Freshwater submerged tankers to help solve the need for freshwater around the earth


Freshwater submarine supertankers to deliver large quantities of fresh water via ocean transport


Abstract

Freshwater submerged tankers, also known as “submarine supertankers,” can be visualized as very large submarines carrying on the order of 1 billion gallons of water. Unlike an ordinary submarine, the hull of the freshwater submerged tanker would not have to hold back hydrostatic pressure, which allows it to be much weaker, and therefore cheaper than a submarine hull. It is a better analogy to consider a freshwater submerged tanker to resemble either a blimp or a dirigible, in which flotation is supplied by the fresh water which is 3% less dense than seawater. This invention also drills down into very specific designs for such tankers  which may be patentable even if the general concept is not.

If the electrical energy to drive the submarine tanker comes from combustion energy, it is particularly desirable for the power generator to be a surface vessel which is connected to the freshwater submarine tanker by a power cord. If on the other hand a nuclear submarine provides the electrical energy to drive the submerged freshwater tanker through the ocean, both the tanker and the nuclear submarine supplying electric power to the tanker could remain submerged.


General description of the concept

Comparing a surface vessel versus a submarine with the same total displacement, the submarine will experience less drag than the surface vessel by virtue of the fact that the submarine generates no significant surface waves. A freshwater submerged tanker would therefore be more efficient for transporting fresh water compared to a surface tanker ship transporting the same amount of fresh water.  

The cost per unit volume of the freshwater submerged tanker would also be dramatically less than the cost per unit volume of an equivalent surface tanker. The biggest reason for this is that by moving well below the surface of the ocean it is possible to avoid ocean storms, and because of this the submarine can be made a lot weaker.  The submerged freshwater tanker hull stress comes from only two sources barring an accident: the force needed to accelerate or decelerate the huge bags of fresh water, and the drag that occurs while pulling the submarine tanker through the ocean.

The crux of this idea is that a relatively fragile freshwater tanker can be designed so that it is neutral buoyant with respect to seawater at a convenient depth, say about 200 meters down, for example. At that depth waves from surface storms would mostly dissipate and the hull of the freshwater submerged tanker would not have to be very strong to resist the buffeting of rough seas, and so the hull can be quite cheap. The whole undersea tanker could in principle be strictly comprised of inflated bags of fresh water, using the inflation pressure of the freshwater bags to provide the needed rigidity; this is the blimp design. In a blimp design, it is difficult to place the propellers so that they deliver thrust at strategic points along the hull. Below I discuss a more preferred design that more closely resembles a dirigible than a blimp, in which the thrust of any given propeller is linked to a single bag held within a particular rigid cage, which is linked to the framework of the underwater submerged tanker. If the tanker is split into a series of neutral buoyant barges, which we will call "cars," the rigid cage holding each water bag would be a part of a single car of the train.

The hull could be constructed from a hollow steel pipe-based framework designed to be neutral buoyant in seawater, for example. A pipe framework could also vary buoyancy by at times being filled or partially filled with low-density gas, while at other times being filled with water. This is but one example of a method to allow buoyancy compensation in the framework of the freshwater tanker, but it is also possible to operate using conventional ballast that is off loaded at the same time the water is delivered, in which case it is desirable for the framework to be neutral buoyant at all times; this is believed to be simpler to implement.

The freshwater submerged tanker is similar to several other prior art flexible barge designs for moving fresh water through the ocean, but it's different because it is ballasted to move well below the surface of the ocean, and because the freshwater bags are desirably held within rigid frames that are individually driven by steerable electric motors and propellers, rather than being towed. The freshwater submerged tanker could  consist of a whole train of tanker cars which share a common electric power supply, which are in mutual communication, and which are controlled as though part of one large vehicle. Each car of the train will hold one or more large water bags, composed of a polymer membrane, containing fresh water and each car of the train will supply its own thrust and its own braking.

The framework around each bag would support and protect the water bags in such a way that each bag presses against a stiff structure through which forces are transmitted from the propellers when it is being accelerated, turned, or decelerated by the propellers. In effect, each large freshwater bag would be contained in a cage comprised of stiff structural elements with a mesh size small enough to keep the water bag from pooching out between the structural elements.  

Linked to the framework structure are the drive motors and propellers. A framework structure made of rigid materials can be equipped with electric motors and propellers and a control system so that it is steerable and self-propelled through the deep ocean provided only that it receives electric power. The power could come from a nuclear submarine that is attached either at the front or the back of the freshwater submerged tanker, or from a surface ship that is in effect a mobile power plant. In either case the power would be delivered through a cable.

This is quite different than towing a large bag of fresh water as has been previously proposed, because the propulsive force is distributed along the hull, rather than having to be transmitted from the front all the way to the end of the moving train of freshwater. The method of towing a train of flexible water tanks "flexible barges" with a tow line necessarily implies a great deal of stress and fatigue both for the tow line and for the structure of the freshwater train.

I envision two types of submerged freshwater tankers  which are analogous to either a blimp or a dirigible, which are designed to carry fresh water under the sea. These vehicles are designed to be neutral buoyant in the sea, and to cruise at a depth which is suitable for long distance transportation of the cargo, water, with minimal drag and deep enough so that surface waves do not cause large structural loads. Ideally propulsion would be supplied by multiple electrically driven propellers that are attached all along the hull of the submarine water tanker, so that thrust is delivered at many different points to counter local drag  and/or to accelerate a localized portion of the total load of freshwater. This minimizes the required strength of the structure holding the submarine water tanker together compared to the alternative of simply towing a large bag of water. Given current fossil fuel technology, it would be most economical if the electrical motors are powered by a surface ship to generate electricity that is attached to the submarine water tanker by an electrical cable. Nuclear powered submarines could also supply the electric power as stated above.

Since freshwater is about 3% less dense than seawater, a large bag of freshwater needs to have ballast connected to it in order to be neutral buoyant. Each cubic meter of fresh water exerts a buoyant force equal to about 30 kg of mass while floating in seawater. Fresh water is capable of floating a rigid structure composed of materials such as metal, polymer composite, and/or concrete which are denser than seawater. This is potentially similar to the framework of a dirigible airship, so I will refer to this type of rigid-hulled submarine water tanker as a dirigible type water tanker. Since the absolute density of the sea is much higher than the density of the air, the framework structure of a dirigible type water tanker can be much heavier than that of a dirigible. The analogy goes further in that a dirigible contains bags which hold hydrogen or helium whereas the dirigible type water tanker design would contain bags full of fresh water that provide flotation.

In this design, the dirigible type water tanker framework needs to be returned to the source of fresh water in a form which is the same size as the fully loaded dirigible type water tanker, so there needs to be some way to modify the buoyancy for the return trip. This could be done by using airbags to provide flotation on the return trip, but if so, it will be difficult to maintain a consistent depth within the ocean. It appears to be simpler to design the entire framework to be neutral buoyant, and if so the return trip will produce similar drag to the fully loaded dirigible type submarine water tanker. Therefore, the energy cost for returning the dirigible type water tanker to the source of freshwater will be about the same as the cost for transporting the freshwater using the device, and the speed of transport will be about the same for the return trip as for the trip delivering the fresh water.

A blimp type submarine water tanker could potentially be designed so that the blimp is collapsed for the return trip after delivering water. This has the potential to make the entire delivery process less expensive because less energy and less time will be consumed for the return trip back to the source of water if the blimp is collapsed and carried back aboard the accompanying power plant ship. Such a water-filled blimp might be able to withstand sea waves, and so might not require ballasting so that it travels below the surface of the sea, but in this case it is essentially similar to prior art towed flexible barges, which I have not proved to be successful.

I visualize very large submerged water transport tankers which are streamlined on the outside and which contain large bladders capable of holding millions of cubic meters of fresh water, which might be collected for example from the flow of arctic rivers, such as the rivers that flow off the Greenland ice sheet. Arctic river water is very clean and could even be used for potable water without further sterilization. However in the immediate future, it is more likely that river water would be captured flowing off a continent, such as the Congo River or the Columbia River, both of which are situated near regions that are in great need of additional water resources. Critics have suggested that this is politically impossible; I think though that it is possible provided that one pays for the water.

To put the needed volumes in perspective, New York City consumes about 1 billion US gallons per day, approximately 3.8 million cubic meters of fresh water. A cylinder containing this volume would be a kilometer long by 70 meters in diameter approximately. This is the order of magnitude of the size I would consider economical for transporting large quantities of water to enable the continued viability of cities like Cape Town in South Africa,  other cities in desert regions near the ocean, or to irrigate large desert areas for agriculture, for example.

Consider as a specific example a rigid framed undersea water tanker of the type which is analogous to a dirigible, with a rigid segmented frame and containing large bags for holding fresh water comprised of polymer film, elastomers, or fiber-reinforced elastomers. For this example, consider the entire structure to be neutral buoyant without the freshwater. The design is such that when all the bags are full of fresh water the buoyancy from the fresh water equals the effective weight due to the ballast. When the fresh water is offloaded, the ballast is also offloaded so that the undersea water tanker, now empty, remains neutral buoyant for the return trip. If the ballast is something useful like sand or gravel, it is advantageous to operate in this mode. For the case of quartz sand as the ballast, for every 100 tons of fresh water, 5 tons of sand ballast would be required.

At the surface of the sea, there are always surface waves, which leads to increased drag and greatly complicates the design of tanker ships. If however a ship is designed to travel hundreds of meters below the surface of the ocean, it should be possible to avoid these surface wave effects, and therefore to construct a much less expensive ship per unit of volume contained within it. One complication with such a subsea tanker is how to generate the propulsive energy.  

I envision subsea vehicles driven by electric motors in which the electricity to drive the motors is supplied by a surface vessel that accompanies the subsea tanker vessel.  When I first conceived of such subsea freshwater tankers, I was thinking in terms of towing these vessels, similar to the technology proposed by Terry Spragg in two US patents (#5,413,065 and #5,488,921), but later I realized that driving the tanker with numerous electric motors has many advantages over towing. One advantage of driving with steerable propellers is that it will make turning easier. Another advantage is that the motive force aligns with the direction of motion, which is difficult if a submersed tanker is towed by a surface vessel. Yet another advantage of driving the subsea fresh water tanker with small propellers arrayed along the sides of the tanker is that this minimizes structural loads on the framework of the tanker. Another potential advantage for using small propellers arrayed along the surface of the subsea freshwater tanker is that a thin turbulent layer right at the surface of the tanker may tend to reduce drag, similar to the way that the dimples on a golf ball reduce aerodynamic drag or the similar dimples on the surface of a dolphin's skin reduce hydrodynamic drag.

One of the innovations introduced by Terry Spragg in his United States patents would be readily adaptable to the design discussed above for the submerged freshwater tanker train operating at depth in the ocean. Terry Spragg invented a zipper design linking the cars of his freshwater train of bags. The same basic idea can be used to minimize the hydrodynamic drag of a long train of subsea tankers as described above, except that the purpose would be to reduce hydrodynamic drag, not to serve as a permeation barrier. That means that the outer skin could be created from water permeable fabrics, and need not be watertight. Deploying such a skin around the moving train of subsea tanker cars would reduce drag.

It is noteworthy that the vast amount of freshwater flowing into the Arctic Ocean due to the thawing of Greenland has the potential to stall the Gulf Stream. Therefore taking this freshwater away from the Arctic would have desirable ecological effects, as long as all the water is not taken.

There is a critical shortage of freshwater in many regions of the Earth which hold large populations of humans. In fact, desalination plants are being built all over the world to address the critical need for fresh water, and most of these plants rely on fossil fuel for their energy, which contributes to global warming. An initial market for Arctic sourced fresh water is guaranteed if such water can displace water made by the desalination of seawater.  

Arctic sourced fresh water could also be used for agricultural irrigation, where the particularly low mineral content of glacial runoff water would be highly desirable. An obvious example of a place where such water would have high value is the northern part of Africa.

Another subtle advantage of operating freshwater tankers at a depth of hundreds of meters below the surface in the ocean would be that fouling of the hull by barnacles would be reduced or eliminated.

The following report Is based on multi-physics modeling. It shows That it is energy feasible To Transport Fresh water All the way from Greenland to Saudi Arabia. Unfortunately the figures didn't come through In my cut and paste attempt to edit to this Blog post.

SIMULATION OF SUPERTANKER MOVING UNDER WATER
The supertanker is moving horizontally and steadily under water. A whole CFD model of the surrounding water in such conditions has been performed. The aim is to compute the drag force on the supertanker, and hence the total power required to keep it moving at a certain velocity.
As known, the supertanker has the dimensions 16a x 6a x 1a (long x wide x high), as seen in image (front face is yz, as movement is in x direction), where a (= 40 m) is the side of the elemental cube.
We have used a RANS (Reynolds‐averaged Navier‐Stokes) turbulence model, particularly the algebraic y‐plus model, to solve for pressures and velocities in the water around the supertanker.

In this plot we show some streamlines of water velocity around half body. Color legend is expressed in m/s.
.

In next plot we are showing the power (in MW) needed to apply to the supertanker vs its velocity (in km/h). Both the simulated (from CFD model) and the formula (drag force, using 0.58 as drag coefficient) curves are shown. In the plot we can see that the power needed to move the supertanker at a steady velocity of 16 km/h is around 245 MW, while the power needed to move it at 8 km/h is around just 30 MW. That relation is expected, as drag force is proportional to the velocity squared, and thus power is proportional to cube velocity. Hence half velocity requires 1/8 of the power.
VELOCITY (km/h)
POWER (MW)
1
0.048898
4
3.8361
7
21.080
10
60.353
13
131.82
16
243.36

Exemplary claims

  1. A fresh water transport system comprised of two components; first is a freshwater submerged tanker to deliver large quantities of fresh water via ocean transport which is driven by many  controllable propellers powered with electricity which comes to the tanker via an electrical cable from a second power supply ship that travels along with said freshwater submerged tanker, and in which said freshwater submerged tanker travels far enough below the surface of the ocean to avoid the effect of surface waves.
  2. The fresh water transport system of claim 1 in which the power supply ship is a surface vessel containing a power plant that is connected by a cable to the freshwater submerged tanker.
  3. The fresh water transport system of claim 1 in which the power supply ship is a nuclear reactor driven submarine which is attached by a cable to the freshwater submerged tanker.
  4. The fresh water transport system of claim 1 in which said freshwater submerged tanker is comprised of numerous tank cars that are linked by being powered by the same electrical cable but wherein each individual tank car has its own propellers which are capable of independent operation.
  5. The fresh water transport system of claim 4 in which said tank cars comprise a rigid framework surrounding one or more bags of fresh water.
  6. The fresh water transport system of claim 4 in which said linked tank cars are joined together in the form of a train in which the tank cars follow each other through the ocean.
  7. The fresh water transport system of claim 6 in which the said train of tank cars is covered by a fabric shell which is water permeable but which provides a smooth surface to minimize hydrodynamic drag.
This was filed as a US provisional patent application Linked below is a document that will be sent to Michael Burry.

https://docs.google.com/document/d/1KWtI7Xft9Sw5c5M8XNYwzMpv4DekMHWgLxqjkmd4T7I/edit?usp=sharing

Comments

  1. I am pursuing an unusual strategy on this invention.I am pursuing and unusual strategy on this invention. I filed a provisional US patent yesterday. Today I am reviewing my idea to the world in such a way that it will no longer be possible to patent it that is for anyone but myself... Because I already filed my provisional patent.

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