TUG WITH AN ALL AROUND TOWING INSTALLATION

Abstract

An all around towing system (33) for a tug (31) comprising a heavy plate (40) mounted on a deck of the tug, an upper rail segment (42) and a lower rail segment (44) disposed on the upper and lower surfaces of an outer edge of the heavy plate, respectively, a carriage (46) movable along the upper and lower rail segments, a set of bearing wheels (47, 48) arranged for guiding the carriage along the upper and lower rail segments, characterized in that the heavy plate further comprises respective upper and lower grooves (43, 45) on the upper and lower surfaces of the heavy plate, and in that the upper and lower rail segments are respectively mounted in the upper and lower grooves of the heavy plate.

Claims

1. An all around towing system (33) for a tug (31) comprising: a heavy plate (40) mounted on a deck (32) of the tug; an upper rail segment (42) and a lower rail segment (44) disposed on the upper and lower surfaces towards an outer edge of the heavy plate, respectively; a carriage (46) movable along the upper and lower rail segments; and a set of bearing wheels (47, 48) arranged for guiding the carriage along the upper and lower rail segments; characterized in that the heavy plate further comprises respective upper and lower grooves (43, 45) on the upper and lower surfaces of the heavy plate and in that the upper and lower rail segments are respectively mounted in the upper and lower grooves of the heavy plate; wherein a plurality of bolt connections formed between the upper and lower rail segments and the heavy plate is positioned along the upper and lower rail segments.

2. The all around towing system (33) according to claim 1, wherein the upper and lower rail segments (42, 44) are bolted in the upper and lower grooves (43, 45), respectively.

3. The all around towing system (33) according to claim 1, wherein the upper and lower rail segments (42, 44) are bolted through holes in the heavy plate (40) to the rail segments on the opposing top and bottom surfaces.

4. The all around towing system (33) according to claim 1, wherein the plurality of bolt connections formed between the upper and lower rail segments and the heavy plate are positioned at between 15% to 40% of the width of the upper and lower rail segments measured from the inner curvature of the upper and lower rail segments (42, 44).

5. The all around towing system (33) according to claim 1, wherein the carriage (46) has at least two rigid parts (61, 62) connected to each other.

6. The all around towing system (33) according to claim 5, wherein the carriage (46) has at least two guiding structures (59) suitably disposed on the two rigid parts (61, 62) of the carriage (46) for connection to a split towline (60) and a towline (35) for towing an object.

7. The all around towing system (33) according to claim 6, wherein the guiding structures (59) are arranged and disposed on the carriage at a distance of at least 20% of the carriage length measured from half length of the carriage (46).

8. The all around towing system (33) according to claim 6, wherein the towline (35) is connected to the split towline (60) which forms a triangle connection (34) with a maximum split angle of 60.

9. The all around towing system (33) according to claim 6, wherein the split towline (60) has two ends passing through the guiding structures (59) and the ends are connected to each other at half length of the carriage (46) forming a closed loop triangle.

10. The all around towing system (33) according to claim 6, wherein the split towline (60) has two ends passing through the guiding structures (59) and the ends are connected by means of a release system.

11. The all around towing system (33) according to claim 6, wherein the guiding structures (59) have a fixed curved smooth surface.

12. The all around towing system (33) according to claim 6, wherein the guiding structures (59) have a rolling surface.

13. The all around towing system (33) according to claim 5, wherein the carriage (46) has two rigid parts (61, 62) which are connected by a marginally flexible structure (63).

14. The all around towing system (33) according to claim 5, wherein the carriage (46) has two rigid parts (61, 62) with a plurality of flexible blocks (65) mounted between the rigid parts.

15. The all around towing system (33) according to claim 1, wherein the set of bearing wheels comprises: at least two upper main bearing wheels (47) arranged and disposed on the upper surfaces of the carriage for guiding the carriage along the upper rail segment (42); and at least two lower main bearing wheels (48) arranged and disposed on the lower surfaces of the carriage for guiding the carriage along the lower rail segment (44).

16. The all around towing system (33), according to claim 15, wherein the upper main bearing wheels (47) are arranged and disposed on the upper and inner half surface of the carriage for guiding the carriage (46) along the inner side of the upper rail segment (42) and the lower main bearing wheels (48) are arranged and disposed on the lower and inner half surface of the carriage for guiding the carriage along the inner side of the lower rail segment.

17. (canceled)

18. The all around towing system (33) according to claim 15, wherein each of the upper main bearing wheels (47) is provided with a flange (49) and each of the lower main bearing wheels (48) is provided with a flange (50).

19. (canceled)

20. The all around towing system (33) according to claim 15, further comprising at least two upper wheels (53) arranged and disposed on the upper and outer half surface of the carriage (46) for guiding the carriage along the outer side of the upper rail segment (42); and at least two lower wheels (54) arranged and disposed on the lower and outer half surface of the carriage (46) for guiding the carriage along the outer side of the lower rail segment.

21. (canceled)

22. The all around towing system according to claim 20, wherein the additional upper wheel (53) is provided with a flange (55) and the additional lower wheel (54) is provided with a flange (56).

23. (canceled)

24. The all around towing system (33) according to claim 20, wherein the additional upper and lower wheels (53, 54) are fitted with an eccentric bushing.

25. The all around towing system (33) according to claim 15, wherein the upper main bearing wheels (47) and lower main bearing wheels (48) have a vertical rotation axis of 90 degrees perpendicular to the heavy plate (40).

26. The all around towing system (33) according to claim 15, wherein each upper main bearing wheel (47) is arranged with its flange (49) on the upper side of the upper main bearing wheel aligning with the upper side of the upper rail segment (42) and each lower main bearing wheel (48) is arranged with its flange (50) on the lower side of the lower main bearing wheel aligning with the lower side of the lower rail segment (44).

27. (canceled)

28. The all around towing system (33) according to claim 15, wherein the upper main bearing wheels (47, 51) and lower main bearing wheels (48) are distributed evenly along the upper and lower surfaces of the carriage (46).

29. The all around towing system (33) according to claim 1, wherein the heavy plate (40) has either a circular shape or an oval or elliptical shape.

30. (canceled)

31. The all around towing system (33) according to claim 29, wherein the upper and lower rail segments (42, 44) have either a circular profile or an oval or elliptical profile.

32. (canceled)

33. The all around towing system (33) according to claim 1, wherein both inner and outer diameters of the circumference of the upper rail segment (42) and lower rail segments (44) are equivalent in that the upper and lower rail segments are laterally aligned to each other.

34. The all around towing system (33) according to claim 1, wherein the upper groove (43) has a smaller diameter than the lower groove (45).

35. The all around towing system (33) according to claim 1, wherein the length of the carriage is at least 5% of the outer circumference of the rail segments (42, 44).

36. The all around towing system (33) according to claim 1, wherein the length of the carriage is in the range of 10% to 20% of the outer circumference of the rail segments (42, 44).

37. The all around towing system (33) according to claim 1, wherein the outer edge of the upper groove (43) has a smaller diameter than the inner edge of the lower groove (45).

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0034] The present invention will become more clearly understood from the following description of the embodiments thereof, when taken in conjunction with the accompanying drawings. However, the embodiment and the drawings are given only for the purpose of illustration and explanation, and are not to be taken as limiting the scope of the present invention, the scope of which is to be determined by the set of appended claims.

[0035] FIG. 1 shows a conventional all around towing system on a tug in perspective view with main components;

[0036] FIG. 2 shows a conventional carrousel towing system in section view at a set of wheels;

[0037] FIG. 3 shows a conventional DOT towing system in section view at a set of wheels;

[0038] FIG. 4 shows an all around towing system according to an embodiment of the invention;

[0039] FIG. 5 shows a sectional view of the all around towing system;

[0040] FIG. 6 shows the all around towing system in a perspective view from an angle from above; and

[0041] FIG. 7 consisting of FIGS. 7a and 7b shows the carriages with two rigid parts with flexible connection structures.

DETAILED DESCRIPTION OF THE EMBODIMENT

[0042] The tug 1 represented in FIG. 1 is provided with a central deck 2, a circular towing installation 3, a towing hook 4 and a towline 5 to the ship towed (not shown). Inside the towing ring is the accommodation 6 and on top of the accommodation the wheelhouse 7 and funnels 8. The towing installation can for example consists of a circular rotating ring extending all around the circular fixed structure by means of rollers/bearings.

[0043] FIG. 2 represents a cross section of the carrousel towing system with the steel structure of the tug's hull 11, the lower rail 12 and the upper rail 13, the box shaped rotating circular carrousel ring structure 14 and the upper load bearing wheel 15 and the lower load bearing wheel 16. The upper load bearing wheel has a flange 17 on the lower edge to prevent the carrousel structure from moving upward. The same applies to the lower load bearing wheel with flange 18. The arrow 19 indicates the direction of the outward towing force. Since the carrousel forms a ring structure all around, there is no need for additional wheels to prevent the ring structure to move outward. The rotating axis 20 of the load bearing wheels is positioned vertically.

[0044] FIG. 3 represents a cross section of the DOT system with the steel structure of the tug's hull 21, the single horizontally mounted rail structure 22, supported by two girders 23. The rotating structure is formed by two carriages, one of them shown simplified in section with a heavy plate 24 fitted with again load bearing wheels on the outer side 25 and on the inner side 26. The load bearing wheels are equipped with flange 27 on wheel 25 and flange 28 on wheel 26 to prevent the rotating structure from moving upward. The arrow 29 indicates again the outward towing force and the rotating axis 30 of the wheels is again vertically. Further a number of smaller supporting wheels are fitted to counter the gravity force (not shown).

[0045] The tug 31 represented in FIG. 4 is according to an embodiment of the present invention. It is provided with a central deck 32, a circular towing installation 33, a triangular connection 34 and a towline 35 to the ship towed (not shown). Inside the towing ring is the accommodation 36 and on top of the accommodation, the wheelhouse 37 and funnels 38. The towing installation 33 includes a fixed heavy plate 40, a fixed circular support 41 and a rotating outer carriage which is rotatable 360 degrees with respect to the tug 31 about the central deck 32.

[0046] FIG. 5 represents a sectional view of the towing system 33 according to the invention, with the ship's structure formed by a heavy thick horizontal plate 40, a circular support 41, an upper rail segment 42 positioned in the upper groove 43 in the heavy plate and a lower rail segment 44 positioned in the lower groove 45. Further, the carriage frame 46 with an U-shaped form fitted with two upper main bearing wheels 47 and lower main bearing wheels 48. The upper main bearing wheels are arranged and positioned on the upper and inner half surface of the carriage 46 for guiding the carriage 46 along the inner side of the upper rail segment 42. The lower main bearing wheels 48 are arranged and positioned on the lower and inner half surface of the carriage 46 for guiding the carriage 46 along the inner side of the lower rail segment 44. The upper and lower main bearing wheels 47, 48 are each equipped with a flange 49 of upper wheel 47 and flange 50 of lower wheel 48, respectively to prevent the carriage 46 from moving up and downward. The upper and lower main bearing wheels 47, 48 have a vertically rotating axis 51. The arrow 52 indicating the outward towing force and the rotating axis 51 is again vertically.

[0047] Further, a set of additional outer wheels 53, 54 are provided on the upper and lower surfaces of the carriage 46. The carriage frame 46 is fitted with additional upper wheels 53 and additional lower wheel 54. The additional upper wheels 53 are arranged and positioned on the upper and outer half surface of the carriage 46 in contact with the outer side of the upper rail segment 42. The additional lower wheels 54 arranged and positioned on the lower and outer half surface of the carriage 46 in contact with the outer side of the lower rail segment 44. The additional upper and lower wheels 53, 54 are each equipped with a flange 55 of upper wheel 53 and the flange 56 of lower wheel 54, respectively. Also, the additional upper and lower wheels 53, 54 have a vertically rotating axis 57.

[0048] FIG. 6 represents the towing system in perspective view with the ship's structure 58, the heavy thick plate 40, the upper rail segment 42, the towing system 33, the two guiding structures 59 and the towline 35 from the assisted ship. The carriage 46 is formed by two rigid parts 61, 62 connected to each other. Each of the guiding structures 59 is mounted on the surface of each rigid part 61, 62 of the carriage. The towline divides into two line parts 60 with internal angle , which are connected to the guiding structures 59 or are guided through the guiding structures 59 and run from the outside towards the centreline of the carriage 46. Preferably the angle is between 45 and 75. The two line parts 60 can have a circular section or a flat rectangular section. The flat rectangular section can be used with smaller diameter guiding structures, because the minimal bending ratio is defined by radius of the guiding structure divided by the radius of the line. The two lines can also consist of standard lifting slings with flat sections and integrated connection eyes on both ends.

[0049] The right part 61 of the carriage 46 is shown transparent with internals and showing the main upper bearing wheels 47, the additional upper wheel 53 and the additional lower wheel 54. The left rigid part 62 of the carriage 46 is shown solid with main upper bearing axle 66 and an additional upper axle 67.

[0050] FIG. 7 represents the carriages in the same perspective view as in FIG. 6, but without surrounding structures for clarity. The carriage in FIG. 7a consists of two guiding structures 59, a rigid right carriage part 61 and a rigid left carriage part 62 connected by a marginally flexible structure 63. This can be a flexible steel plate bolted or welded to the rigid parts. The carriage in FIG. 7b consists of two guiding structures 64, composed of either a fixed or rotating roller, a rigid right part 61 and a rigid left part 62. Between both parts a flexible structure is fitted, in this drawing shown as two rubber fender blocks 65 with only take compressive forces. Also, other structures with hinges and sliding faces can be considered.

[0051] Although the invention has been described above with reference to a preferred embodiment, numerous modifications may be made without departing from the scope of the present application. The all around towing installation may be constructed in all kind of different arrangements of rails, wheels and rollers both on fully circular shapes and on oval or non-circular shapes. The design is intended for unrestricted all around operation, but the design may be used for only part rotation, e.g. rails over a half circle from one side to the other over the aft deck.

[0052] Instead of upper and/or lower rail segments, the heavy plate (groove) surface may also be treated to increase the hardness (or by adding material) and thereby allowing to operate the bearing wheels directly on the heavy plate without the need for additional rails.