Abstract: A method for assembling a simulator in which a visual display system is arranged to display an image for viewing from a predetermined viewing position within a simulated viewing station. The visual display system and viewing station are mounted on a base. The viewing station is fabricated such that the location of the viewing position relative to the viewing station is established. The visual display system is fabricated so that when mounted in a predetermined position on the base the location of the viewing position relative to the base is established. When the viewing station and visual display system are mounted on the base, the visual display system is mounted in the predetermined position, and the viewing station being mounted at a position relative to the base selected such that the eye position of a person sat within the viewing station coincides with the location of the viewing position relative to the base.

Abstract: An alarm circuit is interlocked with the start circuit of power driven industrial machinery such as a coal tipple so that before the machinery can be started, an alarm must be energized for a predetermined time to alert personnel that the machine is about to start. In the event that the machinery is not started within a predetermined time after termination of the alarm, or in the event that the alarm has not actually sounded, the whole cycle must be repeated.

Abstract: An alarm circuit is interlocked with the start circuit of power driven industrial machinery such as a coal tipple so that before the machinery can be started, an alarm must be energized for a predetermined time to alert personnel that the machine is about to start. In the event that the machinery is not started within a predetermined time after termination of the alarm, the whole cycle must be repeated.