A

Abandoned Well A well no longer in use, whether dry, inoperable or no longer productive, and the previous operator has intentionally relinquished its interest in the well.

Able bodied seaman A member of the deck crew who is able to perform all the duties of an experienced seaman. Also called Able Seaman and A.B.

Absolute Pressure Pressure above zero pressure; the sum of the gauge and atmospheric pressures.

Absorber A material that readily absorbs photons to generate charge carriers.

Absorbers Dark-colored objects that soak up heat in solar collectors.

Absorption coefficient The factor by which photons are absorbed as they travel a unit distance through a material.

Acre-Feet Unit of volume; one acre of producing formation one foot thick. One acre foot equals 7,758 barrels, 325,829 gallons or 43,560 cubic feet.

Acceptor A dopant material, such as boron, which has fewer outer shell electrons than required in an otherwise balanced crystal structure, providing a hole, which can accept a free electron.

Access Hole A hole through casing, bulkhead, floor or deck to enable one to reach work or gear.

Accommodation Barge vessel fitted with spacious, comfortable accommodation for deepwater offshore construction and accommodation projects. Se also barge.

Accommodation Ladder Stairs slung at the gangway. Accommodation Ladders are usually supplied with two platforms, one at each end. Sometimes called gangway ladder.

ACS, Alameda Corridor Sur Charge Sur Charge applied to IPI and MLB cargo moving via the Rail System where the port of Long Beach/Los Angeles is the Gateway.

Active power The component of electric power that performs work, typically measured in kilowatts (kW) or megawatts (MW).

Active solar heater A solar water or space-heating system that moves heated air or water using pumps or fans.

Accumulator (steam) A pressure vessel containing water and/or steam, which is used to store the heat of steam for use at a late period and at some lower pressure.

Acid Cleaning The process of cleaning the interior surfaces of steam generating units by filling the unit with dilute acid accompanied by an inhibitor to prevent corrosion, and subsequently draining, washing and neutralizing the acid by a further wash of alkaline water.

Acidity Represents the amount of free carbon dioxide, mineral acids and salts (especially sulphates of iron and aluminum) which hydrolyze to give hydrogen ions in water and is reported as milliequivalents per liter of acid, or ppm acidity as calcium carbonate, or pH the measure of hydrogen ions concentration.

Adiabatic A process in which heat is neither absorbed nor emitted.

Adiabatic Flame Temperature The theoretical temperature that would be attained by the products of combustion provided the entire chemical energy of the fuel, the sensible heat content of the fuel and combustion above the datum temperature were transferred to the products of combustion. This assumes: No heat loss to surroundings and no dissociation.

Adjustable speed drives Drives that save energy by ensuring the motor speed is properly matched to the load placed on the motor.

Adsorption The attraction exhibited by the surface of a solid for a liquid or a gas when they are in contact.

Affected employee An employee whose job requires him or her to operate or use a machine or equipment on which servicing or maintenance is being performed under lockout or tagout, or whose job requires him or her to work in an area in which such servicing or maintenance is being performed.

AFRAMAX oil tanker < 80,000 dwt.

Aft Near, or toward the stern of the vessel, ship.

After Peak A compartment just forward of the stern post. It is generally almost entirely below the load water line.

After Peak Bulkhead The bulkhead at the stern next to the after peak, always watertight.

After Perpendicular A vertical line at right angles to the base line at a point designated by the naval architect.

Agency Fee A fee charged to the ship by the ship's agent, representing payment for services while the ship was in port.

Air The mixture of oxygen, nitrogen, and other gases, which with varying amounts of water vapor, forms the atmosphere of the earth.

Air Atomizing Oil Burner A burner for firing oil in which the oil is atomized by compressed air, which is forced into and through one or more streams of oil which results in the breaking of the oil into a fine spray. Se also Oil burner Nozzles.

Air Circuit Breakers These are used to interrupt circuits while current flows through them. Compressed air is used to quench the arc when the connection is broken.

Air Condenser A surface condenser which uses the atmosphere for cooling.

Air Conditioning Cooling and dehumidifying the air in an enclosed space by use of a refrigeration unit powered by electricity.

Air Deficiency Insufficient air, in an air-fuel mixture, to supply the oxygen required for complete oxidation of the fuel.

Air Draught the distance from the water line to the upper most point on the vessel, usually the top of a mast or radar tower. The air draft of a vessel will vary depending upon the draft of the vessel and its trim.

Air Free The descriptive characteristic of a substance from which air has been removed.

Air Fuel Ratio The ratio of the weight, or volume, of air to fuel.

Air Source Heat Pump A type of heat pump that extracts heat from the outside air and brings it inside the building.

Air Infiltration The leakage of air into a setting or duct.

Air Mass The ratio of the mass of atmosphere in the actual observer-sun path to the mass that would exist if the observer was at sea level, at standard barometric pressure, and the sun was directly overhead. (sometimes called air mass ratio).

Air Pump A pump used to extract condensate (strictly just the air fraction) from a condenser of a steam plant.

Air Vent A valved opening in the top of the highest drum of a boiler or pressure vessel for venting air.

Air, Saturated Air which contains the maximum amount of water vapour that it can hold at its temperature and pressure.

AIS Automatic Identification System.

Alarm A suitable horn, bell, light or other device which when operated will give notice of malfunction or off normal condition.

Aldis lamp a lamp with focused beam used for signaling with the morse code and which can be seen at a distance of up to 20 miles.

Alkalinity Represents the amount of carbonates, bicarbonates, hydroxides and silicates or phosphates in the water and is reported as grains per gallon, or ppm as calcium carbonate.

Allowable Working Pressure See design pressure.

Alongside A phrase referring to the side of a ship. Goods delivered "alongside" are to be placed on the quay, dock or barge within reach of the transport ship's tackle so that they can be loaded.

Alternating current AC Electric current in which the direction of flow is reversed at frequent intervals: usually 100 or 120 times per second (50 or 60 cycles per second or 50 / 60 Hz).

Alternative fuel Alternative fuels, for transportation applications, include the following: Coal derived liquid fuels, denatured ethanol, and other alcohols, fuel mixtures containing 85 percent or more by volume of methanol, denatured ethanol, and other alcohols with gasoline or other fuels, hydrogen, LPG liquefied petroleum gas (propane), methanol, fuels (other than alcohol) derived from biological materials.

Alternative fuels Solid fuels such as municipal solid waste (MSW), refuse derived fuel (RDF), biomass and other combustibles that are used instead of fossil fuels (gas, oil, or coal) in a boiler to produce steam for the generation of electrical energy.

Always Afloat (AA) Always Afloat (In some ports the ship aground when approaching, or at berth)

Ambient Air The air that surrounds the equipment. The standard ambient air for performance calculations is air at 80 °F, 60% relative humidity, and a barometric pressure of 29.921 in. Hg, giving a specific humidity of 0.013 lb of water vapor per lb of dry air or 1.013 bar and a temperature of 15°C (ISO).

Ambient Temperature The temperature of the air surrounding the equipment.

Amidships Means in the middle portion of a vessel.

Ammeter An electric meter used to measure current, calibrated in amperes.

Ampacity The current-carrying capacity of conductors or equipment, expressed in amperes.

Ampere (A) or amp The basic SI unit measuring the quantity of electricity. The unit for the electric current; the flow of electrons. One amp is 1 coulomb passing in one second. One amp is produced by an electric force of 1 volt acting across a resistance of 1 ohm.

Ampere-hour (Ah) Quantity of electricity or measure of charge. (1 Ah = 3600 C [Coulomb])

Amorphous semiconductor A non-crystalline semiconductor material that has no long-range order.

Analysis Quantitative determination of the constituent parts.

Analysis, Ultimate Chemical analysis of solid, liquid or gaseous fuels. In the case of coal or coke, determination of carbon, hydrogen, sulfur, nitrogen, oxygen, and ash.

Anchor Handling Tug

Anchor winch equipment for a ship, a yacht or a small boat, which ensures easy and simple paying out and hauling in an anchor from the ocean, and whose power is supplied from hydraulic, generator or a battery provided in said ship, yacht or vessel. Se also capstan winch, deck equipment.

Angle of Advance The angle in excess of 90o by which the eccentric leads the crank (assuming an outside-admission slide valve).

Angle Bar A bar "L" shaped, or two flanges at 90 degrees.

Angle Collar Circular angular section fastened around a column to hold the column to the deck.

Annual solar savings The annual solar savings of a solar building is the energy savings attributable to a solar feature relative to the energy requirements of a non-solar building.

Annual Survey The inspection of a ship pursuant to international conventions, by a classification society surveyor, on behalf of the flag state, that takes place every year. Se also classification society, flag state.

Anthropogenic Referring to alterations in the environment due to the presence or activities of humans.

Anthracite The highest rank of coal, used primarily for residential and commercial space heating. The heat content of anthracite ranges from 22 to 28 million Btu per ton.

Antireflection coating A thin coating of a material, which reduces the light reflection and increases light transmission, applied to a photovoltaic cell surface.

API Gravity The standard adopted by API for measuring the density of a liquid, expressed in degrees. The measuring scale is calibrated in terms of degrees API, it is calculated as follows: Degrees API = (141.5 / sp.gr.60 deg.F/60 deg.F) - 131.5.

Apparent power The product of the voltage in volts and the current in amperes. It comprises both active and reactive power. It is measured in volt-amperes and often expressed in kilovolt-amperes kVA or megavolt-amperes MVA.

Apron Plate A small plate on forecastle deck to cover stem, sometimes used to support a chock.

Aquastat Water limit temperature control, a safety device often used on boilers.

Armored Cable A cable provided with a wrapping of metal, usually steel wires or tapes, primarily for the purpose of mechanical protection.

Arc over Voltage The minimum voltage required to cause an arc between electrodes separated by a gas or liquid insulation.

Array Any number of photovoltaic modules connected together to provide a single electrical output. Arrays are often designed to produce significant amounts of electricity.

Arrester A device to impede the flow of large dust particles or sparks from a stack, usually screening at the top.

Articles Of Agreement The document containing all particulars relating to the terms of agreement between the master of the vessel and the crew (ship's articles).

As Fired Fuel Fuel in the condition as fed to the fuel burning equipment.

As Received Fuel Fuel in the condition as received at the plant.

Ash The incombustible inorganic matter in the fuel.

Ash Pit A pit or hopper located below a furnace where refuse is accumulated and from which refuse is removed at intervals.

Ash Free Basis The method of reporting fuel analysis, whereby ash is deducted and other constituents are recalculated to total 100%.

Associated dissolved natural gas Natural gas that occurs in crude oil reservoirs either as free gas or as gas in solution with crude oil.

Aspirating Burner A burner in which the fuel in a gaseous or finely divided form is burned in suspension, the air for combustion being supplied by bringing into contact with the fuel, air drawn through one or more openings by the lower static pressure created by the velocity of the fuel stream.

Astern Backward direction in the line of a vessel's fore and aft line, behind.

Atmospheric Air Air under the prevailing atmospheric conditions.

Atmospheric crude oil distillation The refining process of separating crude oil components at atmospheric pressure by heating to temperatures of about 315 degrees to 400 degrees Celsius (depending on the nature of the crude oil and desired products) and subsequent condensing of the fractions by cooling.

Atmospheric Pressure The barometric reading of pressure exerted by the atmosphere. At sea level 14.7 lb per sq in. or 29.92 in. of mercury or 101.325 kPa (1013.25 mbar).

Atomizer A device by means of which a liquid is reduced to a very fine spray.

Attendant An employee assigned to remain immediately outside the entrance to an enclosed or other space to render assistance as needed to employees inside the space.

Attenuation (1)The ratio of the input to output power levels in a network (transmission line) when it is excited by a matched source and terminated in a matched load. (2) Power loss in an electrical system.

Authorized employee An employee who locks out or tags out machines or equipment in order to perform servicing or maintenance on that machine or equipment. An affected employee becomes an authorized employee when that employee's duties include performing servicing or maintenance covered under this section.

Automatic circuit re closer A self-controlled device for interrupting and re-closing an alternating current circuit with a predetermined sequence of opening and re-closing followed by resetting, hold-closed, or lockout operation.

Automatic Pilot An instrument designed to control automatically a ship's steering gear so that it follows a pre-determined track through the water (tiller pilot).

Automation The automatic, self regulating control of equipment, systems, or processes.

Auxiliary Foundations The supports for pumps, condensers, distillers, compressor etc.

Auxiliary generator A generator at the electric plant site that provides power for the operation of the electrical generating equipment itself, including related demands such as plant lighting, during periods when the electric plant is not operating and power is unavailable from the grid.

Auxiliary Machinery The various pumps etc. used to support the main engine(s), boiler(s).

Availability Describes the reliability of power plants. It refers to the number of hours the turbines are available to produce power divided by the total hours in a year.

Availability Factor The fraction of time during which the unit is in operable condition.

Available Draft The draft which may be utilized to cause the flow of air for combustion or the flow of products of combustion.

Average stream flow The rate, usually expressed in liter per second, at which water passes a given point in a stream over a set period of time.

AW, AWR, AWS All Water Service Imported traffic moving to a destination port where the sea vessel is the only mode of transport.

Axial Fan Consists of a propeller or disc type of wheel within a cylinder that discharges air parallel to the axis of the wheel.