Flat Rack Shipping Containers: When to Use Them


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Standard shipping containers can serve as industrial, commercial, and residential structures. In addition to these conventional units, there are several types of special-purpose containers that serve niche applications. That list includes flat rack shipping containers, which are ideal for transporting oversized cargo.

Below, we’ll explore flat rack containers, what makes them unique, and how they can help your business.

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What Is a Flat Rack Shipping Container?

Flat racks are containers with walls only along the shorter end (width) of the container surface.

These ends can either remain fixed or have collapsible walls that further simplify loading and unloading.

They find their application in transporting bulky cargo with unusual dimensions. Since they have no side walls, you can load heavy cargo in flat rack units from both the top and longer end (length).

Common Cargo and Goods Shipped in Flat Rack Containers

Flat rack shipping containers help transport goods that cannot fit in a standard container due to their weight or abnormal size.

As side walls are absent in a flat rack unit, oversized items generally stick out from the open sides during transportation.

These are some of the typical cargo that you can transport using a flat rack container:

  • Heavy Machinery
  • Boats and marine vehicles
  • Timber
  • Pipes
  • Cars
  • Buses
  • Trucks
  • Construction vehicles
  • Turbine blades
  • Boilers
  • Power generators
  • Jet or Turboprop Engines

Transporting a bulky industrial item using flat racks.jpg


Types of Flat Rack Containers

Flat racks come in two varieties: Collapsible Flat Racks and Non-Collapsible Flat Racks.

Non-Collapsible Flat Rack

Non-collapsible shipping containers have fixed ends on either side. The thick end walls help improve the construction strength of the container, allowing you to transport heavier loads.

They have a higher top load capacity compared to collapsible containers.

Collapsible Flat Rack

Collapsible shipping containers have walls that open up along the shorter end, giving you an entirely flat, rectangular surface. With collapsible walls, you can store and ship empty containers more efficiently. You can stack these containers like a 'rack' or position them sideways in a regular container.

Four stacked collapsible flat racks take up the same area as a standard shipping container, which means they provide incredible opportunities to save on space.

Flat Rack Container with Collapsible Ends.jpg

Both flat rack containers have support accessories like lashing rings, winches, belts, and stanchions that provide secured support to the cargo. These accessories have a load-bearing capacity of about 4500 lbs. for a 20 ft. container and 8,800 lbs. for 40 ft. open-top containers. Usually, these support units exist on the side railing, floor, or container corners.

Forklift pockets are generally a part of the standard accessories. While most containers have softwood/timber flooring, you can also use containers with a steel floor. In addition, some container providers add gooseneck tunnels to enable safer transportation.

You can also contact your container manufacturer for a custom container with unique dimensions to transport oversized cargo or handle goods with irregular sizes.

Dimensions of Flat Rack Containers

Flat rack shipping containers come in two sizes as per ISO-industry standards: 20-foot and 40-foot.

Both containers vary slightly in their external width, internal width, and height. Length is the only area in which they differ. Naturally, a 40' flat rack offers higher storage capacity, while 20' units are more compact.

We've listed the specifications of these units to help you pick a suitable container for your application.



20-foot Flat Rack Containers

40-foot Flat Rack Containers

External Length

20 ft. / 6.1 m

40 ft. / 12.2 m

Internal length

19.5 ft. / 5.94 m

39.8 ft. / 12.13 m

Internal width

7.7 ft. / 2.35 m 

7.9 ft./ 2.40 m 

Internal height

7.7 ft. / 2.35 m 

2.14 m / 7 ft

Tare weight

5,203.8 lbs / 2,360 kg

11,025 lbs / 5,000 kg

Payload capacity

66,458.7 lbs / 30,140 kg  

88,200 lbs / 40,000 kg 

Cubic Volume

1,154.3 cu. ft. / 32.7 m3 

2,195.7 cu. ft. / 62.2 m3


Uses of Flat Rack Shipping Containers

The absence of side walls in flat rack containers makes them ideal for transporting loaded cargo, which may otherwise be challenging to load through the end doors. You can pack various types of heavy goods through the open-end walls and the roof with a crane.

Another exciting application of a flat rack is shipping machinery and heavy vehicles as a whole.  With a flat rack shipping container, you can avoid the hassle of assembling and disassembling heavy steel equipment stacked together.

Flat rack containers with loaded steel sheets.jpg


How to Select the Best Flat Rack Containers

Flat rack containers are advantageous for shipping machinery and other large items. That said, the removal of the side walls reduces the structural strength of the container. These containers require additional support members to ensure that the ends do not bend or crack.

Stress can also build-up at the corners during transportation, which can result in bent edges or sudden failures. On the other hand, if the base surface is too rigid or brittle, the container may snap into two parts.

With that, it’s crucial to analyze the cargo size, weight, and loading direction. The orientation and distribution of load will vary depending on the cargo weight and space constraints.

Always select a flat rack container with a higher stress-bearing capacity than the weight of the shipped goods. Choosing a larger container can prove beneficial since it makes it easier to evenly distribute the load. If you feel your container is inadequate, talk to your shipping container provider about additional support accessories.

Loading a bus for export on a rack container flat.jpg


Flat rack shipping containers offer a convenient solution for handling heavy items with unusual dimensions. Their versatile configuration also makes them easy to store. Still, you should consider the size and weight of the goods for transportation before investing. Remember, flat rack containers have lower strength-bearing capacity than conventional shipping containers.

Mobile Modular Portable Storage is the leading supplier of high-quality shipping containers for rent and sale. Call us on 866-459-7600 or get in touch with us to learn more about industry-specific container solutions.



What Is a Flat Rack Shipping Container?

Flat rack shipping containers are open units with walls only at the shorter ends. You can use them to store or ship heavy items with irregular dimensions that are difficult to load through the front/end doors.

What Is the Width Of a 40' Flat Rack Container?

The internal width of 40 foot flat rack shipping containers is about 7.9 ft. or 2.40 meters.

What Is a Collapsible Flat Rack Container?

Collapsible containers have foldable walls at both ends that you can detach or fold down to the base on the container when the unit is not in use.

Are Flat Rack Containers Stackable?

Flat racks with collapsible ends are highly stackable, allowing you to easily store four flat rack containers in the same space as a single standard container.

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