Abstract: In a system for locking freight or cargo, especially in the freight hold of an aircraft, including guide rails along which the units of freight are guided, and YZ-locking devices for securing or locking the freight units against motion in the Y- and Z-directions, one or more X-locking devices are further provided for locking the freight units against motion in the X-direction. The X-locking devices are mounted directly on the guide rails, which are arranged between respective YZ-locking devices. Each X-locking device includes a mounting base (5) that is fixedly mounted on the guide rail (1), and a locking member (6) that is pivotally connected to the mounting base (5) so as to be tiltable or pivotable about an axis (7) extending parallel to the lengthwise extension of the guide rail (1) or X-direction.