A container user should be aware of the most important structural differences between containers. Users are responsible for making the appropriate preparations for packing and securing cargo. Exterior markings provide container loading capacity.
We will describe the fundamental components and design of standard box containers.
Basic Container FrameThe load-carrying element of all box containers is a steel framework, consisting of four corner posts and two bottom side rails, two top side rails, two bottom cross members, a front top end rail and a door header.
Bottom Cross MembersBottom cross members serve as supports for the container floor. Additional bottom cross members are fitted between the bottom side rails, to serve as supports for the floor covering.
Side and End WallsThe side and end walls are the components of a standard box container which are capable of bearing the least load. Most walls are constructed of 12-16 gauge steel.
Roof PanelRoof panels are normally constructed of the same materials used for the walls and are designed to prevent water from pooling on the top of the container. When containers are stacked, the load is placed on the corner posts and a reinforced panel located at each corner, not on the roof panel. While the roof panel will normally support several hundred pounds, WALKING ON THE ROOF PANEL IS NOT RECCOMMENDED. Load bearing capacity varies by container construction, age and condition.
Essential Container ComponentsThe following figure illustrates the essential components of standard box containers. Additional components include the door bar handles and the locking components required for sealing.
Standardization of container components and dimensions allows for the use of standard handling equipment and transportation. The majority of containers used for maritime transport are constructed according to ISO standards. ISO corner castings are a key component.