Most structural steel we export leaves Shenzhen or Guangzhou in 40-foot high-cube (40HQ) containers. Containers are cheap, frequent and go door to door. But a 40HQ has hard limits on length, height and payload, and steel that ignores them ends up on expensive special equipment or a break-bulk vessel.
This guide gives the numbers we use when we detail and pack steel: container dimensions, special equipment, break-bulk thresholds, bundling and lashing practice, how we build a loading plan and typical tonnage per container for each member type.
- 40HQ dimensions and payload
- Open-top and flat-rack
- Container vs break-bulk
- Packing, bundling and lashing
- Loading plan and tonnage per container
- FAQ
Written by the Guiguan Steel Engineering Team. Published October 2026. Figures are typical values and are confirmed per project in our quotation.
40HQ container dimensions and payload
| Container | Internal L × W × H (m) | Door W × H (m) | Max payload | Practical max member |
|---|---|---|---|---|
| 40HQ high cube | 12.03 × 2.35 × 2.69 | 2.34 × 2.58 | about 26 t | 11.8 m long, 2.2 m wide, 2.5 m high |
| 40GP standard | 12.03 × 2.35 × 2.39 | 2.34 × 2.28 | about 26 t | 11.8 m long, 2.2 m high |
| 20GP standard | 5.90 × 2.35 × 2.39 | 2.34 × 2.28 | about 28 t | 5.7 m long; dense short items |
Typical ISO container values. Payload varies by owner and by road weight limits at destination.
The 11.8 m practical length leaves room to slide members through the doors and fit timber and lashing. We detail splices so that every primary member is 11.8 m or shorter unless break-bulk is agreed. Usable payload is often lower than 26 t because many countries limit gross truck weight. Check local axle limits before loading heavy steel for inland delivery.
Open-top and flat-rack containers
When members are too tall, too wide or too heavy for a closed box, the next step is special container equipment.
| Equipment | When to use | Limits | Indicative cost vs 40HQ |
|---|---|---|---|
| 40ft open top (40OT) | Tall items, crane loading from above: trusses, built-up frames | Length 12.0 m; height can exceed with tarpaulin (out-of-gauge) | 1.3–1.8× |
| 40ft flat rack (40FR) | Wide, long or heavy items: box columns, girders, truss segments | About 39–40 t payload; over-width and over-height allowed | 1.8–3× |
| Two flat racks combined | Members 12–24 m long | Needs carrier approval and special stowage | 3× and up |
Indicative multipliers on 40HQ freight. Out-of-gauge cargo is stowed on deck or top tier and confirmed per booking.
Open tops and flat racks have limited availability on some routes. We book them early and confirm space before we finalise splice locations.
Break-bulk vs container shipping for steel
Break-bulk means loading members directly into the vessel hold or on deck, without containers. It pays when the steel is long, heavy or the volume is large enough to charter space.
| Factor | Container (40HQ / OT / FR) | Break-bulk |
|---|---|---|
| Member length | Up to 11.8 m (HQ) or about 12 m (FR) | Up to our 24 m / 60 t single-piece limit and beyond |
| Shipment size | Any size; best below about 1,500 t | Usually economic above 1,500–3,000 t, or with many oversize pieces |
| Ports | Any container port; door delivery | Needs break-bulk berth and heavy-lift cranes at destination |
| Handling damage | Low; steel protected in the box | Higher; needs more dunnage and coating touch-up |
| Sailing frequency | Weekly or more | Monthly or by charter |
| Splices on site | More bolted splices | Fewer splices, faster erection |
A rough threshold: if more than about 30% of the tonnage is longer than 12 m or heavier than 20 t per piece, price break-bulk alongside containers. For truss projects such as the Shenshan grain reserve trestle, the fewer site splices can save more than the freight difference. See steel trusses and space frames for segment sizes.
Packing, bundling and lashing
Good packing protects the coating and makes unloading on site fast. Our standard practice:
- Bundle by piece mark and erection zone. Purlins and girts nest in bundles of 1.5–2.5 t, strapped with steel bands at 2 m centres.
- Timber dunnage between layers. Hardwood or fumigated softwood (ISPM 15) at 2–3 m centres keeps members off the floor and allows forklift access.
- Protect the coating. Rubber or felt pads under straps and at contact points; galvanized members separated to avoid wet-storage stain.
- Loose parts in crates. Bolts, nuts, washers and small cleats packed in labelled wooden boxes or steel crates, 0.5–1 t each.
- Tag every bundle. Piece marks, weights, project and container number on weatherproof tags that match the packing list.
- Floor load spread. Heavy pieces sit on dunnage that spreads the load across the cross-members, not on point contacts.
Lashing and securing
Members are lashed to the container lashing points with polyester straps or steel wire, rated for at least twice the cargo weight they restrain. Gaps are blocked with timber so cargo cannot shift longitudinally. We keep the centre of gravity near the middle of the container: no more than 60% of the weight in either half of the length. Heavy columns are placed on the floor first, lighter frames and bundles on top. Every container gets SOLAS verified gross mass (VGM) before it is gated in.
Loading plan and tonnage per container
We generate the loading plan from the same Tekla model as the shop drawings, so piece marks, weights and dimensions are exact.
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Group by erection sequence
Members for the first erection zone ship in the first containers, so the site can start before the last container arrives.
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Fill by weight and volume
Dense items are mixed with bulky frames so each container lands near 20–24 t without exceeding 26 t.
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Issue packing list per container
Piece marks, quantity, weight and bundle number per container, matched to the BOM.
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Photograph and seal
Photos at each layer, final lashing and seal, sent with container and seal numbers.
Example tonnage per 40HQ
| Cargo | Typical t per 40HQ | Limited by |
|---|---|---|
| Tapered welded H frames (PEB) | 18–23 | Volume |
| Purlins and girts, nested bundles | 20–25 | Weight / volume |
| Rolled H beams, straight | 23–26 | Weight |
| Box columns, heavy plate | 24–26 | Weight |
| Pipe truss segments | 8–14 | Volume |
| Truss floor deck panels | 20–24 | Weight |
| Sandwich panels, 50–75 mm | 8–12 | Volume |
| Bolts, anchors and cleats (20GP) | 18–25 | Weight |
Typical values from our packing lists. Actual figures depend on member shapes and destination weight limits.
A 10,000 m² warehouse frame of about 380 t ships in about 17 × 40HQ, as shown in our cost per ton guide. Transit from Shenzhen: Manila about 3 days, Malaysia about 4, Indonesia about 6, Australia 12–15. Shipping documents and inspection records are covered on quality, NDT and shipping. Market-specific notes: Australia, Philippines and Saudi Arabia.
Questions engineers ask about this topic
Need a project-specific answer? Our engineers reply within 24 hours.
How many tonnes of steel fit in a 40HQ?
The payload limit is about 26 t. PEB frames usually fill a 40HQ by volume at 18–23 t. Dense items such as box columns or rolled beams reach 24–26 t.
What is the longest steel member that fits in a 40HQ?
We detail to 11.8 m. The internal length is 12.03 m, but members need clearance to pass through the doors and for dunnage and lashing.
When should I choose break-bulk instead of containers?
Consider it when the shipment is above about 1,500–3,000 t, or when many members are longer than 12 m or heavier than 20 t per piece, and the destination port has break-bulk berths and heavy-lift cranes.
Do you supply loading plans and photos?
Yes. Each container has a packing list matched to the BOM, layer-by-layer photos and the container and seal numbers, sent before the vessel sails.
