Short definitions of the terms you come across when buying or leasing a container, or when asking for an inspection or repair quote. Each definition is written to be read on its own; for more detail we link to the related guides and free tools.
Standards and organisations
CSC (Convention for Safe Containers)
The International Convention for Safe Containers, adopted by the International Maritime Organization (IMO) in 1972. It requires containers used in international transport to be built to an approved design, to carry a safety approval plate and to be examined regularly.
CSC plate
The safety approval plate headed “CSC SAFETY APPROVAL”, fixed permanently to the container door. It shows the approval reference, date of manufacture, maximum gross mass, and stacking and racking test values; the examination status appears on or next to the plate. More: CSC plate guide.
PES (Periodic Examination Scheme)
One of the two examination methods accepted by the CSC. The first examination takes place within 5 years of manufacture and subsequent ones at most every 30 months; the next examination date is marked on the plate.
ACEP (Approved Continuous Examination Programme)
A continuous examination programme that the container owner has had approved by the administration. The container is examined regularly at on-hire/off-hire interchanges and during repairs, with no more than 30 months between examinations. The plate carries an ACEP number instead of a date. More: ACEP guide.
IICL
The Institute of International Container Lessors — the association of international container leasing companies. Its inspection and repair manuals are the industry-accepted criteria for assessing and repairing damage on leased containers.
ISO 6346
The international standard that defines the coding, identification and marking of containers. It sets out the structure of the container number, how the check digit is calculated, and the size-type codes. More: container number guide.
BIC
The Bureau International des Containers, based in Paris. It registers owner codes — the first three letters of a container number; the same code is never issued to two companies.
The container number
Container number
An 11-character identifier defined by ISO 6346: a 3-letter owner code, a 1-letter equipment category, a 6-digit serial number and a 1-digit check digit. Example: CSQU 305438 3.
Owner code
The first three letters of the container number. It identifies the owner or operator of the container and is registered by BIC.
Equipment category
The fourth letter of the container number: U means a freight container, J detachable container-related equipment, and Z trailers and chassis.
Check digit
The last digit of the container number. It is calculated from the first ten characters with a mod 11 algorithm and serves to catch typing errors. It can be verified in seconds with the check digit calculator.
Size-type code
A four-character code shown below or beside the container number. The first character gives the length, the second the height and the last two the type: 22G1 is a standard 20 ft dry container, 45G1 a 40 ft high cube dry container.
Container types
Dry (general purpose) container
The most common closed container type, used for dry cargo. It comes in 20-foot and 40-foot lengths; the standard external height is 2.591 m.
High Cube (HC) container
A type that is 30.5 cm taller than a standard container: the external height is 2.896 m instead of 2.591 m. The footprint is the same; the extra height helps with bulky cargo.
Open Top container
A type closed with a removable tarpaulin and roof bows instead of a fixed roof. Cargo is loaded from above by crane.
Flat Rack container
A platform type without side walls or a roof. Out-of-gauge and heavy project cargo is loaded from the side or from above.
Reefer (refrigerated) container
An insulated, temperature-controlled container with an integrated refrigeration unit at the front end. Maintenance points: reefer maintenance guide.
For the external and internal dimensions, volume and tare of each type, see the dimension table in the 3D container viewer.
Size and weight
Tare
The empty weight of the container. Typically about 2,230 kg for a standard 20-foot container and about 3,740 kg for a 40-foot one; it varies by manufacturer.
Maximum gross mass
The highest mass the container may reach together with its cargo (Maximum Operating Gross Mass). It is shown on the CSC plate in kg and lbs.
Payload
What remains when the tare is subtracted from the maximum gross mass: the greatest weight of cargo that can be loaded into the container.
TEU
Twenty-foot Equivalent Unit. One 20-foot container counts as 1 TEU and one 40-foot container as 2 TEU; ship and port capacities are expressed in this unit.
Allowable stacking mass
The total load that may be stacked on top of the container (for 1.8 g). It is stated on the CSC plate.
Racking test value
The test value showing the force the container’s side walls must withstand as a ship rolls. It is stated on the CSC plate.
Inspection and repair
Survey (inspection)
The on-site examination and reporting of a container’s condition by a specialist. Depending on the purpose it takes the form of a CSC or ACEP examination, or a damage, condition, after-repair or lashing survey. More: container inspection.
Damage survey
A report documenting, with photographs, the location, extent and cause of the damage found.
Condition survey
A full photographic record of a container’s structural and cosmetic condition. It is used before a sale or lease.
After-repair survey
A report independently confirming that a repair meets IICL standards. For leased containers and those changing hands, it lets the other party accept the container with confidence.
On-hire / off-hire
The handover of a leased container to the lessee (on-hire) and its return from lease (off-hire). Containers under an ACEP are examined at these interchanges.
PTI (Pre-Trip Inspection)
The check of a reefer container’s refrigeration unit, carried out before every loading using the manufacturer’s test procedure.
Lashing
Securing the cargo. A lashing report documents that the lashing arrangement and equipment are fit for transport.
Corner casting
The cast-steel blocks at the corners of the container; lifting, stacking and securing are all done at these points. Their dimensions are defined in the ISO 1161 standard, and checking them for cracks is critical during inspection.
Modification
Container modification (modified container)
Turning a standard freight container into an office, café, storage unit, site building or living space through cutting, reinforcement, insulation, electrical and interior fit-out work. More: container modification and the office conversion guide.