Abstract: Self-contained simplified power apparatus for operating electric transmission line switches locally or remotely includes a rotary hydraulic actuator arranged for mechanical coupling to the line switch, a battery-powered reversible low voltage motor operating a reversible hydraulic pump, with the opposite ports of the pump connected respectively to the opposite ports of the hydraulic actuator for selectively producing closing and opening movements of the hydraulic actuator responsive directly to reversals in the direction of the motor and pump, means for selectively starting, stopping and reversing the motor either from a remote point or locally, and means for disengaging the operator from the line switch to permit manual operation of the latter. For line switches that require high speed closure, a modified embodiment of the invention provides electrically controlled hydraulic means to this end.