Cargo Containers
Cargo containers can serve numerous functions for a business. Standard, unmodified containers cross the globe daily, transporting cargo of every sort. Refrigerated containers are used to move and store perishable goods. Modified containers are even used as on-site storage and even mobile office space. These units are available on a rental basis or for sale by custom manufacturers.Standardization
As industry and globalization increased the flow of goods over land and sea, the shipping industry standardized the size and shape of cargo containers for maximum storage capacity and compatibility. The “standard” container measures 8 feet wide by 8.5 feet high. Increasingly, the “high cube” container, or “hicube” for short, is becoming popular as it offers an increased height of 9.5 feet.
“Half-height” containers are 4.25 feet high and are designed for carrying steel rods and other heavy loads that don't require a great deal of space. Standard lengths are 20 feet and 40 feet, though 10 foot and 30 foot containers are also available.
It is important to remember that these measurements are standard external dimensions. The internal size can vary depending on the thickness of the steel used. There are usually 8 inches high forklift
pockets underneath the container, making the interior height of a standard container 7 feet 10 inches. The standard interior width is 7 feet 8 .635 inches. Subtract 7 inches from the exterior length to find the interior size.
Rating, Tare, and Payload
While the size of the cargo to be loaded into a container is a major concern, it is also important to keep in mind the weight of the cargo. Each cargo container has a specified “rating” or maximum weight
permissible for a particular container and its contents. This rating is used primarily when the container will be moved by ship, truck, or train. The standard rating for a 20-foot long container is 24,000 kilograms (52,900 lbs.). The rating for a 40-foot container is 30,480 kilograms (67,200 lbs.).
The “tare mass” or “tare” of a container is its empty mass (or weight). This weight varies depending on the materials used. A 20-foot cargo container may weigh anywhere from 1,800 kilograms to 2,400
kilograms. A 40-foot container may weigh 2,800 kilograms to 4,000 kilograms. Containers with added equipment, such as refrigeration units, may have a higher tare than these, so it is best to confirm the tare for each container individually.
The permissible payload weight is found by subtracting the Rating from the Tare. With this number, a company can very accurately gauge how many cargo containers they will need.
Non-standard usage
In addition to simple storage and shipping, cargo containers are often used as mobile field offices. These units can be outfitted with windows, wall paneling and insulation, flooring, electric and phone outlets, lighting and air conditioning. These offices are ideal for on-site management for long or short-term projects.