Method and apparatus for the offshore installation of multi-ton packages such as deck packages and jackets

Information

  • Patent Grant
  • 6364574
  • Patent Number
    6,364,574
  • Date Filed
    Tuesday, November 21, 2000
    24 years ago
  • Date Issued
    Tuesday, April 2, 2002
    22 years ago
  • Inventors
  • Examiners
    • Dang; Hoang
    Agents
    • Garvey, Smith, Nehrbass & Doody, LLC
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.
Description




STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT




Not applicable




REFERENCE TO A “MICROFICHE APPENDIX”




Not applicable




BACKGROUND OF THE INVENTION




1. Field of the Invention




The present invention relates to the placement of large multi-ton prefabricated deck packages (e.g. oil and gas platforms, oil rigs) in an offshore environment upon a usually partially submerged jacket that extends between the seabed and the water surface. Even more particularly, the present invention relates to the use of a moving lifting assembly which is preferably barge supported that can place a very large deck package upon an offshore marine jacket foundation without the use of enormous lifting booms such as form a part of derrick barges, offshore cranes, and the like, and wherein opposed short booms are connected with a frame or compressive spreader members that enable use of suspended slings to lift the deck package




2. General Background




In the offshore oil and gas industry, the search for oil and gas is often conducted in a marine environment. Sometimes the search takes place many miles offshore. Oil and gas well drilling takes place in many hundreds of feet of water depth.




The problem of drilling oil wells offshore and then producing these wells has been solved in part by the use of enormous fixed-or floating platform structures with foundations that are mostly submerged, but usually extending a number of feet above the water surface. Upon this foundation (or “jacket”, tension leg platform (“TLP”), or SPAR, etc. as it is called in the art) there is usually placed a very large prefabricated rig or deck platform. The term “deck platform” as used herein should be understood to include any of a large variety of prefabricated structures that are placed on an offshore foundation to form a fixed or floating offshore platform. Thus, a “deck-platform” can include, e.g. a drilling rig, a production platform, a crew quarters, living quarters, or the like.




As an example of one offshore foundation, a supporting jacket is usually a very large multi-chord base formed of multiple sections of structural tubing or pipe that are welded together. Such jackets have been used for a number of years for the purpose of supporting large deck platforms in an offshore environment.




The jacket or foundation is usually prefabricated on land in a fabrication yard, preferably adjacent to a navigable waterway. The completed jacket can be placed upon a large transport barge so that it can be moved to the drill site where it will be placed upon the ocean floor. As an example, an offshore jacket can be several hundred feet in length. The size of the jacket is of course a function of the depth of water in which the rig will be placed. A five hundred (500) foot water depth at the drill site (or production site) will require a jacket which is approximately 500-550 feet tall. The jacket is usually partially submerged, with only a small upper portion of the jacket extending slightly above the water surface. An offshore jacket as described and in its position on the seabed can be seen, for example, in the Blight, et al U.S. Pat. No. 4,252,469 entitled “Method and Apparatus for installing integrated Deck Structure and Rapidly Separating Same from Supporting Barge Means.” Specifically, FIGS. 1, 2 and 3 of the Blight, et al patent show an offshore jacket on the seabed.




A small upper portion of the jacket extends above the water surface. This exposed portion of the jacket is the portion upon which the “deck platform” is placed and supported by. This upper portion of the jacket is usually equipped with a number of alignment devices which enhance the proper placement of the deck package on the jacket. Such alignment devices are referred to variously as stabbing eyes, sockets, or the like. The use of such alignment devices, sockets, or stabbing eyes can be seen in the Blight, et al U.S. Pat. Nos. 4,252,468 and 4,252,469 as well as in the Kansan U.S. Pat. No. 4,242,011. For purposes of background and reference, the Kansan U.S. Pat. No. 4,242,011 is incorporated herein by reference. The Blight, et al U.S. Pat. Nos. 4,252,469 and 4,252,468 are likewise each incorporated herein by reference.




Deck platforms or topsides can be extremely large and have correspondingly heavy weights. For example, it is not uncommon for a deck platform such as a drilling rig crew quarters, production platform or the like to be between five hundred and five thousand (500 and 5,000) tons gross weight. Topsides in excess of ten thousand (10,000) tons have been installed, and others that are being planned may weigh as much as thirty thousand (30,000) tons. Such enormous load values present significant problems in the placement of deck platforms on offshore jacket structures. First, the placement is done entirely in a marine environment. While the jacket can be laid on its side and/or floated into position, the platform is not a submersible structure, and must be generally supported in an upright condition above the water surface to prevent water damage to the many components that form a part of the drilling or production platform (such as electrical systems, wall constructions, and other portions that will be inhabited by individuals and used as oil and gas well drilling or production equipment).




The art has typically used enormous derrick barges for the purpose of setting or placing deck packages on jackets in an offshore environment. These derrick barges are large, rectangular barge structures with a high capacity lifting boom mounted at one end portion of the deck of the barge. The barge, for example might be three hundred to four hundred (300-400) feet in length, fifty to seventy five (50-75) feet in width, and twenty-five to fifty (25-50) feet deep. These figures are exemplary.




A derrick barge might have a lifting capacity of for example, two thousand (2,000) tons. For very large structures such as for example, a five thousand (5,000) ton deck package, two derrick barges can be used, each supporting one side portion of the deck platform with a multi-line lift system supported by an enormous structural boom extending high into the air above the package during the lift.




The boom simply works in the same way as an anchor lifting boom, namely the loadline raises and/or lowers the package into its proper position upon the jacket. While the use of such derrick barges has been very successful in the placing of offshore deck packages on jackets through the years, such derrick barges are generally limited in their capacity to packages of two thousand (2,000) tons or less. Further, derrick barges of such an enormous capacity are extremely expensive to manufacture and operate. Many thousand of dollars per hour as a cost of using such a device is not uncommon. Although there are five (5) or six (6) derrick barges that can lift in excess of six thousand (6,000) tons, they are extremely costly and limited as to the water depth in which they can operate.




However, when very large loads of, for example six thousand -ten thousand (6,000-10,000) tons are involved, the limitation of the derrick barge usually prohibits such a placement on an offshore jacket. The topside must then be pieced and finished offshore.




In U.S. Pat. No. 4,714,382 issued to Jon Khachaturian there is disclosed a method and apparatus for the offshore installation of multi-ton prefabricated deck packages on partially submerged jacket foundations. The Khachaturian patent uses a variable dimensional truss assembly is supported by the barge and forms a load transfer interface between the barge and the deck package. Upper and lower connections form attachments between the truss members and the deck package at upper and lower elevational positions on the deck package. 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. Alternate embodiments include the use of a hydraulic cylinder as an example.




An earlier patent, U.S. Pat. No. 2,598,088 issued to H.A. Wilson entitled “Offshore Platform Structure and Method of Erecting Same” discusses the placement of drilling structure with a barge wherein the legs of the drilling structure are placed while the drilling structure is supported by two barges. The Wilson device does note use truss-like lifting assemblies having variable length portions which are placed generally on opposite sides of the deck package. Rather, Wilson relates to a platform which is floated in place and the support legs are then placed under the floating platform. Thus, in the Wilson reference, an in-place underlying supporting jacket is not contemplated.




The Natvig, et al U.S. Pat. No. 3,977,346 discusses a method of placing a deck structure upon a building site such as a pier. The method includes the pre-assembly of a deck structure upon a base structure on land so that the deck structure extends outwardly over a body of water. Floating barges are provided for supporting the deck structure outwardly of the building site. The deck structure is then transferred to the supportive base structure by means of barges. The Natvig reference uses two barges which are placed on opposite sides of a platform with pedestal type fixed supports forming a load transfer member between the barges and the platform. However, the fixed pedestal of Natvig is unlike the truss-like lifting arrangement of applicant which include movable portions at least one of which can be of a variable length.




U.S. Pat. No. 4,249,618, issued to Jacques E. Lamy, discloses a method of working an underwater deposit comprising the following stages: a) constructing an positioning a platform structure, equipped before or after positioning with drilling devices and installations, b) executing drilling using these devices and installations, c) constructing and equipping, during stages a) and b), a production bridge fitted with devices and installations required for production, d) transporting the production bridge to, and positioning it on, said platform structure, and e) commencing production from deposit. The drilling bridge may remain in position on the platform structure during stages d) and e) or it may be removed to make way for the production bridge.




U.S. Pat. No. 4,744,697, issued to Anton Coppens, discloses a vessel that is provided for installing or removing a module on or from a support structure erected in a body of water. The vessel is able to suspend the module over the support structure by cranes enabling installation or removal of the module to be accomplished while the module is being suspended.




U.S. Pat. No. 5,037,241, issued to Stephen D. Vaughn et al. discloses an improved apparatus for setting a deck structure or other marine superstructure using a barge mounted cantilevered support structure. The cantilevered support structure is attached at one end of a floating vessel. The cantilevered support structure extends past the edge of the vessel and, in one embodiment, includes means for rotating parallel support members about the deck of the floating vessel permitting the cantilevered support structure to be raised and lowered while it remains substantially parallel with the top of the offshore platform enabling the superstructure to engage the top of a previously installed offshore platform in a synchronized manner. Alternatively, this superstructure may be aligned directly over the platform. A cantilevered drilling rig is then aligned over the cantilevered support structure and used to lift the deck structure or marine superstructure, permitting the vessel and cantilevered support structure to move. The drilling rig is then used to lower the marine superstructure onto the top of the previously installed offshore platform.




BRIEF SUMMARY OF THE INVENTION




The present invention provides an improved method and apparatus for the lifting and/or placement of a multi-ton package such as a deck package, jacket, or sunken vessel. Also the present invention provides an improved method and apparatus for the removal of a multi-ton package from a marine environment, water surface, or ocean floor (i.e., sunken vessel) or from an offshore jacket.




The present invention discloses an improvement to the variable dimension truss assembly disclosed in U.S. Pat. No. 4,714,382 incorporated herein by reference.




The apparatus includes one or more barges defining a base that supports the large multi-ton load of the deck package.




In the preferred embodiment, truss-like lifting device includes a barge mounted on each side of the deck package to be lifted during operation.




In the preferred embodiment, two barges are used respectively, each having at least one truss-like lifting device on its upper deck surface. The truss preferably includes inclined and opposed booms mounted respectively on each barge, and a horizontal chord member of variable length that employs a cable wound upon a winch on each barge so that the cross-sectional dimensions of the truss can be varied by paying out or reeling in cable from the winch.




The truss forms a load transfer between each barge and the package to be lifted (e.g., deck package, or jacket) and/or placed. Upper and lower connections are formed between the lifting truss and the deck package at respective upper and lower elevational positions.




Power is provided, preferably in the form of the winch and its cable mounted on each barge for changing the length of the horizontal chord, variable length member of the truss so that elevational position of the deck package with respect to the barge can be varied such as during a lifting or lowering of the package (such as to or from a jacket foundation).




In the method of the present invention, the multi-ton deck package is first transported on a transport barge to the site where it will eventually assist in the drilling oil and/or production of a well.




In the preferred embodiment, a lifting assembly is attached to the package on generally opposite sides of the package and at upper and lower positions.




One element of the truss-like lifting assembly preferably includes a movable horizontal chord portion which has a variable length. In the preferred embodiment, the movable portion is a winch powered cable extending from each winch to a padeye connection on the package (e.g., using sheaves) to be lifted or lowered, wherein the cable can be extended or retracted between the lift barge and the deck package being lifted or lowered.




In the preferred embodiment, two lift barges support respectively first and second pluralities of truss-like lifting assemblies which in combination with the package form an overall truss arrangement. That is, the deck package itself can form a portion of the truss during the lift (typically carrying tension), and may carry both compression and tension loads.




In the preferred embodiment, the truss-like lifting assemblies have multiple booms (e.g., four) on each barge that are connected at their upper end portions to the package using a boom lifting end portion that elevates to engage a receptacle on the package. An improved connection between the booms and package is provided that uses a specially configured lifting end portion on each boom and a corresponding number receptacles on the deck package (e.g., welded thereto).




The lifting end portions support the package and can elevate it above the surface of any transport barge, so that the transport barge can be removed as a support for packages such as jackets or deck packages. This allows the package to be placed vertically above a jacket foundation and aligned with the foundation so that the deck package can be placed upon the foundation by lowering. In the case of a jacket, the transport barge can be removed so that the jacket can be lowered into the water and floated prior to installation.




The present invention allows a dimensional change in the cross-sectional configuration of the truss with respect to a vertical cross section of the truss and provides a means of raising and lowering the selected package.











BRIEF DESCRIPTION OF THE DRAWINGS




For a further understanding of the nature, objects, and advantages of the present invention, reference should be had to the following detailed description, read in conjunction with the following drawings, wherein like reference numerals denote like elements and wherein:





FIG. 1

is a perspective view of the preferred embodiment of the apparatus of the present invention;





FIG. 2

is a partial perspective view of the preferred embodiment of the apparatus of the present invention;





FIG. 2A

is a partial sectional elevational view of the preferred embodiment of the apparatus of the present invention;





FIG. 3

is a perspective fragmentary view of the preferred embodiment of the apparatus of the present invention illustrating the lifting end portion thereof;





FIG. 4

is a sectional view taken along lines


4





4


of FIG.


3


;





FIG. 5

is a fragmentary perspective view of the preferred embodiment of the apparatus of the present invention illustrating the receptacle portion thereof;





FIG. 6

is a partial sectional elevational view of preferred embodiment of the apparatus of the present invention illustrating engagement of the boom lifting end portion and receptacle such as during lifting of a heavy deck package;





FIG. 7

is a fragmentary perspective view of the preferred embodiment of the apparatus of the present invention illustrating the bridle plate and variable length tensile member portions thereof; and





FIG. 8

is a perspective fragmentary view of the preferred embodiment of the apparatus of the present invention illustrating the boom and heel pin padeye portions thereof.











DETAILED DESCRIPTION OF THE INVENTION





FIGS. 1 and 2

show generally the preferred embodiment of the apparatus of the present invention designated generally by the numeral


10


in FIG.


1


. Lifting apparatus


10


utilizes a pair of spaced apart marine barges


11


,


12


each having a respective deck


13


,


14


. The barges


11


,


12


float on water surface


15


adjacent an underwater jacket


16


having its uppermost portion exposed in the form of a plurality of vertical columns


18


as shown in

FIGS. 1 and 2

.




The use of underwater jackets


16


for the purpose of supporting any number of offshore structures is well known in the art. Typically, a drilling platform, production platform, machine shop, storage facility, or like offshore structure is manufactured on land as a heavy deck package and then transported to a selected offshore marine location for placement on a jacket


16


. The jacket is also usually manufactured on land as a one-piece unit, towed to a selected site on a transport vessel such as a barge, and then transferred from the barge to the marine environment. The lower end portion of the jacket engages the ocean floor or seabed with the upper vertical columns


18


extending above the water surface


15


as shown in

FIGS. 1 and 2

. This procedure for placing jackets so that they can support a heavy deck package


17


in a marine environment is well known in the art.




In the past, placement of such deck package


17


upon the vertical columns


18


of a jacket


16


has been accomplished using large lifting devices known as derrick barges, a huge barge having a crane thereon with a multi-ton lifting capability.




In my prior U.S. Pat. No. 4,714,382, there is provided a variable truss arrangement that uses two spaced apart barges for placing a deck package on a jacket. The Khachaturian '382 patent uses a variable dimensional truss assembly that is supported by the barge and forms a load transfer interface between the barge and the deck package. Upper and lower connections form attachments between the truss members and the deck package at upper and lower elevational positions on the deck package. The upper connection in the '382 patent is a pinned connection. The variable dimension truss of the '382 patent 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.




The present application relates to improvements to the subject matter of prior U.S. Pat. No. 4,714,382 which is incorporated herein by reference. In

FIG. 2

, the deck package


17


is spaced above the vertical columns


18


of jacket


16


. In order to place the deck package


17


on the jacket


16


, the lifting apparatus


10


of the present invention slowly lowers the deck package


17


to the jacket


16


until lower end portions


19


of the deck package


17


engage and form a connection with the vertical columns


18


of the jacket


16


.




Deck packages


17


are usually constructed of a plurality of welded steel pipe members including at least some of the members that are vertical. In

FIGS. 1 and 2

, a plurality of vertical members


20


are shown, each having a lower end portion


19


that connects with the vertical columns


18


of jacket


16


.




Each of the barges


11


,


12


carries a plurality of booms


21


,


22


. The first barge


11


has four booms


21


in

FIGS. 1 and 2

. Likewise, the second barge


12


has four correspondingly positioned booms


22


. In

FIGS. 1 and 2

, the booms


21


,


22


are equally spaced along the deck


13


or


14


of the corresponding barge


11


or


12


and corresponding to the position and horizontal spacing of the vertical members


20


of package


17


. Further, each of the booms


21


,


22


is supported upon a load spreader platform


23


or


24


. The load spreader platform


23


,


24


can be a combination of static load spreader platforms


23


and movable load spreader platforms


24


. For example, if each barge


11


,


12


has three booms, one platform


24


can be movable. If four booms, two or three platforms


24


can be movable.




The static load spreader platforms


23


are rigidly welded to and connected to the deck


13


of barge


11


, or to the deck


14


of barge


12


. Base plate


27


is rigidly welded to platform


23


. Each load spreader platform


23


,


24


has a pair of spaced apart boom heel pin padeyes


25


,


26


mounted on structural base plate


27


. The base plate


27


can be welded for example to its load spreader platform


23


if a “fixed” platform


23


is desired.




Each load spreader platform


23


,


24


can be constructed of a plurality of perimeter beams


28


and a plurality of internal beams


29


with plate


27


mounted thereon.




The booms


21


,


22


can be constructed of a pair of diagonally extending compression members


30


that form an acute angle. In

FIGS. 1-2

and


8


, each compression member


30


has a pair of spaced apart end caps


31


attached to each of its end portions. This is preferably a removable connection so that compression members


30


of differing lengths can be used for different lifts and the end caps


31


can be reused. Cross bar


30


A spans between connecting members


35


as shown in

FIG. 1

, its ends being connected to members


35


using pinned connections with pins


39


.




Each end cap


31


is preferably comprised of a cylindrical sleeve


32


and a plurality of plate members


33


as shown in FIG.


8


. Each plate member


33


has an opening


34


that receives a pin


39


. Connecting members


35


form a pinned connection with end cap


31


as shown in

FIGS. 1

,


2


, and


8


. The connecting member


35


includes a plurality of plates


36


that are parallel and a second plurality of plates


37


that are perpendicularly positioned with respect to the first plates


36


as shown in FIG.


8


.




Each of the plates


37


has an opening


38


for accepting pin


39


when the connecting member


35


is attached to end cap


31


as shown in

FIGS. 2 and 8

. The connecting member


35


has openings


40


in each of the plates


36


. This enables the plates


36


to be attached with a pinned connection to the heel pin padeyes


25


,


26


as shown in

FIGS. 2 and 8

.




A variable length tensile member


42


extends between heel pin padeyes


25


,


26


and a vertical member


20


of package


17


. As shown in

FIG. 1

, this centers a variable length tensile member


42


and a boom


21


or


22


on each vertical member


20


. As shown in

FIG. 1

, there are four spaced apart vertical members


20


, each having a respective boom


21


or


22


connected thereto and each having a variable length tensile member


42


extending from the barge


11


or


12


to the vertical member


20


.




Each variable length tensile member


42


includes a cable


43


wound upon a pair of sheaves


44


,


45


as shown in

FIGS. 2

,


2


A, and


7


. The sheave


45


is constructed of a pair of plates


46


that are spaced apart so that padeye


50


fits in between the plates


46


. A pinned connection can be formed between padeye


50


and plates


46


of sheave


44


using pin


52


that is inserted through the openings


47


of plate


46


and the opening


51


of padeye


50


.




The padeye


50


is structurally connected (welded, for example) to bridle plate


48


. The bridle plate


48


includes a structural plate body


49


having a pair of plates


53


and


54


at its end portions respectively as shown in FIG.


7


. Each of the plates


53


,


54


has openings


55


through which pin


41


can be inserted when the plates


53


or


54


are connected to respective heel pin padeyes


25


,


26


, as shown in

FIGS. 2 and 7

e.g., with a load cell


89


.




Each boom


21


,


22


provides a lifting end portion


56


that is shown particularly in FIGS.


2


and


3


-


6


. The lifting end portion


56


of each boom


21


,


22


forms a connection with a receptacle


70


that is mounted on vertical member


20


as shown in

FIGS. 1

,


2


,


5


, and


6


. The lifting end portion


56


is constructed of a plurality of spaced apart parallel plates


57


. Each plate


57


has an opening


58


. Gaps


59


,


60


are provided for receiving plates


33


of an end cap


31


. This connection can be seen in

FIGS. 2 and 6

. The lifting end portion


56


provides a pair of inner plates


61


that can be parallel to one another and a pair of outer plates


62


that can form an acute angle.




Roller


63


is positioned in openings formed through the plates


61


as shown in

FIGS. 3 and 4

. Each roller


63


is preferably of an hour glass shape, having a narrow or neck portion


64


and a pair of cylindrically-shaped end portions


65


. Arrow


66


in

FIG. 4

illustrates that the roller


63


can move side to side for adjustment purposes when the booms


21


and


22


are connected to the receptacle


70


and thus to the deck package


17


. In order that roller


63


be allowed to move from side-to-side, there are provided gaps


68


on each side of the roller


63


as shown in FIG.


4


. Stop plates


67


are shaped to limit movement of the roller


63


as it moves from one side to the other as shown by arrow


66


.




Lifting end portion


56


can be connected to the selected boom


21


or


22


with pin connections


69


as shown in FIG.


6


. The openings


58


in plates


57


receive a pin therethrough, that pin also passing through the openings


34


in plates


33


of end cap


31


.




Receptacle


70


is shown more particularly in

FIGS. 2

,


5


, and


6


. Receptacle


70


includes a curved plate


71


that is attached to vertical member


20


of deck package


17


, being structurally affixed thereto by welding, for example.




Receptacle


70


is formed of a plurality of flat plates including a center plate


72


and a pair of smaller side plates


73


,


74


, as shown in FIG.


5


. Recess


75


receives roller


63


upon engagement of lifting end portion


56


and receptacle


70


as shown in FIG.


6


. The neck


64


portion of roller


63


is of a reduced diameter and is shaped to engage inclined edge


76


of plate


72


, then travel upwardly along inclined edge


76


until the neck


64


of roller


63


fully nests in recess


75


of receptacle


70


. This fully engaged position of lifting end portion


56


and receptacle


70


is shown in FIG.


2


.




The receptacle


70


is formed of a pair of vertical sections


77


and


78


, and a transversely extending section


79


. The section


79


can have a flat upper surface that receives reinforcing plate


80


, that can be a horizontally extending plate. In

FIG. 6

, further reinforcement of the attachment of receptacle


70


to deck package


17


is seen. In

FIG. 6

, the horizontal plate


80


is rigidly affixed to the bottom of a horizontal beam


81


by welding, for example. This enables the loads transmitted from lifting end portion


56


to receptacle


70


to be transferred to the deck package


17


at vertical member


20


and at horizontal beam


81


.




In

FIGS. 2 and 6

, arrows


82


illustrate the upward movement of lifting end portion


56


that is used to nests roller


63


in recess


75


of receptacle


70


. In

FIG. 2

, arrow


83


illustrates the upward and downward movement of lifting end portion


56


of booms


21


and


22


to either engage or disengage the boom


21


or


22


from the deck package


17


.




In order to lower the deck package


17


, the cable


43


is unwound using a winch that is carried on the surface of deck


13


or


14


of barge


11


or


12


. This lengthens the distance between heel pin padeyes


25


,


26


and the deck package


17


. By lengthening the distance between the padeyes


25


and


26


of the respective barges


11


and


12


, the variable length tensile member


42


is elongated so that the booms


21


and


22


rotate downwardly about their heel pin padeyes


25


,


26


creating a smaller and smaller angle between the compression members


30


and the barge decks


13


,


14


.




This procedure is reversed in order to lift a deck package


17


upwardly with respect to water surface


15


and jacket


16


. In such a lifting situation, the winch mounted on the deck


13


or


14


of the barges


11


and


12


winds the cable


43


to shorten the distance between sheaves


44


,


45


. This likewise shortens the distance between the heel pin padeyes


25


and


26


on barge


11


with respect to the heel pin padeyes


25


and


26


on barge


12


. The effect is to elevate the lifting end portion


56


and to increase the angle between the compression members


30


and the barge decks


13


,


14


.




In such a lifting situation, tension member


85


can be used in between opposed vertical members


20


as shown in

FIGS. 1 and 2

. Padeyes


87


,


88


can be welded, for example, to vertical member


20


for forming an attachment between tension member


85


and the vertical column


20


. Likewise, a tension member


86


can be placed in between padeye


87


and sheave


45


as shown in FIG.


2


. Thus, a continuous tensile member is formed in between the heel pin padeyes


25


,


26


of barge


11


for each boom


21


, and the corresponding heel pin padeyes


25


,


26


on barge


12


for each of its booms


22


.




During a lifting of a package


17


, hook-up is first accomplished. The booms


21


,


22


are positioned so that the lifting end portion


56


of each boom


21


,


22


is positioned below the corresponding receptacle


70


on package


17


.




An operator or operators then begin hook-up by attaching the cables


43


and sheaves


44


,


45


to the corresponding vertical members


20


, configured as shown in

FIGS. 1

,


2


, and


2


A. The winch W


1


then shortens cable


43


pulling barges


11


,


12


toward package


17


. In such a situation, the lifting end portion


56


will engage vertical member


20


at a position below receptacle


70


. The plates


62


of lifting end portion


56


will engage vertical member


20


and end portion


56


then slides upwardly on the vertical member


20


as cable


43


is shortened until end portion


56


reaches receptacle


70


. Continued shortening of the cable


43


increases the angle of inclination of each boom


21


,


22


relative to the deck


13


,


14


respectively of barges


11


,


12


until lifting end portion


56


registers completely in recess


75


of receptacle


70


. Then, continued shortening of the cable


43


associated with each boom


21


,


22


effects a lifting of the padeyes


17


as the boom


21


,


22


angle of inclination relative to the barge


11


,


12


deck


13


,


14


further increases. The booms


21


,


22


are simultaneously elevated and inclined continuously so that each of the booms


21


,


22


shares a substantially equal part of the load. This can be monitored using load cell link


89


that can be used to monitor the tension between bridle plates


48


and the pinned connection that joins padeyes


25


,


26


and connecting members


35


.




A second winch W


2


can be rigged with a wound line or cable for pivoting each boom


21


,


22


relative to the deck


13


,


14


of barge


11


,


12


respectively (see

FIG. 2A

) such as may be required during an initial positioning of the booms


21


,


22


before a hook-up.




The following table lists the parts numbers and parts descriptions as used herein and in the drawings attached hereto.















PARTS LIST












Part Number




Description









10




lifting apparatus






11




barge






12




barge






13




deck






14




deck






15




water surface






16




jacket






17




deck package






18




vertical column






19




lower end portion






20




vertical member






21




boom






22




boom






23




static load spreader platform






24




movable load spreader platform






25




boom heel pin padeye






26




boom heel pin padeye






27




floating heel pin base plate






28




perimeter beam






29




internal beam






30




compression member









  


30A




cross bar






31




end cap






32




cylindrical sleeve






33




plate






34




opening






35




connecting member






36




plate






37




plate






38




opening






39




pin






40




opening






41




pin






42




variable length tensile member






43




cable






44




sheave






45




sheave






46




plate






47




opening






48




bridle plate






49




body






50




padeye






51




opening






52




pin






53




plate






54




plate






55




opening






56




lifting end portion






57




plate






58




opening






59




gap






60




gap






61




inner plate






62




outer plate






63




roller (hourglass shape)






64




neck






65




cylindrical end






66




arrow






67




stop plate






68




gap






69




pinned connection






70




receptacle






71




curved plate






72




plate






73




plate






74




plate






75




recess






76




inclined surface






77




vertical section






78




vertical section






79




transverse section






80




horizontal plate






81




horizontal beam






82




arrow






83




arrow






84




arrow






85




tension member






86




tension member






87




padeye






88




padeye






89




load cell link






W1




winch






W2




winch














Because many varying and different embodiments may be made within the scope of the inventive concept herein taught, and because many modifications may be made in the embodiments herein detailed in accordance with the descriptive requirement of the law, it is to be understood that the details herein are to be interpreted as illustrative and not in a limiting sense.



Claims
  • 1. A lifting apparatus for lifting a multi-ton package, comprising:a) a pair of floating supports, each defining a base that can support a large multi-ton load; b) a pair of trusses supported respectively by the pair of floating supports and positioned about the periphery of the package during lifting, the trusses forming a load transfer interface between the floating supports 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 floating support and an upper end that can be removably attached to the package; d) each boom having a free end with a lifting end portion; e) a receptacle attached to the package that receives the lifting free end portion; f) wherein the lifting end portion engages the receptacle as the boom angle of inclination is gradually increased; and g) means for raising and lowering the combination of the truss and the supported package.
  • 2. The lifting apparatus of claim 1 wherein each truss is a variable dimension truss means that includes at least one lifting boom and at least one member of variable length.
  • 3. The lifting apparatus of claim 2 wherein the floating supports are barges and there are at least three lifting booms on each barge, and the barges have horizontal load spreader surfaces for holding the booms.
  • 4. The lifting apparatus of claim 2 wherein the trusses include opposing truss members that are each pinned to a different barge and which are angularly disposed with respect to each other during use, wherein each boom includes an elongated compression member and end caps that form a detachable interface between the compression member and each barge.
  • 5. The lifting apparatus of claim 1 wherein each truss includes at least one flexible cable.
  • 6. The lifting apparatus of claim 1 wherein a portion of the lifting end portion slides side to side for effecting adjustment during connection of a lifting end portion to its receptacle.
  • 7. The lifting apparatus of claim 6 wherein each truss includes a wound cable extending between a pair of sheaves, wherein the distance between the sheaves can be lengthened or shortened.
  • 8. The lifting apparatus of claim 1 wherein each lifting boom is an “A” frame shaped boom that comprises a pair of longitudinal boom members that form an acute angle, a pair of lifting end portions that form a detachable interface between each longitudinal boom member and a floating support, the free end portion having a structural member and a pair of end caps that form a detachable connection between the longitudinal boom members and the lifting end portion.
  • 9. The lifting apparatus of claim 3 wherein the variable length member includes multiple cable assemblies spaced along the upper deck surface of each barge.
  • 10. A method for the offshore lifting of a multi-ton package comprising the steps of:a) transporting a lifting assembly to a desired site of the package; 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 multiple chords, including a generally 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” all 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 floating supports; and f) lifting the package upon by changing the length of the horizontal chord of the lifting assembly.
  • 11. The method of claim 10, further comprising the step of lowering the package by lengthening the horizontal chord.
  • 12. The method of claim 10, wherein in step “d”, the lifting end portion includes a roller that is laterally adjusted.
  • 13. The method of claim 11, wherein the horizontal chord includes a winch that is wound with a lift cable, and winding or unwinding the winch in order to change the length of the lift cable.
  • 14. The method of claim 10, wherein there are two opposed supports that are floating barges.
  • 15. The method of claim 10, wherein one portion of the lifting assembly includes a plurality of compression carrying diagonally extending lift booms, each with opposing end portions and a plurality of end caps that removably attach to the end portions.
  • 16. The method of claim 15, wherein each floating support has a winch structurally mounted thereon and a lower connection formed with the package includes a flexible cable wound upon sheaves and further comprising extending the cable between the winch and the package.
  • 17. The method of claim 16, wherein the lifting assembly includes a plurality of non-extensible diagonally extending lift booms, each removably connecting at its ends to an end cap.
  • 18. A method for the offshore lifting a multi-ton package, comprising the steps of:a) transporting a lifting assembly to a desired site having the package; b) attaching the lifting assembly to the package at multiple positions that are at least on generally opposite sides of the package; c) wherein the lifting assembly includes opposed floating supports having decks and diagonally extending lifting booms thereon connected at their upper ends with a lifting end portion to a receptacle on the package; d) structurally supporting each of the lifting booms at the lower end portion thereof with one of the floating supports, each boom being pivotally attached to its floating support; 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 floating support; 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.
  • 19. A lifting apparatus for lifting a multi-ton package, comprising: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 are positioned about the periphery of the package during lifting for forming a load transfer interface 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 package; d) each boom having a free end with a lifting end portion; e) a receptacle attached to the package that receives the lifting free end portion; f) wherein the lifting end portion engages the receptacle as the boom angle of inclination is gradually increased; and g) a power unit associated with each boom for raising and lowering the combination of the truss and the supported package.
  • 20. A lifting apparatus for lifting a multi-ton package comprising: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 are positioned during lifting about the periphery of the package for forming a load transfer interface 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 package; d) each boom having a free end with a lifting end portion; e) a receptacle attached to the package that receives the lifting free end portion of the boom; f) wherein the lifting end portion engages the receptacle as the boom angle of inclination is gradually increased, and g) a power unit for raising and lowering the combination of the truss and the supported package.
CROSS-REFERENCE TO RELATED APPLICATIONS

This is a continuation of U.S. patent application Ser. No. 08/915,617, filed Aug. 21, 1997, U.S. Pat. No. 6,149,350, which is a continuation-in-part of U.S. patent application Ser. No. 08/709,014, filed Sep. 6, 1996, U.S. Pat. No. 5,800,093, which is a continuation-in-part of U.S. patent application Ser. No. 08/615,838, filed Mar. 14, 1996, U.S. Pat. No. 5,662,434, which is a continuation-in-part of U.S. patent application Ser. No. 08/501,717, filed Jul. 12, 1995, now U.S. Pat. No. 5,607,260, which is a continuation-in-part of U.S. application Ser. No. 08/404,421 filed Mar. 15, 1995, now U.S. Pat. No. 5,609,441, each of which is hereby incorporated herein by reference.

US Referenced Citations (10)
Number Name Date Kind
2598088 Wilson May 1952 A
3977346 Natvig et al. Aug 1976 A
4242011 Karsan et al. Dec 1980 A
4249618 Lamy Feb 1981 A
4252468 Blight Feb 1981 A
4252469 Blight et al. Feb 1981 A
4714382 Khachaturian Dec 1987 A
4744697 Coppens May 1988 A
5037241 Vaughn et al. Aug 1991 A
6149350 Khachaturian Nov 2000 A
Continuations (1)
Number Date Country
Parent 08/915617 Aug 1997 US
Child 09/718304 US
Continuation in Parts (4)
Number Date Country
Parent 08/709014 Sep 1996 US
Child 08/915617 US
Parent 08/615838 Mar 1996 US
Child 08/709014 US
Parent 08/501717 Jul 1995 US
Child 08/615838 US
Parent 08/404421 Mar 1995 US
Child 08/501717 US