Feeder vessel

Patent metadata

Field	Value
Publication number	US-12325610-B2
Application number	US-202017788099-A
Country	US
Kind code	B2
Filing date	Dec 18, 2020
Priority date	Dec 23, 2019
Publication date	Jun 10, 2025
Grant date	Jun 10, 2025

Abstract

A feeder vessel for the onshore-to-offshore transport of elongate wind turbine objects with a motion compensating carrier assembly having a motion compensated platform for receiving and retaining the elongate object, and a motion compensation mechanism. The motion compensation mechanism includes extendable actuators which passively compensate motions of the platform out of a neutral position, and winches driving carrier cables such that traction by the respective carrier winch counteracts an extension of at least one of the carrier actuators. The winches are embodied as active motion compensation winches to compensate movements of the platform.

First claim

The invention claimed is:

1. A feeder vessel for onshore-to-offshore transport of at least one elongate object,
the feeder vessel having a motion compensating carrier assembly supported on the hull, said carrier assembly having:
one motion compensated platform, configured for receiving and retaining thereon an elongate object, the platform comprising a top surface and a motion compensation mechanism connecting the one motion compensated platform to the hull and configured to provide compensating movements of the platform with respect to the hull,
said motion compensation mechanism comprising:
multiple extendable carrier actuators, each configured to extend and shorten along a respective longitudinal axis thereof, each connected at a respective first longitudinal end thereof via a respective first pivotal coupling to the hull and at a respective second longitudinal end via a second pivotal coupling to the platform; and
one or more carrier winches, each carrier winch configured for driving a carrier cable of which a cable segment extends from the respective carrier winch to the platform, such that traction by the respective carrier winch counteracts an extension of at least one of the carrier actuators,

wherein the multiple extendable carrier actuators are embodied as passive motion compensators to provide passive compensating movements of the platform, and
wherein the one or more carrier winches are embodied as active motion compensation winches to provide active compensating movements of the platform.

2. The feeder vessel according to claim 1 , wherein the cable segment of the carrier cable driven by each carrier winch runs, in any upper position of the platform, parallel and directly next to the longitudinal axis of at least one of the carrier actuators assigned to the carrier winch.

3. The feeder vessel according to claim 1 , wherein the vessel comprises a lower support, secured to or integral with the hull, the carrier actuators being connected to the lower support at the first longitudinal end thereof for connection with the hull,
wherein the cable segment runs over one or more sheaves that are arranged in between the lower support and the platform, the one or more sheaves each being fixed to one of the lower support and the platform.

4. The feeder vessel according to claim 1 , wherein the one or more carrier winches are each embodied as an active heave compensating carrier winch.

5. The feeder vessel according to any one or more of claim 1 , wherein the one or more carrier winches are fixed below the platform, between the platform and the hull.

6. The feeder vessel according to claim 1 , wherein the motion compensated platform is movable into a range of upper positions thereof, said upper positions comprising a neutral position in which the platform is parallel to and spaced above an upper deck of the hull,
wherein the motion compensated platform is movable from the upper positions, including the neutral position, into a rest position in which the top surface of the platform is flush with the upper deck and the platform extends entirely within an opening in the upper deck.

7. The feeder vessel according to claim 1 , wherein the platform is laterally arranged next to one or more storage positions on an upper deck of the hull of the feeder vessel, which upper deck is configured for supporting and retaining one or more of said elongate objects in a longitudinal direction of the feeder vessel.

8. The feeder vessel according to claim 7 , wherein the platform is longitudinally arranged between fore and aft lateral skidding rails on the upper deck, laterally at least extending from the one or more storage positions to positions fore and aft of a lateral centre region of the platform, respectively, such that the elongate objects retained at the storage positions are skiddable via said fore and aft skidding rails to the lateral centre region of the platform to be supported onto said skidding rails above and longitudinally across the lateral centre region of the platform, at least while the platform is in a rest position thereof, in which the top surface of the platform is flush with the upper deck of the feeder vessel and the platform extends entirely within the opening in the upper deck.

9. A method for compensating motion of an elongate object on the feeder vessel according to claim 1 , the method comprising the steps of:
retaining the elongate object on the one platform in a transfer position thereof relative to the platform within a laterally central region of the motion compensated platform such that the elongate object extends in a longitudinal direction of the feeder vessel; and
compensating relative motions of the platform and the elongate object with respect to the feeder vessel to maintain a stationary position of the elongate object in space, by simultaneously:
passively compensating movements of the platform relative to the hull by means of an extension and shortening of the multiple extendable carrier actuators; and
actively compensating movements of the platform out of the neutral position by hauling in and paying out one or more carrier cables driven by one or more respective carrier winches, wherein said hauling in by each carrier winch shortens a cable segment of the respective carrier cable, thereby counteracting an extension of at least one of the carrier actuators.

10. A method for transferring an elongate object from the feeder vessel according to claim 1 to an offshore structure having a lifting device the method comprising the steps of:
retaining the elongate object on the platform in a transfer position thereof within a laterally central region of the motion compensated platform such that the elongate object extends in a longitudinal direction of the feeder vessel at least when the platform is in a neutral position on the feeder vessel;
compensating relative motions of the platform and the elongate object with respect to the feeder vessel to maintain a stationary position of the elongate object in space, at least by passively compensating movements of the platform relative to the hull, by means of an extension and shortening of multiple extendable carrier actuators upon movements of the platform out of the neutral position;
coupling the elongate object to an object suspension device of the lifting device; and subsequently
transferring the weight of the elongate object from the platform to the lifting device until at least 80% of the weight is supported thereby, and the remaining 20% or less of the weight is still supported by the platform; and subsequently
moving the platform downwards by hauling in one or more carrier cables driven by one or more respective carrier winches, such that said hauling in by each carrier winch shortens a cable segment of the driven carrier cable, said shortening counteracting an extension of at least one of the carrier actuators, the moving downwards taking place at a speed such that the platform moves away from the elongate object now entirely supported by the lifting device.

11. The method according to claim 10 , further comprising, substantially simultaneously with the step of moving the platform downwards, the step of:
initiating an upwards movement of the elongate object from the transfer position by the lifting device of the other offshore structure; and further comprising the subsequent step of:
moving the elongate object upwards from the transfer position by the lifting device of the other offshore structure, the moving upwards taking place at a speed such that the platform moves away from the elongate object now entirely supported by the lifting device of the other structure.

12. The method according to

Assignees

• Itrec Bv

Inventors

• Roodenburg Joop
• Tieleman Hubertus Lourens Leendert

Classifications

• B63B27/30

  {Arrangement of ship-based loading or unloading equipment} for transfer at sea between ships or between ships and off-shore structures · CPC title

• B63B27/10 Primary

  of cranes · CPC title

• Y02E10/727

  Offshore wind turbines · CPC title

• Y02E10/72

  Wind turbines with rotation axis in wind direction · CPC title

• B66F7/22

  with tiltable platforms (tilting vehicles for unloading B65G67/34) · CPC title