Container glossary
What is a general purpose (GP) container?
A general purpose (GP) container is the ordinary enclosed steel box with doors at one end, built for dry cargo that needs no temperature control and no special access. In everyday booking language “GP” also means standard height — 2.591 m outside — as opposed to a high cube.
General purpose containers by size
| Container | External L × W × H | Internal L × W × H | Volume |
|---|---|---|---|
| 10 ft container | 2.99 × 2.44 × 2.59 m | 2.83 × 2.35 × 2.39 m | 15.9 m³ |
| 20 ft container | 6.06 × 2.44 × 2.59 m | 5.90 × 2.35 × 2.39 m | 33.2 m³ |
| 40 ft container | 12.19 × 2.44 × 2.59 m | 12.03 × 2.35 × 2.39 m | 67.7 m³ |
Data: ISO 668:2020
What makes a box general purpose
It is defined by what it lacks. No refrigeration unit, no removable roof, no missing walls, no tank: a weatherproof shell of corrugated steel on a plywood floor, loaded through a pair of doors 2.340 m wide and 2.280 m high. Cartons, pallets, drums, sacks, furniture and machinery that fit through that door all travel this way, and roughly nine of every ten boxes afloat are dry containers of this kind or their high cube sisters.
The trade has several names for the same thing: dry van (DV), dry container (DC), standard (ST or STD). None of them marks a different product. The other members of the family are set out in types of shipping containers.
GP in a booking, and G1 on the door
In a quotation or booking you will see it joined to a length: 20GP, 40GP. Written like that, GP means standard height, and the taller box is listed separately as 40HC or 40HQ. On the container itself the type is carried by the size and type code beside the number: 22G1 for a 20 ft, 42G1 for a 40 ft. How to read those four characters is explained in the ISO standards guide.
Notice that a 40 ft high cube is coded 45G1 — still G1, still general purpose by type. So the letters mean “not a special” on the door and “not a high cube” on a booking. When the height matters, confirm it by the code or the dimensions in the table above, not by the abbreviation.
Booking a 40GP when the cargo needed a high cube
The costly mistake is a planning one: stacking a load to a height taken from a high cube specification and then booking a 40GP. The standard box is 305 mm lower inside (2.393 m against 2.698 m) and holds 67.7 m³ against 76.4 m³. The top tier does not fit, and the remainder ships separately or waits. Some published tables print high cube figures under a plain “40 ft” heading, which is how the error starts; compare the two on the high cube page.
The second misunderstanding is expecting more than a dry shell. A GP container is neither insulated nor ventilated to any useful degree, so moisture inside condenses on the cold steel and drips on the cargo. Goods that mind should be packed for it — see ventilation and condensation.
Frequently asked questions
What does GP mean on a container?
General purpose: a standard enclosed dry container. In size labels such as 20GP and 40GP it also signals standard height, 2.591 m (8 ft 6 in) outside, as distinct from a 2.896 m (9 ft 6 in) high cube.
Is a dry van the same as a GP container?
Yes — dry van, dry container, standard and general purpose are four names for the same enclosed box. The ISO type code on the door, G1, is identical for all of them.
What is the difference between 40GP and 40HC?
Height: a 40HC is 2.896 m (9 ft 6 in) tall outside against 2.591 m (8 ft 6 in) for a 40GP, which gives 76.4 m³ instead of 67.7 m³. Length, width and floor area are the same.