Editing Intermodal container (section)

==Description==
[[File:Container Augsburg.jpg|thumb|{{convert|40|ft|m|adj=on}} containers make up 70% of the world's container volume, which is measured in [[twenty-foot equivalent unit|TEUs]]<ref name=CSIUcontainerfleet/>]]
[[File:Container twistlock connector.agr.jpg|thumb|The standard casting that is located on each of the eight corners of a container. The [[twistlock]]s fit through the larger oval hole on the bottom castings. Top casting ovals hold twistlock fittings used to secure another container on top.]]

Ninety percent of the global container fleet consists of "dry freight" or "general purpose" containers – both of standard and special sizes.<ref name=Production2007>{{cite web |url=https://people.hofstra.edu/geotrans/eng/ch3en/conc3en/containerproduction.html |title=World Container Production, 2007 |author=Jean-Paul Rodrigue |website=The Geography of Transport Systems |publisher=[[Hofstra University]] |access-date=19 July 2015 |archive-url=https://web.archive.org/web/20130704071409/http://people.hofstra.edu/geotrans/eng/ch3en/conc3en/containerproduction.html |archive-date=4 July 2013}}</ref><ref name=ShipCouncilFleet>{{cite web |url=http://www.worldshipping.org/about-the-industry/containers/global-container-fleet |archive-url=https://archive.today/20150511184228/http://www.worldshipping.org/about-the-industry/containers/global-container-fleet |url-status = dead|archive-date=2015-05-11 |title=Global Container Fleet |date=2013 |website=worldshipping.org |publisher=[[World Shipping Council]] |access-date=19 July 2015 }}</ref>
And although lengths of containers vary from {{convert|8|to|56|ft|m|1}}, according to two 2012 container census reports{{#tag:ref|The Containerisation International Market Analysis Report: World Container Census 2012, and the Drewry Maritime Research report: Container Census 2012<ref>{{Cite web |url=https://www.csiu.co/resources-and-links/world-container-fleet |title=World Container Fleet – CSI Container Services International |access-date=22 August 2021 |archive-date=8 March 2022 |archive-url=https://web.archive.org/web/20220308125348/http://www.csiu.co/resources-and-links/world-container-fleet |url-status=dead }}</ref> |group="nb"}} about 80% of the world's containers are either 20- or 40-foot standard-length boxes of the dry freight design.<ref name=CSIUcontainerfleet/> These typical containers are rectangular, closed box models, with doors fitted at one end, and made of [[Roll forming|corrugated]] [[weathering steel]] (commonly known as CorTen){{#tag:ref|Originally "COR-TEN", a trademark of [[U.S. Steel Corporation]]|group="nb"}} with a [[plywood]] floor.<ref>{{cite web|url=http://www.containerhomes-info.com/|title=Shipping Container Homes Globally|access-date=24 May 2009|archive-date=29 May 2009|archive-url=https://web.archive.org/web/20090529033006/http://containerhomes-info.com/|url-status=dead}}</ref> Although corrugating the [[sheet metal]] used for the sides and roof contributes significantly to the container's rigidity and stacking strength, just like in [[Corrugated galvanised iron|corrugated iron]] or in [[Corrugated box design#Stacking strength|cardboard boxes]], the corrugated sides cause aerodynamic drag, and up to 10% fuel economy loss in road or rail transport, compared to smooth-sided vans.<ref>{{cite web|url=http://fleetowner.com/running-green/miles-go|archive-url=https://web.archive.org/web/20150726054227/http://fleetowner.com/running-green/miles-go|url-status = dead|archive-date=26 July 2015|title=Miles to Go – Running Green content from Fleet Owner|date=26 July 2015}}</ref>

Standard containers are {{convert|8|ft|m|1|adj=off}} wide by {{convert|8|ft|6|in|m|1|abbr=on}} high,{{#tag:ref|Using "standard" to mean "standard height", as intended within the ISO 668 standard,<ref name=ISO668/> as opposed to meaning "dry van" or "general purpose" container.<ref name=CSIUcontainerfleet/>|group="nb"}} although the taller "High Cube" or "hi-cube" units measuring {{convert|9|ft|6|in|m|1}} have become very common in recent years{{when?|date=September 2024}}. By the end of 2013, high-cube 40&nbsp;ft containers represented almost 50% of the world's maritime container fleet, according to Drewry's Container Census report.<ref>{{cite web |url=http://www.drewry.co.uk/news.php?id=277 |title=40ft High Cubes set to Dominate the Container Equipment Market |author=<!--Staff writer(s); no by-line.--> |date=18 June 2014 |publisher=Drewry Shipping Consultants |access-date=18 July 2015 | archive-url=https://web.archive.org/web/20140829070535/http://www.drewry.co.uk/news.php?id=277 |archive-date=29 August 2014}}</ref>

About 90% of the world's containers are either [[Real versus nominal value#Measurement|nominal]] {{convert|20|ft|m|1|adj=on}} or {{convert|40|ft|m|1|adj=on}} long,<ref name=CSIUcontainerfleet/><ref name=Globalfleet08>{{cite web |url=https://people.hofstra.edu/geotrans/eng/ch3en/conc3en/containerfleet.html |title=Composition of the Global Fleet of Containers, 2008 |author=<!--Staff writer(s); no by-line.--> |website=The Geography of Transport Systems |publisher=[[Hofstra University]] |access-date=18 July 2015 |archive-url=https://web.archive.org/web/20141121102626/http://people.hofstra.edu/geotrans/eng/ch3en/conc3en/containerfleet.html |archive-date=21 November 2014}}</ref> although the United States and Canada also use longer units of {{cvt|45|ft|m|1}}, {{cvt|48|ft|m|1}} and {{cvt|53|ft|m|1}}. ISO containers have castings with openings for [[twistlock]] fasteners at each of the eight corners, to allow gripping the box from above, below, or the side, and they can be stacked up to ten units high.<ref name=Handbook3.1>{{cite web|url=http://www.containerhandbuch.de/chb_e/stra/stra_03_01_00.html |title=Section 3.1 Container design|work=Container Handbook|publisher=GDV|access-date=2020-05-01}}</ref>

[[File:Containerverriegelung.JPG|thumb|left|[[Twistlock]] on the corner of a road trailer]]
Although ISO standard 1496 of 1990 only required nine-high stacking, ''and only'' of containers rated at {{convert|24000|kg|lb|order=flip}},<ref name=ISO1496-1s>{{cite tech report |url=https://law.resource.org/pub/us/cfr/ibr/004/iso.1496-1.1990.pdf |title=ISO 1496-1: Series 1 Freight Containers – Specification and Testing |number=Part 1 |institution=[[International Organization for Standardization|ISO]] |year=1990 |pages=4–5 |archive-url=https://web.archive.org/web/20140329114253/https://law.resource.org/pub/us/cfr/ibr/004/iso.1496-1.1990.pdf |archive-date=29 March 2014}}</ref> current [[Container ship#Size categories|Ultra Large Container Vessels]] of the Post New Panamax and [[Maersk Triple E-class container ship|Maersk Triple E class]] are stacking them ten or eleven high.<ref>{{cite web |url=https://people.hofstra.edu/geotrans/eng/ch3en/conc3en/containerships.html |title=Evolution of Containerships |author=Jean-Paul Rodrigue |year=2013 |website=The Geography of Transport Systems |publisher=[[Hofstra University]] |access-date=27 July 2015 |archive-url=https://web.archive.org/web/20150322201808/http://people.hofstra.edu/geotrans/eng/ch3en/conc3en/containerships.html |archive-date=2015-03-22}}</ref><ref>{{cite web|url=http://www.maersk.com/en/hardware/triple-e/the-triple-e-a-larger-than-life-puzzle|archive-url=https://web.archive.org/web/20140905104422/http://www.maersk.com/en/hardware/triple-e/the-triple-e-a-larger-than-life-puzzle|url-status = dead|archive-date=5 September 2014|title=The Triple-E A larger-than-life puzzle|date=5 September 2014}}</ref> Moreover, vessels like the [[Maersk Triple E-class container ship#Ships|Marie Maersk]] no longer use separate stacks in their holds, and other stacks above deck – instead they maximize their capacity by stacking continuously from the bottom of the hull, to as much as 21 high.<ref>Archived at [https://ghostarchive.org/varchive/youtube/20211211/l2JMaJTFSvw Ghostarchive]{{cbignore}} and the [https://web.archive.org/web/20210330225921/https://www.youtube.com/watch?v=l2JMaJTFSvw Wayback Machine]{{cbignore}}: {{cite AV media |last=Hammond |first=Richard |title=Episode 4: Mega Ship |url=https://www.youtube.com/watch?v=l2JMaJTFSvw&t=83s |website=Big |time=1:23 |access-date=10 May 2020}}{{cbignore}}</ref> This requires automated planning to keep heavy containers at the bottom of the stack and light ones on top to stabilize the ship and to prevent crushing the bottom containers.

Regional intermodal containers, such as European, Japanese and U.S. domestic units however, are mainly transported by road and rail, and can frequently only be stacked up to two or three laden units high.<ref name=Handbook3.1/> Although the two ends are quite rigid, containers flex somewhat during transport.<ref name="gtri">{{cite web|url=http://www.physorg.com/news171564788.html|title=GTRI Develops New Technologies to Secure Cargo Containers|publisher=PhysOrg.com|date=7 September 2009|access-date=8 May 2011}}</ref>

Container capacity is often expressed in [[twenty-foot equivalent unit]]s ('''TEU''', or sometimes ''teu''). A twenty-foot equivalent unit is a measure of containerized cargo capacity equal to one standard {{convert|20|ft|m|1|adj=on}} long container. This is an approximate measure, wherein the height of the box is not considered. For example, the {{convert|9|ft|6|in|m|1|abbr=on}} tall high-cube, as well as {{convert|4|ft|3|in|m|1|adj=mid|half-height}} {{convert|20|ft|m|1|adj=on}} containers are equally counted as one TEU. Similarly, extra long {{convert|45|ft|m|1|abbr=on|adj=on}} containers are commonly counted as just two TEU, no different from standard {{convert|40|ft|m|1|adj=on}} long units. Two TEU are equivalent to one forty-foot equivalent unit (FEU).<ref>{{cite web|url=http://www.shipping-container-housing.com/20-foot-shipping-container.html|title=The 20 Foot Shipping Container|publisher=Shipping-container-housing.com|access-date=1 February 2013}}</ref><ref>{{cite web|url=https://thanhdocontainer.vn/|title=Thanh Do Container|website= thanhdocontainer.vn }}</ref>

In 2014 the global container fleet grew to a volume of 36.6&nbsp;million TEU, based on Drewry Shipping Consultants' Container Census.<ref name=WcaLoad>{{cite web |url=http://www.wcaworld.com/eng/news.asp?id=1039 |title=Price of new containers at a 10-year low, putting pressure on leasing companies |first=Mike |last=Wackett |date=7 July 2015 |website=The Loadstar |access-date=18 July 2015 |archive-url=https://web.archive.org/web/20150718202001/http://www.wcaworld.com/eng/news.asp?id=1039 |archive-date=18 July 2015}}</ref>{{#tag:ref|Up from an estimated 34.5&nbsp;million TEU in 2013<ref name=ShipCouncilFleet/> |group="nb"}} Moreover, in 2014 for the first time in history 40-foot High-Cube containers accounted for the majority of boxes in service, measured in TEU.<ref name=WcaLoad/> In 2019 it was noted by global logistics data analysis [[startup company|startup]] [[Upply]]<ref>[https://www.mongodb.com/blog/post/upply-is-using-data-to-build-a-new-logistics-market--heres-how Upply is Using Data to Build a New Logistics Market: Here's How | MongoDB News]</ref> that China's role as 'factory of the world' is further incentivizing the use of 40-foot containers, and that the computational standard 1&nbsp;TEU boxes only make up 20% of units on major east–west liner routes, and demand for shipping them keeps dropping.<ref name=Upply19>{{cite web |last=Ricqles |first=Jerome de |title=Containerized sea freight: is it time to switch from TEU to FEU? |url=https://market-insights.upply.com/en/containerized-sea-freight-is-it-time-to-switch-from-teu-to-feu |website=[[Upply]] Transportation and Logistics Analysis |access-date=29 August 2021 |archive-url=https://web.archive.org/web/20201128045643/https://market-insights.upply.com/en/containerized-sea-freight-is-it-time-to-switch-from-teu-to-feu |archive-date=2020-11-28 |date=6 May 2019}}</ref> In the 21st century, the market has shifted to using 40-foot high-cube dry and refrigerated containers more and more predominantly. Forty-foot units have become the standard to such an extent that the sea freight industry now charges less than 30% more for moving a 40-ft unit than for a 1&nbsp;TEU box. Although 20-ft units mostly have heavy cargo, and are useful for stabilizing both ships and revenue,{{#tag:ref |Heavy 1&nbsp;TEU containers are habitually stacked low in a vessel, both for the stability of a ship (keep the [[center of gravity]] low), as well as being often used under long term contracts, providing ''financial'' stability.<ref name=Upply19/> |group=nb }} carriers financially penalize 1&nbsp;TEU boxes by comparison.<ref name=Upply19/>

For container manufacturers, 40-foot High-Cubes now dominate market demand both for dry and refrigerated units.<ref name=Upply19/> Manufacturing prices for regular dry freight containers are typically in the range of $1750–$2000 U.S. per CEU (container equivalent unit),<ref name=WcaLoad/> and about 90% of the world's containers are made in China.<ref name=Globalfleet08/> The average age of the global container fleet was a little over 5 years from end 1994 to end 2009, meaning containers remain in shipping use for well over 10 years.<ref name=WorldCouncilSupply/>

{{multiple image | align=center|total_width=800
|header = Bottom structure features
|image1 = Downburst wind damage vaughan CN rail yard east side near Keele street 23 04 07 (cropped).jpg
|image2 = Inside of a container 1.jpg
|image3 = Schmitz S CF Gooseneck 40 LX.jpg
|image4 = Mckinney Containers.jpg
|footer = The typical ''gooseneck tunnel'' is clearly visible in the underside of a toppled-over, long container (first picture), as well as in a container's interior, where it takes the space otherwise covered by wood flooring. [[Container chassis|Gooseneck container trailer]] showing twistlock couplings for forty-foot boxes at its four corners.

Twenty foot containers, on the other hand, frequently have forklift pockets, accessible from the sides (last picture).{{#tag:ref| Infrequently there are two sets,<ref>[https://commons.wikimedia.org/wiki/File:U.S._Army_Spc._Tashaya_Rodgers,_left,_and_Sgt._Joseph_White,_both_assigned_to_the_551st_Inland_Cargo_Transportation_Company,_secure_a_container_on_a_Palletized_Loading_System_1074_April_21,_2013,_in_Pohang_130421-N-LO372-182.jpg U.S. Army 20-ft ISO container in Pohang, South Korea, 2013]  {{webarchive|url=https://web.archive.org/web/20161022093706/https://commons.wikimedia.org/wiki/File%3AU.S._Army_Spc._Tashaya_Rodgers%2C_left%2C_and_Sgt._Joseph_White%2C_both_assigned_to_the_551st_Inland_Cargo_Transportation_Company%2C_secure_a_container_on_a_Palletized_Loading_System_1074_April_21%2C_2013%2C_in_Pohang_130421-N-LO372-182.jpg |date=22 October 2016 }}</ref> an outer set which may be used for loaded handling, and an inner set only for unloaded handling, by smaller forklifts.<ref name=ISO1496-1>{{cite tech report |url=https://law.resource.org/pub/us/cfr/ibr/004/iso.1496-1.1990.pdf |title=ISO 1496-1: Series 1 Freight Containers – Specification and Testing |number=Part 1 |institution=[[International Organization for Standardization|ISO]] |year=1990 |pages=8, 13, 20 |archive-url=https://web.archive.org/web/20140329114253/https://law.resource.org/pub/us/cfr/ibr/004/iso.1496-1.1990.pdf |archive-date=29 March 2014}}</ref>|group="nb"}}
}}

===Gooseneck tunnel===
A ''gooseneck tunnel'', an indentation in the floor structure, that meshes with the ''gooseneck'' on dedicated container [[Container chassis|semi-trailers]], is a mandatory feature in the bottom structure of 1AAA and 1EEE (40- and 45-ft high-cube) containers, and optional but typical on standard height, forty-foot and longer containers.{{sfnp |ref=ISO668_2013E |ISO:668 (E) |2013 |p=4 }}