Crude oil tanker or product tanker too large to pass through the Panama Canal and below 120,000 dwt.

Anchor Handling Tug Supply. Offshore vessel used for jobs such as the relocation of oil rigs and anchors of the oil rigs.

American Petroleum Institute

API Gravity:
An arbitrary scale expressing the gravity or density of liquid petroleum products. The measuring scale is calibrated in terms of degrees API. The higher the API gravity, the lighter the compound. Light crudes generally exceed 38 degrees API and heavy crudes are commonly labeled as all crudes with an API gravity of 22 degrees or below.

Ash content of a fuel is a measure of the metal content in the fuel.

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Barrel (bbl):
A volumetric unit measure for crude oil and petroleum products equivalent to 42 U.S. gallons, or approximately 159 liters.

Break Horse Power. The amount of engine horsepower.

Bow thrusters:
Propeller in the front of the ship enabling it to turn sideways without forward momentum.

Brent Crude:
Term used for crude oil from the North Sea. Brent oil is traded at the International Petroleum Exchange in London, and the price of Brent is used as a benchmark for several other types of European oil.

Bulk vessel:
Description of vessels transporting large cargo quantities, including coal, iron ore, steel, grain, gravel, oil, etc.

Fuel for vessels

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Dry bulk carrier of more than approximately 80,000 dwt; too large to pass through the Panama Canal.

Cubic Meter.

Cetane Number, Cetane Index:
Cetane number and the cetane index are applicable primarily to gasoil and distillate fuels. The cetane number is a measure of the ignition/combustion quality of the fuel in a diesel engine. The higher the rpm of the engine, the higher the required cetane number. The cetane number of a fuel is determined in an engine test procedure. The cetane index is a calculated value, based on the density and the distillation of the fuel.

Car equivalent unit. Unit of measurement indicating the car carrying capacity of a vessel.

Compensated Gross Tonnage. International unit of measurement that facilitates a comparison of different shipyards' production regardless of the types of vessel produced.

Chemical tanker:
Tanker with coated or stainless steel tanks (IMO I-III).

Commercial Interest Reference Rate – for further details, see the OECD website.

Clean products:
Refers to light, refined oil products such as jet fuel, gasoline, diesel oil and naphtha.

Contract of Affreightment. Contract between shipping company and charterer concerning the freight of a predetermined volume of goods within a given period of time and/or at given intervals.

The internal coatings applied to the tanks of a product tanker. Coated tanks enable the ship to transport corrosive refined oil products and it facilitates extensive cleaning of the tanks, which may be required in the transportation of certain oil product types.

Container conference:
Collaboration agreement between a number of container shipping lines on trade routes or regions for the purpose of enhancing efficiency of the vessel capacity and harmonizing price/teu.

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Density is the weight of one litre of the fuel, at 15oC, expressed in kg. Density is used in the calculation of the quantity of the fuel delivered and invoiced to the customer. From a more technical viewpoint the density gives an indication of the heating value of a fuel within a certain product class.

Dirty products:
Refers to heavy oils such as crude oil or refined oil products such as fuel oil or bunker oil.

Dynamic Positioning. Special instruments on board that in conjunction with bow thrusters and main propellers enable the ship to position itself in a fixed position in relation to the seabed

Dead Weight Tons. International unit of measurement that indicates the loading capabilities in metric tonnes of the particular vessel, including the weight of crew, passengers, stores, bunkers etc.

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Small container carrier.


Flash Point:

Flash point is the temperature at which the vapours of a fuel ignite, under the specific conditions of the test, when an external ignition device (flame) is applied. For safety reasons, the minimum flash point for all fuels (with the exception of DMX) to be used onboard ships has been set at 60oC.



F(P)SO: Floating (Production) Storage Offloading Unit. Ship used as substitute for a conventional oil platform at oil fields that are either to deep in the ground or to small to justify the use of a conventional oil platform. If the ship is an FPSO the ship has oil (or gas) processing capabilities.

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Indicates that a vessel is equipped with a crane or other lifting device.

Indicates that a vessel is not equipped with a crane or other lifting device.

Volume weight ratio of a substance calculated against the same volume of water at normal temperature and pressure.

Gt:Gross Tons.
Unit of 100 cubic feet or 2.831 cubic meters, used in arriving at the calculation of gross tonnage.

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Handy tanker:
Crude oil tanker, product tanker or chemical tanker of between 10,000 and 25,000 dwt

Handymax, dry cargo:
Dry bulk carrier of between approximately 40,000 and 60,000 dwt.

Handysize, dry cargo:
Dry bulk carrier of between approximately 10,000 and 40,000 dwt.

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International Maritime Organization. {0>Søfartsorganistion under FN.<}96>A maritime organization under the UN,

Quality grades for tankers for the permission to transport different chemical and oil products. IMO I are the most hazardous products, IMO III the least hazardous.

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Kinematic Viscosity:
Kinematic viscosity of an oil is its resistance to flow at a specific temperature. The viscosity of a fuel decreases with increasing temperature. The viscosity of the fuel at the injectors has to be within the limits prescribed by the engine manufacturers. Incorrect viscosity at the injectors may lead to poor combustion, deposit formation and energy loss.

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LNG vessels:
Liquefied Natural Gas. Vessels for transporting liquefied natural gas (methane gas).

Lift on – Lift off. Cargo carrying vessel that has its cargo lifted on and/or off. This type of ship may also have passenger carrying capacity (Pax-Lo) and/or Ro-Ro features (Ro-Lo).

LPG vessels:
Liquefied Petroleum Gas. Vessels used to transport ammonia and liquid gases (ethane, ethylene, propane, propylene, butane, butylenes, isobutene and isobutylene).The gases are transported under pressure and/or refrigerated.

LR1, product tanker:
Long Range 1. Product tanker with the maximum dimensions for passing through the Panama Canal (width of 32.21 meters and length of 289.5 meters) of approximately 50,000—80,000 dwt.

LR2, product tanker:
Long Range 2. Product tanker too large to pass through the Panama Canal of approximately 80,000 dwt.Back to Top

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Million British Thermal Unit. Unit of measurement indicating the amount of energy included – equivalent to joule or calorie.

Medium, tanker (MR):
Medium Range. Product tanker of between 25,000 and 50,000 dwt.

Microcarbon Residue, Ramsbottom and Conradson Carbon Residue:
Microcarbon residue, ramsbottom and conradson carbon residue are three different test methods to check the same characteristic of a diesel fuel and a heavy fuel: the residue formed when the combustion takes place under reduced air supply. This residue contains incompletely burned fuel particles and also the ash formed by the fuel upon combustion.

Million Barrels of Oil Equivalent. Measure of the amount of barrels of oil/gas contained in a field.

Dry bulk carrier with multiple applications, mainly as a feeder vessel or for special cargo.

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Nautical Mile:
Distance unit measure of 1,852 meters, or 6,076.12 ft.

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Offshore vessel:
Vessel serving the offshore oil industry.
Organization of Petroleum Exporting Countries.

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Panamax, container:
Container carrier with the maximum dimensions for passing through the Panama Canal (width of 32.21 metres, length of 291 metres) of approximately 3,000—5,000 teu

Panamax, tanker:
Crude oil tanker or product tanker with the maximum dimensions for passing through the Panama Canal (width of 32.21 metres and length of 289.5 metres) of approximately 50,000—80,000 dwt.

Panamax, dry cargo:
Dry bulk vessel with the maximum dimensions for passing through the Panama Canal (width of 32.21 metres and length of 289.5 metres) of approximately 60,000—80,000 dwt.

Pure Car Carrier. Car carrier built exclusively to transport passenger cars.

Pure Car Truck Carrier. Car carrier built to transport small and large passenger cars (SUVs, MPVs, etc.), trucks and other contractor equipment.

Container vessel of approximately 4,000+ teu that is too large to pass through the Panama Canal.

Pour Point:
Pour point is the lowest temperature at which the fuel will pour or flow when chilled under prescribed test conditions. Bunker fuels originating from a complex refinery generally have pour points below 5 °C. This is reflected in the fact that bunker fuel is generally not completely heated anymore but only before the fuel transfer pump. If a vessel receives high-pour straight-run bunker fuel, heating of the fuel above the pour point temperature is required. Cold-temperature behaviour also can be important for marine distillate fuels.

Product tanker:
Tanker vessel with coated tanks used to transport refined oil products.

Platform Supply Vessel. Offshore vessel serving the offshore oil installations.

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Container vessel with cooling/freezing capacity.

Reefer vessel:
Bulk carriers with a large reefer capacity in the holds.

Ro-Ro vessel with container capacity

Ro-Ro vessel with passenger capacity.

Roll On – Roll Off. Common description of vessels on which the cargo is rolled on board and ashore.

ROV-Support Vessel:
Ship with Remotely Operated Vehicle (a robot) used e.g. to inspect underwater cables and pipes.

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Sediment by Extraction:
Sediment determination gives the amount of inorganic sediment (rust, sand) in the fuel (applicable only to DMB type marine diesel).

Silicon and Aluminum:
During one of the refining processes for the production of gasoline fractions, an aluminum silicate-type catalyst is used. Catalytic fines are often present in the heavy process streams from this operation, which are then used in blending IFOs. Fuel purification onboard vessels is an effective means of removing most of the silicon and aluminum particles from the IFOs.

Seismic Vessel:
Ship with on board sound and electromagnetic instruments for gauging the structure of the layers in the ground. The results are used as a tool to best decide where the oil and gas formations are located in the ground.

A semi-submersible is a self-propelled drilling rig, capable of lowering the well deck below the water's surface.

Stand-by vessel:
Offshore vessel used to monitor and fight fires and environmental accidents on oil rigs

Crude oil tanker with the maximum dimensions for passing through the Suez Canal (approximately 120,000—200,000 dwt.).

Sulphur is an inherent element of certain fuel molecules. Depending on the crude oil origin, the sulphur content of an IFO can easily vary from below 1.0% to above 4.0%. Sulphur is oxidized during combustion and produces oxides of sulphur which may lead to corrosive wear in the engine if the proper lubricants are not used.

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Twenty Feet Equivalent Unit. Container boxes with a length of 20 feet (about 6 metres) which forms the basis of describing the capacity of a container vessel.

Ton-nautical mile:
Unit of measurement indicating the volume of cargo and how far it has been transported

Synonymous with "vessel".

Total Potential Sediment:
Total potential sediment gives the total amount of sediment that can be formed under normal storage conditions, excluding external influences. Fuel oil stability is guaranteed if the total potential sediment meets the specification of 0.10 % max.

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Ultra Large Crude Carrier. Crude oil tanker above 320,000 dwt.

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Vanadium is one of the metals found in most crudes and fuel oils from these crude types. Some vanadium oxides formed during combustion, particularly in the presence of sodium, have critical melting temperatures that may lead to deposit formation in diesel engines turbochargers and boilers of steam turbine ships.

Approval procedure whereby e.g. the technical standards of a ship are surveyed.

Very Large Crude Carrier. Crude oil tanker of between approximately 200,000 and 320,000 dwt.

Very Large Gas Carrier. LPG ship with capacity above 60,000 cbm.

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Water content:
A small amount of water in fuel is a common contaminant and has to be removed by onboard purification of the fuel. An excessively high water content of the fuel after purification may lead to erratic engine operation.

West Texas Intermediate. Oil price benchmark in the USA.

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