COLUMN STABILIZED STINGER

• US 3,685,305 A
• Filed: 08/17/1970
• Issued: 08/22/1972
• Est. Priority Date: 08/17/1970
• Status: Expired due to Term

• Current Assignee: Samuel H. Lloyd III
• Original Assignee: Samuel H. Lloyd III
• Inventors: Lloyd, Samuel H. III
• Primary Examiner(s): Shapiro, Jacob
• Application Number:
  US05/064,267
• Time in Patent Office: 736 Days
• Field of Search: 61/72.3,72.4,72.1 114/.5F
• US Class Current: 405/166
• CPC Class Codes: B63B 1/107 Semi-submersibles; Small waterline area multiple hull vessels and the like, e.g. SWATH
• CPC Class Codes: B63B 35/03 Pipe-laying vessels laying pipes under water F16L1/12
• CPC Class Codes: B63B 35/04 Cable-laying vessels
• CPC Class Codes: F16L 1/225 Stingers

Abstract

The stinger includes a base structure having a plurality of upstanding stabilizing columns on opposite sides of its pitch and roll axes and carrying pipeline supports which permit translational movement of the pipeline relative to the stinger. The stinger is pivotably secured behind the pipelaying barge and is ballasted from a low draft condition with the base structure having freeboard to a high draft condition. The pipeline supports progressively decrease in height above the base structure from the end of the segment nearest the barge whereat the pipeline is supported in the air toward the opposite end whereat the aft pipeline support disposes the pipeline below the mean waterline. The pipeline centerline extending along the supports defines a radius of curvature at least equal to and preferably much greater than the minimum allowable radius of curvature for the pipeline. The stinger is preferably configured such that the combined natural frequency of the stinger and pipeline match as nearly as possible the natural frequency of the pipelaying barge.

Claims

1. A flotation member for laying pipeline on an underwater surface from a floating vessel having a pipeline work deck elevated above the mean waterline comprising;

an elongated base structure comprised of a pair of transversely spaced hulls, at least a portion of said hulls converging toward one another in one of the fore and aft directions;

a plurality of elements upstanding from said hulls with at least a portion of said elements comprised of a plurality of stabilizing columns located on opposite sides of the pitch and roll axes of the member;

means for submerging said base structure and portions of said upstanding elements below the waterline to obtain a high draft floating condition, the displacement of the submerged base structure and portions of said upstanding elements being sufficient to maintain the member buoyant in a pipeline portion supporting condition with the mean waterline located intermediate the height of said columns;

coupling means carried by said base structure adjacent its forward end for pivotally coupling the flotation member to the pipelaying vessel; and

means carried by said flotation member for supporting a portion of a pipeline for translational movement therealong, said pipeline support means being located above said base structure at elevations of decreasing height relative to said base structure in a forward to aft direction along said flotation member, the pipeline support means being adapted to receive pipeline payed out from the elevated work deck of the pipelaying vessel.

2. Apparatus according to claim 1 including means for varying the submergence of the flotation member in the high draft condition to alter the natural period of the flotation member to preclude amplification of flotation member motion due to interaction of wave and flotation member motion.

3. Apparatus according to claim 1 wherein said stabilizing columns have a substantially uniform cross-sectional area throughout their height.

4. Apparatus according to claim 1 wherein said submerging means includes means for ballasting and deballasting said base structure.

5. Apparatus according to claim 4 wherein each of said hulls include a plurality of compartments, valve means associated with said compartments for introducing water ballast into and expelling water ballast from said compartments.

6. Apparatus according to claim 1 wherein said support means comprises a plurality of rollers disposed at longitudinally spaced positions along said stinger and lying substantially coincident with the longitudinal centerline of the stinger.

7. Apparatus according to claim 6 wherein at least a pair of said columns are carried by each of said hulls, a plurality of support struts extending between laterally adjacent columns, said rollers being disposed on said support struts.

8. Apparatus according to claim 1 including said vessel, said coupling means coupling said flotation member to the aft end of said vessel to position the flotation member for receiving pipeline payed out from said vessel.

9. Apparatus according to claim 8 wherein said vessel has a work area adjacent one side of the vessel for assembling pipe sections, said member being coupled to said vessel to lie in substantial longitudinal alignment with said one vessel side.

10. Apparatus according to claim 8 wherein said vessel has a work area substantially along the centerline of said vessel, said member being coupled to said vessel such that the centerlines of said vessel and said member lie in substantial longitudinal alignment one with the other.

11. Apparatus according to claim 8 wherein said vessel includes a base structure and a plurality of columns upstanding from said base structure, and means for ballasting and deballasting said vessel between high and low draft conditions, said vessel being column stabilized in the high draft condition.

12. Apparatus according to claim 11 wherein said vessel has a work area adjacent one side thereof for assembling pipe sections, said vessel hull structure including a pair of elongated hulls spaced one from the other on opposite sides of said vessel, and means carried by the aft portion of the one hull on the same side of said vessel as said work area and cooperable with said coupling means on said stinger for releasably connecting said flotation member to said vessel.

13. Apparatus according to claim 11 wherein said vessel has a work area substantially along the centerline of said vessel for assembling pipe sections, said vessel hull structure including a pair of elongated hulls spaced one from the other on opposite sides of said vessel, and means carried by the aft portions of said hulls and cooperable with said coupling means on said flotation member for releasably connecting said flotation member to said vessel.

14. Apparatus according to claim 8 wherein the natural period of said flotation member and the pipeline portion carried thereby substantially match the natural frequency of said vessel.

15. Apparatus according to claim 8 wherein said vessel and said flotation member and pipeline portion carried thereby have predetermined natural periods, and means for selectively ballasting and deballasting the stinger to substantially match the natural period of the stinger and pipeline portion carried thereby with the natural period of the vessel.

16. Apparatus according to claim 1 wherein at least a pair of said columns are carried by each of said hulls, said base structure being configured to float the member in a low draft condition with the base structure having freeboard, said submerging means including means for ballasting said hull members to change the draft of the members from said low draft condition to said high draft condition.

17. Apparatus according to claim 1 wherein said base structure includes a keel spaced below said hulls, and means connecting said hulls and said keel one to the other.

18. Apparatus for laying pipeline on an underwater surface comprising;

a floating vessel having a pipeline work deck elevated above the mean waterline;

a flotation member having an elongated base structure;

a plurality of elements upstanding from said base structure with at least a portion of said elements comprised of a plurality of stabilizing columns located on opposite sides of the pitch and roll axes of said flotation member;

means for submerging said base structure and portions of said upstanding elements below the waterline to obtain a high draft floating condition, the displacement of the submerged base structure and portions of said upstanding elements being sufficient to maintain the flotation member buoyant in a pipeline portion supporting condition with the mean waterline located intermediate the height of said columns;

means carried by said base structure adjacent its forward end pivotally coupling said pipelaying vessel and said flotation member one to the other; and

means carried by said flotation member for supporting a portion of a pipeline for translational movement therealong, said pipeline support means being located above said base structure at elevations of decreasing height relative to said base structure in a forward to aft direction along said flotation member, the pipeline support means being adapted to receive pipeline payed out from the elevated work deck of said vessel;

said flotation member comprising the sole means for supporting the pipeline as it is payed out from said vessel.