An export crate is a purpose-built wooden case that protects heavy, valuable or fragile goods through sea, road, rail and air transport. Most are built on a skid base so forklifts and cranes can lift them, from solid timber or plywood, and must meet ISPM 15 if solid wood is used. In Germany, the HPE packaging guidelines are the common technical reference for how such crates are designed.
What an export crate is for
Machines, equipment, spare parts and instruments are often too heavy, awkward or valuable for cartons or standard pallets. An export crate gives them a rigid outer shell, a base for lifting and a frame to which the cargo is secured. Over a long journey the shipment faces repeated crane lifts, stacking pressure, vibration, humidity and rough handling, so the crate has to be designed for the whole route rather than a single leg.
The crate is only one part of the protection system. Corrosion protection, moisture barriers and internal blocking work together with the wood structure; see seaworthy packaging for machinery and heavy goods.
Main crate types
Export crates differ mainly in how much of the cargo they enclose and how the walls are built.
| Type | Construction | Typical use |
|---|---|---|
| Open crate | Base with uprights and battens, no sheathing | Robust goods that tolerate weather, or goods wrapped in barrier film |
| Sheathed (closed) crate | Frame covered with boards or plywood on all sides | Goods that need protection from impact, dust and handling |
| Frame crate | Skeleton of beams, braces and diagonals around the cargo | Large or long items where weight is saved |
| Skid-based crate or case | Base of two or more runners with a floor and cargo fixed to it | Heavy machinery lifted by forklift or crane |
| Plywood case | Panels of plywood on a timber frame | Lighter goods and when plywood reduces weight and ISPM 15 exposure |
The HPE guidelines for packing technical goods, in their 2010 second edition, describe two main groups: cases of types A1 to A6 for goods up to 500 kg, ranging from simple cases without battens to reinforced designs with diagonal bracing, and types B1 to B3 for heavier goods, built on runners so they can be lifted by fork truck.
Base and skid design
The base carries the load and defines how the crate is handled. According to the HPE guidelines, cases on runners should have:
- at least two longitudinal runners, with no more than 100 cm (39 in) between them,
- fork-entry openings at least 10 cm (3.9 in) high,
- load distributed across the runners rather than concentrated at points, and
- additional attachment points where crane or cable lifting is expected.
The center of gravity should be marked clearly on the outside, and lifting points must be designed for the actual weight. Heavier crates need stronger runners, closer cross members and, for very heavy loads, steel reinforcement or lifting lugs. For pallet-based alternatives see skids vs pallets.
Timber and construction details
The HPE guideline specifies sawn timber of grade S7 or MS7 (semi-dry) for boards, and S10 or MS10 for battens and joists. It gives a tolerance of ±2 mm for boards under DIN 4071, batten width of at least 8 to 10 cm with spacing around 80 cm, and edge boards at least 10 cm wide. These are minimum recommendations for typical industrial crates; designers should always check calculations for the specific load.
General practice includes:
- Use dry timber to limit shrinkage and mould during transport; see wood moisture content and mould and blue stain.
- Fasten with ring-shank nails or screws sized for the load.
- Use diagonal braces on walls to resist racking.
- Fix the cargo to the base with bolts, straps or blocking, not only through friction.
- Leave space for forklift access and for the cargo's own lifting points.
ISPM 15 and marking
Solid wood used in crates for international shipments must meet ISPM 15. The HPE guideline notes that treatment applies to solid timber of 6 mm or more in thickness, and that heat treatment requires 56 °C core temperature for 30 minutes. Treated wood has to carry the IPPC mark with country code, producer number and treatment code; see the ISPM 15 mark guide and heat treatment.
Plywood and other processed wood panels made with glue, heat and pressure fall outside the scope of the standard, which is one reason plywood sheathing is popular for crates; frames and skids made from solid wood still need treatment. See ISPM 15 exemptions.
Handling symbols such as "This way up", "Fragile", "Keep dry" and sling points should follow the symbols standardized in ISO 780, which the HPE guidelines also reference. See also packaging markings and symbols.
Moisture and corrosion protection
Metal goods suffer corrosion if humidity gets into the crate, especially at sea where temperature swings cause condensation. The HPE guidelines describe three protection methods: desiccant bags in a sealed barrier film, protective coatings applied to clean dry goods, and volatile corrosion inhibitor (VCI) methods. For desiccant protection, they specify keeping relative humidity at or below 40% inside sealed polyethylene film, with a minimum film thickness of 0.2 mm, for periods of up to 12 months.
Choosing and specifying a crate
A specification should include:
- gross weight, dimensions and center of gravity of the cargo,
- route and transport modes, including container or breakbulk shipping,
- stacking requirements, whether the crate can be stacked or not,
- lifting method: forklift, crane, sling or all of these,
- climate and storage conditions at origin and destination, and
- required markings and documents, including ISPM 15.
Details on equipment-focused crates are covered in wooden packaging for machinery, and the German guideline itself in the HPE packaging guidelines.
Frequently asked questions
Do export crates need ISPM 15 treatment?
Yes, if they contain solid wood and are shipped internationally. Heat treatment and the IPPC mark are standard; panels such as plywood are exempt, but solid-wood runners and frames are not.
What are the HPE guidelines?
They are packing guidelines published by the German federation HPE for export packaging of technical goods. The 2010 edition defines crate types, base design, timber requirements, ISPM 15 compliance and corrosion protection methods.
How high must fork openings be?
The HPE guideline gives a minimum of 10 cm (3.9 in) for fork entry on cases on runners, though the handling equipment actually used may need more.
Is plywood or solid timber better for crates?
Plywood saves weight and avoids ISPM 15 treatment for the panels; solid timber is stronger for frames and runners. Many crates combine both.
Sources
- HPE 2010 guideline for packing — HPE Bundesverband Holzpackmittel, Paletten, Exportverpackung
- ISPM 15 (2018): Regulation of wood packaging material in international trade — International Plant Protection Convention
- GDV packaging handbook — German Insurance Association (GDV)
- IMO/ILO/UNECE Code of Practice for Packing of Cargo Transport Units (CTU Code) — International Maritime Organization