These clusters of orange lights are placed, one at the end of the platform where the motorman of a stopped train can see them, and at the center, over the conductor's position (pictured). They are used by the dispatcher to hold an arriving train in the station, usually to make a connection with another arriving train or to bring the train back on schedule if it's running early. When they are switched on, the train cannot depart until they are turned off. In 'O' scale, these could be replicated with standard-sized orange LEDs.