The combustion of zero-emission fuels such as hydrogen and ammonia is one of the key directions in the search for alternatives to fossil fuels. Co-combustion of these fuels is possible through the use of a two-stage combustion system. This article presents the methodology for fuel preparation and the design of fuel supply systems for an internal combustion engine intended for railway traction applications. The physicochemical properties of hydrogen and ammonia are discussed, along with their combustion potential in a TJI-type engine. Methods for storage and supply of hydrogen and ammonia to the engine are presented, and a review of flow meters suitable for these fuels is provided, including limitations resulting from their specific properties. Approaches for preparing hydrogen-ammonia mixtures for combustion studies are described, including the determination of air demand for various H₂ + NH₃ mixture compositions. The article concludes with an analysis of typical emission levels of nitrogen oxides and ammonia for different ammonia combustion strategies and for ammonia-hydrogen co-combustion.