A Container is a standardized steel box designed to move goods between modes of transport — ocean vessel, rail, and truck — without unpacking. Built to ISO 668 dimensions and ISO 1496 specifications, containers are the unit of containerization.
Common types:
- Dry container (DC) — the standard general-cargo box. Lengths of 20', 40', and 45'. Heights of 8'6" (standard) or 9'6" (high-cube, HC).
- Reefer (RF) — refrigerated. Built-in refrigeration unit; runs on vessel power at sea and on generator (genset) over the road. Used for perishables (produce, pharmaceuticals).
- Open top (OT) — removable canvas roof; used for cargo that loads from above (machinery) or exceeds standard internal height.
- Flat rack (FR) — collapsible sides; used for oversize or heavy-lift cargo (yachts, transformers, industrial equipment).
- Tank — for bulk liquids and gases.
Every container carries an 11-character identifier under ISO 6346 — four-letter owner prefix (e.g., MSCU for MSC), a six-digit serial, and a check digit (e.g., MSCU 123456-7). This is the identifier used in AMS, bills of lading, and terminal systems.
Volumes by type (approximate, depends on tare):
- 20' DC — 33 CBM, 28,000 kg max gross
- 40' DC — 67 CBM, 30,500 kg max gross
- 40' HC — 76 CBM, 30,500 kg max gross
- 45' HC — 86 CBM, 30,500 kg max gross
Ownership is split between liner carriers, leasing companies (Triton, Beacon, SeaCo), and a small number of large shippers with their own fleets.