Loading a 40ft reefer with pork

A 40ft high-cube reefer takes pallets two abreast and no more, and how many rows fit behind them is set by the internal length of the unit you were quoted. The rest follows from two facts: the T-floor and the return-air path have to stay clear, and the machine holds temperature rather than creating it.

Start with the box you have actually been quoted

ISO 668 classifies series 1 freight containers by their external dimensions and ratings. It does not tell you what is left inside a reefer: insulated walls, roof and doors take width and height, the machinery occupies the front, and the figures move between builders, insulation specifications and unit generations.

Two rules follow:

• Take internal length, width and height — and the stow height to the load line, which is lower than the internal height — from the carrier's specification for the unit type quoted, and check them on arrival.
• Take the weights from the box, not from a table. An approved container carries a CSC safety approval plate with its technical data, required by the International Convention for Safe Containers (CSC, 1972), and the maximum gross mass and tare are marked on the container; payload is the difference. SOLAS chapter VI regulation 2, in force since 1 July 2016, separately makes a shipper-declared verified gross mass a condition of loading a packed container aboard.

Two pallet footprints, one hard width limit

Two of the flat-pallet plan sizes in ISO 6780 carry almost all European boxed meat.

Width is the binding constraint. Two 1,200 mm pallet edges side by side come to 2,400 mm, and three 800 mm edges to the same 2,400 mm; no 40ft reefer has that much clear width inside. Both footprints load two abreast with the 1,200 mm dimension fore and aft, and rows are internal length divided by 1,200 mm, rounded down.

A straight pattern therefore gives the same pallet count either way, but the industrial pallet carries 25% more deck area: two euro pallets use 1,600 mm of the width, two industrial pallets 2,000 mm. Choose the pallet for the destination's handling and racked storage as much as for the container.

Carton dimensions drive the pallet pattern

Transport packaging is built on a 600 × 400 mm base module (ISO 3394), which is why carton size, not pallet size, is the decision that matters:

• Four 600 × 400 mm footprints cover a 1,200 × 800 mm pallet exactly.
• Five cover a 1,200 × 1,000 mm pallet exactly — two with the 600 mm edge across, three with the 400 mm edge across.

Off-module cartons cost you twice: overhang crushes corners under stack load and pushes the pallet against its neighbour or the container wall, closing the air gap, while under-run leaves voids, wastes cube and lets the stack lean.

The T-floor is a duct, not a floor

The extruded aluminium T-bar floor is an air duct: cold air leaves the unit at the front, runs the channels beneath the cargo towards the doors, passes around and through the stow and returns along the ceiling to the evaporator. Block the channels and the system stops working.

• The stow should cover the floor but must not project beyond the floor T-bars, so the door area still gets cooled — it is the last part of the box the air reaches.
• Do not lay solid sheeting, cardboard, film or slip sheets flat on the floor.
• Do not stow above the red line marked inside the container; above it the return-air path along the roof closes up and the unit cannot hold temperature.
• Keep the fresh-air vent closed. Ventilation is for respiring cargo; meat is one of the standing exceptions among chilled commodities, and for frozen cargo the vents are closed anyway.
• Block or brace the void at the door end so the stow cannot shift in transit.
• Do not pre-cool the empty container except in exceptional circumstances: warm, humid air entering a cold box condenses on the internal surfaces.

Set point is an air temperature, not a product temperature

The controller regulates air, not meat. The unit measures the delivery air leaving it and the return air coming back, and the two are not the same number; agree with the carrier which one the set point is controlled on.

A marine reefer holds temperature rather than pulling it down, so product must already be at the required temperature when it is loaded. Regulation (EC) No 853/2004, Annex III, Section I, Chapter VII requires meat to be chilled to a temperature throughout of not more than 3 °C for offal and 7 °C for other meat, and to attain that temperature before transport and hold it during transport. Narrow derogations under Regulation (EU) 2017/1981 cover whole and part carcases moved before chilling is complete; they do not extend to boxed cuts. For product marketed as quick-frozen, Directive 89/108/EEC requires −18 °C or lower at all points in the product, with brief upward fluctuations of no more than 3 °C during transport.

Ask for the pre-trip inspection (PTI) record, and agree in writing how temperature will be evidenced and who downloads it — before the box departs, not after a claim.

What this means for your order

• Fix the carton footprint first. It decides the pallet pattern, the pallet count and the cube you use, and it is the hardest thing to change once packaging is tooled.
• Run both sums. Pallets × gross weight per pallet against payload, and footprint × rows against floor area. Boxed pork is dense; load to whichever ceiling you reach first.
• Write the cold chain into the contract of carriage: set point, control mode, fresh-air vent closed, PTI record, logger type and download point.
• Check the road leg. Directive 96/53/EC sets the weights a Member State must accept in international traffic: 40 tonnes for a five- or six-axle articulated vehicle or road train, rising to 42 or 44 tonnes by axle configuration on an intermodal leg carrying containers or swap bodies up to 45 feet in total. National limits differ, and a box legal at sea can be overweight on the road.