There is disclosed a hydrogen powered internal combustion engine (12) having cylinders (22) for driving crankshafts (28). The crankshafts are configured to drive water pumps (32) which are for pumping water into engagement with drive faces (58) of a drive water wheel (44). This water wheel is connected to, and drives, a main propulsion shaft (30) which produces the main propulsion of the engine, for example, for powering a vehicle. One or more ancillary water wheels (46, 48) are driven by the pumped water and are connected to generators for producing electric current for powering an electrolysis device (78) which produces hydrogen that can be used as fuel by the engine.