The ubiquitous shipping container recently celebrated its 68th birthday and has become the lifeblood of global trade..
Around 866 million TEUs were shipped globally in 2023 with the volume projected to reach 988 million TEUs by 2027..
As we know, there are several different types of containers in the container fleet of the various shipping lines..
- Dry Van or General-Purpose Containers (Standard & High-Cube)
- Open Top Containers (Soft Top & Hard Top)
- Flat Rack Containers (Fixed End, Collapsible/Platform, Super-Rack)
- Tank Containers
- Refrigerated (Reefer) Containers
- Side Door Containers
- Bulktainers
- Various other custom containers
The wide spectrum of cargoes shipped in containers across the world on almost every container ship includes a diverse array of special cargoes such as Out of Gauge (OOG) and Refrigerated (Reefer) cargoes..
They are termed as special cargoes and special containers because these require particular attention due to their unique cargo handling, storage needs, permits, approvals, equipment, regulations, and documentation..
Out of gauge Cargo (OOG)
OOG cargo is cargo that cannot fit into a normal GP container as it exceeds the dimensions of the GP container in terms of length, width, and/or height.. (View the “generic” container dimensions)
OOG cargo is carried in Open Top containers (OT) or Flat Racks (FR), due to the nature and size of the cargo..
Open Top Containers – This type of container is used for loading cargoes that are over-high like machinery, vehicles, tyres (see below), steel coils etc..

It is also used for in-gauge cargoes that cannot be easily loaded through the door and need to be loaded from the top (like glass)..

Flat Rack Containers – Mainly used for cargo that exceeds the width (referred to as over-width) or height (over-high).. If the cargo is just over-width or over-height, fixed-end flat racks can be used where the ends of the container are fixed and cannot be folded..
There are also collapsible flat racks or platform containers where the ends of the container can be collapsed to form a platform and cargo is loaded on top of it..

Both fixed-end and collapsible flat racks are used in combination to load cargo that is over-width, over-length, and/or over-high.. Big machinery, heavy equipment, project cargo, large vehicles on tracks, boats, big reels, etc are loaded on this type of container..
Platforms are also used underdeck of the container ship to load oversized cargo across several containers, like below..

Super-racks are another type of flat rack with a difference in that in a Super Rack container, the corner posts can be extended upwards to increase the height to cater to high cargo as shown below..

Reefer (Refrigerated) Cargo
Although these cargoes and containers have become a regular feature on many container ships, reefer containers are considered special due to the many requirements for the perishable cargo carried on these containers..
A refrigerated container or reefer container is a shipping container used for the transportation of temperature-sensitive cargo..
A reefer container has its own integral and inbuilt refrigeration unit but its also relies on external power, from electrical power points at a land-based site, a container ship, or on a quay..

When transported over the road on a trailer these reefer containers are powered by generators (“gensets”) clipped onto the reefer container on road journeys..
Reefer containers are used to carry many cargoes that are sensitive to temperature changes and require a temperature-controlled environment.. Examples include Frozen Meat, Fresh Produce, Fruits, Vegetables, certain Chemicals, Photo films etc..
Reefer containers have also evolved to be smart, capable of providing real-time tracking and information relating to humidity, and temperature settings, and is also used in Cold Treatment Sterilisation for shipment of fresh produce..
Conclusion
The shipping industry’s ability to adapt to the requirements of special cargoes through technological innovations in container design is a testament to its crucial role in global trade..
Each type of special cargo and container solution exemplifies the intricate and fascinating world of global trade, shipping, freight, and logistics, highlighting the industry’s adaptability and technological advancements in facing modern shipping challenges..
Understanding the specific needs and appropriate shipping methods for OOG and Reefer cargoes not only enhances logistical efficiency but also minimizes the risk of damage, ensuring that goods arrive at their destinations safely and in optimal condition..
As global trade continues to evolve, so will the technologies and methodologies employed to transport these critical cargoes across the world’s oceans.. The industry is continually innovating to meet the demands of transporting these complex cargoes as these cargoes form essential components for many industries..
Article republished after critical updates


















It’s great and thanks a lot for sharing the knowledge.
Great Article I would like to introduce GenFlat Marine Collapsible containers
Our containers have received awards for the best innovation in the container industry
Thanks much to know shipping knowledge more about containers & others related .
I am working for handling shipping document .
I am a subscriber of your valuable blog since a couple of months ago. As a commodities trade finance consultant, I understand that some cargoes in commodities trade, such as agricultural produces etc. may need good ventilation to avoid damages during the hot and humid sea voyage. A special container providing ventilation is named “Fantainer” (with fans to provide ventilation). Please elaborate more on how the various “load plan” softwares introduced in your blog deal with proper stowage of fantainers that need to face the open fresh air in order to make ventilation possible. Certainly fantainers should not be stowed “under deck” (limited or no ventilation) or “on deck” but surrounded, blocked or “suffocated” by other near by containers.
Thanks a lot, sir
Hi, I am new to sea freight but am learning fast.
I always have problems on loading. that is given a packing list & to determine how many & type o containers to be used based on the packing list given.
Latest, i have been given to determine what type of equipment to use if packing list of
2 units of aircraft engines 197 x 100 x 115 inches weight 7000kgs/each unit & 2 units aircraft engines 232 x 100 x 120 inches weight 7000kgs/each .. which & how many flat rack to use.
Shipment destined to UK.
Thank you for your asisstance. I have been looking for sites that can assist on loading of container whether OOG or normal GP..
i’m ama,from university of colombo srilanka.thank u v.much 4 above link.i got most important things what i wanted.
I am glad i could assist Ama, pls subscribe to the site (for free) so you can keep getting more new articles and information..
What is the overall width on an OOG 40′ FR?
This is very nice for us in the shipping industry. Thanks for the website. You are now one of my favorites.
Hi thanks for above link. Are there any calculation table to know how many containers void and killed for an OOG cntrs? Thanks. Léazz
Hi Leazz, thats a difficult question to answer coz it depends totally on the vessel involved and the planning of the vessel.. The only time you will ever know FOR SURE is when the planning for the vessel is done..
Hi Leazz, i will be glad to assist..
Hi, my management gave me a project on OOG and flat racks. I need to study them and give details such as loading/discharging procedures, from one end to another, stuffing and unstuffing and so on. Could you kindly assist me please? Thanks. Léazz
what class of product can be carried by a flexitank
Hi Shafiek, flexitanks are used for the carriage of liquid cargoes.. Currently mainly wine is being carried in these flexitanks ex South Africa..
The pictures for 20’/40′ PL (platform/tweendeck/bolsters) are in fact pics of collapsible Flatracks. Platforms do not have any
end piece (collapsible or not). PL’s mainly used on RORO vessels to cater for non-wheeled cgo. True, you can in some instances use collapsed FR’s for the same purpose but generally load capacity is considerably different.
For reefer containers suggest you go into more details of the different types of reefer containers on the market today. A long way fm the original SAECS clip-ons/simple reefer boxes. One example CA (controlled atmosphere) reefers. Interested readers can check apm-maersk.com/safmarine.com websites for more info or contact PPECB.
rgds
claus