Since 1979, the US Department of Energy has been sponsoring Research and Development programs to use coal as a fuel for diesel engines. In 1984, under the partial sponsorship of the Burlington Northern and Norfolk Southern Railroads, GE completed a 30-month study on the economic viability of a coal-fueled locomotive. In response to a GE proposal to continue researching the economic and technical feasibility of a coal-fueled diesel engine for locomotives, DOE awarded a contract to GE Corporate Research and Development for a three-year program that began in March 1985 and was completed in 1988. That program was divided into two parts: an Economic Assessment Study and a Technical Feasibility Study. The Economic Assessment Study evaluated the benefits to be derived from development of a coal-fueled diesel engine. Seven areas and their economic impact on the use of coal-fueled diesels were examined; impact on railroad infrastructure, expected maintenance cost, environmental considerations, impact of higher capital costs, railroad training and crew costs, beneficiated coal costs for viable economics, and future cost of money. The Technical Feasibility Study used laboratory- and bench-scale experiments to investigate the combustion of coal. The major accomplishments of this study were the development of injection hardware for coal water slurry (CWS) fuel, successful testing of CWS fuel in a full-size, single-cylinder, medium-speed diesel engine, evaluation of full-scale engine wear rates with metal and ceramic components, and the characterization of gaseous and particulate emissions. Full combustion of CWS fuel was accomplished at full and part load with reasonable manifold conditions.