Editing Container ship (section)

==Architecture==
There are several key points in the design of modern container ships.  The hull, similar to that of bulk carriers and general cargo ships, is built around a strong [[keel]].<ref name="hay-kee-15-2">Hayler & Keever, 2004, p. 15-2.</ref>  Into this frame is set one or more below-deck cargo [[Hold (ship)|holds]], numerous tanks, and the [[engine room]].  The holds are topped by hatch covers, onto which more containers can be stacked.  Many container ships have cargo cranes installed on them, and some have specialized systems for securing containers on board.

The hull of a modern cargo ship is a complex arrangement of steel plates and strengthening beams.  Resembling ribs, and fastened at right angles to the keel, are the ship's frames.<ref name="hay-kee-15-2"/>  The ship's main deck, the metal platework that covers the top of the hull framework, is supported by beams that are attached to the tops of the frames and run the full breadth of the ship.<ref name="hay-kee-15-2"/>  The beams not only support the deck, but along with the deck, frames, and transverse bulkheads, strengthen and reinforce the shell.<ref name="hay-kee-15-2"/>  Another feature of recent hulls is a set of double-bottom tanks, which provide a second watertight shell that runs most of the length of a ship.<ref name="hay-kee-15-3">Hayler & Keever, 2004, p. 15-3.</ref>  The double-bottoms generally hold liquids such as fuel oil, ballast water or fresh water.<ref name="hay-kee-15-3"/>

A ship's engine room houses its main engines and auxiliary machinery such as the fresh water and sewage systems, electrical generators, fire pumps, and air conditioners.<ref name="hay-kee-15-3"/>  In most new ships, the engine room is located in the aft portion.<ref name="hay-kee-15-3"/><!--there's a bit more on 15-5, but it doesn't seem that important at the moment -->

=== Size categories ===
[[File:20240330 Container ship sizes and capacities.svg|thumb|The size of the ''[[MV Dali]]'', involved in the 2024 [[Francis Scott Key Bridge collapse]], though considered large, is less than that of the largest container ship.<ref name=NYTimes_20240328/> It is recognized that bigger ships can cause bigger disasters, such as the 1,300-foot vessel in the [[2021 Suez Canal obstruction]].<ref name=NYTimes_20240328>{{cite news |last1=Koeze |first1=Ella |title=The Dali Is a Big Ship. But Not the Biggest. |url=https://www.nytimes.com/interactive/2024/03/28/business/economy/big-ship-dali-baltimore.html |work=The New York Times |date=March 28, 2024 |archive-url=https://web.archive.org/web/20240330113653/https://www.nytimes.com/interactive/2024/03/28/business/economy/big-ship-dali-baltimore.html |archive-date=March 30, 2024 |url-status=live }} Source credits: "Sources: "The Geography of Transport Systems," by Jean-Paul Rodrigue; VesselFinder; the Empire State Building; the Eiffel Tower; ShipHub; Maryland Port Administration".</ref>]]
Container ships are distinguished into 7 major size categories: small feeder, feeder, feedermax, [[Panamax]], [[Post-Panamax]], [[Neopanamax]] and ultra-large.<ref name="man"/> As of December 2012, there were 161 container ships in the VLCS class (Very Large Container Ships, more than 10,000 TEU), and 51 ports in the world can accommodate them.<ref>Vesterager, Jacob. "[http://shippingwatch.dk/Havne/article4943407.ece Alphaliner: Verdens havne er ikke klar til gigantskibe]" (World ports not ready for giant ships). ShippingWatch, December 2012.</ref>

The size of a Panamax vessel is limited by the original [[Panama Canal Locks|Panama canal's lock chambers]], which can accommodate ships with a beam of up to 32.31&nbsp;m, a length overall of up to 294.13&nbsp;m, and a draft of up to 12.04&nbsp;m.<ref>Autoridad del Canal de Panamá 2005, pp. 11{{spaced ndash}}12.</ref>  The Post-Panamax category has historically been used to describe ships with a moulded breadth over 32.31&nbsp;m,<ref name="unctad-xiii">UNCTAD, 2010, p. xiii.</ref> however the [[Panama Canal expansion project]] has caused some changes in terminology.  The Neopanamax category is based on the maximum vessel size that is able to transit a new third set of locks, which opened in June 2016.<ref name=NYT062016>{{cite news | url=https://www.nytimes.com/aponline/2016/06/26/world/americas/ap-lt-panama-canal-expansion.html?ref=world&_r=0 | title=Panama Canal Opens $5B Locks, Bullish Despite Shipping Woes | author=The Associated Press | work=[[The New York Times]] | date=2016-06-26 | access-date=2016-06-26| author-link=The Associated Press }}</ref><ref name="pc-np"/> The third set of locks were built to accommodate a container ship with a [[length overall]] of {{convert|366|m}}, a maximum beam (width) of {{convert|49|m}}, and tropical fresh-water draft of {{convert|15.2|m}}.<ref name="pc-np">Autoridad del Canal de Panamá, 2009.</ref><ref name="pc45">Autoridad del Canal de Panamá, 2006, p. 45.</ref> Such a vessel, called Neopanamax class, is wide enough to carry 19 columns of containers, can have a total capacity of approximately 12,000 TEU and is comparable in size to a [[capesize]] bulk carrier or a [[Suezmax]] tanker.<ref name="pc45"/>

Container ships under 3,000 TEU are generally called [[feeder ship]]s or feeders.  They are small ships that typically operate between smaller container ports.  Some feeders collect their cargo from small ports, drop it off at large ports for transshipment on larger ships, and distribute containers from the large port to smaller regional ports.<ref name="mcnich-45">McNicholas, p. 45.</ref>  This size of vessel is the most likely to carry cargo cranes on board.<ref name="unctad32"/>

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{| class="wikitable plainrowheaders"
|+ Container ship size categories
! Name
! Capacity<br />([[Twenty-foot equivalent unit|TEU]])<ref name="man">MAN Diesel, 2009, p.6.</ref>
! [[Length overall|Length]]
! [[Beam (nautical)|Beam]]
! [[Draft (hull)|Draft]]
! colspan="2" | Example
|-
|Ultra Large Container Vessel (ULCV)
|14,501 and higher
|{{convert|1200|ft|m|0|abbr=on}} and longer
|{{convert|160.7|ft|m|0|abbr=on}} and wider
|{{convert|49.9|ft|m|1|abbr=on}} and deeper
| With a length of 400 m, a beam of 59 m, draft of 14.5 m, and a capacity of 18,270 TEU, ships of the [[Maersk Triple E class]] are able to transit the Suez canal.<ref>{{csr|register=ABS|id=13232687|shipname=Mærsk Mc-Kinney Møller|access-date=1 May 2014}}<br />{{cite book|last1=van Ham|first1=Hans|last2=Rijsenbrij|first2=Joan Rijsenbrij|title=Development of containerization success through vision, drive and technology|date=2012|publisher=IOS Press|location=Amsterdam|isbn=9781614991472|page=290|url=https://books.google.com/books?id=CgQmkTczzPwC&q=%22draft%22+%22triple+e%22+14.5&pg=PA290|edition=Online-Ausg.}}</ref><br>Photo: [[Mærsk Mc-Kinney Møller (ship)|MV ''Mærsk Mc-Kinney Møller'']]
| [[File:Mærsk Mc-Kinney Møller passing Port Said in the Suez Canal on its maiden voyage.jpg|150px]]
|-
|[[New Panamax]] (or Neopanamax)
|10,000–14,500
| rowspan="2" | {{convert|1200|ft|m|0|abbr=on}}
| rowspan="2" | {{convert|160.7|ft|m|0|abbr=on}}
| rowspan="2" | {{convert|49.9|ft|m|1|abbr=on}}
| rowspan="2" | With a beam of 43 m, ships of the ''COSCO Guangzhou'' class are much too big to fit through the Panama Canal's old locks, but could easily fit through the new expansion.<br>Photo:  The 9,500 TEU {{MV|COSCO Guangzhou}} pierside in Hamburg
| rowspan="2" | [[File:COSCO Guangzhou 02 (RaBoe).jpg|150px]]
|-
|[[Post-Panamax]]
|5,101–10,000
|-
|[[Panamax]]
|3,001–5,100
| {{convert|965|ft|m|2|abbr=on}}<br>
| {{convert|106|ft|m|2|abbr=on}}
| {{convert|39.5|ft|m|2|abbr=on}}
|Ships of the Bay class are at the upper limit of the Panamax class, with an overall length of 292.15 m, beam of 32.2m, and maximum depth of 13.3 m.<ref>{{cite web|url=http://www.reedereibluestar.de/fleet/fleet-list/bay-class-overview.html |title=Bay Class Overview |author=Reederei Blue Star GmbH |author-link=Reederei Blue Star GmbH |year=2011 |work=Reederei Blue Star Fleet |publisher=Reederei Blue Star GmbH |location=Hamburg |access-date=2011-03-05 |url-status=dead |archive-url=https://web.archive.org/web/20110719074522/http://www.reedereibluestar.de/fleet/fleet-list/bay-class-overview.html |archive-date=July 19, 2011 }}</ref><br>Photo: The 4,224 TEU MV ''Providence Bay'' passing through the Panama Canal
|[[File:Panama Kanal 01 (40).jpg|150px]]
|-
|Feedermax
|2,001–3,000
| rowspan="3" |
| rowspan="3" |
| rowspan="3" |
| rowspan="3" | Container ships under 3,000 TEU are typically called feeders. In some areas of the world, they might be outfitted with cargo cranes.<br>Photo: The 384 TEU {{MV|TransAtlantic}} at anchor<ref name="fearnleys">{{cite web |url=http://www.fearnsale.com/asset/68/1/68_1.pdf |title= Fearnley's Annual Review, 2004|access-date=2011-03-05 |author=Fearnresearch|year=2005 |publisher=Fearnleys AS|location=Oslo|page=90}}</ref>
| rowspan="3" | [[File:MV TransAtlantic.jpg|150px]]
|-
|[[Feeder ship|Feeder]]
|1,001–2,000
|-
|Small feeder
|Up to 1,000
|}

===Cargo cranes===
{{see also|Lift-on/lift-off}}
[[File:US Navy 110303-M-0074F-169 A crane offloads a beach landing module from USNS Sgt. William Button (T-AK 3012) near Camp Pendleton, Calif., during Pa.jpg|thumb|Cargo cranes on a US navy container ship]]

A major characteristic of a container ship is whether it has cranes installed for handling its cargo.  Those that have cargo cranes are called ''geared'' and those that do not are called ''ungeared'' or ''gearless''.  The earliest purpose-built container ships in the 1970s were all gearless.<ref name="unctad32">UNCTAD, 2010, p. 32.</ref>  Since then, the percentage of geared newbuilds has fluctuated widely, but has been decreasing overall, with only 7.5% of the container ship capacity in 2009 being equipped with cranes.<ref name="unctad32"/>

While geared container ships are more flexible in that they can visit ports that are not equipped with pierside [[container crane]]s, they suffer from several drawbacks.<ref name="unctad32"/>  To begin with, geared ships will cost more to purchase than a gearless ship.<ref name="unctad32"/>  Geared ships also incur greater recurring expenses, such as maintenance and fuel costs.<ref name="unctad32"/>  The United Nations Council on Trade and Development characterizes geared ships as a "niche market only appropriate for those ports where low cargo volumes do not justify investment in port cranes or where the public sector does not have the financial resources for such investment".<ref name="unctad32"/>

Instead of the rotary cranes, some geared ships have [[gantry crane]]s installed.<ref name="con249">Conrad, 1989, p. 249.</ref>  These cranes, specialized for container work, are able to roll forward and aft on rails.<ref name="con249"/>  In addition to the additional capital expense and maintenance costs, these cranes generally load and discharge containers much more slowly than their shoreside counterparts.<ref name="con249"/>

The introduction and improvement of shoreside [[container crane]]s have been a key to the success of the container ship.<ref name="con249"/>  The first crane that was specifically designed for container work was built in California's Port of Alameda in 1959.<ref name="con249"/>  By the 1980s, shoreside gantry cranes were capable of moving containers on a 3-minute-cycle, or up to 400 tons per hour.<ref name="con249"/> In March 2010, at [[Port Klang]] in Malaysia, a new world record was set when 734 container moves were made in a single hour.<ref name="unctad100">UNCTAD, 2010, p. 100.</ref> The record was achieved using 9 cranes to simultaneously load and unload {{MV|CSCL Pusan}}, a ship with a capacity of 9,600 TEU.<ref name="unctad100"/>

Vessels in the 1,500–2,499 TEU range are the most likely size class to have cranes, with more than 60% of this category being geared ships.<ref name="unctad32"/>  Slightly less than a third of the very smallest ships (from 100–499 TEU) are geared, and almost no ships with a capacity of over 4,000 TEU are geared.<ref name="unctad32"/>

[[File:Containerladeräume Schiff retouched.jpg|thumb|A view into the holds of a container ship. The vertical cell guides organize containers [[athwartships]].]]

===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.

===Lashing systems===
[[File:Manual twistlock.jpg|thumb|right|Twist-locks and lashing rods (''pictured'') are widely used to secure containers aboard ships.]]

Numerous systems are used to secure containers aboard ships, depending on factors such as the type of ship, the type of container, and the location of the container.<ref name="meurn-1-35">Meurn and Sauerbier, 2006, p. 1-35.</ref><ref name="peck and hale">Peck and Hale, 2000, p. 1-4.</ref>  Stowage inside the holds of fully cellular (FC) ships is simplest, typically using simple metal forms called container guides, locating cones, and anti-rack spacers to lock the containers together.<ref name="peckhale2">Peck and Hale, 2000, p. 2.</ref>  Above-decks, without the extra support of the cell guides, more complicated equipment is used.<ref name="meurn-1-35"/>  Three types of systems are currently in wide use: lashing systems, locking systems, and buttress systems.<ref name="meurn-1-35"/>  Lashing systems secure containers to the ship using devices made from wire rope, rigid rods, or chains and devices to tension the lashings, such as turnbuckles.<ref name="meurn-1-35"/>  The effectiveness of lashings is increased by securing containers to each other, either by simple metal forms (such as stacking cones) or more complicated devices such as twist-lock stackers.<ref name="meurn-1-35"/>  A typical [[twist-lock]] is inserted into the casting hole of one container and rotated to hold it in place, then another container is lowered on top of it.<ref name="peckhale12">Peck and Hale, 2000, p. 12.</ref>  The two containers are locked together by twisting the device's handle.<ref name="peckhale12"/>  A typical [[twist-lock]] is constructed of forged steel and ductile iron and has a shear strength of 48 tonnes.<ref name="peckhale10">Peck and Hale, 2000, p. 10.</ref>

The buttress system, used on some large container ships, uses a system of large towers attached to the ship at both ends of each cargo hold.<ref name="meurn-1-38-0">Meurn and Sauerbier, 2006, p. 1-38–1-40.</ref>  As the ship is loaded, a rigid, removable stacking frame is added, structurally securing each tier of containers together.<ref name="meurn-1-38-0"/>

===Bridge===
Container ships have typically had a single bridge and accommodation unit towards the rear, but to reconcile demand for larger container capacity with [[SOLAS Convention|SOLAS]] visibility requirements, several new designs have been developed. {{As of|2015}}, some large container ships are being developed with the bridge further forward, separate from the exhaust stack. Some smaller container ships working in European ports and rivers have liftable wheelhouses, which can be lowered to pass under low bridges.