A TEMPORARY WORKING PLATFORM, A TRANSPORT SYSTEM, A VESSEL, AND A METHOD

Abstract

A temporary working platform for removable attachment to a column of an offshore structure. The platform comprises a frame for carrying a working structure such as a working surface. Further, the platform comprises a mounting mechanism for releasably mounting the working platform to said column, from a side of the column. The mounting mechanism may include a clamping mechanism supporting the frame. The clamping mechanism may be arranged for at least partially surrounding a column of an offshore structure and for releasably clamping said column.

Claims

1. A temporary working platform for removable attachment to a column of an offshore structure, comprising a frame for carrying a working structure, in particular a working surface, and a mounting mechanism for releasably mounting the working platform to said column, from a side of the column.

2. The temporary working platform according to claim 1, wherein the mounting mechanism includes at least one of a unit for disposing a non-permanent adhesive, an electromagnetic device and a clamping mechanism.

3. The temporary working platform according to claim 2, wherein the clamping mechanism supports the frame and is arranged for at least partially surrounding the column and for releasably clamping said column.

4. The temporary working platform according to claim 3, wherein the clamping mechanism includes a pair of clamping jaws having respective free ends, the jaws being mutually removable between a releasing state wherein the jaw free ends are relatively remote from each other and a clamping state wherein the jaw free ends are relatively close to each other.

5. The temporary working platform according to claim 4, wherein the pair of clamping jaws are pivotably mounted to each other such that the clamping jaws are pivotable between the releasing state and the clamping state.

6. The temporary working platform according to claim 3, further comprising an actuator for controllably driving the clamping mechanism.

7. The temporary working platform according to claim 3, wherein the frame includes a pair of frame elements, each frame element being supported by a corresponding clamping jaw.

8. The temporary working platform according to claim 7, wherein the clamping jaws and/or the frame elements are mainly shaped as curved portions for at least partially surrounding the column of an offshore structure.

9. The temporary working platform according to claim 4, wherein the clamping jaws include an elastic layer mounted on a clamping side of said clamping jaws.

10. The temporary working platform according to claim 7, wherein the clamping jaws and/or the frame elements are located at mutually opposite locations.

11. The temporary working platform according to claim 1, wherein the working structure includes a grating or another working surface, and/or a working device such as a hoist.

12. The temporary working platform according to claim 1, further comprising a first coupling element for releasable coupling to a second coupling element mounted on a transport system transporting the platform to and from the column of the offshore structure.

13. The temporary working platform according to claim 12, wherein the transport system is a telescopic gangway.

14. The temporary working platform according to claim 12, wherein the first or second coupling element includes a guiding structure for guiding the first and second coupling elements towards each other.

15. The temporary working platform according to claim 12, further comprising a locking element for locking the first coupling element to the second coupling element.

16. The temporary working platform according to claim 2, wherein the clamping mechanism clamps a column of an offshore construction.

17. A transport system, in particular a telescopic gangway, comprising a second coupling element for releasable coupling to a first coupling element of the temporary working platform according to claim 12.

18. The transport system according to claim 17, wherein the second coupling element is mounted to a free end or tip of the transport system.

19. The transport system according to claim 17, coupled to the temporary working platform.

20. A vessel, comprising a transport system, such as a telescopic gangway, according to claim 17.

21. A telescopic gangway and a temporary working platform, wherein the telescopic gangway comprises first and second gangway parts which are telescopable relative to each other in a longitudinal direction, as well as a primary coupling element for removably coupling the telescopic gangway to the temporary working platform, and wherein the temporary working platform comprises a secondary coupling element for removably coupling the temporary working platform to the telescopic gangway, as well as an actuated clamping mechanism suitable for removably attaching the working platform to a column of an offshore construction by at least partially surrounding said column with said actuated clamping mechanism.

22. A method of handling a temporary working platform according to claim 2.

23. The method according to claim 22, comprising a step of controllably driving the clamping mechanism to a clamping state wherein the clamping mechanism clamps a column of an offshore construction.

24. The method according to claim 23, further comprising a step of decoupling the temporary working platform from a transport system, after the step of controllably driving the clamping mechanism to the clamping state.

25. The method according to claim 22, comprising a step of coupling the temporary working platform to a transport system, the temporary working platform being removably attached to a column of an offshore construction.

26. The method according to claim 25, further comprising a step of driving the clamping mechanism to a releasing state wherein the clamping mechanism releases the column of the offshore construction, after the coupling step.

Description

[0022] The invention will be further elucidated on the basis of exemplary embodiments which are represented in the drawings. The exemplary embodiments are given by way of non-limitative illustration of the invention. In the drawings:

[0023] FIG. 1 shows a schematic perspective view of a temporary working platform according to the invention;

[0024] FIG. 2 shows a schematic top view of the temporary working platform shown in FIG. 1;

[0025] FIG. 3 shows a schematic side view of the temporary working platform shown in FIG. 1;

[0026] FIG. 4 shows a schematic front view of the temporary working platform shown in FIG. 1;

[0027] FIG. 5 shows a vessel comprising a telescopic gangway coupled to a temporary working platform according to the invention,

[0028] FIG. 6 shows the vessel depicted in FIG. 5, wherein the temporary working platform is attached to a column of an offshore construction,

[0029] FIG. 7 shows the vessel depicted in FIG. 5, wherein the temporary working platform has been decoupled,

[0030] FIG. 8 shows the vessel depicted in FIG. 5, wherein the telescopic gangway is coupling to the temporary working platform,

[0031] FIG. 9 shows the vessel depicted in FIG. 5, wherein the temporary working platform has been released from the column of an offshore construction,

[0032] FIG. 10 shows a flow diagram of a method according to the invention,

[0033] FIG. 11A shows a schematic top view of another temporary working platform according to the invention, in a first state,

[0034] FIG. 11B shows a schematic top view of the temporary working platform of FIG. 11A in a second state,

[0035] FIG. 12A shows a schematic side view of the temporary working platform of FIG. 11A in the first state,

[0036] FIG. 12B shows a schematic side view of the temporary working platform of FIG. 11A in the second state,

[0037] FIG. 13A shows a schematic top view of yet another temporary working platform according to the invention, in a first state, and

[0038] FIG. 13B shows a schematic top view of the temporary working platform of FIG. 13B in a second state.

[0039] In the figures identical or corresponding parts are represented with the same reference numerals. The drawings are only schematic representations of embodiments of the invention, which are given by manner of non-limited examples.

[0040] FIG. 1 shows a schematic perspective view of a temporary working platform 1 according to the invention. The temporary working platform 1 includes a frame 2 and a mounting mechanism for releasably mounting the working platform to a column 20 of an offshore structure, from a side of the column 20. The mounting mechanism is provided, in the shown embodiment, with a clamping mechanism 3 supporting the frame. In use, the temporary working platform 1 can be removably attached to said column 20, using the clamping mechanism 3. The offshore structure is e.g. a drilling rig, drilling platform or offshore windmill, the column also referred to as jacket leg.

[0041] The frame 2 of the temporary working platform 1 is arranged for carrying a working structure such as a working surface 4 or another working structure such as a hoisting device. The working surface 4 may be implemented as a grating or another working surface such as a supporting plate.

[0042] The clamping mechanism 3 is arranged for at least partially surrounding a column 20 of an offshore structure and for releasably clamping said column 20.

[0043] In the shown embodiment, the clamping mechanism 3 includes a pair of clamping jaws 3a,b that are pivotably mounted to each other such that the clamping jaws 3a,b are pivotable with respect to a pivoting axis PA between a releasing state and a clamping state. Each of the clamping jaws 3a,b has a free end 5a,b, respectively, also referred to as distal free ends 5a,b. In the releasing state, the jaw free ends 5a,b are relatively remote from each other, while, in the clamping state, the jaw free ends 5a,b are relatively close to each other. Further, the clamping mechanism 3 may include a locking element for locking the jaw free ends 5a,b to each other, in the clamping state so as to counteract that the clamping jaws 3a,b move unintentionally away from each other. In the releasing state, the platform 1 can be moved towards or from the column 20 of the offshore structure. In the clamping state, the platform 1 is releasably attached to said column 20.

[0044] The temporary working platform 1 further includes an actuator 6 for controllably driving the clamping mechanism 2. The actuator 6 may include a motor 6″ such as a hydraulic or an electric motor, as well as a driving element 6′ driven by said motor 6″ for moving a first clamping jaw 3a relative to a second clamping jaw 3b such that the clamping mechanism opens from or closes towards the clamping state, like a pair of pincers. The actuator 6 may be operated by a control unit having an interface for manual or remote interaction by a user of the actuator 6.

[0045] FIG. 2 shows a schematic top view of the temporary working platform 1 shown in FIG. 1. Here, the clamping mechanism 3 is shown in both the clamping state CS and the releasing state RS.

[0046] In the shown embodiment, the driving element 6′ pivots the first clamping jaw 3a relative to the second clamping jaw 3b by exerting a driving force to the first clamping jaw 3a. Here, the first clamping jaw 3a is formed as a lever rotating around the pivoting axis PA having a proximal end 3a′ to which the driving element 6′ is connected for receiving said driving force. During movement, one of the jaw free distal ends 5a,b or both jaw free distal ends 5a,b move along a displacement path DPa, DPb that is mainly circular. In the shown embodiment, the jaw free distal ends 5a,b move in a symmetric way relative to a plane of symmetry PS, e.g. for balancing reasons.

[0047] Generally, the actuator may be provided in or on the platform 1 or on another structure such as a telescopic gangway or another transport system coupled to the temporary working platform 1.

[0048] Further, the clamping mechanism 3 may be implemented as another structure wherein the clamping jaws 3a,b controllably move towards and from each other, e.g. following a non-circular curved or straight path, contrary to the circular displacement path DPa, DPb. Also, the clamping mechanism may include more than two clamping jaws or clamping elements for releasably clamping a column 20 of an offshore construction.

[0049] The frame 2 includes a pair of frame elements 2a,b wherein each frame element 2a,b is supported by a corresponding clamping jaw 2a,b. Then, a wide angle range access to the column 20 is provided, e.g. at least 180 degrees or more. Further, a number of workers may work on the platform, up to a safety load of e.g. 500 kg. In another embodiment, the frame 2 includes more than two frame elements, e.g. four or six frame elements. Further, the frame 2 may include a single frame element, e.g. supported by one of the clamping jaws 3a,b.

[0050] In the shown embodiment, the clamping jaws 3 and the frame elements 2 are mainly shaped as curved portions for at least partially surrounding the column 20 of an offshore structure. Preferably, the clamping jaws and/or the frame element 2 are mainly shaped as annular portion segments around a common axis of symmetry AS mainly coinciding with a longitudinal axis of the column 20, in the clamped state of the platform 1. A radial inner contour 7 of the clamping jaws 3 and/or the frame elements 2 may have a constant curvature of radiation that may mainly match with the curvature of the exterior wall of the column 20.

[0051] The clamping jaws 3 may be provided with an elastic layer mounted on a clamping side of said jaws, such as the above mentioned radial inner contour 7, thereby reducing a chance that permanent damage may occur at the column 20 to be clamped. Further, the clamping jaws 3 may be provided with clamping shoes, at the radial inner contour 7.

[0052] The frame elements 2 and/or the clamping jaws are located at mutually opposite locations, symmetric with respect to the plane of symmetry, facing each other and clamping the column 20 between the opposite clamping jaws 3, as a pair of pincers.

[0053] FIG. 3 shows a schematic side view of the temporary working platform 1 shown in FIG. 1.

[0054] FIG. 4 shows a schematic front view of the temporary working platform 1 shown in FIG. 1.

[0055] The shown temporary working platform 1 is coupled to a telescopic gangway 72 described in more detail below. In the shown embodiment, the temporary working platform 1 has a first coupling element 8, e.g. mounted on the frame 2 or clamping mechanism 3, the first coupling element 8 being coupled to a second coupling element 9 mounted on the free end or tip 73 of the telescopic gangway 72. In the coupled state, the telescopic gangway 72 can transport the platform 1 to and from the column 20 of the offshore structure.

[0056] It is noted that the second coupling element 8, serving as a launch mechanism, may be mounted to a different gangway or to another transport system such as a crane.

[0057] Advantageously, the first coupling element 8 is provided with a guiding structure for guiding the first and second coupling elements 8, 9 towards each other. The guiding structure may include a self centering or self aligning structure such as tapered or V-shaped guiding plates for aligning the second coupling element 9 in a horizontal and/or vertical direction, during a positioning/coupling process. Accordingly, the second coupling element 9 may include a corresponding wedge-shaped insertion element or tapered pin module to be guided and/or received by the guiding structure of the first coupling element 8. In a horizontal plane, the guiding structure may allow freedom for alignment and in a vertical plane for landing under different angles. Further, the guiding structure provides a secure locking position of the second coupling element. Alternatively, the second coupling element 9 may be provided with a guiding structure for guiding the first coupling element 8.

[0058] Further, the platform 1 includes a locking element 10 for locking the first coupling element 8 to the second coupling element 9.

[0059] FIG. 5 shows a vessel 60 comprising a telescopic gangway 72 coupled to a temporary working platform 1 according to the invention.

[0060] Generally, a motion compensated gangway 70 comprises a movable transition deck 71 and a telescopic gangway 72 connected to the transition deck 71. The telescopic gangway 72 has a tip 73 that may be held, during operation of the motion compensated gangway 70, in close proximity of an object such as an offshore construction 21 to or from which a load or a person has to be transferred. The motion compensation system 70 may use actuators, e.g. hydraulic pistons 74, to compensate for relative motion between the vessel 60 on which the motion compensated gangway 70 is mounted and the object to or from which the load/person can be transferred. Said relative motion may for example result from waves or rolling, pitching, and/or yawing motion of a vessel or boat 60 floating on the water 61.

[0061] The telescopic gangway 72 may comprise a first and second gangway part, for example a telescoping and main boom, which are telescopable with respect to each other in a longitudinal direction to adjust a longitudinal length of the telescopic gangway. Within the context of this application the term telescopable is meant to be construed as being movable, such as being able to move in and out of each other and/or with respect to each other along said longitudinal direction.

[0062] The first and second gangway part may each have a walkboard or walkplank to facilitate transfer of persons and/or goods.

[0063] Motion compensated gangways per se, such as for compensating for vessel motions when transferring personnel and/or loads are known in the art. For example from the Ampelmann® system as disclosed in general in NL1027103, or systems disclosed in WO2012/138227 and WO2013/10564.

[0064] Patent publication NL1027103 discloses a vessel with a Stewart type construction for compensating motions of a ship. The construction comprises a transition deck, borne on six hydraulic cylinders, and motion sensors. During use, with the aid of the sensors, the motions of the vessel are measured. With the aid of these measurements, the orientation and/or position of the cylinders is driven continuously so that the transition deck remains approximately stationary relative to the fixed world. A luffing gangway is connected to the transition deck. In this manner, motions of the vessel are compensated and for instance people or loads can be transferred from the vessel onto a stationary offshore construction, or vice versa.

[0065] In FIG. 5, the telescopic gangway 72 is coupled to the temporary working platform 1 using the coupling elements 8, 9 described above, for moving or deploying the platform to a column 20 of the offshore construction 21.

[0066] FIG. 6 shows the vessel 60 depicted in FIG. 5, wherein the temporary working platform 1 is releasably attached to a column or pillar 20 of an offshore construction 21. Here, the clamping mechanism 3, also referred to as actuated clamping mechanism, has been actuated to move to the clamping state for clampingly attachment or clamp on to the column 21. Preferably, the telescopic gangway 72 pushes the platform 1 against the column 20 to temporarily fix a desired position of the platform 1 relative to the column 20 during closure of the clamping mechanism 3. Also, persons and/or goods can be transferred to the platform 1, e.g. for maintenance activities to the column 20.

[0067] Generally, the actuated clamping mechanism is suitable for removably attaching the working platform to a column of an offshore construction by at least partially surrounding said column with said actuated clamping mechanism.

[0068] FIG. 7 shows the vessel 60 depicted in FIG. 5, wherein the temporary working platform 1 has been decoupled or disconnected. Here, the telescopic gangway 72 is moving away from the temporary working platform 1 attached to the column 20.

[0069] FIG. 8 shows the vessel 60 depicted in FIG. 5, wherein the telescopic gangway 72 is landing for coupling to the temporary working platform 1, e.g. for potential people and/or goods transfer.

[0070] FIG. 9 shows the vessel 60 depicted in FIG. 5, wherein the temporary working platform 1 has been released from the column 20 of an offshore construction 21. Here, the clamping mechanism 3 has been brought into the releasing state for retrieval of the platform 1 that can be re-used at another location of the column 20, to another column 20 or for further applications.

[0071] FIG. 10 shows a flow chart of a method of handling a temporary working platform according to the invention. Particularly, the method includes a step of handling 100 a temporary working platform 1 as described above.

[0072] The method may include a step of controllably driving the clamping mechanism 3 to a clamping state wherein the clamping mechanism 3 clamps a column 20 of an offshore construction 21.

[0073] The method may also include a step of decoupling the temporary working platform 1 from a transport system such as a telescopic gangway 72, after the step of controllably driving the clamping mechanism to the clamping state

[0074] Further, the method may include a step of coupling the temporary working platform 1 to a transport system such as a telescopic gangway 72, the temporary working platform 1 being removably attached to a column of an offshore construction. As a next step, the method may include a step of driving the clamping mechanism 3 to a releasing state wherein the clamping mechanism 3 releases the column 20 of the offshore construction 21.

[0075] FIG. 11A shows a schematic top view of another temporary working platform 200 according to the invention, in a first state wherein the platform 20 is not mounted to the column 20 of the offshore structure. FIG. 11B shows a schematic top view of the temporary working platform 200 of FIG. 11A in a second state wherein the platform 20 is mounted to the column 20. Here, the clamping mechanism includes a multiple number of wedges 201, 202, 203, 204 oriented such that their tapered end 207 points upwardly. Further, the wedges 201-204 are located on a contour 208 for at least partly surrounding the column 20. Preferably, at least one wedge 201 of the multiple number of wedges 201-204 is movable along a moving direction M, between a first position P1, shown in FIG. 11A, enabling the column 20 to be received into said contour 208, and a second position P2, shown in FIG. 11B, wherein the column 20 is actually received into said contour 208.

[0076] The clamping mechanism further includes a locking ring, in the shown embodiment including two mainly semi-annular elements 205, 206 that are pivotable to each other between an open state for receiving the column 20, as shown in FIG. 11A and a closed state for locking the column 20, as shown in FIG. 11B.

[0077] FIG. 12A shows a schematic side view of the temporary working platform 200 of FIG. 11A in the first state, corresponding with FIG. 11A.

[0078] During a process of mounting the temporary working platform 200 to the column 20, the at least one wedge 201 is brought in the first position P1, and the semi-annular elements 205, 206 are brought in the open state, as shown in FIG. 11A. Then, the column 20 is received into the contour 208 and in the semi-annular elements 205, 206. Subsequently, the at least one wedge 201 is brought into the second position P2, and the semi-annular elements 205, 206 are brought into the closed state, as shown in FIG. 11B, thereby locking the column 20 in a mainly horizontal plane.

[0079] As a next step, the semi-annular elements 205, 206 move downwardly along a mainly downward direction D, thereby pressing the wedges 201-204 radially inwardly towards the column 20 so as to clamp the platform 200 to the column 20, the locking ring blocking any movement of the wedges 201-204 in a radial, circumferential or downward direction D.

[0080] FIG. 12B shows a schematic side view of the temporary working platform 200 of FIG. 11A in the second state, corresponding to FIG. 11B, after moving the semi-annular elements 205, 206 downwardly.

[0081] The temporary working platform 200 can be removed from the column 20 by performing the above steps in a reverse order.

[0082] Various variations are possible. As an example, more or less than four wedges can be applied. Further, in addition or alternative to the wedges, pressure shoes can be applied pressurizable against the column from respective circumferential positions. Also, a clamping belt can be applied releasably enclosing the column, from a side of the column 20.

[0083] FIG. 13A shows a schematic top view of yet another temporary working platform 200 according to the invention, in a first state. Further, FIG. 13B shows a schematic top view of the temporary working platform 200 of FIG. 13B in a second state. Here, the clamping mechanism of the platform 200 includes two mainly semi-annular clamping elements 211, 212 that are mutually rotatable between the first state wherein they mainly overlap, and the second state wherein they do not overlap or only for minor portion. In the first state, the clamping elements 211, 212 may receive the column 20, while in the second state, said clamping elements 211, 212 lock the column 20 in a mainly horizontal plane. Any movement in a vertical direction may be blocked by an additional mechanism, such as pressurizing shoes described above. Further, a downward movement of the semi-annular clamping elements 211, 212 may be blocked, in the second state, if the column 20 has a conical shape, tapered upwardly.

[0084] The mounting mechanism of the temporary working platform may further include other mounting structures, optionally instead of a clamping mechanism, such as a unit for disposing a non-permanent adhesive between the column and the platform, and/or an electromagnetic device for magnetic coupling with a column having magnetizable material such as steel.

[0085] According to an aspect of the invention a telescopic gangway and a temporary working platform are provided, wherein the telescopic gangway comprises first and second gangway parts which are telescopable relative to each other in a longitudinal direction, as well as a primary coupling element for removably coupling the telescopic gangway to the temporary working platform, and wherein the temporary working platform comprises a secondary coupling element for removably coupling the temporary working platform to the telescopic gangway, as well as an actuated clamping mechanism suitable for removably attaching the working platform to a column of an offshore construction by at least partially surrounding said column with said actuated clamping mechanism. Here, the primary coupling element corresponds with the second coupling element described above arranged for removably coupling the telescopic gangway to the temporary working platform, while the secondary coupling element corresponds with the first coupling element described above for removably coupling the temporary working platform to the telescopic gangway.

[0086] It will be clear to the skilled person that the invention is not limited to the exemplary embodiment represented here. Many variations are possible.

[0087] Such variations shall be clear to the skilled person and are considered to fall within the scope of the invention as defined in the appended claims.

LIST OF REFERENCE SIGNS

[0088] AS Axis of symmetry [0089] PA Pivoting Axis [0090] PS Plane of symmetry [0091] CS Clamping State [0092] RS Releasing State [0093] DPa Displacement Path a [0094] DPb Displacement Path b [0095] 1. Temporary Working Platform [0096] 2. Frame, frame elements [0097] 3. Clamping mechanism, clamping jaws [0098] 4. Working surface [0099] 5. Free end of clamping jaws [0100] 6. Actuator [0101] 7. Radial inner contour of clamping jaw [0102] 8. First coupling element [0103] 9. Second coupling element [0104] 10. Locking element [0105] 20. Column [0106] 21. Offshore construction [0107] 60. Vessel [0108] 61. Water [0109] 70. Motion compensated gangway [0110] 71. Movable Transition Deck [0111] 72. Telescopic gangway [0112] 73. Tip [0113] 74. Hydraulic piston [0114] 200. Temporary Working Platform [0115] 201-204. Wedge [0116] 205-206. Semi-annular element [0117] 207. Wedge tapered end [0118] 208. Contour [0119] 211-212. Semi-annular clamping element