The yardmaster’s job in a model railroad is to organize the cars according to the destinations to which they are headed. Once that is done, the yardmaster then has to come up with the order in which the trains have to be sent out. Once that is done, the trains are lined on the departing track. The yardmaster then has to wait for clearance from the dispatcher. Following the clearance from the dispatcher, the train heads towards its destination. Since a regular 24 hour session is compressed to usually a maximum of 4 hours for an operating session, the trains must be on schedule.