Cable handling bow for an overboarding system of a work platform

Abstract

A cable handling bow (2) for an overboarding system of a work platform has a cable retaining structure (4) for retaining a length of a cable, where the cable retaining structure (4) extends along a partially curved path (6). The path (6) has a first end (8) and an opposed second end (10), where the path (6) has a first straight segment (14) located between the first end (8) and the second end (10) and is spaced away from both ends (8, 10), such that a cable joint connecting two ends of a cable is placeable in the first straight segment (14), when the cable length is retained in the cable retaining structure (4).

Claims

1. A cable handling bow for an overboarding system of a work platform, the cable handing bow comprising: a cable retaining structure for retaining a length of a cable, wherein the cable retaining structure extends along a partially curved path, which path has a first end and an opposed second end, wherein the path has a first straight segment located between the first end and the second end and being spaced away from both ends, such that a cable joint connecting two ends of a cable is placeable in the first straight segment, when the cable length is retained in the cable retaining structure.

2. The cable handling bow according to claim 1, wherein the cable retaining structure has a gap that extends along the first straight segment.

3. The cable handling bow according to claim 1, wherein the gap is arranged asymmetrically on the cable handling bow.

4. The cable handling bow according to claim 1, wherein a first run length of the cable retaining structure from the first end to the first straight segment is smaller than a second run length of the cable retaining structure from the first straight segment to the second end.

5. The cable handling bow according to claim 4, wherein the second run length has at least double the size of the first run length.

6. The cable handling bow according to claim 1, wherein the path has a first curved segment arranged between the first end and the first straight segment, and a second curved segment arranged between the first straight segment and the second end.

7. The cable handling bow according to claim 1, wherein the path has a second straight segment arranged at the second end.

8. The cable handling bow according to claim 1, further comprising a supporting apparatus reaching into the gap and configured to support a cable joint.

9. The cable handling bow according to claim 8, wherein the supporting apparatus comprises a plurality of curved support surfaces distributed along the gap.

10. The cable handling bow according to claim 1, further comprising a traverse extending from a region adjacent to the first end of the path to a region adjacent to the second end of the path, wherein the traverse and the first straight section enclose an angle in the range of 20 to 45.

11. The cable handling bow according to claim 1, wherein the cable retaining structure comprises a trough.

12. A cable overboarding system for a work platform arrangeable on a vessel, comprising: a lowering device having a wire, and a cable handling bow according to claim 1 connected to the wire, wherein the wire is connected to the cable handling bow to lower the cable handling bow into the sea.

13. A work platform for performing a cable operation on a cable on a vessel having a vessel deck, wherein the work platform comprises: chutes for guiding the cable from the sea and onto the work platform, and an overboarding system according to claim 12, wherein the base frame and/or the bow supporting frame are at least partially arranged between the chutes.

14. The work platform according to claim 13, further comprising a number of modules, wherein at least some of the modules comprise a deck section and a support structure for supporting the deck section at a distance above the vessel deck, wherein each module is configured to be lifted separately onto and away from the vessel deck, wherein the deck sections of the modules together form a mezzanine deck on which the cable operation is performed, wherein the overboarding system is secured to the mezzanine deck, and wherein at least some of the equipment for performing the cable operation is stored below the mezzanine deck.

15. A method for overboarding a cable, comprising the steps of: providing a cable handling bow according to claim 1 on a deck in a substantially horizontal position, placing a cable length having a joint onto the cable handling bow, such that the joint is arranged in the first straight segment, tilting the cable handling bow into an upright position, and lifting and overboarding the cable handling bow from the deck.

Description

SHORT DESCRIPTION OF THE DRAWINGS

[0036] In the following description this invention will be further explained by way of exemplary embodiments shown in the drawings:

[0037] FIG. 1 shows a cable handling bow in a first perspective view.

[0038] FIG. 2 shows a cable handling bow in a second perspective view.

[0039] FIG. 3 shows a detail of a lug on the cable handling bow in a perspective view.

[0040] FIG. 4 shows a detail of the curved support surface in a perspective view.

[0041] FIG. 5 shows a work platform in a perspective view.

[0042] FIGS. 6a to 6i show a sequence of overboarding a cable in top views (FIGS. 6a to 6e) and perspective views (FIGS. 6f to 6i).

[0043] FIG. 7a shows a hook securing the cable handling bow to the bow supporting frame.

[0044] FIG. 7b shows the hook of FIG. 7b in a released state to release the cable handling bow.

DETAILED DESCRIPTION OF THE INVENTION

[0045] FIG. 1 shows a cable handling bow 2 for an overboarding system of a work platform. The work platform will be described in more detail further below.

[0046] The cable handling bow 2 has a cable retaining structure 4 that extends along a partially curved path 6 from a first end 8 to a second end 10. The path 6 may be considered an imaginary or notional line that defines the general arcuate shape of the cable handling bow 2.

[0047] The path 6 has an arcuate or arch shape with a first curved segment 12, a first straight segment 14, a second curved segment 16 and a second straight segment 18. The first curved segment 12 and the second curved segment 16 enclose a gap 20, wherein the gap 20 extends along the first straight segment 14. The second straight segment 18 is arranged between the second end 10 and the second curved segment 16. The curved segments 12 and 16 have substantially the same radius of curvature, which may correspond to the acceptable bending radius for the cable to be handled, or may be slightly above. A run length 13 from the first end 8 to the first straight segment 14 is smaller than a run length 17 from the first straight segment 16 to the second end 10. The general shape of the cable handling bow 2 may be summarized as a partially flattened, asymmetrically skewed semi-circle.

[0048] The cable retaining structure 4 is formed as a trough, an exemplary cross-section of which is shown in detail A. The profile of the cable retaining structure 4 may, for example, comprise a planar base surface 22, from which two spaced apart sidewalls 24 extend transverse thereto and define an intermediate space that widens outwardly with increasing distance to the base surface 22. Thus, the profile may lead to a funneling and self-centering function to hold the cable in the cable retaining structure 4.

[0049] The first straight segment 14 and the gap 20 allow to receive an elongated, stiff cable joint on the cable handling bow 2. Such a cable joint may be formed by a metallic and/or plastic material and has a clearly lower flexibility than the cable and cannot be bent with the same bending radius as the cable without becoming plastically deformed. Hence, to avoid plastic deformation or a break, such a cable joint would need to be placed along a straight line. The cable handling bow 2 allows the cable joint to be integrated into the gap 20 and/or the first straight segment 14, respectively. Cable portions that are directly adjacent to the cable joint rest on the curved segments 12 and 16 and form a smooth transition between the cable and the joint.

[0050] For supporting the joint on the cable handling bow 2, a supporting apparatus 26 is provided, which exemplarily reaches into the gap 20 from inside the cable handling bow 2. In this exemplary embodiment, the supporting apparatus 26 comprises several spaced apart curved support surfaces 28 that are distributed along the gap 20. They may be attached to an angled beam 36 that extends parallelly to and along the first straight segment 14.

[0051] The cable handling bow 2 may be formed as a steel construction. In this exemplary embodiment, the cable retaining structure 4 is supported by a framework structure 30 having a plurality of interior frame members 32, a traverse 34 and the angled beam 36. The traverse 34 may extend parallel to a connection line between the first end 8 and the second end 10 and substantially spans over the whole width of the bow 2.

[0052] A lifting yoke 38 is pivotably connected to the framework structure 30. Exemplarily, it is located in a transition region between the first straight segment 14 and the second curved segment 16. It is attached to two upright frame members 32 of the framework structure by means of two spaced apart hinges. Exemplarily, the lifting yoke 38 is arranged on a substantially triangular sub frame to provide a high stability. The lifting yoke 38 allows to attach the cable handling bow 2 to a wire of a winch or a crane to be lifted and lowered from the overboarding system.

[0053] FIG. 2 shows the cable handling bow 2 from the side that is hidden in FIG. 1. In this illustration, a lug 40 arranged in a central region of the framework structure 30 is shown. The lug 40 is configured to receive a hook from a tilting device, on which the bow may be placed. The lug 40 is configured to receive the hook to temporarily secure the cable handling bow 2 to the tilting device, which will be explained further below.

[0054] FIG. 3 shows the lug 40 in a detail view. The lug 40 comprises a transverse rod 42, which is parallel to the traverse 34, and which is held between two spaced apart flanges 44. The flanges 44 have an introduction section created by flange sections 46 extending in a direction away from the traverse. 34. A hook that is advanced to the transverse rod 42 will be guided by the flange sections 46 towards the transverse rod 42. Merely as an example, the lug 40 is attached to the framework structure 30 by bolts 48 and a counter plate 50.

[0055] FIG. 4 shows a support surface 28 in detail. The angled beam 36 may have an internal structure, to which the support surface 28 can be attached through a bolt connection 52. The support surface 28 may be arranged on a planar flange 54, e.g., by welding a bent sheet metal part 56 to a correspondingly shaped cutout 58 of the flange 54.

[0056] FIG. 5 shows a work platform 60 in a perspective view from above. The work platform may be a part of or installed on a vessel or a boat. The work platform 60 comprises two spaced apart chutes 62 and 64 for guiding a cable from the sea and onto the work platform 60. Exemplarily, the chutes 62 and 64 may extend over an aft side 66 of the work platform 60. The chutes 62 and 64 are considered well known in the art, and will not be described in further detail.

[0057] The work platform 60 has a number of modules 68, 69, 70, 72, 74, 76, and 78, which can be placed adjacent to each other on a vessel deck. The modules together are configured to form a mezzanine deck 80 above the respective vessel deck and a protective lower deck 82 below the mezzanine deck 80. On the mezzanine deck 80, an overboarding system 84 is provided.

[0058] Each of the modules 68, 69, 70, 72, 74, and 76 may have a deck section and a support structure for supporting the deck section at a distance above the vessel deck. The modules 66, 68, 70, 72, 74, 76, and 78 may be configured to perform different tasks.

[0059] For example, the modules 68, 69 may be storage modules arranged at the aft side 66. Both modules 68 and 69 may be used for storing equipment for performing a cable operation. The module 70 may be a lift module a lift configured to lift equipment between an internal floor and the deck section. Module 72 may be a tensioner module having a tensioner lift and a cable tensioner, wherein the tensioner lift may be configured to lift the cable tensioner between a position above the deck section of the tensioner module 72 and a position below the deck section of the tensioner module 72. The modules 74 and 76 may comprise containers for storing equipment.

[0060] Module 78 may be a winch module that has a deck section, which may not cover the entire part of the winch module 78. Also, it may not comprise an internal floor. The winch module 78 may comprises a winch support for supporting winches in a position below the deck section of the winch module 78. For example, three winches 79a, 79b, 79c may be used, wherein one of the winches 79a, 79b, 79c, e.g. 79b, may be associated with the overboarding system 84, and wherein the two other winches 79a and 79c may be used for lifting the ends of two cable sections.

[0061] The side opposed to the aft side 66 will be referred to as front side 86. A central longitudinal axis A1 of the work platform 60 is defined as a central axis between the aft side 66 and the front side 86 of the work platform 60.

[0062] In the illustration of FIG. 5, the cable handling bow 2 as a part of the overboarding system 84 is placed on the mezzanine deck 80 at the front side 86. It is arranged to be in a horizontal orientation. The cable handling bow 2 may be stored in this position to be ready for an overboarding process after conducting the desired cable operation. The overboarding process is shown in form of a sequence in FIGS. 6a to 6i.

[0063] FIG. 6a shows the mezzanine deck 80 in a top view with a first cable section 88 that runs over the chute 62 and along a first cable guide 96 to a jointing area 92. A second cable section 90 runs over the chute 64 and along a second cable guide 98 to an opposed side of the jointing area 92. Both cable sections 88 and 90 are connected with a cable joint 94, which in this example is a stiff/rigid cable joint having an elongated shape. Thus, the cable sections 88, 90 and the cable joint 94 form a cable 100 with an integrated joint 94. On the jointing area 92, a tent may be erected to protect the jointing area 92 from water, dirt, wind, and other influences.

[0064] In this illustration, the cable handling bow 2 is placed further to the aft side 66, i.e. between the chutes 62 and 64 and the jointing area 92. After finishing the cable operation, the cable guides 96 and 98 are removed, and the cable handling bow 2 is moved towards the cable joint 94, i.e. further to the rear side 86. FIG. 6b shows the cable handling bow 2 being directly adjacent the cable 100 and the cable joint 94 being arranged in the first straight segment 14 of the cable handling bow 2.

[0065] During the cable operation, the radius of curvature of the cable sections 88 and 90 may be larger than the acceptable bending radius of the cable 100, to prevent an excessive bending due to unavoidable movements of the vessel with the cable sections 88 and 90 reaching into the open sea. As indicated by the arrows, the bending radii of curvature of the cable 100 at both sides of the cable handling bow 2 is reduced by tensioning the cable 100 after placing the cable handling bow 2.

[0066] As shown in FIG. 6c, the shape of the cable 100 conforms the curvature of the cable retaining structure 4. Hence, the cable 100 with the cable joint 94 arranged in the gap 20 is turned about 180 at an acceptable bending radius over the cable handling bow 2 and the cable 100 runs straightly from the cable handling bow 2 over the chutes 62 and 64 into the open sea.

[0067] As a next step, as shown in FIG. 6d, a bow supporting frame 65 of a tilting device 63 is moved from a position between the chutes 62 and 64 towards the front side 86 until it reaches beneath the cable handling bow 2. In this position, the bow supporting frame 65 engages the cable handling bow 2 by moving a hook into the lug 40 (shown in reverse in FIG. 6h).

[0068] Then, the bow supporting frame 65 moves the cable handling bow 2 towards the aft side 66 and the chutes 62 and 64 onto a base frame 67, as shown in FIG. 6e. In doing so, the excessive lengths of the cable sections 88 and 90 are continuously submerged.

[0069] FIG. 6f shows a perspective view of the bow supporting frame 65 being arranged in the resulting horizontal position with the cable 100 on the cable handling bow 2 directly in front of the chutes 62 and 64.

[0070] As shown in FIGS. 6g and 6h, the bow supporting frame 65 is tilted upwards into an upright position, until the bow supporting frame substantially perpendicularly extends from the mezzanine deck 80 upwards, which corresponds to the illustration of FIG. 6h.

[0071] At a top of the bow supporting frame 65, a sheave 104 is provided, which guides a winch wire 106 from the winch 79b to the yoke 38 of the cable handling bow 2. The winch 79b may be arranged in the winch module 78 further to the front side 86, as explained above. By pivoting the sheave 104 further to the aft side 66, the winch wire 106 will be guided into a greater distance to the bow supporting frame 65 and allows to space the cable handling bow 2 further apart from the bow supporting frame 65. Resultantly, the cable handling bow 2 is sufficiently spaced apart from the chutes 62 and 64 and can be lowered into the open sea to overboard the cable 100.

[0072] FIGS. 7a and 7b show a hook 102 swivably supported on the bow supporting frame 65. In FIG. 7a, the hook 102 engages the lug 40 of the cable handling bow 2 to secure the cable handling bow to the bow supporting frame 65. This may be done during moving the cable handling bow 2 towards the chutes 62 and 64 and tilting upwards. The hook 102 will be released from the lug 40 to release the cable handling bow 2 after reaching the position shown in FIG. 6h. Swiveling the hook to selectively engage or disengage the lug 40 may be achieved by a drive device, such as a hydraulic actuator.

REFERENCE NUMERALS

[0073] 2 cable handling bow [0074] 4 cable retaining structure [0075] 6 path [0076] 8 first end [0077] 10 second end [0078] 12 first curved segment [0079] 13 first run length [0080] 14 first straight segment [0081] 16 second curved segment [0082] 17 second run length [0083] 18 second straight segment [0084] 20 gap [0085] 22 base surface [0086] 24 sidewall [0087] 26 supporting apparatus [0088] 28 support surface [0089] 30 framework structure [0090] 32 interior frame members [0091] 34 traverse [0092] 36 angled beam [0093] 38 lifting yoke [0094] 40 lug [0095] 42 transverse rod [0096] 44 flange [0097] 46 flange section [0098] 48 bolt [0099] 50 counter plate [0100] 52 bolt connection [0101] 54 flange [0102] 56 bent sheet metal part [0103] 58 cutout [0104] 60 work platform [0105] 62 chute [0106] 63 tilting device [0107] 64 chute [0108] 65 bow supporting frame [0109] 66 aft [0110] 67 base frame [0111] 68 module [0112] 69 module [0113] 70 module [0114] 72 module [0115] 74 module [0116] 76 module [0117] 78 module [0118] 79(a-c) winch [0119] 80 mezzanine deck [0120] 82 lower deck [0121] 84 overboarding system [0122] 86 front [0123] 88 first cable section [0124] 90 second cable section [0125] 92 jointing area [0126] 94 cable joint [0127] 96 first cable guide [0128] 98 second cable guide [0129] 100 cable [0130] 102 hook [0131] 104 sheave [0132] 106 winch wire [0133] A1 central longitudinal axis