This paper presents the procedures and results of a simulation project of a railroad coal transportation system. Locomotives and wagons are modeled at the system level, as opposed to other work that inserts trains at start of the line, and removes them on the other side, just to analyze line utilization and traffic. The case was based on the Estrada de Ferro VitóriaMinas (EFVM), managed by Companhia Vale do Rio Doce, one of the biggest iron coal mining companies in the world. The project helped to find the best train size, the impact of various changes on the physical line, the influence of failures and accidents, and provided a full customized interface, with the ability to do many more experiments.