The Importance Of Corner Posts, Connectors, And Other Structural Equipment

When it comes to shipping containers, that singular, rectangular, rigid structure is actually made up of numerous structural components. Each component must work well with the other so that together, they cannot only transfer what is contained within, but keep it safe. Many of the parts listed below are common in not only shipping containers but vans and trailer bodies as well.

Various Parts of a Shipping Container

The basic structural components of a shipping container are as follows:

  • corner posts
  • bottom rails/top rails
  • cross members
  • floor
  • sidewalls
  • roof

Whether a container is empty or loaded, whether it is in the back of a truck or out at sea, racking forces and weight are transferred successfully when these components all work together. Let’s take a brief look at each of the components individually.

The All-Important Corner Posts

Door end and front-end corner posts are comprised of high tensile steel. Any repairs that are executed to corner posts must conform to a very specific criteria. The collapse of a stack could be the result of corner posts that failed due to unsafe repairs.

How to spot problems:

  • On post insert welds, look for any hairline cracks or splits.
  • Inserts – on the front-end posts, check for full profile inserts; any terminating within 300 mm from a corner; any being fewer than 300 mm long.

Bottom and Top Rails

A container’s actual frame is formed by the rails. Box section profiles or 10 mm flat bar profiles make up the top rails. When the container is being loaded onto a trailer, helping to decrease the possibility of rail piercings from twist lock points are the front end and door end bottom rail cutouts.

Things to watch for:

  • By no more than 40 mm should panels or rails ever bow outside the container envelope (they really shouldn’t bow at all).
  • Neither bottom nor top rails, where the rail meets casting (around corner castings at weld points), should have any cracks.

Cross Members and Floor

Laminated marine plywood is used for the floor.

Things to watch for:

  • Fitted plywood pieces that are too short (they do not cover at least three cross members).

Visible from beneath the container and along with forklift pockets, flooring is also made up of structural components referred to as cross members.

Things to watch out for:

  • As above, cross members that are too short.
  • Beneath a corner casting’s bottom face, weaknesses can occur.
  • General wear and tear, or the use of inferior materials, can result in flooring displaying hairline fractures.

Side Wall Panels

For rigidity and strength, and created with corrugated profiles, side wall panels are constructed of steel sheets.

Things to watch for:

  • Particularly in units that are older, on the bottom lower half of a panel, rust can develop.
  • Rust may also show up at weld seams (roof seams are usually highly visible).
  • Bowing and impact damages.


Again, for rigidity and strength, and constructed with corrugated profiles, the roof is made of steel sheets.

Things to watch for:

  • Particularly on older units, bubble rust, pitting, and weaknesses.
  • Around a corroded area, tiny pinholes may form.

The CSC Plates, Fittings, and Doors

The container safety convention (or CSC plates) is located on the left-hand door and on every container. On this plate you will find a CEP information, technical data, and data by the owner.

Things to watch for:

  • Door hinge pins should never be missing and must be intact at each hinge.
  • Doors must open to 180°.
  • Gaskets on doors should not be loose or hanging.
  • To assure proper sealing and that there are no holes, there should be no daylight showing when both doors are closed.

Mickey Genuine Parts carries corner post connectors, side/front connectors, posts, van posts, and more. We also have service centers located throughout the United States, should you need help with repairs or replacements of van or trailer parts. Our inventory is impressive, but varies, so always check to be sure that the part you need is in stock before ordering. If your part is not in stock, we can get it for you and expedite shipping. Contact us today with any questions, orders, or comments.

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