Abstract: A mobile line guard apparatus including a movable platform and an articulating support arm mounted to the movable platform. The support arm being upwardly extendable from a stowed position to a height above the movable platform. The support arm can include at least one arm segment and at least one arm actuator positioned between the platform and the arm segment to extend the support arm upwardly from the stowed position. An articulating guard structure can be pivotably coupled to a distal end portion of the support arm. The guard structure can include a base portion, a horizontal beam rotatably coupled to the base portion, a pair of guide rods, each extending at an angle from opposite ends of the horizontal beam, and a guard actuator positioned between the base portion and the distal end portion of the support arm to angle the guard structure with respect the support arm.