Book excerpt: With the increasing demands for safer freight trains operating with higher speed and higher loads, it is necessary to implement methods for controlling longer, heavier trains. This requires a full understanding of the factors that affect their dynamic performance. Simulation techniques allow proposed innovations to be optimised before introducing them into the operational railway environment. Coverage is given to the various types of locomotives used with heavy haul freight trains, along with the various possible configurations of those trains. This book serves as an introductory text for college students, and as a reference for engineers practicing in heavy haul rail network design,