The box is a structure, not padding
Protective wood packaging for machinery is usually specified as if it were padding: choose a thickness, line it with foam, close the lid. That works for a part that can be dropped. It does not work for a machine, because a machine delivers its whole mass into a small number of points and then asks the box to carry that mass while being lifted, set down, stacked and moved again.
So the question is not how thick the panel is. The question is where the load goes. Six requirements decide that, and each one is a line on the drawing.
Requirement one: the base carries the machine, not the panel
A machine stands on its own frame or feet, and the area through which that mass reaches the floor is small relative to the box. A floor panel designed for a distributed load will dish under a point load, and once it dishes the machine is no longer sitting flat.
The fix is structural rather than material. Bearers go under the machine frame, not under the panel edges, so the mass enters the base structure and is spread from there. Going up a panel thickness instead is the expensive way to solve a load path problem, and it does not solve it.
Requirement two: the box survives being lifted at two corners
Lifting is a different load case from sitting still, and it is the one that breaks crates. A sling or a forklift applied at two corners puts a bending load across the whole box, and a corner that has been nailed on takes that load once.
In a steel-edged construction the lift load enters a folded steel section rather than a nailed timber block. The strip is cold-rolled on the forming machine and pressed onto the panel under hydraulic force — 30 t nominal on the 2.5 m build, with a 2.5 m working width — so the rim is a closed section rather than a panel end with a fixing through it.
Ask for the lifting points to be marked on the drawing. A box that is lifted somewhere other than where it was designed to be lifted is a box that will fail on a route it was never specified for.
Requirement three: the box stays square
Machines have aligned parts: doors, covers, shafts, mounts. A box that racks in transit puts those out of alignment, and the damage is discovered when the machine is commissioned rather than when the box is opened.
Racking comes from two places. A box that is not square when it is built cannot stay square, which is a joint question — buckles driven at a set pitch from a machine-produced panel come out square to the drawing. And a box lifted from a single point racks by design, whatever its joint.
Requirement four: the load does not move inside the box
A box holds the machine in; it does not stop the machine moving inside. That is blocking and bracing, and it is a separate design decision.
Two rules cover most of it. Brace to the base and to structural edges, never to the middle of a panel, because a brace landing mid-panel turns a shock load into a point load on the one part of the box with nothing behind it. And make sure the bracing can be reached and removed with the lid off, because bracing that cannot be reached gets improvised on site.
Requirement five: moisture is controlled, not sealed out
No wooden box is a sealed container, and a box sealed tightly enough to keep rain out will also hold the moisture that came in with the machine and the packaging. That moisture condenses on cold steel as the container moves between climates and drips onto the equipment — the condition known as container rain.
What actually helps is removing the water source: a panel that is dry before the box is closed, desiccant sized to the internal volume, and a vapour barrier on the right side of the assembly. What the construction contributes is a covered panel edge, because a steel-wrapped rim exposes less raw material to take up moisture first.
Requirement six: the box can be opened and closed again
Machines are inspected. Sometimes at the destination port, sometimes by the customer before acceptance. A box that was closed with a nail line is opened destructively and cannot be re-closed properly, so the machine spends the rest of its life in a box that is no longer a box.
A buckle-fastened joint is opened and re-closed along the same line, with the same method. That is worth specifying even when the box is single-trip, because the opening usually happens before the trip is over.
What to put on the drawing
A drawing carrying those six items can be quoted and built without further discussion. A drawing that says "wooden box for machine" cannot, and the ambiguity is usually resolved after the order rather than before it.
| Load path | Machine mass, footprint through which it reaches the floor, and bearer positions under the frame |
|---|---|
| Lifting | Marked lifting points, and whether the box will be slung, forked or craned |
| Joint | Buckle pattern and pitch, or the alternative fixing, plus panel thickness from 5 mm to 12 mm |
| Edge | Steel edge formed and pressed, and the strip gauge it is rolled from |
| Blocking | Where the braces land, and on what structure |
| Opening | Whether the box must be re-closable for inspection |
The failures, and what they tell you
A crushed base means the load path went into the panel instead of into bearers.
An opened corner means the lift load found a fixing rather than a steel section.
A box that will not close at the destination means it racked, and racking is a squareness and lifting problem.
Wet equipment inside a dry box means condensation, and the answer is a water source and a barrier, not a thicker panel.
Four failures, four different causes, and none of them is solved by going up a panel thickness. That is the useful summary of this page: protective wood packaging for machinery is specified by load path and handling, and material is the last variable rather than the first.