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100-605: The T2 tanker , or T2 , was a class of oil tanker constructed and produced in large numbers in the United States during World War II . Only the T3 tankers were larger "navy oilers" of the period. Some 533 T2s were built between 1940 and the end of 1945. They were used to transport fuel oil , diesel fuel , gasoline and sometimes black oil-crude oil . Post war many T2s remained in use; like other hastily built World War II ships pressed into peacetime service, there were safety concerns. As

200-529: A η j {\displaystyle P_{br}={\frac {P_{a}}{\eta _{j}}}} The corresponding fuel weight flow rates can be computed now: F = c p P b r {\displaystyle F=c_{p}P_{br}} Thrust power is the speed multiplied by the drag, is obtained from the lift-to-drag ratio : P a = V C D C L W g ; {\displaystyle P_{a}=V{\frac {C_{D}}{C_{L}}}Wg;} here Wg

300-785: A = 7 5 R s T {\textstyle a={\sqrt {{\frac {7}{5}}R_{s}T}}} ; here R s {\displaystyle R_{s}} is the specific heat constant of air 287.16 J/kg K (based on aviation standards) and γ = 7 / 5 = 1.4 {\displaystyle \gamma =7/5=1.4} (derived from γ = c p c v {\textstyle \gamma ={\frac {c_{p}}{c_{v}}}} and c p = c v + R s {\displaystyle c_{p}=c_{v}+R_{s}} ). c p {\displaystyle c_{p}} and c v {\displaystyle c_{v}} are

400-464: A Kennebec -class oiler. In 1966, the US Army reactivated 11 T2 tankers and converted them into floating electrical power generation plants and deployed them to Vietnam . The ships' propulsion systems' electrical turbines were used to generate electricity for on-shore use, drawing on fuel from the ships' 150,000-barrel holds. This allowed the ships to produce electricity for two years without refueling for

500-549: A ship built for merchant service which could be militarized as a fleet auxiliary in time of war. MarCom subsidized the excess cost of naval features beyond normal commercial standards. The T2 was based on two ships built in 1938–1939 by Bethlehem Steel for Socony-Vacuum Oil Company , Mobilfuel and Mobilube , differing from the Mobil ships principally in the installation of more powerful engines for higher speed. Standard T2s were 501 ft 6 in (152.9 m) in total length, with

600-532: A thrust specific fuel consumption , so that rate of fuel flow is proportional to drag , rather than power. F = c T T = c T C D C L W {\displaystyle F=c_{T}T=c_{T}{\frac {C_{D}}{C_{L}}}W} Using the lift equation, 1 2 ρ V 2 S C L = W {\displaystyle {\frac {1}{2}}\rho V^{2}SC_{L}=W} where ρ {\displaystyle \rho }

700-559: A 40,000  DWT tanker, $ 60.7 million for a 80,000–95,000  DWT , $ 73 million for a 130,000–150,000  DWT , and $ 116 million for 250,000–280,000  DWT tanker. For a concrete example, in 2006, Bonheur subsidiary First Olsen paid $ 76.5 million for Knock Sheen , a 159,899 DWT tanker. The cost of operating the largest tankers, the Very Large Crude Carriers, is currently between $ 10,000 and $ 12,000 per day. Oil tankers generally have from 8 to 12 tanks. Each tank

800-470: A beam of 68 ft (20.7 m). Rated at 9,900 tons gross (GRT), with 15,850 long tons deadweight (DWT), standard T2s displaced about 21,100 tons. Steam turbines driving a single propeller at 12,000 horsepower (8,900  kW ) delivered a top speed of 16 knots (30 km/h; 18 mph). Six were built for commerce by Bethlehem-Sparrows Point Shipyard in Maryland , only to be taken over by

900-487: A country, called its flag state . A ship's flag state exercises regulatory control over the vessel and is required to inspect it regularly, certify the ship's equipment and crew, and issue safety and pollution prevention documents. As of 2007, the United States Central Intelligence Agency statistics count 4,295 oil tankers of 1,000 long tons deadweight (DWT) or greater worldwide. Panama

1000-639: A lift-to-drag ratio of 18:1, and a structural efficiency of 50%, the cruise range would be The range equation may be further extended to consider operational factors by including an operational efficiency ("ops" for flight operations) R = Z f η eng η aero η struc η ops {\displaystyle R=Z_{f}\eta _{\text{eng}}\eta _{\text{aero}}\eta _{\text{struc}}\eta _{\text{ops}}} The operational efficiency η o p s {\displaystyle \eta _{ops}} may be expressed as

1100-510: A number of airplane weights from the equilibrium condition P a = P r {\displaystyle P_{a}=P_{r}} is noted . To each flight velocity, there corresponds a particular value of propulsive efficiency η j {\displaystyle \eta _{j}} and specific fuel consumption c p {\displaystyle c_{p}} . The successive engine powers can be found: P b r = P

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1200-550: A number of challenges. A primary concern was to keep the cargo and fumes well away from the engine room to avoid fires. Other challenges included allowing for the cargo to expand and contract due to temperature changes, and providing a method to ventilate the tanks. The first successful oil tanker was Zoroaster , built by Sven Alexander Almqvist in Motala Verkstad , which carried its 246 metric tons (242 long tons ) of kerosene cargo in two iron tanks joined by pipes. One tank

1300-414: A number of damaging and high-profile oil spills . The technology of oil transportation has evolved alongside the oil industry. Although human use of oil reaches to prehistory, the first modern commercial exploitation dates back to James Young 's manufacture of paraffin in 1850. In the early 1850s, oil began to be exported from Upper Burma, then a British colony. The oil was moved in earthenware vessels to

1400-615: A specific range and fuel weight flow rate can be related to the characteristics of the airplane and propulsion system; if these are constant: R = η j g c p C L C D ln ⁡ W 1 W 2 = V ( L / D ) I s p L n ( W i / W f ) {\displaystyle R={\frac {\eta _{j}}{gc_{p}}}{\frac {C_{L}}{C_{D}}}\ln {\frac {W_{1}}{W_{2}}}=V(L/D)IspLn(Wi/Wf)} An electric aircraft with battery power only will have

1500-987: A top speed approaching 16 + 1 ⁄ 2 knots (30.6 km/h; 19.0 mph). All five were requisitioned by the Navy during the war and converted to fleet oilers as the Mattaponi class. By far the most common variety of the T2-type tanker was the T2-SE-A1, another commercial design already being built in 1940 by the Sun Shipbuilding Company for Standard Oil Company of New Jersey. They were 523 ft (159.4 m) long, 68 ft (20.7 m) abeam, with 10,448  gross register tons  (GRT) and 16,613  DWT . Their (steam) turbo-electric transmission system delivered 6,000 shaft horsepower (4,500 kW), with maximum thrust of 7,240 horsepower (5,400 kW), which produced

1600-419: A top speed of 17.5 knots (32.4 km/h; 20.1 mph). The first Navy commissioning was in 1942. could hold 117,400 Bbls of oil and 595,000 gal of gasoline. Crew of 23 officers and 329 enlisted men. Armament: one single 5'/38 cal dual-purpose gun mount, four single 3"/50 cal dual-purpose gun mounts, four twin 40 mm AA gun mounts and twelve single 20 mm AA gun mounts. Example was USS  Patuxent ,

1700-672: A top-rated speed of about 15 knots (28 km/h; 17 mph) with a cruising range of up to 12,600 miles (20,300 km). After Pearl Harbor, the United States Maritime Commission ordered this model built en masse to supply U.S. warships already in accelerated production, and provide for the fuel needs of US forces in Europe and the Pacific, as well as to replace the tanker tonnage being lost at an alarming rate to German U-boats. 481 were built in extremely short production times by

1800-557: Is d W d R = d W d t d R d t = − F V , {\displaystyle {\frac {dW}{dR}}={\frac {\frac {dW}{dt}}{\frac {dR}{dt}}}=-{\frac {F}{V}},} where V {\displaystyle V} is the speed), so that d R d t = − V F d W d t {\displaystyle {\frac {dR}{dt}}=-{\frac {V}{F}}{\frac {dW}{dt}}} It follows that

1900-1227: Is a height that a quantity of fuel could lift itself in the Earth's gravity field (assumed constant) by converting its chemical energy into potential energy. Z f {\displaystyle Z_{f}} for kerosene jet fuel is 2,376 nautical miles (4,400 km) or about 69% of the Earth's radius . There are two useful alternative ways to express the structural efficiency η struc = ln ⁡ W ^ 1 W ^ 2 = ln ⁡ ( 1 + W fuel W ^ 2 ) = − ln ⁡ ( 1 − W fuel W ^ 1 ) {\displaystyle \eta _{\text{struc}}=\ln {\frac {{\widehat {W}}_{1}}{{\widehat {W}}_{2}}}=\ln \left(1+{\frac {{W}_{\text{fuel}}}{{\widehat {W}}_{2}}}\right)=-\ln \left(1-{\frac {{W}_{\text{fuel}}}{{\widehat {W}}_{1}}}\right)} As an example, with an overall engine efficiency of 40%,

2000-526: Is again mass. When cruising at a fixed height, a fixed angle of attack and a constant specific fuel consumption, the range becomes: R = 2 c T C L C D 2 2 g ρ S ( W 1 − W 2 ) {\displaystyle R={\frac {2}{c_{T}}}{\sqrt {{\frac {C_{L}}{C_{D}^{2}}}{\frac {2}{g\rho S}}}}\left({\sqrt {W_{1}}}-{\sqrt {W_{2}}}\right)} where

2100-429: Is assumed that the thrust specific fuel consumption is constant as the aircraft weight decreases. This is generally not a good approximation because a significant portion (e.g. 5% to 10%) of the fuel flow does not produce thrust and is instead required for engine "accessories" such as hydraulic pumps , electrical generators , and bleed air powered cabin pressurization systems. This can be accounted for by extending

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2200-404: Is assumed. The relationship D = C D C L W {\displaystyle D={\frac {C_{D}}{C_{L}}}W} is used. The thrust can now be written as: T = D = C D C L W ; {\displaystyle T=D={\frac {C_{D}}{C_{L}}}W;} here W is a force in newtons Jet engines are characterized by

2300-413: Is more efficient, and better protection in low-impact collisions and grounding. The same report lists the following as some drawbacks to the double-hull design, including higher build costs, greater operating expenses (e.g. higher canal and port tariffs), difficulties in ballast tank ventilation, the fact that ballast tanks need continuous monitoring and maintenance, increased transverse free surface,

2400-454: Is split into two or three independent compartments by fore-and-aft bulkheads. 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". A cofferdam is a small space left open between two bulkheads, to give protection from heat, fire, or collision. Tankers generally have cofferdams forward and aft of

2500-451: Is the air density , and S the wing area , the specific range is found equal to: V F = 1 c T C L C D 2 2 ρ S W {\displaystyle {\frac {V}{F}}={\frac {1}{c_{T}}}{\sqrt {{\frac {C_{L}}{C_{D}^{2}}}{\frac {2}{\rho SW}}}}} Inserting this into ( 1 ) and assuming only W {\displaystyle W}

2600-628: Is the energy per mass of the battery (e.g. 150-200 Wh/kg for Li-ion batteries), η total {\displaystyle \eta _{\text{total}}} the total efficiency (typically 0.7-0.8 for batteries, motor, gearbox and propeller), L / D {\displaystyle L/D} lift over drag (typically around 18), and the weight ratio W battery / W total {\displaystyle {W_{\text{battery}}}/{W_{\text{total}}}} typically around 0.3. The range of jet aircraft can be derived likewise. Now, quasi-steady level flight

2700-412: Is the speed, and F {\displaystyle F} is the fuel consumption rate, is called the specific range (= range per unit mass of fuel; S.I. units: m/kg). The specific range can now be determined as though the airplane is in quasi-steady-state flight. Here, a difference between jet and propeller-driven aircraft has to be noticed. With propeller-driven propulsion, the level flight speed at

2800-607: Is the weight (force in newtons, if W is the mass in kilograms); g is standard gravity (its exact value varies, but it averages 9.81 m/s ). The range integral, assuming flight at a constant lift to drag ratio, becomes R = η j g c p C L C D ∫ W 2 W 1 d W W {\displaystyle R={\frac {\eta _{j}}{gc_{p}}}{\frac {C_{L}}{C_{D}}}\int _{W_{2}}^{W_{1}}{\frac {dW}{W}}} To obtain an analytic expression for range,

2900-503: Is the zero-fuel mass and W f {\displaystyle W_{f}} the mass of the fuel, the fuel consumption rate per unit time flow F {\displaystyle F} is equal to − d W f d t = − d W d t . {\displaystyle -{\frac {dW_{f}}{dt}}=-{\frac {dW}{dt}}.} The rate of change of aircraft mass with distance R {\displaystyle R}

3000-490: Is varying, the range (in kilometers) becomes: R = 1 c T C L C D 2 2 g ρ S ∫ W 2 W 1 1 W d W ; {\displaystyle R={\frac {1}{c_{T}}}{\sqrt {{\frac {C_{L}}{C_{D}^{2}}}{\frac {2}{g\rho S}}}}\int _{W_{2}}^{W_{1}}{\frac {1}{\sqrt {W}}}dW;} here W {\displaystyle W}

3100-772: The Alabama Drydock and Shipbuilding Company of Mobile, Alabama , the Kaiser Company at their Swan Island Yard at Portland, Oregon , the Marinship Corp. of Sausalito, California , and the Sun Shipbuilding and Drydock Company of Chester, Pennsylvania . During that period, average production time from laying of the keel to "fitting out" was 70 days. The record, however, was held by Marinship, which had Huntington Hills ready for sea trials in just 33 days. The T2-SE-A2 variation, built only by Marinship of Sausalito,

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3200-734: The Baltic Sea , Lake Ladoga , Lake Onega , the Rybinsk and Mariinsk Canals and the Volga River . The aft and the stern was put together and then dismantled to make room for the mid-section as the Caspian Sea was reached. In 1883, oil tanker design took a large step forward. Working for the Nobel company, British engineer Colonel Henry F. Swan designed a set of three Nobel tankers. Instead of one or two large holds, Swan's design used several holds which spanned

3300-464: The London Tanker Brokers' Panel (LTBP) . At first, they divided the groups as General Purpose for tankers under 25,000 tons deadweight (DWT); Medium Range for ships between 25,000 and 45,000 DWT and Long Range for the then-enormous ships that were larger than 45,000 DWT. The ships became larger during the 1970s, which prompted rescaling. The system was developed for tax reasons as

3400-511: The Oppama shipyard by Sumitomo Heavy Industries, Ltd. , named Seawise Giant . This ship was built with a capacity of 564,763  DWT , a length overall of 458.45 metres (1,504.1 ft) and a draft of 24.611 metres (80.74 ft). She had 46 tanks, 31,541 square metres (339,500 sq ft) of deck, and at her full load draft, could not navigate the English Channel . Seawise Giant

3500-647: The Standard Oil Company along with several of her sister ships . After Glückauf was lost in 1893 after being grounded in fog, Standard Oil purchased the sister ships. The 1880s also saw the beginnings of the Asian oil trade. The idea that led to moving Russian oil to the Far East via the Suez Canal was the brainchild of two men: importer Marcus Samuel and shipowner/broker Fred Lane. Prior bids to move oil through

3600-698: The United States Navy following the Attack on Pearl Harbor as the Kennebec -class oiler . Keystone Tankships company ordered five tankers in 1940 from Sun Shipbuilding & Drydock of Chester, Pennsylvania, based on the T2 but longer and with increased capacity; Marcom would designate this design T2-A. Bigger but faster, they were 526 ft (160.3 m) in total length, displaced about 22,445 tons, and were rated at 10,600 tons gross with 16,300  DWT — yet they attained

3700-533: The V-Plus size designation. With the exception of the pipeline, the tanker is the most cost-effective way to move oil today. Worldwide, tankers carry some 2 billion barrels (3.2 × 10  L) annually, and the cost of transportation by tanker amounts to only US$ 0.02 per gallon at the pump. In 1954, Shell Oil developed the "average freight rate assessment" (AFRA) system which classifies tankers of different sizes. To make it an independent instrument, Shell consulted

3800-739: The Vietnam War . USNS  French Creek was the first to arrive in June 1966, then next was USS  Kennebago , both installed in Cam Ranh Bay . Oil tanker 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 metric tons of deadweight (DWT) to ultra-large crude carriers (ULCCs) of 550,000  DWT . Tankers move approximately 2.0  billion metric tons (2.2 billion short tons ) of oil every year. Second only to pipelines in terms of efficiency,

3900-517: The great-circle distance divided by the actual route distance η route = D GC D actual {\displaystyle \eta _{\text{route}}={\frac {D_{\text{GC}}}{D_{\text{actual}}}}} Off-nominal temperatures may be accounted for with a temperature efficiency factor η temp {\displaystyle \eta _{\text{temp}}} (e.g. 99% at 10 deg C above International Standard Atmosphere (ISA) temperature). All of

4000-728: The thrust specific fuel consumption has been adjusted down and the virtual aircraft weight has been adjusted up to maintain the proper fuel flow while making the adjusted thrust specific fuel consumption truly constant (not a function of virtual weight). Then, the modified Breguet range equation becomes R = a M g c ^ T C L C D ln ⁡ W ^ 1 W ^ 2 {\displaystyle R={\frac {aM}{g{\widehat {c}}_{T}}}{\frac {C_{L}}{C_{D}}}\ln {\frac {{\widehat {W}}_{1}}{{\widehat {W}}_{2}}}} The above equation combines

4100-527: The French aviation pioneer, Louis Charles Breguet . It is possible to improve the accuracy of the Breguet range equation by recognizing the limitations of the conventionally used relationships for fuel flow: F = c T T = c T C D C L W {\displaystyle F=c_{T}T=c_{T}{\frac {C_{D}}{C_{L}}}W} In the Breguet range equation, it

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4200-515: The Greek Hellespont Steamship Corporation. Hellespont sold these ships to Overseas Shipholding Group and Euronav in 2004. Each of the sister ships has a capacity of over 441,500  DWT , a length overall of 380.0 metres (1,246.7 ft) and a cargo capacity of 3,166,353 barrels (503,409,900 L). They were the first ULCCs to be double-hulled. To differentiate them from smaller ULCCs, these ships are sometimes given

4300-562: The Marine Board of the National Academy of Sciences conducted a survey of industry experts regarding the pros and cons of double-hull design. Some of the advantages of the double-hull design that were mentioned include ease of ballasting in emergency situations, reduced practice of saltwater ballasting in cargo tanks decreases corrosion, increased environmental protection, cargo discharge is quicker, more complete and easier, tank washing

4400-744: The Suez Canal contributed, as did nationalization of Middle East oil refineries . Fierce competition among shipowners also played a part. 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. In 1955 the world's largest supertanker was 30,708  GRT and 47,500 LT  DWT : SS Spyros Niarchos launched that year by Vickers Armstrongs Shipbuilders Ltd in England for Greek shipping magnate Stavros Niarchos . In 1958 United States shipping magnate Daniel K. Ludwig broke

4500-505: The United Kingdom consumed about 1.6 million barrels (250,000 m ) of oil per day in 2009. ULCCs commissioned in the 1970s were the largest vessels ever built, but have all now been scrapped. A few newer ULCCs remain in service, none of which are more than 400 meters long. Because of their size, supertankers often cannot enter port fully loaded. These ships can take on their cargo at offshore platforms and single-point moorings . On

4600-456: The United States and the United Kingdom only had 59 and 27 registered oil tankers, respectively. In 2005, the average age of oil tankers worldwide was 10 years. Of these, 31.6% were under 4 years old and 14.3% were over 20 years old. In 2005, 475 new oil tankers were built, accounting for 30.7 million  DWT . The average size for these new tankers was 64,632  DWT . Nineteen of these were VLCC size, 19 were Suezmax, 51 were Aframax, and

4700-686: The assumed fuel flow formula in a simple way where an "adjusted" virtual aircraft gross weight W ^ {\displaystyle {\widehat {W}}} is defined by adding a constant additional "accessory" weight W acc {\displaystyle W_{\text{acc}}} . W ^ = W + W acc {\displaystyle {\widehat {W}}=W+W_{\text{acc}}} F = c ^ T C D C L W ^ {\displaystyle F={\widehat {c}}_{T}{\frac {C_{D}}{C_{L}}}{\widehat {W}}} Here,

4800-452: The average cost of transport of crude oil by tanker amounts to only US$ 5 to $ 8 per cubic metre ($ 0.02 to $ 0.03 per US gallon). Some specialized types of oil tankers have evolved. One of these is the naval replenishment oiler , a tanker which can fuel a moving vessel . Combination ore-bulk-oil carriers and permanently moored floating storage units are two other variations on the standard oil tanker design. Oil tankers have been involved in

4900-526: The canal had been rejected by the Suez Canal Company as being too risky. Samuel approached the problem a different way: asking the company for the specifications of a tanker it would allow through the canal. Armed with the canal company's specifications, Samuel ordered three tankers from William Gray & Company in northern England. Named Murex , Conch and Clam , each had a capacity of 5,010 long tons of deadweight. These three ships were

5000-487: The cargo tanks, and sometimes between individual tanks. A pumproom houses all the pumps connected to a tanker's cargo lines. Some larger tankers have two pumprooms. A pumproom generally spans the total breadth of the ship. 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". Most newer tankers are " double hulled ", with an extra space between

5100-479: The charterer. Time charter arrangements specify a daily rate, and port costs and voyage expenses are also generally paid by the charterer. The Worldwide Tanker Normal Freight Scale, often referred to as Worldscale, is established and governed jointly by the Worldscale Associations of London and New York. Worldscale establishes a baseline price for carrying a metric ton of product between any two ports in

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5200-509: The company had 34 steam-driven oil tankers, compared to Standard Oil's four case-oil steamers and 16 sailing tankers. Until 1956, tankers were designed to be able to navigate the Suez Canal. This size restriction became much less of a priority after the closing of the canal during the Suez Crisis of 1956. Forced to move oil around the Cape of Good Hope , shipowners realized that bigger tankers were

5300-437: The compressibility on the aerodynamic characteristics of the airplane are neglected as the flight speed reduces during the flight. For jet aircraft operating in the stratosphere (altitude approximately between 11 and 20 km), the speed of sound is approximately constant, hence flying at a fixed angle of attack and constant Mach number requires the aircraft to climb (as weight decreases due to fuel burn), without changing

5400-416: The crew and maintaining the vessel. Finally, in a contract of affreightment or COA, the charterer specifies a total volume of cargo to be carried in a specific time period and in specific sizes, for example a COA could be specified as 1 million barrels (160,000 m ) of JP-5 in a year's time in 25,000-barrel (4,000 m ) shipments. One of the key aspects of any charter party is the freight rate , or

5500-490: The cross-country ground speed multiplied by the maximum time in the air. The fuel time limit for powered aircraft is fixed by the available fuel (considering reserve fuel requirements) and rate of consumption. Some aircraft can gain energy while airborne through the environment (e.g. collecting solar energy or through rising air currents from mechanical or thermal lifting) or from in-flight refueling. These aircraft could theoretically have an infinite range. Ferry range means

5600-499: The demand for new ships started to grow, resulting in 2007 in a record breaking order backlog for shipyards, exceeding their capacity with rising newbuilding prices as a result. This resulted in a glut of ships when demand dropped due to a weakened global economy and dramatically reduced demand in the United States. The charter rate for very large crude carriers, which carry two million barrels of oil, had peaked at $ 309,601 per day in 2007 but had dropped to $ 7,085 per day by 2012, far below

5700-698: The energy characteristics of the fuel with the efficiency of the jet engine. It is often useful to separate these terms. Doing so completes the nondimensionalization of the range equation into fundamental design disciplines of aeronautics . R = Z f a M Z f g c ^ T C L C D ln ⁡ W ^ 1 W ^ 2 {\displaystyle R=Z_{f}{\frac {aM}{Z_{f}g{\widehat {c}}_{T}}}{\frac {C_{L}}{C_{D}}}\ln {\frac {{\widehat {W}}_{1}}{{\widehat {W}}_{2}}}} where giving

5800-426: The final form of the theoretical range equation (not including operational factors such as wind and routing) R = Z f η eng η aero η struc {\displaystyle R=Z_{f}\eta _{\text{eng}}\eta _{\text{aero}}\eta _{\text{struc}}} The geopotential energy height of the fuel is an intensive property . A physical interpretation

5900-463: The first oil-tank steamer, Vaderland (Fatherland), which was built by Palmers Shipbuilding and Iron Company for Belgian owners. The vessel's use was curtailed by US and Belgian authorities citing safety concerns. 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. The modern oil tanker was developed in

6000-560: The first tankers of the Tank Syndicate, forerunner of today's Royal Dutch Shell company. With facilities prepared in Jakarta , Singapore , Bangkok , Saigon , Hong Kong , Shanghai , and Kobe , the fledgling Shell company was ready to become Standard Oil's first challenger in the Asian market. On August 24, 1892, Murex became the first tanker to pass through the Suez Canal . By the time Shell merged with Royal Dutch Petroleum in 1907,

6100-617: The greater number of surfaces to maintain, the risk of explosions in double-hull spaces if a vapor detection system not fitted, and that cleaning ballast tanks is more difficult for double hull ships. Range (vehicle) The maximal total range is the maximum distance an aircraft can fly between takeoff and landing . Powered aircraft range is limited by the aviation fuel energy storage capacity (chemical or electrical) considering both weight and volume limits. Unpowered aircraft range depends on factors such as cross-country speed and environmental conditions. The range can be seen as

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6200-531: The hull and the storage tanks. Hybrid designs such as "double-bottom" and "double-sided" combine aspects of single and double-hull designs. 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). The United Nations has decided to phase out single hull oil tankers by 2010. In 1998,

6300-522: The key to more efficient transport. While a typical T2 tanker of the World War II era was 162 metres (532 ft) long and had a capacity of 16,500  DWT , the ultra-large crude carriers (ULCC) built in the 1970s were over 400 metres (1,300 ft) long and had a capacity of 500,000  DWT . Several factors encouraged this growth. Hostilities in the Middle East which interrupted traffic through

6400-632: The maximum flight time is variable, limited by available daylight hours, aircraft design (performance), weather conditions, aircraft potential energy, and pilot endurance. Therefore, the range equation can only be calculated exactly for powered aircraft. It will be derived for both propeller and jet aircraft. If the total mass W {\displaystyle W} of the aircraft at a particular time t {\displaystyle t} is: W = W 0 + W f , {\displaystyle W=W_{0}+W_{f},} where W 0 {\displaystyle W_{0}}

6500-480: The maximum range that an aircraft engaged in ferry flying can achieve. This usually means maximum fuel load, optionally with extra fuel tanks and minimum equipment. It refers to the transport of aircraft without any passengers or cargo. Combat radius is a related measure based on the maximum distance a warplane can travel from its base of operations, accomplish some objective, and return to its original airfield with minimal reserves. For most unpowered aircraft,

6600-438: The operating costs of these ships. As a result, several tanker operators laid up their ships. Prices rose significantly in 2015 and early 2016, but delivery of new tankers was projected to keep prices in check. Owners of large oil tanker fleets include Teekay Corporation , A P Moller Maersk , DS Torm , Frontline , MOL Tankship Management , Overseas Shipholding Group , and Euronav . In 2005, oil tankers made up 36.9% of

6700-437: The operational efficiency factors may be collected into a single term η ops = η route η wind η temp ⋯ {\displaystyle \eta _{\text{ops}}=\eta _{\text{route}}\eta _{\text{wind}}\eta _{\text{temp}}\cdots } While the peak value of a specific range would provide maximum range operation, long-range cruise operation

6800-623: The original T2s except for having less powerful engines of 7,700 hp (5,700 kW). Twenty-five of this design were ordered by the Maritime Commission, of which five became Navy oilers as the Chiwawa class . T2-A-MC-K had a M.C. deadweight tonnage of 16,300 and a full load tonnage of 22,445. The dimensions were: Length: 526 ft (160 m), Beam: 68 ft (21 m) and max. draft: 30 ft 10 in (9.40 m). Powered by turbine engines rated at 12,000 hp (8,900 kW) with

6900-430: The other end of the journey, they often pump their cargo off to smaller tankers at designated lightering points off-coast. Supertanker routes are typically long, requiring them to stay at sea for extended periods, often around seventy days at a time. The act of hiring a ship to carry cargo is called chartering. (The contract itself is known as a charter party . ) Tankers are hired by four types of charter agreements:

7000-425: The past, ships of the smaller Aframax and Suezmax classes are no longer regarded as supertankers. "Supertankers" are the largest oil tankers, and the largest mobile man-made structures. They include very large and ultra-large crude carriers (VLCCs and ULCCs – see above) with capacities over 250,000 DWT. These ships can transport 2,000,000 barrels (320,000 m ) of oil/318,000 metric tons. By way of comparison,

7100-499: The period from 1877 to 1885. In 1876, Ludvig and Robert Nobel , brothers of Alfred Nobel , founded Branobel (short for Brothers Nobel) in Baku , Azerbaijan . It was, during the late 19th century, one of the largest oil companies in the world. Ludvig was a pioneer in the development of early oil tankers. He first experimented with carrying oil in bulk on single-hulled barges. Turning his attention to self-propelled tankships, he faced

7200-581: The price specified for carriage of cargo. The freight rate of a tanker charter party is specified in one of four ways: by a lump sum rate, by rate per ton, by a time charter equivalent rate, or by Worldscale rate. In a lump sum rate arrangement, a fixed price is negotiated for the delivery of a specified cargo, and the ship's owner/operator is responsible to pay for all port costs and other voyage expenses. Rate per ton arrangements are used mostly in chemical tanker chartering, and differ from lump sum rates in that port costs and voyage expenses are generally paid by

7300-422: The problem suggested the cause was poor welding techniques. It was found the steel (that had been successfully used in riveted ship design) was not well suited for the new wartime welding construction. The high sulfur content made the steel brittle and prone to metal fatigue at lower temperatures. The T2 design was formalized by the United States Maritime Commission as its medium-sized "National Defense tanker",

7400-587: The product of individual operational efficiency terms. For example, average wind may be accounted for using the relationship between average GroundSpeed (GS), True AirSpeed (TAS, assumed constant), and average HeadWind (HW) component. η wind = T A S − H W avg T A S = G S avg T A S {\displaystyle \eta _{\text{wind}}={\frac {TAS-HW_{\text{avg}}}{TAS}}={\frac {GS_{\text{avg}}}{TAS}}} Routing efficiency may be defined as

7500-528: The range is obtained from the definite integral below, with t 1 {\displaystyle t_{1}} and t 2 {\displaystyle t_{2}} the start and finish times respectively and W 1 {\displaystyle W_{1}} and W 2 {\displaystyle W_{2}} the initial and final aircraft masses The term V F {\textstyle {\frac {V}{F}}} , where V {\displaystyle V}

7600-468: The record of 100,000 long tons of heavy displacement. His Universe Apollo displaced 104,500 long tons, a 23% increase from the previous record-holder, Universe Leader which also belonged to Ludwig. The first tanker over 100,000 dwt built in Europe was the British Admiral . The ship was launched at Barrow-in-Furness in 1965 by Elizabeth II . The world's largest supertanker was built in 1979 at

7700-788: The rest consisted of refined petroleum products. This amounted to 34.1% of all seaborne trade for the year. Combining the amount carried with the distance it was carried, oil tankers moved 11,705 billion metric-ton-miles of oil in 2005. By comparison, in 1970 1.44 billion metric tons of oil were shipped by tanker. This amounted to 34.1% of all seaborne trade for that year. In terms of amount carried and distance carried, oil tankers moved 6,487 billion metric-ton-miles of oil in 1970. 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 metric-ton-miles of carriage per metric ton of deadweight. In 2005, for each 1  DWT of oil tankers, 6.7 metric tons of cargo

7800-434: The rest were smaller designs. By 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. Ships are generally removed from the fleet through a process known as scrapping . 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

7900-496: The river bank where it was then poured into boat holds for transportation to Britain. In the 1860s, Pennsylvania oil fields became a major supplier of oil, and a center of innovation after Edwin Drake had struck oil near Titusville, Pennsylvania . Break-bulk boats and barges were originally used to transport Pennsylvania oil in 40-US-gallon (150 L) wooden barrels. But transport by barrel had several problems. The first problem

8000-612: The same mass at takeoff and landing. The logarithmic term with weight ratios is replaced by the direct ratio between W battery / W total {\displaystyle W_{\text{battery}}/W_{\text{total}}} R = E ∗ 1 g η total L D W battery W total {\displaystyle R=E^{*}{\frac {1}{g}}\eta _{\text{total}}{\frac {L}{D}}{\frac {W_{\text{battery}}}{W_{\text{total}}}}} where E ∗ {\displaystyle E^{*}}

8100-488: The scrap metal market. In 1998, almost 700 ships went through the scrapping process at shipbreakers in places such as Gadani , Alang and Chittagong . In 2004 and 2005, 7.8 million  DWT and 5.7 million  DWT respectively of oil tankers were scrapped. Between 2000 and 2005, the capacity of oil tankers scrapped each year has ranged between 5.6 million  DWT and 18.4 million  DWT . In this same timeframe, tankers have accounted for between 56.5% and 90.5% of

8200-469: The specific heat capacities of air at constant pressure and constant volume respectively. Or R = a M g c T C L C D ln ⁡ W 1 W 2 {\textstyle R={\frac {aM}{gc_{T}}}{\frac {C_{L}}{C_{D}}}\ln {\frac {W_{1}}{W_{2}}}} , also known as the Breguet range equation after

8300-566: The supply and demand of oil as well as the supply and demand of oil tankers. Some particular variables include winter temperatures, excess tanker tonnage, supply fluctuations in the Persian Gulf , and interruptions in refinery services. In 2006, time-charters tended towards long term. Of the time charters executed in that year, 58% were for a period of 24 or more months, 14% were for periods of 12 to 24 months, 4% were from 6 to 12 months, and 24% were for periods of less than 6 months. From 2003,

8400-713: The system is still used today. Besides that, there is the flexible market scale, which takes typical routes and lots of 500,000 barrels (79,000 m ). Merchant oil tankers carry a wide range of hydrocarbon liquids ranging from crude oil to refined petroleum products. 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. 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. The smallest tankers, with capacities under 10,000 DWT generally work near-coastal and inland waterways. Although they were in

8500-565: The tax authorities wanted evidence that the internal billing records were correct. Before the New York Mercantile Exchange started trading crude oil futures in 1983, it was difficult to determine the exact price of oil, which could change with every contract. Shell and BP , the first companies to use the system, abandoned the AFRA system in 1983, later followed by the US oil companies. However,

8600-629: The value of the local speed of sound. In this case: V = a M {\displaystyle V=aM} where M {\displaystyle M} is the cruise Mach number and a {\displaystyle a} the speed of sound . W is the weight. The range equation reduces to: R = a M g c T C L C D ∫ W 2 W 1 d W W {\displaystyle R={\frac {aM}{gc_{T}}}{\frac {C_{L}}{C_{D}}}\int _{W_{2}}^{W_{1}}{\frac {dW}{W}}} where

8700-461: The vessel hull instead of being loaded in barrels or drums. It was also the first tanker with a horizontal bulkhead; its features included cargo valves operable from the deck, cargo main piping, a vapor line, cofferdams for added safety, and the ability to fill a ballast tank with seawater when empty of cargo. The ship was built in Britain, and was purchased by Wilhelm Anton Riedemann, an agent for

8800-424: The voyage charter, the time charter, the bareboat charter , and contract of affreightment . In a voyage charter the charterer rents the vessel from the loading port to the discharge port. In a time charter the vessel is hired for a set period of time, to perform voyages as the charterer directs. In a bareboat charter the charterer acts as the ship's operator and manager, taking on responsibilities such as providing

8900-444: The width, or beam, of the ship. These holds were further subdivided into port and starboard sections by a longitudinal bulkhead. 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. But this approach of dividing the ship's storage space into smaller tanks virtually eliminated free-surface problems. This approach, almost universal today,

9000-401: The world's fleet in terms of deadweight tonnage. The world's total oil tankers deadweight tonnage has increased from 326.1 million  DWT in 1970 to 960.0 million  DWT in 2005. The combined deadweight tonnage of oil tankers and bulk carriers, represents 72.9% of the world's fleet. In 2005, 2.42 billion metric tons of oil were shipped by tanker. 76.7% of this was crude oil, and

9100-610: The world's total scrapped ship tonnage. In this period the average age of scrapped oil tankers has ranged from 26.9 to 31.5 years. In 2005, the price for new oil tankers in the 32,000–45,000  DWT , 80,000–105,000  DWT , and 250,000–280,000  DWT ranges were $ 43 million, $ 58 million, and $ 120 million respectively. In 1985 these vessels would have cost $ 18 million, $ 22 million, and $ 47 million respectively. Oil tankers are often sold second hand. In 2005, 27.3 million  DWT worth of oil tankers were sold used. Some representative prices for that year include $ 42.5 million for

9200-484: The world. In Worldscale negotiations, operators and charterers will determine a price based on a percentage of the Worldscale rate. The baseline rate is expressed as WS 100. If a given charter party settled on 85% of the Worldscale rate, it would be expressed as WS 85. Similarly, a charter party set at 125% of the Worldscale rate would be expressed as WS 125. The market is affected by a wide variety of variables such as

9300-713: Was carried. Similarly, each 1  DWT of oil tankers was responsible for 32,400 metric-ton miles of carriage. The main loading ports in 2005 were located in Western Asia, Western Africa, North Africa, and the Caribbean, with 196.3, 196.3, 130.2 and 246.6 million metric tons of cargo loaded in these regions. The main discharge ports were located in North America, Europe, and Japan with 537.7, 438.4, and 215.0 million metric tons of cargo discharged in these regions. International law requires that every merchant ship be registered in

9400-441: Was first used by Swan in the Nobel tankers Blesk , Lumen , and Lux . Others point to Glückauf , another design of Colonel Swan, as being the first modern oil tanker. It adopted the best practices from previous oil tanker designs to create the prototype for all subsequent vessels of the type. It was the first dedicated steam-driven ocean-going tanker in the world and was the first ship in which oil could be pumped directly into

9500-514: Was forward of the midships engine room and the other was aft. The ship also featured a set of 21 vertical watertight compartments for extra buoyancy . The ship had a length overall of 56 metres (184 ft), a beam of 8.2 metres (27 ft), and a draft of 2.7 metres (9 ft). Unlike later Nobel tankers, the Zoroaster design was built small enough to sail from Sweden to the Caspian by way of

9600-521: Was found during the war, the United States Coast Guard Marine Board of Investigation in 1952 stated that in cold weather the ships were prone to metal fatigue cracking, so were "belted" with steel straps. This occurred after two T2s, Pendleton and Fort Mercer , split in two off Cape Cod within hours of each other. Pendleton ' s sinking is memorialized in the 2016 film The Finest Hours . Engineering inquiries into

9700-598: Was nearly identical to the T2-SE-A1 version, except with 10,000 hp (7,500 kW) rather than 7,240. The A3 variation was essentially an A2 built as a naval oiler from the start, rather than converted later as many A2s were. Two of the A2 ships would be converted to the Pasig -class of distilling ships . Despite the confusing T3 designation, the T3-S-A1s built by Bethlehem Sparrows Point for Standard Oil of New Jersey were identical to

9800-491: Was renamed Happy Giant in 1989, Jahre Viking in 1991, and Knock Nevis in 2004 (when she was converted into a permanently moored storage tanker). In 2009 she was sold for the last time, renamed Mont , and scrapped . As of 2011, the world's two largest working supertankers are the TI-class supertankers TI Europe and TI Oceania . These ships were built in 2002 and 2003 as Hellespont Alhambra and Hellespont Tara for

9900-648: Was the world's largest flag state for oil tankers, with 528 of the vessels in its registry. 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). The Panamanian, Liberian, Marshallese and Bahamian flags are open registries and considered by the International Transport Workers' Federation to be flags of convenience . By comparison,

10000-540: Was weight: they weighed 29 kilograms (64 lb), representing 20% of the total weight of a full barrel. Other problems with barrels were their expense, their tendency to leak, and the fact that they were generally used only once. The expense was significant: for example, in the early years of the Russian oil industry, barrels accounted for half the cost of petroleum production. In 1863, two sail-driven tankers were built on England's River Tyne . These were followed in 1873 by

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