Pallet Containment

For each loaded pallet, LOP calculates the level the load holds unwrapped — standing on its own deck with nothing around it — the levels its transport demands, where containment (stretch film, straps) is needed, and the test that would show that the containment holds. It is a calculation, never a test result or a certification.

Opening the Line

1. Right-click a pallet in the Items Panel or viewport → select "Containment (calculated)"
2. The panel shows what the load holds unwrapped, its transport, where containment is needed and the test that would show it

When you edit a saved pallet, the Edit Pallet panel shows the same line in one row. The PDF prints it in the Pallet loads: containment (calculated) section.

What Is Calculated

• Unwrapped. The level at which the first carton moves, as a horizontal acceleration per 1 g vertical. A carton slides when the acceleration exceeds the friction factor, and tips when it reaches its column's lever ratio b / h: the distance from the column's centre of gravity to the edge of its support, over the height of that centre of gravity (CTU Code Annex 7, 4.3.1). At exactly that ratio the carton tips. The cartons are rigid, at the plan's weights and sizes, judged with the same support, column and lever model as the container's securing plan.
• Friction. 0.5 when every item on the pallet has its Packaging set to Corrugated carton and the pallet is wood (CTU Code Annex 7, Appendix 2: cardboard on cardboard and on a wooden pallet). Otherwise 0.3, the Code's value when a pair is missing or not verified (2.2.2.3). The panel and the PDF print the value used.
• The transport. The CTU Code's accelerations (chapter 5) for the modes the pallet's container is judged under — the same modes as its securing plan, including a transport declared on the plan — per direction, turned with the pallet. A pallet not yet in a container is shown against road, which every transport includes. Air is not covered by the Code.
• Where containment is needed. Each case in which a carton would move. Under road braking (0.8 g) every load needs it, because no friction factor here exceeds 0.5.
• The demand. At the most demanding case, the force against sliding on the deck that film and straps must carry: F = m g (c_h − μ c_v), with m the cargo on the pallet. When the cartons tip before they slide there, the demand is a tipping moment, which only a test shows.
• The test that would show it. An acceleration test (EUMOS 40509) at the case's level, or the inclination test of the CTU Code (Annex 7, Appendix 5) at the angle α for which sin α − γ cos α = c_h − γ c_v, with γ the level the load holds unwrapped in that direction. The most demanding case is the one with the greatest angle.

Printed figures round toward the demand: the holding level down to 0.01 g, the test level and the force up, the angle up to 0.1°.

What Is Not Calculated

What stretch film and straps hold is not calculated. No maker publishes what a layer of film or a strap restrains, and the EU Best Practice Guidelines on cargo securing for road transport (2014, 3.2.2) say that the forces between film or straps and the load cannot be calculated. So LOP gives no number of film layers or straps: only a test on the actual load shows whether its containment holds.

Earlier versions listed wrap, strapping and top-sheet counts from the pallet's weight and height, and a 0–100 stability score. Both are retired: no calculation or test could confirm the counts, and the score ranked loads in the opposite order to an outside rigid-body check (most of the loads it rated "stable" moved below 0.5 g unwrapped).

Next Steps

• Packing Patterns — choose how the layers are built
• Layer Rotation — add cross-layer interlocking
• AI Analysis — get AI-powered explanations of your pallet arrangement