Abstract: A propeller assembly (2), a so-called thruster, intended to be fitted to an opening (7) in a bottom part (1) of the shell structure of a watercraft, for example an offshore-platform, is provided with a mounting flange (9) which can be connected in a pressure tight fashion to the shell structure around the opening (7). To enable the assembly to be fitted and dismantled from outside the shell structure and beneath the surface of the water on which the craft floats without requiring the assistance of a diver there are used a plurality of lines (12) which can be connected to lifting devices in the watercraft and passed out through a corresponding number of line openings (13) located in the shell structure on one side of the assembly mounting opening (7), so that the ends of the lines can be connected to the line attachments (16; 37) on the assembly (2).

Abstract: The invention relates to a reversing means in a marine-water-jet propulsion unit, which includes a pump (4) having connected thereto a nozzle tube (14) for directing the driving jet of water. The lower wall (14a) of the tube is provided with an opening (16), and the reversing means includes an inner flap (17) and an outer flap (18) arranged to close the opening from the inside and the outside respectively of the tube. The inner flap (17) can be swung about its fore end, as seen in the direction of flow of water through the tube, between the closed position and a position in which it is swung inwardly in the tube (14), in which position the flap (17) completely or partially blocks the flow path through the tube and deflects the water flow completely or partially out through the opening (16) in the wall of the tube.

Abstract: A water jet unit for ships, comprises a propeller pump having a pump housing connected on its inlet side with an inlet channel and on its outlet side with a water-jet directing outlet means. The pump housing has a hub housing which is arranged centrally in the flow path of the water through the pump housing and which is carried by guide vanes extending radially between the wall of the pump housing and the hub housing. The impeller is mounted on the end of a pump shaft extending into the pump housing through the inlet channel and is journalled in the hub housing by means of an axial bearing and a radial bearing. Both bearings are spherical and have a substantially common center.

Abstract: Apparatus for mounting and dismounting a submerged propeller unit to and from the hull of a floating body from the outside thereof comprises a flange in the hull surrounding an opening therein and having passages therein, a flange on the propeller unit having fasteners at locations corresponding to the locations of the passages in the hull flange, a drive coupling member on the propeller unit, a plurality of guides on the propeller unit for guiding the coupling member into the hull opening and for positioning the propeller unit flange in proper relation to the hull flange as the propeller unit is raised into position, a lifting yoke carrying a plurality of lifting cables extending through watertight ways in the hull and adapted to be secured detachably to the propeller unit whereby the propeller unit flange may be raised to the level of the hull flange with the fasteners in the former in registry with the passages in the latter to facilitate securing the propeller unit flange to the hull flange.

Abstract: Apparatus for mounting and dismounting a submerged propeller unit to and from the hull of a floating body from the outside thereof comprising a flange in the hull surrounding an opening therein and having passages therein, a flange on the propeller unit having fasteners at locations corresponding to the locations of the passages in the hull flange, a drive coupling member on the propeller unit, a plurality of guides on the propeller unit for guiding the coupling member into the hull opening and for positioning the propeller unit flange in proper relation to the hull flange as the propeller unit is raised into position, a plurality of cables secured at their upper ends to a hoisting cable with their lower ends extending through watertight ways in the hull for coupling detachably to a plurality of locations on the propeller unit, spreaders located between the hoisting cable and the floating body for positioning the cables in substantial alignment with the respective cable ways in the hull, the cable ways being