A mobile hydraulic fracturing fluid delivery system for pumping high pressure fracturing fluid into an underground well bore at a well site and being transportable between multiple well sites, the mobile hydraulic fracturing fluid delivery system comprising: a chassis, said chassis being configured to be transportable between well sites; an electric motor disposed upon said chassis, said electric motor being electrically coupled to an external electric power source and having first and second opposing ends (38, 40), said electric motor further having a single drive shaft extending axially therethrough and outwardly therefrom at said first and second opposing ends (38, 40) thereof; a first fluid pump disposed upon said chassis, directly coupled to said drive shaft of said electric motor at said first end of said motor and configured to pump fracturing fluid into the well bore; a second fluid pump disposed upon said chassis, directly coupled to said drive shaft of said electric motor at said second end of said motor and configured to pump fracturing fluid into the well bore at the same time as said first fluid pump, wherein said first and second fluid pumps (50, 60) are axially aligned with said electric motor at said opposing ends (38, 40) thereof, further wherein said drive shaft of said electric motor is coupled to said first and second fluid pumps (50, 60) so that said electric motor is capable of concurrently driving both said fluid pumps (50, 60) and said electric motor is configured to drive each said fluid pump (50, 60) regardless of the operation of said other fluid pump (50, 60), further wherein said first and second fluid pumps (50, 60) are coupled to said drive shaft of said electric motor with all their respective piston top-dead-center positions out of phase; at least a first flex coupling engaged with and between said electric motor and said first fluid pump and configured to allow movement of said electric motor and said first fluid pump relative to one another during and without disturbing the operation thereof; and at least a second flex coupling engaged with and between said electric motor and said second fluid pump and configured to allow movement of said electric motor and said second fluid pump relative to one another during and without disturbing the operation thereof. a chassis, said chassis being configured to be transportable between well sites; an electric motor disposed upon said chassis, said electric motor being electrically coupled to an external electric power source and having first and second opposing ends (38, 40), said electric motor further having a single drive shaft extending axially therethrough and outwardly therefrom at said first and second opposing ends (38, 40) thereof; a first fluid pump disposed upon said chassis, directly coupled to said drive shaft of said electric motor at said first end of said motor and configured to pump fracturing fluid into the well bore; a second fluid pump disposed upon said chassis, directly coupled to said drive shaft of said electric motor at said second end of said motor and configured to pump fracturing fluid into the well bore at the same time as said first fluid pump, wherein said first and second fluid pumps (50, 60) are axially aligned with said electric motor at said opposing ends (38, 40) thereof, further wherein said drive shaft of said electric motor is coupled to said first and second fluid pumps (50, 60) so that said electric motor is capable of concurrently driving both said fluid pumps (50, 60) and said electric motor is configured to drive each said fluid pump (50, 60) regardless of the operation of said other fluid pump (50, 60), further wherein said first and second fluid pumps (50, 60) are coupled to said drive shaft of said electric motor with all their respective piston top-dead-center positions out of phase; at least a first flex coupling engaged with and between said electric motor and said first fluid pump and configured to allow movement of said electric motor and said first fluid pump relative to one another during and without disturbing the operation thereof; and at least a second flex coupling engaged with and between said electric motor and said second fluid pump and configured to allow movement of said electric motor and said second fluid pump relative to one another during and without disturbing the operation thereof.