The Knock Nevis, formerly the world's largest ship, has been converted to an oil storage terminal. History Knock Nevis was built in 1979 at Sumitomo Heavy Industries 's Oppama Shipyard as Seawise Giant. |
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| Class overview | |
|---|---|
| Name: | Oil tanker |
| Subclasses: | Handymax, Handysize, Panamax, Capesize |
| Built: | c. Handymax or Supramax is a Naval architecture term for a Bulk carrier, typically between 35000 and. Although there is no official definition in terms of exact tonnages Handysize most usually refers to a dry bulk vessel (or less commonly to a product tanker " Panamax " ships are of the maximum dimensions that will fit through the locks of the Panama Canal. Capesize ships are Cargo ships originally too large to transit the Suez Canal (i 1863 – present |
| In service: | 4,024 (above 10,000 long tons of deadweight (DWT)). Deadweight tonnage (also known as deadweight and variously abbreviated as DWT, D [1] |
| General characteristics | |
| Type: | Cargo ship |
| Capacity: | up to 550,000 DWT |
| Notes: | Rear house, full hull, midships pipeline |
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Oil tankers, also known as petroleum tankers, are ships designed for the bulk transport of oil. A cargo ship or freighter is any sort of Ship or vessel that carries Cargo, goods and materials from one port to another A merchant vessel is a Ship that transports Cargo and Passengers during peace time An oil is a substance that is in a viscous Liquid state ( "oily") at ambient temperatures or slightly warmer and is There are two basic types of oil tanker: the crude tanker and the product tanker. [2] Crude tankers move large quantities of unrefined crude oil from its point of extraction to refineries. Petroleum ( L petroleum, from Greek πετρέλαιον, lit [2] Product tankers, generally much smaller, are designed to move petrochemicals from refineries to points near consuming markets. Petrochemicals are chemical products made from raw materials of Petroleum or other Hydrocarbon origin
Oil tankers are often classified by their size as well as their occupation. The size classes range from inland or coastal tankers of a few thousand long tons of deadweight (DWT) to the mammoth supertankers of 550,000 DWT.
Tankers move approximately 2 billion tons of oil every year. [3] Second only to pipelines in terms of efficiency,[3] the cost of tanker transport amounts to only two or three U. S. cents per gallon. [3]
Some specialized types of oil tankers have evolved. One of these is the naval oiler, a tanker which can fuel a moving vessel. refueling USS Badger (DE-1071 April 1975]] Underway replenishment (UNREP (US Navy or replenishment at sea (RAS (Royal Navy is a method of transferring fuel munitions Combination ore-bulk-oil carriers and permanently moored floating storage units are two other variations on the standard oil tanker design. An Ore-bulk-oil carrier, also known as combination carrier or OBO, is a Ship designed to be capable of carrying wet or dry Cargoes The idea is
Oil tankers have been involved in a number of damaging and high-profile oil spills. For the fictional character see Oil Slick (Transformers. An oil spill is the release of a Liquid Petroleum Hydrocarbon into As a result, they are subject to stringent design and operational regulations.
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The technology of oil transportation has evolved alongside the oil industry. Although man's use of oil reaches to prehistory, the first modern commercial exploitation dates back to James Young's manufacture of parafin in 1850. James Young ( 13 July, 1811 &ndash May 13, 1883) was a Scottish chemist best known for his method of distilling Paraffin [5] In these early days, oil from Upper Burma was moved in earthenware vessels to the river bank where it was then poured into boat holds. Upper Burma was a term used by the British to refer to the central and northern area of what is now the country of Myanmar (Burma [6] In the 1850s, the Pennsylvania oil fields became a major supplier of oil, and a center of innovation. The Commonwealth of Pennsylvania ( often colloquially referred to as PA (its abbreviation by natives and Northeasterners is a state located in the Northeastern [6]
Break-bulk boats and barges were originally used to transport Pennsylvania oil in 40-gallon wooden barrels. [6] But transport by barrel had several problems. The first problem was weight: the standard empty barrel weighed 64 pounds, representing 20% of the total weight of a full barrel. [7] Also, barrels were leaky, and could only be carried one way. [7] Finally, barrels were themselves expensive. For example, in the early years of the Russian oil industry, barrels accounted for half the cost of petroleum production. [7]
The movement of oil in bulk was attempted in many places and in many ways. Modern oil pipelines have existed since 1860. [6] In 1863, two sail-driven tankers were built on England's River Tyne. The River Tyne is a River in England. It is formed by the confluence of two rivers the North Tyne and the South Tyne. [8] These were followed by the first oil-tank steamer, the Vaderland, which was purchased by Palmers Shipbuilding and Iron Company. Palmers Shipbuilding and Iron Company Limited, often referred to simply as Palmers, was a British shipbuilding company established in 1852 by Charles [8] By 1871, the Pennsylvania oil fields were making limited use of oil tank barges and cylindrical railroad tank-cars similar to those in use today. [6]
Ludvig Nobel, brother of Alfred Nobel, was a pioneer in the development of early oil tankers. Ludvig Nobel (1831-1888 was an engineering genius a noted businessman and a humanitarian (21 October 1833 Stockholm, Sweden – 10 December 1896 Sanremo, Italy) was a Swedish chemist engineer innovator armaments manufacturer He first experimented with carrying oil in bulk on single-hulled barges. [7] Turning his attention to self-propelled tankships, he faced a number of challenges. A primary concern was to keep the cargo and fumes well away from the engine room to avoid fires. [9] Other challenges included allowing for the cargo to expand and contract due to temperature changes, and providing a method to ventilate the tanks. [9]
The world's first successful oil tanker was Nobel's Zoroaster. He designed this ship in Lindholmen-Motala in Sweden with Sven Almqvist. "Sverige" redirects here For other uses see Sweden (disambiguation and Sverige (disambiguation. [9] The contract to build it was signed in January 1878, and it made its first run later that year from Baku to Astrakhan. Baku (Bakı sometimes known as Baqy, Baky, Baki or Bakü, is the capital the largest city and the largest port of Azerbaijan Astrakhan (А́страхань Ästerxan Persian: حاجیترخان Haji-Tarkhan) is a major city in southern European Russia and [9] The Zoroaster design was widely studied and copied, with Nobel refusing to patent any part of it. [9] In October 1878, he ordered two more tankers of the same design: the Buddha and the Nordenskjöld. [9]
Zoraster carried its 242 tons of kerosene cargo in two iron tanks joined by pipes. [9] One tank was forward of the midships engineroom and the other was aft. [9] The ship also featured a set of 21 vertical watertight compartments for extra buoyancy. In Physics, buoyancy ( BrE IPA: /ˈbɔɪənsi/ is the upward Force on an object produced by the surrounding liquid or gas in which it is [9] The ship had a length overall of 184 feet (56 m), a beam of 27 feet (8. 2 m), and a draft of 9 feet (2. 7 m). [9] Unlike later Nobel tankers, the Zoraster design was built small enough to sail from Sweden to the Caspian by way of the Baltic Sea, Lake Ladoga, Lake Onega, the Rybinsk and Mariinsk Canals and the Volga River. "Sverige" redirects here For other uses see Sweden (disambiguation and Sverige (disambiguation. Consumers Against Supermarket Privacy Invasion and Numbering ( CASPIAN) is a USA Grass-roots Consumer group dedicated to fighting Supermarket "loyalty" The Baltic Sea is a Brackish inland sea located in Northern Europe, from 53°N to 66°N Latitude and from 20°E to 26°E Longitude. Lake Ladoga (Лáдожское Óзеро Ladozhskoye Ozero; Laatokka is a Freshwater Lake located in Republic of Karelia and Leningrad Lake Onega (also known as Onego, Онежское озеро Onezhskoe ozero, i Rybinsk (Ры́бинск is the second largest city of Yaroslavl Oblast, Russia The Volga-Baltic Waterway, formerly known as the Mariinsk Canal System (Russian Мариинская водная система is a series of Canals and Rivers [9]
Nobel then began to adopt a single-hull design, where the ship's hull forms part of its tank structure. [9] In November 1880, he ordered his first single-hulled tanker, the Moses. [9] Within a year, he ordered seven more single-hulled tankers: the Mohammed, Tatarin, Bramah, Spinoza, Socrates, Darwin, Koran, Talmud, and Calmuck. [9]
The Nobel company experienced one of the first oil tanker disasters. In 1881, the Zoroaster's sister-ship, the Nordenskjöld exploded in Baku while taking on kerosene. [9] The pipe carrying the cargo was jerked away from the hold when the ship was hit by a gust of wind. [9] Kerosene then spilled onto the deck and down into the engineroom, where mechanics were working in the light of kerosene lanterns. [9] The ship then exploded, killing half the crew. [9] Nobel responded to the disaster by creating a flexible, leakproof loading pipe which was much more resistant to spills. [10]
In 1883, oil tanker design took a large step forward. Working for the Nobel company, Colonel Henry F. Swan designed a set of three Nobel tankers. [11] Instead of one or two large holds, Swan's design used several holds which spanned the width, or beam, of the ship. [11] These holds were further subdivided into port and starboard sections by a longitudinal bulkhead. [11] Earlier designs suffered from stability problems caused by the free surface effect, where oil sloshing from side to side could cause a ship to capsize. The free surface effect is one of several mechanisms where a craft can become unstable and roll-over ( Capsize) [12] But this approach of dividing the ship's storage space into smaller tanks virtually eliminated free-surface problems. [12] This approach, almost universal today, was first used by Swan in the Nobel tankers Blesk, Lumen, and Lux. [11][13]
In 1903, the Nobel brothers built two oil tankers which ran on internal combustion engines, as opposed to the older steam engines. The internal combustion engine is an engine in which the Combustion of Fuel and an Oxidizer (typically air occurs in a confined space called a A steam engine is a Heat engine that performs Mechanical work using Steam as its Working fluid. [8] The Vandale and Sarmat were each capable of carrying 750 tons of refined oil and powered by 360 horsepower (270 kW) diesel motors. [14] This same firm soon went on to make much larger oil tankers, such as the Emanuel Nobel and Karl Hagelin, 4,600-ton kerosene tankers with 1,200 horsepower (890 kW) engines. [15]
The fleet oiler USS Maumee, launched on April 17, 1915, pioneered the technique of underway replenishment. Early career Prior to the entry of the United States into World War I, Maumee operated off the east coast and Cuba. Events 69 - After the First Battle of Bedriacum, Vitellius becomes Roman Emperor. Year 1915 ( MCMXV) was a Common year starting on Friday (link will display the full calendar of the Gregorian calendar (or a Common year refueling USS Badger (DE-1071 April 1975]] Underway replenishment (UNREP (US Navy or replenishment at sea (RAS (Royal Navy is a method of transferring fuel munitions [16] A large ship at the time, at 14,500 deadweight tons, Maumee began refuelling destroyers en route to Britain at the outset of World War I. In naval terminology a destroyer is a fast and maneuverable yet long-endurance Warship intended to escort larger vessels in a fleet, Convoy World War I (abbreviated WWI; also known as the First World War, the Great War, and the War to End All [16] This technique enabled the Navy to keep its fleets at sea for extended periods, with a far greater range independent of the availability of a friendly port. [16] This independence proved crucial to victory in World War II by the ships commanded by Fleet Admiral Nimitz who, as Maumee’s executive officer, had played a key role in developing underway replenishment. Fleet Admiral Chester William Nimitz, USN, GCB ( February 24, 1885 &ndash February 20, 1966) held the dual command While executive officer literally refers to a person responsible for the performance of duties involved in running an Organization, the exact meaning of the role is variable [16]
Underway replenishment was quickly adopted by other navies. One example of this is the Australian fleet oiler HMAS Kurumba which provided underway replenishment services in the United Kingdom's Royal Navy from 1917 to 1919. The Royal Navy of the United Kingdom is the oldest of the British armed services (and is therefore known as the Senior Service) [17]
Oil tankers, particularly the T-2 tanker, played an important part in World War II. The T2 tanker, or T2, was an oil tanker constructed and produced in large quantities in the United States during World War II. World War II, or the Second World War, (often abbreviated WWII) was a global military conflict which involved a majority of the world's nations, including The 16,613 DWT T2-SE-A1 was the most popular variant, with nearly 500 built during the war. [18] After the war, these tankers were used commercially for decades, and many were sold on the international market. [18]
Until 1956, tankers were designed to be able to navigate the Suez Canal. The Suez Canal is a Canal in Egypt. Opened in 1869 it allows Water transportation between Europe and Asia without circumnavigation [18] This size restriction became much less of a priority after the closing of the canal during the Suez Crisis of 1956. The Suez Crisis, also referred to as the Tripartite Aggression, (أزمة السويس - العدوان الثلاثي Crise du canal de Suez מבצע קדש Kadesh [18] Forced to move oil around the Cape of Good Hope, shipowners realized that bigger tankers were the key to more efficient transport. The Cape of Good Hope ( Afrikaans: Kaap die Goeie Hoop, Kaap de Goede Hoop Cabo da Boa Esperança Persian Language: دماغه امید نیک [18]
Tankers have grown significantly in size since World War II. [19] A typical T-2 tanker of the World War II era was 532 feet (162 m) long and had a capacity of 16,500 DWT. The T2 tanker, or T2, was an oil tanker constructed and produced in large quantities in the United States during World War II. [20] A modern ultra-large crude carrier (ULCC) can be 1,300 feet (400 m) long and have a capacity of 500,000 DWT. [20] Several factors encouraged this growth. Hostilities in the Middle East which interrupted traffic through the Suez Canal contributed, as did nationalization of Middle East oil refineries. The Middle East is a Subcontinent with no clear boundaries often used as a synonym to Near East, in opposition to Far East. The Suez Canal is a Canal in Egypt. Opened in 1869 it allows Water transportation between Europe and Asia without circumnavigation An oil refinery is an industrial Process plant where Crude oil is processed and refined into more useful Petroleum products, such as Gasoline [19] Fierce competition among shipowners also played a part. [19] But apart from these considerations is a simple economic advantage: the larger an oil tanker is, the more cheaply it can move crude oil, and the better it can help meet growing demands for oil. [19]
In 1958, U. S. shipping magnate Daniel K. Ludwig broke the barrier of 100,000 long tons of heavy displacement. Daniel K Ludwig ( June 24 1897, South Haven Michigan - August 27 1992) was a US shipping magnate and Billionaire. [21] His Universe Apollo displaced 104,500 long tons, a 23% increase from the previous record-holder, Universe Leader which also belonged to Ludwig. [21][22]
The world's largest supertanker ever was built in 1979 at as the Oppama Shipyard of Sumitomo Heavy Industries, Ltd. as the Seawise Giant. This ship was built with a capacity of 564,763 DWT, a length overall of 458. Length overall, often abbreviated as ( LOA, o/a, oa or oa) refers to the maximum length of a vessel from the two points on the hull most distant 45 metres (1,504. 1 ft) and a draft of 24. 611 metres (80. 74 ft). [23] She has 46 tanks, 31,541 square metres (339,500 sq ft) of deck, and is too large to pass through the English Channel. [24]
Seawise Giant was renamed Happy Giant in 1989, Jahre Viking in 1991. [23] From 1979 to 2004, she was owned by Loki Stream AS, at which point she was bought by First Olsen Tankers Pte. Ltd. , renamed Knock Nevis and converted into a permanently moored storage tanker. History Knock Nevis was built in 1979 at Sumitomo Heavy Industries 's Oppama Shipyard as Seawise Giant. [23][24]
As of 2008, the worlds four largest working supertankers are the sister ships currently known as the TI Asia, TI Europe, TI Oceania, and TI Africa. [25][26] These ships were built in 2002 and 2003 as the Hellespont Alhambra, Hellespont Metropolis, Hellespont Tara and Fairfax for the Greek Hellespont Steamship Corporation. [27] Hellespont sold these ships to Overseas Shipholding Group and Euronav NV in 2004. Overseas Shipholding Group Inc ( OSG) is the second largest oil tanker company in the world } Euronav is one of the world's leading independent tanker companies engaged in the ocean transportation of Crude oil and Petroleum products [28]
Each of the four sister ships has a capacity of over 441500 DWT, a length overall of 308. 0 metres (1,010 ft) and a cargo capacity of 3,166,353 barrels (503,409,900 l). [29] The first ULCC tankers to be built for some 25 years, they were also the first ULCCs to be double-hulled. [27] To differentiate them from smaller ULCCs, these ships are sometimes given the V-Plus size designation. [30][29] In February 2008, their owners announced plans to convert TI Africa and the TI Asia into stationary Floating Storage and Offloading units to be placed in the Al Shaheen oilfield near Qatar in late 2009. Qatar ( قطر; ˈqɑtˁɑr local pronunciation giṭar officially the State of Qatar (Arabic دولة قطر transliterated [25]
With the exception of the pipeline, the tanker is the most cost-effective way to move oil today. [31] Worldwide, tankers carry some 2,000,000,000 barrels (320,000,000,000 l) annually, and the cost of transportation by tanker amounts to only US$0. 02 per gallon at the pump. [31]
| Oil tanker size categories | |||||
| Name | Size in DWT |
New price[32] |
Used price[33] |
||
|---|---|---|---|---|---|
| Seawaymax | 10,000-60,000[34] | $43M | $42. term Seawaymax refers to vessels which are the maximum size that can fit through the Canal locks of the St 5M | ||
| Panamax | 55,000-80,000[35] | ||||
| Aframax | 80,000-120,000[36] | $58M | $60. " Panamax " ships are of the maximum dimensions that will fit through the locks of the Panama Canal. An Aframax ship is an oil tanker with capacity between and. Aframax class tankers are largely used in the basins of the Black Sea, the North Sea, the 7M | ||
| Suezmax | 120,000-200,000[37] | ||||
| VLCC | 150,000-300,000[38] | $120M | $116M | ||
| ULCC | over 300,000[38] | ||||
| V Plus | over 440,000 | ||||
Merchant oil tankers carry a wide range of hydrocarbon liquids ranging from crude oil to refined petroleum products. Suezmax is a Naval architecture term for the largest ships capable of transiting the Suez Canal fully loaded and is almost exclusively used in reference to [2] Their size is measured in deadweight tons (DWT). Tonnage is a measure of the size or Cargo capacity of a Ship. Crude carriers are among the largest, ranging from 55,000 DWT Panamax-sized vessels to ultra-large crude carriers (ULCCs) of over 440,000 DWT. " Panamax " ships are of the maximum dimensions that will fit through the locks of the Panama Canal. [39]
Supertanker is an informal term used to describe the largest tankers. Today it is applied to very-large crude carriers (VLCC) and ULCCs with capacity over 250,000 DWT. These ships can transport two million barrels of oil. [39] By way of comparison, the oil consumption of Spain and the UK combined is about 3. 2 million barrels (510,000 m³) of oil a day. [40]
Because of their great size, supertankers can't generally enter ports fully loaded. [19] These ships generally take on their cargo at off-shore platforms and single-point moorings. [19] On the other end of the journey, they often pump their cargo off to smaller tankers at designated lighterning points off-coast. [19] A supertanker's routes are generally long, requiring it to stay at sea for extended periods, up to and beyond seventy days at a time. [19]
Smaller tankers, ranging from well under 10,000 DWT to 80,000 DWT Panamax vessels, generally carry refined petroleum products, and are known as product tankers. [39] The smallest tankers, with capacities under 10,000 DWT generally work near-coastal and inland waterways. [39] Although they were in the past, ships of the smaller Aframax and Suezmax classes are no longer regarded as supertankers. An Aframax ship is an oil tanker with capacity between and. Aframax class tankers are largely used in the basins of the Black Sea, the North Sea, the Suezmax is a Naval architecture term for the largest ships capable of transiting the Suez Canal fully loaded and is almost exclusively used in reference to [41]
In 2005, oil tankers made up 36. 9% of the world's fleet in terms of deadweight tonnage. [42] The world's total oil tankers deadweight tonnage has increased from 326. 1 million DWT in 1970 to 960. 0 million DWT in 2005. [42] The combined deadweight tonnage of oil tankers and bulk carriers, represents 72. 9% of the world's fleet. [43]
In 2005, 2. 42 billion metric tons of oil were shipped by tanker. [44] 76. 7% of this was crude oil, and the rest consisted of refined petroleum products. [44] This amounted to 34. 1% of all seaborne trade for the year. [44] Combining the amount carried with the distance it was carried, oil tankers moved 11,705 billion metric-ton-miles of oil in 2005. [45]
By comparison, in 1970 1. 44 billion metric tons of oil were shipped by tanker. [46] This amounted to 34. 1% of all seaborne trade for that year. [47] In terms of amount carried and distance carried, oil tankers moved 6,487 billion ton-miles of oil in 1970. [45]
The United Nations also keeps statistics about oil tanker productivity, stated in terms of metric tons carried per metric ton of deadweight as well as ton-miles of carriage per ton of deadweight. [48] In 2005, for each 1 DWT of oil tankers, 6. 7 metric tons of cargo was carried. [48] Similarly, each 1 DWT of oil tankers was responsible for 32,400 metric-ton miles of carriage. [48]
The main loading ports in 2005 were located in Western Asia, Western Africa, North Africa, and The Caribbean, with 196. Southwest Asia or Southwestern Asia (largely overlapping with the Middle East) is the southwestern portion of Asia. West Africa or Western Africa is the Westernmost Region of the African Continent. North Africa or Northern Africa is the Northernmost Region of the African Continent, separated by the Sahara from Sub-Saharan The Caribbean (ˌkærəˡbiən kæ'rəbiən Cariben|Caraïben or Caraïben; Caraïbe or more commonly Antilles; Caribe is a Region consisting 3, 196. 3, 130. 2 and 246. 6 million metric tons of cargo loaded in these regions. [49] The main discharge ports were located in North America, Europe, and Japan with 537. For a topic outline on this subject see List of basic Japan topics. 7, 438. 4, and 215. 0 million metric tons of cargo discharged in these regions. [49]
As of 2007, the United States Central Intelligence Agency statistics count 4,295 oil tankers of 1,000 long tons of deadweight (DWT) or greater worldwide. near as long as it used to be several months ago It has been actively summarized and split into sub-articles and there is a dynamic talk page discussion of all Deadweight tonnage (also known as deadweight and variously abbreviated as DWT, D [50] Panama was the world's largest flag state for oil tankers, with 528 of the vessels in its registry. Panama, officially the Republic of Panama (República de Panamá) is the southernmost country of Central America. Flag State refers to the Authority under which a country exercises Regulatory control over the Commercial vessel which is registered under its flag [50] Six other flag states had more than 200 registered oil tankers: Liberia (464), Singapore (355), China (252), Russia (250), the Marshall Islands (234) and The Bahamas (209). Liberia, officially the Republic of Liberia, is a country on the west coast of Africa, bordered by Sierra Leone, Guinea, Côte d'Ivoire Singapore China ( Wade-Giles ( Mandarin) Chung¹kuo² is a cultural region, an ancient Civilization, and depending on perspective a National Russia (Россия Rossiya) or the Russian Federation ( Rossiyskaya Federatsiya) is a transcontinental Country extending The Marshall Islands, officially the Republic of the Marshall Islands (RMI is a Micronesian nation of islands in the middle of the Pacific Ocean The Bahamas, officially the Commonwealth of The Bahamas, is an independent sovereign English -speaking country consisting of two thousand Cays and [50] By way of comparison, the United States and the United Kingdom only had 59 and 27 registered oil tankers, respectively. The United States of America —commonly referred to as the The United Kingdom of Great Britain and Northern Ireland, commonly known as the United Kingdom, the UK or Britain,is a Sovereign state located [50]
In 2005, the average age of oil tankers worldwide was 10 years. [51] Of these, 31. 6% were under 4 years old and 14. 3% were over 20 years old. [52]
In 2005, 475 new oil tankers were built, accounting for 30. 7 million DWT. [53] The average size for these new tankers was 64,632 DWT. [53] Nineteen of these were VLCC size, 19 were suezmax, 51 were aframax, and the rest were smaller designs. [53] By way of comparison, 8. 0 million DWT, 8. 7 million DWT, and 20. 8 million DWT worth of oil tanker capacity was built in 1980, 1990, and 2000 respectively. [53]
Ships are generally removed from the fleet through a process known as scrapping. [54] Ship-owners and buyers negotiate scrap prices based on factors such as the ship's empty weight (called light ton displacement or LDT) and prices in the scrap metal market. [55] In 1998, almost 700 ships went through the scrapping process at shipbreakers in places like Alang, India and Chittagong, Bangladesh. WikipediaWikiProject Indian cities for details --> Alang is a Census town in Bhavnagar district in the Indian state Chittagong ( Bengali: চট্টগ্রাম Chôţţogram) is Bangladesh 's main Seaport and its second-largest city [54] In 2004 and 2005, 7. 8 million DWT and 5. 7 million DWT respectively of oil tankers were scrapped. [51] Between 2000 and 2005, the capacity of oil tankers scrapped each year has ranged between 5. 6 million DWT and 18. 4 million DWT. [56] In this same timeframe, tankers have accounted for between 56. 5 and 90. 5 of the world's total scrapped tonnage. [56] During this period, the average age of scrapped oil tankers has ranged from 26. 9 to 31. 5 years. [56]
In 2005, the price for new oil tankers in the 32-45,000 DWT, 80-105,000 DWT, and 250-280,000 DWT ranges were US$43M, $58M, and $120M respectively. The United States dollar ( sign: $; code: USD) is the unit of Currency of the United States; it has also been [57] In 1985, these vessels would have cost $18M, $22M, and $47M respectively. [57]
Oil tankers are often sold second-hand. In 2005, 27. 3 million DWT worth of oil tankers were sold used. [58] Some representative prices for that year include $42. 5M for a 40,000 DWT tanker, $60. 7M for a 80-95,000 DWT, $73M for a 130-150,000 DWT, and $116M for 250-280,00 DWT tanker. [58]
Oil tankers generally have from 8 to 12 tanks. [13] Each tank is split into two or three independent compartments by fore-and-aft bulkheads. [13] The tanks are numbered with tank one being the forwardmost. Individual compartments are referred to by the tank number and the athwartships position, such as "one port," "three starboard," or "six center. "[13]
A cofferdam is a small space left open between two bulkheads, to give protection from heat, fire, or collision. [13] Tankers generally have cofferdams forward and aft of the cargo tanks, and sometimes between individual tanks. [59]
A pumproom houses all the pumps connected to a tanker's cargo lines. [13] Some larger tankers have two pumprooms. [13] A pumproom generally spans the total breadth of the ship. [13]
A major component of tanker architecture is the design of the hull or outer structure. A tanker with a single outer shell between the product and the ocean is said to be single-hulled. [60] Most newer tankers are double-hulled, with an extra space between the hull and the storage tanks. A double hull is a Ship hull design and construction method where the bottom and sides of the ship have two complete layers of watertight hull surface one outer layer [60] Self-descriptive hybrid designs such as double-bottom and double-sided combine aspects of single and double-hull designs. [60]
All single-hulled tankers around the world will be phased out by 2026, in accordance with the International Convention for the Prevention of Pollution from Ships, 1973. Marpol 73/78 is the International Convention for the Prevention of Pollution From Ships 1973 as modified by the Protocol of 1978. [60]
In 1998, the Marine Board of the National Academy of Science conducted a survey of industry experts regarding the pros and cons of double-hull design. The National Academy of Sciences (NAS is a corporation in the United States whose members serve Pro bono as "advisers to the nation on science Some of the advantages of the double-hull design that were mentioned include:
The same report lists the following as some drawbacks to the double-hull design:
In all, double-hull tankers are said to be safer than a single-hull in a grounding incident, especially when the shore is not very rocky. [65]The safety benefits are less clear on larger vessels and in cases of high speed impact. [62]
An oil tanker's inert gas system is one of the most important parts of its design. [66] Fuel oil itself is very difficult to ignite, however its hydrocarbon vapors are explosive when mixed with air in certain concentrations. In Organic chemistry, a hydrocarbon is an Organic compound consisting entirely of Hydrogen and Carbon. [67] The purpose of the system is to create an atmosphere inside tanks in which the hydrocarbon oil vapors cannot burn. [66]
As inert gas is introduced into a mixture of hydrocarbon vapors and air, it increases the lower flammable limit or lowest concentration at which the vapors can be ignited. Lower flammability limit (LFL usually expressed in volume per cent is the lower end of the concentration range of a flammable solvent at a given temperature and pressure for which air/vapor [68] At the same time it decreases the upper flammable limit or highest concentration at which the vapors can be ignited. Flammability limits, also called flammable limits or explosive limits give the proportion of combustible Gases in a mixture between which limits [68] When the total concentration of oxygen in the tank reaches about 11%, the upper and lower flammable limits converge and the flammable range disappears. [69]
Inert gas systems deliver air with an oxygen concentration of less than 5% by volume. [66] As a tank is pumped out, it's filled with inert gas and kept in this safe state until the next cargo is loaded. [70] The exception is in cases when the tank must be entered. [70] Safely gas-freeing a tank is accomplished by purging hydrocarbon vapors with inert gas until the hydrocarbon concentration inside the tank is under about 1%. [70] Thus, as air replaces the inert gas, the concentration cannot rise to the lower flammable limit and is safe. [70]
Operations aboard oil tankers are governed by an established body of best practices and a large body of international law. [71]
Prior to any transfer of cargo, the chief officer must develop a transfer plan detailing specifics of the operation such as how much cargo will be moved, which tanks will be cleaned, and how the ship's ballasting will change. A chief executive officer ( CEO) or chief executive is typically the highest-ranking corporate officer ( executive) or administrator [72] The next step before a transfer is the pretransfer conference. [73] The pretransfer conference covers issues such as:
After the conference is complete, the person in charge on the ship and the person in charge of the shore installation go over a final inspection checklist. [73] In the United States, the checklist is called a Declaration of Inspection or DOI. [73] Outside of the U. S. , the document is called the "Ship/Shore Safety Checklist. "[73] Items on the checklist include:
Loading an oil tanker consists primarily of pumping cargo into the ship's tanks. [74] As oil enters the tank, the vapors inside the tank must be somehow expelled. [74] Depending on local regulations, the vapors can be expelled into the atmosphere or discharged back to the pumping station by way of a vapor recovery line. [74] It is also common for the ship to move water ballast during the loading of cargo to maintain proper trim. [74]
Loading starts slowly at a low pressure to ensure that equipment is working correctly and that connections are secure. [74] Then a steady pressure is achieved and held until the "topping-off" phase when the tanks are nearly full. [74] Topping off is a very dangerous time in handling oil, and the procedure is handled particularly carefully. [74] Tank-gauging equipment is used to tell the person in charge how much space is left in the tank, and all tankers have at least two independent methods for tank-gauging. [74] As the tanker becomes full, crew members open and close valves to direct the flow of product and maintain close communication with the pumping facility to decrease and finally stop the flow of liquid. [74]
The process of moving oil off of a tanker is similar to loading, but has some key differences. [75] The first step in the operation is following the same pretransfer procedures as used in loading. [76] When the transfer begins, it is the ship's cargo pumps that are used to move the product ashore. [76] As in loading, the transfer starts at low pressure to ensure that equipment is working correctly and that connections are secure. [76] Then a steady pressure is achieved and held during the operation. [77] While pumping, tank levels are carefully watched and key locations, such as the connection at the cargo manifold and the ship's pumproom are constantly monitored. [75] Under the direction of the person in charge, crew members open and close valves to direct the flow of product and maintain close communication with the receiving facility to decrease and finally stop the flow of liquid. [75]
Tanks must be cleaned from time to time for various reasons. One reason is to change the type of product carried inside a tank. [78] Also, when tanks are to be inspected or maintenance must be performed within a tank, it must be not only cleaned, but made "gas-free. "[78]
On most crude-oil tankers, a special crude oil washing (COW) system is part of the cleaning process. Crude oil washing (COW is washing out the residue from the tanks of an Oil tanker using the crude oil cargo itself after the cargo tanks have been emptied [78] The COW system circulates part of the cargo through the fixed tank-cleaning system to remove wax and asphaltic deposits. [78]
Tanks that carry less viscous cargoes are washed with water. Fixed and portable automated tank cleaning machines, which clean tanks with high-pressure water jets, are widely used. An automated tank cleaning machine is a machine used to clean cargo tanks such as those found in Tank trucks Rail cars Barges and Oil tankers [78] Some systems use rotating high-pressure water jets to spray hot water on all the internal surfaces of the tank. [78] As the spraying takes place, the liquid is pumped out of the tank. [78]
After a tank is cleaned, it may be gas-freed. "[79] This involves blowing fresh air into the tank to force accumulated gasses out. [79] Specially trained personnel monitor the tank's atmosphere, often using hand-held gas indicators which measure the percentage of hydrocarbons present. [79] When this percentage drops below a value specified in tank-vessel regulations, the tank is declared to be gas-free. [79]
After a tank is gas-free, it may be further hand-cleaned in a manual process known as mucking. [80] Mucking requires protocols for entry into confined spaces, protective clothing, designated safety observers, and possibly the use of airline respirators. Confined space is a term from labor - Safety Regulations that refers to an area whose enclosed conditions and limited access make it dangerous Personal protective equipment (PPE refers to protective Clothing, Helmets, Goggles, or other garment designed to protect the wearer's body or A respirator is a device designed to protect the wearer from inhaling harmful Dusts fumes vapors and/or Gases Respirators come in a wide range of types and sizes [80]
Some sub-types of oil tankers have evolved to meet specific military and economic needs. These sub-types include naval replenishment ships, oil-bulk-ore combination carriers, Floating storage and offloading units (FSOs) and Floating production storage and offloading units (FPSOs). A Floating Production Storage and Offloading vessel ( FPSO; also called a "unit" and a "system" is a type of floating tank system used by the offshore
Replenishment ships, known as oilers in the United States and fleet tankers in Commonwealth countries, are ships that can provide oil products to naval vessels while on the move. A replenishment oiler is a naval auxiliary ship with fuel tanks and dry stores capability which can replenish other ships underway This process, known as underway replenishment, extends the length of time a naval vessel can stay at sea, as well as her effective range. refueling USS Badger (DE-1071 April 1975]] Underway replenishment (UNREP (US Navy or replenishment at sea (RAS (Royal Navy is a method of transferring fuel munitions [81] Prior to underway replenishment, naval vessels had to enter a port or anchor to take on fuel. [16] In addition to fuel, replenishment ships may also deliver water, ammunition, rations, stores and personnel. [17]
An ore-bulk-oil carrier, also known as combination carrier or OBO, is a ship designed to be capable of carrying wet or dry bulk cargoes. An Ore-bulk-oil carrier, also known as combination carrier or OBO, is a Ship designed to be capable of carrying wet or dry Cargoes The idea is Bulk cargo is Commodity Cargo that is transported unpackaged in large quantities [82] This design was intended to provide flexibility in two ways. [83] Firstly, an OBO would be able the shift between the dry and wet bulk trades based on market conditions. [83] Secondly, an OBO could carry oil on one leg of a voyage and return carrying dry bulk, reducing the number of unprofitable ballast voyages it would have to make. Ballast is used in Sailboats to provide moment to resist the lateral forces on the Sail. [84]
In practice, the flexibility which the OBO design allows has gone largely unused, as these ships tend to specialize in either the liquid or dry bulk trade. [84] Also, these ships have endemic maintenance problems. [83] On one hand, due to a less specialized design, an OBO suffers more from wear and tear during dry cargo onload than a bulker. [83] On the other hand, components of the liquid cargo system, from pumps to valves to piping, tend to develop problems when subjected to periods of disuse. [83] These factors have contributed to a steady reduction in the number of OBO ships worldwide since the 1970s. [84]
One of the more famous OBOs was the MV Derbyshire of 180,000 DWT which in September 1980 became the largest British ship ever lost at sea. 2001 RINA Analysis In 2001 Prof Douglas Faulkner Emeritus Professor of Naval architecture, University of Glasgow published a lengthy and highly analytical paper [82] It sank in a Pacific typhoon while carrying a cargo of iron ore from Canada to Japan. Country to "Dominion of Canada" or "Canadian Federation" or anything else please read the Talk Page For a topic outline on this subject see List of basic Japan topics. [82]
Floating storage and offloading units or FSOs are used worldwide by the offshore oil industry to receive oil from nearby platforms and store it until it can be offloaded onto oil tankers. [85] A similar system, the Floating production storage and offloading unit, or FPSO, has the ability to process the product while it is onboard. A Floating Production Storage and Offloading vessel ( FPSO; also called a "unit" and a "system" is a type of floating tank system used by the offshore [85] These floating units reduce oil production costs and offer, mobility, large storage capacity, and production versatility. [85]
FPSO and FSOs are often created out of old, stripped-down oil tankers, but can be made from new-built hulls[85] Shell España first used a tanker as an FPSO was in August 1977. [86] An example of a FSO that used to be an oil tanker is the Knock Nevis. History Knock Nevis was built in 1979 at Sumitomo Heavy Industries 's Oppama Shipyard as Seawise Giant. [87] These units are usually moored to the seabed through a spread mooring system. [85] A turret-style mooring system can be used in areas prone to severe weather. [85] This turret system lets the unit to rotate to minimize the effects of sea-swell and wind. [85]
Oil spills have devastating effects on the environment. Crude oil contains polycyclic aromatic hydrocarbons (PAHs) which is very difficult to clean up, and lasts for years in the sediment and marine environment. Polycyclic aromatic hydrocarbons ( PAH s are Chemical compounds that consist of fused Aromatic rings and do not contain Heteroatoms or Sediment is any particulate matter that can be transported by fluid flow and which eventually is deposited as a layer of solid particles on the bed or bottom of a body of [89] Marine species constantly exposed to PAHs can exhibit developmental problems, susceptibility to disease, and abnormal reproductive cycles.
By the sheer amount of oil carried, modern oil tankers must be considered something of a threat to the environment. As discussed above, a VLCC tanker can carry 2 million barrels (320,000 m³) of crude oil, or 62,000,000 gallons. This is more than six times the amount spilled in the widely known Exxon Valdez incident. The Exxon Valdez oil spill occurred in Prince William Sound, Alaska, on March 24 1989 In this spill, the ship ran aground and dumped 10. 8 million gallons of oil into the ocean in March of 1989. Despite efforts of scientists, managers, and volunteers over 400,000 seabirds, about 1,000 sea otters, and immense numbers of fish were killed. Seabirds are Birds that have adapted to life within the marine environment The sea otter ( Enhydra lutris) is a Marine mammal native to the coasts of the northern and eastern North Pacific Ocean. [89]
But how much do tankers contribute to oil pollution in the oceans? According to the United States Coast Guard, 35. 7 % of the volume of oil spilled in the U. S. from 1991 to 2004 came from tank vessels (ships/barges), 27. 6 % from facilities and other non-vessels, 19. 9% from non-tank vessels, and 9. 3 % from pipelines; 7. 4 % from mystery spills. [90] On the other hand, only 5% of the actual spills came from oil tankers, while 51. 8% came from other kinds of vessels. [90] The detailed statistics for 2004 shown in the table below show tank vessels responsible for somewhat less than 5 % of the number of total spills but more than 60% of the volume. In summary, spills are much more rare but much more serious on tank vessels than on non-tank vessels.
| U. S. C. G Spill Compendium Annual Data for 2004[91] | |||||||
| Source | Number of spills | % of spill incidents | Spill volume (gallons) | % of spill volume | Average spill size | Median spill size | Maximum spill size |
|---|---|---|---|---|---|---|---|
| TANKSHIP | 35 | 0. 90% | 636,834 | 45. 00% | 18,195 | 1 | 329,678 |
| TANKBARGE | 143 | 3. 70% | 215,822 | 15. 20% | 1,509 | 3 | 151,200 |
| ALL OTHER VESSELS | 1527 | 39. 20% | 453,901 | 32. 00% | 297 | 3 | 335,732 |
| FACILITIES | 1099 | 28. 20% | 42,675 | 3. 00% | 39 | 1 | 2,100 |
| PIPELINES | 1 | 0. 00% | 15,000 | 1. 10% | 15,000 | 15,000 | |
| ALL OTHER NON-VESSEL SOURCES | 37 | 0. 90% | 12,781 | 0. 90% | 345 | 5 | 12,000 |
| UNKNOWN or OTHER | 1055 | 27. 10% | 39,700 | 2. 80% | 38 | 1 | 8,000 |
| YEAR-END STATISTICS | 3897 | 100. 00% | 1,416,714 | 100. 00% | 364 | 2 | 335,732 |
The International Tanker Owners Pollution Federation has tracked 9,351 accidental spills that have occurred since 1974. [92] According to this study, most spills result from routine operations such as loading cargo, discharging cargo, and taking on fuel oil. [92] 91% of the operational oil spills are small, resulting in less than 7 tons per spill. [92] On the other hand, spills resulting from accidents like collisions, groundings, hull failures, and explosions are much larger, with 84% of these involving losses of over 700 tons. [92]
Following the Exxon Valdez spill, the United States passed the Oil Pollution Act of 1990 (OPA-90), which included a stipulation that all tankers entering its waters be double-hulled by 2015. The Oil Pollution Act (101 HR1465 PL 101-380) was passed by the United States Congress to prevent further Oil spills from occurring in the United States History The technology of oil transportation has evolved alongside the oil industry Following the sinkings of the Erika (1999) and Prestige (2002), the European Union passed its own stringent anti-pollution packages (known as Erika I, II, and III), which also require all tankers entering its waters to be double-hulled by 2010. Erika was the name of a tanker built in 1975 and last chartered by Total-Fina-Elf. The Prestige was an Oil tanker whose sinking in 2002 off the Galician coast caused a large Oil spill. The European Union ( EU) is a political and economic union of twenty-seven member states, located primarily in The Erika packages are controversial because they introduced the new legal concept of "serious negligence". [93]