ISO 668

ISO 668
Series 1 freight containers – Classification, dimensions and ratings
AbbreviationISO 668:2020
Latest version7
668:2020
Preview versionSixth edition
2013-08-01
OrganizationInternational Organization for Standardization
CommitteeTechnical Committee ISO/TC 104: Freight containers, Subcommittee SC 1: General purpose containers

ISO 668 – Series 1 freight containers – Classification, dimensions and ratings is an ISO international standard which nominally classifies intermodal freight shipping containers, and standardizes their sizes, measurements and weight specifications.[1]

The current version of the standard is the Seventh edition (2020), which integrates version E. The standard was prepared by Technical Committee ISO/TC 104: Freight containers, Subcommittee SC 1: General purpose containers.[2]

Introduced in 1968, ISO 668 currently regulates both external and internal dimensions of containers, as well as the minimum door opening sizes, where applicable. Minimum internal dimensions were earlier defined by ISO standard 1894: 'General purpose series 1 freight containers – Minimum internal dimensions'.[3] Its second edition appeared in 1979, but was withdrawn, once revised by ISO 1496‑1 of 1990.[4] The current version of ISO 1496‑1 is 2013, including Amendment 1 of 2016,[5] last reviewed and reconfirmed in 2019.[6]

ISO 668 also specifies the respective associated gross weight ratings, and includes requirements for load transfer areas in the base structures of containers, since Amendment 1 of 2005.[7] Amendment 2 of 2005 further added 45 foot length containers to the standard.[7]

The maximum gross mass (MGM) rating of 20- and 30-foot length units was notably increased to 30,480 kg (67,200 lb) (67,200 lbs) by Amendment 1 of 2005.[7] Until then, the MGM for 20-foot units was 24,000 kg (52,910 lb) (52,900 lbs), and for 30-foot boxes 25,400 kg (56,000 lb) (56,000 lbs). However, since Amendment 2 of 2016, the maximum gross mass for ISO-standard Series 1 containers of all sizes, (except 10‑foot units), has most recently been further increased to a maximum of 36,000 kg (79,370 lb).[8] Draft Amendment 1 of ISO 668: 2020 – for the eighth edition – maintains this.[9]

A separate standard is set for the required stacking strength, or 'maximum superimposed mass' (MSM) for standard containers. The ISO standard for Series 1 containers, ISO 1496‑1, established this, among other characteristics, for many years set at 192,000 kg (423,300 lb).[10] However, in order to keep pace with the increase of container maximum gross weight, the continuing growth in container ship size, and the related height of container stacks on board the ships, the required stacking strength was increased to a superimposed weight of 213,360 kg (470,400 lb) in 2005 per Amendment 3.[8] This value was since maintained in the latest revision of Standard 1496‑1 (2013). Production statistics show that the vast majority of containers have, for many years, been built with a stacking strength at or above the 213,000 kg[clarification needed] figure stipulated in ISO 1496‑1. In fact, most major container operators and lessors now cause containers to be built above the required figure, with the most common superimposed strength being 216,000 kg (476,200 lb).[8]

  1. ^ "ISO 668:2020 – Series 1 freight containers – Classification, dimensions and ratings". www.iso.org.
  2. ^ ISO std. 668:2020 – Series 1 freight containers – Classification, dimensions and ratings | Amendment 1 (preview)
  3. ^ Cite error: The named reference 20FtStdSpec was invoked but never defined (see the help page).
  4. ^ ISO 1894:1979, Withdrawal. ISO. Archived 2020-10-22 at the Wayback Machine
  5. ^ ISO 1496‑1:2013 Amendment 1 (2016) – Series 1 freight containers; Specification and testing – Part 1 General purpose cargo containers. ISO. Archived 2020-04-27 at the Wayback Machine
  6. ^ ISO 1496‑1:2013 - Series 1 freight containers; Specification and testing – Part 1 General purpose cargo containers. ISO. Archived 2020-04-27 at the Wayback Machine
  7. ^ a b c ISO 668:1995 Series 1 freight containers – Classification, dimensions and ratings – Amendment 1 & 2 (Technical report). ISO. 2005-10-01.
  8. ^ a b c Sub-committee on Carriage of Cargoes and Containers (5 July 2019). Discrepancy in container stacking strength requirements between the pertinent ISO Standard and the Convention for Safe Containers (CSC) (PDF) (6th session; Agenda item 13 ed.). International Maritime Organization. pp. 1–2. Archived (PDF) from the original on 2021-09-16. Retrieved 16 September 2021.
  9. ^ Draft Amendment ISO 668:2020/DAM 1
  10. ^ ISO 1496‑1:1990, Preceded by Amendments 1:1993, and 2:1998