Supply Chain

Don't Ignore Shipping Container Codes

09 March 2018

“Shipping container” and “standards” are two terms that go together like peanut butter and jelly. Or peas and carrots, rum and coke, salt and pepper…you get the idea. They go together so well that intermodal containers are often referred to as “ISO containers,” after the International Organization for Standardization codes that govern their size, markings and other aspects.

Standards and codes are important to intermodal shipping, and failing to adhere to codes can result in lost cargo and revenue, damage to cargo ships and even loss of life and limb.

Intermodal Shipping at a Glance

Intermodal shipping is so termed because its containers are compatible with multiple modes of transport. The rise in global trade during the past several decades means that goods shipped overseas almost always use multiple forms of transportation to reach their destination.

For example, imagine if a customer in New York orders a product from Japan. In an intermodal shipping process, the product is loaded into a container, which is then placed on a cargo ship. The ship crosses the Pacific and reaches the Port of Los Angeles, where a crane loads the container onto a train. The train then traverses the United States and probably arrives at a depot or distribution center, where the container is fitted onto a truck for delivery.

Intermodal shipping is a safe, secure and efficient means for product delivery in a globalized world. But changing the mode of transportation several times demands that containers be precisely standardized, so that they fit on a ship, train and truck, all in the same trip.

Size Matters

ISO 668 defines a container’s size. This standard introduced in 1968 covers each container’s external and internal dimensions, minimum door opening size and maximum gross weight. ISO designates roughly a dozen container sizes using a designation code. For example, 45-foot containers are designated with a 1 and a number of letter E's, depending on the container’s height. A 1EEE designates a 45-foot long “high” container with an external height of 9 feet 6 inches. A 1EE is a 45-foot “standard” container that’s only 8 feet 6 inches high externally. The current version of ISO 668 specifies containers ranging from 10 feet to 45 feet long.

A loaded container ship. Standard-sized containers ensure that deck space is optimized and onshore equipment is compatible. The X-shaped bracing at lower right, which keeps containers secure during transport, is called lashing. Source: Photocapy / CC BY-SA 2.0A loaded container ship. Standard-sized containers ensure that deck space is optimized and onshore equipment is compatible. The X-shaped bracing at lower right, which keeps containers secure during transport, is called lashing. Source: Photocapy / CC BY-SA 2.0

Standardizing container sizes ensures that each mode of transport is properly equipped to safely carry a container. ISO containers also allow shippers to meticulously plan for shipments. Visitors to any busy port will likely see a huge cargo ship stacked with many layers of ISO containers — knowing the precise dimensions of these containers allows ships to use every inch of their cargo space while maintaining safety standards.

Beyond the obvious problems posed by a container not standardized to specific dimensions, specifying a weight limit also helps ensure safe packaging of goods.


ISO 6346 lays out a standardized method for labeling containers. Shippers can glean a variety of information from these standard codes:

-A container number indicating its owner, category and serial number. Each number also contains a check digit for validating the owner code and serial number. Container categories specified by this code are broad: U indicates a freight container, J describes detachable container-related equipment and Z indicates a trailer or chassis.

-A size and type code representing the container’s dimensions and type — these attributes are coded, so a container’s type and size can only be discerned by those familiar with the standard. For example, the first 2 in a container labeled 22RC describes that it is 20 feet long, the second 2 indicates that it is 8 feet 6 inches tall, and the RC describes it as a reefer (refrigerated) container that does not contain food. The increase in globalization has resulted in more diverse goods transported through intermodal means, so knowing a container’s exact type and contents ensures safe handling throughout the supply chain.

Packing and Securing

The CTU Code is a non-mandatory joint publication of the International Maritime Organization (IMO), International Labour Organization (ILO) and the United Nations Commission for Europe (UNECE). It was published in 2014 and provides guidance on the packing and handling of shipping containers.

The CTU Code is comprehensive, covering topics such as chain of responsibility throughout the supply chain, packing of individual containers, load inspection, container inspection, pest management, average ocean conditions, training and more. While correct packing obviously ensures that shipped goods reach their destination safely and intact, it also helps ensure the safety of the container itself. Shipping containers are carefully arranged on a cargo ship’s deck, and although they are secured using twistlocks and lashing, improperly balanced packing can result in stresses and imbalances to a ship’s cargo. Combining these imbalances with characteristically rough seas can result in container loss.

According to 2017 data from the World Shipping Council, an average of 568 containers were lost at sea in non-catastrophic events each year from 2008 to 2016. This figure represents over 35 percent of total containers lost to all causes. While this number represents a very small fraction of the 130 million containers shipped in 2016, lost containers still have a financial and environmental impact.

A CH-47 transports a shipping container using a sling. ISO containers are not designed for sling lifting, but some suppliers weld padeyes to their corners for this purpose, increasing the risk of collapse.A CH-47 transports a shipping container using a sling. ISO containers are not designed for sling lifting, but some suppliers weld padeyes to their corners for this purpose, increasing the risk of collapse.Correct packing and securing like that described in the CTU Code has a major impact on container security. Poorly packed, overloaded or improperly secured containers are unlikely to survive a rough voyage. If they fail they may cause a domino effect on nearby containers, resulting in even more lost cargo.

Onshore vs. Offshore

ISO containers are only certified for use with onshore equipment, and using them with offshore equipment can have disastrous consequences. Offshore containers are built to completely different standards — provided by Det Norske Veritas — and are subject to dynamic lifting using slings rather than onshore cranes.

Suppliers will sometimes weld a padeye to the corners of an ISO container and sell it as an offshore container. But an ISO container’s bracing and structure is not strong enough for offshore dynamic loads, so attempting to lift it using a sling and welded padeyes may result in the entire container collapsing. Offshore containers are also designed to withstand harsh weather conditions and do not fit the standard ISO container categories, so using them interchangeably is risky at best.

The Importance of Container Standards

Failure to follow shipping container codes and standards can easily cause harm to cargo and containers, and sometimes even catastrophic disasters. The August 2015 Tianjin explosions, for example, lent a new gravity to non-mandatory codes like the CTU Code. The Tianjin disaster began as an uncontrollable warehouse fire at a container storage station but escalated to two earthquake-strength explosions after vast quantities of chemicals ignited. The blasts killed 173 people and injured nearly 800.

The Tianjin disaster was the result of many factors, including storage of vast quantities of hazardous chemicals like sodium cyanide, calcium carbide and ammonium nitrate. Local authorities failed to regulate the storage of these chemicals, and packing codes would have been unlikely to prevent such a disaster, but this type of public catastrophe helps shippers realize the importance of adhering to codes and standards, even non-mandatory ones.

While standards are important to many industries, they may be extra vital to shipping. Global shipping involves moving goods to and from areas with radically different local laws and practices. One port may follow rigorous packing and inspection policies, but if cargo makes its way to a more remote location with looser standards the container’s integrity or contents may eventually be in jeopardy.

International standards such as those administered by ISO, IMO and other organizations provide for safe and efficient shipping operations despite these differences. Following them prevents loss of goods, cargo and even human lives.

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Discussion – 2 comments

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Re: Don't Ignore Shipping Container Codes
2018-Mar-10 11:38 AM

In theory, you're totally right; no argument. The problems are in the implementation. It's not easy to standardize (who knows how many) local methods to a global standard, without external monetary/technical help.

I would like to take this opportunity to express my opinion about why the rail system is so "obsolete". Their roads are from the beginning of train-time, while the trains have evolved without improvement of the roads. Each new version of train was designed to run on the old roads, to maintain "compatibility". The fact is, the current trains have outgrown their roads. The only way to truly update the rail system is to design a totally new one from scratch, starting with a "spine" from border to border. The new system (by necessity, would not be compatible with the old, except by transfer-stations/depots). The old system could be re-used as subsidiary branches from the spine (and gradually phased out by attrition, if needed).

Container standards face a similar problem. Global standards require an upgrade/update of many local systems. And that's very difficult without outside help.

Re: Don't Ignore Shipping Container Codes
2018-Mar-10 9:31 PM

As someone who has actually been to the port ( port of Long Beach / port of Los Angeles ) and has picked up containers ( Cans ) some of the information here is accurate, some is not.

A driver goes into the port, ( this usually means that the driver is going to a container terminal, i.e. Cosco, LBCT, etc ) stops at a " pedestal " picks up a handset and tells the shipping office information, ( carrier, container number & load number ) then the pedestal spits out a card ( kind of like the one you get at a toll booth ) the card may or may not say what length chassis is needed for the container ( terminals are run like a little fiefdom where every king runs his show the way he wants to ) the card will say that the container is on a " row " and it is in a " stack " .

So the driver goes to the " pool " to look for a chassis, sometimes there is a chassis there, sometimes he has to wait for one to come in ( this could take several hours ) , so he gets a chassis and sees it needs repair, but he takes it rather than waiting longer for another one, then he looks for the row and the stack, he gets there but finds out that the crane operator is on lunch and there is only one crane operating that day because the other crane is broke down, when lunch is over ( usually 2 hours ) the yard man ( a guy that drives a pick up truck all day ) tells the driver that container is a Hanjin and the chassis that the driver has is an APM , so the driver has to go back to the pool to find a Hanjin chassis ( remember the card that was spit out at the pedestal, it just said a 40 ft chassis, it didn't say it had to be a particular one ) , so another 2 hours looking for a Hanjin chassis, now the driver thinks he has got it made, he's got the right chassis, so he goes back to the row and the stack, by now it's break time ( another hour or so ) then he waits for the crane and the yard man comes again and tells the driver that the container is not in the stack but is still on the ship and they don't know when it will be off loaded

So the driver has spent the better part of 5-7 hours puttzing around for a container that wasn't even ready to ship.

This is only part of the " efficient " system in place.

This next part is not a knock on longshoremen or unions in general. Part of that " efficiency " lies with how the union does it's job. Remember in the movie, " Cool Hand Luke " where the guard looks at luke and says : Luke, why is your dirt in boss man's ditch ? Luke then proceeds to take his dirt out of boss man's ditch and put it on boss man's yard, about an hour later the guard looks at luke and says : Luke why is your dirt in boss man's yard ? Luke then puts his dirt back into boss man's ditch and this goes on and on ( you get the picture )

You see, everyone has got their job and nobody knows how to do the other man's job and nobody would if they knew how because that would be taking their job away and that's a big no,no

So this is only a little part of the efficiency.

P.s. a place where container trains go is not called a Depot ( a Depot is where passenger trains go to pickup or drop off passengers ) container trains go to switching yards and railheads.

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