What Makes a Shipping Container Seaworthy?

This guide is intended to provide a little background about what makes a shipping container seaworthy, how is it checked or graded and what sorts of repair standards are involved.

In very basic terms, shipping containers are big metal cans designed to keep cargo dry, secure and safe for transit while having the capacity to be transferred easily from boat to train to truck as necessary. They are built and regulated by a set of international standards which determine the sizes and tolerances of the containers, and therefore how seaworthy there are. This also ensures that containers from one factory will work fine alongside those built in an entirely different factory.

A marking process is used to indicate that a container has been checked and is seaworthy.

Design and Structure

Shipping containers are designed and built to meet the international standards set out in the Container Safety Convention or International Convention for Safe Containers (CSC) drawn up by the International Maritime Organisation (IMO) and the European Economic Community (EEC). These standards ensure the design and structure of a shipping container is thoroughly tested before use.

Each new container design or modification has to have a prototype built that undergoes some serious (and expensive) testing. These tests are always reviewed by one of a few internationally recognised classification societies who ensure the methods are accurate and standardised.

Maintenance and Repair

It is the standard of repair that is the most important factor in what makes a shipping container seaworthy and this is the responsibility of the container’s owner.

The vast majority of shipping containers are owned by shipping lines (the companies that own the boats) or major international leasing companies, who in turn lease their containers to the major shipping lines. These 2 groups own the majority of the 10-15 million containers in circulation.

There are two maintenance programmes in use to keep shipping containers repaired and to show others they have been properly looked after and are seaworthy: The Periodic Examination Scheme (PES) and the Approved Continuous Examination Programme (ACEP).

Shipping Container CSC plate exampleA container in the periodic examination scheme will usually have a little white sticker on the Container Safety Convention (CSC) plate with an expiry date (see image left). When the container is new this expiry date may be stamped into the metal CSC plate itself rather than showing on a sticker. The examiner will only add a new expiry date if he or she is happy with it, so while some containers may be given a periodic check and get 3 years CSC validity, some may only get 3 months. While the typical minimum CSC plate validity is 3 months, our standard used containers are usually supplied with a 6-12 month CSC plate. 5 years is the maximum CSC validity offered ex-factory. However, the date on a CSC plate is not necessarily an indicator of quality. Much like a car’s MOT, a car with 1 month until its next MOT isn’t necessarily in poorer condition than a car with 6 months left. It all depends on what’s happened to it since it was last looked at.

A container in the continuous examination programme will be marked with the fleet owner’s unique ACEP number, although often (but not exclusively) in the same place as the CSC expiry sticker. Each time the container goes into one of their depots they will have it checked and will be motivated to carry out any repairs required (this largely how the depots make their money).

Again, it is important to note that in the same way an MOT for your car only indicates it was good on the date tested, the same applies for a CSC exam. There is nothing stopping a customer / packer / random stranger driving a fork lift truck through the side of a shipping container after its CSC exam (and the same goes for any other kind of damage) and after the CSC expiry sticker has been added. As such, any port, shipping line or container facility will always reserve the right to refuse any container they choose on safety grounds or if they believe it is not seaworthy at the point they receive it. The same applies for pretty much any company in the transportation chain if they are not happy with the container or the safety of the job, so it’s simply not worth the risk and anyone will reserve the right to refuse your container if they aren’t happy with it.

In both cases it is the container fleet owner who remains responsible for the level of repairs undertaken. This may seem like a less than ‘watertight’ system (no pun intended) however, much like the MOT system for cars on the UK roads it does mean that problems with shipping containers that aren’t structurally sound are extremely rare within the industry.

Shipping Container Repair Standards

Aside from the shipping container maintenance procedures outlined above, there are also two main types of repair standards that can be applied to most shipping containers.

Many shipping lines repair their own shipping containers to the Unified Container Inspection and Repair Criteria (UCIRC) as drawn up by the International Chamber of Shipping (ICS).

Other container leasing companies and their customers operate to a similar set of standards drawn up by the International Institute of Container Lessors (IICL), where they can chose to meet a number of grades from 1 to 5. Generally speaking grade 5 is the lowest and cheapest grade to repair to, and any containers sourced after a leasing company has finished with them will commonly be repaired to IICL grade 5 standard only. Grades above IICL 5 are rarely used these days and are often deemed unnecessarily strict. The IICL grade 5 can very broadly be deemed similar to UCIRC standards in the fact they outline requirements for a structurally sound and safe shipping container.

Other repair standards do exist, however these two are the most commonly recognised and universally adopted repair standards in use worldwide.

It should be noted that both repair standards make little or no reference to the appearance of a shipping container. This is of no importance to a shipping container company, for whom the only consideration is the container’s capacity to transport goods safely and securely.

Can I get my shipping container checked for export?

While this is a common question it is unfortunately as difficult one to answer. If you are buying the shipping container from us you do of course have the peace of mind when we say its CSC plated, its CSC plated. In the vast majority of cases where you may have purchased this container elsewhere, it is not viable to get a container that you’ve brought some time ago checked and repaired to a seaworthy standard, but please call our office to chat through the options if this is something you are considering, and a separate guide detailing this area will be published soon.

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