots,

we can significiantly reduce costs.

Since we can simply dump them out,

they can go down, load up on what their are to retrieve.

And then float back up to the surface,

to be picked up by us.

To have some kind of overview of what is happening with the boats,

we can use sonic repeater robots, which might be spaced at half a kilometer intervals.

It could help to have directional sonic emissions, to seperate those going up and those going down.

Anyhow, via these repeaters, robots could communicate with the surface ship,

as long as they are within range of a repeater.

compressed oxyhydrogen can be used as a renewable fuel.

Things change signifficantly if you would count with a nkossa barge sized permanent platform on the mid ocean ridge that allows you to lower the ROV trough a quiet “moonpool” in the center of the barge. You have a “uptime” of 90% and numbers turn black quickly.

we could certainly have such “moonpools” or areas of relatively still water,

as components of our artificial islands.

Even better if you could lower the gear from a submarine that is not affected by weather, or work from a deep sea station like vent base alpha.

that might require pressurised rooms, which have additional costs and health risks.

Some of the richest mining spots in the world came into existance due to ancient hydrothermal processes, thr mid ocean ridges are the “mother of all hydrothermal processes” – we discovered that recently (look Bob Ballard) – is this a good reason to float out something big to a mid ocean location and do some serious business?

Sure.

Well I’m more interested in it,

as in order to be self-replicating,

we require a source of metal for ferro-cement structures.

Getting minerals from the ocean floor is a viable route.

calm aware desire choice love express intuit move

The costs will vary depending on whether you buy or build your machines, a wild guess would be that you would need to sell thousands of tons of recovered materials to make the whole project economically viable, ROV’s are not suited to recovering so much material, it would be better to have a large “harvester” permanently on the seabed to do the mining, then putting the material in boxes and using airbags to lift them to the surface.

The harvester would have an umbilical cord to carry power and control from the surface.