Beyond the standard dry shipping container, the logistics industry relies on a variety of specialized container types designed for specific cargo needs. Understanding these options helps you choose the right equipment, avoid costly mistakes, and ensure your cargo arrives safely.
This guide covers every major container type, their specifications, ISO codes, and when to use each one.
The ISO Container Standard System
The International Organization for Standardization (ISO) established container standards in 1968, revolutionizing global shipping. The ISO 668 standard defines the classification, dimensions, and ratings of intermodal containers.
- Containers fit precisely on ships, trains, and trucks worldwide
- Crane and handling equipment work with any ISO container
- Global trade becomes predictable and efficient
- Costs are reduced through interoperability
Standard Dry Containers
The workhorses of global shipping, standard dry containers handle the majority of general cargo. Available in three main sizes:
| Size | Length | Internal Volume | Max Payload | Common Use |
|---|---|---|---|---|
| 20' Standard (TEU) | 6.06m (19'10") | 33.2 m³ | 28,280 kg | Heavy goods, dense cargo |
| 40' Standard | 12.03m (39'5") | 67.7 m³ | 26,780 kg | General freight, balanced loads |
| 40' High Cube | 12.03m (39'5") | 76.3 m³ | 26,500 kg | Light, voluminous cargo |
| 45' High Cube | 13.56m (44'5") | 86.1 m³ | 27,700 kg | Maximum volume needs |
Refrigerated Containers (Reefers)
Best For: Temperature-Sensitive Cargo
Pharmaceuticals, frozen food, fresh produce, dairy products, flowers, and any cargo requiring climate control.
Reefer containers feature built-in refrigeration units that maintain precise temperature control throughout the journey. They're essential for cold chain logistics.
| Feature | 20' Reefer | 40' High Cube Reefer |
|---|---|---|
| Internal Length | 5.44m (17'8") | 11.56m (37'11") |
| Internal Volume | 28.3 m³ | 67.3 m³ |
| Temperature Range | -25°C to +25°C | -25°C to +25°C |
| Power Required | 380-460V, 3-phase | 380-460V, 3-phase |
| Insulation Thickness | 75-100mm | 75-100mm |
- Thick insulation walls (75-100mm)
- Refrigeration unit at one end (reduces length by ~2 feet)
- T-floor decking that raises cargo 75-100mm for air circulation
- Required air gaps on all sides (minimum 100mm)
Open Top Containers
Best For: Oversized Height Cargo
Machinery, timber, large equipment, marble slabs, and any cargo that can't fit through standard doors.
Open top containers feature a removable tarpaulin roof supported by removable roof bows, allowing cargo to be loaded from above using cranes.
| Feature | 20' Open Top | 40' Open Top |
|---|---|---|
| External Dimensions | Same as standard 20' | Same as standard 40' |
| Roof Type | Removable tarpaulin | Removable tarpaulin |
| Max Height Advantage | Cargo can exceed container height | Cargo can exceed container height |
| Payload | ~200kg less than standard | ~300kg less than standard |
- Top loading capability for oversized items
- Flexible height - cargo can project above container
- Easier loading of heavy, bulky items with overhead cranes
Flat Rack Containers
Best For: Heavy Machinery & Out-of-Gauge Cargo
Construction equipment, vehicles, boats, large pipes, project cargo, and items that exceed standard container dimensions.
Flat racks feature a strong floor with no side walls (or collapsible sides), designed for cargo that can't fit in enclosed containers.
| Feature | Specification |
|---|---|
| End Walls | Fixed or collapsible (for storage efficiency) |
| Floor Rating | Heavy-duty, rated for concentrated point loads |
| Lashing Points | Every 300mm (12 inches) along the sides |
| Width Capacity | Can exceed standard container width when sides folded |
| Typical Payload | 45,000 - 50,000 kg (depending on configuration) |
Tank Containers (ISO Tanks)
Best For: Liquid Cargo
Chemicals, food-grade liquids (wine, oils), liquefied gases, and hazardous materials requiring specialized containment.
Tank containers consist of a cylindrical stainless steel tank within a standard container frame, enabling safe transport of liquids via the same intermodal infrastructure.
| Specification | Standard ISO Tank |
|---|---|
| Capacity | 21,000 - 26,000 liters |
| Tank Diameter | 1.83m (6'0") |
| Frame Size | 20' standard footprint |
| Max Payload | 24,000 - 29,000 kg |
| Pressure Rating | 1.5 - 6 bar (varies by type) |
Understanding ISO Container Codes
Every shipping container has a unique identification following the BIC (Bureau International des Conteneurs) marking system. Understanding these codes helps you quickly identify container types and specifications.
U = Equipment category (U = freight container)
123456 = Serial number
7 = Check digit
Size and Type Codes
The four-character size/type code tells you everything about the container's dimensions and type:
| Code | Length | Height | Type |
|---|---|---|---|
| 22G1 | 20' | 8'6" | General Purpose (Standard) |
| 42G1 | 40' | 8'6" | General Purpose (Standard) |
| 45G1 | 45' | 9'6" | General Purpose (High Cube) |
| 22R1 | 20' | 8'6" | Refrigerated |
| 42R1 | 40' | 8'6" | Refrigerated |
| 22U1 | 20' | 8'6" | Open Top |
| 22P1 | 20' | 8'6" | Flat Rack |
| 22T0 | 20' | 8'6" | Tank Container |
- First digit: Length (2=20', 4=40', L=45')
- Second digit: Height (2=standard 8'6", 5=high cube 9'6")
- Third character: Type (G=general, R=reefer, U=open top, P=flat rack, T=tank)
- Fourth character: Feature code (1=standard features)
Choosing the Right Container Type
| Your Cargo | Recommended Container | Why |
|---|---|---|
| General merchandise, boxed goods | 20' or 40' Standard | Cost-effective, widely available |
| Frozen food, pharmaceuticals | Reefer (20' or 40'HC) | Temperature control essential |
| Tall machinery, marble slabs | Open Top | Top-loading capability |
| Heavy equipment, vehicles | Flat Rack | No dimensional restrictions |
| Chemicals, wine, oils | Tank Container | Specialized liquid handling |
| Light, voluminous goods | 40' or 45' High Cube | Maximum volume per shipment |
Plan Your Container Load Efficiently
LoadPlanner helps you maximize container utilization regardless of container type. Calculate optimal arrangements in seconds.
Try LoadPlanner FreeCommon Mistakes to Avoid
- Using standard container dimensions for reefers - Always reduce capacity by 10-15% for refrigerated units
- Forgetting about power requirements - Reefers need continuous power; confirm power availability at all points in the journey
- Ignoring door opening constraints - Even if cargo fits inside, it must fit through the door
- Overlooking weight distribution - Flat racks and open tops require proper load securing and weight balancing
- Assuming all containers are identical - Specifications vary slightly between manufacturers and age of containers
Key Takeaways
- Standard dry containers (20', 40', 40'HC) handle 90% of general cargo
- Reefers are essential for temperature-sensitive goods but have 10-15% less volume
- Open tops allow crane loading for oversized height cargo
- Flat racks handle heavy machinery and out-of-gauge shipments
- Tank containers safely transport liquids using standard container infrastructure
- ISO codes tell you everything about a container at a glance
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