The Common pressure Rail or CPR can be seen as a hydraulic equivalent of the electricity grid. It is easy to attach and add different loads to the power grid. The common pressure rail separates the hydraulic power plants (the pumps) from the loads (motors and cylinders). Loads do not influence each other. By means of hydro pneumatic accumulators the pressure level of the common pressure rail can be varied in a controlled way. The energy that is stored in these accumulators can be used for power management and energy recuperation. The pressure does not necessarily have to be constant, as Hydraulic Transformers are used as control devices. The transformers can transform hydraulic energy almost without energy loss. CPR technology enables a much simpler and more flexible ‘plug-and-play’ approach of hydraulic circuits, in analogy to the ease of use of an electricity grid. In mobile applications a Chiron Free Piston Engine can be used as power source for a CPR.