Abstract: A device for opening and closing bottom outlets of a plurality of cargo pockets arranged in rows, preferably in holds in bulk cargo ships, conveyors being arranged beneath the pockets. A guide arrangement extends longitudinally along the bottom of a row of pockets and carries covers for the bottom outlets of the pockets. Said covers are journalled for horizontal movement in the longitudinal direction of the guide arrangement between opened and closed positions. At least one carriage can be moved parallel to said guide arrangement and can be driven forward to an arbitrary cover. Said carriage is provided with a drive movable from an inoperative position to a position in which they are engaged with the chosen cover in order to, during subsequent movement of the carriage in either direction, move the cover to an open or closed position. Then the drive can be moved to the inoperable position in order to allow the movement of the carriage to another cover.