1. Determining Pallet Maximum Working Loads From Nominal Load Measurements
Marshall S. White
Wilbur Dibling
Ralph Rupert
John McLeod

2. Most Loads on Pallets do not act Like Airbags or Two Rigid Bars as in Draft ISO 8611-1 Tests 1 and 3

3. Certain Loads on Pallets will “Bridge” across the Pallet Deck
Certain Loads on Pallets will “Bridge” across the Pallet Deck. In Warehouse Racks, Some Loads will Shift Stresses from the Center of the Pallet to the Rack Supports

4. We Tested Different Load Configurations To Determine The Level Of Load Bridging In A Warehouse Rack

5. We Tested The Following Load Stabilizers
Interlock Stacking
Stretch Wrap
Strapping (steel and poly)
Breakaway Adhesive
Pallet Tie Sheets
Stretch tape

7. We Used Plywood To Simulate Pallets And Used 4 Different Stiffness Levels of Pallets
5.3 kN per cm of deflection
3.6 kN per cm of deflection
2.3 kN per cm of deflection
1.6 kN per cm of deflection

9. Each Load Was Lifted 5 Times To Simulate Typical Loosening Of Load After Palletization

10. Case Goods, Average Deflections at 4.5 kN
25.0
Low
20.0
Medium-Low
15.0
Deflection (mm)
10.0
Medium
High
5.0
0.0
Airbag
Column
Stretch Tape
Adhesive
Column,SW
Tie Sheets
Column,ST
Interlock
Interlock,SW
Interlock, ST
Interlock,ST

11. Case Goods, Average Deflections at
4.5 kN, Low Stiffness Panel
0.0
5.0
10.0
15.0
20.0
25.0
Deflection (mm)
Airbag
Column
Stretch Tape
Adhesive
Column,SW
Tie Sheets
Column,ST
Interlock
Interlock, SW ST

13. Sacks, Average Deflections at 4.5kN, Low Stiffness Panel
0.0
5.0
10.0
15.0
20.0
25.0
Deflection (mm)
Airbag
Column
Column, SW ST
Interlock,
Int, Plas
Strp
Interlock

17. The Effect of Load Geometry on Load Bridging
During Warehouse Rack Storage on Pallets

18. The Effect of Load Stabilizers on Load Bridging
During Warehouse Rack Storage
of Cased Goods on Pallets
Average Pallet Deflection as a Percent
of Column Stacked Deflection 20 40 60 80
100
Column
Stacked
Stretch
Tape
Interlock
Pallet
Sheets
Wrap
Adhesive
Strapping
Load Stabilizers
Percent Deflection
100
100 96 94 87 80 61

19. The Effect of Load Stabilizers on Load Bridging
During Warehouse Rack Storage
of Sacked Products on Pallets

20. The Effect of Load Stabilizers on Load Bridging
During Warehouse Rack Storage
of Column Stacked 5 Gallon Pails on Pallets

21. The Effect of Load Stabilizers on Load Bridging
During Warehouse Rack Storage
of 55 Gallon Drums on Pallets

22. Implications of Load Bridging Tests on Estimates of Maximum Working Loads for pallets as described in Draft ISO TS8611-3
Geometry and mechanical properties of the package or container on the pallet affect the maximum working load estimate
The types of load binders used affect the maximum working load estimates
The tension applied to the load binders affects the maximum working load estimates

23. Implications of Load Bridging Tests on Estimates of Maximum Working Loads for pallets as described in Draft ISO TS8611-3
The package or container stacking patterns affect the maximum working load estimate
The stiffness of the pallet affects the maximum working load estimates
Normal movement of the unit load changes unit load stiffness and therefore affects the maximum working load estimates