Case Study: 12 SKUs in One 40HQ Container

The brief arrived on a Tuesday with a sailing date eleven days out. Twelve SKUs of filters and brake components, one 40HQ, delivery to a single distribution centre in northern Poland.

On paper it was a comfortable fit: 58 cubic metres of goods against a 40HQ's usable 67.5. The loading plan we drew on Wednesday showed the container closing with four pallets still on the dock.

The Brief: Twelve SKUs, One Container, Fixed Sailing Date

The distributor had consolidated four suppliers into one shipment to hit a promotional window. Missing the sailing date meant missing the window, and the window was worth more than the freight saving.

Constraints were tight and specific. No SKU could be split across two pallets, because the destination warehouse counted by pallet. The heaviest SKU could not go on top of anything softer than itself.

There was also a documentation constraint. Customs needed each SKU listed separately with its own HS code, which ruled out repacking loose cartons into a mixed pallet under a single line.

What the Volume Calculation Actually Showed

The first calculation summed carton volumes and divided by container capacity. That number is necessary and insufficient, because it ignores the two dimensions that actually bind: floor area and stackability.

Thirty pallets, of which only the cabin filters could safely take a second tier. The brake discs were heavy and flat-packed, and stacking them above 0.9 m risked deformation at the hub face.

A 40HQ takes 20 standard pallets on the floor, or 21 with a mixed pattern. Thirty pallets in a single tier was never going to close, regardless of what the cubic metre figure said.

Loading Plan and the Failure We Avoided

The fix was a two-tier plan restricted to the families that could actually bear load, combined with a carton-level reconfiguration for the two low-stack families.

• Cabin filters stacked two high on Euro pallets: 8 pallets became 4 positions, 3.4 m of stack.
• Oil filters rebuilt onto 1.2 m pallets at 1.6 m stack: 12 pallets became 8 positions.
• Brake pads and discs kept single tier, but re-slotted into the nose and against the side walls.
• Two pallets converted to carton-floor loading at the door end, braced with inflatable dunnage.

That brought the plan to 18 pallet positions plus a carton block, which left a 1.1 m walkway for the stevedores and a load-bearing path along the container spine.

The failure we avoided was not the obvious one. Had we loaded to the volume figure, the last four pallets would have gone in by force, and the brake discs at the door would have taken the shifting load of everything behind them.

Weight distribution mattered as much as count. Loading 19.2 tonnes with 62% of mass forward of centre is legal, but it produces a container that handles badly on a road leg and can attract a weight-distribution query at a European weighbridge.

Results and What Changed Afterwards

The container closed with 96% floor utilisation and 88% volume utilisation, and it sailed on the booked date.

Two changes became standard practice after this shipment. First, every quotation now states the pallet type and stack height the price assumes, so the loading plan is designed at quoting time rather than at booking time.

Second, the destination warehouse now accepts SKUs split across pallets when the split is declared on the packing list. That single concession removed the constraint that made this container hard in the first place.

The distributor reported a clean receiving audit and rebooked the same twelve SKUs for the following quarter, at 14% lower freight per unit because the consolidation pattern was already proven.

What this shipment demonstrated is narrower than a general claim about auto parts container consolidation. The technique worked because the part families had known stack limits and the SKU count was small enough to plan by hand.

Scale it to forty SKUs and the same approach breaks down, which is why we now cap mixed auto parts container consolidation at twenty-five SKUs per sailing. Beyond that point the loading plan needs software, and the risk of a wrong count outweighs the freight saving.

For a distributor planning a first auto parts container consolidation, the practical lesson is to design the plan before the booking rather than after the goods are ready. Booking first turns a design problem into a negotiation with a stevedore.

Frequently Asked Questions

How many pallets fit in a 40HQ?

Twenty standard 1200x1000 pallets in a single tier, or 21 with a mixed pattern. Euro pallets allow 24 to 25 in a single tier. These figures assume no carton-floor loading and a clean rectangular stack.

Is it better to load loose cartons or pallets?

Pallets load and unload faster and protect goods better. Carton-floor loading recovers 8% to 12% of cube and is worth considering only when the shipment is cube-limited rather than floor-limited.

Does stack height affect freight cost?

Indirectly. Stack height determines how many pallet positions you need, and pallet positions determine whether the container closes. A 10 cm reduction in stack height across a full container can free up two positions.

Who should design the loading plan?

The party that knows the packaging and the part strength, which is normally the supplier, reviewed by the consolidator who knows the container. A plan designed only at the destination is a plan designed without the goods.

Reference Sources

ISO 668:2020 — Series 1 freight containers, classification and dimensions.

ISO 1496-1 — Specification and testing of general cargo containers.

EN 13698-1 — Pallet production specification, 800x1200 mm.

ISTA 3E — Unitized loads of similar products for truck and rail.

CTU Code 2014 — IMO/ILO/UNECE Code of Practice for Packing of Cargo Transport Units.