INSTALLING THE GULF STREAM TURBINES
Although the invention has been described by engineers as being well conceived and timely, legitimate concerns have been expressed about how these machines would be installed and later recovered for servicing or repair. Though these tasks may seem daunting, with planning, they can actually be accomplished without great difficulty. We will begin with the following drawing that shows an example of one way that the Gulf Stream Turbine can be anchored and attached to the electrical system.
With the proper equipment, it would be possible for hundreds of these machines to be installed without a single person getting in the water. It is extremely important that the installation strategy facilitates the later recovery and replacement of the individual units. The following shows the groupings of the tasks separated into eight major parts:
1) Placing the anchor and anchor lines;
2) Laying the transmission cable to carry the electricity to shore;
3) Joining the electricity collecting cable segments to the electricity collecting cable assemblies;
4) Joining of the electricity extension cables and the anchor line extensions to the electricity collecting assemblies and the anchor line;
5) Connecting of the other ends
of the electricity extension cables and the anchor line extension to the
6) Lowering of the Gulf Stream Turbines into the water’s surface;
7) Submerging the string of many Gulf Stream Turbines;
8) Energizing the generators’ field current to produce electricity.
The maximum tension on the anchor lines will be determined by the machine’s peak capacity and the systems used to protect the generators from an excessively fast current. These systems could include variable-pitch rotors, rotor blades that limit the torque by stalling, magnetic or fluid torque-limiting clutches, the disconnecting of the generators’ stators from the grid, and adjusting of the lifting forces to allow the Gulf Stream Turbines to descend into slower water.
The anchor lines can be made of carbon-fiber filaments twisted into cables, or they can be bundles of carbon-fiber rods. The cables would be more flexible, which would allow them to be wound onto smaller spools. The bundled rods, though stiffer, should provide more strength per pound. It is the bundled rods that are being used for anchoring semi-submersible offshore drilling platforms in deep water. Unlike the anchor lines for ships, once the Gulf Stream Turbines have been installed, there will be no need for flexibility.
The fastest ocean currents are almost always located near the surface. The Gulf Stream Turbines will normally operate at depths of between 90 and 300 feet where the total water depths will range between 900 and 1,500 feet, putting them between 800 feet and 1,400 feet above the ocean floor and safely below any surface ship traffic. Assuming there would be no droop in the anchor line, the anchor line’s length would equal the cosecant (reciprocal of the sine) of the anchor line’s angle, multiplied by the height of the anchor line’s hitch point above the anchor. If the anchor line’s angle were 10 degrees, for every 100 feet that the anchor line’s hitch point is higher than its anchor, 576 feet of anchor line will be required. For an angle of 30 degree, 200 feet would be required. As the angle increases, the tension on the anchor line on the anchor line would also increase because of the increasing hydrodynamic lift required to balance the increasing downward vector forces – but that would be only be if the unit were to remain at a constant depth regardless of current velocity. If those lifting forces increase more slowly than the downward vector forces, the Gulf Stream Turbines would descend from the faster currents near the surface into the slower currents at greater depths. This can be accomplished by either reducing the distance between the Gulf Stream Turbine’s hitch point and its center of drag, or by increasing the anchor line’s angle where it attaches to the Gulf Stream Turbine. Doing the former would reduce the increases in the lifting forces; doing the latter would increase the increases in the downward vector forces.
To prevent the long anchor line from sagging, their specific gravity should be near that of the salt water they will displace. Carbon-fiber composites weigh between 106 and 113 pounds per cubic foot, giving them a specific gravity of between 1.7 and 1.81. Carbon-fiber anchor lines, having a diameter of 2 inches, would weigh approximately 2.314 pounds per running foot when out of the water, but only .918 of a pound when submerged. Depending on how far the Gulf Stream Turbines will operate above the sea floor and the anchor lines’ angles, the lengths of the anchor lines could be anywhere from about 1,500 to 4,500 feet, putting the total submerged weights of the lines between 3,471 and 10,413 pounds. Therefore, some additional floatation would be required to give the anchor lines neutral buoyancy. If the 2-inch carbon-fiber lines were used, only 183.6 pounds of additional lift would be needed for every 200 feet of anchor line. Because salt water weighs 64 pounds per cubic foot, the displacement of just 2.87 cubic feet of water would provide that amount of lift. If the lines had a diameter 3 inches, the weight per foot would be increased by a factor of 2.25 so that the cubic feet of water displaced would be 6.46 cubic feet, equivalent to a sphere with a 4-foot diameter being attached at intervals of 200 feet. These floats can be placed at almost any distance apart as long as their volumes are proportional to the lengths of negatively buoyant lines they are supporting. Prior to winding the cables onto the drums, the cables should be marked at those intervals where the floats will be attached during the installation process.
If the much stiffer bundled carbon-fiber rods are to be used, the best plan might be to have their much larger reels mounted with their diameters vertical and length-wise. The lower of the preceding drawings show a vessel designed to perform the same work as the vessel in the upper drawings – the only difference being that this one can handle the same type of stiff bundled carbon-fiber rods that are used to secure the semi-submersible oil drilling platforms. The catamaran’s two hulls extend well aft to get the center of buoyancy under the load. (No effort was made to draw these watercraft and systems to scale – the drawings simply illustrate concepts.)
Regardless of the type of craft used to place the anchors, the unwinding of the lines from the spools must be controllable because it will be necessary to stop them at intervals to allow workers to add the required floats to neutralize the lines’ buoyancy. They must also be stopped when each of the lines is out so that the workers can attach larger floats to the ends, prior to dropping them into the water for later retrieval.
Although it would be possible to apply the breaking system through a spool’s axis, it would probably be better to apply it through the spool’s rims because of the leverage provided by the spool’s radius. Having gears located below deck that would have teeth projecting slightly above deck and under the spool would not only make it possible to control the speed of the spool’s unwinding, but they could also be used to rewind an anchor line back onto a spool, if there should ever be such a need. After the anchor has been dropped and is resting on the ocean floor, the vessel would allow the current to carry it backward, periodically stopping that backward drift when floats were to be attached. After almost all of the line is in the water, the top end of the anchor line is attached to a large float, which would than be dropped into the water.
The following drawing shows how the alternate lengths of the anchor line extensions staggers the Gulf Stream Turbines to provide greater clearances.
the anchors and the float-supported end of the anchor-line are dropped into the
water, the lengths of some of the anchor lines might need to be trimmed so that
all the ends for a string of Gulf Stream Turbines are in a reasonably straight
line. The lateral distances between each
of the anchor lines would then be measured and, based on those measurements,
the electricity collecting cable segments are cut to be about 10 to 15 percent
longer than the measured distances. The
appropriate fittings are then attached to the ends of the segments so that they
are watertight. When the fabrication of
each of the segments is completed, they are attached to the undersides of the anchor lines, near
their ends. The vessel’s deck should be
sufficiently large to carry many of the pre-assembled collecting cable
segments, which would normally have lengths of between 160 and 200 feet.
With the floating ends of the anchor lines supported by the floats, the catamaran moves from one float to the next to allow workers to attach the collecting cable segments to the bottom of the anchor lines, and the female end of the cable segment to the male end of the next segment. One worker would lift the floats to which the anchor line is attached and the vessel would move forward so that the float and the attached anchor cable is suspended over the front of the boat’s deck. Another worker then lifts the end of that segment so that it can be attached to the underside of the anchor line. A second crane would then release that segment and pick up the opposite end of the next segment. After the two segments are joined, the vessel’s power is reduced to allow the current to ease it backwards – while the first crane lowers the float and the attached lines back into the water. The catamaran then moves on to the next float, feeding out the next cable segment, to repeat to process.
Although the electricity collecting cable segments will be heavy, little or no additional floatation should be needed to support them because they should have almost the same density as the salt water they will displace. Acid-cured rubber weighs about 65.52 pounds per cubic feet – almost the same as the 64 pounds per cubic foot of the salt water. If an electrical cable of that density had a diameter of 4 inches and a length of 168 feet, it would weigh 961 pounds on land but only 22.25 pounds when submerged. If the cables had a diameter of 6 inches, their weights would be 2,162 pounds on land and only 50 pounds submerged. Although the conducting wires within the cables will have greater densities than the rubber, they should not add more than about a hundred pounds to the cable segments’ submerged weights.
Although the attaching of the electricity extension cables and the anchor line extension cables can be done as separate operations, it would be easier if those jobs were done at the same time that the Gulf Stream Turbines were being attached to the ends of those same cables and lines. The following drawing shows a catamaran designed for this purpose. It carries three Gulf Stream Turbines, suspended from an overhead track. The electricity extension cable and the anchor line extension are carried draped along the starboard side. Each colored line in the drawing represents a pair of electricity extension cable and anchor line extension. Each of these pairs is bundled together, side-by-side, except for about 6 feet at the end that is to be attached to the Gulf Stream Turbine. While being carried on this vessel, the centers of the longer pairs of lines and cable would be suspended high on the starboard side of the frame that supports the overhead track. There are also holders projecting from the starboard side of the hull to support the shorter pairs. Having each of the pairs of cables and lines bound together will make the installations much easier and the later replacement of the individual units possible.
The vessel will be under power while working to maintain its position in the current. Like the other two drawings of the watercraft, this vessel is equipped with two forward and two rear jet drives that can be rotated 360 degrees. The pictures show them combined with steering fins to permit better lateral control when moving from inertia with the power off. All of the vessels used for the installation of the Gulf Stream Turbines can be equipped with radio-control systems to permit them to be controlled from anywhere on board. These systems can be almost as simple as those used to control R/C model airplanes.
Although the waters of
the Florida Straits can become rough during tropical storms, because the
islands of the
Facing the current, the vessel would move up to a float to which the top end of the anchor line has previously been attached. The forward crane lifts the float and its attached cables to allow the front of the catamaran’s deck to ease under them – while the telescoping boom of the crane that is supporting the float is being retracted to maintain the float’s position over the water. Then, while the electricity collecting cable assembly and the electrical cable extension are suspended over the deck, the two halves of the waterproof junction box can be joined together. After they have been joined and the anchor line extension has been connected to the anchor line, the opposite ends of the cables and lines would be attached to the Gulf Stream Turbine that is suspended at the vessel’s stern. While this is being accomplished, the boat will be allowed to drift slowly backwards to remove most of the slack from the lines and cables.
The top view of the catamaran shows two retractable platforms at the vessel’s stern that can be rolled out under the Gulf Stream Turbine’s attachment points. After connections are made, the float that has been supporting the anchor line would be removed. The newly connected cables and line extensions are then dropped into the water along the vessel’s starboard side. The Gulf Stream Turbine can then be lowered into the water. Although the moving water will begin to spin the turbine’s rotors, because there will be no magnetic field in the stators to induce electricity in the spinning armatures, the freely spinning turbines would produce little drag.
Because the distances between the installed machines could be less than their operating depths, all of the Gulf Stream Turbines in a string will normally be submerged either simultaneously or in very rapid succession. If no bottom weights are to be used, the submersion process can be accomplished by simply throwing the switches to energize the generators’ stators, starting at the end nearest to shore. As the Gulf Stream Turbines’ generators start producing power, their increased drag will increase the downward vector forces that will pull them down to their operating depths.
If bottom weights are to be used, special rigid floats can be used that will allow the bottom weights and the machines to all descend simultaneously and at uniform rates. Either clock-timers or a radio signal (similar to those that are used to open garage doors) can be used to start the process. Regardless of the system used, the submersions would begin by simultaneously opening all of the floats’ water-intake and air-escape valves to allow all the floats to fill with water at the same rate. Concurrently to the opening of these valves, other timers are started that will control the rest of the process. As all the floats simultaneously lose their buoyancy, the bottom weights will pull them down until those weights are all resting on the ocean bottom and all of the Gulf Stream Turbines are floating at the desired depths. Because the flooded floats will be both deeper and upstream of the Gulf Stream Turbines, they cannot be recovered by simply increasing their buoyancy to allow them to float to the surface because the current would carry them crashing into the turbines’ spinning rotors. This problem can be easily avoided by having the floats pass under the turbines. After sufficient time has passed for all of the floats to be completely flooded, the timer that was started at the beginning of the submersion process closes all of the water and air-release valves. The floats will now have some negative buoyancy and they will be lying on their sides with their tops pointing downstream.
Though the floats have been flooded simultaneously for their descents, they will be released sequentially for their ascents and retrieval. The timer on the float at one end of the submerged string of Gulf Stream Turbines will disconnect the float from its connection to the Gulf Stream Turbine’s anchor line. Because the float will be slightly heavier than the water, it will slowly sink – while the current is carrying it beneath the turbine’s rotors and beyond. As the current is carrying the float along, the float’s heavier bottom end will cause it to become vertical. After enough time has elapsed for the float to be safely past the Gulf Stream Turbine, the timer opens a valve on an attached tank of compressed air. The compressed air rushes into the float’s water-filled tank. There is a pipe that extends downward from the bottom of the float’s tank that is equipped with a check valve. This check valve will open only if the float’s inside pressure exceeds the ambient outside pressure. As the compressed air fills the float’s rigid tank, the rapidly increasing inside pressure will drive the water out through this pipe. The escaping water’s will jet the float toward the surface, while, at the same time, the float will be becoming increasingly buoyant. The float will pop to the surface, with its tank empty of water. Because the float’s bottom is heavier than its top end, it will continue to float vertically to allow it be easily hooked and pulled from the water. The time period separating the ascents of the individual floats will be the amount of time required to retrieve them.