Most cargo moves in one of two boxes, and most of the remaining problems come from cargo that should not have. Knowing which container suits your load — before you book — prevents the majority of avoidable equipment costs.
The 20ft general purpose container is the workhorse for dense cargo. It offers roughly 33 cubic metres and, depending on the operator and the road limits at destination, a payload commonly in the region of 21 to 28 tonnes. Because it hits weight before volume on most cargo, it suits stone, machinery, metal goods and anything with a high density.
The 40ft general purpose doubles the volume to around 67 cubic metres but does not double the payload. This is the single most misunderstood point in container selection: two 20ft containers carry substantially more weight than one 40ft, while one 40ft carries far more volume than one 20ft. If your cargo is heavy, two twenties is often the correct and cheaper answer.
The 40ft high cube adds roughly a foot of internal height, taking usable volume to around 76 cubic metres for the same payload. For light, bulky cargo — furniture, textiles, packaging, most consumer goods — it is almost always the right default, and the rate premium over a standard 40ft is usually small relative to the extra volume.
Open top containers have a removable tarpaulin roof and exist for cargo that must be loaded by crane from above, or that exceeds the door height but fits within the container footprint. Cargo may protrude above the roof line, in which case it becomes out-of-gauge and is priced accordingly.
Flat racks have no sides or roof and exist for cargo that exceeds the container width or cannot be enclosed. They are the standard answer for machinery, vehicles, structural steel and project pieces. Because out-of-gauge cargo blocks adjacent slots on the vessel, pricing reflects the space consumed rather than the space occupied — which is why accurate dimensions matter enormously.
Reefer containers are refrigerated units with their own power requirement, used for temperature-controlled cargo. They need a defined set-point, monitoring, and power continuity through the whole chain including the terminal and the road legs. A gap in the cold chain at any point can spoil the load, so the routing has to be planned around power availability, not just transit time.
Two practical rules cover most decisions. First, calculate both the volume and the weight before choosing, because whichever limit you hit first determines the equipment. Second, if the cargo is anywhere near a dimensional limit, measure it properly and declare it accurately — the cost of being found out-of-gauge at the terminal is far higher than the cost of booking the right equipment in the first place.
