# US 5,704,731 A · Multipurpose offshore modular platform > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 5,704,731 A - Document ID: US5704731A - Status: Granted - Kind: A - Application number: 08/644,570 - Filed: 1996-05-10 - Granted: 1998-01-06 - Earliest claimed: 1995-04-07 - Assignees: San Tai International Corporation - Inventors: Yen T. Huang - Web page: https://patentgrep.com/patent/US5704731A ## CPC - B63B 35/4413: {Floating drilling platforms, e.g. carrying water-oil separating devices} - B63B 1/041: {with disk-shaped hull} - B63B 3/04: with permanently-connected sub-units - B63B 5/24: made predominantly of plastics {(surf boards B63B32/57)} - B63B 21/502: {by means of tension legs} - B63B 35/00: Vessels or similar floating structures specially adapted for specific purposes and not otherwise provided for - B63B 35/50: Vessels or floating structures for aircraft (aircraft carriers B63G11/00; flying-boat hulls, other flotation means for aircraft B64) - B63B 2001/044: {with a small waterline area compared to total displacement, e.g. of semi-submersible type} - B63B: SHIPS OR OTHER WATERBORNE VESSELS; EQUIPMENT FOR SHIPPING (arrangements of vessel ventilation, heating, cooling, or air-conditioning B63J2/00; floating substructures as supports of dredgers or soil-shifting machines E02F9/06) ## Abstract Modular floating structures suitable for supporting offshore oil drilling and production platforms may be fabricated utilizing a Y-shaped joint interconnecting plural legs of a space frame. The space frame may be made up of plural frame members where each corner of the frame includes a Y-shaped joint. Stable offshore floating structures for drilling and production platforms may utilize the integral space frames in a truncated dodecahedral, inverted pyramid or tetrahedral configuration. The Y-shaped joint may be formed of three channel members each having opposed legs which may be secured to the opposed legs of the other channel members in a back-to-back or face-to-face configuration to form the Y-shaped joint. The channel members may be fabricated of flat plate folded and cut along predetermined lines to form the channel members. If the channel members are secured to each other face-to-face, they may form hollow flotation chambers suitable for use with the floating structures. Cylindrical tanks can be used as modular components. The Y-shaped joints may be easily fabricated on site or prefabricated and nested for ease of storage and transport. The Y-shaped joints may be formed as flexible inflatable members interconnected by coupling members to form a rigid floating structure. The Y-shaped joints and connecting leg portions may also be used to temporarily store fluids, such as crude oil, produced from subsea wells connected to the floating structures. The Y-shaped joints may be deflated for transportation of the structure on the sea. ## Claims ### Claim 1 A floating structure, particularly adapted to support a platform for disposition in a water environment such as an open sea, said floating structure comprising: a plurality of depending interconnected space frames, each of said space frames comprised of elongated depending legs and plural Y-shaped joints interconnecting said legs, each said Y-shaped joint comprised of a vertex and only three segments, each segment being connected at one end thereof to said vertex and two of said segments being connected at the other ends thereof to corresponding legs in the same space frame, and the third segment being connected to a leg in an adjacent space frame; anchor means connected to at least some of said space frames for anchoring said structure in the open ocean; and flotation chambers for said floating structure to maintain said floating structure buoyant in the sea, said chambers being associated at least with said legs. ### Claim 2 (depends on 1) The invention set forth in claim 1 wherein: said floating structure is formed of a generally horizontally extending space frame interconnected with said depending space frames and supporting said platform thereon. ### Claim 3 (depends on 2) The invention set forth in claim 2 wherein: said space frames are pentagonal having leg portions interconnected by Y-shaped joints and each of said Y-shaped joints has three branch arm portions wherein each of two branch arm portions form an angle of about 108.degree. between each other. ### Claim 4 (depends on 2) The invention set forth in claim 2 wherein: said depending space frames are triangular having leg portions interconnected by Y-shaped joints and each of said Y-shaped joints has three branch arm portions wherein each of two branch arm portions form an angle of about 60.degree. between each other and a third angle between two branch arm portions of about 90.degree.. ### Claim 5 (depends on 2) The invention set forth in claim 2 wherein: said depending space frames are pentagonal and hexagonal and have leg portions interconnected by Y-shaped joints, each of said Y-shaped joints has three branch arm portions wherein each of two branch arm portions form an angle of about 120.degree. between each other and a third angle between two branch arm portions of about 108.degree.. ### Claim 6 (depends on 2) The invention set forth in claim 2 wherein: said space frames defined by said plural Y-shaped joints interconnecting generally horizontally extending leg portions comprise triangles and said floating structure comprises a tetrahedral structure wherein each of said Y-shaped joints is defined by branch portions forming angles of 60.degree. between each other, respectively. ### Claim 7 (depends on 1) The invention set forth in claim 1 wherein: said anchor means includes one of tension leg members secured to said floating structure and catenary anchor leg members connected to said floating structure at spaced apart points thereon, respectively. ### Claim 8 (depends on 1) The invention set forth in claim 1 wherein: said floating structure includes a generally horizontally disposed space frame and said depending legs extend from said generally horizontally disposed space frame to Y-shaped joints interconnecting said structure with a platform supported thereby and above the surface of the sea. ### Claim 9 (depends on 1) The invention set forth in claim 1 wherein: said floating structure forms a pyramid structure having a space frame defined by plural Y-shaped joints interconnecting generally horizontally extending leg portions and depending leg portions. ### Claim 10 (depends on 9) The invention set forth in claim 9 wherein: said floating structure includes a generally rectangular space frame supporting a platform above said generally horizontally extending leg portions and said depending leg portions extend to a quadrajoint to form an inverted pyramid. ### Claim 11 (depends on 9) The invention set forth in claim 9 wherein: said floating structure forms a tetrahedron having a triangular space frame disposed generally horizontally for supporting a platform thereon, and said floating structure includes triangular depending space frames extending from said horizontally disposed space frame. ### Claim 12 (depends on 1) The invention set forth in claim 1 wherein: said floating structure includes one of a generally hexagonal and a generally pentagonal horizontally disposed space frame and said depending legs extend from said horizontally disposed space frame to Y-shaped joints defining at least one of plural pentagonal space frames and plural hexagonal space frames, said space frames further comprising said hollow structural members forming flotation space for said floating structure to maintain said floating structure buoyant in the sea. ### Claim 13 (depends on 12) The invention set forth in claim 12 including: coupler means extending between said Y-shaped joints comprising cooperating coupler members operable to interconnect respective ones of said branch portions of said Y-shaped joints. ### Claim 14 (depends on 13) The invention set forth in claim 13 wherein: said coupler members each comprise a coupler sleeve having opposed tapered bores and said Y-shaped joints each have cooperating tapered coupler members operable to be inserted in said sleeve and interconnected with said sleeve by cooperating connecting ring members residing in circumferential grooves formed in said sleeve and in said coupler members of said Y-shaped joints, respectively. ### Claim 15 (depends on 13) The invention set forth in claim 13 wherein: said coupler means extending between said Y-shaped joints, each comprise a threaded coupling sleeve threadedly engageable with cooperating threaded coupler members formed on respective ones of said branch portions of said Y-shaped joints. ### Claim 16 (depends on 13) The invention set forth in claim 13 wherein: said coupler means extending between said Y-shaped joints, each comprise a threaded member engageable with cooperating threaded portions of respective ones of said branch portions of said Y-shaped joints. ### Claim 17 (depends on 1) The invention set forth in claim 1 wherein: said Y-shaped joints and said depending legs are formed of flexible material and said Y-shaped joints and said depending legs are adapted to be filled with pressure fluid to cause said space frames to be substantially rigid and to form flotation chambers for said floating structure. ### Claim 18 (depends on 17) The invention set forth in claim 17 wherein: said Y-shaped joints include respective branch portions and remotely controllable fluid control valves for valving pressure fluid into and from said legs and said branch portions of said Y-shaped joints to control the erection and rigidity of said space frames, respectively. ### Claim 19 (depends on 1) The invention set forth in claim 1 wherein: said anchor means includes one of tension leg members, taut anchor leg members and catenary anchor leg members secured to said Y-shaped joints, respectively. ### Claim 20 (depends on 1) The invention set forth in claim 1 wherein: said floating structure includes an inner and outer skin defining a closable space forming buoyancy means for supporting said floating structure in the sea. ### Claim 21 (depends on 1) The invention set forth in claim 1 wherein said flotation chambers comprise at least part of said depending legs. ### Claim 22 (depends on 1) The invention set forth in claim 1 and further including ballast chambers for said floating structure to maintain said floating structure upright and to lower the center of gravity thereof. ### Claim 23 (depends on 22) The invention set forth in claim 22 wherein said ballast chambers comprise at least part of said depending legs.