Editing Container ship (section)

===Cargo holds===
Efficiency has always been key in the design of container ships.<ref name="meurn-1-16">Meurn & Sauerbier, 2004, pp. 1–16.</ref>  While containers may be carried on conventional break-bulk ships, cargo holds for dedicated container ships are specially constructed to speed loading and unloading, and to efficiently keep containers secure while at sea.<ref name="meurn-1-16"/>  A key aspect of container ship specialization is the design of the hatches, the openings from the main deck to the cargo holds.<ref name="haykey5-10">Hayler & Keever, 2004, pp. 5–10.</ref>  The hatch openings stretch the entire breadth of the cargo holds, and are surrounded by a raised steel structure known as the ''hatch [[coaming]]''.<ref name="meurn-1-16"/><ref name="haykey5-10"/>  On top of the hatch coamings are the hatch covers.  Until the 1950s, hatches were typically secured with wooden boards and tarpaulins held down with battens.<ref name="haykey5-9-5-10">Hayler & Keever, 2004, pp. 5-9 – 5-10.</ref>  Today, some hatch covers can be solid metal plates that are lifted on and off the ship by cranes, while others are articulated mechanisms that are opened and closed using powerful hydraulic rams.

Another key component of dedicated container-ship design is the use of ''cell guides''.<ref name="meurn-1-16"/>  Cell guides are strong vertical structures constructed of metal installed into a ship's cargo holds.<ref name="meurn-1-16"/>  These structures guide containers into well-defined rows during loading and provide some support for containers against the ship's rolling at sea.<ref name="meurn-1-16"/>  So fundamental to container ship design are cell guides that organizations such as the [[United Nations Conference on Trade and Development]] use their presence to distinguish dedicated container ships from general break-bulk cargo ships.<ref name="unctad-xiii"/>

A system of three dimensions is used in [[Stowage plan for container ships|cargo plans]] to describe the position of a container aboard the ship.<ref name="meurn-1-19-21">Meurn & Sauerbier, 2004, p. 1-19–1-21.</ref>  The first coordinate is the ''bay'', which starts at the front of the ship and increases aft.<ref name="meurn-1-19-21"/>  The second coordinate is the ''row''.<ref name="meurn-1-19-21"/>  Rows on the starboard side are given odd numbers and those on the port side are given even numbers.<ref name="meurn-1-19-21"/>  The rows nearest the centerline are given low numbers, and the numbers increase for slots further from the centerline.<ref name="meurn-1-19-21"/> The third coordinate is the ''tier'', with the first tier at the bottom of the cargo holds, the second tier on top of that, and so forth.<ref name="meurn-1-19-21"/>

Container ships typically take 20 foot and 40 foot containers. Some ships can take 45 footers above deck.  A few ships (APL since 2007,<ref>{{cite web | url = https://www.marinelink.com/news/oceancapable-containers315927 | title = APL to Take Delivery of First 'Ocean-capable' 53-foot Containers  | website = www.marinelink.com  | date = 31 October 2007 | access-date = 26 March 2024}}</ref> Carrier53 since 2022 <ref>{{cite web | url = https://www.carrier53.com | title = Tailor made dedicated 53FT shipping service | website = www.carrier53.com  | access-date = 26 March 2024}}</ref>) can carry 53 foot containers. 40 foot containers are the primary container size, making up about 90% of all container shipping and since container shipping moves 90% of the world's freight, over 80% of the world's freight moves via 40 foot containers.