Abstract: A carriage assembly is shown for moving equipment for testing or other functions along a wall surface. The carriage assembly includes a main frame for supporting the equipment in relationship to other equipment and to the wall surface, and a sub-frame that supports service lines such as wires and hoses, while isolating loads created by moving the service lines with the carriage from the main frame and the mounted equipment and providing an unobstructed field of view of the subject area under examination. Wheels mounted on the carriage assembly for providing the interface with the wall surface include fixed position wheels and adjustable wheels to compensate for irregularities along the wall surface. At least one of the fixed position wheels or the adjustable wheels are magnetic for holding the carriage against a ferrous or magnetic wall surface.