The Diesel engine, named after Rudolf Diesel, is an internal combustion engine in which ignition of the fuel, injected into the combustion chamber, is caused by the elevated temperature of the air in the cylinder due to the mechanical compression. Diesel engines work by compressing only the air; this increases the air temperature inside the cylinder to such a high degree that atomised Diesel fuel injected into the combustion chamber ignites spontaneously. With the fuel being injected into the air just before combustion, the dispersion of the fuel is uneven; the process of mixing air and fuel happens entirely during combustion, the oxygen diffuses into the flame, which means that the Diesel engine operates with a diffusion flame. The torque a Diesel engine produces is controlled by manipulating the air ratio; the Diesel engine has the highest thermal efficiency of any practical internal or external combustion engine due to its high expansion ratio and inherent lean burn which enables heat dissipation by the excess air.
A small efficiency loss is avoided compared with two-stroke non-direct-injection gasoline engines since unburned fuel is not present at valve overlap and therefore no fuel goes directly from the intake/injection to the exhaust. Low-speed Diesel engines can reach effective efficiencies of up to 55%. Diesel engines may be designed as either four-stroke cycles, they were used as a more efficient replacement for stationary steam engines. Since the 1910s they have been used in ships. Use in locomotives, heavy equipment and electricity generation plants followed later. In the 1930s, they began to be used in a few automobiles. Since the 1970s, the use of Diesel engines in larger on-road and off-road vehicles in the US has increased. According to Konrad Reif, the EU average for Diesel cars accounts for 50% of the total newly registered; the world's largest Diesel engines put in service are 14-cylinder, two-stroke watercraft Diesel engines. In 1878, Rudolf Diesel, a student at the "Polytechnikum" in Munich, attended the lectures of Carl von Linde.
Linde explained that steam engines are capable of converting just 6-10 % of the heat energy into work, but that the Carnot cycle allows conversion of all the heat energy into work by means of isothermal change in condition. According to Diesel, this ignited the idea of creating a machine that could work on the Carnot cycle. After several years of working on his ideas, Diesel published them in 1893 in the essay Theory and Construction of a Rational Heat Motor. Diesel was criticised for his essay, but only few found the mistake that he made. Diesel's idea was to compress the air so that the temperature of the air would exceed that of combustion. However, such an engine could never perform any usable work. In his 1892 US patent #542846 Diesel describes the compression required for his cycle: "pure atmospheric air is compressed, according to curve 1 2, to such a degree that, before ignition or combustion takes place, the highest pressure of the diagram and the highest temperature are obtained-that is to say, the temperature at which the subsequent combustion has to take place, not the burning or igniting point.
To make this more clear, let it be assumed that the subsequent combustion shall take place at a temperature of 700°. In that case the initial pressure must be sixty-four atmospheres, or for 800° centigrade the pressure must be ninety atmospheres, so on. Into the air thus compressed is gradually introduced from the exterior finely divided fuel, which ignites on introduction, since the air is at a temperature far above the igniting-point of the fuel; the characteristic features of the cycle according to my present invention are therefore, increase of pressure and temperature up to the maximum, not by combustion, but prior to combustion by mechanical compression of air, there upon the subsequent performance of work without increase of pressure and temperature by gradual combustion during a prescribed part of the stroke determined by the cut-oil". By June 1893, Diesel had realised his original cycle would not work and he adopted the constant pressure cycle. Diesel describes the cycle in his 1895 patent application.
Notice that there is no longer a mention of compression temperatures exceeding the temperature of combustion. Now it is stated that the compression must be sufficient to trigger ignition. "1. In an internal-combustion engine, the combination of a cylinder and piston constructed and arranged to compress air to a degree producing a temperature above the igniting-point of the fuel, a supply for compressed air or gas. See US patent # 608845 filed 1895 / granted 1898In 1892, Diesel received patents in Germany, the United Kingdom and the United States for "Method of and Apparatus for Converting Heat into Work". In 1894 and 1895, he filed patents and addenda in various
The millimetre or millimeter is a unit of length in the metric system, equal to one thousandth of a metre, the SI base unit of length. Therefore, there are one thousand millimetres in a metre. There are ten millimetres in a centimetre. One millimetre is equal to 1000000 nanometres. A millimetre is equal to 5⁄127 of an inch. Since 1983, the metre has been defined as "the length of the path travelled by light in vacuum during a time interval of 1/299792458 of a second". A millimetre, 1/1000 of a metre, is therefore the distance travelled by light in 1/299792458000 of a second. A common shortening of millimetre in spoken English is "mil"; this can cause confusion since in the United States, "mil" traditionally means a thousandth of an inch. For the purposes of compatibility with Chinese and Korean characters, Unicode has symbols for: millimetre - code U+339C square millimetre - code U+339F cubic millimetre - code U+33A3In Japanese typography, these square symbols were used for laying out unit symbols without distorting the grid layout of text characters.
On a metric ruler, the smallest measurements are millimetres. High-quality engineering rules may be graduated in increments of 0.5 mm. Digital callipers are capable of reading increments as small as 0.01 mm. Microwaves with a frequency of 300 GHz have a wavelength of 1 mm. Using wavelengths between 30 GHz and 300 GHz for data transmission, in contrast to the 300 MHz to 3 GHz used in mobile devices, has the potential to allow data transfer rates of 10 gigabits per second; the smallest distances the human eye can resolve is around 0.02 to 0.04 mm the width of a human hair. A sheet of paper is between 0.07 mm and 0.18 mm thick, with ordinary printer paper or copy paper a tenth of a millimetre thick. Metric system Orders of magnitude Submillimeter
MAN SE MAN AG, is a German mechanical engineering company and parent company of the MAN Group. It is a subsidiary of automaker Volkswagen AG. MAN SE is based in Munich, its primary output is for the automotive industry heavy trucks. Further activities include the production of diesel engines for various applications, like marine propulsion, turbomachinery. MAN supplies trucks, diesel engines and turbomachinery. In 2016, its 53,824 employees generated annual sales of around €13.6 billion. MAN SE is owned in majority by Volkswagen AG, it is a producer of Commercial Vehicles, through its MAN Truck & Bus and MAN Latin America divisions, participation in the manufacturer Sinotruk. MAN traces its origins back to 1758, when the "St. Antony" ironworks commenced operation in Oberhausen, as the first heavy-industry enterprise in the Ruhr region. In 1808, the three ironworks "St. Antony", "Gute Hoffnung", "Neue Essen" merged, to form the Hüttengewerkschaft und Handlung Jacobi, renamed Gute Hoffnungshütte. In 1840, the German engineer Ludwig Sander founded in Augsburg the first predecessing enterprise of MAN in Southern Germany: the "Sander'sche Maschinenfabrik."
It firstly became the "C. Reichenbach'sche Maschinenfabrik", named after the pioneer of printing machines Carl August Reichenbach, on the "Maschinenfabrik Augsburg"; the branch Süddeutsche Brückenbau A. G. was founded when the company in 1859 was awarded the contract for the construction of the railway bridge over the Rhine at Mainz. In 1898, the companies Maschinenbau-AG Nürnberg and Maschinenfabrik Augsburg AG merged to form Vereinigte Maschinenfabrik Augsburg und Maschinenbaugesellschaft Nürnberg A. G. Augsburg. In 1908, the company was renamed Maschinenfabrik Augsburg Nürnberg AG, or in short, M·A·N. While the focus remained on ore mining and iron production in the Ruhr region, mechanical engineering became the dominating branch of business in Augsburg and Nuremberg. Under the direction of Heinrich von Buz, Maschinenfabrik Augsburg grew from a medium-sized business of 400 employees into a major enterprise with a workforce of 12,000 by the year 1913. Locomotion and steel building were the big topics of this phase.
The early predecessors of MAN were responsible for numerous technological innovations. The success of the early MAN entrepreneurs and engineers like Heinrich Gottfried Gerber, was based on a great openness towards new technologies, they constructed the Wuppertal monorail and the first spectacular steel bridges like the Großhesseloher Brücke in Munich in 1857 and the Müngsten railway bridge between 1893 and 1897. The invention of the rotary printing press allowed the copious printing of books and newspapers and since 1893, Rudolf Diesel puzzled for four years with future MAN engineers in a laboratory in Augsburg until his first Diesel engine was completed and functional. During 1921, the majority of M. A. N. was taken over by Sterkrade. Through well-directed equities and acquisitions of processing industries, e.g. Deutsche Werft, Deggendorfer Werft und Eisenbau, MAN advanced to a nationwide operating enterprise, with a workforce of 52,000 by 1921. MAN produced tractors by the name MAN Ackerdiesel between.
The decision for tractors production was made due to increasing demand from eastern Germany. At the same time the GHH's economic situation worsened; the causes for this were, among others, the reparations after World War I, the occupation of the Ruhr region and the world economic crisis. In only two years the number of MAN employees sank from 14,000 in the year 1929/30 to 7,400 in 1931/32. While the civil business was collapsing, the military business increased with the armament under the National Socialist regime. GHH/MAN enterprises supplied diesel engines for submarines, cylinders for projectiles and artillery of every description. MAN produced gun parts, including Mauser Karabiner 98k rifle bolts, their Waffenamt code was WaA53, ordnance code was "coc". The MAN works in Augsburg, which produced diesel engines for U-boats, the MAN works in Nuremberg, which built 40 percent of Germany's Panther tanks, were the target of massive Allied bombing attacks during World War II. After the end of World War II the allies split up the GHH group.
A vertical integration in which mining and steel production are consolidated was not allowed any more. The "Gutehoffnungshütte", together with the MAN firms of Southern Germany, therefore concentrated on engineering, plant construction, commercial vehicles and printing machines; this process has been supported by strategic dispositions. In 1982/83 the "Gutehoffnungshütte" plunged into a deep corporate crisis; the enterprise suffered from the late effects of a bad economic situation. This was displayed by the dramatic downturn of the commercial vehicles sales figures. Besides e
Marine propulsion is the mechanism or system used to generate thrust to move a ship or boat across water. While paddles and sails are still used on some smaller boats, most modern ships are propelled by mechanical systems consisting of an electric motor or engine turning a propeller, or less in pump-jets, an impeller. Marine engineering is the discipline concerned with the engineering design process of marine propulsion systems. Manpower, in the form of paddles, sail were the first forms of marine propulsion. Rowed galleys, some equipped with sail played an important early role; the first advanced mechanical means of marine propulsion was the marine steam engine, introduced in the early 19th century. During the 20th century it was replaced by two-stroke or four-stroke diesel engines, outboard motors, gas turbine engines on faster ships. Marine nuclear reactors, which appeared in the 1950s, produce steam to propel warships and icebreakers. Electric motors using electric battery storage have been used for propulsion on submarines and electric boats and have been proposed for energy-efficient propulsion.
Development in liquefied natural gas fueled engines are gaining recognition for their low emissions and cost advantages. Stirling engines, which are more efficient, smoother running producing less harmful emissions than diesel engines, propel a number of small submarines, its design has yet to be upscaled for larger surface ships. Until the application of the coal-fired steam engine to ships in the early 19th century, oars or the wind were the principal means of watercraft propulsion. Merchant ships predominantly used sail, but during periods when naval warfare depended on ships closing to ram or to fight hand-to-hand, galley were preferred for their manoeuvrability and speed; the Greek navies that fought in the Peloponnesian War used triremes, as did the Romans at the Battle of Actium. The development of naval gunnery from the 16th century onward vaulted broadside weight ahead of manoeuvrability. In modern times, human propulsion is found on small boats or as auxiliary propulsion on sailboats.
Human propulsion includes the push pole and pedals. Propulsion by sail consists of a sail hoisted on an erect mast, supported by stays, controlled by lines made of rope. Sails were the dominant form of commercial propulsion until the late nineteenth century, continued to be used well into the twentieth century on routes where wind was assured and coal was not available, such as in the South American nitrate trade. Sails are now used for recreation and racing, although innovative applications of kites/royals, rotorsails, wingsails and SkySails's own kite buoy-system have been used on larger modern vessels for fuel savings; the development of piston-engined steamships was a complex process. Early steamships were fueled by wood ones by coal or fuel oil. Early ships used stern or side paddle wheels; the first commercial success accrued to Robert Fulton's North River Steamboat in US in 1807, followed in Europe by the 45-foot Comet of 1812. Steam propulsion progressed over the rest of the 19th century.
Notable developments include the steam surface condenser, which eliminated the use of sea water in the ship's boilers. This, along with improvements in boiler technology, permitted higher steam pressures, thus the use of higher efficiency multiple expansion engines; as the means of transmitting the engine's power, paddle wheels gave way to more efficient screw propellers. Multiple expansion steam engines became widespread in the late 19th century; these engines exhausted steam from a high pressure cylinder to a lower pressure cylinder, giving a large increase in efficiency. Steam turbines were fueled by coal or fuel oil or nuclear power; the marine steam turbine developed by Sir Charles Algernon Parsons raised the power-to-weight ratio. He achieved publicity by demonstrating it unofficially in the 100-foot Turbinia at the Spithead Naval Review in 1897; this facilitated a generation of high-speed liners in the first half of the 20th century, rendered the reciprocating steam engine obsolete. In the early 20th century, heavy fuel oil came into more general use and began to replace coal as the fuel of choice in steamships.
Its great advantages were convenience, reduced manpower by removal of the need for trimmers and stokers, reduced space needed for fuel bunkers. In the second half of the 20th century, rising fuel costs led to the demise of the steam turbine. Most new ships since around 1960 have been built with diesel engines; the last major passenger ship built with steam turbines was Fairsky, launched in 1984. Many steam ships were re-engined to improve fuel efficiency. One high-profile example was the 1968 built Queen Elizabeth 2 which had her steam turbines replaced with a diesel-electric propulsion plant in 1986. Most new-build ships with steam turbines are specialist vessels such as nuclear-powered vessels, certain merchant vessels where the cargo can be used as bunker fuel. New LNG carriers continue to be built with steam turbines; the natural gas is stored in a liquid state in cryogenic vessels aboard these ships, a small amount of'boil off' gas is needed to maintain the pressure and temperature inside the vessels within operating limits.
The'boil off' gas provides the fuel for the ship's boilers, which provide steam for the tu
The inch is a unit of length in the imperial and United States customary systems of measurement. It is equal to 1⁄12 of a foot. Derived from the Roman uncia, the word inch is sometimes used to translate similar units in other measurement systems understood as deriving from the width of the human thumb. Standards for the exact length of an inch have varied in the past, but since the adoption of the international yard during the 1950s and 1960s it has been based on the metric system and defined as 25.4 mm. The English word "inch" was an early borrowing from Latin uncia not present in other Germanic languages; the vowel change from Latin /u/ to Old English /y/ is known as umlaut. The consonant change from the Latin /k/ to English /tʃ/ is palatalisation. Both were features of Old English phonology. "Inch" is cognate with "ounce", whose separate pronunciation and spelling reflect its reborrowing in Middle English from Anglo-Norman unce and ounce. In many other European languages, the word for "inch" is the same as or derived from the word for "thumb", as a man's thumb is about an inch wide.
Examples include Afrikaans: duim. The inch is a used customary unit of length in the United States and the United Kingdom, it is used in Japan for electronic parts display screens. In most of continental Europe, the inch is used informally as a measure for display screens. For the United Kingdom, guidance on public sector use states that, since 1 October 1995, without time limit, the inch is to be used as a primary unit for road signs and related measurements of distance and may continue to be used as a secondary or supplementary indication following a metric measurement for other purposes; the international standard symbol for inch is in but traditionally the inch is denoted by a double prime, approximated by double quotes, the foot by a prime, approximated by an apostrophe. For example, three feet two inches can be written as 3′ 2″. Subdivisions of an inch are written using dyadic fractions with odd number numerators. 1 international inch is equal to: 10,000 tenths 1,000 thou or mil 100 points or gries 72 PostScript points 10, 12, 16, or 40 lines 6 computer picas 3 barleycorns 25.4 millimetres 0.999998 US Survey inches 1/3 or 0.333 palms 1/4 or 0.25 hands 1/12 or 0.08333 feet 1/36 or 0.02777 yards The earliest known reference to the inch in England is from the Laws of Æthelberht dating to the early 7th century, surviving in a single manuscript, the Textus Roffensis from 1120.
Paragraph LXVII sets out the fine for wounds of various depths: one inch, one shilling, two inches, two shillings, etc. An Anglo-Saxon unit of length was the barleycorn. After 1066, 1 inch was equal to 3 barleycorns, which continued to be its legal definition for several centuries, with the barleycorn being the base unit. One of the earliest such definitions is that of 1324, where the legal definition of the inch was set out in a statute of Edward II of England, defining it as "three grains of barley and round, placed end to end, lengthwise". Similar definitions are recorded in both Welsh medieval law tracts. One, dating from the first half of the 10th century, is contained in the Laws of Hywel Dda which superseded those of Dyfnwal, an earlier definition of the inch in Wales. Both definitions, as recorded in Ancient Laws and Institutes of Wales, are that "three lengths of a barleycorn is the inch". King David I of Scotland in his Assize of Weights and Measures is said to have defined the Scottish inch as the width of an average man's thumb at the base of the nail including the requirement to calculate the average of a small, a medium, a large man's measures.
However, the oldest surviving manuscripts date from the early 14th century and appear to have been altered with the inclusion of newer material. In 1814, Charles Butler, a mathematics teacher at Cheam School, recorded the old legal definition of the inch to be "three grains of sound ripe barley being taken out the middle of the ear, well dried, laid end to end in a row", placed the barleycorn, not the inch, as the base unit of the English Long Measure system, from which all other units were derived. John Bouvier recorded in his 1843 law dictionary that the barleycorn was the fundamental measure. Butler observed, that "s the length of the barley-corn cannot be fixed, so the inch according to this method will be uncertain", noting that a standard inch measure was now kept in the Exchequer chamber and, the legal definition of the inch; this was a point made by George Long in his 1842 Penny Cyclopædia, observing that st
Germany the Federal Republic of Germany, is a country in Central and Western Europe, lying between the Baltic and North Seas to the north, the Alps to the south. It borders Denmark to the north and the Czech Republic to the east and Switzerland to the south, France to the southwest, Luxembourg and the Netherlands to the west. Germany includes 16 constituent states, covers an area of 357,386 square kilometres, has a temperate seasonal climate. With 83 million inhabitants, it is the second most populous state of Europe after Russia, the most populous state lying in Europe, as well as the most populous member state of the European Union. Germany is a decentralized country, its capital and largest metropolis is Berlin, while Frankfurt serves as its financial capital and has the country's busiest airport. Germany's largest urban area is the Ruhr, with its main centres of Essen; the country's other major cities are Hamburg, Cologne, Stuttgart, Düsseldorf, Dresden, Bremen and Nuremberg. Various Germanic tribes have inhabited the northern parts of modern Germany since classical antiquity.
A region named Germania was documented before 100 AD. During the Migration Period, the Germanic tribes expanded southward. Beginning in the 10th century, German territories formed a central part of the Holy Roman Empire. During the 16th century, northern German regions became the centre of the Protestant Reformation. After the collapse of the Holy Roman Empire, the German Confederation was formed in 1815; the German revolutions of 1848–49 resulted in the Frankfurt Parliament establishing major democratic rights. In 1871, Germany became a nation state when most of the German states unified into the Prussian-dominated German Empire. After World War I and the revolution of 1918–19, the Empire was replaced by the parliamentary Weimar Republic; the Nazi seizure of power in 1933 led to the establishment of a dictatorship, the annexation of Austria, World War II, the Holocaust. After the end of World War II in Europe and a period of Allied occupation, Austria was re-established as an independent country and two new German states were founded: West Germany, formed from the American and French occupation zones, East Germany, formed from the Soviet occupation zone.
Following the Revolutions of 1989 that ended communist rule in Central and Eastern Europe, the country was reunified on 3 October 1990. Today, the sovereign state of Germany is a federal parliamentary republic led by a chancellor, it is a great power with a strong economy. As a global leader in several industrial and technological sectors, it is both the world's third-largest exporter and importer of goods; as a developed country with a high standard of living, it upholds a social security and universal health care system, environmental protection, a tuition-free university education. The Federal Republic of Germany was a founding member of the European Economic Community in 1957 and the European Union in 1993, it is part of the Schengen Area and became a co-founder of the Eurozone in 1999. Germany is a member of the United Nations, NATO, the G7, the G20, the OECD. Known for its rich cultural history, Germany has been continuously the home of influential and successful artists, musicians, film people, entrepreneurs, scientists and inventors.
Germany has a large number of World Heritage sites and is among the top tourism destinations in the world. The English word Germany derives from the Latin Germania, which came into use after Julius Caesar adopted it for the peoples east of the Rhine; the German term Deutschland diutisciu land is derived from deutsch, descended from Old High German diutisc "popular" used to distinguish the language of the common people from Latin and its Romance descendants. This in turn descends from Proto-Germanic *þiudiskaz "popular", derived from *þeudō, descended from Proto-Indo-European *tewtéh₂- "people", from which the word Teutons originates; the discovery of the Mauer 1 mandible shows that ancient humans were present in Germany at least 600,000 years ago. The oldest complete hunting weapons found anywhere in the world were discovered in a coal mine in Schöningen between 1994 and 1998 where eight 380,000-year-old wooden javelins of 1.82 to 2.25 m length were unearthed. The Neander Valley was the location where the first non-modern human fossil was discovered.
The Neanderthal 1 fossils are known to be 40,000 years old. Evidence of modern humans dated, has been found in caves in the Swabian Jura near Ulm; the finds included 42,000-year-old bird bone and mammoth ivory flutes which are the oldest musical instruments found, the 40,000-year-old Ice Age Lion Man, the oldest uncontested figurative art discovered, the 35,000-year-old Venus of Hohle Fels, the oldest uncontested human figurative art discovered. The Nebra sky disk is a bronze artefact created during the European Bronze Age attributed to a site near Nebra, Saxony-Anhalt, it is part of UNESCO's Memory of the World Programme. The Germanic tribes are thought to date from the Pre-Roman Iron Age. From southern Scandinavia and north Germany, they expanded south and west from the 1st century BC, coming into contact with the Celtic tribes of Gaul as well
Container ships are cargo ships that carry all of their load in truck-size intermodal containers, in a technique called containerization. They 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. Typical loads are a mix of 40-foot ISO-standard containers, with the latter predominant. Today, about 90% of non-bulk cargo worldwide is transported by container ships, the largest modern container ships can carry over 21,000 TEU. Container ships now rival crude oil tankers and bulk carriers as the largest commercial seaborne vessels. There are two main types of dry cargo: bulk break bulk cargo. Bulk cargoes, like grain or coal, are transported unpackaged in the hull of the ship in large volume. Break-bulk cargoes, on the other hand, are transported in packages, are manufactured goods. Before the advent of containerization in the 1950s, break-bulk items were loaded, lashed and unloaded from the ship one piece at a time.
However, by grouping cargo into containers, 1,000 to 3,000 cubic feet of cargo, or up to about 64,000 pounds, is moved at once and each container is secured to the ship once in a standardized way. Containerization has increased the efficiency of moving traditional break-bulk cargoes reducing shipping time by 84% and costs by 35%. In 2001, more than 90% of world trade in non-bulk goods was transported in ISO containers. In 2009 one quarter of the world's dry cargo was shipped by container, an estimated 125 million TEU or 1.19 billion metric tons worth of cargo. The first ships designed to carrying 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 by Bridgewater Canal. Before the Second World War first container ships were used to carrying baggages of the luxury passenger train from London to Paris, Golden Arrow / Flèche d'Or, in 1926 by Southern Railway.
These containers were loaded in London or Paris and carried to ports, Dover or Calais, on flat cars in the UK and "CIWL Pullman Golden Arrow Fourgon of CIWL" in France. 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, between Seattle and Alaska; the first commercially successful container ship was Ideal X, a T2 tanker, owned by Malcom McLean, which carried 58 metal containers between Newark, New Jersey and Houston, Texas, on its first voyage. In 1955, McLean built his company, McLean Trucking into one of 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. 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.
MV Kooringa was the world's first cellular purpose-built container ship and was built by Australian company, Associated Steamships Pty. Ltd. in partnership with McIlwraith, McEacharn & Co and commissioned in May 1964. Container vessels eliminate the individual hatches and dividers of the traditional general cargo vessels; the hull of a typical container ship is a huge warehouse divided into cells by vertical guide rails. These cells are designed to hold cargo in pre-packed units – containers. Shipping containers are made of steel, but other materials like aluminum, fiberglass or plywood are used, they are designed to be transferred to and from smaller coastal carriers, trucks or semi-trailers. There are several types of containers and they are categorized according to their size and functions. Today, about 90% of non-bulk cargo worldwide is transported by container, modern container ships can carry over 21,000 TEU; as a class, container ships now rival crude oil tankers and bulk carriers as the largest commercial vessels on the ocean.
Although containerization caused a revolution in the world of shipping, its introduction did not have an easy passage. Ports, railway companies, shippers were concerned about the huge costs of developing the ports and railway infrastructure needed to handle container ships, for the movement of containers on land by rail and road. Trade unions were concerned about massive job loss among port and dock workers at ports, as containers were sure to eliminate several manual jobs of cargo handling at ports, it took ten years of legal battles before container ships would be pressed into international service. In 1966, a container liner service from the US to the Dutch city of Rotterdam commenced. Containerization changed not only the face of shipping, but it revolutionized world trade as well. A container ship can be loaded and unloaded in a few hours compared to days in a traditional cargo vessel. This, besides cutting labor costs, has reduced shipping times between ports to a great extent, it has resulted in less breakage due to less handling.
As containers are sealed and only opened at the destination and theft levels have been reduced. Containerization has lowered shipping expense and decreased shipping time, this has in turn help