Abstract: The present invention provides an apparatus for mounting an appliance at an opening in a wall, particularly for use with openings in the exterior walls of storage tanks and the like. The apparatus allows men and materials to be safely raised and lowered within the opening, can be moved away from the opening without completely removing the apparatus from the tank, and can be used to mount a variety or different appliances for use through the opening. The apparatus comprises grasping clamps for securing the apparatus to the opening of the wall, an appliance mounting member for connecting an appliance to the grasping clamps, and an appliance for maneuvering through the opening and performing a predetermined task within the tank.