This storage solution follows the LIFO pattern (Last-In, First-Out) meaning that the last pallet introduced into the racking is the first that can be removed.
With this solution, the operator has to push back the pallets stored with the handling equipment, to make room for the new pallet to be stored on the racking.
For unloading the pallets, the push-back system works like a pallet live storage system. When the pallet at the picking face is removed, the next pallet falls by gravity in a controlled manner by means of brakes, and positions itself on the picking face ready to be retrieved.
Attending the moving part and the way the pallets are stored in the depth, there are two possible technical solutions:
- Push back on rollers: pallets move on roller conveyors, and
- Push back on platforms: the load units rest on wheeled platforms that move back and forward pushed by the lift truck.
From a constructive perspective, the racking structure is quite similar to a pallet live storage system, in which either platforms or alternatively roller sets rest on the racking beams to achieve the necessary slope (3 – 4%) which permits subsequent gravity displacements of the load units.