Portable Storage Containers

Basics of Portable Storage Containers

Portable storage containers are ISO (International Standards Organization) shipping containers that have been retired from use in international shipping lines and are available for rent and purchase on the domestic market.

NPSA members offer portable storage containers in standard lengths of 5 ft, 10 ft, 15 ft, 20 ft, 22 ft, 25 ft, 35 ft, 40 ft, 45 ft, and 53ft.

Every portable storage container or shipping container is made from cor-ten steel. Corten Steel |COR-TEN® is a type of weathering steel that resists corrosion and typically exhibits a 50 ksi minimum yield strength. Corten steel has become the standard for shipping containers, steel bridges, and buildings that are exposed to a marine environment. Since every shipping container is built to withstand the very harshest conditions on the open ocean and in the container yard, they easily protect your valuable items. Every storage container is secure, durable, and strong.

Portable storage containers are constructed with 12 and 14 gauge corrugated steel sides, steel framing, and 1 1/8'' thick marine plywood floors. Standard storage containers come with cargo doors on one end of the container. The cargo doors seal tight from rodents and inclement weather. They also allow you to access to the entire end of the container when fully open, making loading and unloading very large items a breeze!

Container Specifications

The majority of standard shipping containers are available in two lengths, 20ft and 40ft, and are 8ft 6 in high and 8 ft wide.

ISO shipping containers are manufactured to exact size specifications in order to ensure that all containers that machinery and vessels used in the shipping process will fit all shipping containers. Interior specification can have some slight variation (less than 1in.) but we can give you the exact exterior dimensions for your storage container. Take a look at the different specifications below.


Typical Dimensions


Exterior Interior Door Opening
  Length Width Height Length Width Height Width Height
10' Standard Dry Container 10' 8' 8'6" 9'3" 7'8" 7' 9 7/8" 7'8" 7'5"
20' Standard Dry Container 20' 8' 8'6" 19'3" 7'8" 7' 9 7/8" 7'8" 7'5"
40' Standard Dry Container 40' 8' 8'6" 39' 5" 7'8" 7' 9 7/8" 7'8" 7'5"
40' High Cube Dry Container 40' 8' 9'6" 39' 5" 7'8" 8' 10" 7'8" 8' 5 1/2"
45' High Cube Dry Container 45' 8' 9'8" 44' 5" 7'8" 8'10" 7'8" 8' 5 1/2"
20' Refrigerated Container 19' 10.5" 8' 8'6" 17' 11" 7'6" 7'6"* 7''5" 7'3"
40' Refrigerated Container 40' 8' 8'6" 37' 11" 7'6" 7'6"* 7''6" 7'6"
40' High Cube Refrigerated Container 40' 8' 9'6" 37' 11" 7'6" 8'4"* 7''6" 8'4"


Typical Weights / Capacity

  Cubic Capacity Tare Weight Max Gross Max Payload
20' Standard Dry Container 1,165 sq. ft. 5,050 67,200 62,150
40' Standard Dry Container 2,350 sq. ft. 8,000 67,200 59,200
40' High Cube Dry Container 2694 sq. ft. 8,775 67,200 58,425
45' High Cube Dry Container 3043 sq. ft. 9,810 72,800 62,990
20' Refrigerated Container 1,010 sq. ft. (967)** 6,503 52,800 46,407
40' Refrigerated Container 2,051 sq. ft. (1959)** 9,700 67,200 57,450
40' High Cube Refrigerated 2,380 sq. ft. (2,289)** 9,590 70,550 60,960


Container Conditions

Portable storage containers come in a variety of conditions. These conditions allow you to find the shipping container that best meets your storage needs and your budget.

NPSA members have portable storage containers and shipping containers available in new “One­Trip”, WWT, Cargo­worthy, and As ­Is conditions.


One Trip

One trip containers are the newest containers available on the market. Less than a year old, they make only one trip over from the factory in Asia before being sold to you. They are brand new from the factory with single color paint and no unattractive shipping line decals on the exterior. While they make have a ding or two from making the trip here, one-trip containers have a long life ahead of them. Every one-trip container is guaranteed to be cargo worthy and wind and watertight.



While every storage container was used to carry cargo at one or another, not every shipping container available for rent or purchase is automatically deemed to be cargo-worthy. In order to receive a portable storage container that is designated as cargo-worthy a container must be surveyed or certified by a licensed surveyor. The cargo-worthy inspection criteria is based on condition of the doors, floor, walls and ceiling as well as the container's structural integrity. Selecting a cargo worthy container that has been surveyed as cargo worthy ensures that you will receive a container that is in good condition, structurally sound, and able to be shipped if needed.


Wind and Watertight

A wind and watertight or WWT container is a used shipping container (retired from active shipping service after approx. 10 years) that is guaranteed to be wind and watertight. They are free from any holes or other damage that would allow weather to affect the contents of the container. WWT storage containers are available in a range of colors and conditions. They are randomly colored and often have some dents and surface rent left over from the shipping process. While not as aesthetically pleasing as other options, WWT shipping containers provide an ideal mix of economy and function.


As Is

As Is container is a used shipping container (retired from active shipping service after approx. 10 years) that is being sold without any specific industry standard.

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