Method and apparatus for the offshore installation of multi-ton packages such as deck packages and jackets
First Claim
1. A lifting apparatus for lifting a multi-ton package such as a deck package, sunken vessel, or offshore jacket, comprising:
- a) a pair of barges, each defining a base that can support a large multi-ton load;
b) a truss supported respectively by the barges and positioned about the periphery of the package for forming a load transfer between the barges and the package to be lifted;
c) each said truss including at least one diagonally extending lift boom, each lift boom having a lower end attached to a barge and an upper end that can be attached to the deck package;
d) lower connections for forming attachments of the truss to the package;
e) each boom having a free end with a lifting end portion;
f) a receptacle attached to the package that receives the lifting free end portion;
g) wherein the lifting end portion engages the receptacle as the boom angle of inclination is gradually increased; and
h) means for raising and lowering the combination of the truss and the supported package.
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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.
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Citations
20 Claims
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1. A lifting apparatus for lifting a multi-ton package such as a deck package, sunken vessel, or offshore jacket, comprising:
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a) a pair of barges, each defining a base that can support a large multi-ton load; b) a truss supported respectively by the barges and positioned about the periphery of the package for forming a load transfer between the barges and the package to be lifted; c) each said truss including at least one diagonally extending lift boom, each lift boom having a lower end attached to a barge and an upper end that can be attached to the deck package; d) lower connections for forming attachments of the truss to the package; e) each boom having a free end with a lifting end portion; f) a receptacle attached to the package that receives the lifting free end portion; g) wherein the lifting end portion engages the receptacle as the boom angle of inclination is gradually increased; and h) means for raising and lowering the combination of the truss and the supported package. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
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10. A method for the offshore lifting of a multi-ton package such as a deck package, sunken vessel or jacket, comprising the steps of:
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a) transporting a lifting assembly to a desired site of the package, deck package, or jacket; b) attaching the lifting assembly to the package at multiple positions including positions that are at least on generally opposite sides of the package, and at upper and lower positions on the package respectively, the lifting assembly including at least three chords, including a horizontal chord normally in tension during the lifting process which has a variable length and a diagonally extending chord normally in compression during the lifting process; c) wherein in step "a" the lifting assembly further includes two opposed lifting booms, each connected by at least one lifting end portion to a receptacle on the package; d) laterally adjusting the position of at least a portion of the lifting end portion during engagement with the receptacle in order to properly align the lifting end portion with the corresponding receptacle; e) structurally supporting the lifting assembly with one or more lift barges; and f) lifting the package upon by changing the length of the horizontal chord of the lifting assembly. - View Dependent Claims (11, 12, 13, 14, 15, 16, 17)
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18. A method for the offshore lifting a multi-ton such as a deck package, jacket or submerged vessel, comprising the steps of:
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a) transporting a lifting assembly to a desired site having the deck package, jacket or submerged vessel; b) attaching the lifting assembly to the package at multiple elevational positions on the package, including upper and lower positions that are at least on generally opposite sides of the package; c) wherein the lifting assembly 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 deck package; 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 package 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) elevating the package by changing the length of the horizontal chord of each lifting assembly so that the lifting end portion gradually elevates to engage the downwardly oriented recess.
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19. A lifting apparatus for lifting a multi-ton package such as a deck package, sunken vessel, or offshore jacket, comprising:
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a) a pair of barges, each defining a base that can support a large multi-ton load; b) each barge having a truss supported thereon and wherein the barges can be positioned about the periphery of the package for forming a load transfer between the barges and the package to be lifted; c) each said truss including at least one diagonally extending lift boom, each lift boom having a lower end attached to a barge and an upper end that can be attached to the deck package; d) lower connections for forming attachments of the truss to the package; e) each boom having a free end with a lifting end portion; f) a receptacle attached to the package that receives the lifting free end portion; g) wherein the lifting end portion engages the receptacle as the boom angle of inclination is gradually increased; and h) a power unit for raising and lowering the combination of the truss and the supported package.
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20. A lifting apparatus for lifting a multi-ton package such as a deck package, sunken vessel, or offshore jacket, comprising:
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a) a pair of barges, each defining a base that can support a large multi-ton load; b) each barge having a truss supported thereon and wherein the barges can be positioned about the periphery of the package for forming a load transfer between the barges and the package to be lifted; c) each said truss including a plurality of diagonally extending lift boom, each lift boom having a lower end attached to a barge and an upper end that can be attached to the deck package; d) lower connections for forming attachments of the truss to the package; e) each boom having a free end with a lifting end portion; f) a receptacle attached to the package that receives the lifting free end portion; g) wherein the lifting end portion engages the receptacle as the boom angle of inclination is gradually increased; and h) a power unit for raising and lowering the combination of the truss and the supported package.
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Specification