F

The cutting, forming, and welding of steel and other materials into the parts and units that make up a ship's structure.

The workshop in a shipyard where steel is cut, shaped, and assembled into structural units before erection.

The permitted deviation from nominal dimensions in fabricated parts, within which the work is acceptable.

The flat plate forming the free edge (flange) of a built-up girder or stiffener, carrying much of the bending load.

Designed so that a failure leaves the system in a safe state, for example a valve that closes or an alarm that activates on loss of power or signal.

A systematic technique for identifying the ways a system can fail and the effects of each failure, used to assess and improve reliability and safety, for example of dynamic-positioning systems.

A grading or rating term used in coating-condition assessment to describe a moderate state between good and poor.

A fitting that guides a mooring or towing line in a controlled direction and reduces chafe as it leads over the ship's side.

A navigable channel or route through which vessels pass, often marked and maintained for safe passage.

The speed appropriate or permitted for a vessel navigating a fairway, having regard to safety and any local limits.

The rope or wire rove through the blocks of a davit or tackle by which a boat or load is hoisted and lowered.

Devices fitted to lifeboat release gear to prevent accidental release and the fall of the boat during drills and maintenance, addressed in IMO measures to prevent lifeboat accidents. IMO-grounded

A vessel that places rock precisely on the seabed through a flexible fallpipe, used to protect pipelines and subsea structures.

The ropes or wires of a davit or tackle used to raise and lower boats; see fall.

A machine that moves air for ventilation, combustion, or cooling.

High-speed passenger or vehicle ferries, often of catamaran or other advanced form, which when meeting the criteria are governed by the High-Speed Craft Code under SOLAS. IMO-grounded

A unit of water depth equal to six feet (about 1.83 metres).

The progressive weakening and cracking of a material under repeated cyclic loading, a major cause of structural cracking in ships' hulls and details.

A crack that initiates and grows under repeated loading, eventually leading to failure if not detected and repaired.

The ability of a material or detail to withstand a number of load cycles without fatigue failure.

The number of load cycles, or the time in service, that a structural detail can sustain before a fatigue crack develops.

The stress level below which a material can theoretically endure an unlimited number of load cycles without fatigue failure.

The stress a material or detail can withstand for a specified number of load cycles without failing by fatigue.

A non-return valve through which feed water enters a boiler, preventing reverse flow from the boiler back into the feed line.

A heat exchanger that warms boiler feed water before it enters the boiler, improving cycle efficiency.

The water supplied to a boiler to be turned into steam, which must be treated to control scale and corrosion.

The chemical conditioning of boiler feed water to remove oxygen and control hardness and pH, protecting the boiler from scale and corrosion.

A short-sea shipping service that carries containers between a hub port and smaller regional ports, connecting with deep-sea services.

Vertical trunks above a grain hold that keep it topped up with grain as the cargo settles, reducing the free surface that could let the cargo shift; their use is addressed in the International Grain Code. IMO-grounded

A set of thin metal blades of known thickness used to measure small gaps and clearances.

A cushioning device hung over the side or fitted to a quay to absorb impact and protect the hull during berthing.

The extent of the view available from a position such as the bridge; minimum fields of vision from the navigating bridge are required by SOLAS. IMO-grounded

The metal added from an electrode or wire to fill a welded joint.

A weld of roughly triangular cross-section joining two surfaces meeting at an angle, the most common type of weld in shipbuilding.

A thin continuous layer, such as the film of a paint coating or of lubricating oil between bearing surfaces.

The thickness of an applied coating film, measured wet or dry, important for achieving the specified protection.

A device that removes solid particles or contaminants from a fluid passing through it.

A filter that can be cleaned by reversing the flow to wash accumulated dirt off the element, allowing continued service without dismantling.

The removal of suspended solids from a fluid by passing it through a filter medium.

A small subdivision of a structure used in numerical stress analysis, the building block of the finite element method.

A numerical technique that divides a structure into many small elements to compute stresses and deflections under load, widely used in ship structural design.

Uncontrolled combustion, one of the most serious hazards aboard ship, against which extensive prevention, detection, and extinguishing measures are required under SOLAS chapter II-2. IMO-grounded

A plan, required by SOLAS, permanently displayed and stored for shore responders, showing the fire-control stations, fire-resisting divisions, alarms, detection and extinguishing systems, and means of escape. IMO-grounded

A device that senses the presence of fire, by heat, smoke, or flame, and triggers an alarm, forming part of the fixed fire-detection system required under SOLAS and the FSS Code. IMO-grounded

The piping system that supplies seawater under pressure to the fire hydrants and equipment around the ship, fed by the fire pumps and required under SOLAS. IMO-grounded

A high-capacity directional nozzle, fixed or trainable, that projects a powerful jet of water or foam onto a fire, used for example on fire-fighting vessels and for protecting cargo areas.

A regular patrol of the ship to detect any outbreak of fire early, required on passenger ships under SOLAS in areas not covered by fixed detection. IMO-grounded

The pumps that supply pressurised water to the fire main; their number, capacity, and arrangement, including an emergency fire pump, are required under SOLAS. IMO-grounded

The IMO FSS Code, mandatory under SOLAS, giving the detailed technical requirements for the fire-safety systems referred to in SOLAS chapter II-2. IMO-grounded

Protective clothing forming part of a fireman's outfit, providing protection against heat and flame for fire-fighting, as required under SOLAS. IMO-grounded

The IMO FTP Code, mandatory under SOLAS, prescribing the test methods used to approve materials and divisions for fire safety, such as non-combustibility and fire-resistance tests. IMO-grounded

A fire-resisting division that limits the spread of fire from one area to another.

A wire rope rigged over the side of a tanker at a berth so that a tug can quickly tow the ship away from the jetty in an emergency.

Portable and fixed appliances charged with water, foam, dry powder, or gas for extinguishing fires; their types, numbers, and placement are governed by SOLAS and the FSS Code. IMO-grounded

In some manning structures, the senior engineer officer under the chief engineer, equivalent to the second engineer.

The deck officer next in rank to the master, head of the deck department; see chief mate.

The first mooring line passed and secured ashore when berthing, used to begin controlling the ship alongside.

A synthetic liquid fuel produced from gas or other feedstock by the Fischer-Tropsch process, of interest as a cleaner-burning marine fuel.

A government vessel used to enforce fishing regulations, inspect fishing vessels, and protect fishery resources.

The nets, lines, traps, winches, and other equipment used aboard a fishing vessel to catch and handle fish.

The various techniques used to catch fish, such as trawling, purse seining, longlining, and potting, which influence vessel design.

Vessels used commercially to catch fish and other living marine resources; their safety is addressed by dedicated IMO instruments such as the Torremolinos regime and STCW-F. IMO-grounded

Fittings permanently attached to the structure, such as the fixed cargo-securing points provided for containers and other cargo.

A drive arrangement using a fixed chain along which a powered unit hauls itself, used in some specialised handling systems.

A proprietary fixed pad or seating used in container or cargo securing arrangements.

The registration of a ship in a country other than that of its owners, typically to take advantage of that flag's regulations, taxes, or crewing rules.

The detachment of a coating from the surface in flakes, a mode of coating breakdown that exposes the steel to corrosion.

A device fitted in a vent or pipe that allows gas to pass but stops a flame from travelling through it, preventing a fire or explosion from spreading into a tank; required in tanker venting arrangements. IMO-grounded

A fire detector that senses the radiation emitted by flames, giving rapid detection of an open fire.

Substances that suppress or interrupt combustion, used in some fire-extinguishing agents.

A fitted screen of corrosion-resistant wire mesh that prevents the passage of flame into a tank vent or opening while allowing gas to pass. IMO-grounded

The speed at which a flame front travels through a combustible mixture.

A device, similar to a flame arrester, that stops flame propagation through an opening or passage.

Describing electrical equipment enclosed so that it will not ignite a surrounding flammable atmosphere, required for hazardous areas; see explosion-proof. IMO-grounded

The lower and upper concentrations of a flammable vapour in air between which the mixture will ignite; outside these limits it is too lean or too rich to burn.

A liquid or gas that can readily ignite and burn, requiring control of ignition sources and, on tankers, of the tank atmosphere. IMO-grounded

Capable of catching fire and burning readily.

A light that shows regular flashes, used as a navigation light characteristic or for signalling.

The lowest temperature at which a liquid gives off enough vapour to form an ignitable mixture with air; it is the key measure of a liquid's fire hazard and is used in classifying cargoes and fuels under SOLAS and the cargo codes. IMO-grounded

A partial deck or platform within a space; also the flat position of welding.

The downhand welding position, in which welding is done from above on a horizontal surface, the easiest and most productive position.

The angle at which a wire leads onto a winch drum or sheave; keeping it within limits ensures the wire spools correctly without damage.

A rotating vertical cylinder that generates thrust from the wind by the Magnus effect, fitted to some ships as a wind-assisted propulsion device to save fuel.

A coupling that connects two shafts while accommodating slight misalignment and damping torsional vibration.

A proprietary flexible pad used in cargo or equipment securing arrangements.

A proprietary flexible sealing product, for example for shaft or hatch sealing.

A method by which a survival craft or appliance floats free and deploys automatically as the ship sinks, without manual launching; required for certain equipment under SOLAS and the LSA Code. IMO-grounded

The ability of a body to float, depending on its weight relative to the buoyancy it can develop.

Floating barriers deployed on the water to contain or deflect an oil spill, part of pollution-response equipment.

Crane-equipped vessels or pontoons used for heavy lifts in harbours and offshore.

A floating structure, such as a production or storage unit, kept on station to perform offshore functions rather than to navigate.

A vessel used to install floating offshore structures and equipment.

The use of a floating vessel or unit to store crude oil or products offshore, such as an FSO.

A floating offshore facility that processes oil and gas from subsea wells, often combined with storage and offloading.

A vessel-shaped floating facility used to produce and process hydrocarbons offshore.

Floating offshore units that receive, process, store, and offload oil and gas from subsea wells, widely used in offshore fields.

A floating offshore unit used to store and offload crude oil or products, without significant processing.

The gathering of fine suspended particles into larger clusters so they can be separated more easily, used in water and fuel treatment.

Doors that can be closed to limit the spread of flooding within the ship, contributing to damage survivability. IMO-grounded

The maximum length of a compartment that can be flooded without the ship sinking below its margin line, a basis of subdivision under SOLAS. IMO-grounded

The entry of water into the hull, whether accidental after damage or deliberate (cross-flooding), the control of which is central to damage stability. IMO-grounded

A transverse vertical plate in the bottom structure, running from the keel to the bilge, that supports the inner bottom and stiffens the bottom.

A ballast-water exchange method in which clean water is pumped into a full tank so that it overflows, replacing the original water to meet the D-1 standard of the BWM Convention. IMO-grounded

A heat exchanger that recovers heat from boiler or engine flue gas to preheat feed water, improving efficiency.

The system that conveys and may treat the combustion gases from boilers or engines, including any heat recovery and cleaning.

A flue-gas-based inert-gas arrangement supplemented by a generator that tops up the inert gas supply when boiler flue gas is insufficient.

A substance that flows, that is, a liquid or a gas.

An open or partly filled tank in which liquid can move to damp a ship's roll, a form of anti-roll tank.

A ship with a continuous upper deck running unbroken from bow to stern, without a raised forecastle, bridge, or poop.

An arc welding process using a tubular electrode filled with flux, giving high deposition rates and suiting shipyard production.

A heavy rotating wheel that stores rotational energy and smooths out variations in an engine's speed between power strokes.

The concentrated liquid that is mixed with water to make the solution used to generate fire-fighting foam.

Fixed or portable systems that generate and apply foam to extinguish flammable-liquid fires by smothering them; required for tankers and certain spaces under SOLAS and the FSS Code. IMO-grounded

A fender filled with resilient foam rather than air, which continues to protect even if its outer skin is punctured.

The mixture of water and foam concentrate that is aerated to produce fire-fighting foam.

The arrangement of tanks, proportioners, piping, and monitors or applicators that delivers fire-fighting foam, as required for protecting tanker decks and other spaces. IMO-grounded

A mass of bubbles used to extinguish fires by forming a blanket that smothers the flames and seals the fuel surface.

A hatch or other cover made of panels that fold together to open, saving space.

Hatch covers made of hinged panels that fold up to open the hatch, operated hydraulically.

A proprietary integrated computer-aided ship design and production software system.

A push or pull that tends to change the motion or shape of a body.

A contractual clause excusing a party from performance when prevented by extraordinary events beyond its control, such as natural disasters or war.

In a power converter, the use of additional circuitry to turn off a switching device, as distinct from natural (line) commutation.

The compartment at the extreme bow, forward of the collision bulkhead, usually used as a ballast tank.

In the direction of the ship's length, from bow to stern, as opposed to athwartship.

The raised structure at the bow of a ship, providing buoyancy and protection forward and housing stores and machinery.

The deck of the forecastle, the short raised deck at the bow.

The lower part of the bow where the stem meets the keel.

Cargoes such as timber, logs, packaged lumber, and paper, which require particular stowage and securing; the carriage of timber deck cargoes is addressed by an IMO code of practice. IMO-grounded

The shaping of metal by hammering or pressing, producing strong components with favourable grain flow, used for items such as crankshafts and shafting.

The path or deck strengthened for the operation of forklift trucks during cargo handling.

A structured, risk-based methodology used by the IMO to evaluate proposed safety regulations by weighing risks and the costs and benefits of options. IMO-grounded

Toward the bow of the ship.

A vertical reference line at the point where the design waterline crosses the stem, defining the forward limit of the length between perpendiculars.

The region where the hull's parallel middle body curves outward toward the bow at the waterline.

Fuel derived from ancient organic matter, such as oil, coal, and natural gas, the combustion of which produces the greenhouse gases now being regulated for shipping. IMO-grounded

The situation in which the anchor cable becomes entangled, for example around the anchor itself or an obstruction on the seabed.

The fouling of a propeller by ropes, nets, or other debris that wrap around it and impede or stop it.

The accumulation of marine organisms or deposits on a surface, especially the underwater hull, increasing resistance and fuel consumption; controlled by anti-fouling systems.

An internal-combustion engine that completes its cycle in four piston strokes (intake, compression, power, exhaust) over two revolutions, common for medium-speed marine engines and generators.

The breaking of a material into pieces under load, which may be ductile or brittle.

A transverse structural member of the hull, like a rib, that supports the side shell plating and helps maintain the ship's form.

The distance between adjacent frames, a basic parameter of the structural design.

The arrangement of a ship's structural members, which may be transverse, longitudinal, or a combination, chosen to suit the ship type and loads.

The acceleration experienced by occupants of a free-fall lifeboat as it enters the water, which must be kept within safe limits in the design and certification. IMO-grounded

The launch height for which a free-fall lifeboat is certified, demonstrating safe occupant accelerations and water entry. IMO-grounded

A launching method in which a lifeboat slides down a ramp and drops into the sea under gravity, achieving rapid clearance of the ship; governed by SOLAS and the LSA Code. IMO-grounded

A lifeboat designed to be launched by free fall from a stern ramp, providing fast evacuation; required and tested to standards in SOLAS and the LSA Code. IMO-grounded

The uncontrolled fall of liquid within a tank or system, which can cause surging loads and static build-up; avoided by proper filling arrangements.

The vertical distance from the waterline to the freeboard deck at the side, representing the reserve buoyancy; minimum freeboard is set by the International Convention on Load Lines. IMO-grounded

Generally the uppermost continuous deck exposed to weather and sea, with permanent means of closing all openings below it, from which freeboard is measured under the Load Line Convention. IMO-grounded

The load line marking on the ship's side indicating the maximum permitted draughts, assigned under the Load Line Convention; see also Plimsoll mark. IMO-grounded

The plan showing the assigned freeboards, load line marks, and the arrangements on which they depend, prepared for load-line assignment. IMO-grounded

An opening in the bulwark that allows water shipped on deck to drain quickly back to the sea, the area of which is required by the Load Line Convention. IMO-grounded

The temperature at which a liquid turns to solid.

The charge paid for the carriage of cargo by sea, or the cargo itself.

A trade name for chlorofluorocarbon refrigerants, now largely phased out under environmental rules because of their ozone-depleting and greenhouse effects. IMO-grounded

The number of cycles per unit time of a periodic quantity, such as the frequency of the ship's alternating-current supply.

An electrical drive that varies the frequency supplied to a motor to control its speed, used for example in electric propulsion and large pumps.

Equipment that produces fresh water from seawater aboard ship, typically by evaporation using waste heat, or by reverse osmosis.

Contact between surfaces that undergo small repeated relative movement, which can lead to fretting wear and corrosion.

Damage occurring at the contact between surfaces subject to small oscillatory movement, combining wear and corrosion, found at clamped or bolted joints.

Failure of a component caused by fretting, in which small repeated movements at a contact initiate wear and fatigue cracks.

Corrosion accelerated by frictional movement between surfaces; see fretting corrosion.

A dimensionless number relating a ship's speed to its length, governing the wave-making behaviour and used to scale resistance from model to ship.

A power unit that generates electricity by the electrochemical reaction of a fuel such as hydrogen with oxygen, offering efficient, low-emission power, being developed for marine use.

A packaged unit that prepares fuel, for example liquefied gas, to the temperature, pressure, and condition required by the engine.

The oil burned in a ship's engines and boilers; its quality and, in particular, its sulphur content are regulated under MARPOL Annex VI. IMO-grounded

The system that delivers treated fuel from the service tank to the engines at the required pressure and temperature.

A tank holding treated fuel ready for immediate use by the engines, kept filled from the settling tanks; required arrangements are set by SOLAS. IMO-grounded

The resistance of a fuel oil to forming sludge or separating when stored or blended, important to avoid filter and system problems.

The system that supplies fuel from the service tank, through booster and heating units, to the engine's injection equipment.

The complete arrangement of tanks, pumps, heaters, filters, and piping for storing, transferring, treating, and supplying fuel oil, with safety arrangements required by SOLAS. IMO-grounded

Design measures, required under MARPOL Annex I, to protect fuel oil tanks from damage and reduce the risk of oil spillage after collision or grounding. IMO-grounded

The system used to move fuel between storage, settling, and service tanks and to receive bunkers.

The cleaning of fuel oil before use, by settling, heating, and centrifugal separation, to remove water and solids.

The arrangement of settling tanks, heaters, and centrifugal separators (purifiers) that conditions fuel oil for use.

Equipment used to prepare and deliver fuel oil to combustion, including pumps, filters, heaters, and associated fittings; defined and regulated for safety under SOLAS. IMO-grounded

The resistance of a fuel to flow, which must be controlled by heating so that the fuel atomises correctly at injection.

The mixing of water into fuel to form an emulsion that, when burned, lowers combustion temperature and reduces nitrogen-oxide emissions.

A trial in which the engine is run full astern from full ahead to measure the ship's stopping ability, a standard manoeuvring test.

The maximum service speed of the ship under normal operating conditions.

A filter through which the entire flow passes so that all the fluid is cleaned before reaching the equipment it serves.

Airborne gases, vapours, or fine particles, often hazardous, given off by substances or processes such as welding or cargo.

The structure carrying the exhaust uptakes of the engines and boilers up and clear of the ship, and housing associated equipment.

The combustion chamber of a boiler, in which fuel is burned to heat the water.

A protective device that melts and breaks an electrical circuit when the current exceeds a safe value.

The melting together of materials, as in the fusion of parent metal and filler in a weld.