Differences Between Open Top, Open Side and Flat Rack Containers
In modern global logistics, shipping containers are the backbone of the entire maritime, rail, and road transport system. Standard closed containers (dry containers) handle most common shipments, but there is a wide range of cargo that, due to dimensions, weight, or specific handling requirements, does not fit into these containers. Therefore, specialized types of containers were developed that allow the transport of even the most demanding shipments – and it is precisely these solutions that we will address in depth in this glossary.
Types of Specialized Containers: Open Top, Open Side, and Flat Rack
This article provides a detailed analysis of three key types of containers that are essential for transporting oversized or non-standard goods:
- Open Top container – for tall cargo and goods loaded from above
- Open Side container – for wide or awkward cargo with the need for easy side access
- Flat Rack container – for extremely heavy, wide, and tall cargo, where maximum flexibility is the priority
Open Top Container: Specialist in Top Loading
Detailed Description and Construction
Open Top container is a variant of a standard container that allows loading and unloading of goods from above – typically by crane. This container has four solid walls and a floor, but its roof is made of removable steel arches (roof bows) and a robust waterproof tarpaulin that protects the cargo from rain and dust. On most models, the upper crossbar above the doors (door header) can also be removed, which significantly facilitates handling of tall objects.
Technical Specification:
| Type | Length (interior) | Width (interior) | Height (interior) | Max. Capacity* |
|---|---|---|---|---|
| 20′ Open Top | approx. 5.90 m | approx. 2.35 m | approx. 2.35 m | 21–28 t |
| 40′ Open Top | approx. 12.03 m | approx. 2.35 m | approx. 2.35 m | 26–30 t |
*Maximum capacity depends on the specific manufacturer and design.
Key Structural Elements
- Removable roof arches: Provide structural strength, can be removed before loading.
- Robust tarpaulin: Secured around the perimeter with lashing cables, usually made of PVC, protects goods from weather.
- Double-leaf doors: Same as standard containers, allow classic side loading.
- Interior lashing eyes: On the floor and walls for secure cargo securing.
Typical Uses
Open Top containers are key for:
- Cargo exceeding the height of a standard container (machinery, technological equipment, sculptures)
- Goods requiring top loading/unloading by crane (e.g., heavy construction machinery, stone blocks, steel pipes, big bags)
- Bulk materials packed in bags
- Long objects that can only be stacked from above
Advantages and Disadvantages
Advantages:
- Top loading capability allows transport of tall or difficult-to-handle items
- Better cargo protection than flat racks, thanks to side walls and tarpaulin
Disadvantages:
- Limited width (cannot transport extremely wide cargo)
- If cargo exceeds container height (out-of-gauge load), transport is more expensive and container stacking is not possible
Safety Aspects
- The tarpaulin must always be properly secured to prevent it from being torn by wind or cargo damage
- Cargo must be perfectly secured against movement in the container (use of lashing eyes, lashing straps)
- In case of OOG cargo transport, it is necessary to inform the carrier and port of special handling
Open Side Container: Maximum Access to Cargo from the Side
Detailed Description and Construction
Open Side container (also called side door container) is a specialized container with large folding or sliding doors along the entire length of one of the side walls. It thus provides absolutely convenient access to all parts of the cargo and facilitates handling of hard-to-reach or palletized goods.
Technical Specification:
| Type | Length (interior) | Width (interior) | Height (interior) | Max. Capacity* |
|---|---|---|---|---|
| 20′ Open Side | approx. 5.88 m | approx. 2.33 m | approx. 2.36 m | 21 t |
| 40′ Open Side | approx. 12.00 m | approx. 2.33 m | approx. 2.36 m | 26 t |
*Maximum capacity may be several hundred kg lower due to reinforced frame construction.
Key Structural Elements
- Folding/sliding side doors: When opened, provide access to the entire length of the container
- Reinforced frame and floor: Compensate for the absence of a solid side wall, ensure stability even when fully loaded
- Standard double-leaf doors: Remain on the shorter side of the container
- Lashing eyes: For secure cargo securing during transport
Typical Uses
Open Side containers are ideal for:
- Wide, awkward, or bulky goods that cannot be inserted through standard doors
- Fast loading/unloading of palletized goods with a forklift
- Mobile shops, exhibition stands, cafes, construction site warehouses
- Transport of vehicles requiring side handling
Advantages and Disadvantages
Advantages:
- Maximum access to cargo along the entire length – ideal for logistics with high speed and efficiency requirements
- Reinforced construction provides a high degree of safety
Disadvantages:
- Higher purchase and transport costs than standard containers
- Due to more complex construction, capacity may be slightly lower
Safety Aspects
- Side doors must be properly locked during transport
- Cargo must be carefully secured against shifting, use of lashing systems and protective strips is recommended
Flat Rack Container: Platform for Extreme Loads
Detailed Description and Construction
Flat Rack container is an open robust platform with two end walls (on the shorter sides), which is designed for transport of large, extremely heavy, or non-standard cargo. Side walls and roof are completely absent, which allows transport of goods exceeding the width or height of a standard container.
There are two basic types of flat racks:
- Fixed-end Flat Rack – with fixed end walls, suitable for heavier loads, provides greater strength
- Collapsible Flat Rack – collapsible end walls to save space on return transport of empty containers (up to 4–5 empty flat racks can be stacked on top of each other)
Technical Specification:
| Type | Platform Length | Platform Width | Height of End Walls | Max. Capacity* |
|---|---|---|---|---|
| 20′ Flat Rack | approx. 5.94 m | approx. 2.23 m | approx. 2.23 m | up to 31 t |
| 40′ Flat Rack | approx. 12.13 m | approx. 2.23 m | approx. 2.23 m | up to 45 t |
*Capacity depends on type and construction.
Key Structural Elements
- Highly durable steel floor: Designed for extreme point loads, often with wooden planks for better traction
- End walls: Fixed or collapsible, serve to secure cargo and increase safety
- Absence of side walls and roof: Allows transport of even the widest and tallest cargo
- Large number of lashing eyes: For secure fastening of even the largest machinery
Typical Uses
Flat Rack containers are essential for:
- Construction and agricultural machinery (excavators, bulldozers, tractors, cranes)
- Industrial machinery, turbines, generators, production lines
- Large vehicles, ships, yachts
- Steel structures, piping, long beams, and profiles
- Unique project cargo (equipment for energy, mining, bridge construction, etc.)
Advantages and Disadvantages
Advantages:
- Maximum flexibility – ability to transport oversized cargo (OOG)
- Extreme capacity and robustness
- Collapsible variants economical for return transport
Disadvantages:
- Minimal protection from weather – goods must be wrapped separately
- Higher transport costs (takes up more space, special handling in ports)
- Requires experienced personnel for loading and cargo securing
Safety Aspects
- Cargo must be thoroughly secured (lashing chains, straps, wooden wedges)
- Use of protective elements against abrasion and damage during handling is recommended
- In case of OOG cargo transport, special permits and route planning are necessary
Comparison: Open Top vs. Open Side vs. Flat Rack
| Feature | Open Top | Open Side | Flat Rack |
|---|---|---|---|
| Construction | Solid walls, open roof with tarpaulin | Solid walls, side doors along entire length | Open platform, 2 end walls |
| Loading | From above by crane, from rear | From side and rear | From above, side, rear |
| Cargo Protection | Side protection, tarpaulin from above | Full protection (when closed) | Minimal, must be wrapped |
| Capacity | 21–30 t | 21–26 t | up to 45 t |
| Ideal For | Tall cargo | Wide objects, fast handling | Extremely heavy, wide/tall cargo |
| Transport Costs | Higher than standard | Higher than standard | Highest (OOG surcharges) |
| Common Use | Machinery, pipes, blocks | Pallets, mobile stands, vehicles | Construction machinery, industrial equipment |
How to Choose the Right Container Type? – Expert Guide
Decision-making by cargo type:
- Height: If cargo exceeds the height of a standard container and needs side protection, choose Open Top.
- Width: For wide objects that can be inserted from the side, Open Side is ideal.
- Extreme dimensions/weight: Flat Rack is the only option for OOG cargo.
- Weather sensitivity: Consider the level of protection – Flat Rack requires its own wrapping, Open Top provides tarpaulin protection.
Practical Tips:
- Always consult specific parameters with the carrier before ordering (not all companies have all container types in stock)
- For OOG cargo, expect higher fees (port handling, special permits, inability to stack)
- Ensure proper securing and wrapping of cargo, especially on flat racks
Real-World Scenarios from Practice
- Construction company needs to transport an excavator with a height of 3.2 m – chooses 40′ Open Top, because the excavator does not fit into a standard container in height, but needs side protection.
- Turbine manufacturer transports a machine weighing 34 t and 2.8 m wide – the only option is 40′ Flat Rack, because both width and weight exceed the limits of standard containers.
- Mobile cafe wants to quickly load all interior equipment – uses 20′ Open Side, because it allows easy insertion of equipment with non-standard dimensions.
Frequently Asked Questions and Expert Answers
Can I transport extremely heavy machinery in an Open Top container?
- Open Top has high capacity, but is not designed for point loads like Flat Rack. For extreme weights and heavy machinery, we recommend Flat Rack.
Is Flat Rack suitable for goods sensitive to rain?
- No, Flat Rack has no side or top protection. Special wrapping must be used, or choose Open Top if tarpaulin protection is sufficient.
Czech Republic, Třebíč 
FREE SHIPPING 
Other container news...
Grid – ABS Vent Cover
The ABS Vent Cover is a key structural element found on the outside of standard dry vans. Its main function is to allow passive air exchange between the interior and exterior of the container.
Faults and Most Common Defects of Refrigerated Containers
Refrigerated (freezer) containers are the backbone of safe and efficient transport of temperature-sensitive goods. Thanks to modern technologies, consistent maintenance and remote monitoring, their failure rate can be significantly reduced. The most common defects – from temperature fluctuations to mechanical and electrical failures to human errors – can be solved through systematic prevention, regular inspections (PTI), operator training and the use of telematics.
Anatomy of a 45’HC PW Double Curtain Side Shipping Container
The 45’HC PW Double Curtain Side container represents the pinnacle of intermodal container innovation for the European market. Its unique combination of high capacity, fast loading/unloading and full compatibility with sea, rail and road transport makes it the ideal choice for forwarders, manufacturers and distributors who want to maximize the efficiency of their logistics flows. Its design reflects the needs of the modern supply chain, where speed, flexibility and maximum use of loading space are key.
Shipping Container Homes
Shipping container home is a residential unit created from one or more steel intermodal shipping containers that have been structurally modified, insulated, and equipped with technical systems to meet the requirements for safe and comfortable living.