Merikontti

A merikontti, or sea container, is a standardized reusable container used for transporting goods by sea and other modes. It is designed to be weatherproof, secure, and compatible with handling equipment such as cranes and forklifts, enabling efficient intermodal transfer between ships, trucks, and trains.

The most common sizes are 20-foot and 40-foot containers. External dimensions for a 20-foot container are about 6.058 meters in length, 2.438 meters in width, and 2.591 meters in height; high-cube variants increase height to about 2.89 meters. A 40-foot container is about 12.192 meters long, with the same width and a typical height of 2.896 meters. These specifications are defined by ISO standards (such as ISO 668 and ISO 1161) and refer to exterior measurements; interior space varies with wall thickness and insulation in certain models.

Most merikontti are constructed from steel with corrugated walls and corner posts. Corner castings at each corner enable stacking and securement with twist locks. Containers carry a CSC plate, under the International Convention for Safe Containers, that records the maximum gross mass and other safety data. They are designed for long service life and recyclability.

Common types include dry containers for general cargo, refrigerated containers (reefer) for temperature-controlled goods, open-top or open-side variants, flat racks for oversized cargo, and tank containers for liquids or gases.

Uses include international and domestic freight, port storage, and temporary on-site space such as offices or workshops. Containerization, which began in the 1950s and 1960s, revolutionized global trade by standardizing packaging and enabling rapid, efficient transfer across multiple transport modes.