Abstract: An improvement to a semi-autonomous apparatus is described herein. In an apparatus having a gantry subassembly, a tram subassembly movably mounted on the gantry subassembly, and an actuation subassembly mounted on the tram subassembly, the improvement includes a gripper subassembly operatively connected to the actuation subassembly. The movement of the subassemblies is controlled in part by a control system that controls drive systems associated with one or more of the subassemblies. The gantry subassembly includes a bridge member for laterally spanning a selected section of a work site. The tram subassembly includes a tram that travels laterally along to the bridge member. The actuation subassembly includes at least one motion actuator for controlling the movement of the gripper subassembly in a generally vertical direction and may include an additional motion actuator for movement in a generally horizontal direction.