Unitization

As outlined in the specifications section of the KnowledgeBase, all package designs should include specifications for secondary packages and unit loads. Please see the table below marked "Maximum Unitload Size by Shipping Mode" for some guidance on likely maximum sizes that should be considered.

Throughout the supply chain there are many opportunities to double stack unitloads. One must assume that they will be double stacked along a route that often takes materials through a series of transportation steps:

Transport Step Likely Special Hazards
Manufacturing Handling, dropping
Distribution Stacking
Truck Vibration, marshalling, stacking
Freight Forwarder Warehouse Stacking, break-down
Airline Pallet Stacking
Trolley Exposure
Aircraft Barometric pressure, ESD, Vibration
Trolley Exposure
Forwarder Warehouse Stacking, break-down
Truck Vibration, marshalling, stacking
Distribution Warehouse Stacking, handling
Carrier to End User. Dropping, piercing, shock, vibration

Obviously, any unit load that can ship through the distribution chain without being broken-down should survive in the best condition.

Unitload Size by Shipping Mode

While there can be a vast difference in preferred unit load sizes, below are some tables that will give the user an insight into the likely maximum sizes that will be encountered.

Maximum Unitload Size by Shipping Mode

Preferred Unit Load Maximum Size - MM

Preferred Unit Load Max - Inch

Shipping Mode

1200mm x 1000mm x 1550mm

47.24" x 39.37" x 61"

 Lower Deck Air Cargo

Single Stack Truck

1200mm x 1000mm x 1225mm

47.24" x 39.37" x 48"

Double Stack Upper

Maximum Unitload Size by Shipping Mode

Recommended Maximum Size - using metric pallet

 

Shipping Mode

1200mm x 1000mm x 1550mm

47.24" x 39.37" x 61"

 Lower Deck Air Cargo

Single Stack Truck

1200mm x 1000mm x 1225mm

47.24" x 39.37" x 48"

 Double Stack Upper Deck Air

Double Stack Truck US

1200mm x 1000mm x 1372mm

47.24" x 37.37" x 54"

 Truck Dimensions US

Lower Deck Air Cargo

Recommended Maximum Size - using imperial pallet

 

 

1219mm x 1016mm x 1550mm

48" x 40" x 61"

 Lower Deck Air Cargo

Single Stack Truck

1219mm x 1016mm x 1225mm

48" x 40" x 48"

 Double Stack Upper Deck Air

Double Stack Truck US

Note: These dimensions are Outside, Maximum Dimensions. A shipping case that is 12" high will only stack 3 layers high on a 48" high Unit Load: 3 x 12 = 36 + 6" pallet + 3/16" slipsheet + 5/16" cap + ½" cumulative tolerances = 43" total height. For a standard unit load configuration the unitizing materials account for 7" (178mm) of additional height.

Truck transport Considerations – The typical trailer for cross country hauls in the U.S. has a 110" (2794mm) vertical clearance. A maximum unitload height of 54" (1372mm) will allow double stacking of loads. Materials that travel by truck and air should be optimized for the most costly leg of the transportation routing – Air Cargo. Trailers in Europe may have lower vertical clearance, and the maximum height should therefore be limited to 48" (1219mm) if double stacking is to be permitted.

*The table above changes with airline schedule and market changes.