ARRANGEMENT FOR A SELF-PROPELLED WATERCRAFT SUPPORTED BY ARTICULATED CLUSTERS OF SPAR BUOYS FOR THE PURPOSE OF PROVIDING A MOBILE, WAVE MOTION-ISOLATED, FLOATING PLATFORM
20170158290 ยท 2017-06-08
Inventors
Cpc classification
B63B39/02
PERFORMING OPERATIONS; TRANSPORTING
B63B1/14
PERFORMING OPERATIONS; TRANSPORTING
B63B2001/044
PERFORMING OPERATIONS; TRANSPORTING
B63B1/107
PERFORMING OPERATIONS; TRANSPORTING
B63H25/02
PERFORMING OPERATIONS; TRANSPORTING
B63B39/005
PERFORMING OPERATIONS; TRANSPORTING
B63B22/18
PERFORMING OPERATIONS; TRANSPORTING
B63H11/02
PERFORMING OPERATIONS; TRANSPORTING
B63B2035/442
PERFORMING OPERATIONS; TRANSPORTING
B63B1/048
PERFORMING OPERATIONS; TRANSPORTING
International classification
B63H11/02
PERFORMING OPERATIONS; TRANSPORTING
Abstract
A mobile, wave motion-isolated, waterborne device having a platform with a plurality of support members extending beneath the platform configured to receive an articulated joint. The device further includes a plurality of corresponding clusters of spar buoys, wherein each spar buoy has an articulated joint at a first end of the spar buoy and a ballast operably configured at the second end. The articulated joint of each spar buoy within the cluster corresponds to a swivel footing configured to receive an articulated joint. The swivel footing itself includes an articulating joint. Each articulated joint of the swivel footing corresponds to one of the support members of the platform. The cluster of spar buoys can optionally move between a vertical orientation and a horizontal orientation. An optional movable ballast may be used in place of a stationary ballast. The invention also includes optional thrust/propulsion, steering, and damping features.
Claims
1. A mobile, wave motion-isolated, waterborne device comprising: a platform having an upper and a lower surface with a plurality of support members projecting beneath the lower surface, said support members configured to receive an articulating joint; a plurality of swivel footings, one swivel footing corresponding to one of the support members, each swivel footing having a central pivot with an articulating joint that is configured to be received within the support member, each swivel footing also configured to receive a plurality of articulating joints radially spaced apart from the central pivot; and one or more ballasted floatation devices wherein each ballasted floatation device corresponds to a single swivel footing.
2. The device according to claim 1 wherein the swivel footing includes a plurality of arms having a first end that is operably connected to the central pivot and a second end that is configured to receive an articulating joint.
3. The device according to claim 1 wherein the ballasted floatation device further comprises a plurality of spar buoys wherein each spar buoy includes a tubular shell, a first end having an articulated joint that is configured to be received within one of the corresponding swivel footings, and wherein each spar buoy also includes a second end that is operably connected to a ballast.
4. The device according to claim 3 further comprising a propulsion module configured to attach around a spar buoy without penetrating the tubular shell, said module having a housing, an impeller positioned within the housing, and one or more nozzles.
5. The device according to claim 4 wherein each nozzle is positioned partially circumferentially about the tubular shell of the spar buoy and wherein each nozzle is configured to articulate through an angle of 90 degrees.
6. The device according to claim 1 further comprising a steering mechanism.
7. The device according to claim 3 further comprising one or more levels of articulation between the clusters of spar buoys and the support members of the platform.
8. The device according to claim 3 further comprising a damping assembly configured to be operably connected to a second end of at least one spar buoy per cluster.
9. A mobile, wave motion-isolated, waterborne device comprising: a platform having an upper and a lower surface with a plurality of support members projecting beneath and operatively connected to the lower surface of the platform; a plurality of swivel footings wherein each swivel footing includes a central hub and radially spaced out access points, and wherein one swivel footing corresponds to one of the support members; a plurality of ballasted floatation devices, wherein each ballasted floatation device corresponds to a single swivel footing, and; articulating joint means between the central hub of each swivel footing and its corresponding support member.
10. The device according to claim 9 wherein the articulating joint means comprises a ball and socket joint, a universal joint, a gimbal joint, or a spherical bearing joint.
11. The device according to claim 9 wherein the ballasted floatation device includes pivoting movement means.
12. The device according to claim 11 wherein the swivel footing includes a plurality of arms having a first end that is operably connected to a central pivot and a second end that is configured to receive an articulating joint.
13. The device according to claim 9 further comprising propulsion means.
14. The device according to claim 9 further comprising steering means.
15. The device according to claim 9 wherein each ballasted floatation device comprises one or more spar buoys having a tubular shell, a first end, and a second end that is operably connected to a ballast.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] Like reference numerals are used to designate like parts through the several views of the drawings. The accompanying figures, which are incorporated herein and constitute a part of this specification, illustrate various exemplary embodiments.
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DETAILED DESCRIPTION OF THE INVENTION
[0034] The present invention relates to mobile wave isolated waterborne platform devices of any size that may be useful for the conduct of operations requiring a low motion environment, (minimal pitch and roll) while at sea, or upon any body of water large enough to develop significant waves. While any vessel or marine platform may be anchored, including this invention, the self-propelled embodiment of this invention provides greater flexibility of operations for the purpose of navigation or station keeping while retaining the option of using anchors.
[0035] Referring to
[0036] Each spar buoy 4 is an elongated tubular shell 5 having a first end 6, which may also be referred to as a top in a vertical position, and a second end 7, which may also be referred to as the base. The top of each spar buoy 4 is closed with a cap 8 having a pivot 9, together which may be referred to herein as a pivot cap 10. The base of each spar buoy 4 is operably connected to a ballast 11. Tubular shell 5 may be made of any suitable rigid material capable of resisting water intrusion. Spar buoy 4 may be small or large, depending on the application and the size of the associated platform. Large spar buoys could be constructed economically from marine grade, reinforced concrete.
[0037] Ballast 11 may be made of a material of high density. Ballast 11 is operably connected to base 7 externally or internally (not illustrated) of its associated spar buoy 4.
[0038] Spar buoys, as illustrated, are of circular cross section but they may be of any closed shape projected along an axis. Ballast 11 has been illustrated as a spherical mass but may be sculpted to a hydrodynamic form which may assist in reducing drag while the vessel is underway in either the upright or retracted configuration. The mechanism for relocating the ballast has been illustrated as a simple swinging lever, however, a track mounted system, or a cable drawn system, or other means of creating the required displacement may be employed.
[0039] Swivel footings 3, 3, 3, and 3, as illustrated in
[0040] Footings 3 have been illustrated as star-like shapes with arms radiating from a central hub, however, they could easily be circular discs, rectangular blocks, or any other shape having multiple pivot attach points for support from three or more buoys and a single main pivot point for support of a higher platform. When equipped with a propulsion module (or thruster) 29 (see
[0041] Ball and socket articulating joint attachment means are illustrated in
[0042] Referring particularly to
[0043] A spar buoy's natural oscillation period may be calculated using equation 1.
T=2{square root over (M/AG)}(1)
Where T is the time period of one oscillation, M is the mass of the buoy/load combination, A is the cross sectional area of the buoy, is the density of the fluid medium (sea water) and G is the gravitational attraction of the Earth at sea level.
[0044] The study of vibration response is a well documented and complex science. In simple terms, if the natural oscillation period of a system is more than 1.7 times the period of the forcing function (sea waves) the system will not resonate and will respond marginally to the forcing function. So for waves with five seconds between crests such as found in the Gulf of Mexico, a buoy should have a natural period of 8.5 seconds or higher. For wave sets with 10 seconds between crests, the buoy should have a natural period of 17 seconds or higher. The period T in equation 1 may be increased by either increasing the mass M or decreasing the area A or may be decreased by doing the opposite.
[0045] Response to waves may also be decreased by spreading the buoys and buoy clusters so that they will each ride a different part of the wave. The displacement of the center pivot of a footing will be the average of the individual buoy displacements, thus if some buoys, or clusters are riding up a wave while other are riding down, the average will tend toward being neutral.
[0046] The velocity of sea waves is given by equation 2, where L is the wave length and T is the period.
v=1.25{square root over (L)}or v=L/T (2)
A little algebra yields equation 3.
L=(1.25T).sup.2 (3)
[0047] Knowing the wave length allows the buoys to be positioned so that they will be out of phase with the other buoys. The angle of phase may be computed by equation 4 where L is the wave length and D is the distance between buoys.
[0048] Values of D/L of 0.333 or higher will ensure that the inputs from individual buoy response do not interfere constructively.
[0049] Additional layers articulation may be added by the insertion of footings between the platform and the first level footings for increased wave isolation. The platform in
[0050] Referring now to
[0051] A second embodiment of the invention is illustrated in
[0052] Referring now to
[0053] Referring now to
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[0055] Referring now to
[0056] The upper decks or platforms shown in the Figures are of simple geometric shapes but by no means should this imply a restriction of the possible shapes and functions of the upper platform. The platform may have at least three pivot attachments to the footings and be of sufficient size and strength to survive the marine environment. After this has been achieved any shape imaginable is possible. Very tall structures may lead to decreased stability and increased sensitivity to wind.
[0057] In order to provide a sense of scale the following table lists the properties of vessels based on the diameter of the buoys. All features of the vessel are increased by the same amount. (A buoy with twice the diameter will generally be twice as long). All vessels in the table have the same spar buoy length to diameter ratio, which may be changed to adjust the natural oscillation period.
TABLE-US-00001 Useful Load, Metric Draft Fully Tons Loaded Buoy (Structure and Deployed/ Diameter Payload) Retracted Natural Period 1 meter 22 to 30 8.5 to 11/ 5.0 to 5.2 seconds 1.8 meters 2 meters 174 to 242 17 to 22/ 7.3 to 7.4 seconds 3.6 meters 5 meters 2,700 to 3,774 43 to 55/ 11.5 to 11.7 seconds 8.9 meters 10 meters 21,700 to 30,118 85 to 110/ 16.4 to 16.6 seconds 18 meters 20 meters 174,000 to 2,41510 170 to 220/ 23 to 23.5 seconds 36 meters
[0058] Vessels of all sizes and load capacity may be created to any speciation. A vessel as in
[0059] This invention may be expressed in three basic modes. The first mode is that of a passive wave isolation platform device 100 that is towed into position and anchored. This mode is the simplest form and is shown in
[0060] The second mode, such as illustrated in
[0061] The third mode, such as illustrated in
[0062] If the vessel is underway at a low speed when initiating transition, the drag of the motion through the water will help keep the buoys aligned in the same direction as they swing from vertical to horizontal or vice versa. This is in addition to the natural tendency of the buoys to tilt in the direction of the displacement of the ballast from the buoy's central axis. By keeping the buoys within a cluster oriented so that the ballasts all swing in the same direction and maintaining a small amount of velocity through the water, a gentle transition may be managed.
[0063] A vessel of this mode will have access to a greater number of ports when returning from sea or seeking safe harbor. However, with the buoys in horizontal alignment, much of the wave isolation capability will be lost. Such a vessel should only be used in the horizontal buoy alignment configuration while navigating through shallows in fair conditions.
[0064] Referring to
[0065] When ambient wave periods are within 1.7 times the natural bob period of the supporting spar buoys, the footings and platform will begin to respond and oscillate due to the motion of waves. The nearer the wave period is to being equal to the bob period, the more pronounced the response will be. This is when the damping fin assembly is useful to providing a comfortable, stable environment on the platform.
[0066] The depth of the bottom end of the buoys will typically, and by design, lie below the depth at which water is disturbed by the motion of surface waves. This allows a damping fin placed at the low end of the spar buoy to be most effective. Each fin's broad surface lies perpendicular to its corresponding spar buoy's vertical axis. With enough surface area, the damping fin assembly will resist oscillation along the vertical axis induced by waves of similar period to the nature bob period of the spar buoy.
[0067] On a transitioning spar buoy equipped with a damping fin assembly, hinge 45 (
[0068] Advantages of the invention tailors the natural frequency of the spar buoys to provide minimal response to the actions of waves on the body of water for which it is intended. It further can employ multiple levels of articulation for the purpose of motion isolation of the upper platform for the conduct of motion sensitive operations while afloat. Clustering spar buoys under articulated footings in groups of three or more allows for a high load capacity while maintaining a tuned frequency response to the action of waves. Lateral and upward displacement of ballast, involving a lateral and upward displacement of the ballast, is useful in controlling direction the spar buoys will swing up and down while in transition. Thruster arrangement of this invention provides individual control of each buoy cluster and endows the vessel with unique modes of locomotion not seen in traditional surface ships. And the upright vessel may travel in any direction without re-orienting the platform. The retracted horizontal configuration navigates more like traditional surface vessels but has a unique appearance resembling something from science fiction.
[0069] The need to conduct motion sensitive operations at sea is increasing in the fields of space launch and recovery, oil exploration, aquaculture, international business, trade, finance, and travel and leisure. Additionally, motion isolated platforms will open possibilities for individuals to work in, or enjoy, nautical settings without the concern for motion sickness.
[0070] Many regions of the world are in need of new living space which will not increase pressure on terrestrial eco systems. The invention of a stable, robust, marine platform capable of handling the most severe wind and waves while providing occupants a low motion environment will be of tremendous value. Civil, business, research, and military uses of such a platform abound. This makes the described arrangement for supporting a stable floating platform upon spar buoy clusters using multiple levels of articulated footings unique and valuable.
[0071] The illustrated embodiments are only examples of the present invention and, therefore, are non-limitive. It is to be understood that many changes in the particular structure, materials, and features of the invention may be made without departing from the spirit and scope of the invention. Therefore, it is Applicant's intention that his patent rights not be limited by the particular embodiments illustrated and described herein, but rather by the following claims interpreted according to accepted doctrines of claim interpretation, including the Doctrine of Equivalents and Reversal of Parts.