Standard containers  
Standard containers are also known as general purpose containers. They are closed containers, i.e. they are closed on all sides. A distinction may be drawn between the following types of standard container:  
Standard containers with doors at one or both end(s)  
Standard containers with doors at one or both end(s) and doors over the entire length of one or both sides  
Standard containers with doors at one or both end(s) and doors on one or both sides  
In addition, the various types of standard container also differ in dimensions and weight, resulting in a wide range of standard containers. Standard containers are mainly used as 20' and 40' containers.
Containers with smaller dimensions are very seldom used. Indeed, the trend is towards even longer dimensions, e.g. 45'. The principal components of a standard container are shown in following diagram of a 20' plywood container: Frame and bottom cross members are made of steel profiles, while three different materials are used for the walls:  
1. Steel sheet, corrugated  
Characteristics:
low material costs 
easy to repair 
high tare weight 
susceptible to corrosion 
difficult to clean owing to corrugated walls 
2. Aluminum sheet in conjunction with stiffening profiles
Characteristics:
low tare weight
high material costs
easily deformed, very quickly dented
3. Plywood with glass fiber-reinforced plastic coating (plywood + GRP)
Characteristics:
easy to clean owing to smooth surfaces
easy to repair 
strong and resilient, does not dent
moderate material costs
moderate tare weight

The cost advantages have led to the predominant use of steel for container walls.
The floor is generally made of wood, usually planking or plywood. Although wood is relatively expensive, it has substantial advantages over other materials: it is strong and resilient, does not dent, may be easily replaced during repairs and, when appropriately finished, has an adequate coefficient of friction, which is important for cargo securing.  
Standard containers may additionally be equipped with certain optional extras:

Forklift pockets: these allow handling of empty containers with forklift trucks. Packed containers must not be picked up in this way unless specifically permitted. Forklift pockets are installed only in 20' containers and are arranged parallel to the center of the container in the bottom side rails. 40' containers do not have forklift pockets, since the pockets are relatively close together and such large containers would be difficult to balance. In addition, the forklift truck travel paths are often not wide enough.  
Gooseneck tunnel: Many 40' containers have a recess in the floor at the front end which serves to center the containers on so-called gooseneck chassis. These recesses allow the containers to lie lower and therefore to be of taller construction. 
Grappler pockets: In general, containers are handled by top spreaders using the corner fittings or corner castings. However, some containers have grappler pockets for handling by means of grapplers.  
 
Special fittings are available for transporting special cargoes: 
Clothes rails for hanging garments: Special lashing rings attached to the top side rail serve to accommodate clothes rails on which textiles may be transported hanging on clothes-hangers. These are often used in the East Asia import trade. Additional lashing rings are installed on the bottom side rail and the corner posts.  
Inlet (bulk bag or liquid bulk bag): Plastic liners may be suspended in standard containers for transporting bulk cargo or non hazardous liquids.  
The wooden components of most containers are impregnated against insect infestation, since, when lumber is used, it may, under certain circumstances, be necessary to comply with the quarantine regulations of the country of destination and a phytosanitary certificate may have to be enclosed with the shipping documents. Information may be obtained from the phytosanitary authorities of the countries concerned.  
Dimensions/weights
The following are some of the most important details relating to certain types of standard container . 
Standard container of steel: 20' long and 8'6" high with corrugated walls and wooden floor
Internal dimensions Door openings Weights Volume

[m砞
Length

[mm]		 Width

[mm]		 Height

[mm]		 Width

[mm]		 Height

[mm]		 Max. gross wt.

[kg]		 Tare weight

[kg]		 Max. payload

[kg]
5895 2350 2392 2340 2292 30480 2250 28230 33.2
5895 2350 2385 2338 2292 24000 2250 21750 33.2
5879 2330 2370 2330 2290 24000 2250 21750 33.0
5889 2346 2372 2330 2272 24000 2360 21640 32.8
5885 2350 2403 2338 2292 24000 2150 21850 33.15
5884 2335 2390 2335 2292 24000 2200 21800 33.1
5899 2350 2394 2338 2280 24000 2180 21820 33.2
5891 2330 2376 2330 2272 24000 2300 21700 33.0
5880 2330 2380 2330 2275 24000 2300 21700 33.0

Standard container of steel: 40' long and 8'6" high with corrugated walls and wooden floor
Internal dimensions Door openings Weights Volume

[m砞
Length

[mm]		 Width

[mm]		 Height

[mm]		 Width

[mm]		 Height

[mm]		 Max. gross wt.

[kg]		 Tare weight

[kg]		 Max. payload

[kg]
12029 2350 2392 2340 2292 30480 3780 26700 67.7
12024 2350 2387 2340 2292 30480 3810 26670 67.7
12033 2350 2394 2338 2280 30480 3800 26680 67.7