Container Condition
Container grade is the most honest data point on a used container. It tells you what’s been inspected, against which standard, and what kind of cargo or end-use the container can be put to. Here are the six grades operators actually trade against, what each one guarantees, and what doesn’t get covered.
Why grade matters
A 20ʹ container is a 20ʹ container — the dimensions don’t change with age. What changes is the structural condition: floor integrity, gasket seal, corner casting wear, paint and rust state, door hardware, and whether the CSC safety plate is current. Grade is industry shorthand for which of those things has been inspected, and what the inspector found.
NPSA portable-storage operators reselling to end-customers care about grade for two reasons. First, it’s the basis of the quote: a CW container costs less than a 3-Trip, which costs less than NEW. Second, it’s the basis of the warranty: you can’t sell a WWT container as "ocean-cargo ready" because it isn’t, and an end-customer chasing that claim has a real complaint.
The grade hierarchy
From newest to oldest, with the typical depot-pricing relationship. Grades aren’t ISO or government regulated — they’re an industry consensus that’s been stable since the 1980s. The two with formal inspection backing are IICL (defined by the Institute of International Container Lessors) and CW (which references the CSC Safety Convention).
| Grade | What it is | Ocean cargo? |
|---|---|---|
| NEW / 1-TRIP | Brand new, used for one outbound voyage from factory | Yes — current CSC |
| 3-TRIP | Light use, 3–5 voyages, lessor-refurbished | Yes — current CSC |
| IICL | Passes the Institute of International Container Lessors inspection | Yes — current CSC |
| CW | Cargo Worthy — passes CSC inspection, structurally sound | Yes — current CSC |
| WWT | Wind & Water Tight — seals out weather but not CSC-certified | No |
| AS-IS | Sold without inspection or warranty | No |
The grades in detail
Brand new from the factory
~5 years on the CSC plateBuilt in the last 6–18 months, used for one outbound voyage (typically Asia to North America) carrying its first cargo load. Sold immediately at the destination depot before entering any lessor’s pool.
What you get: pristine paint inside and out, original gaskets seated correctly, the original plywood or bamboo floor unworn, all corner castings square, doors that close with thumb pressure. One ocean crossing means the occasional minor transit ding is possible — rare, and cosmetic only. CSC safety plate is fresh and runs the full five years before re-inspection is required.
The "1-trip" qualifier matters because true zero-trip (never used) containers are rare in the US — almost everything sold as NEW has crossed an ocean once. This isn’t a deception; it’s the industry’s working definition of new and the highest you can practically buy.
Use it for: customer-facing inventory where appearance matters (rental-to-own, residential storage, modification projects), or any cargo that requires guaranteed no-contamination interior history.
Light use, lessor-refurbished
~3 years on the CSC plateThree to five voyages of light service, then surveyed and refurbished by a lessor before resale. Structurally identical to NEW — same panel thickness, same door hardware, same corner castings. Cosmetically wears a few honest dings.
What changes vs. NEW: minor surface scratches and the occasional small dent on external panels. The interior is typically still very good — three voyages with palletized cargo doesn’t beat up plywood much. Lessor-refurbished means the doors have been re-greased, gaskets checked, paint touched up, and any small rust spots treated. CSC plate is current.
Use it for: cost-conscious customer-facing inventory, premium ground storage, or modification projects where the build will hide the cosmetic wear anyway.
Institute of International Container Lessors
Strictest commercial inspectionIICL maintains the strictest commercial inspection criteria in the industry — more restrictive than the CSC pass criteria. An IICL-passing container has met thresholds on dozens of damage and wear measurements: dent depth, paint coverage, rust progression, door hardware tolerances, floor integrity, corner casting wear.
The standard is published as a series of editions (IICL-5, IICL-6, current is IICL-7). When a lessor sells "IICL containers" they mean inventory that’s been inspected against and passes the current IICL bar. Major leasing fleets (Triton, Textainer, Beacon) routinely sell off IICL inventory when they’re retiring containers from the leased pool.
What you get: a container that’s been through commercial-grade inspection more recently than typical CW inventory. Better-than-average condition. CSC plate current.
Use it for: customers who need documentation of recent inspection (some industrial and government contracts specify "IICL or better"), or as a premium tier between CW and 3-Trip when budget doesn’t stretch to 3-Trip.
Cargo Worthy
CSC-passing · cleared for international ocean cargoThe workhorse grade. A CW container has passed inspection against the Convention for Safe Containers (CSC) — meaning it’s structurally sound enough to carry international ocean cargo. CSC plate is current (re-inspection due date in the future, not the past).
What CW allows: dents up to specified depths, repaired panels and patches, paint wear, surface rust (not through-rust), some pitting, missing logos and paint variations. The container has clearly been used and shows it.
What CW does NOT allow: holes, through-rust, structural cracks, broken corner castings, door hardware that doesn’t operate, missing or expired CSC plate, water ingress, soft floor.
"Watertight" is the practical test: with the doors closed, no light is visible from the inside. If you can see daylight, it’s not CW — it’s WWT or lower.
Use it for: standard wholesale resale, ground storage, container modification projects where the buyer needs the container to be structurally sound but doesn’t care about cosmetics, one-way leasing for return-of-cargo loads.
Wind & Water Tight
Holds out weather · no longer CSC-ratedA WWT container holds out wind and water — doors close, gaskets seal, the roof doesn’t leak — but does not (or no longer) passes CSC inspection. The CSC plate is either expired or the container has accumulated damage that would fail re-inspection. Not eligible for ocean cargo. Still useful for any application that keeps the box on the ground.
What you can expect on a WWT: more visible dents, paint failure, surface rust patches, occasional patched repair plates. Floor may be aged but intact. Doors may require some effort to seal. The watertight test still passes — no light from inside.
Use it for: ground storage (the largest single market), container homes and modifications, agricultural use, construction-site storage, equipment shelters, shipping-container offices and workshops. Anything that won’t be lifted onto a ship.
No inspection, no warranty
Project containers · buyer assumes all riskSold without inspection, without warranty, and usually without a current CSC plate. May have holes, through-rust, missing corner castings, broken door hardware, soft floor, or any combination. Sometimes also referred to as "project containers" or "scrap-grade."
What you should expect: anything. A specific AS-IS container might be 95% sound with one fixable patch needed, or it might be unsalvageable. Walk it before you buy.
Use it for: scrap metal recovery, art and sculpture projects, custom modification where the buyer is going to gut the structure anyway, single-trip on-site use where the box doesn’t need to move again.
What gets inspected — the visual checklist
When a container is graded, the inspector walks the box looking for specific failure modes. For NPSA operators receiving inventory at the depot, the same checklist applies to incoming acceptance. Take it in order — top to bottom, then outside, then inside.
- Roof. Walk the perimeter, look for ponding, dented panels, and patch repairs. Hairline cracks or pitting near the roof bows are the most common WWT disqualifier.
- Corner castings. All eight should be present, square, and unworn. Crane and lift-truck damage tends to round off the casting openings — once a casting is mushroomed, the container can’t be safely lifted with twist-locks.
- Doors. Open and close both doors. Cam lock rods should engage cleanly with thumb pressure, gaskets should be present and pliable (not torn or hardened), and the doors should seal flush against each other. Test with the watertight check.
- CSC Safety Approval Plate. Required for ocean cargo. The plate lists the manufacturer, build date, max gross weight, and the date of next inspection. If that date is in the past or the plate is missing, it’s not CW or above.
- Side panels. Sight along the length looking for dent depth and through-rust. Surface rust (orange-brown) is fine; black or scaly rust suggests through-rust underneath.
- Floor. Walk the interior. Soft spots, water staining, and visible patch repairs are condition flags. Original plywood is approximately 28mm thick; replacement bamboo or steel patches indicate prior damage.
- Watertight check. Close the doors, stand inside, look around. Visible daylight means it’s not watertight — automatically below CW.
- Owner markings. The BIC prefix, container number, and check digit should all be legible. See the ISO 6346 guide for what’s expected, and the BIC Codes guide for what the prefix tells you.
A CSC plate showing a re-inspection date one month in the future is current; a plate showing a date one month in the past is not. There’s no grace period under the CSC convention itself, though some jurisdictions allow up to 30 days. For your records, assume zero grace — an expired CSC means re-inspection is required before the container can carry ocean cargo again, and the cost of that inspection should be factored into any used-CW deal.
Matching grade to use case
Practical guidance for operators specifying inventory:
- Customer-facing rental fleet: NEW or 3-Trip. End-customers see the container and judge it on appearance.
- Long-term ground storage at a customer site: CW or IICL. Watertight is non-negotiable, but cosmetics matter less.
- Container modification (homes, offices, workshops): WWT minimum. The modification will replace gaskets, repaint, and patch panels anyway — pay for structural soundness, not cosmetics.
- One-way leasing for export cargo: CW or better. CSC plate must be current.
- Scrap / art / project use: AS-IS. Walk the box first.