When you shop for a used container you will see terms like “one-trip”, “cargo-worthy” and “wind and watertight”. These shipping container grades describe the condition of the container and what it is fit for. Understanding them helps you compare prices fairly and avoid paying for a better grade than you need, or buying one that is not good enough.
Container condition grades at a glance
| Grade | Condition | Best for |
|---|---|---|
| New / one-trip | Near new, minimal marks | Conversions, visible locations, long-term use |
| Cargo-worthy (CW) | Used, structurally sound, certified for shipping | Exporting goods, heavy-duty storage |
| Wind and watertight (WWT) | Used, weatherproof, cosmetic wear | Storage on sites, farms and at home |
| As-is / damaged | May leak or have structural damage | Parts, projects, very low budgets |
New and one-trip containers
A one-trip container is built, usually in Asia, and shipped to the UK once with cargo inside. It arrives in near-new condition with clean paintwork, sound seals and a good floor. It is the closest thing to a brand new container and the best choice for conversions, painted finishes and locations where appearance matters.
Cargo-worthy (CW) containers
A cargo-worthy container has been inspected and is structurally fit to carry goods at sea. It must have a valid CSC (Convention for Safe Containers) plate. Cargo-worthy containers are used but strong, with a sound frame, floor, roof and doors. You need this grade if you intend to ship goods overseas.
Wind and watertight (WWT) containers
Wind and watertight means the container keeps out wind and rain: no holes, working doors and seals. It will usually show dents, surface rust and patched paintwork from years at sea. For most storage uses, a WWT container is excellent value. It may not be certified for shipping.
As-is containers
As-is containers are sold without any guarantee of condition. They may leak or have damaged floors or doors. They can suit a project where you plan to repair or cut the container, but they are not a good choice for storing anything valuable.
Refurbished containers
Some used containers are refurbished before sale: rust is treated, damaged panels are repaired and the container is repainted. A refurbished container gives you a smarter finish than a standard used unit at a lower price than a one-trip.
What to check when buying a used container
- Doors: they should open, close and lock smoothly, with rubber seals in good condition.
- Roof: look for holes, deep dents or areas where water could pool.
- Floor: the marine plywood floor should be solid, without soft or rotten patches.
- Light test: close the doors from inside. If you can see daylight, there is a hole.
- Rust: surface rust is normal, but rust that has eaten through the steel is not.
- Smell: strong chemical smells can indicate what was carried before.
Which grade should you buy?
- For general storage, a wind and watertight container gives the best value.
- For export or shipping, buy a cargo-worthy container with a valid CSC plate.
- For a conversion or a container that will be on show, choose one-trip.
Compare the price difference in our new vs used pricing guide, or read more in new vs used shipping containers.
Shipping container grades: what to ask before you buy
Whatever shipping container grades a seller uses, ask for the grade in writing and look at recent photos of the roof, floor, door seals and corner posts. Terms such as “cargo-worthy” and “wind and watertight” are not identical, so check what each one means for the container you are buying. Organisations such as the British Standards Institution (BSI) publish standards used across industry, but for a shipping container purchase the most useful check is still an inspection or clear photographs.
If you cannot visit, ask the supplier to describe any dents, patches or rust and to confirm that the doors open and lock properly. Matching the grade to the job, for example a higher grade for a site office and a lower grade for rough storage, helps you avoid paying for more than you need.
Frequently asked questions
What does a CSC plate mean?
A CSC plate shows a container has been approved as safe for international transport under the Convention for Safe Containers. You need one to ship goods, but not for static storage.
Will a used container leak?
A container sold as wind and watertight should not leak. Always check the roof, doors and seals, and ask the seller what the grade covers.
How long does a used container last?
With basic maintenance, a used container can last many years as storage. See our maintenance guide for simple ways to extend its life.
Browse containers by grade
Browse our shipping containers for sale, including one-trip, cargo-worthy and wind and watertight units, or request a quote and we will help you pick the right grade.
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