ISO Shipping Containers or refrigerated containers are containers that are used for intermodal freight transport, which require refrigeration of temperature controlled cargo. They have integrated refrigeration units that runs from external electric power supplies from land based sites, container ships or from quays.
They are used in intermodal freight transport, and are key items used in a system known as containerization or containerisation. They are also known as intermodal transport units are loaded and sealed intact onto railroad cars, ships, planes and trucks etc. The introduction of them resulted in huge improvements in port handling efficiency, which had the effect of lowering freight charges, and lowering general costs which helps boost the flow of trade.
Another type of refrigeration uses CO2 for cooling. ISO containers using CO2 cooling systems are able to keep the cargo frozen solid for up to 30 days. There are many types of ISO containers available for different purposes. Ones that use refrigeration are commonly referred to as reefers or just refrigerated containers. The impact of containers on society is huge, and consumers all over the world enjoy the benefits of fresh produce as a result of them.
When transportation is over land/road the ISO shipping containers will be powered from diesel powered generators, which are hooked up to the container while they are travelling. Some ISO shipping containers are water cooled, and these systems are used when the container is stored in a vessel without adequate ventilation.
Many manufactured products humans consume, will have spent some time in shipping containers. The introduction of shipping containers led to purpose built vessels, which started in Denmark in 1951. Shipping containers have revolutionized cargo shipping, and today around 90% of non bulk cargo world wide is transported by shipping containers stacked on ships.
Containers are intended to be used constantly. This means being loaded with fresh cargo for a new destination soon after having emptied its previous cargo. Sometimes this is not possible and in some cases the cost of transporting an empty container to a place where it can be used is considered higher than the worth of the used container. Many shipping lines and container leasing companies have become very adept at repositioning empty containers from areas of low or no demand. However damaged or retired containers may also be recycled in the form of shipping container architecture, or the steel content salvaged.