VESSEL WITH HEAVE COMPENSATION SYSTEM

Description

BACKGROUND

[0001] The invention relates to a vessel comprising a hull and a heave compensation system for a load that is suspended from the hull.

[0002] Vessels may be provided with a heave compensation system to keep a suspended load at a constant height while the hull is subject to heave. A known heave compensation system comprises a winch with a drum and a hoisting cable around the drum for hoisting and suspending the load. The heave, roll and pitch motions of the hull are detected and continuously compensated by corresponding counter-rotation of the drum. The rotation of the drum may be powered by a hydraulic motor. The drum may be subject to a high static torque, especially when the load is hoisted out of the water. Therefore a strong hydraulic motor is needed, having a relatively high hydraulic fluid displacement per rotation to deliver that torque. It would require a high fluid flow to drive that motor during heave compensation. In a submerged condition the weight of the load is reduced, resulting in a much lower torque requirement of the drum and consequently much lower fluid displacement per rotation of the motor. Attempts have been made to compensate this, for example by using reduction boxes with multiple gears or by using over-dimensioned or high performance hydraulic power packs, which are both not preferred.

[0003] WO2009038468 and WO2008022125 relate to heave compensating systems which employ winches to compensate the motions of the hull with respect to the suspended load.

[0004] It is an object of the present invention to provide a vessel with a heave compensation system having a winch that can deliver a high static torque in combination with a quick dynamic response during heave compensation.

[0005] It is an object of the present invention to provide a vessel with a heave compensation system having a winch that is rotated by a hydraulic driving system with an efficient use of the hydraulic driving components.

SUMMARY OF THE INVENTION

[0006] According to a first aspect the invention provides a vessel comprising a hull and a heave compensation system for a load that is suspended from the hull, wherein the heave compensation system comprises a winch with a drum on the hull and a hoisting cable around the drum for hoisting and suspending the load, a first hydraulic motor and a second hydraulic motor that are operatively connected to the drum to rotate synchronously with the drum, wherein the hydraulic motors each have a first hydraulic fluid port and a second hydraulic fluid port to drive the hydraulic motors and the winch in the two opposite rotation directions depending on the port into which the hydraulic fluid is fed, and a hydraulic drive system with a hydraulic circuit to control the hydraulic fluid through the first ports and second ports of the hydraulic motors, wherein the hydraulic drive system comprises a powered hydraulic fluid source to provide hydraulic fluid under pressure, a first hydraulic accumulator assembly to store and bias hydraulic fluid, a first valve assembly in a hydraulic fluid connection between the hydraulic fluid source and the ports of the hydraulic motors, a second valve assembly in a hydraulic fluid connection between the first valve assembly and the first port of the second hydraulic motor, and a third valve assembly in a hydraulic fluid connection between the first accumulator assembly and the first port of the second hydraulic motor, wherein the hydraulic drive system is able to switch between a hoisting mode and a heave compensation mode by means of the second valve assembly and the third valve assembly, wherein in the hoisting mode the hydraulic fluid from the first valve assembly is fed parallel into both first ports of the hydraulic motors or parallel into both second ports of the hydraulic motors to drive the rotation of the winch in one of the opposite rotation directions, and wherein in the heave compensation mode the hydraulic fluid from the first valve assembly is fed into the first port of the first hydraulic motor or into the second port of the first hydraulic motor to drive the rotation of the winch in one of the rotation directions, and the first hydraulic accumulator assembly biases the hydraulic fluid to the first port of the second hydraulic motor.

[0007] The vessel is provided with a heave compensation system having a winch with a drum that is operatively connected to two hydraulic motors. In the hoisting mode the full load may be hoisted above the water. In this mode the two hydraulic motors are employed in parallel, whereby a high static torque is delivered to carry the load. At the given capacity of the hydraulic fluid source the delivery of this high torque is detrimental to the rotation speed of the winch. This low rotation speed allows a good control over the hoisting process. When the load is brought under water to be kept at a constant height, the hydraulic drive system is switched over to the heave compensation mode by alternating the opposite settings of the second valve assembly and the third valve assembly. In the heave compensation mode the second hydraulic motor is not powered anymore by the first valve assembly but it is connected to the biased first hydraulic accumulator assembly. Depending on the rotation direction the second hydraulic motor alternately acts as a hydraulic motor or as a hydraulic pump. The second hydraulic motor delivers substantially the entire static torque while the much lower dynamic torque is delivered by the first hydraulic motor. At the same given capacity of the hydraulic fluid source the first hydraulic motor is then able to quickly respond with a rotation speed that is much higher than in the hoist mode. In the system according to the invention the two hydraulic motors are in both modes both employed, which is efficient.

[0008] In an embodiment the first hydraulic motor is a variable displacement hydraulic motor that can change between a high fluid displacement mode, in which a first torque is delivered using a first amount of hydraulic fluid per rotation, and a low fluid displacement mode in which a lower second torque is delivered using a lower second amount of hydraulic fluid per rotation, wherein in the hoisting mode the first hydraulic motor is in the high displacement mode and wherein in the heave compensation mode the first hydraulic motor is in the low displacement mode. By setting the first hydraulic motor into the low displacement mode the rotation speed is increased for the given capacity of the hydraulic fluid source. This enhances the dynamic response of the winch. In the hoisting mode the first hydraulic motor is set in the high displacement mode to deliver the maximal static torque.

[0009] In an embodiment the first hydraulic motor is a dual displacement hydraulic motor that can switch between the high displacement mode and the low displacement mode.

[0010] In an embodiment the first hydraulic motor is a radial piston hydraulic motor in which the number of active radial pistons is adjustable.

[0011] In an embodiment the second hydraulic motor is a radial piston hydraulic motor.

[0012] Radial piston hydraulic motors are able to deliver a high torque without internal reduction gears. This makes the motors compact and reliable.

[0013] In an embodiment the second hydraulic motor delivers the same first torque using the same first amount of hydraulic fluid per rotation as the first hydraulic motor in its high fluid displacement mode, whereby the motors are in balance when the high static torque in the hoisting mode is delivered.

[0014] In an embodiment the hydraulic drive system comprises a fourth valve assembly between the hydraulic fluid source and the first hydraulic accumulator assembly to fill, refill or bias the first hydraulic accumulator assembly. In the hoisting mode the first hydraulic accumulator may be prepared for the heave compensation by bringing the hydraulic fluid to the desired pressure by means of the fourth valve assembly. The system can then quickly switch over to the heave compensation mode.

[0015] In an embodiment the hydraulic drive system comprises a second hydraulic accumulator assembly to store and bias hydraulic fluid, a fifth valve assembly in a hydraulic fluid connection between the first valve assembly and the second port of the second hydraulic motor, and a sixth valve assembly between the second hydraulic accumulator assembly and the second port of the second hydraulic motor, wherein the second hydraulic accumulator assembly biases the hydraulic fluid to the second port of the second hydraulic motor. The second hydraulic accumulator assembly ensures that the second hydraulic motor is continuously provided with sufficient hydraulic fluid when it is imposed to act as a hydraulic pump.

[0016] In an embodiment thereof the hydraulic drive system comprises a seventh valve assembly between the hydraulic fluid source and the second hydraulic accumulator assembly to fill, refill and bias the second hydraulic accumulator assembly. The seventh valve assembly can be used for the same purposes as the fourth valve assembly.

[0017] In an embodiment the pressure of the hydraulic fluid in the biased first hydraulic accumulator assembly is higher than the pressure of the hydraulic fluid in the biased second hydraulic accumulator assembly, whereby the static torque is delivered by the pressure difference.

[0018] In an embodiment the first hydraulic accumulator assembly, and the second accumulator assembly when present, is a free piston accumulator comprising a cylinder with a port for passage of the hydraulic fluid and a piston that is slidable through the cylinder to bias the hydraulic fluid to the port.

[0019] In an embodiment the free piston accumulator comprises a biased or pressurized volume of gas that is separated from the hydraulic fluid by the piston. The gas may by nitrogen. The amount of gas and thereby the provided bias may be adjusted to the load.

[0020] In an embodiment the hydraulic drive system comprises a displacement sensor to determine the position of the piston in its sliding direction. With this the piston can be set halfway the cylinder to allow strokes in both directions during heave compensation. The setting may be performed by means of the fourth valve assembly and seventh valve assembly when present.

[0021] In an embodiment the first valve assembly comprises a bidirectional, proportional valve to control the winch during hoisting above the water, or above a working platform of the vessel.

[0022] In an embodiment the heave compensation system comprises a brake for the drum to be activated during switching between the hoisting mode and the heave compensation mode.

[0023] In an embodiment the hydraulic drive system comprises a controller that is operatively connected with the first valve assembly to control the first valve assembly in response to heave, roll and pitch parameters of the hull with respect to a reference height for the load.

[0024] In an embodiment the vessel is configured as a water injection dredging vessel, wherein the load is a jet bar that is provided with a series of water jet nozzles, wherein the jet bar is under water suspended from the hull.

[0025] According to a second aspect, the invention provides a method for suspending a load from a vessel, wherein the vessel comprises a hull and a heave compensation system for the load that is suspended from the hull of the vessel, wherein the heave compensation system comprises a winch with a drum on the hull and a hoisting cable around the drum for hoisting and suspending the load, a first hydraulic motor and a second hydraulic motor that are operatively connected to the drum to rotate synchronously with the drum, and a hydraulic drive system with a hydraulic circuit to control the hydraulic fluid through the hydraulic motors, wherein the hydraulic drive system comprises a powered hydraulic fluid source to provide hydraulic fluid under pressure and a first hydraulic accumulator assembly to store and bias hydraulic fluid, wherein the method comprises switching the hydraulic drive between a hoisting mode and a heave compensation mode during hoisting the load, wherein in the hoisting mode the hydraulic fluid from the hydraulic fluid source is fed parallel through both the first hydraulic motor and the second hydraulic motor to drive the rotation of the winch in one of the opposite rotation directions, and wherein in the heave compensation mode the hydraulic fluid from the hydraulic fluid source is fed through the first hydraulic motor while the first hydraulic accumulator assembly is in fluid connection with the second hydraulic motor and delivers hydraulic fluid to or receives hydraulic fluid from the second hydraulic motor depending on the rotation direction of the first hydraulic motor.

[0026] In an embodiment thereof the hydraulic drive system is in the hoisting mode when the load is above the water line and wherein the hydraulic drive is switched between the hoisting mode and the heave compensation mode when the load is submerged in the water.

[0027] 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

[0028] The invention will be elucidated on the basis of an exemplary embodiment shown in the attached drawings, in which:

Figures 1A and 2B a dredging vessel with a heave compensation system according to the invention;

Figure 2 the hydraulics of the heave compensation system of the vessel according to figures 1A and 1B;

Figures 3A and 3B the active components of the hydraulics when the heave compensation system is in the hoisting mode; and

Figures 4A and 4B the active components of the hydraulics when the heave compensation system is in the heave compensation mode.

DETAILED DESCRIPTION OF THE INVENTION

[0029] Figures 1A and 1B show a dredging vessel 1 that is configured for water injection dredging of a sea bed 10. Water injection dredging is applied to sea beds having a fluidisable top layer or sediment. The method is applied to make trenches for under water infrastructures in the sea bed 10 or for maintenance dredging of the sea bed 10 at shipping areas. The fluidized top layer may be transported by a natural, predictable water flow, such as a tidal flow or a river flow.

[0030] The dredging vessel 1 comprises a floating hull 5 with a bow 6, a stern 7, and a working platform 8 and propulsion 9 at the backside. On the platform 8 two supports 15 are provided. The supports 15 are provided with guide pulleys 22 and they also form the rotary bearings of an A-frame 16. The A-frame 16 is provided with hoisting pulleys 20 at the starboard side and the port side. The A-frame 16 can pivot in direction A with respect to the working platform 8 to move the hoisting pulleys 20 between a position above the platform 8 and a position behind the stern 13. Two hoisting cables 21 run via the hoisting pulleys 20 and the guide pulleys 22 to two hydraulically powered winches 31 on the platform 8.

[0031] The hoisting cables 21 carry a horizontally extending jet bar 25 that is provided with a series of jet nozzles 26 that are directed in downward and backward direction B. The jet bar 25 is fed with pressurized water while suspended on the hoisting cables 21. During injection dredging the dredging vessel 1 moves at a constant speed in its forward shipping direction C. In order to obtain a constant depth of the sea bed 10 by the injection dredging, the jet bar 25 needs to pass at a constant height with respect to the water line. During the dredging the hull 5 is suspended is subjected to heave, making pitching and rolling movements. This is actively compensated by controlling the rotary motion of each of the two winches 31 by means of a hydraulic heave compensation system 30 according to the invention.

[0032] The hydraulic layout of the heave compensation system 30 is shown in figure 2. The system 30 comprises a first hydraulic motor 33, a second hydraulic motor 34 and a brake 37 that are connected in parallel to the drive shaft 35 of the winch 31, wherein the hydraulic motors 33, 34 are located on opposite sides of the drum 36. The hydraulic motors 33, 34 are radial piston hydraulic motors that are directly connected to the drive shaft 35, that is, without reducing gears in between. The hydraulic motors 33, 34 deliver a specific torque of more than 200 Nm/bar with a displacement of more than 10000 cm³ per rotation. The typical maximum operating pressure is 300 bar.

[0033] The first hydraulic motor 33 is a variable displacement hydraulic motor. This motor 33 can change between a high fluid displacement mode, in which a high torque is delivered using a large amount of hydraulic fluid per rotation, and a low fluid displacement mode in which a lower torque is delivered using a lower amount of hydraulic fluid per rotation. In the low fluid displacement mode the motor 33 delivers more rotations at the same hydraulic fluid displacement. The variable displacement is embodied by setting the number of active radial pistons. In particular, it is a dual displacement motor using two groups of radial pistons of which one is selectively powered. The second hydraulic motor 34 is a regular radial piston hydraulic motor having specifications that are equal to the specifications of the first hydraulic motor 33 in its high fluid displacement mode. The hydraulic motors 33, 34 can work reversely as a hydraulic fluid pump when a rotation is imposed.

[0034] The system 30 comprises a first hydraulic pump 41, a second hydraulic pump 42, a first bidirectional, proportional valve 51, a second bidirectional, proportional valve 52 and a third bidirectional, proportional valve 53, a first break valve 61 and a second break valve 61, a first on-off valve 71, a second on-off valve 72, a third on-off valve 73, a fourth on-off valve 74 and a fifth on-off valve 75, and a first free piston accumulator 81 and a second free piston accumulator 82.

[0035] The break valves 61, 62 can change between a check mode in which hydraulic fluid can pass in only one direction as indicated, and a throttle mode in which the passage of hydraulic fluid is throttled in a controlled manner. The mode is changed by feeding hydraulic fluid to the respective activation port.

[0036] The free piston accumulators 81, 82 each comprise a cylinder 83 and a freely slidable piston 84 inside that separates the inner space in a fluid chamber 85 that is connected to the port of the free piston accumulator 81, 82, and a gas chamber 86 that is connected to a respective external gas chamber 91, 92. The gas chambers 86, 91, 92 are filled with nitrogen under pressure. The free piston accumulators 81, 82 are each provided with a position sensor to derive the position of the pistons 84 in the longitudinal direction of the cylinders 83.

[0037] The hydraulic pumps 41, 42 deliver hydraulic fluid at a constant pressure of about 300 bar. The first hydraulic pump 41 is connected to the first proportional valve 51. The second hydraulic pump 42 is connected to the second proportional valve 52 and the third proportional valve 53. As described hereafter, the first pump 41 forms part of a hydraulic circuit that powers the rotation of the winch 31, while the second pump 42 forms part of a hydraulic circuit to bias the winch 31.

[0038] The first port of the first proportional valve 51 is hydraulically connected to the first break valve 61 and to the activation port for the check mode thereof. The connection is continued to the first port of the first hydraulic motor 33, wherein the first break valve 61 can be bypassed via the first on-off valve 71. The first port of the first proportional valve 51 is also hydraulically connected to the second break valve 62 and to the activation port for the check mode thereof. The connection is continued via the second on-off valve 72 to the first port of the second hydraulic motor 34.

[0039] The second port of the first proportional valve 51 is hydraulically connected to the pilot port or throttle activation port of the first break valve 61 and to the second port of the first hydraulic motor 33. The second port of the first proportional valve is also hydraulically connected to the pilot port or throttle activation port of the second break valve 62 and via the fourth valve 74 to the second port of the second hydraulic motor 34.

[0040] The first port of the second proportional valve 52 is hydraulically connected to the port of the first free piston accumulator 81 and via the third on-off valve 73 to the first port of the second hydraulic motor 34. The first port of the third proportional valve 53 is hydraulically connected to the port of the second free piston accumulator 82 and via the fifth on-off valve 75 to the second port of the second hydraulic motor 34.

[0041] The system 30 furthermore comprises an electric controlling circuit that is not shown. The controlling circuit is operatively connected to the proportional valves 51-53, the on-off valves 71-75, the break 37 and the position sensors of the free piston accumulators 81, 82. The electric controlling circuit comprises position sensors, and/or displacement sensors and/or accelerometers to determine the heave, roll and pitch motions of the hull 5 to be compensated. The controlling circuit may also be provided with joysticks for manual control of at least the proportional valve 51.

[0042] The system 30 is configured to operate in two modes, which are the hoisting mode and the heave compensation mode. These modes are elucidated under reference to figures 3A-3D. The system 30 can switch between the modes, wherein the brake 37 may be activated during the switching to keep the winches 31 temporary on hold.

[0043] Figures 3A and 3B show the operation in the hoisting mode. In this mode the jet bar 25 is hoisted above the platform or the water by manual use of the joysticks. In this mode the winches 31 need to deliver and control a high static torque while the rotation speed is less critical. The high torque is delivered by the two hydraulic motors 33, 34 that work parallel. In the hoisting mode the first on-off valve 71, the third on-off valve 73 and the fifth on-off valve 75 are closed, and the second on-off valve 72 and fourth on-off valve 74 are open. The first hydraulic motor 33 is set in its high fluid displacement mode. In the hoisting mode the free piston accumulators 81, 82 do not form part of the active circuit.

[0044] During hoisting as shown in figure 3A, wherein the jet bar 25 moves upward, the hydraulic fluid from the first port of the first proportional valve 51 passes the break valves 61, 62 that are in the check mode for that direction, and enter the first ports of the hydraulic motors 33, 34. The hydraulic fluid from the second ports of the hydraulic motors 33, 34 returns to the second port of the first proportional valve 51.

[0045] During paying out as shown in figure 3B, wherein the jet bar 25 moves downward, the hydraulic fluid from the second port of the first proportional valve 51 activate the throttle mode of the break valves 61, 62 via the pilot ports and enter the second ports of the hydraulic motors 33, 34. The hydraulic fluid from the first ports of the hydraulic motors 33, 34 returns to the first port of the first proportional valve 51 via the break valves 61, 62 to be throttled. Basically, the hydraulic motors 33, 34 that are subject to the high static torque act as a pump, wherein the pressurized fluid is drained off in a controlled manner.

[0046] Figures 4A and 4B show the operation in the heave compensation mode. In this mode the jet bar 25 is fully submerged in the water, resulting in about half the static weight due to partial buoyancy. In this mode the winches 31 need to deliver and control much lower static torques than in the hoisting mode, while the rotation speed is much higher to quickly respond to the dynamic motions of the hull 5. The static torque is delivered and maintained by the second hydraulic motor 34 while the rotation of the winches 31 is activated by the first hydraulic motor 33.

[0047] When the system 30 is ready to switch from the hoisting mode to the heave compensation mode, the brake 37 is temporary activated while the average position of the pistons 84 in the cylinders 83 of the free piston accumulators 81, 82 are controlled around their mid positions by activation of the second proportional valve 52 and the third proportional valve 53, respectively. The bias pressure in the first free piston accumulator 81 is much higher than the bias pressure in the second free piston accumulator 82, wherein the pressure difference is about equal to the fluid pressure as applied at the last at the first port of the second hydraulic motor 34 during submersion of the jet bar 25 in the water in the hoisting mode.

[0048] In the heave compensation mode the first on-off valve 71, the third on-off valve 73 and the fifth on-off valve 75 are open, and the second on-off valve 72 and fourth on-off valve 74 are closed. The first hydraulic motor 33 is set in its low fluid displacement mode. In the heave compensation mode the free piston accumulators 81, 82 form part of the active hydraulic circuit of the second hydraulic motor 34. The rotation of the winch 31 is activated by the first proportional valve 51, which is actively controlled by the electronic circuit in response to the heave parameters.

[0049] During downward compensation as shown in figure 4A, wherein the jet bar 25 moves upward with respect to the A-frame 16, the hydraulic fluid from the first port of the first proportional valve 51 bypasses the first break valve 61 via the first on-off valve 71 and enters the first port of the first hydraulic motor 33 only. The hydraulic fluid from the second port of the first hydraulic motor 33 returns to the second port of the first proportional valve 51. The biased hydraulic fluid from the first free piston accumulator 81 enters the first port of the second hydraulic motor 34 via the third on-off valve 73 to maintain the compensation of the static torque on the winch 31. The hydraulic fluid from the second port of the second hydraulic motor 34 is fed to the second free piston accumulator 82 via the fifth valve 75. The pistons 84 move accordingly in longitudinal directions D, E as indicated.

[0050] During upward compensation as shown in figure 4B, wherein the jet bar 25 moves downward with respect to the A-frame 16, the hydraulic fluid from the second port of the first proportional valve 51 enters the second port of the first hydraulic motor 33 only. The hydraulic fluid from the first port of the first hydraulic motor 33 returns to the second port of the first proportional valve 51 via the first on-off valve 71. The biased hydraulic fluid from the second free piston accumulator 82 enters the second port of the second hydraulic motor 34 via the fifth on-off valve 75 to ensure that the second hydraulic motor 34 remains filled with hydraulic fluid. The second hydraulic motor 34 acts as a pump. The hydraulic fluid from the first port of the second hydraulic motor 34 is fed to the first free piston accumulator 82 via the third valve 75 to maintain the compensation of the static torque on the winch 31. The pistons 84 move accordingly in longitudinal directions D, E as indicated.

[0051] In the heave compensation mode the pistons 84 move as indicated, wherein the pressure changes are limited due to the bias. That is, due to the bias the movement of the pistons 84 is not linear anymore to the pressure differences. Only the fraction of the static torque that is not compensated by the second hydraulic motor 34 due to the friction in the system and the stiffness of the gas volumes, the according pressure drop is taken by the first hydraulic motor 33. As only the first hydraulic motor 33 in its low displacement mode needs to be powered, it can respond very quickly with a rotation speed that is multiple times higher than the rotation speed in during hoisting. In this way a heave compensation system 30 is provided that can deliver high torques in its hoisting mode by powering both hydraulic motors 33, 34 in parallel, wherein the same two hydraulic motors 33, 34 are used in the heave compensation mode to carry the lower static torque on the one hand while being able to quickly respond on the other hand.

[0052] In the heave compensation mode the pistons 84 of the free piston accumulators 81, 82 are regularly brought back to their mid positions by activation of the second proportional valve 52 and the third proportional valve 53, respectively to compensate small hydraulic fluid losses inside the second hydraulic motor 34.

[0053] 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

1. Vessel (1) comprising a hull (5) and a heave compensation system (30) for a load (25) that is suspended from the hull (5), wherein the heave compensation system comprises a winch (31) with a drum (36) on the hull (5) and a hoisting cable (21) around the drum for hoisting and suspending the load, characterised a first hydraulic motor (33) and a second hydraulic motor (34) that are operatively connected to the drum (36) to rotate synchronously with the drum, wherein the hydraulic motors (33, 34) each have a first hydraulic fluid port and a second hydraulic fluid port to drive the hydraulic motors (33, 34) and the winch (31) in the two opposite rotation directions depending on the port into which the hydraulic fluid is fed, and a hydraulic drive system with a hydraulic circuit to control the hydraulic fluid through the first ports and second ports of the hydraulic motors (33, 34), wherein the hydraulic drive system comprises a powered hydraulic fluid source (41, 42) to provide hydraulic fluid under pressure, a first hydraulic accumulator assembly (81) to store and bias hydraulic fluid, a first valve assembly (51) in a hydraulic fluid connection between the hydraulic fluid source (41) and the ports of the hydraulic motors (33, 34), a second valve assembly (72) in a hydraulic fluid connection between the first valve assembly (51) and the first port of the second hydraulic motor (34), and a third valve assembly (73) in a hydraulic fluid connection between the first accumulator assembly (81) and the first port of the second hydraulic motor (34), wherein the hydraulic drive system is able to switch between a hoisting mode and a heave compensation mode by means of the second valve assembly (72) and the third valve assembly (73), wherein in the hoisting mode the hydraulic fluid from the first valve assembly (51) is fed parallel into both first ports of the hydraulic motors (33, 34) or parallel into both second ports of the hydraulic motors (33, 34) to drive the rotation of the winch (31) in one of the opposite rotation directions, and wherein in the heave compensation mode the hydraulic fluid from the first valve assembly (51) is fed into the first port of the first hydraulic motor (33) or into the second port of the first hydraulic motor (33) to drive the rotation of the winch (31) in one of the rotation directions, and the first hydraulic accumulator assembly (81) biases the hydraulic fluid to the first port of the second hydraulic motor (34).

2. Vessel (1) according to claim 1, wherein the first hydraulic motor (33) is a variable displacement hydraulic motor that can change between a high fluid displacement mode, in which a first torque is delivered using a first amount of hydraulic fluid per rotation, and a low fluid displacement mode in which a lower second torque is delivered using a lower second amount of hydraulic fluid per rotation, wherein in the hoisting mode the first hydraulic motor (33) is in the high displacement mode and wherein in the heave compensation mode the first hydraulic motor (33) is in the low displacement mode, wherein the first hydraulic motor (33) is preferably a dual displacement hydraulic motor that can switch between the high displacement mode and the low displacement mode.

3. Vessel (1) according to claim 2, wherein the first hydraulic motor (33) is a radial piston hydraulic motor in which the number of active radial pistons is adjustable.

4. Vessel (1) according to any one of the preceding claims, wherein the second hydraulic motor (34) is a radial piston hydraulic motor.

5. Vessel (1) according to claims 2 and 4, wherein the second hydraulic motor (34) delivers the same first torque using the same first amount of hydraulic fluid per rotation as the first hydraulic motor (33) in its high fluid displacement mode.

6. Vessel (1) according to any one of the preceding claims, wherein the hydraulic drive system comprises a fourth valve assembly (52) between the hydraulic fluid source (42) and the first hydraulic accumulator assembly (81) to fill, refill or bias the first hydraulic accumulator assembly (81).

7. Vessel (1) according to any one of the preceding claims, wherein the hydraulic drive system comprises a second hydraulic accumulator assembly (82) to store and bias hydraulic fluid, a fifth valve assembly (74) in a hydraulic fluid connection between the first valve assembly (51) and the second port of the second hydraulic motor (34), and a sixth valve assembly (75) between the second hydraulic accumulator assembly (82) and the second port of the second hydraulic motor (34), wherein the second hydraulic accumulator assembly (82) biases the hydraulic fluid to the second port of the second hydraulic motor (34), wherein the hydraulic drive system preferably comprises a seventh valve assembly (53) between the hydraulic fluid source (42) and the second hydraulic accumulator assembly (82) to fill, refill or bias the second hydraulic accumulator assembly (82).

8. Vessel (1) according to claim 7, wherein the pressure of the hydraulic fluid in the biased first hydraulic accumulator assembly (81) is higher than the pressure of the hydraulic fluid in the biased second hydraulic accumulator assembly (82).

9. Vessel (1) according to any one of the preceding claims, wherein the first hydraulic accumulator assembly (81), and the second accumulator assembly (82) when present, is a free piston accumulator comprising a cylinder (83) with a port for passage of the hydraulic fluid and a piston (84) that is slidable through the cylinder (83) to bias the hydraulic fluid to the port, wherein the free piston accumulator preferably comprises a biased or pressurized volume of gas (86) that is separated from the hydraulic fluid by the piston (84), wherein the hydraulic drive system preferably comprises a displacement sensor to determine the position of the piston (84) in its sliding direction.

10. Vessel (1) according to any one of the preceding claims, wherein the first valve assembly (51) comprises a bidirectional, proportional valve.

11. Vessel (1) according to any one of the preceding claims, wherein the heave compensation system (30) comprises a brake (37) for the drum to be activated during switching between the hoisting mode and the heave compensation mode.

12. Vessel (1) according to any one of the preceding claims, wherein the hydraulic drive system comprises a controller that is operatively connected with the first valve assembly (51) to control the first valve assembly in response to heave, roll and pitch parameters of the hull (5) with respect to a reference height for the load (25).

13. Vessel (1) according to any one of the preceding claims, configured as a water injection dredging vessel, wherein the load (25) is a jet bar (25) that is provided with a series of water jet nozzles (26), wherein the jet bar (25) is under water suspended from the hull (5) .

14. Method for suspending a load (25) from a vessel (1), wherein the vessel (1) comprises a hull (5) and a heave compensation system (30) for the load (25) that is suspended from the hull (5) of the vessel (1), wherein the heave compensation system (30) comprises a winch (31) with a drum (36) on the hull (5) and a hoisting cable (21) around the drum (36) for hoisting and suspending the load (25), characterised by a first hydraulic motor (33) and a second hydraulic motor (34) that are operatively connected to the drum (36) to rotate synchronously with the drum (36), and a hydraulic drive system with a hydraulic circuit to control the hydraulic fluid through the hydraulic motors (33, 34), wherein the hydraulic drive system comprises a powered hydraulic fluid source (41, 42) to provide hydraulic fluid under pressure and a first hydraulic accumulator assembly (81) to store and bias hydraulic fluid, wherein the method comprises switching the hydraulic drive between a hoisting mode and a heave compensation mode during hoisting the load (25), wherein in the hoisting mode the hydraulic fluid from the hydraulic fluid source (41) is fed parallel through both the first hydraulic motor (33) and the second hydraulic motor (34) to drive the rotation of the winch (31) in one of the opposite rotation directions, and wherein in the heave compensation mode the hydraulic fluid from the hydraulic fluid source (41) is fed through the first hydraulic motor (33) while the first hydraulic accumulator assembly (81) is in fluid connection with the second hydraulic motor (34) and delivers hydraulic fluid to or receives hydraulic fluid from the second hydraulic motor (34) depending on the rotation direction of the first hydraulic motor (33).

15. Method according to claim 14, wherein the hydraulic drive system is in the hoisting mode when the load (25) is above the water line and wherein the hydraulic drive is switched between the hoisting mode and the heave compensation mode when the load (25) is submerged in the water.

Ansprüche

1. Schiff (1) umfassend einen Rumpf (5) und ein Wellenausgleichssystem (30) für eine Last (25), die am Rumpf (5) aufgehängt ist, wobei das Wellenausgleichssystem eine Winde (31) mit einer Trommel (36) an dem Rumpf (5) und einem Hubseil (21) um die Trommel zum Heben und Aufhängen der Last umfasst, gekennzeichnet durch einen ersten hydraulischen Motor (33) und einem zweiten hydraulischen Motor (34), die mit der Trommel (36) wirkverbunden sind, um synchron mit der Trommel zu drehen, wobei die hydraulischen Motoren (33, 34) jeweils einen ersten Anschluss für Hydraulikflüssigkeit und einen zweiten Anschluss für Hydraulikflüssigkeit besitzen, um die hydraulischen Motoren (33, 34) und die Winde (31) in Abhängigkeit davon, in welchen Anschluss die Hydraulikflüssigkeit zugeführt wird, in die beiden entgegengesetzten Drehrichtungen anzutreiben, und ein hydraulisches Antriebssystem mit einem Hydraulikkreislauf, um die Hydraulikflüssigkeit durch die ersten Anschlüsse und die zweiten Anschlüsse der hydraulischen Motoren (33, 34) zu lenken, wobei das hydraulische Antriebssystem eine angetriebene Quelle für Hydraulikflüssigkeit (41, 42) umfasst, um unter Druck stehende Hydraulikflüssigkeit bereitzustellen, eine erste Hydraulikspeicheranordnung (81), um Hydraulikflüssigkeit zu speichern und vorzuspannen, eine erste Ventilanordnung (51) in einer Hydraulikflüssigkeitsverbindung zwischen der Quelle für Hydraulikflüssigkeit (41) und den Anschlüssen der hydraulischen Motoren (33, 34), eine zweite Ventilanordnung (72) in einer Hydraulikflüssigkeitsverbindung zwischen der ersten Ventilanordnung (51) und dem ersten Anschluss des zweiten hydraulischen Motors (34), und eine dritte Ventilanordnung (73) in einer Hydraulikflüssigkeitsverbindung zwischen der ersten Hydraulikspeicheranordnung (81) und dem ersten Anschluss des zweiten hydraulischen Motors (34), wobei das hydraulische Antriebssystem in der Lage ist, mittels der zweiten Ventilanordnung (72) und der dritten Ventilanordnung (73) zwischen einem Hubmodus und einem Wellenausgleichsmodus umzuschalten, wobei im Hubmodus die Hydraulikflüssigkeit parallel von der ersten Ventilanordnung (51) in beide ersten Anschlüsse der hydraulischen Motoren (33, 34) oder parallel in beide zweiten Anschlüsse der hydraulischen Motoren (33, 34) zugeführt wird, um die Drehung der Winde (31) in eine der entgegengesetzten Drehrichtungen anzutreiben, und wobei im Wellenausgleichsmodus die hydraulische Flüssigkeit von der ersten Ventilanordnung (51) in den ersten Anschluss des ersten hydraulischen Motors (33) oder in den zweiten Anschluss des ersten hydraulischen Motors (33) zugeführt wird, um die Drehung der Winde (31) in eine der Drehrichtungen anzutreiben, und die erste Hydraulikspeicheranordnung (81) die Hydraulikflüssigkeit zu dem ersten Anschluss des zweiten hydraulischen Motors (34) vorspannt.

2. Schiff (1) gemäß Anspruch 1, wobei der erste hydraulische Motor (33) ein hydraulischer Verstellmotor ist, der zwischen einem Modus hoher Flüssigkeitsverdrängung, in welchem ein erstes hohes Drehmoment unter Verwendung einer ersten Menge von Hydraulikflüssigkeit pro Umdrehung bereitgestellt wird, und einem Modus niedriger Flüssigkeitsverdrängung, in welchem ein niedrigeres zweites Drehmoment unter Verwendung einer geringeren zweiten Menge von Hydraulikflüssigkeit pro Umdrehung bereitgestellt wird, wechseln kann, wobei sich im Hubmodus der erste hydraulische Motor (33) im Modus hoher Verdrängung befindet und wobei sich im Wellenausgleichsmodus der erste hydraulische Motor (33) im Modus niedriger Verdrängung befindet, wobei der erste hydraulische Motor (33) vorzugsweise ein hydraulischer Motor mit Zweipunktverstellung ist, der zwischen dem Modus hoher Verdrängung und dem Modus niedriger Verdrängung umschalten kann.

3. Schiff (1) gemäß Anspruch 2, wobei der erste hydraulische Motor (33) ein hydraulischer Radialkolbenmotor ist, bei welchem die Anzahl der aktiven Radialkolben einstellbar ist.

4. Schiff (1) gemäß einem der vorhergehenden Ansprüche, wobei der zweite hydraulische Motor (34) ein hydraulischer Radialkolbenmotor ist.

5. Schiff (1) gemäß den Ansprüchen 2 und 4, wobei der zweite hydraulische Motor (34) das gleiche erste Drehmoment unter Verwendung der gleichen ersten Menge von Hydraulikflüssigkeit pro Umdrehung wie der erste hydraulische Motor (33) in seinem Modus hoher Flüssigkeitsverdrängung bereitstellt.

6. Schiff (1) gemäß einem der vorhergehenden Ansprüche, wobei das hydraulische Antriebssystem eine vierte Ventilanordnung (52) zwischen der Hydraulikflüssigkeitsversorgung (42) und der ersten Hydraulikspeicheranordnung (81) umfasst, um die erste Hydraulikspeicheranordnung (81) zu befüllen, nachzufüllen oder vorzuspannen.

7. Schiff (1) gemäß einem der vorhergehenden Ansprüche, wobei das hydraulische Antriebssystem eine zweite Hydraulikspeicheranordnung (82), um Hydraulikflüssigkeit zu speichern und vorzuspannen, eine fünfte Ventilanordnung (74) in einer Hydraulikflüssigkeitsverbindung zwischen der ersten Ventilanordnung (51) und dem zweiten Anschluss des zweiten hydraulischen Motors (34), und eine sechste Ventilanordnung (75) zwischen der zweiten Hydraulikspeicheranordnung (82) und dem zweiten Anschluss des zweiten hydraulischen Motors (34) umfasst, wobei die zweite Hydraulikspeicheranordnung (82) die Hydraulikflüssigkeit zu dem zweiten Anschluss des zweiten hydraulischen Motors (34) vorspannt, wobei das hydraulische Antriebssystem vorzugsweise eine siebte Ventilanordnung (53) zwischen der Quelle für Hydraulikflüssigkeit (42) und der zweiten Hydraulikspeicheranordnung (82) umfasst, um die zweite Hydraulikspeicheranordnung (82) zu befüllen, nachzufüllen oder vorzuspannen.

8. Schiff (1) gemäß Anspruch 7, wobei der Druck der Hydraulikflüssigkeit in der vorgespannten ersten Hydraulikspeicheranordnung (81) höher als der Druck der Hydraulikflüssigkeit in der vorgespannten zweiten Hydraulikspeicheranordnung (82) ist.

9. Schiff (1) gemäß einem der vorhergehenden Ansprüche, wobei die erste Hydraulikspeicheranordnung (81) und die zweite Hydraulikspeicheranordnung (82), sofern vorhanden, ein Freikolbenspeicher umfassend einen Zylinder (83) mit einem Anschluss zum Durchlass der Hydraulikflüssigkeit und einem Kolben (84), der im Zylinder (83) verschiebbar ist, um die Hydraulikflüssigkeit zum Anschluss vorzuspannen, ist, wobei der Freikolbenspeicher vorzugsweise ein vorgespanntes oder unter Druck stehendes Volumen an Gas (86) aufweist, das von der Hydraulikflüssigkeit durch den Kolben (84) getrennt ist, wobei das hydraulische Antriebssystem vorzugsweise einen Verstellsensor zur Bestimmung der Position des Kolbens (84) in seiner Gleitrichtung umfasst.

10. Schiff (1) gemäß einem der vorhergehenden Ansprüche, wobei die erste Ventilanordnung (51) ein bidirektionales Proportionalventil umfasst.

11. Schiff (1) gemäß einem der vorhergehenden Ansprüche, wobei das Wellenausgleichsystem (30) eine Bremse (37) für die Trommel umfasst, die während des Umschaltens zwischen dem Hubmodus und dem Wellenausgleichmodus aktiviert wird.

12. Schiff (1) gemäß einem der vorhergehenden Ansprüche, wobei das hydraulische Antriebssystem einen Regler umfasst, der mit der ersten Ventilanordnung (51) wirkverbunden ist, um die erste Ventilanordnung in Reaktion auf Hub-, Schlinger- und Neigungsparameter des Rumpfes (5) unter Berücksichtigung einer Bezugshöhe für die Last (25) zu steuern.

13. Schiff (1) gemäß einem der vorhergehenden Ansprüche, das als ein Wasserinjektionsbaggerschiff konfiguriert ist, wobei die Last (25) eine Düsenleiste ist (25), die mit einer Reihe von Wasserstrahldüsen (26) ausgestattet ist, wobei die Düsenleiste (25) unter Wasser am Rumpf (5) aufgehängt ist.

14. Verfahren für das Aufhängen einer Last (25) an einem Schiff (1), wobei das Schiff (1) einen Rumpf (5) und ein Wellenausgleichsystem (30) für die Last (25), die am Rumpf (5) des Schiffs (1) aufgehängt ist, umfasst, wobei das Wellenausgleichsystem (30) eine Winde (31) mit einer Trommel (36) an dem Rumpf (5) und ein Hubseil (21) um die Trommel (36) zum Heben und Aufhängen der Last (5) umfasst, gekennzeichnet durch einen ersten hydraulischen Motor (33) und einen zweiten hydraulischen Motor (34), die mit der Trommel (36) wirkverbunden sind, um synchron mit der Trommel (36) zu drehen, und ein hydraulisches Antriebssystem mit einem hydraulischem Kreislauf, um die Hydraulikflüssigkeit durch die hydraulischen Motoren (33, 34) zu leiten, wobei das hydraulische Antriebssystem eine angetriebene Quelle für Hydraulikflüssigkeit (41, 42) umfasst, um unter Druck stehende Hydraulikflüssigkeit bereitzustellen, und eine erste Hydraulikspeicheranordnung (81), um Hydraulikflüssigkeit zu speichern und vorzuspannen, wobei das Verfahren das Umschalten des hydraulischen Antriebs zwischen einem Hubmodus und einem Wellenausgleichsmodus während des Hebens der Last (25) umfasst, wobei in dem Hubmodus die Hydraulikflüssigkeit von der Quelle für Hydraulikflüssigkeit (41) parallel sowohl durch den ersten hydraulischen Motor (33) als auch den zweiten hydraulischen Motor (34) geführt wird, um die Drehung der Winde (31) in eine der entgegengesetzten Drehrichtungen anzutreiben, und wobei im Wellenausgleichmodus die Hydraulikflüssigkeit von der Quelle für Hydraulikflüssigkeit (41) durch den ersten hydraulischen Motor (33) geführt wird, während die erste Hydraulikspeicheranordnung (81) in flüssiger Verbindung mit dem zweiten hydraulischen Motor (34) steht und in Abhängigkeit von der Drehrichtung des ersten hydraulischen Motors (33) Hydraulikflüssigkeit an den zweiten hydraulischen Motor (34) abgibt oder von diesem aufnimmt.

15. Verfahren gemäß Anspruch 14, wobei das hydraulische Antriebssystem in dem Hubmodus ist, wenn sich die Last (25) oberhalb der Wasserlinie befindet und wobei der hydraulische Antrieb zwischen dem Hubmodus und dem Wellenausgleichsmodus umgeschaltet wird, wenn die Last (25) in das Wasser eingetaucht wird.

Revendications

1. Navire (1) comprenant une coque (5) et un système de compensation de pilonnement (30) pour une charge (25) qui est suspendue à la coque (5), dans lequel le système de compensation de pilonnement comprend un treuil (31) pourvu d'un tambour (36) sur la coque (5) et un câble de levage (21) autour du tambour pour le levage et la suspension de la charge, caractérisé par :
un premier moteur hydraulique (33) et un deuxième moteur hydraulique (34) qui sont en liaison fonctionnelle avec le tambour (36) pour tourner de manière synchrone avec le tambour, où les moteurs hydrauliques (33, 34) présentent chacun un premier orifice de fluide hydraulique et un deuxième orifice de fluide hydraulique pour entraîner les moteurs hydrauliques (33, 34) et le treuil (31) dans les deux sens de rotation opposés en fonction de l'orifice à l'intérieur duquel le fluide hydraulique est amené, et un système d'entraînement hydraulique pourvu d'un circuit hydraulique pour commander le fluide hydraulique à travers les premiers orifices et les deuxièmes orifices des moteurs hydrauliques (33, 34), où le système d'entraînement hydraulique comprend une source de fluide hydraulique (41, 42) motorisée pour fournir un fluide hydraulique sous pression, un premier ensemble accumulateur hydraulique (81) pour stocker et solliciter le fluide hydraulique, un premier ensemble soupape (51) en liaison fluidique hydraulique entre la source de fluide hydraulique (41) et les orifices des moteurs hydrauliques (33, 34), un deuxième ensemble soupape (72) en liaison fluidique hydraulique entre le premier ensemble soupape (51) et le premier orifice du deuxième moteur hydraulique (34), et un troisième ensemble soupape (73) en liaison fluidique hydraulique entre le premier ensemble accumulateur (81) et le premier orifice du deuxième moteur hydraulique (34), où le système d'entraînement hydraulique est apte à basculer entre un mode levage et un mode compensation de pilonnement au moyen du deuxième ensemble soupape (72) et du troisième ensemble soupape (73), où, dans le mode levage, le fluide hydraulique provenant du premier ensemble soupape (51) est amené en parallèle à l'intérieur des deux premiers orifices des moteurs hydrauliques (33, 34) ou en parallèle à l'intérieur des deux deuxièmes orifices des moteurs hydrauliques (33, 34) pour entraîner la rotation du treuil (31) dans un des sens de rotation opposés, et où, dans le mode compensation de pilonnement, le fluide hydraulique provenant du premier ensemble soupape (51) est amené à l'intérieur du premier orifice du premier moteur hydraulique (33) ou à l'intérieur du deuxième orifice du premier moteur hydraulique (33) pour entraîner la rotation du treuil (31) dans un des sens de rotation, et le premier ensemble accumulateur hydraulique (81) sollicite le fluide hydraulique vers le premier orifice du deuxième moteur hydraulique (34).

2. Navire (1) selon la revendication 1, dans lequel le premier moteur hydraulique (33) est un moteur hydraulique à cylindrée variable qui peut effectuer un passage entre un mode de déplacement de fluide élevé, dans lequel un premier couple est délivré au moyen d'une première quantité de fluide hydraulique par rotation, et un mode déplacement de fluide faible dans lequel un deuxième couple inférieur est délivré au moyen d'une deuxième quantité plus faible de fluide hydraulique par rotation, dans lequel, dans le mode levage, le premier moteur hydraulique (33) se trouve dans le mode déplacement élevé et dans lequel, dans le mode compensation de pilonnement, le premier moteur hydraulique (33) se trouve dans le mode déplacement de fluide faible, dans lequel le premier moteur hydraulique (33) est de préférence un moteur hydraulique à double cylindrée qui peut basculer entre le mode déplacement élevé et le mode déplacement faible.

3. Navire (1) selon la revendication 2, dans lequel le premier moteur hydraulique (33) est un moteur hydraulique à pistons radiaux dans lequel le nombre de pistons radiaux actifs est réglable.

4. Navire (1) selon l'une quelconque des revendications précédentes, dans lequel le deuxième moteur hydraulique (34) est un moteur hydraulique à pistons radiaux.

5. Navire (1) selon les revendications 2 et 4, dans lequel le deuxième moteur hydraulique (34) délivre le même premier couple au moyen de la même première quantité de fluide hydraulique par rotation que le premier moteur hydraulique (33) dans son mode déplacement de fluide élevé.

6. Navire (1) selon l'une quelconque des revendications précédentes, dans lequel le système d'entraînement hydraulique comprend un quatrième ensemble soupape (52) entre la source de fluide hydraulique (42) et le premier ensemble accumulateur hydraulique (81) pour remplir, remplir à nouveau ou solliciter le premier ensemble accumulateur hydraulique (81).

7. Navire (1) selon l'une quelconque des revendications précédentes, dans lequel le système d'entraînement hydraulique comprend un deuxième ensemble accumulateur hydraulique (82) pour stocker et solliciter le fluide hydraulique, un cinquième ensemble soupape (74) en liaison fluidique hydraulique entre le premier ensemble soupape (51) et le deuxième orifice du deuxième moteur hydraulique (34), et un sixième ensemble soupape (75) entre le deuxième ensemble accumulateur hydraulique (82) et le deuxième orifice du deuxième moteur hydraulique (34), dans lequel le deuxième ensemble accumulateur hydraulique (82) sollicite le fluide hydraulique vers le deuxième orifice du deuxième moteur hydraulique (34), dans lequel le système d'entraînement hydraulique comprend de préférence un septième ensemble soupape (53) entre la source de fluide hydraulique (42) et le deuxième ensemble accumulateur hydraulique (82) pour remplir, remplir à nouveau ou solliciter le deuxième ensemble accumulateur hydraulique (82).

8. Navire (1) selon la revendication 7, dans lequel la pression du fluide hydraulique dans le premier ensemble accumulateur hydraulique (81) sollicité est supérieure à la pression du fluide hydraulique dans le deuxième ensemble accumulateur hydraulique (82) sollicité.

9. Navire (1) selon l'une quelconque des revendications précédentes, dans lequel le premier ensemble accumulateur hydraulique (81), et le deuxième ensemble accumulateur (82), lorsqu'il est présent, est un accumulateur à pistons libres comprenant un cylindre (83) pourvu d'un orifice pour le passage du fluide hydraulique et un piston (84) qui peut coulisser à travers le cylindre (83) pour solliciter le fluide hydraulique vers l'orifice, dans lequel l'accumulateur à pistons libres comprend de préférence un volume sollicité ou sous pression de gaz (86) qui est séparé du fluide hydraulique par le piston (84), dans lequel le système d'entraînement hydraulique comprend de préférence un capteur de déplacement pour déterminer la position du piston (84) dans sa direction de coulissement.

10. Navire (1) selon l'une quelconque des revendications précédentes, dans lequel le premier ensemble soupape (51) comprend une soupape bidirectionnelle proportionnelle.

11. Navire (1) selon l'une quelconque des revendications précédentes, dans lequel le système de compensation de pilonnement (30) comprend un frein (37) pour le tambour destiné à être activé pendant le basculement entre le mode levage et le mode compensation de pilonnement.

12. Navire (1) selon l'une quelconque des revendications précédentes, dans lequel le système d'entraînement hydraulique comprend un dispositif de commande qui est en liaison fonctionnelle avec le premier ensemble soupape (51) pour commander le premier ensemble soupape en réponse à des paramètres de pilonnement, de roulis et de tangage de la coque (5) par rapport à une hauteur de référence pour la charge (25).

13. Navire (1) selon l'une quelconque des revendications précédentes, configuré comme un navire de dragage à injection d'eau, dans lequel la charge (25) est une barre à jet (25) qui est pourvue d'une série de buses à jet d'eau (26), dans lequel la barre à jet (25) est suspendue sous l'eau à partir de la coque (5).

14. Procédé de suspension d'une charge (25) à partir d'un navire (1), dans lequel le navire (1) comprend une coque (5) et un système de compensation de pilonnement (30) pour la charge (25) qui est suspendue à la coque (5) du navire (1), dans lequel le système de compensation de pilonnement (30) comprend un treuil (31) pourvu d'un tambour (36) sur la coque (5) et un câble de levage (21) autour du tambour (36) pour le levage et la suspension de la charge (25), caractérisé par :
un premier moteur hydraulique (33) et un deuxième moteur hydraulique (34) qui sont en liaison fonctionnelle avec le tambour (36) pour tourner de manière synchrone avec le tambour (36), et un système d'entraînement hydraulique pourvu d'un circuit hydraulique pour commander le fluide hydraulique à travers les moteurs hydrauliques (33, 34), où le système d'entraînement hydraulique comprend une source de fluide hydraulique (41, 42) motorisée pour fournir un fluide hydraulique sous pression et un premier ensemble accumulateur hydraulique (81) pour stocker et solliciter le fluide hydraulique, où le procédé comprend le basculement de l'entraînement hydraulique entre un mode levage et un mode compensation de pilonnement pendant le levage de la charge (25), dans lequel, dans le mode levage, le fluide hydraulique provenant de la source de fluide hydraulique (41) est amené en parallèle à travers à la fois le premier moteur hydraulique (33) et le deuxième moteur hydraulique (34) pour entraîner la rotation du treuil (31) dans un des sens de rotation opposés, et dans lequel, en mode compensation de pilonnement, le fluide hydraulique provenant de la source de fluide hydraulique (41) est amené à travers le premier moteur hydraulique (33) pendant que le premier ensemble accumulateur hydraulique (81) est en liaison fluidique avec le deuxième moteur hydraulique (34) et distribue le fluide hydraulique au deuxième moteur hydraulique (34) ou en reçoit de celui-ci en fonction du sens de rotation du premier moteur hydraulique (33).

15. Procédé selon la revendication 14, dans lequel le système d'entraînement hydraulique se trouve en mode levage lorsque la charge (25) se situe au-dessus de la ligne de flottaison et dans lequel l'entraînement hydraulique est amené à basculer entre le mode levage et le mode compensation de pilonnement lorsque la charge (25) est immergée dans l'eau.

Drawing