Double-deep racking is created by placing one row of
selective rack behind another. The result is racking that’s
twice as deep as selective racking. In most cases, two
pallets with the same product are stored in a slot, and
a deep-reach lift truck or a lift truck with a double-deep
handling attachment is required to access loads in the
rear position.
While double-deep racking looks like selective racking,
it is actually considered a type of high-density racking.
High-density racking helps users optimize warehouse
cube use by allowing more pallets to be stored per cubic
foot. However, it is not as flexible as selective racking,
and pallets are not as accessible. For example, in a
double-deep rack, workers cannot access the rear pallet
unless the front pallet position is empty.
BENEFITS:
b Cost per pallet position is lower than
with other high-density options
b Increases the productive use of
floor space by 60 to 65 percent over
selective racking
APPLICATIONS:
b Facilities that require high-density
storage
b Last-in, first-out inventory operations.
Double-deep racking is not as suitable for first-in, first-out inventory management, as that would require double
handling of pallets (removing the front pallet in order to
access the back pallet).
DOUBLE-DEEP RACK
In this type of high-density rack, pallet loads are placed
at the end of a series of rollers or skate wheels and then
flow down an incline to be picked at the opposite end.
As a result, they are a first-in, first-out storage solution.
Typically, there is a nylon or metal stop at the end to keep
the pallets in the bay.
BENEFITS:
b No limit to how deep you can go. Pallet flow racks that
are equipped with a brake system have been known to
go 20 pallets deep.
b Maximizes space by eliminating aisles
and storing pallets in lanes
APPLICATIONS:
b Works well in deeper systems
b Can be used for pick modules
and staging areas
b Works well when you have a large
volume per SKU
b Good for high-throughput operations and
for managing perishable and time-sensitive products
PALLET FLOW/GRAVITY FLOW RACK
In pushback pallet rack systems, the pallet is placed on a
series of nesting carts that glide on rails. New pallets are
stored by pushing back the previously loaded
pallets and placing the new load in the
next cart position. Typically, pallets are
stored two to six deep. When a pallet is
retrieved, the next pallet drops forward
into the ready position. As a result,
pushback racks operate according to
a “last-in, first-out” principle. Pushback
racks do not require the use of any type of
specialized lift trucks.
BENEFITS:
b Provides similar storage density to drive-in racking
but with better selectivity and accessibility to a range of
SKUs
b Reduces picking time when a large number of pick
faces are required
b Provides higher utilization of available pallet positions
than most storage systems do
b Requires fewer aisles than selective racking does
b Faster to load or unload than drive-in racks are
APPLICATIONS:
b Operations that have a large number of SKUs and
need a lot of pick faces
b Bulk storage
b Operations that store several products in quantities of
more than five pallets per SKU
PUSHBACK RACK
