What are the main ocean container types?

Standard dry containers (20ft and 40ft, plus 40ft and 45ft high-cube variants) carry the majority of general cargo, while specialized equipment — reefer (refrigerated), open-top, and flat-rack containers — handles temperature-sensitive, oversized, or irregularly shaped cargo. Independent dispatch data indicates that reefer containers represent a disproportionately small share of total inbound volume at West Coast ports relative to dry containers, but require dedicated plug-in monitoring at the terminal and are prioritized for faster discharge to limit power-off time.

Container Types Explained: Dry, Reefer, Open-Top, and Flat-Rack

Cost structure / standard tiers

Specialized equipment carries both higher base freight rates and additional handling fees compared to standard dry containers.

Container Type	Typical Capacity	Freight Rate Premium vs. Standard Dry
20ft/40ft standard dry	20ft: ~28 CBM / 40ft: ~58 CBM	Baseline
40ft/45ft high-cube dry	~68-76 CBM	+0-5% (often same rate)
Reefer (20ft/40ft)	Similar to dry, temp-controlled	+50-100% over dry equivalent
Open-top	Same footprint, removable roof	+15-30%, plus crane/lift fees for top-loading
Flat-rack	Platform only, no walls/roof	+20-40%, plus lashing/securing and OOG fees ($100-300)

Reefer containers also carry ongoing genset rental or plug-in fees ($50-150/day) when not connected to terminal power.

Risk mitigation / operational guidance

Confirm container type availability with the carrier at booking, especially for reefer and flat-rack equipment, since specialized units are allocated from a smaller pool and can cause booking delays during peak season. For reefer cargo, verify the terminal has confirmed plug-in availability before vessel arrival — reefer containers awaiting power connection accrue both demurrage exposure and cargo condition risk. For open-top and flat-rack cargo, arrange specialized lifting equipment at the destination drayage point in advance, since standard chassis and forklifts may not handle top-loaded or rack-mounted cargo. When high-cube containers are available at no rate premium, request them by default for volume-constrained (not weight-constrained) cargo to maximize utilization per container.