Abstract: A hopper barge having at least two longitudinal air chambers interconnected pivotally at deck level, which chambers in a loading position bound an upwardly open well and in an unloading position release a discharge opening at the bottom, and comprising at least one control unit for controlling the relative position of the air chambers, with per each control unit two synchronously controlled jack means, which are each pivotally connected with at least one of the air chambers by on the one end a lever arm, which two lever arms are arranged in substantially mirror-symmetrical relationship relative to the median longitudinal plane of the vessel and being interconnected pivotally, and on the other end a hinge fixedly secured to one of the air chambers.

Abstract: A hydraulic synchronous driving mechanism provided with at least two piston-cylinder assemblies, each having a bottom chamber and a ring chamber and the piston rods of which engage a counterdevice adapted to synchronously load piston rods mutually in opposite directions, a hydraulic fluid circuit provided with at least a pump and a reservoir, whereby there are pair-wise arranged volumetric pump-motors in fluid lines throughconnected to the bottom chamber of the one cylinder and the ring chamber of the other cylinder, which pump-motors are mutually coupled for a constant supply ratio, while the fluid line sections extending from the pump-motors to the cylinders are throughconnected to only one cylinder chamber.