WAVE ATTENUATING LARGE OCEAN PLATFORM

• US 20110174206A1
• Filed: 01/19/2010
• Published: 07/21/2011
• Est. Priority Date: 01/19/2010
• Status: Abandoned Application

• Current Assignee: PCCI, Inc.
• Original Assignee: PCCI, Inc.
• Inventors: Kupersmith, John A.
• Application Number:
  US12/689,849
• Publication Number:
  US 20110174206A1
• Time in Patent Office: Days
• US Class Current: 114/125
• CPC Class Codes: B63B 35/44 Floating buildings, stores, drilling platforms, or workshops, e.g. carrying water-oil separating devices construction methods for floating offshore platforms B63B75/00

Abstract

A large deck area floating platform with wave attenuating outriggers provides equivalent payload and deck operating area to a fixed, piled, and jacketed platform alternative for coastwise and offshore applications. The floating platform integrates large deck areas for industrial applications with a main ship-shaped hull and a submersible system of outriggers and column risers to form a stable, transportable, and structurally sound industrial facility that may be tuned hydro-dynamically to attenuate wave forces on the moored structure. The platform provides from 2 to 10 acres of weather deck and associated superstructure space, a ship-like hull, and direct subsea access via enclosed areas between the main hull and outriggers. Through the medium of differential ballasting, the displacement and freeboard of the facility may be adjusted to maintain hydro-dynamic tuning for changing wave conditions or to provide additional freeboard for storm survival.

Claims

1. A buoyant structure, comprising

a hull,

one or more decks supported by the hull,

surface piercing vertical columns, and

submersible horizontal outriggers attaching the surface piercing vertical columns to the hull.

2. The buoyant structure of claim 1, wherein the hull comprises a principal main hull and hull sections, wherein the principal main hull is a longitudinal ship-like floating structure and the hull sections are attached orthogonally to the principal main hull near its midship.

3. The buoyant structure of claim 1, further comprising one or more mooring stations at one or more ends of the hull.

4. The buoyant structure of claim 1, further comprising wave absorbing permeable cell facings on sides of the hull or submersible horizontal outriggers.

5. The buoyant structure of claim 1, further comprising ballast tanks in the hull and submersible horizontal outriggers, wherein differential ballasting can be used to adjust the displacement and freeboard of the buoyant structure to maintain hydro-dynamic tuning for changing wave conditions or to provide additional freeboard for storm survival, or to maintain constant displacement at variations of hull and deck loading.

6. The buoyant structure of claim 1, wherein the one or more decks comprise four independent deck structures.

7. The buoyant structure of claim 1, wherein a sheltered pool of water is formed in an area enclosed between the hull and submersible horizontal outriggers and surface piercing vertical columns, allowing direct subsea access.

8. The buoyant structure of claim 1, wherein the submersible horizontal outriggers are submerged to a depth that tunes them hydrodynamically to reduce their coefficient of wave transmission in a given wave climate and prevailing sea condition.

9. The buoyant structure of claim 1, further comprising crane pedestals located atop the surface piercing vertical columns for over-the-water cargo handling operations.

10. The buoyant structure of claim 1, wherein the hull comprises a structure that is ship-like in principal dimensions, having a relatively large length to beam ratio and a sufficient depth to draft ratio to provide for variable payloads and depth of submergence.

11. The buoyant structure of claim 1, wherein the hull comprises integral structural bossing used to attach the submersible horizontal outriggers to the hull.

12. The buoyant structure of claim 1, wherein the location and cross sectional area of the surface piercing vertical columns provide the optimal transverse and longitudinal metacentric heights to optimize the longitudinal and transverse stability of the buoyant structure, accounting for the overall mass center of gravity of the buoyant structure, such that the natural period of the buoyant structure'"'"'s oscillating motion falls outside the range of predominant wave periods in a selected operational setting.

13. The buoyant structure of claim 1, further comprising box girders connecting upper ends of the surface piercing vertical columns to the main hull, forming a top flange of the buoyant structure to transmit and absorb hull girder and secondary shear and moment forces caused by hydrostatic and dynamic loads, where the submersible horizontal outriggers form a corresponding lower flange.

14. The buoyant structure of claim 13, wherein the box girders each form the upper chord of a truss system with a large diameter pipe or rectangular steel box girder forming the lower chord of the truss. comprise a bottom chord structure of large diameter pipe and other truss components.

15. The buoyant structure of claim 13, wherein the box girders and associated decking run from the extreme port to extreme starboard side of the buoyant structure as well as longitudinally forward and aft, thus providing structural continuity to both lateral and transverse floating platform shear and bending.

16. The buoyant structure of claim 13, wherein the submersible horizontal outriggers and box girders are tied together to form an array of load carrying members.

17. The buoyant structure of claim 13, wherein the one or more decks comprise platform decking running between the box girders.

18. The buoyant structure of claim 17, wherein the one or more decks further comprises a superstucture of decking atop the platform decking, which incorporates industrial, power, hydrocarbon or chemical processing facilities, test and evaluation targets, ocean or wind energy recovery devices, or aviation operating platforms and hangars.

19. The buoyant structure of claim 1, wherein six of the submersible horizontal outriggers are attached forward, amidships and aft along the hull on port and starboard sides, orthogonal to the hull'"'"'s longitudinal axis of symmetry, wherein the surface piercing vertical columns are attached at lateral outboard terminations of the submersible horizontal outriggers, and wherein four of the submersible horizontal outriggers tie the columns together longitudinally, so that the surface piercing vertical columns are attached at a fixed distance from the hull laterally and among themselves longitudinally by the submersible horizontal outriggers.

20. The buoyant structure of claim 1, wherein four of the submersible horizontal outriggers are attached forward and aft along the principal main hull on port and starboard sides, orthogonal to the hull'"'"'s longitudinal axis of symmetry, wherein the surface piercing vertical columns are attached at lateral outboard terminations of the submersible horizontal outriggers, and wherein four of the submersible horizontal outriggers tie the columns longitudinally to the hull sections, so that the surface piercing vertical columns are attached at a fixed distance from the hull laterally and from the hull sections longitudinally by the submersible horizontal outriggers.

21. The buoyant structure of claim 1, wherein the submersible horizontal outriggers and surface piercing vertical columns are formed into elbow assemblages, each elbow assemblage consisting of a single surface piercing vertical column and two submersible horizontal outriggers attached to the single surface piercing vertical column and oriented orthogonally with respect both to the single surface piercing vertical column and to each other.

22. The buoyant structure of claim 1, wherein the one or more decks comprise a multilevel deck superstructure, wherein the submersible horizontal outriggers are supported at mid span by diagonal lower chord truss bracing tied into the surface piercing vertical columns at the multilevel deck superstructure.

23. The buoyant structure of claim 1, wherein the hull comprises redundant internal bulkheads that enhance survivability of the structure in case of flooding due to hull damage.

24. The buoyant structure of claim 1, wherein the hull comprises tankage and piping for liquid or gas storage.

25. The buoyant structure of claim 1, further comprising accommodation, recreation and office facilities either in a deckhouse or below deck.

26. The buoyant structure of claim 1, wherein the hull comprises storage or ballast tanks, internal accommodation spaces, machinery, and electrical and mechanical equipment.

27. A method of dissipating wave forces before they reach the hull of the buoyant structure of claim 21, comprising operationally adjusting freeboard or depth of the elbow assemblages to break wave crests.

28. A method of controlling dynamics of the buoyant structure of claim 1, comprising using differential ballasting to adjust the displacement and freeboard of the buoyant structure to maintain hydro-dynamic tuning for changing wave conditions or to provide additional freeboard for storm survival, or to maintain constant displacement at variations of hull and deck loading.

29. The buoyant structure of claim 14, further comprising tubular vertical and diagonal braces, wherein trusses connect orthogonally at “

K”

type joints to provide bi-directional load bearing capacity.