Freight Containers:
rating, tare mass and payload of containers
Rating
Rating is the maximum gross mass (or weight), that is, the maximum permissible weight of a container plus its contents. The rating of a 20' dry cargo container is 24,000 kgs. (52,900 lbs.), and a 40', including the high cube container, is 30,480 kgs. (67,200 lbs.).
Tare Mass
Tare Mass - tare weight or tare - is the mass (or weight) of empty container, including all fittings and appliances used in a particular type of container in its normal operating condition.
The tare mass of containers may vary due to the different construction techniques and materials used in the container. A 20' x 8.5' dry cargo container may weigh 1,800 kgs. to 2,400 kgs., a 40' x 8.5' may weigh 2,800 kgs. to 4,000 kgs, and a 40' x 9.5' may weigh 3,900 kgs. to 4,200 kgs. Some dry cargo containers may fall outside the indicated weight range. The reefer weighs more than a dry cargo container of the same size.
Payload
Payload is the maximum permitted mass (or weight) of payload, including the dunnage and cargo securement arrangements that are not associated with the container in its normal operating condition. Therefore, Payload = Rating - Tare Mass.
If the tare mass of a 20' dry cargo container is 2,400 kgs. and a 40' is 3,900 kgs., the payload of 20' is 21,600 kgs. (i.e., 24,000 kgs. minus 2,400 kgs.) and 40' is 26,580 kgs. (i.e., 30,480 kgs. minus 3,900 kgs.). However, the exporter may be prohibited to have that much payload in areas where there are legal limitations to the overall load of a vehicle.
In exporting, it is common to encounter a payload of 17,500 kgs. or less in the 20' container, and 24,000 kgs. or less in the 40' container.
