Coal-firing
In the 1940s and 1950s research was done, in both the USA and UK, aimed at building gas turbine locomotives which could run on pulverized coal. The main problem was to avoid erosion of the turbine blades by particles of ash. Some bench testing was done but the projects were abandoned before any complete locomotives were built. The sources for the following information are Robertson and Sampson.
Read more about this topic: Gas Turbine Locomotive