Wednesday, May 29, 2024
shipping and freight resource services
HomeShipping and FreightShould i use Open Top or Flat Rack for over-height cargo

Should i use Open Top or Flat Rack for over-height cargo

Sounds like a trick question..?? It could be..!!

Generally open top and flat rack containers are used for loading cargo that are

  1. difficult to load through the doors of a standard gp container
  2. are above the dimensions of a standard gp container (out of gauge)

Below is the external view of an open top and a flatrack.. (Click on the image to view the bigger version)


When you remove the tarpaulin (the outer cover) on an open top or open the doors , you will see what is called as “roof bows” inside the container as per below image (s)

These roof bows are there not only to support the tarpaulin, but they also add to the structural strength/integrity of the container and its stability.. Imagine a heavy cargo that is loaded without the roof bows.. There is a possibility that the container could buckle without the roof bows to strengthen the top of the container..

Therefore if you are loading heavy and over high cargo and there is no possibility of leaving most of the roof bows as it is, it is suggested that a flat rack be used in order not to compromise on the safety and structural integrity of the container..

Do you agree..??

Above images downloaded from,,

Liked the content..??

Sign up below to receive the best and most reliable industry content for free from THE Definitive Online Resource for Shipping and Freight..




Hariesh Manaadiar
Hariesh Manaadiar
I am Hariesh Manaadiar, the Founder of Shipping and Freight Resource.. I have been in the dynamic shipping and freight industry for over three decades and have worked in several sectors.. I share my experiences and knowledge of the industry through this blog for those looking for help in the industry.. Stay subscribed for more free useful content about shipping, freight, maritime, logistics, supply chain and trade..


  1. Hi Good day.

    What is the best way to move the below oversize cargo?
    8 Pallets with each pallet weighted at 3200 kgs and the each pallet size at (L)425 cm x(W) 325 cm x (H) at 55 cm?

  2. Hi, how far out the cargo from the 40ft flat rack can stick out? I am planning to ship 40ft container chassis inside a 40ft flat rack. Since the chassis are longer than flat rack, I was wondering what are the regulations? Any help is greatly appreciated.

    • Hello Pratap, that would really depend on the ship, the route and where cargo will be stowed on the ship.. There is no hard and fast rule on the protrusion.. There are cases where a few collapsible flatracks are placed side by side and big cargoes such as turbines, propellers etc are loaded..

      The shipping line would be the best people to advise you of this, but that would be dependant on that particular ship you want to load it on.. But if your chassis is exactly 40′ in length then you would need a 40′ Collapsible flat rack as a fixed end flat rack will not assist you.. Since the cargo and container both are 40′ there shouldn’t be much of a protrusion..

  3. Hi, what would be a good guide based on cargo dimension on using open top container ? for example, when doing quotation, technically a particular cargo say 8m long and width / height are within gauge. While it fits the 40 GP nicely but operationally not possible to pushing it through the 40 GP door else it damage the flooring. Would it be a good guide to say anything more than 3ton and long length say 5m and longer to use open top instead of 40 GP ?

    • Hi Yong, there is no hard and fast guide on this.. This decision will depend totally on the type of cargo and how it is loaded into the container.. For example even if the cargo is longer than 5 m and above 3 tons, but is loaded on wheeled frames and can be loaded by pushing into the container and the brakes are locked and lashed properly, there is no requirement to use an open top..

      So the decision whether OT or FR or GP is used will depend on the cargo type, loading/offloading equipment available and also the clients experience in handling such cargo previously..

      Trust this assists..

  4. What would be the % cost difference of disassembling and loading into two 40′ containers, compared to leaving a piece intact and shipping on a flat rack. the piece being 60,000#.

    • Hi Sanjeev, collapsible flatrack needs to be used only if the cargo is over LENGTH and not if it is over WIDTH.. Also as the title of this post mentions, cargo is over-high – neither over length nor over width..

  5. You have the option of out of gauge depending the load or if you are lodaing Giraffes thats another story

  6. Yes, I do agree. Using OT unit without using roof bows can cause structural intergrity/strength. Best option is to use FR unit but this depends on the height of the cargo.

  7. to decide which container to use ,it is usefull to know the actual height of your cargo ,
    open tops can be shipped wthout the tarpaulin cover but for securing heavy cargo a flatrack ‘s lashing points have a higher strength rating .
    You can send the dimensions and i will happily advise and even give you a comparative costing .rgds owen


Please enter your comment!
Please enter your name here

This site uses Akismet to reduce spam. Learn how your comment data is processed.



Sign up below to receive the best and most reliable industry content for free from THE Definitive Online Resource for Shipping and Freight..



FBX - Freight Indices