Container grades and condition
wind and water tight (WWT)
Wind and water tight is a trade term for a used container that should have no holes or defects that let wind or water in. It is not certified by an outside body. The seller decides whether a unit meets it, so definitions vary by company.
Why it matters
WWT is the common grade for on-site storage. These containers are generally older and show rust, dings and dents, and they usually cost less than cargo worthy units. Sellers typically inspect and repair them before resale, but no governing body inspects them. A WWT box may not suit overseas shipping. A common mistake is to assume WWT means no leaks ever. Doors, gaskets and roofs wear, so ask how the seller checks the unit, and what happens if it leaks after delivery. Operators can reduce disputes by writing their WWT test, such as a light leak test and a door check, on the sales or rental paperwork.
Read: Shipping container grades explained: One-trip, IICL, cargo worthy, and WWT
Definition source: eagleleasing.com
Related terms
cargo worthy (CW)
Cargo worthy is a trade term for a used container that is sound enough to carry cargo by sea. It points to structural condition, not looks. Sellers define it slightly differently. It does not by itself prove the container holds a current CSC plate or survey.
light leak test
A light leak test is a simple check for holes in a container. A person steps inside, closes the doors and looks for light coming through the walls, roof, floor or door seals. Light usually means water can get in too.
used container
A used container is a container that has served a working life, usually at sea, before being sold or rented for storage. Sellers grade used units, often as cargo worthy, wind and water tight or as-is. The grade affects price, appearance and how well the unit keeps out water.
one-trip container
A one-trip container is a container that has made a single cargo voyage from the factory before being sold or rented. It is close to new. It usually has clean lines, solid floors and doors that work smoothly. Sellers use the term in slightly different ways.
container inspection
A container inspection is a check of a container's outside, inside, doors, floor and roof for damage, leaks and wear. Buyers do it before purchase. Operators do it when units go out and come back. It can be a quick look or a formal review to a standard.
storage container
A storage container is a container used to store goods, often a retired shipping container, that sits on a site and keeps items dry and secure. Companies rent or sell them in several sizes and conditions. Many have double doors on one end and can be lifted or moved on a truck.
For the industry
Grow your portable storage business with NPSA
Members get event rates, the Community Forum, the directory listing and leads from this website.
Need storage?
Get quotes from NPSA member companies
Tell us what you need and where. A member company that serves your area will contact you.