Train scheduling is one of the tactical planning of a railway service company. The challenge of railway scheduling is when the type of track that is passed is a partial track double track. If the scheduling is not optimal, will cause the idle time, where the train must wait for the intersection. This research purpose mathematical model for train scheduling problem in partial double track rail line to minimize idle time. We consider three criteria in developing this mathematical model: (1) Coupling/uncoupling wagon to minimize deadhead trip; (2) Fixed block signaling; (3) Rail and station capacity; (4) Meeting and passing in partial double track. To test our model, we used actual data in Indonesian Railway, especially in shout track railway, track from Bandung -Yogyakarta City. Using this mathematical model, our purposed model can minimize total idle time.