It fits inside the container. It will not go through the door.

A piece 2,650 mm tall fits inside a 40 ft high cube with 48 mm to spare. It will still be sitting on the quay at the end of the day, because the door it has to pass through is 2,585 mm. Nothing was measured wrong. The wrong number was measured.

The number in the table is not the number that matters

Every container specification you will find — ours included — leads with internal length, width and height. Those are the right figures for working out how much fits, and they are the wrong figures for working out whether a given piece can get in.

Cargo does not materialise inside the box. It passes through an aperture at one end, and that aperture is smaller than the space behind it. The door header and sill eat the height; the corner posts eat the width.

Width behaves the same way but hurts less: 2,352 mm inside against a 2,340 mm door, so about 12 mm goes. It is the height that strands machinery.

Figures as published by Hapag-Lloyd (20 ft and 40 ft standard) and OOCL (40 ft high cube). Both carriers state that specifications vary by manufacturer, which is the whole point of the warning further down.

Who this catches

Nobody shipping cartons. This is a problem for exactly three kinds of load, and it is expensive every time.

A single tall indivisible piece. A tank, a transformer, a press, a mine or tunnel fan on its legs. Its height gets checked against the container's internal height, it clears, and the checking stops. The piece arrives at the yard and does not go in.

A top tier stacked to the roof. The stack is legal on paper against internal height. Then the forklift has to carry it through an opening 113 mm lower than the roof it was planned against, and the last few positions by the door will not take the full stack height.

The forklift itself. Even where the load passes, the mast has to get in with it. A counterbalance truck with a standard mast is taller than the aperture with the forks at any useful height, which is why container work uses free-lift or reach masts. If the plan assumes a machine that cannot physically enter the box, the plan has a hole in it that no amount of measuring the cargo will find.

The trick that sometimes works, and the arithmetic that tells you when

The standard answer to a piece a few centimetres over the door is: tilt it, walk it in on a slant, stand it up inside. Sometimes that works. Usually it does not, and the reason is a piece of geometry worth carrying around.

While you rotate a rectangular piece upright about its bottom edge, its highest point does not travel from the door height up to its own height. It travels through its diagonal, because at one moment in the swing the diagonal is vertical. So the condition is not that the piece fits inside. It is that the diagonal fits inside.

√(height² + depth²)  ≤  internal height

Run it on the piece from the opening line. It is 2,650 mm tall and 1,000 mm deep, going into a high cube with 2,698 mm inside:

√(2,650² + 1,000²) = 2,832 mm  >  2,698 mm

It cannot be stood up in there. Not with more people, not with better rigging. The box is not tall enough for the piece to pass through its own diagonal.

Turn the formula round and it tells you the window you actually have. For a high cube, a piece that is over the 2,585 mm door has to be under 2,698 mm to fit at all, and its depth must be no more than:

depth ≤ √(2,698² − height²)

At 2,600 mm tall that allows 721 mm of depth. At 2,650 mm it allows 507 mm. The window is real but narrow: it is for tall thin things — a cabinet, a panel, a mast, a stack of frames — and not for anything with body to it.

The figures above are examples, not guarantees

This is the part that matters most and gets read least. Container dimensions are not standardised to the millimetre. ISO 668 fixes the external envelope so the boxes stack and lock the world over; what happens inside depends on the manufacturer, the wall construction, the year, and whether the box has been repaired.

Both carriers quoted above say so themselves, in the small print under their own tables. A door aperture on an older or repaired box can sit several centimetres off the published figure, and it only ever goes one way.

So: for a piece with less than about 50 mm of margin, no table is an answer. The authority is the CSC plate on the door and, better, a tape measure held against the actual aperture of the actual container that has been allocated to you. Ask for the unit number and have it measured before the piece leaves the works, not after it reaches the port.

When it does not fit

1. Open top. Same footprint, roof comes off, the piece goes in from above with a crane. The door is no longer the constraint — but it is still a container, so the piece must sit within the internal height once the tarpaulin goes back, or it becomes out-of-gauge.
2. Flat rack or platform. No walls, no roof, no aperture at all. Out-of-gauge charges, but the piece travels.
3. Break it down. Legs off the fan, skid off the frame, the piece shipped in two lifts. Usually cheaper than every alternative and usually the last thing anyone considers.
4. Change the leg. A road move on a step-frame or low-loader has a different ceiling entirely, and for a short haul it can beat a special-equipment sea booking.

Before you book

1. Measure the tallest single piece, not the average. One item decides this.
2. Compare it against the door figure in the table above, not the internal height.
3. If it is between the two, run the diagonal before anyone promises a date.
4. If the margin is under 50 mm either way, measure the real box.
5. Then plan the fill. The pallets per container calculator works out the pattern, the second tier and the payload ceiling; the mixed load calculator handles a set of different pieces and flags the ones that need placing rather than stacking.

The door has been in the same place since 1968. It is simply not in the table people read.