Abstract: A drag head of a trailing suction hopper dredger, comprises a visor which is dragged over the bottom in a dragging direction and herein loosens soil, and a suction conduit which connects to the visor and which discharges the loosened soil. The drag head is provided with cutting bodies for loosening the soil, with the proviso that the cutting bodies comprise conical bits. Harder soil can be dredged efficiently with a trailing suction hopper dredger equipped with the drag head.

Abstract: A cutter head for dredging ground under water is disclosed. The cutter head is suitable for attachment to the ladder of a cutter suction dredger and for being moved through the ground therewith in a lateral sweeping movement. The cutter head includes a rotation-symmetrical revolving body which is rotatable around its rotation axis by means of drive means and which is provided along its peripheral surface with a number of cutting tools for penetrating into the ground, wherein the rotation axis of the cutter head runs substantially perpendicularly of the longitudinal direction of the ladder and substantially tangentially to the direction of the sweeping movement. Likewise, a method for breaking ground underwater, making use of the cutter head is shown.

Abstract: A cutter head according to the invention is particularly suitable for breaking relatively hard ground, is self-sharpening and has an extended service life.

Abstract: A drag head of a trailing suction hopper dredger. The drag head comprises a rotatable visor connected to a suction pipe for discharging soil via the suction opening of the visor, wherein the visor is provided with a catching construction for undesirable objects. The catching construction closes the suction opening except for passage openings, wherein at least a number of passage openings have a variable passage area. A method for breaking up and/or dredging at least partially hard grounds under water using a trailing suction hopper dredger equipped with a drag head.

Abstract: The invention relates to a drag head (1) of a trailing suction hopper dredger, comprising a visor (2) which is dragged over the bottom in a dragging direction and herein loosens soil, and a suction conduit (5) which connects to the visor (2) and which discharges the loosened soil. The drag head is provided with cutting bodies for loosening the soil, with the proviso that the cutting bodies comprise bits (20). Harder soil can also be dredged with the drag head by applying bits (20). The invention also relates to a method for dredging at least partially hard bottoms under water with a trailing suction hopper dredger equipped with the drag head.

Abstract: A cutter head for dredging ground under water is disclosed. The cutter head is suitable for attachment to the ladder of a cutter suction dredger and for being moved through the ground therewith in a lateral sweeping movement. The cutter head includes a rotation-symmetrical revolving body which is rotatable around its rotation axis by means of drive means and which is provided along its peripheral surface with a number of cutting tools for penetrating into the ground, wherein the rotation axis of the cutter head runs substantially perpendicularly of the longitudinal direction of the ladder and substantially tangentially to the direction of the sweeping movement. Likewise, a method for breaking ground underwater, making use of the cutter head is shown.

Abstract: The invention relates to a drag head of a trailing suction hopper dredger. The drag head comprises a visor which is dragged over the bottom and herein loosens soil, and a suction pipe which is connected to the visor and which discharges the loosened soil. The visor comprises at least two individually movable pressure elements transversely of the dragging direction which comprise a number of substantially disc-shaped penetrating bodies. The penetrating bodies transmit forces to the bottom via their peripheral edge under the influence of the weight of the pressure element in which they are received, whereby the bottom is broken. The drag head has an improved efficiency.

Abstract: The present invention relates to a draghead (1) for a trailing suction hopper, comprising a visor (2), revolvable around a first axis (6) for removing soil, and a suction line (31) connected to the visor (2) for the removal of the loosened soil, characterised in that the draghead (1) is provided with a pressure plate (21), which comprises a number of mainly disc-shaped penetrating bodies (22) on the soil-facing side of the pressure plate (21), in such a way that their circumferential edge (23) is capable of transferring forces to the soil.

Abstract: A drag head of a trailing suction hopper dredger. The drag head comprises a rotatable visor connected to a suction pipe for discharging soil via the suction opening of the visor, wherein the visor is provided with a catching construction for undesirable objects. The catching construction closes the suction opening except for passage openings, wherein at least a number of passage openings have a variable passage area. A method for breaking up and/or dredging at least partially hard grounds under water using a trailing suction hopper dredger equipped with a drag head.

Abstract: A cutter head for dredging soil, which is mountable to the ladder of a suction dredger for dredging soil, and connectable on a suction pipe for removing loosened soil, the cutter head comprising a cage-shaped support construction which is mountable to a drivable rotation shaft extending mainly in extension of the ladder and which has a circumferential surface provided with a number of cuffing tools for penetrating the soil, the cuffing tools comprising a number of disc-shaped penetration bodies of which the disc planes extend substantially perpendicular to the rotation shaft, so that they can transfer forces to the soil via their peripheral edges.

Abstract: A cutter head for dredging soil, which is mountable to the ladder of a suction dredger for dredging soil, and connectable on a suction pipe for removing loosened soil, the cutter head comprising a cage-shaped support construction which is mountable to a drivable rotation shaft extending mainly in extension of the ladder and which has a circumferential surface provided with a number of cutting tools for penetrating the soil, the cutting tools comprising a number of disc-shaped penetration bodies of which the disc planes extend substantially perpendicular to the rotation shaft, so that they can transfer forces to the soil via their peripheral edges.

Abstract: The present invention relates to a draghead (1) for a trailing suction hopper, comprising a visor (2), revolvable around a first axis (6) for removing soil, and a suction line (31) connected to the visor (2) for the removal of the loosened soil, characterised in that the draghead (1) is provided with a pressure plate (21), which comprises a number of mainly disc-shaped penetrating bodies (22) on the soil-facing side of the pressure plate (21), in such a way that their circumferential edge (23) is capable of transferring forces to the soil.