Abstract: A device for elevating water by means of a vertical chain (5,21) of buckets (10,20) supported and driven by an upper reversing wheel (7,25), the lower part of the bucket chain (5,21) running through a filling tank (1,15) having a height adjustable overflow edge (4,18) over which water from the lower level (2,19) may flow into the passing buckets (10,20). Structure (11,25') is provided for discharging the buckets (10,20) at the higher level (13,39). The bucket chain (21) in its entirety preferably is adjustable in the vertical direction.

Abstract: Method for controlling the position of the suction head of a dredge in relation to the sludge layer on the bottom of a water way. Acoustic pulses are transmitted in front of the suction head from the dredge to the bottom. The reflected pulses are received and the time difference between the transmitting and the receiving moment is determined as well as the energy difference between the transmitted and received pulses. Based on these differences the configuration and composition of the sludge layers as well as the preferred position of the suction head in relation to said sludge is determined. Thereafter the system for controlling the position of said suction head is operated to bring the suction head into the most favorable position.

Abstract: Large vessel having an opening in the bottom of the hull said hull portion being provided with an upwardly and downwardly movable grid structure shielding the opening against ice flakes which pass along the bottom of the hull.

Abstract: The invention relates to a suction dredge barge in which the air chambers (8,9) on either side of the hold (2) can be filled with mud via an overflow (14) at the top edge of the hold (2) said air chambers (8,9) having inclined bottoms (10,11) and discharge openings (12,13) towards the hold at the lower edge of said inclined bottoms (10,11).