Method and apparatus for the offshore installation of multi-ton packages such as deck packages and jackets
First Claim
1. A catamaran work barge apparatus comprising:
- a) a pair of barges, each defining a base that can support a large multi-ton load;
b) a work platform supported respectively by the barges that can be positioned next to a package to be lifted, for forming a load transfer between the barges and the package to be lifted;
c) a plurality of diagonally extending lift booms, each lift boom having a lower end attached to a barge and an upper end that can be attached to the work platform;
d) lower connection members for forming attachments between the barges and the work platform;
e) each boom having a free end with a lifting end portion; and
f) a receptacle attached to the work platform that receives the boom lifting free end portion.
3 Assignments
0 Petitions
Accused Products
Abstract
A method and apparatus for the installation or removal of large multi-ton prefabricated deck packages includes the use of usually two barges defining a base that can support a large multi-ton load. A variable dimensional truss assembly is supported by the barge and forms a load transfer interface between the barge and the deck package. Each boom has a lifting end portion with a roller that fits a receptacle on the package. Tensile connections form attachments between the deck package and barge at a lower elevational position. The variable dimension truss includes at least one member of variable length, in the preferred embodiment being a winch powered cable that can be extended and retracted by winding and unwinding the winch.
67 Citations
20 Claims
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1. A catamaran work barge apparatus comprising:
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a) a pair of barges, each defining a base that can support a large multi-ton load; b) a work platform supported respectively by the barges that can be positioned next to a package to be lifted, for forming a load transfer between the barges and the package to be lifted; c) a plurality of diagonally extending lift booms, each lift boom having a lower end attached to a barge and an upper end that can be attached to the work platform; d) lower connection members for forming attachments between the barges and the work platform; e) each boom having a free end with a lifting end portion; and f) a receptacle attached to the work platform that receives the boom lifting free end portion. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
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10. A method for the offshore maintenance of a fixed offshore structure comprising the steps of:
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a) transporting a work platform to a desired site of the fixed offshore structure with a pair of barges that are spaced apart and generally parallel; b) attaching a lifting assembly to the work platform at multiple positions including positions that are at least on generally opposite sides of the work platform and at upper and lower positions on the work platform respectively, the lifting assembly including a lower chord normally in tension during the lifting process and a diagonally extending boom member chord normally in compression during the lifting process; c) wherein in step "b" the lifting assembly further includes a plurality of opposed lifting booms, each connected by at least one lifting end portion to a receptacle on the work platform; and d) using the work platform to perform maintenance on the fixed offshore structure. - View Dependent Claims (11, 12, 13, 14, 15)
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16. A method of repair or salvage of an offshore structure, comprising the steps of:
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a) providing a work platform; b) attaching a lifting assembly to the work platform at multiple elevational positions on the platform, including upper and lower positions and at the positions that are at least on generally opposite sides of the work platform; c) wherein the lifting assembly in step "b" includes opposed floating barges having diagonally extending lifting booms thereon connected at their upper ends with a lifting end portion to a receptacle on the work platform; d) structurally supporting each of the lifting booms at the lower end portion thereof with one of the barges, each boom being pivotally attached to its barge; e) wherein the work platform has receptacles thereon each with a downwardly oriented recess that receives the lifting end portion of a boom as the boom inclination increases relative to the deck of the barge; and f) supporting the work platform with fixed length chords of each lifting assembly so that combination of barges and platform only pivot at the base of each boom.
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17. A method of repair or salvage of an offshore structure, comprising the steps of:
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a) providing a work platform; b) attaching a lifting assembly to the work platform at multiple elevational positions on the platform, including upper and lower positions and at the positions that are at least on generally opposite sides of the work platform; c) wherein the lifting assembly in step "b" includes opposed floating barges having diagonally extending lifting booms thereon connected at their upper ends with a lifting end portion to a receptacle on the work platform; d) structurally supporting each of the lifting booms at the lower end portion thereof with one of the barges, each boom being pivotally attached to its barge; e) wherein the work platform has at least one powered lift cable thereon; and f) lifting the offshore structure with the powered lift cable.
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18. A method of repair or salvage of an offshore structure, comprising the steps of:
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a) providing a work platform; b) attaching a lifting assembly to the work platform at multiple elevational positions on the platform, including upper and lower positions and at the positions that are at least on generally opposite sides of the work platform; c) wherein the lifting assembly in step "b" includes opposed floating barges having diagonally extending lifting booms thereon connected at their upper ends with a lifting end portion to a receptacle on the work platform; d) structurally supporting each of the lifting booms at the lower end portion thereof with one of the barges, each boom being pivotally attached to its barge; e) wherein the work platform has a plurality of powered lift cables thereon; and f) lifting the offshore structure with the powered lift cables.
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19. A method for the offshore maintenance of a fixed offshore structure comprising the steps of:
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a) transporting a work platform to a desired site of the fixed offshore structure with a pair of barges that are spaced apart and generally parallel; b) attaching a lifting assembly to the offshore structure at multiple positions including positions that are at least on generally opposite sides of the offshore structure, and at upper and lower positions on the offshore structure respectively, the lifting assembly including a lower chord normally in tension during the lifting process and a diagonally extending boom member chord normally in compression during the lifting process; c) wherein in step "a" the lifting assembly further includes a plurality of opposed lifting booms, each connected by at least one lifting end portion to a receptacle on the work platform; and d) lifting the offshore structure with the work platform.
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20. A method for the offshore maintenance of a fixed offshore structure comprising the steps of:
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a) transporting a work platform to a desired site of the fixed offshore structure with a pair of barges that are spaced apart and generally parallel; b) attaching a lifting assembly to the offshore structure at multiple positions including positions that are at least on generally opposite sides of the offshore structure, and at upper and lower positions on the offshore structure respectively; c) wherein in step "b" the lifting assembly further includes a plurality of opposed lifting booms, each connected by at least one lifting end portion to a receptacle on the work platform; and d) using the work platform to perform maintenance on the fixed structure.
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Specification