A fixed frame has upper, lower, and lateral bars in a vertical frame. A movable frame has inner, outer, and side bars in a horizontal plane. The movable frame includes forward, rearward, and side panels. Hinges pivotably couple the side panels to the side bars allowing movement between a horizontal lowered orientation for loading and unloading cargo and a horizontal raised orientation for transporting cargo. Motion imparting mechanisms couple the movable frame with respect to the fixed frame for moving the movable frame between the lowered and raised orientations.