A container ship (also called boxship or spelled containership) is a cargo ship that carries all of its load in truck-size intermodal containers, in a technique called containerization. Container ships are a common means of commercial intermodal freight transport and now carry most seagoing non-bulk cargo.
Container ship capacity is measured in twenty-foot equivalent units (TEU). Typical loads are a mix of 20-foot (1-TEU) and 40-foot (2-TEU) ISO-standard containers, with the latter predominant.
Today, about 90% of non-bulk cargo worldwide is transported by container ships, the largest of which, from 2023 onward, can carry over 24,000 TEU.
History
There are two main types of dry cargo: bulk cargo and break bulk cargo. Bulk cargoes, like grain or coal, are transported unpackaged in the hull of the ship, generally in large volume. Break-bulk cargoes, in contrast, are transported in packages, and are generally manufactured goods.From the American Heritage dictionary definition available on-line at .
Before the advent of containerization in the 1950s, break-bulk items required manual loading, lashing, unlashing and unloading from the ship one piece at a time. This stevedoring process became more efficient by grouping cargo into containers, of cargo, or up to about , is moved at once and each container is secured to the ship once in a standardized way.Meurn, 2004, pp. 1–7. Containerization has increased the efficiency of moving traditional break-bulk cargoes significantly, reducing shipping time by 84% and costs by 35%.Bohlman, 2001, p. 13. In 2001, more than 90% of world trade in non-bulk goods was transported in ISO containers.Bohlman, 2001, p. 15. In 2009, almost one quarter of the world's dry cargo was shipped by container, an estimated 125 million TEU or 1.19 billion tonnes worth of cargo.UNCTAD, 2010, p. 84.
The first ships designed to carry standardized load units were used in the late 18th century in England. In 1766 James Brindley designed the box boat "Starvationer" with 10 wooden containers, to transport coal from Worsley Delph to Manchester via the Bridgewater Canal. Before the Second World War, the first container ships were used to carry the baggage of the luxury passenger train from London to Paris (Southern Railway's Golden Arrow / La Flèche d'Or). These containers were loaded in London or Paris, and carried to ports of Dover or Calais on flat cars. In February 1931, the first container ship in the world was launched; the , owned by the Southern Railway. It had 21 slots for containers of Southern Railway.
The earliest container ships after the Second World War were converted oil tankers, built up from surplus T2 tankers after World War II. In 1951, the first purpose-built container vessels began operating in Denmark, and between Seattle and Alaska. The first commercially successful container ship was ,Levinson, 2006, p. 1. a T2 tanker, owned by Malcom McLean, which carried 58 metal containers between Newark, New Jersey and Houston, Texas, on its first voyage.Meurn, 2004, pp. 1–3. In 1955, McLean built his company, McLean Trucking into one of the United States' biggest freighter fleets. In 1955, he purchased the small Pan Atlantic Steamship Company from Waterman Steamship and adapted its ships to carry cargo in large uniform metal containers.Cudahy, 2004, p. 19. On April 26, 1956, the first of these rebuilt container vessels, Ideal X, left the Port Newark in New Jersey and a new revolution in modern shipping resulted.Cudahy, 2004, p. 29.
In the 1950s, a new standardized steel Intermodal container based on specifications from the United States Department of Defense began to revolutionize freight transportation (especially for shipping companies like Seatrain Lines).
The White Pass & Yukon Route railway acquired the world's first purpose-built container ship, the Clifford J. Rogers, built in 1955, and introduced containers to its railway in 1956.
was the world's first fully cellular, purpose-built container ship. and was built by Australian company Associated Steamships, a partnership formed by the 1964 merger of the Adelaide Steamship Company with McIlwraith, McEacharn & Co, then commissioned in May 1964.
Container ships were designed to accommodate intermodal transport of goods, and eliminated requirements for the individual hatches, holds and other dividers of traditional cargo ships. The hull of a typical container ship is similar to an airport hangar, or a huge warehouse, which is divided into individual holding cells, using vertical guide rails. The ship's cells are designed to hold cargo containers, which are typically constructed of steel, though sometimes of aluminum, fiberglass or plywood, and designed for intermodal transfers between ship and train, truck or semi-trailer. Shipping containers are categorized by type, size and function.
Today, about 90% of non-bulk cargo worldwide is transported by container by about 50,000 container ships. Modern container ships can carry over 24,000 TEU. The largest container ships measure about in length, and carry loads equal to the cargo-carrying capacity of sixteen to seventeen pre-World War II freighter ships.
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.Hayler & Keever, 2004, p. 15-2. Into this frame is set one or more below-deck cargo 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. 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. The beams not only support the deck, but along with the deck, frames, and transverse bulkheads, strengthen and reinforce the shell. 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.Hayler & Keever, 2004, p. 15-3. The double-bottoms generally hold liquids such as fuel oil, ballast water or fresh water.
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. In most new ships, the engine room is located in the aft portion.
Size categories
Container ships are distinguished into 7 major size categories: small feeder, feeder, feedermax, Panamax, Post-Panamax, Neopanamax and ultra-large. 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.Vesterager, Jacob. "Alphaliner: Verdens havne er ikke klar til gigantskibe" (World ports not ready for giant ships). ShippingWatch, December 2012.
The size of a Panamax vessel is limited by the original Panama canal's lock chambers, which can accommodate ships with a beam of up to 32.31 m, a length overall of up to 294.13 m, and a draft of up to 12.04 m.Autoridad del Canal de Panamá 2005, pp. 1112. The Post-Panamax category has historically been used to describe ships with a moulded breadth over 32.31 m,UNCTAD, 2010, p. xiii. 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. The third set of locks were built to accommodate a container ship with a length overall of , a maximum beam (width) of , and tropical fresh-water draft of .Autoridad del Canal de Panamá, 2009.Autoridad del Canal de Panamá, 2006, p. 45. 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.
Container ships under 3,000 TEU are generally called feeder ships 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.McNicholas, p. 45. This size of vessel is the most likely to carry cargo cranes on board.
+ Container ship size categories Name Capacity(TEU)MAN Diesel, 2009, p.6. Length Beam Draft ExampleUltra Large Container Vessel (ULCV)14,501 and higher and longer and wider 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.Photo: MV Mærsk Mc-Kinney Møller New Panamax (or Neopanamax)10,000–14,500 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.Photo: The 9,500 TEU pierside in Hamburg Post-Panamax5,101–10,000Panamax3,001–5,100 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.Photo: The 4,224 TEU MV Providence Bay passing through the Panama CanalFeedermax2,001–3,000 Container ships under 3,000 TEU are typically called feeders. In some areas of the world, they might be outfitted with cargo cranes.Photo: The 384 TEU at anchor Feeder1,001–2,000Small feederUp to 1,000
Cargo cranes
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.UNCTAD, 2010, p. 32. 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.
While geared container ships are more flexible in that they can visit ports that are not equipped with pierside container cranes, they suffer from several drawbacks. To begin with, geared ships will cost more to purchase than a gearless ship. Geared ships also incur greater recurring expenses, such as maintenance and fuel costs. 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".
Instead of the rotary cranes, some geared ships have gantry cranes installed.Conrad, 1989, p. 249. These cranes, specialized for container work, are able to roll forward and aft on rails. In addition to the additional capital expense and maintenance costs, these cranes generally load and discharge containers much more slowly than their shoreside counterparts.
The introduction and improvement of shoreside container cranes have been a key to the success of the container ship. The first crane that was specifically designed for container work was built in California's Port of Alameda in 1959. By the 1980s, shoreside gantry cranes were capable of moving containers on a 3-minute-cycle, or up to 400 tons per hour. In March 2010, at Port Klang in Malaysia, a new world record was set when 734 container moves were made in a single hour.UNCTAD, 2010, p. 100. The record was achieved using 9 cranes to simultaneously load and unload , a ship with a capacity of 9,600 TEU.