What Is an Open Top Container?
An open top container is a specialised shipping container that features a removable roof instead of the fixed steel ceiling found on standard dry containers. The roof is typically covered with a heavy-duty PVC tarpaulin supported by removable metal roof bows (arched crossbars), although some variants feature a detachable hard-top made of steel or aluminium.
This open roof design allows cargo to be loaded from above using cranes or hoists, making open top containers essential for transporting goods that are too tall, too heavy, or too awkwardly shaped to be manoeuvred through standard container doors.
Open top containers are built to the same ISO standards as conventional shipping containers, with identical external dimensions (width and length), the same corner castings, and full compatibility with ships, trucks, trains, and port handling equipment. The structural side walls, rear doors, and flooring are the same robust Corten steel and marine-grade plywood found in standard containers.
The key difference is access – and that single design change opens up an entirely different world of cargo possibilities.
Looking for open top containers in Singapore? Contact Infinex for sales and rental options.
Types of Open Top Containers
Soft Top (Tarpaulin Cover)
The most common type. A heavy-duty PVC tarpaulin is stretched over removable metal roof bows and secured with clamps, ropes, or lashing systems. The tarp can be removed entirely for crane loading and replaced to protect cargo during transit.
Best for: Oversized cargo that needs to be loaded from above; situations requiring full roof removal.
Hard Top (Detachable Roof Panels)
A less common but more secure variant featuring detachable steel or aluminium roof panels instead of a tarpaulin. The solid panels provide better weather protection and security, and importantly, hard-top containers can be stacked when the roof panels are in place.
Best for: Cargo requiring stronger protection from weather and theft; situations where stacking capability is needed.
Key Structural Components
Understanding the components of an open top container helps with proper use and maintenance.
1. Corrugated Steel Side Walls
Made from Corten (weathering) steel – the same corrosion-resistant material used in standard containers and structural engineering. The corrugated profile provides rigidity and load-bearing strength.
2. Removable Roof Bows
Metal arched crossbars that span the width of the container, supporting the tarpaulin cover. These are designed to be easily removed for top-loading and replaced before transit. Important: Shipping lines will charge fines for lost or damaged roof bows, so handle and store them carefully.
3. PVC Tarpaulin Cover
Heavy-duty waterproof sheeting that protects cargo from rain, wind, sun, dust, and saltwater spray during transit. The tarp is secured to the container frame with clamps and ropes. While water-resistant, tarpaulins are not fully weatherproof under extreme conditions – for highly sensitive cargo, additional plastic shrink wrap with drying packets is recommended.
4. Swinging Door Header
A removable metal bar positioned above the rear doors. When removed, it allows taller items to be loaded through the door opening using forklifts without height restriction from the header beam.
5. Standard Rear Doors
Conventional container doors with 4 locking bars, providing standard door access for smaller items. The door opening height is typically slightly lower than the internal height.
6. Lashing Rings
Steel rings welded to the floor, bottom side rails, and upper side rails for securing cargo with chains, straps, and wire ropes. These are critical for preventing cargo movement during transport.
7. ISO Corner Castings
Standard fittings at all eight corners for lifting, stacking, and securing the container to transport vehicles and port equipment.
8. TIR Cable System
A steel cord that passes through holes in the tarpaulin, locking the cover to the container frame. TIR (Transports Internationaux Routiers) cables are required for customs compliance – the sealed system ensures the tarp cannot be removed without breaking the customs seal, confirming cargo integrity.
9. Reinforced End Walls
The end walls are engineered to handle lateral forces during transport, particularly important since the absence of a rigid roof reduces overall structural rigidity compared to a fully enclosed container.
What Cargo Is Shipped in Open Top Containers?
Open top containers are the go-to solution for any cargo that cannot be loaded through standard container doors. Here is a comprehensive breakdown by industry.
Heavy Machinery and Equipment
- Industrial generators and turbines
- Excavators, bulldozers, and cranes
- Mining equipment (drills, rock crushers)
- Industrial presses, pumps, and boilers
- Drilling rigs
- Jet and ship engines
- Agricultural tractors and harvesters
Construction Materials
- Steel beams, columns, and structural steel
- Precast concrete panels and blocks
- Scaffolding systems
- Large-diameter pipes
- Pre-fabricated building components
- Natural stone slabs and granite
- Large glass panels
- Lumber, timber logs, and bamboo poles
Energy Sector
- Wind turbine blades and components – one of the fastest-growing use cases
- Solar panel mounting structures
- Oil and gas equipment
- Drilling rig components
Raw Materials and Bulk Cargo
- Scrap metal and recyclable materials
- Steel coils and metal sheets
- Bulk coal and ore
- Cable spools and wire drums
- Heavy-duty tyres
- Industrial drums and tanks
Other Specialised Cargo
- Boats and marine equipment
- Swimming pool components
- Large sculptures and art installations
- Military vehicles and equipment
[Need to ship or store heavy equipment? Explore Infinex’s container range or contact our team for expert advice.]
Advantages of Open Top Containers
- Accommodates oversized cargo – items too tall or bulky for standard containers can be shipped without disassembly.
- Crane loading from above – eliminates door height restrictions and enables faster loading of heavy items.
- Reduces loading/unloading time – crane operations are faster than manoeuvring large items through narrow doors.
- Eliminates disassembly costs – machinery and equipment can be shipped whole.
- Dual loading access – load from the top and through the rear doors.
- Structural durability – same Corten steel construction as standard containers.
- ISO compatible – works with all standard ships, trucks, trains, and port equipment.
- Improved ventilation – open design allows better air circulation.
- Reduces cargo damage – vertical crane loading is gentler than horizontal forklift manoeuvring.
- Cost-effective vs alternatives – significantly cheaper than break-bulk shipping or chartering specialised vessels.
- Fewer containers needed – better space utilisation for large items can reduce the total number of containers per shipment.
Disadvantages and Limitations
- Higher cost than standard containers – limited supply means premium purchase and rental prices.
- Higher shipping rates – open top freight rates are typically higher than standard container rates.
- Cannot be stacked when cargo protrudes – over-height cargo prevents double-stacking on vessels, wasting ship space and incurring surcharges.
- Tarpaulin is not fully weatherproof – less protection than a solid steel roof.
- Requires crane or hoist – specialised equipment needed at both origin and destination.
- Not all terminals equipped – some ports and inland terminals lack open-top handling capability.
- Special permits for OOG cargo – over-height loads require permits, adding cost and lead time.
- Inland transport challenges – bridge and tunnel clearance issues for tall loads; may require special routing and safety escort vehicles.
- Roof bow management – lost or damaged bows incur fines from shipping lines.
- Higher securing costs – lashing, blocking, and bracing oversized cargo requires more time and materials.
Open Top vs Standard Dry Container
| Feature | Open Top Container | Standard Dry Container |
| Roof | Removable tarpaulin or hard-top | Fixed solid steel roof |
| Loading Access | Top + rear doors | Rear doors only |
| Maximum Cargo Height | Can exceed container height (OOG) | Limited to internal height |
| Weather Protection | Partial (tarpaulin) | Full seal (steel roof) |
| Stackability | Limited (cannot stack if cargo protrudes) | Fully stackable |
| Cost | Higher (rarer, premium freight rates) | Lower (standard rates) |
| Availability | Less common | Widely available |
| Loading Equipment | Requires crane/hoist for top loading | Standard forklift |
| Best For | Oversized, heavy, awkward cargo | Standard boxed/palletised goods |
| Ventilation | Superior (open design) | Limited |
| Security | Tarpaulin + TIR cable | Steel doors + seals |
Open Top vs Flat Rack Container
| Feature | Open Top Container | Flat Rack Container |
| Side Walls | Full solid steel side walls | No side walls |
| Roof/Top | Removable tarp or hard top | Completely open |
| End Walls | Fixed end wall + doors | Often collapsible |
| Weather Protection | Moderate (tarp covers) | None / minimal |
| Loading Access | Top and rear doors | 360-degree (all sides + top) |
| Cargo Containment | Walls contain loose items | Cargo can shift/fall off |
| Width Flexibility | Limited to 8 ft internal | Can accommodate wider loads |
| Structural Support | Higher (walls provide bracing) | Lower (no wall support) |
| Best For | Tall cargo within standard footprint | Extremely wide or long cargo |
| Ideal Position | Middle ground between standard and flat rack | Most open option for maximum flexibility |
Choose an open top when your cargo is too tall for a standard container but fits within the standard 8-foot width. Choose a flat rack when your cargo exceeds the width or requires side loading.
How to Choose the Right Open Top Container
Ask yourself these four key questions:
- Does your cargo exceed the door opening height of a standard container? If yes, you need top-loading capability – an open top is the right choice.
- Does your cargo fit within an 8-foot width? If yes, an open top works. If it exceeds this width, consider a flat rack instead.
- Can your cargo withstand tarpaulin-level weather protection? If yes, proceed with an open top. If your cargo is extremely weather-sensitive, consider additional protective packaging or a hard-top variant.
- Are cranes or hoists available at both origin and destination? If not, you may need to arrange specialised handling equipment or reconsider your loading plan.
Not sure which container type suits your needs? Infinex’s team can advise on the best solution. Explore our services or get in touch
Frequently Asked Questions
What is an open top container used for?
Open top containers are used for shipping cargo that is too tall, too heavy, or too bulky to load through standard container doors. Common cargo includes heavy machinery, construction steel, industrial equipment, wind turbine components, and large vehicles.
Can you stack open top containers?
It depends. If the cargo is within the container’s walls and the tarpaulin (or hard top) is in place, the container can be stacked. However, if cargo protrudes above the walls (out-of-gauge), the container cannot be stacked, which incurs additional shipping surcharges.
Is an open top container waterproof?
The PVC tarpaulin provides good water resistance but is not fully weatherproof like a solid steel roof. For highly sensitive cargo, additional protective packaging (shrink wrap, desiccants) is recommended.
How much does an open top container cost?
Prices vary by size, condition, and location. A 20ft open top typically ranges from US$2,765 to 5,142, while a 40ft ranges from US$5,124 to 7,116 depending on the market.
What is the difference between an open top and a flat rack container?
An open top has full side walls and a removable roof, while a flat rack has no side walls or roof. Open tops are better for tall cargo within standard width; flat racks are better for extremely wide or long cargo requiring multi-directional access.
Do open top containers cost more than standard containers?
Yes. Due to limited supply and specialised handling requirements, both purchase/rental prices and freight rates are higher for open top containers compared to standard dry containers.
What is out-of-gauge (OOG) cargo?
OOG cargo is any item that exceeds the standard dimensions of a container – in the case of open tops, cargo that protrudes above the container walls. OOG shipments require special handling, permits, and incur additional surcharges.
How do you secure cargo in an open top container?
Using the built-in lashing rings on the floor and side rails, cargo is secured with heavy-duty chains, straps, or wire ropes. Blocking and bracing with timber prevents lateral movement. All securing must comply with IMO guidelines.