The Container
Reference.
Everything technical about steel shipping containers in plain English — real dimensions, how to read the markings, and what a used Wind & Water Tight box actually is.
Container Dimensions & Specifications
Standard sizes per ISO 668:2020. We sell the three marked “We sell” as Wind & Water Tight (used); the rest are here for reference.
| Size | External (L×W×H) | Interior L | Interior W | Interior H | Door (W×H) | Capacity | SBD |
|---|---|---|---|---|---|---|---|
| 10ft Standard | 9'9.75" × 8'0" × 8'6" | 9'3" | 7'8.5" | 7'10.1" | 7'8.1" × 7'5.8" | 561 cu ft | Reference |
| 20ft Standard | 19'10.5" × 8'0" × 8'6" | 19'4.2" | 7'8.5" | 7'10.1" | 7'8.1" × 7'5.8" | 1,172 cu ft | ✓ We sell → |
| 20ft High Cube | 19'10.5" × 8'0" × 9'6" | 19'4.2" | 7'8.5" | 8'10.1" | 7'8.1" × 8'5.8" | 1,320 cu ft | Reference |
| 40ft Standard | 40'0" × 8'0" × 8'6" | 39'5.7" | 7'8.5" | 7'10.1" | 7'8.1" × 7'5.8" | 2,387 cu ft | ✓ We sell → |
| 40ft High Cube | 40'0" × 8'0" × 9'6" | 39'5.7" | 7'8.5" | 8'10.1" | 7'8.1" × 8'5.8" | 2,691 cu ft | ✓ We sell → |
| 45ft High Cube | 45'0" × 8'0" × 9'6" | 44'5.7" | 7'8.5" | 8'10.1" | 7'8.1" × 8'5.8" | 3,037 cu ft | Reference |
- 10ft Standard: Typically one-trip/new only; rarely available used.
- 20ft High Cube: Uncommon in the used market; usually one-trip/new.
- 40ft High Cube: In 40ft, the High Cube is more common than the standard height.
- 45ft High Cube: High-cube only; usually needs an oversize permit or extendable trailer to move.
Comparing footprints? See the complete 10ft–45ft size chart.
How to Read a Container’s Markings
Every container is stamped with a standardized identity under ISO 6346. Here’s what the letters and numbers mean.
The 11-character ID number
| Part | What it means |
|---|---|
| Owner Code (3 letters) | The registered owner/operator prefix, issued through BIC (bic-code.org). |
| Equipment Category (1 letter) | U = freight container · J = detachable freight-container equipment · Z = trailer or chassis. |
| Serial Number (6 digits) | The individual unit's number, assigned by the owner. |
| Check Digit (1 boxed digit) | A math-derived digit (shown in a box) that validates the other 10 characters. |
The 4-character size & type code
1st char — length
- 1 10ft
- 2 20ft
- 3 30ft
- 4 40ft
- L 45ft
2nd char — height / width
- 0 8'0" high
- 2 8'6" high (standard)
- 4 4'3" high (half-height)
- 5 9'6" high (high cube)
- C 8'6" high & over 8' wide
3rd–4th chars — type
- G0 / G1 General-purpose dry van (G1 = passive-vented)
- V0 / V2 Mechanically ventilated
- U0 / U1 Open-top
- P1 / P3 Flat rack / platform
The CSC Safety Approval Plate
Required under the IMO International Convention for Safe Containers, the CSC plate is the container’s “passport” — it records structural approval and inspection history and stays with the unit into the used market.
Want to decode the rest of the stampings? Here’s how to read the full ID number and run the check digit yourself.
Lifecycle: Why a Used Box Is a Smart Buy
A Wind & Water Tight container is retired from the sea, not worn out. Here’s why used steel holds up.
Built from weathering steel
Shipping containers are made from Cor-Ten (weathering) steel, which forms a stable, non-porous patina as it ages. That's why the surface rust you see on a used box is usually cosmetic, not structural — the steel is protecting itself.
Decades of service life
A container spends roughly 10–12 years in active maritime service, then can last 25+ years in static land use with basic maintenance. A Wind & Water Tight unit is retired from the sea, not worn out.
Why used units are abundant
North America imports far more containerized freight than it exports, and repositioning empty boxes back overseas costs more than building new ones. So shipping lines sell them off here — which is why a sound used container is widely available and a smart-value buy.
See exactly what we sell → our condition guide.
Reference FAQ
What do the numbers on a shipping container mean?
Every container carries an 11-character ID under ISO 6346: a 3-letter owner code registered with BIC, a 1-letter equipment category (U for freight containers), a 6-digit serial number, and a boxed check digit that validates the rest.
How do I read a container's size and type code?
The 4-character size/type code sits below the ID. The first character is length (2 = 20ft, 4 = 40ft, L = 45ft), the second is height/width (2 = 8'6" standard, 5 = 9'6" high cube), and the last two describe the type (G1 = general-purpose dry van).
What is the CSC plate on a shipping container?
The CSC Safety Approval Plate, required under the IMO International Convention for Safe Containers, is the container's passport — it records structural approval and inspection history and stays with the unit into the used market.
Is surface rust on a used container a problem?
Usually not. Containers are built from Cor-Ten weathering steel that forms a protective patina, so surface rust is typically cosmetic. Every container we sell is Wind & Water Tight — structurally sound and sealed against rain, wind, snow, and pests.
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