Technical guide with sources · ROLL Lab

Packing and shipping paper cores

ROLL Lab · updated 24 October 2026 · sources at the end of the page

Staggered rows: the pitch is not the diameter

If the first row has n cores, the second nests in the hollows and has n − 1. The vertical pitch between two rows is Ø × √3/2 ≈ 0.866 × Ø. Height of k rows = Ø + (k − 1) × 0.866 × Ø. Ten rows of Ø 100 cores stand 879 mm high and hold 55 cores (6+5+6+5…). Getting this sum wrong is the quickest way to promise a pack that will not go through the door.

Overhang: as a fraction of the radius

A core rests on the pallet along its centre line: as long as the contact point stays inside the edge, it is supported. Side overhang is measured as a fraction of the radius: at most half the radius per side. Example: across a 1,200 mm face, Ø 190 cores fit 6 per row, not 7. Lengthwise, a core can overhang by up to 400 mm per side; beyond that, add a second pallet.

Vehicles and the container door

Always allow 20 mm of clearance for lifting and sliding in. In containers the door sets the limit, about 2,200 mm, not the roof. A drawbar combination with two 7.7 m bodies will not take an 8 m core.

Types of pack

• Standard double stack (1+1): two identical pallets stacked, each half the usable height. They are built from the same worksheet.
• Optimised double stack: when the total number of rows is odd, one pallet takes an extra row. On a mega trailer with Ø 100 cores: 334 cores per stack instead of 322.
• Single high pack: one pack only, at most 2,200 mm, the limit beyond which a person cannot load by hand.
• Wide + narrow pair: two real pallets of different depth side by side to fill the width. Ø 178 × 2,000 cores in a 40′ HC container: 942 instead of 864 (+9%).
• Frame: a rigid surround with no overhang for long or in-line cores; two frames per metre of core, stackable.

Cores standing upright

Short cores (under 800 mm) or very wide ones (over 300 mm in diameter) are loaded upright: staggered rows in plan too, layers = available height / length. With an odd number of layers, build two different packs (for example 4+3) rather than give up a layer: on a mega trailer with 360 mm cores the gain is 17%.

What to check separately

The calculation does not know the weight distribution over the axles and does not check that the bottom cores can carry those above: on tall stacks of thin-walled cores this is a real risk. Vehicle payload removes whole packs, not fractions. Try the calculator.

Sources

1. ROLL Lab calculation (packing and loading algorithm, verified with 52 tests and hand-calculated examples)