Gravity Rack Gravity roadway side of the shelf to use as storage, as the out side of roadway, drum line inclined at an angle on the fixed beams on shelves, pallets Add from the high-end, by itself along the lines of gravity roller down, for the control to stabilize the rate of decline in tray to avoid the collision, in-line roller set at a certain distance of a damping system, the faster the tray down, the damping system to produce greater resistance.