Dredge vessel system
AssigneeDamen Dredging Equipment B.V.
InventorsMarius Otto Winkelman, Hendrik Ratering
Life of this patent
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Abstract
A system for recovering immerged sediments from a seabed and discharging them. From a free sailing extraction ship a mixture of water and sediment is suctioned by a submerged pump unit through a flexible hose adapted to be rolled on a rotative reel positioned on the extraction ship, while the ship is sailing over the concession. The suctioned mixture is then immediately delivered to one of a series of free sailing carrier and transport units that sail alongside.
Claims11
A dredge vessel for recovering materials from a seabed and discharging said recovered materials into a barge, the dredge vessel comprising:
- a structure comprising a hull and a deck:
- a steering means and a motor for steering and moving the dredge vessel in a forward direction:
- a reel positioned on said deck:
- an elongated flexible suction hose and adapted to be rolled onto the reel and unrolled down into the water:
- a rigid dredging head connected to a first end of the flexible suction hose and having a first free end opened downward for downwardly directing a suction when resting on the seabed:
- a pump operably carried by the dredge vessel and operably coupled to the flexible suction hose for suctioning therethrough a mixture of said materials and water:
- a towing means comprising a towing cable extending downwardly and rearwardly from said dredge vessel structure to said rigid dredging head for transmitting towing forces to said dredging head and thereby isolating the flexible suction hose from towing forces;
- a hoisting means disposed on said deck and having at least two hanging ropes having hanging rope lengths extending from the ship to the dredging head, the hanging ropes each adapted to be wound and unwound and connected to both the rigid dredging head and a hanging rope length controller, for:
- moving the flexible suction hose and rigid dredging head between an inactive position located onboard the vessel and an active position located overboard, and
- immersing and elevating the flexible suction hose and rigid dredging head, the angular orientation of the dredging head relative to the seabed selectively changeable separate from and independent of the orientation of the suction hose and towing cable by manipulation of the hanging ropes,
- at least one delivery tube which is:
- operably coupled at a first end to the flexible suction hose, and
- operably coupled at a second end to a delivery head for discharging therethrough the recovered materials into said barge,
- said delivery tube and delivery head being adapted to move relative to said deck, such that the delivery tube and delivery head can be:
- stored above the deck in a stored orientation,
- and deployed outside the dredge vessel in an orientation when said recovered materials have to be discharged off the ship,
- wherein
- the towing cable adapted for:
- towing the immersed dredging head when the dredge vessel is moving forward and materials are being suctioned, and
- the at least two hanging ropes adapted for controlling a tilt of the rigid dredging head by adjustment of the lengths of the hanging ropes by the hanging rope length controller with its first free end directed backward and resting on the seabed,
- a suction hose length controller for controlling the length of the flexible suction hose unrolled from the reel,
- a main length controller connected to both the flexible suction hose length controller and the hanging rope length controller for adjusting the unrolled length of the flexible suction hose and an unwound length of the hanging ropes in such a way that the flexible suction hose is curved along the determined length when the dredge vessel is moving forward and said materials are being sucked, wherein the flexible suction hose has a determined length between the rigid dredging head and the sea surface.
A dredging method for recovering immersed materials from a seabed concession and discharging them, the method comprising:
- suctioning a mixture of water and materials through a flexible hose from a first free end of an immersed dredging head which is connected to a forward moving sailing dredge vessel through the flexible hose adapted to be rolled and unrolled on a rotative reel positioned on said dredge vessel
- delivering the materials from the dredge vessel to one of a series of barges, characterized in that:
- the step of suctioning comprises suctioning said mixture while:
- the dredge vessel is sailing frontward over the seabed concession,
- the immersed dredging head and flexible suction hose are towed by the dredge vessel, with a towing means comprising a towing cable extending downwardly and rearwardly from said dredge vessel and said dredging head for transmitting towing forces to said dredging head and thereby isolating the flexible suction hose from towing forces,
- an underwater tilt of the immersed dredging head is controlled by at least two hanging ropes having hanging rope lengths extending from the ship and connected to the dredging head, the angular orientation of the dredging head relative to the seabed selectively changeable separate from and independent of the orientation of the suction hose and towing cable by manipulation of the hanging ropes,
- such that said dredging head has its first free end directed backward and rested on the seabed, and,
- the flexible suction hose has an immersed length varied such that the flexible suction hose is curved therealong whatever the tilt of the dredging head, and
- the step of delivering comprises delivering said materials while said mixture is being suctioned.
Dependencies are inferred from the claim text.