invention without departing from the spirit thereof referring now to fig3 a schematic diagram of an electric drive and control system 100 for the vibratory roller machine of fig1 and 2 is provided powered components of the machine 10 including the exciter assemblies and drive assemblies of the drum assemblies 12 and 14 may be driven by the engine 22 the electric drive and control system 100 may be a series hybrid drive system as described above with respect to fig1 and u s pat no 8 585 317 to sina the entirety of which is hereby expressly incorporated by reference the electric drive and control system 100 may include the aforementioned engine 22 generator 26 power storage system 58 and a starter 104 operation of and power transfer between the engine 22 the generator 26 and the power storage system 58 and the powered components of the machine 10 including the first and second front drive motors 64 a and 64 b the first and second rear drive motors 66 a and 66 b the first and second front brakes 70 a and 70 b the first and second rear brakes 72 a and 72 b and the front and rear vibration exciters 74 and 76 are.