in this particular embodiment the horizontal rails 520 are positioned relative to the vertical rails 510 so as to define a shape which has substantially the same dimensions as the stabilizing rib 140 specifically shown here the stabilizing rib 140 is a rectangle which fits within another rectangle created by the horizontal rails 520 and vertical rails 510 of course the stabilizing rib 140 could take on many shapes and sizes while all that is necessary here would be to have features on the wheeled apparatus 500 which correspond with the stabilizing rib fig1 is a side view of an exemplary embodiment of the wheeled apparatus 500 shown in fig1 a plate 580 may extend from the bottom of the wheeled apparatus 500 and preferably sized to fit within the notch 160 at the bottom of the container 403 of course the wheeled apparatus 500 preferably contains some type of rolling means such as wheels 575 these are known in many shapes sizes and designs but will not be further described herein as any means for rolling the apparatus 500 would work with the exemplary embodiments herein fig1 a 13c are side views of the wheeled apparatus 500 of fig1 engaging with the container 403 of fig6 and 7 fig1 a shows the apparatus 550 just before starting to engage with the container 403.