Abstract: The invention relates to an apparatus for removing oil from water, comprising a horizontal roller cooperating with a scraper blade as well as a receiving tray, the improvement being that the roller has its upper surface at the level of the water surface and is placed above the receiving tray and that between roller and the suction pump side of the receiving tray a grate has been placed, which cuts the collected oil into dischargeable pieces.

Abstract: A method for sucking up soil or sludge by means of a suction dredge provided with a suction pipe having a drag head. Through the suction pipe (1) water and soil or sludge are sucked up. The soil or the sludge is loosened in front of the inlet opening of the drag head. Said loosening operation takes place at such a distance from the inlet opening (4) of the drag head (3) that by the loosening operation the gases being liberated remain substantially out of the suction action of the drag head (3). The loosening is performed by injection nozzles (28) and/or cutting blades mounted in a frame (10) swingably mounted about a horizontal axis (9) on the suction tube (1).

Abstract: Drag head for a hopper suction dredge, which drag head has a suction opening in the dragging direction, defined by side walls and a rear wall. The lower edges of these walls are positioned in one plane whereby the rear edge is positioned lower then the upper edge of the inlet opening with respect to a vertical cross sectional plane parallel to the dredging direction. The side edges and the rear edge are positioned in an essentially horizontal plane. The rear wall of the drag head extends upwards along a compound bent line such that the tangent of this line at the height of a horizontal plane through the upper edge of the inlet opening is inclined forwards at an acute angle.

Abstract: A suction dredger provided with sweeping arms at the side of the vessel which arms can be placed at an angle with respect to the body of the vessel and are provided with suction apparatus to suck away the upper layer of the water collected in front of the sweeping arms to pump it into the hold of the vessel so that said hold optionally can be used for storing dredging material or oil respectively. The invention further relates to the construction of the apparatus for connecting the sweeping arms to the vessel and to move said arms from an inward storage position into an outboard operative position and vice versa, the sweeping arms being in a tilted position when inboard and if necessary displaceable in the longitudinal direction of the vessel along its deck so that in the case of a suction dredger the normal dredging apparatus can perform its function without being hampered by the sweeping arms, the construction of said apparatus being such that the sweeping arm can be applied to any other type of vessel.

Abstract: The invention relates to a dragging type head (1) of a suction dredger, the head having a driven cutting device in front of the suction tube mouth, which cutting device (5) rotates about a horizontal transverse axis and has cutting blades at its outer circumference. The main part of the cutting device (5) is enclosed by a cap (6) connected to the suction tube mouth (4). The cutting blades (e.g. 15,16,17,18,19 and 16', 17', 18', 19') are arranged in the form of several V-shaped patterns (11,12) upon the circumference with a channel digging type blade (15,20,27) at the leading top of each V. All the blades are shaped such that they move the cut material laterally towards the plane of the channel digging blades (15,20,27) and all the blades may be in the shape of a plough (28).

Abstract: A dragging type cutter head for a suction dredger has a cutting member that rotates about a horizontal axis and has at its periphery a series of cutting teeth disposed side-by-side in the axial direction. At the lowermost point in their rotation, the cutting teeth rotate in the dragging direction. The dragging head has an inlet opening for cut material, whose edges extend to the outer circle of rotation of the cutter teeth with the lower edge of that opening at the same level as the lower part of the cutting member. The cutting teeth are pivotal on horizontal axes spaced from that of the cutting member; and springs urge the cutting teeth about their axes in the cutting direction.

Abstract: A dragging type suction head for a suction dredger having a suction tube which extends downwardly and rearwardly from a vessel at the lower end of which the suction head is mounted. In this suction head, enclosed by a housing which at least at a rear side leaves free an entrance opening, a cutter is mounted rotating in a direction opposite the direction of dredging, said cutter being a cylindrical body with cutting blades at its circumference which blades feed immediately into an intake section connected to the suction tube. Between the inner edges of the cutting blades and a cylindrical drum, space is provided to allow for a passage through which water can flow. The blades are mounted between discs that have sharp cutting edges.