NL2023375B1

NL2023375B1 - Vessel with hoisting device

Info

Publication number: NL2023375B1
Application number: NL2023375A
Authority: NL
Inventors: Cornelius Van Grieken Gerardus
Original assignee: Kenz Figee Group B V
Priority date: 2019-06-25
Filing date: 2019-06-25
Publication date: 2021-02-01

Abstract

The invention relates to a vessel with a hoisting device, wherein the vessel comprises a hull with a deck and the hoisting device comprises two supports on the hull, two legs that are hingeably connected to one of the supports, a cross beam supported by the legs and spaced apart from the deck, and a hoisting cable suspended from the cross beam, wherein the legs are hingeable around a horizontally extending' first hinge axis between. a retracted. position, and an extended position, wherein the cross beam is hingeably connected to the legs and is hingeable with respect to the legs around a horizontally extending second hinge axis that extends substantially parallel to the first hinge axis, and wherein the hoisting device comprises an angle adjuster‘ that is connected. to the cross beam for adjusting the angle of the cross beam with respect to the legs.

Description

P136483NL00 Vessel with hoisting device

BACKGROUND The invention relates to a vessel with a hoisting device, more specifically a vessel for handling submarine cables on a sea.

SUMMARY OF THE INVENTION Known offshore vessels, more specifically vessels that handle submarine cables, are equipped with a hoisting device in the form of a hoisting frame or A-frame at the stern of the vessel. A typical hoisting frame comprises two legs that support a cross beam between them. The entire hoisting frame is hingeable between a position in which the cross beam extends above the deck, and a position in which the cross beam extends beyond the stern of the vessel. Generally the hoisting frame is outfitted with hoisting and handling equipment in order to be used to lower and guide submarine cables to the seabed and/or to hoist loads such as subsea ploughs or cable trenchers from the deck into the sea. The hoisting capacity of a hoisting frame may vary from one to several hundreds of tons. As the known hoisting devices handle heavy loads at an offshore location, the hoisting frame is exposed to high forces and harsh environmental conditions. As a result the legs and cross beam of the hoisting frame are constructed from big and heavy steel members. Likewise the equipment fitted on the hoisting device is big and heavy as to withstand the extreme loads. Furthermore the hoisting device, and the equipment fitted thereon, is subject to high wear and tear. Therefore the hoisting device requires frequent maintenance and repair works. A further disadvantage of known hoisting devices is that with hinging the hoisting frame the hoisting cable moves relative to the cross beam. This relative movement may lead to snag loads on the hoisting cable or to collisions of the hoisted object with the vessel, hoisting device or other equipment.

It is an object of the present invention to provide a vessel with a hoisting device that addresses at least one of the problems described above.

According to a first aspect, the invention provides a vessel with a hoisting device, wherein the vessel comprises a hull with a deck and the hoisting device comprises two supports on the hull, two legs that are at one end hingeably connected to one of the supports, a cross beam supported by the legs at the opposite ends thereof and spaced apart from the deck, and a hoisting cable suspended from the cross beam, wherein the legs are hingeable around a horizontally extending first hinge axis between a retracted position in which the cross beam extends above the deck, and an extended position in which the cross beam extends beyond the deck, wherein the cross beam is hingeably connected to the legs and is hingeable with respect to the legs around a horizontally extending second hinge axis that extends substantially parallel to the first hinge axis, and wherein the hoisting device comprises an angle adjuster that is connected to the cross beam for adjusting the angle of the cross beam with respect to the legs.

The main hoisting force exerted on the cross beam is constant in a downward direction. By keeping the orientation of the cross beam constant by means of the angle adjuster, the loads experienced by the cross beam are similar in all positions of the hoisting device. The hinged connections between the cross beam and the legs ensure that hardly any moment of force is transferred from the cross beam to the legs in the plane transverse to the second hinge axis. As a result the loads on the cross beam and the legs can be determined more accurately and they can be dimensioned more accurately whereby they can be lighter and more slender. Due to the constant orientation of the cross beam the equipment mounted thereto is subject to more uniform and unidirectional loads. The equipment can therefore be dimensioned lighter and smaller. The uniform and unidirectional loads can be especially advantageous for moving and rotating equipment as this equipment will wear and tear less under such loads.

In an embodiment the angle adjuster keeps the cross beam in substantially the same orientation with respect to the deck while the legs hinge around the first hinge axis. The cross beam is in a substantially horizontal orientation parallel to the deck which is favorable for handling cables or hoisting objects. The loads on the cross beam can be determined in a straightforward way.

In an embodiment the angle adjuster comprises a stabilizing rod that extends substantially along and spaced apart from the legs and that is hingeably connected to the cross beam and to one of the supports. The stabilizing rod and the legs form a parallel mechanism that keeps the cross beam in the same stable orientation with respect to the deck while the legs hinge around the first hinge axis.

In an embodiment the hoisting device comprises a stabilizing rod at each leg. Two stabilizing rods provide ample stability to the cross beam while their position near the legs provides for free space below the cross beam to handle cables and objects.

In an embodiment the hoisting device comprises a hydraulic cylinder that is connected between one of the legs and one of the supports for moving the legs between the retracted position and the extended position. Hydraulic cylinders are widely used in offshore operations and provide for a simple and robust actuator for hinging the legs.

In an embodiment the hoisting cable is guided from near the first hinge axis to the cross beam. By guiding the hoisting cable via the pivot points of the legs the length of the hoisting cable is constant while the legs hinge around the first hinge axis. This configuration ensures that the hoisting cable has a substantially constant length below the cross beam while the legs hinge around the first hinge axis. The constant length results in more predictable and safer handling of cables and objects.

In an embodiment the hoisting cable is guided from near the first hinge axis to the cross beam along one of the legs. Guiding the hoisting cable along a leg provides for free space below the cross beam to handle cables and objects.

In an embodiment the hoisting device comprises a trolley frame that is supported by and that is movable along the cross beam, and wherein the hoisting cable is suspended from the cross beam by the trolley frame. The trolley frame makes it possible to move the hoisting cable with respect to the deck in a horizontal direction. This configuration can make handling of cables and objects at various locations on the deck easier and safer.

In a further embodiment the hoisting device comprises a trolley subframe that 1s movable along the cross beam, wherein the trolley subframe and the trolley frame are arranged to have a fixed mutual displacement ratio with respect to the cross beam, wherein the hoisting cable is guided from the cross beam via the trolley subframe to the trolley frame and comprises a reeving between the trolley frame and the trolley subframe that compensates for the fixed mutual displacement ratio such that the hoisting cable has a constant length suspended below the cross beam while the trolley frame moves along the cross beam. The configuration of the trolley frame, the trolley subframe and the reeving provides a single hoisting cable with a constant length below the cross beam. A single hoisting cable is easy to handle, easy to pass through equipment and does not twist. The constant length of the 5 hoisting cable results in more predictable and therefore safer handling of cables and objects.

In a further embodiment the trolley frame and the trolley subframe are movable along the cross beam in the same direction.

In an embodiment the hoisting device comprises a hydraulic trolley cylinder that is connected between the cross beam and the trolley subframe for moving the trolley frame along the cross beam. Hydraulic cylinders are widely used in offshore operations and provide for a simple and robust actuator for moving the trolley frame. Connecting the trolley cylinder between the cross beam and the trolley subframe benefits the required installation length of the trolley cylinder to move the trolley frame along the cross beam.

In an embodiment the hoisting device comprises a trolley cable that 1s connected between the trolley frame and the trolley subframe and that comprises a reeving between the trolley frame and the trolley subframe that determines the fixed mutual displacement ratio of the trolley frame and the trolley subframe. The cable provides a simple and robust connection between the trolley frame and the trolley subframe.

In an embodiment the fixed mutual displacement ratio of the trolley frame and the trolley subframe is 2:1.

According to a second aspect, the invention provides a vessel with a hoisting device, wherein the vessel comprises a hull and a deck and the hoisting device comprises two supports on the hull, two legs that are at one end hingeably connected to one of the supports, a cross beam supported by the legs at the opposite ends thereof and spaced apart from the deck, and a hoisting cable suspended from the cross beam, wherein the legs are hingeable around a horizontally extending first hinge axis between a retracted position in which the cross beam extends above the deck, and an extended position in which the cross beam extends beyond the deck, wherein the hoisting device comprises a trolley frame that is supported by and that is movable along the cross beam and a trolley subframe that is movable along the cross beam, wherein the trolley subframe and the trolley frame are arranged to have a fixed mutual displacement ratio with respect to the cross beam, and wherein the hoisting cable is guided from the cross beam via the trolley subframe to the trolley frame and comprises a reeving between the trolley frame and the trolley subframe that compensates for the fixed mutual displacement ratio such that the hoisting cable has a constant length suspended below the cross beam while the trolley frame moves along the cross beam. The constant length of the hoisting cable results in more predictable and therefore safer handling of cables and objects.

In an embodiment the trolley frame and the trolley subframe are movable along the cross beam in the same direction.

In an embodiment the hoisting cable is guided from near the first hinge axis to the cross beam. By guiding the hoisting cable via the pivot points of the legs the length of the hoisting cable is constant while the legs hinge around the first hinge axis. This configuration ensures that the hoisting cable has a substantially constant length below the cross beam while the legs hinge around the first hinge axis.

In an embodiment the hoisting device comprises a hydraulic trolley cylinder that is connected between the cross beam and the trolley subframe for moving the trolley frame along the cross beam. Hydraulic cylinders are widely used in offshore operations and provide for a simple and robust actuator for moving the trolley frame. Connecting the trolley cylinder between the cross beam and the trolley subframe benefits the reguired installation length of the trolley cylinder to move the trolley frame along the cross beam.

In an embodiment the hoisting device comprises a trolley cable that is connected between the trolley frame and the trolley subframe and that comprises a reeving between the trolley frame and the trolley subframe that determines the fixed mutual displacement ratio of the trolley frame and the trolley subframe. The cable provides a simple and robust connection between the trolley frame and the trolley subframe.

In an embodiment the cross beam is hingeably connected to the legs and is hingeable with respect to the legs around a horizontally extending second hinge axis that extends substantially parallel to the first hinge axis, and wherein the hoisting device comprises an angle adjuster that 1s connected to the cross beam for adjusting the angle of the cross beam with respect to the legs.

The main hoisting force exerted on the cross beam is constant in a downward direction. By keeping the orientation of the cross beam constant, the loads experienced by the cross beam are similar in all positions of the hoisting device. The hinged connections between the cross beam and the legs ensure that hardly any moment of force is transferred from the cross beam to the legs in the plane transverse to second hinge axis. As a result the loads on the cross beam and the legs can be determined more accurately and they can be dimensioned more accurately whereby they can be lighter and more slender. Due to the constant orientation of the cross beam the trolley frame, the trolley subframe and other equipment on the cross beam is subject to more uniform and unidirectional loads. The equipment can therefore be dimensioned lighter and smaller. The uniform and unidirectional loads can be especially advantageous for moving and rotating equipment as this equipment will wear and tear less under such loads.

The various aspects and features described and shown in the specification can be applied, individually, wherever possible. These individual aspects, in particular the aspects and features described in the attached dependent claims, can be made subject of divisional patent applications.

BRIEF DESCRIPTION OF THE DRAWINGS The invention will be elucidated on the basis of an exemplary embodiment shown in the attached drawings, in which: Figure 1 is an isometric rear view of a vessel with a hoisting device according to an embodiment of the invention; Figures 2A and 2B are an isometric rear view and a side view of the hoisting device as shown in figure 1; and Figures 3A-3C are an isometric rear view, an isometric front view and a side view of the top side of the hoisting device as shown in figures 1, 2A and 2B.

DETAILED DESCRIPTION OF THE INVENTION Figure 1 shows a vessel 1 with a hoisting device according to an embodiment of the invention. The vessel 20 1 is in this embodiment configured for handling submarine cables at sea 200. The vessel 1 comprises a hull 2 with a bow 3, a stern 4, a port side 5 and a starboard side 6. The vessel 1 comprises a main cabin 7 at the bow 3, a stern chute 10 for guiding the submarine cables, a large deck 8 between the main cabin 7 and the stern chute 10, a hoisting winch 9 on the deck 8, and the hoisting device 20 at the stern chute 10 for hoisting a cable and/or a tool 201 above the deck 8 and beyond the stern chute 10. As best shown in figures 2A and ZB the hoisting device 20 comprises a first leg 21 on the port side 5, a second leg 22 on the starboard side 6 and a cross beam 40 between the first leg 21 and the second leg 22 to form a hoisting frame or A-frame. The first and second legs 21, 22 both comprise a steel rectangular box girder 24 that merges at the side of the deck 8 into a steel bottom hinge plate 25 and that merges at the side of the cross beam 40 into a steel top hinge plate 26, The first and second legs 21, 22 comprise hinge lugs 27 against the side of the box girders 24 that face the bow 3.

The hoisting device 20 comprises a first deck support 61 that is mounted to the deck 8 at the port side of the stern chute 10, and a second deck support 62 that is mounted to the deck 8 at the starboard side of the stern chute 10. The first deck support 61 and the second deck support 62 both comprise a steel frame 63 having rear hinge lugs 64, central hinge lugs 65 and front hinge lugs 66. The bottom hinge plates 25 of the legs 21, 22 extend between the central hinge lugs 65 and are hingeably connected therewith by means of hinge pins 67 that extend through pin holes in the bottom hinge plates 25 and the central hinge lugs 65. The legs 21, 22 are thereby hingeable with respect to the deck supports 61, 62 around a horizontally extending first hinge axis A. The hoisting device 20 comprises a first hydraulic tilting cylinder 71 and a second hydraulic tilting cylinder 72 that are connected with the hinge lugs 27 of the respective legs 21, 22 and the front hinge lugs 66 of the deck supports 61, 62. The tilting cylinders 71, 72 power the hinging movement in a direction T around the first hinge axis A between a retracted position in which the cross beam 40 extends above the deck 8, and an extended position in which the cross beam 40 extends beyond the deck 8 and the stern chute 4 above the sea 200.

The cross beam 40 comprises a steel rectangular box girder 41, and first central hinge lugs 42 and second central hinge lugs 44 that project downwards {from the respective ends of the box girder 41 near the legs 21, 22.

The cross beam 40 comprises first rear hinge lugs 43 and second rear hinge lugs 45 that are longer than the first and second central hinge lugs 42, 44 and that project downwards and rearwards from the stern side of the box girder 41, wherein the distal ends extend at about the same vertical height as the central hinge lugs 42, 44 of the cross beam 40. The top hinge plates 26 of the legs 21, 22 extend between the central hinge lugs 42, 44 of the cross beam 40 and are hingeably connected therewith by means of hinge pins 46 that extend through pin holes in the top hinge plates 26 and the central hinge lugs 42, 44 of the cross beam 40. The cross beam 40 is thereby hingeable with respect to the legs 21, 22 around a horizontally extending second hinge axis B that is substantially parallel to the first hinge axis A. The hoisting device 20 comprises an angle adjuster 30 that adjusts the angle between the cross beam 40 and the legs 21, 22 while the legs 21, 22 hinge in direction T around the first hinge axis A. In this example the angle adjuster 30 comprises a first parallel stabilizing rod 31 that is hingeably connected between the first rear hinge lugs 43 of the cross beam 40 and the rear hinge lugs 64 of the first deck support 61 by means of hinge pins 33, 34. The hoisting device 20 comprises a second parallel stabilizing rod 32 that is hingeably connected between the second rear hinge lugs 45 of the cross beam 40 and the second hinge lugs 64 of the second deck support 62 by means of hinge pins 33, 34. The first parallel stabilizing rod 31 and the first leg 21, and the second parallel stabilizing rod 32 and the second leg 22 form two respective parallel mechanisms that keep the cross beam 40 in the same orientation with respect to the deck 8 while the legs 21, 22 hinge in direction T around the first hinge axis A.

The angle adjuster 30 may have an alternative embodiment to adjust the angle between the cross beam 40 and the legs 21, 22 while the legs 21, 22 hinge in direction T around the first hinge axis A. Some alternative embodiments of the angle adjuster 30 are described below. These alternative embodiments are not shown in the drawings. An alternative embodiment comprises a balance beam that is attached transvers to the cross beam 40, and two cables, one between each end of the balance beam and to one of the deck supports 61, 62. A further alternative embodiment comprises a first gear wheel attached to one of the supports 61, 62, a second gear wheel attached to the cross beam 40 and a gear shaft that connects the first gear wheel and the second gear wheel. A further alternative embodiment comprises a first chain sprocket attached to one of the supports 61, 62, a second chain sprocket attached to the cross beam 40 and a chain that connects the first chain sprocket and the second chain sprocket. A further alternative embodiment comprises a first stabilizing sheave attached to one of the supports 61, 62, a second stabilizing sheave attached to the cross beam 40 and a cable that connects the first stabilizing sheave and the second stabilizing sheave. A further alternative embodiment comprises a stabilizing actuator such as a hydraulic cylinder that is attached between the cross beam 40 and one of the legs 21, 22 and that is configured to control the orientation of the cross beam 40 with respect to the legs 21, 22.

As the angle adjuster 30 keeps the orientation of the cross beam 40 constant and the main hoisting force exerted thereon is constant in a downward direction, the loads experienced by the cross beam 40 are similar in all positions of the hoisting device 20. The hinged connections between the cross beam 40 and the legs 21, 22 ensure that hardly any moment of force is transferred from the cross beam 40 to the legs 21, 22 in the plane transverse to the second hinge axis B. As a result the loads on the cross beam 40 and the legs 21, 22 can be determined more accurately and they can be dimensioned more accurately whereby they can be lighter and more slender. Due to the constant orientation of the cross beam 40 the equipment mounted thereto is subject to more uniform and unidirectional loads. The equipment can therefore be dimensioned lighter and smaller. The uniform and unidirectional loads are especially advantageous for moving and rotating equipment as this equipment will wear and tear less under such loads. As best shown in figures 3A-3C, the hoisting device 20 comprises a trolley frame 80 that is supported by the cross beam 40, that surrounds the cross beam 40 around the longitudinal axis thereof and that is linearly movable by sliding along the cross beam 40 in direction Q by means of not shown slides. The trolley frame 80 comprises a top truss 81 on top of the cross beam 40, two side trusses 82 that extend downwards from the top truss 81 at the opposite longitudinal sides of the cross beam 40, and a bottom truss 83 that extends between the side trusses 52 below the cross beam 40. The trolley frame 80 comprises bottom hinge lugs 84 at the bottom truss 83.

The hoisting device 20 comprises a trolley subframe 101 that is supported by the cross beam 40 and that is linearly movable by sliding along the cross beam 40 with respect to the cross beam 40 and the trolley frame 80. The trolley subframe 101 is a longitudinal flat open frame that has substantially the same width as the cross beam 40 and that is located partly below the top truss 81 and between the side trusses 82 of the trolley frame 80. The trolley subframe 101 comprises in this example two trolley sheaves 103 that are attached within the open trolley subframe 101 and that are rotatable in a common plane that is orientated parallel with respect to the top surface of the cross beam 40.

The hoisting device 20 comprises two opposite tensioned trolley cables 105 that are connected to the ends of the cross beam 40 and, via the trolley sheaves 103, to the top truss 81 of the trolley frame 80. The trolley cables 105 are configured symmetrical to each other with respect to the trolley subframe 101. Each trolley cable 105 runs from one end of the cross beam 40 along the top surface of the cross beam 40. Each of the respective trolley sheaves 103 in the trolley subframe 101 guides the trolley cable 105 over 180 degrees back to the top truss

81. By this configuration the trolley frame 80 is forced to move with the trolley subframe 101 when the trolley subframe 101 moves along the cross beam 40. Due to the reeving of the trolley cable 105 the displacement of the trolley frame 80 and the displacement of the trolley subframe 101 have a fixed mutual displacement ratio. In this example the displacement ratio is 2:1, the displacement of the trolley frame 80 is twice that of the displacement of the trolley subframe 101 with respect to the cross beam 40. In a not shown alternative embodiment the fixed mutual displacement ratio of the trolley frame 80 and the trolley subframe 101 with respect to the cross beam 40 is determined by a rack and pinion system. A first toothed rack is attached to the trolley frame 80 and a second toothed rack is attached to the cross beam 40. The trolley subframe 101 rotatably supports a pinion between the first and second toothed rack. When the trolley subframe 101 moves the pinion moves and therewith the trolley frame 80 moves twice the distance of the trolley subframe 101.

The hoisting device 20 comprises a trolley cylinder 104 that is connected between the cross beam 40 and one end of the trolley subframe 101. The trolley cylinder 104 is configured to move the trolley subframe 101 along the cross beam 40 in direction Q. As a result of the fixed mutual displacement ratio of the trolley frame 80 and the trolley subframe 101 the trolley cylinder 104 moves the trolley frame 80 twice the distance along the cross beam

40. This configuration benefits the required installation length of the trolley cylinder 104. The trolley cylinder 104 may also be connected between the cross beam 40 and the trolley frame 80. This configuration doubles the required installation length and halves the required power of the trolley cylinder 104, The hoisting device 20 comprises a sheave bracket 90 that has first sheave bracket hinge plates 91 that extend between the bottom hinge lugs 84 of the trolley frame 80 and that are hingeably connected therewith by means of hinge pins 92 that extend through pin holes in the first sheave bracket hinge plates 91 and the bottom hinge lugs 84. The sheave bracket 90 is thereby hingeable with respect to the trolley frame 80 around a horizontally extending third hinge axis C that is orientated transverse to the second hinge axis B.

The sheave bracket 90 furthermore comprises two second sheave bracket hinge plates 93 that are orientated transverse to the first sheave bracket hinge plates 91. As best shown in figure 3A, in this example, the tool 201 or snugger is attached to the sheave bracket 90 of the hoisting device 20. The tool 201 comprises a first box segment 202 that has at one end two first tool hinge plates 203 that are hingeably connected to the respective second sheave bracket hinge plates 93 by means of hinge pins 95 that extend through pin holes in the second sheave bracket hinge plates 93 and the first tool hinge plates 203. The tool 201 is thereby hingeable with respect to the sheave bracket 90 around a horizontally extending fourth hinge axis D that is orientated transverse to the third hinge axis C.

The tool 201 furthermore comprises a second box segment 204 that is slidably attached inside the first box segment 202 and that protrudes therefrom at the end opposite to the first tool hinge plates 203. The second box segment 204 1s slidable with respect to the first box segment 202 in the longitudinal direction of the tool 201. The second box segment 204 comprises at the end opposite to the first box segment 202 two second tool hinge plates 205 that are orientated transverse to the first tool hinge plates 203. The tool 201 comprises a ring shaped catcher 206 having a collar 207 and two catcher hinge plates 208 that are hingeably connected to the respective second tool hinge plates 205 by means of hinge pins 209 that extend through pin holes in the second tool hinge plates 205 and the catcher hinge plates 208. The catcher 206 1s thereby hingeable with respect to the second box segment 204 around a horizontally extending fifth hinge axis E that is orientated transverse to the fourth hinge axis D.

The hoisting device 20 comprises third hydraulic tilting cylinders 94 that are connected between the side truss 82 at the stern side of the cross beam 40 and one of the first sheave bracket hinge plates 91. The third tilting cylinders 94 power and/or dampen the hinging movement of the sheave bracket 90 around the third hinge axis C.

The hoisting device 20 comprises a fourth hydraulic tilting cylinder 96 that is connected between the sheave bracket 90 and the first box segment 202 of the tool

201. The fourth tilting cylinder 94 powers and/or dampens the hinging movement of the tool 201 around the fourth hinge axis D.

The tool 201 comprises hydraulic translation cylinders 210 that are connected between the first box segment 202 and the second box segment 204 of the tool 201. The translation cylinders 210 power and/or dampen the sliding movement of the second box segment 204 with respect to the first box segment 202 in the longitudinal direction of the tool 201.

The tool 201 comprises fifth hydraulic tilting cylinders 211 that are connected between the second box section 204 and the collar 207 of the catcher 206. The fifth tilting cylinders 211 power and/or dampen the hinging movement of the catcher 206 around the fifth hinge axis E.

The hoisting device 20 comprises multiple guide sheaves 111, 112, 113, 114, 115, 116, 117 that guide a hoisting cable 110 from near the first hinge axis A, along the second leg 22 and the cross beam 40 to the trolley frame 80. In this example the hoisting cable 110 originates from the hoisting winch 9 on the deck 8 and is guided through the catcher 206 of the tool 201 below the trolley frame 80. The hoisting cable 110 is suspended below the cross beam 40 as a single hoisting cable 110 with a hook at its end. The advantage of a single hoisting cable 110 is that it is easier to handle, easier to pass through the tool 201 compared to reeved in hoisting cables with a hoisting block. A single hoisting cable 110 does not twist together like the multiple reeved in hoisting cables. The configuration of the guide sheaves is explained in more detail below. A first guide sheave 111 is rotatably connected to the second leg 22 near the bottom hinge plate 25 thereof near the first hinge axis A, and a second guide sheave 112 is rotatably connected to the cross beam 40 at the end near the second leg 22 near the second hinge axis B. The first guide sheave 111 and the second guide sheave 112 are «rotatable in a common vertical plane wherein the hoisting cable 110 is guided by the first and second guide sheave 111, 112 from near the deck 8, along the second leg 22, to the top of the cross beam 40. A third guide sheave 113 is rotatably connected to the top of the cross beam 40 near the second guide sheave 112, a fourth guide sheave 114 is rotatably connected to the trolley subframe 101 near the end thereof close to the first leg 21, and a fifth guide sheave 115 is rotatably connected to the trolley frame 80 near the center thereof. The third and fourth guide sheave 113, 114 are rotatable in a common horizontal plane. The hoisting cable 110 is guided from the second guide sheave 112, via the third guide sheave 113, along the cross beam 40, via the fourth guide sheave 114 back along the cross beam 40 to the fifth guide sheave 115. A damper 106 is connected between the trolley sub frame 101 and the fourth guide sheave 114 to dampen abrupt loads on the hoisting cable 110. As best shown in figure 3B a sixth guide sheave 116 is rotatably connected to the trolley frame 80 and a seventh guide sheave 117 is rotatably connected to the sheave bracket 90 below the bottom of the trolley frame 80. The sixth and seventh guide sheaves 116, 117 are rotatable in a common vertical plane. The hoisting cable 110 is guided from the fifth guide sheave 115, via the sixth guide sheave 116, via the seventh guide sheaves 117 to the tool

201. The hoisting cable 110 passes from the seventh guide sheave 117 through a not shown internal passage of the first box segment 202 and the second box segment 204 through the ring shaped catcher 206. As the fourth guide sheave 114 and the fifth guide sheave 115 are respectively connected to the trolley subframe 101 and the trolley frame 80 they are movable with respect to each other and with respect to the third guide sheave 113 that is connected to the cross beam 40. When the trolley subframe 101 is actuated by the trolley cylinder 104 the displacement of the fifth guide sheave 115 is twice that of the displacement of the fourth guide sheave 114 with respect to the third guide sheave 113. The reeving of the hoisting cable 110 around the third, fourth and fifth guide sheaves 113, 114, 115 compensates for the difference in their relative displacement.

As a result the hoisting cable 110 will not move with respect to the trolley frame 80 when the trolley subframe 101, and therewith the trolley frame 80, moves along the cross beam 40. The hoisting cable 110 will have a constant length L suspended below the cross beam 40, in this example below the tool 201. The single hoisting cable 110, as opposed to multiple reeved in hoisting cables with a hoisting block, is easy to handle, easy to pass through the tool 201 and does not twist together.

It is to be understood that the above description is included to illustrate the operation of the preferred embodiments and is not meant to limit the scope of the invention.

From the above discussion, many variations will be apparent to one skilled in the art that would yet be encompassed by the scope of the present invention.

Claims

CONCLUSIONS

A vessel with a hoisting device, the vessel comprising a hull with a deck and the hoisting device comprising two hull supports, two legs pivotally connected at one end to one of the supports, a cross beam supported by the hull. legs at their opposite ends and spaced from the deck, and a hoisting rope suspended from the cross beam, the legs being pivotable about a horizontally extending first pivot axis between a retracted position in which the cross beam extends above the deck, and an extended position in which the crossbar extends beyond the deck, the crossbar being pivotally connected to the legs and pivotable relative to the legs about a horizontally extending second pivot axis extending substantially parallel to the first pivot axis, and wherein the hoist comprises an angle adjuster connected to the crossbar for adjusting the angle of the crossbar in relation to the legs.

The vessel of claim 1, wherein the angle adjuster maintains the transom substantially in the same orientation relative to the deck as the legs pivot about the first pivot axis.

The vessel of claim 1 or 2, wherein the angle adjuster comprises a stabilizing bar extending generally along and spaced from the legs and pivotally connected to the crossbar and one of the struts.

The vessel of claim 3, wherein the hoisting device comprises a stabilizing bar at each leg.

Craft according to any of the preceding claims, wherein the hoisting device comprises a hydraulic cylinder connected between one of the legs and one of the supports for moving the legs between the retracted position and the extended position.

Vessel according to any of the preceding claims, wherein the hoisting cable is guided from near the first pivot axis to the cross beam.

Vessel according to any of the preceding claims, wherein the hoisting cable is guided from near the first pivot axis to the cross beam along one of the legs.

Vessel according to any one of the preceding claims, wherein the hoisting device comprises a trolley frame supported by and movable along the cross beam, and wherein the hoisting cable is suspended from the cross beam by means of the trolley frame.

The vessel of claim 8, wherein the hoisting device comprises a trolley subframe movable along the cross beam, the trolley subframe and the trolley frame being arranged to have a fixed relative displacement relationship with respect to the cross beam, the hoisting cable being guided from the cross beam via the trolley subframe to the trolley frame and comprises a reeving between the trolley frame and the trolley subframe that compensates for the fixed relative displacement ratio such that the hoist cable has a constant length hanging below the crossbar as the trolley frame moves along the crossbar.

The vessel of claim 9, wherein the trolley frame and trolley subframe are movable along the cross beam in the same direction.

A vessel according to claim 9 or 10, wherein the hoisting device comprises a hydraulic trolley cylinder connected between the cross beam and the trolley subframe for moving the trolley frame along the cross beam.

Vessel according to any one of claims 9-11, wherein the hoisting device comprises a trolley cable connected between the trolley frame and the trolley subframe and which comprises a reeving between the trolley frame and the trolley subframe that defines the fixed relative displacement ratio of the trolley frame and the trolley subframe. .

A vessel according to any one of claims 9-12, wherein the fixed relative displacement ratio of the trolley frame and the trolley subframe is 2: 1.

14. Vessel with a hoisting device, the vessel comprising a hull with a deck and the hoisting device comprising two supports attached to the hull, two legs pivotally connected at one end to one of the supports, a cross beam supported by the legs at their opposite ends and spaced from the deck, and a hoisting rope suspended from the cross beam, the legs being pivotable about a horizontally extending first pivot axis between a retracted position in which the cross beam extends above the deck, and an extended position in which the cross beam extends beyond the deck, the hoist comprising a trolley frame supported by and movable relative to the cross beam and a trolley subframe movable along the cross beam, the trolley subframe and the trolley frame being arranged to to have a fixed relative displacement ratio with respect to the cross beam, and where the h ice rope is routed from the crossbar through the trolley subframe to the trolley frame and includes a reeving between the trolley frame and the trolley subframe that compensates for the fixed relative displacement ratio such that the hoist rope has a constant length hanging below the crossbar as the trolley frame moves along the crossbar.

The vessel of claim 14, wherein the trolley frame and the Lrolley subframe are movable along the cross beam in the same direction.

Vessel according to claim 14 or 15, wherein the fixed mutual displacement ratio of the trolley frame and the trolley subframe is 2: 1.

17. Vessel according to any one of claims 14-16,

wherein the hoisting cable is guided from near the first pivot axis to the cross beam.

A vessel according to any one of claims 14-17, wherein the hoisting cable is guided from near the first pivot axis to the cross beam along one of the legs.

A vessel according to any one of claims 14-18, wherein the hoisting device comprises a hydraulic trolley cylinder connected between the crossbar and the trolley subframe for moving the trolley frame along the crossbar.

A vessel according to any one of claims 14-19, wherein the hoisting device comprises a trolley cable connected between the trolley frame and the trolley subframe and comprising a reeving between the trolley frame and the trolley subframe defining the fixed relative displacement ratio of the trolley frame and the trolley subframe. .

A vessel according to any one of claims 14-20, wherein the crossbar is pivotally connected to the legs and is pivotable relative to the legs about a horizontally extending second pivot axis extending substantially parallel to the first pivot axis, and wherein the hoisting device includes an angle adjuster connected to the crossbar for adjusting the angle of the crossbar with respect to the legs.

The craft of claim 21, wherein the angle adjuster maintains the transom substantially in the same orientation with respect to the deck while the legs are pivoted about the first pivot axis.

A vessel according to claim 21 or 22, wherein the angle adjuster comprises a stabilizer bar extending substantially along and spaced from the legs and which is pivotally connected to the crossbar and one of the struts.

The craft of claim 23, wherein the hoist comprises a stabilizing bar at each leg,

25. Vessel according to any of claims 14-24,

wherein the hoisting device comprises a hydraulic cylinder connected between one of the legs and one of the supports for moving the legs between the retracted position and the extended position. -O0-0-0-0-0-0-0-0-