To develop, build, test, demonstrate and homologate a scalable, modular and multi-purpose Fuel Cell Hybrid PowerPack (FCHPP) applicable for different rail applications (multiple unit, mainline and shunting locomotives) also suitable to for retrofit existing electric and diesel trains, to reach TRL7. The project will start with a multi-country, multi railway-use-case analysis in order to derive requirements for the design, implementation and test of the FCHPP. Based on that the FCHPP will be designed and demonstrated in a retrofitted Bi-mode multiple unit that draws electricity from the catenary while operating on electrified sections and uses the FCH system as power source on non-electrified sections supported by an innovative train wide energy management system to minimise the energy and power consumption.