Load bearing apparatus and method

Abstract

A load-bearing apparatus (100) comprises a winch apparatus (110), and a load-bearing spoolable medium (120) for connecting to a load, the load-bearing spoolable medium comprising a plurality of load-bearing elements (121-123); wherein at least a portion of the load-bearing spoolable medium is spooled about the winch apparatus. The provision of multiple load-bearing elements may help reduce the diameter appropriate for the winch apparatus, while maintaining the necessary load bearing capacity for supporting, paying in and/or paying out the load. The load-bearing apparatus may comprise a tension control apparatus (151-153) for controlling, applying and/or adjusting the tension of the load-bearing spoolable medium.

Claims

1. A load-bearing apparatus comprising: a detensioning winch apparatus defining an outboard side and an inboard side; and a load-bearing spoolable medium for connecting to a load on the outboard side of the detensioning winch apparatus, the load-bearing spoolable medium comprising a plurality of load-bearing elements, being spooled for at least one turn about the detensioning winch apparatus, and defining an outboard portion extending on the outboard side of the detensioning winch apparatus and an inboard portion extending on the inboard side of the detensioning winch apparatus; and a tension control apparatus for individually and variably controlling the tension of each of the plurality of load-bearing elements; wherein the load-bearing elements are arranged side-by-side on a contact surface of the detensioning winch apparatus; and wherein the detensioning winch apparatus reduces tension within the load-bearing spoolable medium from the outboard portion to the inboard portion.

2. The load-bearing apparatus according to claim 1, wherein the plurality of load-bearing elements comprises 2 to 5 load-bearing elements.

3. The load-bearing apparatus according to claim 2, wherein the plurality of load-bearing elements comprises 3 load-bearing elements.

4. The load-bearing apparatus according to claim 1, further comprising a plurality of tension-measuring devices, each capable of measuring the tension of a respective load-bearing element.

5. The load-bearing apparatus according to claim 4, wherein at least one actuator and/or tension control device is activated and/or actuated in response to a measurement made by a/the tension-measuring device(s).

6. The load-bearing apparatus according to claim 1, wherein the tension control apparatus is provided on an inboard side of the detensioning winch apparatus, and is arranged to control, apply, and/or adjust the tension of an inboard portion of the plurality of load-bearing elements.

7. The load-bearing apparatus according to claim 6, wherein the tension control apparatus is arranged to control, apply, and/or adjust the tension of the inboard portion of the plurality of load-bearing elements to maintain or apply substantially equal tensions between respective outboard portions of the plurality of load-bearing elements.

8. The load-bearing apparatus according to claim 1, wherein the contact surface of the detensioning winch apparatus engages at least a portion of each of the plurality of load-bearing elements.

9. The load-bearing apparatus according to claim 1, wherein the detensioning winch apparatus comprises or defines a detensioning device.

10. The load-bearing apparatus according to claim 1, wherein one or more load-bearing elements comprise an elongate load-bearing element.

11. The load-bearing apparatus according to claim 1, wherein one or more load-bearing elements comprise a synthetic fibre rope.

12. The load-bearing apparatus according to claim 1, wherein the plurality of load-bearing elements comprises a plurality of separate load-bearing elements.

13. The load-bearing apparatus according to claim 1, wherein the load-bearing elements are arranged on the contact surface of the detensioning winch apparatus in a plane substantially parallel to an axis of rotation of the detensioning winch apparatus, and/or substantially tangential to the contact surface of the detensioning winch apparatus.

14. The load-bearing apparatus according to claim 1, wherein the load-bearing elements are arranged in sequential order around or about the detensioning winch apparatus.

15. The load-bearing apparatus according to claim 1, wherein a weight of the load is distributed amongst the plurality of load-bearing elements.

16. The load-bearing apparatus according to claim 1, wherein a diameter of each of the plurality of load-bearing elements is substantially identical.

17. The load-bearing apparatus according to claim 1, wherein a contact surface of the detensioning winch apparatus is substantially flat or grooved.

18. The load-bearing apparatus according to claim 1, wherein a contact surface of the detensioning winch apparatus is substantially continuous or interrupted.

19. The load-bearing apparatus according to claim 1, wherein the tension control apparatus comprises a plurality of tension control devices, each capable of controlling, applying and/or adjusting the tension of a respective load-bearing element.

20. The load-bearing apparatus according to claim 1, wherein the tension control apparatus is arranged to maintain a difference in tension between the load-bearing elements at or below a predetermined level.

21. The load-bearing apparatus according to claim 1, comprising a storage apparatus for storing the load-bearing spoolable medium on the inboard side of the detensioning winch apparatus.

22. A method for bearing a load, comprising: spooling a load-bearing spoolable medium around a detensioning winch apparatus for at least one turn, wherein the load-bearing spoolable medium comprises a plurality of load-bearing elements arranged side-by-side on a contact surface of the detensioning winch apparatus, wherein the load-bearing spoolable medium defines an outboard portion extending on an outboard side of the detensioning winch apparatus and an inboard portion on an inboard side of the detensioning winch apparatus; and connecting a load to the load-bearing spoolable medium on the outboard side of the detensioning winch apparatus; and individually and variably controlling the tension of each of the plurality of load-bearing elements; wherein the detensioning winch apparatus reduces tension within the load-bearing spoolable medium from the outboard portion to the inboard portion.

23. The method according to claim 22, comprising controlling paying out and/or paying in of the plurality of load-bearing elements.

24. The method according to claim 22, comprising controlling applying and/or adjusting the tension of the plurality of load-bearing elements on the inboard side of the detensioning winch apparatus and/or on the inboard portion of the load-bearing elements.

25. The method according to claim 22, comprising measuring the tension of each load-bearing element.

26. The method according to claim 22, comprising controlling, applying and/or adjusting the tension of one or more load-bearing elements in response to measuring the tension of one or more load-bearing element.

27. The method according to claim 22, comprising providing feedback following measurement of the tension of one or more load-bearing element.

28. The method according to claim 22, comprising operating in a closed-loop control system.

29. The method according to claim 22, comprising automatically controlling, applying and/or adjusting the tension of one or more load-bearing element in response to measuring the tension of one or more load-bearing element.

30. The method according to claim 22, comprising manually controlling, applying and/or adjusting the tension of one or more load-bearing element in response to measuring the tension of one or more load-bearing element.

31. A load-bearing apparatus comprising: a winch apparatus; and a load-bearing spoolable medium for connecting to a load, the load-bearing spoolable medium comprising a plurality of load-bearing elements; a tension control apparatus for controlling the tension of each of the plurality of load-bearing elements, the tension control apparatus comprising a plurality of tension control devices, each capable of controlling the tension of a respective load-bearing element and at least one actuator for actuating one or more tension control devices; wherein at least a portion of the load-bearing spoolable medium is spooled about the winch apparatus, wherein the load-bearing elements are arranged side-by-side on a contact surface of the winch apparatus.

Description

BRIEF DESCRIPTION OF DRAWINGS

(1) Embodiments of the present invention will now be described by way of example only, with reference to the accompanying drawings, in which:

(2) FIG. 1 is a schematic side view representation of a load-bearing apparatus according to a first embodiment of the present invention;

(3) FIG. 2 is a top view of a load-bearing apparatus according to a second embodiment of the present invention;

(4) FIG. 3 is a cross-sectional view of a load-bearing apparatus according to a third embodiment of the present invention;

(5) FIG. 4 is a cross-sectional view of a load-bearing apparatus according to a fourth embodiment of the present invention;

(6) FIG. 5 is a side view of a tension control apparatus according to a fifth embodiment of the present invention;

(7) FIG. 6 is a side view of a tension control apparatus according to a sixth embodiment of the present invention.

DETAILED DESCRIPTION OF DRAWINGS

(8) FIG. 1 shows a schematic side view representation of a load-bearing apparatus 100 according to a first embodiment of the present invention.

(9) The exemplary load-bearing apparatus 100 of FIG. 1 reflects an offshore application such as an off-shore platform or vessel. However, the load-bearing apparatus 100 may equally find use in other applications, for example cranes such as off-shore on on-land cranes; towing systems; weight, counterweight, or cantilever devices; tension controlling devices; structural applications such as station keeping or any other structural applications requiring dynamic positioning and/or tensioning of a structure; or the like.

(10) The load-bearing apparatus 100 comprises a winch apparatus 110.

(11) The load-bearing apparatus 100 also comprises a load-bearing spoolable medium 120 for connecting to a load 130.

(12) The load-bearing spoolable medium 120 is shown in schematic form in FIGS. 1 and 2 for ease of reading. The load-bearing spoolable medium 120 comprises a plurality of load-bearing elements 121,122,123, best shown in FIGS. 3 and 4.

(13) In this embodiment, the plurality of load-bearing elements comprises three load-bearing elements 121,122,123.

(14) A portion of the load-bearing spoolable medium 120 is spooled about the winch apparatus 110.

(15) The winch apparatus 110 is configured to control paying out and/or paying in of the load-bearing spoolable medium 120. The winch apparatus 110 is configured to function as a detensioning device to reduce tension within the load-bearing spoolable medium 120.

(16) The load-bearing spoolable medium 120 defines an outboard or high tension portion 125, between the load 130 and the winch apparatus 110, and defines an inboard or low tension portion 126, on a side of the winch apparatus 110 opposite the load 130.

(17) The load-bearing spoolable medium 120 and the winch apparatus 110 are described in more detail with reference to FIGS. 2, 3 and 4.

(18) The load-bearing apparatus 100 includes an overboarding assembly 140 which is used to appropriately direct a spoolable medium 120 from a vessel (not shown) into the sea. Additionally, a heave compensator 142 is provided which provides dynamic compensation to the spoolable medium 120 to accommodate for heaving motion of the associated vessel.

(19) The load-bearing apparatus 100 comprises a guide 144 for guiding each of the load-bearing elements 121,122,123 towards a respective tension control apparatus 151,152,153. The tension control apparatuses 151,152,153 are provided to control, apply and/or adjust the tension of a respective load-bearing element 121,122,123, on an inboard portion 126 thereof.

(20) The tension control apparatus 151,152,153 is further described in more detail with reference to FIGS. 5 and 6.

(21) The load-bearing apparatus 100 further includes a storage apparatus 161,162,163, which in this embodiment is provided in the form of a plurality of storage baskets 161,162,163, which permit a respective load-bearing element 121,122,123 to be stored in a zero or near zero tension state.

(22) FIG. 2 shows a load-bearing apparatus 200 according to a second embodiment of the present invention, showing load-bearing spoolable medium 220 and winch apparatus 210. The load-bearing spoolable medium 220 and winch apparatus 210 are generally similar to the load-bearing spoolable medium 120 and winch apparatus 110 of FIG. 1, like part denoted by like numerals, incremented by ‘100’.

(23) The winch apparatus 210 has a contact surface 211 configured for engaging the load-bearing spoolable medium 220. Although not shown in the schematic representation of FIG. 2 for ease of representation, load-bearing spoolable medium 220 comprises a plurality of load-bearing elements arranged side-by-side on contact surface 211 of the winch apparatus 210.

(24) In the embodiment of FIG. 2, the contact surface 211 of the winch apparatus 210 comprises a plurality of circumferentially arranged support elements 212 or slats each having discrete contact surfaces which collectively define a drum contact surface.

(25) FIG. 3 shows a load-bearing apparatus 300 according to a third embodiment of the present invention, showing load-bearing spoolable medium 320 and winch apparatus 310. The load-bearing spoolable medium 320 and winch apparatus 310 are generally similar to the load-bearing spoolable medium 120 and winch apparatus 110 of FIG. 1, like part denoted by like numerals, incremented by ‘200’.

(26) In the embodiment of FIG. 3, the contact surface 311 of the winch apparatus 310 comprises a substantially continuous, flat, surface 313.

(27) FIG. 4 shows a load-bearing apparatus 400 according to a fourth embodiment of the present invention, showing load-bearing spoolable medium 420 and winch apparatus 410. The load-bearing spoolable medium 420 and winch apparatus 410 are generally similar to the load-bearing spoolable medium 420 and winch apparatus 410 of FIG. 1, like part denoted by like numerals, incremented by ‘300’.

(28) In the embodiment of FIG. 4, the contact surface 411 of the winch apparatus 410 comprises a grooved surface having groove 414. The groove 414 is arranged to receive and guide the plurality of load-bearing elements 421,422,423 on the contact surface 411 as the load-bearing elements 421,422,423 are wound about the winch apparatus 410.

(29) In the embodiments of FIGS. 3 and 4, the load-bearing spoolable medium 320,420 comprises three separate, distinct load-bearing elements 321,322,323 and 421,422,423 arranged side-by-side. Provision of a plurality of load-bearing elements 121,122,123, 321,322,323 and 421,422,423 arranged side-by-side permits reduction of a diameter of each of the load-bearing elements 121,122,123, 321,322,323 and 421,422,423 compared to a diameter of a corresponding single load-bearing medium that would be required to support the same load 130. One of the effects and advantages of such reduction in diameter of the load-bearing elements 121,122,123, 321,322,323 and 421,422,423 is that the diameter of the winch apparatus 110,310,410 used with such load-bearing elements 121,122,123, 321,322,323 and 421,422,423 may be reduced, therefore reducing costs, ease of handling, and safety.

(30) In this embodiment, each load-bearing element 321,322,323 and 421,422,423 comprises a synthetic fibre rope. The provision of three load-bearing elements significantly reduces the diameter appropriate for the winch apparatus 310,410, while maintaining the number of load-bearing elements relatively low to minimise difficulty of handling or risks of malfunction associated with a multiple rope system.

(31) For a load of 250Te, a standard 136 mm diameter single rope having a minimum break load (MBL) of 1125Te would give a safety factor of 4.5.

(32) For the same load capacity, each of the three load-bearing elements 321,322,323 and 421,422,423 of FIGS. 3 and 4 may have a diameter in the region of 70-90 mm, e.g. approximately 78 mm. This reduced diameter in each of the load-bearing elements allows reduction in the diameter of the associated winch apparatus 310,410.

(33) In other embodiments using two load-bearing elements (not shown), each of the two load-bearing elements may have a diameter in the region of 80-100 mm, e.g. approximately 88 mm. This reduced diameter in each of the load-bearing elements allows reduction in the diameter of the associated winch apparatus 310,410.

(34) In other embodiments using four load-bearing elements (not shown), each of the four load-bearing elements may have a diameter in the region of 50-80 mm, e.g. approximately 66 mm. This reduced diameter in each of the load-bearing elements allows reduction in the diameter of the associated winch apparatus 310,410.

(35) FIGS. 3 and 4 depict load-bearing elements 321,322,323 and 421,422,423 having a substantially circular cross-section. However, this is for ease of representation only, and other rope profiles may be equally suitable for use in the present invention, such as flat ropes, or the likes.

(36) The load-bearing elements 321,322,323 and 421,422,423 are substantially parallel to each other on the contact surface 311,411 of the winch apparatus 310,410, in a plane substantially parallel to an axis of rotation 315,415 of the winch apparatus 310,410, and tangential to the contact surface 311,411.

(37) In this embodiment, the load-bearing spoolable medium 320,420 defines three turns around the winch apparatus 310,410. It will be understood that the load-bearing spoolable medium 320,420 may define fewer, or more, turns, but only three turns are shown in FIGS. 3 and 4 for ease of understanding.

(38) The load-bearing elements 321,322,323 and 421,422,423 are provided in sequential order around the contact surface 311,411 of the winch apparatus 310,410. That is, each of the first, second and third turns (represented respectively by suffix a,b,c) defines in sequential order first, second and third load-bearing elements 321,322,323 and 421,422,423. A turn of a load-bearing element may be separated from an adjacent turn of the same load-bearing element, by the remaining load-bearing elements. As see on FIGS. 3 and 4, first load-bearing element 321a,421a of the first turn is separated from first load-bearing element 321b,421b of the second turn by second and third load-bearing elements 322a,323a,422a,423a of the first turn. Similarly, first load-bearing element 321b,421b of the second turn is separated from first load-bearing element 321c,421c of the third turn by second and third load-bearing elements 322b,323b,422b,423b of the second turn.

(39) In this embodiment, the diameter of each of the plurality of load-bearing elements 321,322,323 and 421,422,423 is identical.

(40) FIG. 5 is a side view of a tension control apparatus 551 according to a fifth embodiment of the present invention. The tension control apparatus 551 is generally similar to the tension control apparatus 151,152,153 of FIG. 1, like part denoted by like numerals, incremented by ‘400’.

(41) In the embodiment of FIG. 5, the tension control apparatus 551 comprises a tension control device 552 for engaging load-bearing element 521. The tension control device 552 is in the form of a track tensioner.

(42) FIG. 6 is a side view of a tension control apparatus 651 according to a sixth embodiment of the present invention. The tension control apparatus 651 is generally similar to the tension control apparatus 151,152,153 of FIG. 1, like part denoted by like numerals, incremented by ‘500’.

(43) In the embodiment of FIG. 6, the tension control apparatus 651 comprises a tension control device 652 for engaging load-bearing element 621. The tension control device 652 is in the form of a drum, winch or sheave.

(44) Referring back to FIG. 1, each tension control apparatus 151,152,153 is provided to control, apply and/or adjust the tension of a respective load-bearing element 121,122,123, on an inboard portion 126 thereof.

(45) In this embodiment, the tension control apparatus 151,152,153 are arranged to maintain a difference in tension between the load-bearing elements 121,122,123 at a predetermined level, e.g. below an upper limit such as below about 20%, e.g. below about 10%, e.g. below about 5%. In other embodiments, In another embodiment, the tension control apparatus 151,152,153 are configured to maintain or apply different tensions between the load-bearing elements. This may help accommodate, for example, operational or environmental requirements, fatigue or wear of one or more load-bearing elements, etc.

(46) In this embodiment, each tension control apparatus 151,152,153 comprises a respective sensing device 155,156,157 which is arranged to measure the tension of a respective load-bearing element 121,122,123 on an inboard portion 126 thereof.

(47) In this embodiment, each tension control apparatus 151,152,153 comprises a respective actuator 171,172,173, which in this embodiment forms part of a respective tension control device 151,152,153, and comprises a motor.

(48) By such provision, the tension of each load-bearing element 121,122,123 may be individually and independently controlled, which may allow the apparatus 100 and/or a user to apply a desired tension on a outboard portion 125 of each load-bearing element 121,122,123.

(49) It should be understood that the embodiments described herein are merely exemplary and that various modifications may be made thereto without departing from the scope of the present invention.