Powertrains for heavy equipment are not well suited nor feasible to electrify within acceptable timeframes. For these applications the combustion engine, running on sustainable fuels like hydrogen and methanol is a very attractive solution. Combining mature and robust engine technology with dedicated technology for these new fuels enables to accelerate the CO2 reduction for these challenging powertrains. Even more so, by use of advanced combustion concepts, there is also the potential for these engines to have ultra-low pollutant emissions, eliminating the need for costly aftertreatment. The contents of work at TNO span a wide range of topics: engine modelling on fuel injection, combustion and aftertreatment, development of engine scaling methodologies for large maritime engines and feasibility studies. Type of work is both numerical as well as experimental data analysis. Affinity and knowledge on combustion engines and thermodynamics is required. Experience with Matlab® and Matlab-Simulink® is highly recommended.