Container Types: Dry, Reefer, Open Top & Flat Rack

Picking the right box decides what fits, how it loads and what you pay. This page walks through the main ISO container types you will meet on European and intercontinental lanes, the standard sizes, and the trade-offs that should drive your choice.

The main container types

Type	Best for	Notes
Dry van (standard)	General palletised and boxed cargo	The default box; weatherproof steel, doors at one end
High cube (HC)	Light, voluminous cargo	Same footprint as a dry van but ~30 cm taller inside
Reefer	Temperature-controlled goods	Insulated, powered unit holds a set temperature
Open top	Over-height or crane-loaded cargo	No solid roof; tarpaulin cover instead
Flat rack	Oversized, heavy or awkward loads	Collapsible ends, no walls or roof
Tank (ISO tank)	Liquids, gases, chemicals	Cylindrical vessel in a frame
Ventilated	Cargo that needs airflow	Vents along the rails; common for coffee, cocoa

A dry van covers most freight: pallets, cartons, sacks and machinery that fit through the rear doors. Choose a high cube when your cargo is light but tall — you gain volume without paying for a second box. A reefer is the only option when goods must stay chilled or frozen; see the reefer container glossary entry for setpoint and power detail.

Reach for an open top when the cargo is taller than the door aperture or must be lifted in by crane — think glass, timber stacks or tall machinery. A flat rack handles loads too wide or too heavy for any enclosed box, such as vehicles, pipes or industrial plant. Tank and ventilated containers are specialist: tanks move bulk liquids and gases under their own safety rules, while ventilated boxes let agricultural cargo breathe in transit.

Standard sizes

Containers come in a small set of standard lengths and heights. These four cover the vast majority of moves:

Size	External length	External height	Typical use
20 ft	6.06 m	2.59 m	Dense, heavy cargo where you hit the weight limit first
40 ft	12.19 m	2.59 m	Standard high-volume cargo
40 ft HC	12.19 m	2.90 m	Voluminous, lighter cargo needing extra height
45 ft HC	13.72 m	2.90 m	Maximum reach for palletised volume

A 20 ft box often fills on weight before it fills on space, while a 40 ft fills on volume first — so dense goods favour the 20 ft and bulky goods the 40 ft or HC. For exact internal dimensions, door openings and payloads, see the full container dimensions reference, and run your load through the CBM calculator before you commit.

How to choose

Work from the cargo, not the box. Ask:

• Does it need temperature control? Reefer, no exceptions.
• Is it taller than the door or needs crane access? Open top.
• Is it over-width, over-length or very heavy? Flat rack.
• Is it bulk liquid or gas? ISO tank, with the right hazmat handling.
• Is it ordinary boxed or palletised freight? Dry van — high cube if it is light and tall.

If your shipment moves by sea and road across legs, plan it as one intermodal transport flow so the same box runs door to door. Once you know the type and size, UMERA turns those requirements into booked carrier quotes through a single RFQ, instead of emailing forwarders one at a time. For the road leg specifically, our guide to European road freight covers how containerised loads connect to trailer capacity.

FAQ

What is the difference between a dry van and a high cube container?

Both share the same length and footprint, but a high cube is about 30 cm taller inside (2.90 m external vs 2.59 m). Choose a high cube when cargo is light and bulky so you pay for volume, not extra weight you do not have.

When should I use a flat rack instead of an open top?

Use an open top when cargo is over-height but still fits the floor width and needs crane loading. Use a flat rack when the load is over-width, over-length or too heavy for an enclosed box — its collapsible ends and open sides take loads no walls would allow.

Which container size is most economical?

It depends on density. Heavy, compact cargo usually costs less in a 20 ft because you reach the weight limit before running out of space; bulky, lighter cargo is cheaper per unit in a 40 ft or 40 ft HC where volume is the limiting factor.

Do I need a reefer for ambient goods?

No. A reefer is for goods with a temperature setpoint. Ambient cargo that only needs airflow — coffee, cocoa, some produce — travels better and cheaper in a ventilated container.