Container ships are cargo ships that carry all of their load in truck-size containers, in a technique called containerization. They form a common means of commercial intermodal freight transport.
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The earliest container ships were converted 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. On November 26, 1955 the purpose-built container ship Clifford J. Rodgers,[1] carried 600 containers between North Vancouver, British Columbia and Skagway, Alaska.
The first purpose-built container ship in the United States was the Ideal-X [2], a converted T2, owned by Malcom McLean, which carried 58 metal containers between Newark, New Jersey and Houston, Texas on its first voyage, in April 1956.
Today, approximately 90% of non-bulk cargo worldwide is transported by container, and modern container ships can carry up to 15,000 twenty-foot equivalent units (TEU). As a class, container ships now rival crude oil tankers and bulk carriers as the largest commercial vessels on the ocean.
Container ships are designed so that no space is wasted. Capacity is measured in Twenty-foot equivalent unit (TEU), the number of standard 20-foot containers measuring 20 × 8.0 × 8.5 feet (6.1 × 2.4 × 2.6 metres) a vessel can carry. This not withstanding, most containers used today measure 40 feet (12 metres) in length. Above a certain size, container ships do not carry their own loading gear, so loading and unloading can only be done at ports with the necessary cranes. However, smaller ships with capacities up to 2,900 TEU are often equipped with their own cranes.
Informally known as "box boats," they carry the majority of the world's dry cargo, meaning manufactured goods. Cargoes like metal ores or coal or wheat are carried in bulk carriers. There are large main line vessels that ply the deep sea routes, then many small "feeder" ships that supply the large ships at centralized hub ports. Most container ships are propelled by diesel engines, and have crews of between 20 and 40 people. They generally have a large accommodation block at the stern, near the engine room. Container ships now carry up to 15,000 TEU (approximately equivalent to 35 100-car double-stack intermodal freight trains) on a voyage. The world's largest container ship, the M/V Emma Mærsk has a capacity of 15,200 containers.[3]
In 2008 the Korean shipbuilder STX announced plans to construct a container ship capable of carrying 22,000 TEU,[4] and with a proposed length of 450 metres and a beam of 60 metres.[5] If constructed, the container ship would the largest seagoing vessel in the world.[6]
Large container ships (over 7,000 TEU) have been built in the following shipyards:
The ceaseless transit of these containers (at any given time, between 5 million and 6 million units) entails a great deal of risk.
Some of the risks are linked to the loading and unloading of containers. The risks involved in these operations affect both the cargo being moved onto or off the ship, as well as the ship itself. Containers, due to their fairly nondescript nature and the sheer number handled in major ports, require complex organization to ensure they are not lost, stolen or misrouted. In addition, as the containers and the cargo they contain make up the vast majority of the total weight of a cargo ship, the loading and unloading is a delicate balancing act, as it directly affects the centre of mass for the whole ship. There have been some instances of poorly-loaded ships capsizing at the pier as a result.
Maneuvers in coastal waters and ports managed in the wheel house may be dangerous, as evidenced by a container ship hitting the San Francisco – Oakland Bay Bridge on November 7, 2007.[7]
It has been estimated that container ships lose over 10,000 containers at sea each year.[8] Most go overboard on the open sea during storms but there are some examples of whole ships being lost with their cargo. When containers are dropped, they immediately become an environmental threat — termed "marine debris".
Cargo too large to carry in containers can be handled using flat racks, open top containers and platforms. There are also container ships called roll-on/roll-off (RORO), which utilize shore-based ramp systems for loading and unloading. ROROs are usually associated with shorter trade routes, as they are unable to carry the volume of crane-based container vessels. However, due to their flexibility and high speed, ROROs are frequently used in today's container markets.
Economies of scale have dictated an upward trend in sizes of container ships in order to reduce costs. One limit on ship size is the "Suezmax" standard, or the largest theoretical ship capable of passing through the Suez Canal, which measures 14,000 TEU. Such a vessel would displace 137,000 metric tons of deadweight (DWT), be 400 meters long, more than 50 meters wide, have a draft of nearly 15 metres, and use more than 85 MW (113,987hp) to achieve 25.5 knots, specifications met by the Emma Mærsk.
Beyond Suezmax lies the "Malaccamax" (for Straits of Malacca) ship of 18,000 TEU, displacing 300,000 DWT, 470 meters long, 60 meters wide, 16 meters of draft, and using more than 100 MW (134,102hp) for 25.5 knots. This is most likely the limit before a major restructuring of world container trade routes.[9] The biggest constraint of this design, the absence of a capable single engine, has been overcome by the MAN B&W K108ME-C.
The ultimate problem was the absence of a manufacturer capable of producing the propeller needed for transmitting this power, which would be about 10 metres in diameter, and weigh 130 tonnes. One has since been built for the Emma Mærsk by Mecklenburger Metallguss GmbH in Waren, Germany. Other constraints, such as time in port and flexibility of service routes are similar to the constraints that eventually limited the growth in size of supertankers.
Built | Name | Sisterships | Length o.a. | Beam | Maximum TEU | GT | Owners | Flag |
---|---|---|---|---|---|---|---|---|
2006 | Emma Mærsk | 6 | 397.7 m | 56.4 m | 15,200 | 151,687 | Maersk Line | Denmark |
2005 | Gudrun Mærsk | 5 | 367.3 m | 42.8 m | 10,150 | 97,933 | Maersk Line | Denmark |
2006 | Xin Los Angeles | 6 | 336.7 m | 45.6 m | 9,600 [10] | 107,200 | CSCL | Hong Kong |
2006 | COSCO Guangzhou | 4 | 350 m | 42.8 m | 9,450[11] | 99,833 | COSCO | Greece |
2006 | CMA CGM Medea | 3 | 350 m | 42.8 m | 9,415[12] | 99,500 | CMA CGM | France |
2003 | Axel Mærsk | 5 | 352.6 m | 42.8 m | 9,310 | 93,496 | Maersk Line | Denmark |
2006 | NYK Vega | 2 | 338.2 m | 45.6 m | 9,200 | 97,825 | Nippon Yusen Kaisha | Panama |
2005 | MSC Pamela | 5 | 336.7 m | 45.6 m | 9,178 | 90,500 | MSC | Liberia |
2006 | MSC Madeleine | 1 | 348.5 m | 42.8 m | 9,100 | 107,551 | MSC | Liberia |
2006 | Hannover Bridge | 2 | 336 m | 45.8 m | 9,040 | 89,000 | K Line | Japan |
Note: "TEU" stands for "Twenty-foot Equivalent Unit," i.e. a 20 foot shipping container. Thus a 40 foot container is 2 TEU, etc.
Rank | Port | Country | TEUs (000s)[13] | +/- from 2004 | % change from 2004 |
---|---|---|---|---|---|
1 | Singapore | Singapore | 23,192 | 1,863 | 8.73 |
2 | Hong Kong | People's Republic of China | 22,427 | 443 | 2.02 |
3 | Shanghai | People's Republic of China | 18,084 | 3,527 | 24.23 |
4 | Shenzhen | People's Republic of China | 16,197 | 2,582 | 18.96 |
5 | Busan | South Korea | 11,843 | 413 | 3.61 |
6 | Kaohsiung | Taiwan (Republic of China) | 9,471 | 0 | 0.00 |
7 | Rotterdam | Netherlands | 9,287 | 1,006 | 12.15 |
8 | Hamburg | Germany | 8,088 | 1,085 | 15.49 |
9 | Dubai | United Arab Emirates | 7,619 | 1,190 | 18.51 |
10 | Los Angeles | United States of America | 7,485 | 164 | 2.24 |
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