In all seriousness, lives are at stake and safety begins with you.
This is why the IMO is putting a foot down and implemented VGM (Verified Gross Mass) rules prior to cargo export. VGM standard requires that the container is weighed and declared prior to stowage.
Here is how you can do your part to ensure the safety of your cargo and more importantly the safety of the souls that risk their lives handling your cargo. Let us go through 10 best practices of cargo container loading
1. Understand the container structure
Like any structure, the cargo container has strong points that are fortified to withstand cargo load and have weak points that function as protection against external forces.
We have to know the structural build of a container in order to ascertain if the cargo can even withstand the load of the cargo.
As you can see with the image above, credited to Hapag Lloyd, the area that bears the brunt of the load is the container floor.
The container floor is heavily fortified with rows of bottom cross supports. Also, the corner posts are also sturdy as it is built as part of the structure of the container floor.
The weak points of the container are the sidewall panels and the roof panels. So, your cargo should not be supported by the container sidewalls or be overly close to the roof panels.
2. Choose the right Container Size for your cargo
If we look that the maximum load capacity of a 20’ footer container and a 40’ footer container, the latter container although double in cubic meter capacity, does not have double the payload capacity.
|Container Type||Load Capacity|
|20’ Container||25,000 kgs|
|40’ Container||27,600 kgs|
Simply because, the structure of the containers is made of the same material, and the architecture of the containers is similar as well.
A 40’ container is not fabricated with extra steel rows at the bottom to bear heavier weights.
If we look at the bottom of a 40’ container, in fact, the only fortification made is with a “gooseneck tunnel” simply to stop the container from slacking.
So, even though your cargo can fit in a 40’ container, if your cargo is very dense and heavy, consider using 2 20’ containers for cargo transportation.
3. Be aware of the effect of Inertia
Sea voyages can be violent, vessels move at all axes and shifts the cargo inside the container. Inertia is the tendency of an object to remain in its existing state unless the state is changed by an external force.
have you ever been on a bus where it abruptly stops and your body jerks forward before you catch yourself? Your state is similar to the state of cargo in a container as well.
So, during cargo container loading lashing and stuffing, you need to anticipate that the forces of inertia during sea voyage come from all axis angles. This is the sea we are talking about; inertia comes from every angle.
Your lashing, stuffing, and choking of the cargo have to be ready for the inertia. Some cargo lashing only addresses the horizontal forces but neglects the vertical forces of inertia. If that is the case, it will be like sitting on a roller coaster with the seatbelt only securing your ankle, your body is going to sway everywhere.
4. Weight Distribution, weight distribution…
When I started working as a restaurant waiter, I once carried hot beverages on a tray, and I was ambitious so only wanted to make one trip to serve 20 tables.
One by one, I served cups of hot beverage from the tray, until most of the cups left are placed on the left of the tray.
The weight was heavily listed on one side until I couldn’t hold it and dropped all the glasses on one customer. Nobody got hurt though.
You can see my point here; you need to distribute your cargo weight as evenly as possible to avoid the container from listing to one side.
Here are some other techniques used that help distribute the weight during container loading in order to not damage the cargo and the container.
4.1 Use mid-height flooring
In cargo stacking, we should try to distribute the weight evenly during container loading.
For example, when loading a container with drums or barrels. It is advisable to load cargos on pallets first before stuffing the container. Because it not only eases the process of unloading but distributes the load of the top stack.
Damages to the whole container can happen with only one compromised barrel at the bottom, the cargo then becomes like a tower of Jenga, collapsing from above.
4.2 Do not stack heavier cargos on top
I am not sure if this point needs more elaboration. To give an example, the pyramid is easily the sturdiest building structure, as the bottom to the pyramid is wide therefore providing a strong foundation to the structure.
In cargo loading, it is not so dissimilar a case if we imagine that loading a container with the heaviest cargo on top is like building an inverse pyramid. It wants to fall one way; Down.
4.3 Place Heavy Cargos at the Center
It is the same concept as placing beverages on the tray. The most stable part of the cargo is always going to be in the center.
5 Understanding your cargo characteristics
As the rule of physics apply, your cargo state changes as external forces are introduced, it can be gravity force, temperature, humidity, and many more factors. Understanding your cargo’s inherent characteristics and its response to external force, will determine your cargo loading and stuffing procedures.
5.1 Dangerous Goods
We addressed this issue at length in this blog post here, the gist of it is that we have to adhere to strict IMDG codes set out by the International Maritime Organization (IMO) and they have rules with regards to:
- Dangerous Goods Segregation – whether one DG Cargo can be stored together with another
- Labelling and Placard – placing noticeable labels for the view of cargo handlers
- IBC instruction – Cargo packaging instructions
- DG Class – Dangerous Goods class types
5.2 Cargo Fumigation
Cargo Fumigation is a form of containing an infestation of bacteria or pest due to the temperature control of the environment. Fumigation is specifically used to treat termites from wooden cargos or wooden pallets.
Of course, cargo fumigation is not the only method of germ-killing, some cargo such as coffee beans are for human consumption, therefore, fumigation may spoil the cargo. Health and safety departments will look for other signs of bacteria control measures taken by the shipper. For example, pallets can be heat treated or alternative materials like plastic pallets can be used.
6. Be aware of void spaces between cargos
When palletized cargo is loaded into a container, inevitably there will be spaces between pallets. Spaces are not good news as there is room for the cargo to maneuver around.
You can either fill the spaces between the pallets with inflatable bags or dunnage, or you can string wrap the cargo on the pallet securely.
7. Practice Proper Cargo Lashing
There is a Goldilocks range of cargo lash tightness. Too loose and the cargo may not be secure enough, too tight and the lash may not be able to bear the stress and snap. The lash compression should be tightened without any tools assisting, it should be tightened by hands only (standard hand force of 50 daN/50kgs)
You also have to be aware of the type of lash used and it’s lashing capacity, big and heavy cargo requires stronger lashes.
8. Ensure Container Seaworthiness
You don’t get to choose the container the shipowners or NVOCCs provide you beforehand. However, you can reject the cargo if it is not perceived to be seaworthy. Here is a checklist of things you should inspect of the cargo
- Floorboard should not be listing and should be clean and sturdy
- Container Joint, Hinges, Levers, corner posts and Seals are in free of rust and seaworthy
- No holes on the roof of the container
- No obvious bents and damages on the side of the container
- No excessive rusts that may compromise the structural integrity
- No obnoxious odors,
- Container CSC plate indicating the year of the last service is within tolerance
You have the right to reject the container and request for a seaworthy container if the given container does not fit your requirements.
9. Outsource to Container Stuffing Expert
There are experts who help inspect, survey, supervise the cargo lashing quality. If your cargo is exceptional and requires extra care in securing the cargo, it is best to outsource this to the expert. The lashing certificate provided by the experts can also help you in case of any damage insurance claims to prove that there is no negligence in cargo stuffing.
10. Use Container Loading Softwares
Cargo Consolidators use a cargo loading software and algorithm to formulate a cargo loading plan. This eliminates guesswork and reliance on experience. The reason why cargo consolidators use cargo planning software is that their cargos are mostly heterogeneous and they will always try to maximize profits by utilizing container spaces efficiently.
Bringing it all together
In the name of safety, this process cannot be taken lightly. The IMO will only get stricter with regards to safety as the container vessels get larger.