Pallet flow rack is deep lane rack in which the shelving is slanted and lines with rollers, so that when a pallet is removed, gravity pulls the remainder to the front. This enables pallets to be put-away at one side and retrieved from the other, which prevents storage and retrieval operations from interfering with each other. Because of weight considerations, storage depth is usually limited to about eight pallets. This type of rack is appropriate for high-throughput facilities.
Except for automated storage-and-retrieval systems (AS/RS), some type of lift truck is required to access the loads in pallet rack; and specialized racks may require specialized trucks. The most common type of lift trucks are: