Double Stack Feasibility
Check whether pallets can be safely double-stacked in a trailer on both height and weight, and the resulting trailer cube utilization gain.
Two pallets at 58 inches each exceed the 110 inch clear height.
How this works
Double-stacking is feasible only when two separate checks both clear: the trailer's clear height has to fit two pallets stacked, and the trailer's total legal weight limit has to hold every floor position loaded that way, since the weight limit is trailer-wide, not a per-pallet figure. Whichever check fails first is reported as the binding constraint. When feasible, the cube utilization gain equals exactly the single-stack height's share of the clear-height limit, since double-stacking uses precisely twice the height at the same floor footprint.
Key terms
- Trailer clear height: the trailer's interior clear height from floor to ceiling.
- Binding constraint: whichever check, height or weight, fails first and blocks double-stacking.
- Cube utilization gain: the increase in the trailer's height actually used by double-stacking versus single-stacking.
Assumptions
- Uniform pallet height and weight across the shipment
- The weight check is against the trailer's total legal weight limit
Limitations
- Does not check the bottom pallet's structural crush or compression strength, a separate engineering rating from the trailer's legal weight limit
- Does not model partial double-stacking where some positions are stacked and others are not
Sources
Standard freight loading and unit-load treatment (Frazelle's World-Class Warehousing and Material Handling, Tompkins et al.'s Facilities Planning), the same floor-and-cap discipline used in Cartons per Pallet Optimizer and Pallet Height Optimizer.
Worked example
A 50 inch pallet stacked two-high is 100 inches, well within a 110 inch trailer clear height, so a height-only check would call the load feasible. But at 2,000 pounds per pallet across 26 floor positions, stacking every position two-high puts the trailer at 104,000 pounds, more than double a 44,000 pound legal weight limit. The load is weight-limited, not cube-limited, and only checking height would clear an unsafe, illegal load.
Common use cases
- Checking whether a shipment can double-stack before booking a trailer
- Finding whether height or weight is the real constraint on double-stacking dense freight
- Estimating the trailer cube utilization gain from double-stacking a finished pallet height from Pallet Height Optimizer