Every year, billions of tonnes of goods travel across oceans, railways, and highways inside standardised steel boxes. These are intermodal containers, and they are the backbone of global trade.
Whether you are a logistics professional, a business owner planning shipments, or simply curious about how products move from factory to doorstep, this guide covers everything you need to know. And if you are looking to buy or lease containers in Singapore, Infinex has you covered with a full range of new and used intermodal containers.
What Is an Intermodal Container?
An intermodal container is a large, standardised steel box designed to transport cargo across multiple modes of transport, including ships, trains, and trucks, without unloading and reloading the goods inside. The word “intermodal” literally means “between modes.”
Their dimensions, construction, and handling features are governed by ISO standards (ISO 668, ISO 1496, and ISO 6346). This means a container built in China can be lifted by a crane in Rotterdam, loaded onto a truck in Singapore, and stacked on a railcar in the United States, all without modification.
The TEU Explained
The Twenty-foot Equivalent Unit (TEU) is the standard measurement for container capacity. One TEU equals one 20-foot container. A 40-foot container equals two TEU (also called 1 FEU, or Forty-foot Equivalent Unit). When a vessel is rated at 24,000 TEU, that is its capacity in 20-foot container equivalents.
Common Terminology
You will hear several terms used interchangeably: shipping container, ISO container, intermodal container, freight container, and conex box (a U.S. military term from the 1950s). They all refer to the same standardised steel box. At Infinex, we use “shipping container” and “intermodal container” depending on context, but the product is the same. Learn more on our about page.
A Brief History
The concept of containerised transport dates back to 1766, when James Brindley designed wooden containers for coal transport on England’s Bridgewater Canal. Railways adopted the idea in the 1830s, and the U.S. military developed the “Conex” system during the Korean War.
The real breakthrough came on 26 April 1956, when trucking entrepreneur Malcolm McLean shipped 58 containers aboard the Ideal X from Newark to Houston. His system cut cargo handling costs by roughly 95 percent, eliminating the labour-intensive break-bulk process where dock workers loaded goods by hand.
By 1968, the ISO published the first container standards, establishing the 20-foot and 40-foot lengths as the global norm. In 1972, the International Maritime Organisation adopted the Convention for Safe Containers (CSC), setting safety requirements still in force today.
Now, intermodal containers carry approximately 90 percent of the world’s non-bulk cargo. Container ship capacity has grown from a few hundred TEU in the 1960s to over 24,000 TEU on the largest vessels.
Types of Intermodal Containers
Intermodal containers come in many configurations. Here is a breakdown of the most common types. For help choosing the right one, browse the full Infinex product range.
Dry / General Purpose (GP) – The workhorse of global shipping. Fully enclosed corrugated steel with plywood flooring and double doors at one end. Available in 20-foot and 40-foot lengths for everything from electronics to clothing.
High Cube – Same footprint as standard containers but one foot taller (9 ft 6 in), providing roughly 13 percent more volume. Ideal for lightweight, bulky cargo. The 40-foot high cube is now the default on many routes.
Reefer (Refrigerated) – Insulated units with integrated refrigeration, maintaining temperatures from -35 to +30 degrees Celsius. Essential for meat, seafood, dairy, pharmaceuticals, and flowers.
Open Top – Features a removable tarpaulin or hard top panels for crane loading from above. Suited for heavy machinery, marble slabs, and oversized items.
Flat Rack – Strong steel floor with collapsible or fixed end walls, no side walls or roof. Built for oversized cargo like boats, generators, and construction equipment.
Tank Container (ISO Tank) – A cylindrical stainless steel tank within an ISO frame. Transports liquids and gases including chemicals, food-grade oils, and fuels, typically holding 21,000 to 40,000 litres.
Open Side – Full-height doors along one or both sides for unrestricted lateral access. Great for wide cargo like plywood sheets and glass panels.
Double Door (Tunnel) – Doors at both ends for loading from either side. Particularly useful for storage with first-in, first-out access.
Ventilated – Similar to dry containers but with passive or active ventilation for moisture-generating cargo like coffee beans, cocoa, and garlic.
Need a customised container solution? Infinex supplies ISO-compliant intermodal containers in Singapore and can modify units to your exact specifications.
Intermodal Container Dimensions
The following table covers the most common intermodal container sizes. Figures are approximate and may vary slightly between manufacturers. For a detailed breakdown, see our container sizes guide.
| Specification | 20ft Standard | 40ft Standard | 40ft High Cube | 45ft High Cube |
| External Length | 6.058 m (19 ft 10.5 in) | 12.192 m (40 ft) | 12.192 m (40 ft) | 13.716 m (45 ft) |
| External Width | 2.438 m (8 ft) | 2.438 m (8 ft) | 2.438 m (8 ft) | 2.438 m (8 ft) |
| External Height | 2.591 m (8 ft 6 in) | 2.591 m (8 ft 6 in) | 2.896 m (9 ft 6 in) | 2.896 m (9 ft 6 in) |
| Internal Length | 5.898 m (19 ft 4 in) | 12.032 m (39 ft 5.5 in) | 12.032 m (39 ft 5.5 in) | 13.556 m (44 ft 5.5 in) |
| Internal Width | 2.352 m (7 ft 8.5 in) | 2.352 m (7 ft 8.5 in) | 2.352 m (7 ft 8.5 in) | 2.352 m (7 ft 8.5 in) |
| Internal Height | 2.393 m (7 ft 10 in) | 2.393 m (7 ft 10 in) | 2.698 m (8 ft 10 in) | 2.698 m (8 ft 10 in) |
| Internal Volume | 33.2 m3 (1,172 ft3) | 67.7 m3 (2,390 ft3) | 76.3 m3 (2,694 ft3) | 86.1 m3 (3,040 ft3) |
| Max Gross Weight | 30,480 kg (67,197 lb) | 30,480 kg (67,197 lb) | 30,480 kg (67,197 lb) | 30,480 kg (67,197 lb) |
| Tare Weight | 2,200 kg (4,850 lb) | 3,750 kg (8,268 lb) | 3,940 kg (8,687 lb) | 4,800 kg (10,582 lb) |
| Max Payload | 28,280 kg (62,347 lb) | 26,730 kg (58,929 lb) | 26,540 kg (58,510 lb) | 25,680 kg (56,615 lb) |
| TEU Equivalent | 1 TEU | 2 TEU (1 FEU) | 2 TEU (1 FEU) | 2.25 TEU |
How Intermodal Transport Works
Intermodal transport moves cargo in the same container across two or more transport modes without handling the freight itself. Here is how a typical journey unfolds:
- Loading at origin – Goods are packed into the container at a factory or warehouse, then sealed with a tamper-evident security seal.
- Drayage to port or rail terminal – A truck carries the container a short distance (typically under 100 km) to the nearest port or intermodal terminal.
- Terminal handling – Cranes lift the container off the truck chassis and place it onto a vessel or rail wagon using standardised corner castings.
- Long-haul transport – The container travels its longest leg by sea or rail. Ocean voyages can last weeks; rail covers major overland corridors.
- Transfer between modes – At an intermediate terminal, the container moves from ship to rail, rail to truck, or ship to truck, all without opening the box.
- Final delivery – A truck carries the container from the destination terminal to the consignee’s facility for unloading.
Intermodal vs Multimodal
These terms are often confused. Intermodal transport uses multiple carriers with separate contracts for each leg. Multimodal transport uses a single carrier responsible for the entire journey under one contract. In both cases, the cargo stays inside the same container throughout.
Benefits of Intermodal Containers
- Cost savings of 10 to 40 percent – Combining sea and rail for long-haul legs costs significantly less than trucking alone. A single freight train carries the equivalent of 280 trucks.
- Lower carbon footprint – Rail produces roughly 75 percent fewer emissions per tonne-kilometre than road transport, removing hundreds of truck journeys per train.
- Enhanced cargo security – Once sealed, the container stays closed until final destination. GPS tracking, electronic seals, and IoT sensors add real-time monitoring.
- Faster handling – Mechanised equipment loads and unloads containers in minutes, compared to hours or days for break-bulk cargo.
- Easy scalability – A small business ships one 20-foot container; a retailer fills thousands. The same infrastructure handles both.
- Supply chain resilience – Cargo can be rerouted between ports or shifted from sea to rail without repackaging. The container doubles as weatherproof mobile storage.
Industries That Rely on Intermodal Containers
- Maritime trade and global shipping – The largest user by volume, connecting Asia, Europe, and the Americas through major routes, with Singapore as a key transhipment hub.
- Retail and e-commerce – The vast majority of consumer goods travel inside containers at some point, from fast fashion to electronics.
- Agriculture and food – Grains, coffee, fresh produce, meat, and seafood move worldwide in dry and reefer containers.
- Automotive – Car manufacturers ship vehicles, parts, and engines between global assembly plants using flat racks and standard containers.
- Construction – Steel beams, pipes, tiles, and prefabricated components ship in standard and customised container configurations.
- Pharmaceuticals – Temperature-sensitive medicines and vaccines require reefer containers with precise climate control.
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Beyond Shipping: Other Uses
The durability and modularity of shipping containers have inspired creative applications. Infinex offers accessories and modification services for non-standard projects.
- Container architecture – Homes, offices, schools, restaurants, and hotels built from modified containers.
- Portable data centres – Pre-fitted with servers, cooling, and power distribution for rapid deployment.
- Disaster relief – Emergency shelters, medical clinics, and supply storage in hard-to-reach areas.
- Vertical farming – Self-contained hydroponic farms with LED lighting and climate control.
- Pop-up retail – Shops, cafes, and event spaces with a distinctive look and easy relocation.
Key Industry Statistics
- 30 million+ containers in active circulation worldwide, with 5 to 6 million in transit at any given time.
- 90 percent of non-bulk cargo moves in intermodal containers globally.
- 90 percent of containers are manufactured in China (led by CIMC, DFIC, and CXIC).
- 24,000+ TEU capacity on the largest modern container vessels.
- 10 to 15 year average lifespan in active maritime service, with structural life exceeding 25 years. After retirement from shipping, many are sold for storage or conversion. Browse used containers at Infinex for cost-effective options.
- Under 1 percent cargo damage rate, compared to 10 to 17 percent with traditional break-bulk methods.
Frequently Asked Questions
What is the difference between an intermodal container and a shipping container?
There is no practical difference. Both terms refer to the same standardised steel box. “Shipping container” is the everyday term, while “intermodal container” emphasises the ability to move between ships, trains, and trucks.
What sizes do intermodal containers come in?
The most common sizes are 20 feet and 40 feet long, both 8 feet wide. Standard height is 8 ft 6 in; high cube versions stand 9 ft 6 in. Less common sizes include 10-foot, 45-foot, and 53-foot containers.
How much does an intermodal container cost?
A new 20-foot container typically costs USD 2,500 to 5,000; a new 40-foot high cube ranges from USD 4,000 to 8,000. Used containers in good condition cost 30 to 60 percent less. Check the Infinex inventory for current pricing.
How long does an intermodal container last?
Typically 10 to 15 years in active shipping, but the steel structure can exceed 25 years. Many containers serve additional decades as storage or building modules after retiring from maritime service.
Can intermodal containers be stacked?
Yes. They are designed to stack up to nine high when fully loaded. On ships, containers are stacked 8 to 12 tiers above deck. In yards, stacking is usually limited to 4 to 6 high for safety.
Are intermodal containers waterproof?
Standard containers are wind-tight and watertight when in good condition. They undergo water-tightness testing during manufacturing. Older or damaged units may develop leaks around seals or corroded areas, so always inspect before loading moisture-sensitive cargo.
What is the CSC plate on a container?
The CSC (Convention for Safe Containers) Safety Approval Plate is a metal plate on every container used in international transport. It shows the approval number, manufacture date, maximum stacking weight, and inspection dates, confirming the container meets international safety standards.
Can I buy a used intermodal container?
Absolutely. Used containers offer excellent value for storage, conversion projects, and continued shipping. They are graded from “cargo worthy” to “as is.” Whether you need a standard dry container or a specialised unit, Infinex maintains a large stock of inspected used containers in Singapore.
Conclusion
The intermodal container is one of the most transformative inventions in modern trade. By standardising how goods are packed and transferred between ships, trains, and trucks, it has made global commerce faster, cheaper, and safer.
Ready to find the right container? Browse our full range of new and used containers, explore customised solutions, or contact us for expert advice. Infinex is Singapore’s trusted partner for all your container needs.