ISO Shipping Container Standard
ISO Shipping Container Standard dates to 1968, when the International Organization for Standardization introduced ISO 668, setting common dimensions and ratings so containers from any owner could fit any ship, crane, railcar or truck chassis.
What happened and why it matters
ISO 668 turned the shipping container from a company-specific box into a global, interchangeable unit, which is what made the modern container network possible. Early lines such as Sea-Land and Matson used different box sizes, so equipment could not easily be shared. Through its freight container committee, TC 104, ISO settled on an 8-foot width and standard lengths including 20 and 40 feet, with corner fittings and strength requirements covered in related standards. Ocean freight is still counted and priced on this basis: the twenty-foot equivalent unit, the 40-foot boxes common on Asia to U.S. lanes, and the pallet counts brands plan for each container.