Gravity racking, also known as self-gravity racking or roller racking, belongs to a kind of heavy-duty racking, evolved from pallet racking. It mainly consists of columns, beams and roller track (or bottom wheel pallet), the track is a certain slope (usually 3 °~ 5 °) tilt mounted on the beams, the formation of a certain slope of the chute. Each chute can store a number of goods, storage, goods by forklift and other handling equipment into the high end, under the action of gravity, the goods along the chute automatically to the low end of the slide, until the end of the warehouse, to achieve the first-in-first-out storage mode. This kind of shelf is especially suitable for the storage of few varieties and large quantities of the same kind of goods, and the space utilization rate is very high.