Dropbox Answers the Question: What is a Shipping Container?

Posted on Wed, Jun 23, 2010 @ 11:06 AM

Shipping Containers, ISO Shipping Containers, Milvan Cargo Container

What is a Shipping Container?  At Dropboxinc.com, we get a high volume of traffic and a number of people asking this very question. More often than not our answer is "a solid steel box" or a "heavy duty connex container". In lay terms a shipping container is a steel box consisting of roofs and walls, floors, paint and corner castings.

Roofs and Walls:

Typically roofs and walls of ISO Shipping Containers are constructed by two kinds of materials. Most commonly containers use 16 gauge corrugated steel as the primary component for construction. Corrugated steel is often used because it is cost effective and is easy to repair. From time to time Dropbox Inc will also come across aluminum sheet shipping containers. As and alternative to corrugated steel, aluminum has a lower tare weight but can be easily dented or scratched and is harder to repair.

Shipping Container, Connex Shipping Container, Milvan Cargo Container


The floor of shipping containers is primarily made of wood planks or plywood with steel support beams. The standard thickness for international shipping containers flooring is 1 1/8" thick. Even though wood is relatively expensive, it has significant advantages over other materials; it is strong and resilient, does not dent, and may be easily replaced during repairs. Along with the wood, below the floor are steel cross members or beams that increase the strength so that you can put up to 28,000 kg in a single 20' container.


Due to the long-term exposure to the marine elements, containers are manufactured with highly durable, long-lasting paint. The exterior and interior of the bare steel container surface is primed with a zinc rich primer and dried. Once the primer has finished drying a final top coat of marine paint is then applied. The marine paint used to paint shipping containers typically contains zinc phosphate and is based on acrylic resin and non-chlorinated plasticizers.

Corner Castings:

Corner castings are the steel corner supports of a connex container which bears all of the weight when containers are stacked. ISO standards state that the corner posts of an ISO shipping container or milvan should be tested to a load of 86,400 kg. The load barring properties of these units makes them stackable up to 8 high.

For more information on shipping containers and custom container modifications contact Dropboxinc.com and check back as our blog is regularly updated.

Tags: shipping container modification, milvan modification, conex container modification, custom shipping container modification, custom container modification, shipping container office, portable construction site office, modular construction site office