Abstract: A hopper barge has an unloading opening covered by a slide that moves parallel to the plane of the opening. In the closed position, the slide is sealed by an inflatable seal disposed in a channel that opens toward the slide and that surrounds the opening.

Abstract: A suction dredging system comprises a vessel having an arm pivotally secured to it which can be positioned and held in an obliquely downwardly directed position and which itself comprises upper and lower parts which are pivotally interconnected with a link between them, the link making an angle with both parts of the arm so that motions of the upper part of the arm in the vertical plane are not or are hardly transmitted to the lower part of the arm by both parts of the arm. The lower part supports a suction mouth of a suction pipe as well as a rotary cutter whose shaft is disposed in the vertical plane of the arm, the lower part of the arm being stabilized by means of a hydropneumatic spring. A second hydropneumatic spring acts horizontally on the assembled link and lower part of the arm and cutter.