Operations teams are trained to maximize cube. Finance teams are trained to minimize freight per unit. Both incentives push toward cramming one more pallet tier, one more row of cartons, one more SKU into the last gap before the doors close.
Then the container arrives with crushed cases, shifted pallets, or domino damage — and the claim file opens. Surveyors ask about void fill, blocking, and CTU Code compliance. The carrier denies liability. The "saved" CBM cost more than the air you refused to ship.
Dunnage and void fill are not waste. They are insurance against movement — and sometimes leaving deliberate space (or filling it correctly) is cheaper than chasing perfect utilization.
The cube vs protection tension
Every load plan balances two budgets:
| Budget | What you optimize | Risk when over-optimized |
|---|---|---|
| Cube | CBM filled, freight per unit down | Unsecured voids, crush, shift |
| Protection | Restraint, stability, crush margin | Shipping air at peak rates |
The mistake is treating these as sequential — "fill first, secure later." Securing is part of filling. A void left unaddressed is not free space; it is movement allowance waiting to become damage.
Ocean containers experience longitudinal surge, lateral roll, and vertical bounce. Road and rail legs amplify the same forces. CTU Code expects the stuffing party to pack so cargo does not shift dangerously — liability that sits with the shipper in most bill-of-lading regimes, not the vessel operator.
When extra air (or proper fill) is cheaper than claims
Scenario 1: Partial tier at the top
You can squeeze 14 pallets with a partial fifth tier of light cartons — or ship 13 pallets with a clean single-tier stack and proper top void fill. The fourteenth pallet adds 7% more cube but creates a soft top that collapses in swell.
| Option | Cube util | Claim risk | Typical outcome |
|---|---|---|---|
| 14 pallets + partial tier | ~92% | High | Corner crush, denied claim |
| 13 pallets + honeycomb top fill | ~85% | Low | Clean delivery |
At $6,000 all-in for a transpacific 40GP, sacrificing 7% cube costs roughly $420 in freight efficiency — often less than one retail chargeback or one denied damage claim on high-value SKU.
Scenario 2: Lateral void beside machinery
Steel skids or machinery with 150 mm gaps to the container wall need blocking and void fill, not lash-only restraint. Lashing across empty space compresses until something tears.
Fill options: timber chocks, inflatable airbags, honeycomb panels. Each adds cost and weight — but less than rework at destination or spot replacement freight.
Scenario 3: Mixed-density pallet rows
Heavy industrial pallets beside crushable retail cartons without a separator or buffer transfer shock through the stack. A 100 mm air gap filled with dunnage between rows can prevent domino collapse worth multiples of the dunnage cost.
Dunnage types and when to use them
| Material | Best for | Cube impact | Cost profile |
|---|---|---|---|
| Inflatable airbags | Lateral voids between pallets | Low — fills gap only | Moderate; fast install |
| Honeycomb / cardboard | Top voids, partial tiers | Low to moderate | Low material cost |
| Foam inserts | Fragile SKU corners | Moderate | Higher; reusable in some lanes |
| Timber blocking | Heavy cargo, door-end restraint | Moderate | Labor + material |
| Disposable bracing beams | Door-row security | Moderate | Per-container |
| Kraft / paper dunnage | Light fill, chock | Low | Very low |
Rule: Gaps over 50 mm in crushable freight lanes need positive fill before lashing. Webbing alone does not substitute.
The claims math nobody runs
Damage claims have a long tail:
| Cost layer | Often overlooked |
|---|---|
| Direct product loss | Visible at receiving |
| Inspection and survey | Delays release |
| Rework / repack | Labor at DC |
| Retail chargebacks | OTIF penalties |
| Replacement freight | Spot booking at worst time |
| Relationship cost | Buyer trust |
Compare that stack to the freight cost of 5–10% lower cube utilization on the same sailing. On a $5,500 all-in box, 10% unused cube is ~$550 of freight — one moderate claim can exceed that.
This is not an argument for shipping half-empty containers. It is an argument for planned voids with proper fill instead of accidental voids that become movement.
How load planning changes the tradeoff
Software load plans reveal voids before stuffing — when airbags and honeycomb are still cheap to spec. Floor-only planning discovers gaps after pallets are built, when the choice is "add dunnage and miss cutoff" or "lash and hope."
A disciplined workflow:
- Stack in software with stability rules enabled.
- Highlight residual voids above 50 mm in crush lanes.
- Assign fill type per void (airbag, honeycomb, block).
- Add dunnage weight to VGM calculation.
- Compare cube % with and without the risky extra tier — explicit scenario math.
If removing one pallet tier drops cube from 91% to 84% but eliminates a soft-top failure mode, the lower number is often the profitable one.
Cube targets by cargo type
Not all freight should target the same utilization number:
| Cargo profile | Reasonable cube target | Dunnage priority |
|---|---|---|
| Uniform FMCG cartons | 85–92% | Lateral airbags, top fill on partial tiers |
| Mixed light/heavy pallets | 80–88% | Row separators, COG checks |
| Machinery / steel | 70–85% (weight-limited) | Blocking, friction mats, lash |
| High-value fragile | 75–85% | Corner protection, reduced stack height |
| Double-stacked light cartons | 88–94% if crush-tested | Top tier restraint critical |
Chasing 95%+ on mixed profiles without engineering review is a claims strategy, not a loading strategy.
Peak season amplifies the stakes
When Emergency Fuel Surcharges and elevated base rates make every CBM expensive — as of August 21, 2026 — teams feel extra pressure to cram. The same week, terminals compress cutoffs and drayage queues reduce time for last-minute dunnage runs.
As of August 21, 2026. Not customs or legal advice. Tariff exposure on landed cost is independent of dunnage choices — but replacement freight on a claim shipment pays current duty and fuel stacks again. A denied claim can mean paying twice at peak rates.
Pre-spec dunnage in the load plan during plan freeze, not at the container door. Warehouse should stage airbags and honeycomb with the pallets, sequenced for the stuffing crew.
Documentation wins disputes
When claims happen anyway, photos and plans matter:
- Four-corner photos before seal
- Door-row blocking visible in frame
- Load plan showing fill locations
- Packing list matching physical layout
Carriers and insurers deny claims when surveys show inadequate securing. "We filled the container" is not a defense. "We filled void X with rated airbag Y per plan Z" is.
Where Palletizr fits
Palletizr shows where voids will exist before the first forklift move — so you choose between adding a pallet tier and adding dunnage with eyes open. Compare a max-cube plan against a secured plan with fill weight included. The calculator makes the cube-vs-claims tradeoff visible in CBM and pallet count, not just gut feel.
Plan voids and dunnage before stuffing at palletizr.com.
Bottom line
Perfect cube utilization is not perfect economics when movement causes damage. Dunnage and void fill cost money and weight — but less than claims, chargebacks, and replacement freight at peak rates. Build load plans that identify voids early, fill or remove them deliberately, and compare the freight cost of shipping a little air against the full cost of a shifted load. Sometimes the cheaper container is the one that breathes.