CAM: A rotating component of irregular shape. It is used to change direction of the motion of another part moving against it. (For example, rotary motion is changed into reciprocating or variable motion.)

CAM FOLLOWER (VALVE LIFTER): A part that is held in contact with the cam and to which the cam motion is imparted and transmitted to the push rod.

CAM NOSE: That portion of the cam that holds the valve wide open. It is the high point of the cam.

CAMSHAFT: A shaft with cam lobes.

CAMSHAFT GEAR: The gear that is fastened to the camshaft.

CAPACITOR: An arrangement of insulated conductors and dielectrics for the accumulation of an electric charge with small voltage output.

CARBURETOR: An apparatus for supplying atomized and vaporized fuel mixed with air to an internal-combustion engine.

CARRYOVER: (1) Boiler water entrained with the steam (by foaming or priming). (2) Particles of seawater trapped in vapor in a distilling plant and carried into the condensate.

CASING: A housing that encloses the rotating element (rotor) of a pump or turbine.

CASING THROAT: An opening in a turbine or pump casing through which the shaft protrudes.

CASUALTY: An event or series of events in progress during which equipment damage and/or personnel injury has already occurred. The nature and speed of these events are such that proper and correct procedural steps are taken to limit damage and/or personnel injury only.

CASUALTY POWER SYSTEM: Portable cables that are rigged to transmit power to vital equipment in an emergency.

CATALYST: A substance used to speed up or slow down a chemical reaction, but is itself unchanged at the end of the reaction.

CELSIUS: The temperature scale with a freezing point of 0 and a boiling point of 100, with 100 equal divisions (degrees) between. This scale was formerly known as the centigrade scale.

CENTRIFUGAL FORCE: A force exerted on a rotating object in a direction outward from the center of rotation.

CETANE VALUE: A measure of the ease with which diesel fuel will ignite.

CHECK VALVE: A valve which permits fluid flow in one direction, but prevents flow in the reverse direction.

CHEMICAL ENERGY: Energy stored in chemicals (fuel) and released during combustion of the chemicals.

CHLORIDE: A compound of the chemical element chlorine with another element or radical.

CIRCUIT: An arrangement of interconnected electrical components that offers a route for current between the two points of the power source.

CIRCUIT BREAKER: An electromagnetic or thermal device that opens a circuit when the current in the circuit exceeds a predetermined amount. Circuit breakers can be reset.

CIRCULATING WATER: Water circulating through a heat exchanger (condenser or cooler) to transfer heat away from an operating component.

CLARIFIER: A water tank containing baffles that slow the rate of water flow sufficiently to allow heavy particles to settle to the bottom and light particles to rise to the surface. This separation permits easy removal, thus leaving the clarified water. The clarifier is sometimes referred to as a settling tank or sedimentation basin.

CLOSED COOLING SYSTEM: Consisting of two entirely separate circuits-a freshwater circuit and a seawater circuit.

CLUTCH: A form of coupling that connects or disconnects a driving or driven member.

COMMUTATOR: The copper segments on the armature of a motor or generator. It is cylindrical in shape and is used to pass power into or from the brushes.

COMPRESSION STROKE: That stroke of the operating cycle during which air is compressed into a smaller space creating heat by molecular action.

COCK: A valve that is opened or closed by a quarter turn of a disk or a tapered plug. When a plug is used, it is slotted to correspond with the ports in the valve.

COLD IRON CONDITION: An idle plant, when all services are received from an external source such as shore or tender.

COMBUSTION: The burning of fuel in a chemical process accompanied by the evolution of light and heat.

COMBUSTION AIR: The air delivered to a boiler furnace, engine, or gas turbine combustor to support burning of atomized fuel.

COMBUSTION CHAMBER: The chamber in which combustion mainly occurs.

COMBUSTION-CHAMBER VOLUME: The volume of the combustion chamber (when the piston is at TDC) measured in cubic centimeters.

COMBUSTION CYCLE: A series of thermo-dynamic processes through which the working gas passes to produce one power stroke. The full cycle is-intake, compression, power, and exhaust.

COMPENSATING DEVICE: Mechanical or hydraulic action which prevents overcorrection of change.

COMPONENT: Individual unit, or part, of a system; also, the major units which, when suitably connected, comprise a system.

COMPRESSION RING: The piston rings used to reduce combustion leakage to a minimum.

CONDENSATE: In a distilling plant, the product resulting from the condensation of steam (vapor) produced by the evaporation of seawater. Condensate may also be referred to by different names such as freshwater, freshwater distillate, or distillate.

CONDENSATE DEPRESSION: The dif-ference between the temperature of condensate in the condenser hotwell and the saturation temperature corresponding to the vacuum maintained in the condenser.

CONDENSATION: The change from a gaseous (or vapor) state to a liquid state.

CONDENSER: A heat transfer device in which vapor is condensed to liquid.

CONDUCTANCE: The ability of a material to conduct or carry electrical or thermal energy. Electrical conductance is the reciprocal of the resistance of the material and is expressed in mhos.

CONDUCTION: Heat transfer by actual contact between substances or from molecule to molecule within a substance.

CONDUCTIVITY: The ease with which a substance transmits electricity.

CONDUCTOR: Any material suitable for carrying electric current.

CONSOLE: A panel equipped with remote manual controls and visual indicators of system performance.

CONTROL AIR SUPPLY: Clean, dry air at proper pressure for operation of pneumatic control equipment.

CONTROLLER (electrical): A device used to stop, start, and protect motors from overloads while they are running.

COOLER: Any device that removes heat. Some devices, such as oil coolers, remove heat to waste in overboard seawater discharge; other devices, such as ejector coolers, conserve heat by heating condensate for boiler feed-water.

COOLING SYSTEM: Heat removal process that uses mechanical means to remove heat to maintain the desired air temperature. The process may also result in dehumidification.

CORROSION: A gradual wearing away or alteration of metal by a chemical or electro-chemical process. Essentially, it is an oxidizing process, such as the rusting of iron by the atmosphere.

COTTER, PIN, SPRING: A round split pin used to position and secure a nut on a bolt. The pin is passed through a hole in the nut and bolt. The ends of the pin opposite its head are forced apart by a screwdriver, pliers, or similar tool, thus preventing the cotter from slipping out.

COUNTERBALANCE: A weight, usually attached to a moving component, that balances another weight.

COUNTERBORE: (1) The enlargement of the end of a hole for receiving and recessing the head of a screw or bolt below or flush with the surface. (2) A tapered enlargement at the end of an engine cylinder to reduce ridging by the pistonstop compression ring.

COUNTERSUNK HOLE: A hole tapered or beveled around its edge to allow a rivet or bolt head or a rivet point to seat flush with or below the surface of the riveted or bolted object.

COUNTERWEIGHT: Weights that are mounted on the crankshaft opposite each crank throw. These weights reduce the vibration caused by putting the crank in practical balance and also reduce bearing loads due to inertia of moving parts.

COUPLING: A device for securing together adjoining ends of piping, shafting, and so forth, in such a manner to permit disassembly whenever necessary.

CRANE: A machine used for hoisting and moving pieces of material or portions of structures or machines that are either too heavy to be handled by hand or cannot be handled economically by hand.

CRANKCASE: The part of an engine frame which serves as a housing for the crank-shaft.

CRANKCASE SCAVENGING: Scavenging method that uses the pumping action of the power piston in the crankcase to pump scavenging air.

CRANKPIN: The portion of the crank throw attached to the connecting rod.

CRANKSHAFT: A rotating shaft for con-verting rotary motion into reciprocating motion.

CRANKSHAFT GEAR: The gear that is mounted to the crankshaft.

CRANK THROW: One crankpin with its two webs (the amount of offset of the rod journal).

CRANK WEB: The portion of the crank throw between the crankpin and main journal. This makes up the offset.

CREEP-RESISTANT ALLOY: A metal which resists the slow plastic deformation that occurs at high temperatures when the material is under constant stress.

CREST: The surface of the thread cor-responding to the major diameter of an external thread and the minor diameter of an internal thread.

CRITICAL SPEED: The speed at which natural torsional vibrations of a crankshaft tend to reinforce themselves, causing vibration and potentially destructive stresses.

CROSS-CONNECT: To align systems to provide flow or to exchange energy between machinery groups.

CROSS-CONNECTED PLANT: A method of operating two or more plants as one unit from a common supply.

CYCLE: An interval of time during which a sequence of a recurring succession of events is completed.

CYLINDER: A solid figure with two circular bases. A hollow tube which contains the actions of combustion gases and the piston in an internal-combustion reciprocating engine.

CYLINDER BLOCK: A rigid unit of the engine frame which supports the engines cylinderliners and heads. A cylinder block may contain passages to allow circulation of cooling water and drilled lube oil passages.

CYLINDER LINER: A sleeve which is inserted in the bores of the engine block which make up the cylinder wall.