Pallet racks can be installed in a double-deep configuration. This provides access to two pallets from the same side of the aisle, with one placed behind the other towards the back of the pallet rack (the illustrations below will give you a better idea of how the load units are arranged).
Although the main advantage of the double-deep system (i.e., the ability to save space due to the need for fewer aisles to access loads) is clear, we should also be aware of its limitations and requirements.
One such limitation is that there is only direct access to the front pallet. To reach the second unit, the first pallet has to be moved, either to its destination (the dispatch area, for example) or to another empty space (in other words, relocate it).
Normal distribution of pallet racks
Double-deep rack distribution.
Where goods are handled using forklift trucks, some models of forklifts have telescopic forks or pantographs which allow access to the second depth.
In automated warehouses, double-deep configurations can also be established thanks to the use of stacker cranes with telescopic forks.
To use double-deep racking, one must anticipate the number of pallets for each item. This method of racking is appropriate if the pallet that is going to be at the back contains the same item as the one in front of it, and perfect rotation is not required.
For facilities with automated machines, the problem of access caused by the use of the double-deep configuration is resolved by the management program and its corresponding relocation module. To determine position, this software takes into account the rotation of the item (A, B, or C) and the quantity of the item in question. The result of this is that although the racking is double-deep, access is almost as good as for single-deep but without losing the benefit of a considerable increase in capacity.
Single-deep racking in a company providing ceramics for the construction sector.
Double-deep racking in the warehouse of a pharmaceuticals company