Glossary and Conversions
There is no international standard on the unit of measurement for ballast. In this report ballast capacities are given in cubic meters. Appropriate conversion factors are listed below. These assume a freshwater specific gravity of 1.000 and a salt water specific gravity of 1.025. "Gallons" denote U.S. gallons.
1.0 cubic meter
= 1,000 liters (264.17 gallons)
1.0 cubic meter
= 8.386 barrels
1.0 cubic foot
= 0.028 cubic meters
= 31.5 gallons
= 0.119 cubic meters
1 barrel (crude oil)
= 42.0 gallons (no specific gravity given)
1.0 cubic foot (fresh water)
= 28.32 kilograms (62.5 pounds)
1.0 cubic foot (sea water)
= 29.0 kilograms (63.9 pounds)
1.0 long ton (= U.K. ton)
= 1.0160 metric tons (tonnes)
1.0 long ton (fresh water)
= 1.016 cubic meters
1.0 long ton (sea water)
= 0.99 cubic meters
1.0 gallons/minute (gpm)
= 8.02 cubic feet/hour
1,000 metric tons/hour (fresh water)
= 264,170 gallons/hour
1,000 metric tons/hour (fresh water)
= 8,386 barrels/hour
1,000 metric tons/hour (sea water)
= 257,727 gallons/hour
1,000 metric tons/hour (sea water)
= 8,172 barrels/hour
The energy storage molecule of most living systems.
The condition in which oxygen is present.
Toward, at, or near the stern.
A species that is not native to an area (see nonindigenous).
Living in the absence of free oxygen.
The culture of aquatic organisms.
A planktonic carnivorous marine invertebrate of the phylum Chaetognatha.
Behind or from behind the vessel.
See adenosine triphosphate.
Any solid or liquid weight placed in a ship to increase the draft, to change the trim, or to regulate the stability. For the purposes of this study the term ballast includes sediment, which is the debris that comes out of suspension in ballast water and accumulates on horizontal surfaces in ballast tanks.
A watertight enclosure that may be used to carry liquid ballast.
The product of a force acting at a distance from a support or reference point. The vertical bending moment tends to bend the hull in the vertical plane.
Living on or in the bottom of the ocean.
Intersection of the bottom and the side; may be rounded or angular as in a chine-form hull. The lower parts of holds, tanks, or machinery spaces where bilge water may accumulate.
Bilge and ballast system.
A system of pumps and piping generally located in the holds or lower compartments of the ship. This system is used for pumping overboard accumulations of water in holds and compartments and for filling, emptying, and redistributing water ballast.
Stagnant water collected in the lower parts of vessels.
The variety of different types of organisms living in a given area.
The living organisms of a region.
Of, relating to, or located at high latitudes.
An organism that damages the structural integrity of wood or other materials by boring holes into it.
The forward end of a vessel.
Brake horse power (Bhp).
The power produced by the prime mover before entering any reduction gear, if installed.
A vessel designed to carry dry-bulk cargoes, such as ore, coal or grain.
A term applied to the vertical partition surfaces that divide the inside of a vessel into compartments, rooms, and tanks. The various types of bulkheads are distinguished by their location, use, tightness orientation, etc. (e.g., forepeak, transverse, longitudinal, or watertight).
Vertical tracks within the cargo hold of a freight (container) vessel designed to assist loading, unloading, and stacking of containers.
The middle line of the ship. extending from stem to stern. The centerline plane is the reference for transverse measurements.
A phylum of small carnivorous planktonic organisms.
A private, quasi-governmental organization that formulates rules for the construction of ships, monitors their construction, and carries out periodic inspections on ships in service to assure their continued seaworthiness (e.g., American Bureau of Shipping, Lloyd's Register of Shipping, etc.).
Ballast carried in cargo tanks after a crude oil wash, as contrasted to segregated ballast, which is carried in dedicated tanks.
Residue on internal cargo tank structural members after cargo has been discharged.
A vessel designed to carry cargo that is prepacked in large trailer boxes to expedite loading and unloading. The containers typically move to and from the shore terminals on wheeled chassis/straddle carriers.
Small crustacean of the order Copepoda; the dominant planktonic herbivore.
The carrying capacity of a ship at any draft and water density. Includes the weight of cargo, lubricating oil, fuel, fresh water in tanks, stores, passengers and baggage, crew and their effects, and temporary ballast.
To release ballast from a vessel by gravity or pumping.
A horizontal surface in a ship corresponding to a floor in a building.
A tank extending from the bottom or innerbottom up to or higher than the lowest deck. They are often fitted with hatches so that they may carry cargo as well as fuel oil, ballast water, or liquid cargo.
Living close to the bottom of the sea.
Microscopic autotrophic organism of the algae class Bacillariophyceae characterized by being enclosed in a two-valve siliceous capsule.
Microscopic organism of the order Dinoflagellata possessing two locomotory flagellae.
Mechanism that transports organisms from one region to another.
The weight of the ship complete including hull, machinery, outfit, equipment, and liquids in machinery, but no deadweight items.
The weight of the ship when floating at its greatest allowable draft, the sum of the light ship displacement and the deadweight.
The weight of water displaced by the volume of the ship below the waterline measured to the inner surface of the shell plating, without appendages.
The weight of water displaced by the volume of the ship below the waterline measured to the outer surface of the shell plating and including all appendages.
Daily, or every 24 hours.
Deoxyribonucleic acid: the genetic material in (almost) all organisms.
A structural arrangement featuring both inner sides and inner bottom.
The distance the ship extends below the waterline measured vertically to the lowest point of the hull, propellers, or other point. When measured to the lowest point, it is the extreme draft; when measured at the bow, it is the forward draft; when measured at the stern, it is the after draft. The average of the forward and after drafts is the mean draft; the mean draft in the full load or ballast condition is the load or ballast draft.
Commodities, other than in liquid form, that are carried aboard a ship without benefit of packaging. Coal, grain, and various ores are examples.
The ability of a body to remain upright when subjected to various external disturbing influences, such as wind and waves.
A partially enclosed coastal embayment where fresh water and sea water meet and mix.
An organism able to live in an environment of widely varying salinity.
A nation where ships can be registered (see port state).
Technique to quantify the size and volume of organisms and detect natural fluorescence associated with the presence of chlorophyll.
A term indicating location or that portion at or near the bow. Also that part lying between amidships and the bow.
Aligned with the length of the ship; longitudinal.
The lower end of the ship's stem where it curves to meet the keel.
The watertight compartment at the extreme forward end. The forward ballast or trimming tank.
In the direction of the sterm or bow.
An organism that attaches to hard surfaces such as boat bottoms.
To sink and go to the bottom.
Freeboard.The distance from the waterline to the upper surface of the freeboard deck at the side.
The condition of liquid without any constraints on its upper surface, which allows the liquid surface to incline as the ship lists or rolls, making the ship less stable.
Gallons per minute (GPM).
A common measure of volume flow rate in fluid handling systems.
Goods to be transported in a mixture of forms, but usually packaged in some way other than container boxes.
Isopod (crustacean) that eats wood and can destroy wooden structures underwater.
An opening in a deck through which cargo and stores are loaded and unloaded.
A vertical translation motion of a vessel.
The inclination of a ship to one side; also list.
A pair of tanks, port and starboard, used to control the heel of a vessel, particularly to keep the container guides vertical during the loading and unloading of container vessels.
Space below deck for the stowage of cargo; the lowermost cargo compartments.
The structural body of a ship, including shell plating, framing, decks, bulkheads, etc.
The condition in which the vessel is operating with ballast and no cargo.
Inside the ship; toward the centerline.
Release of an organism in a new environment.
Establishment of a reproducing population of an organism in a new region.
An animal without a backbone (vertebral column).
The principal fore and aft component of the strip's framing, located on the centerline of the bottom and connected to the stern and stem frames.
A unit of speed, equaling 1 nautical mile (1,852 m or 6,076.1 ft) per hour; one minute of latitude at the equator.
The side away from the wind.
The transfer of loads to smaller vessels that can enter shallow ports.
Liquefied gas carrier.
A vessel designed to carry gas that has been liquefied by being compressed or cooled. Liquefied natural gas carriers or liquefied petroleum gas carriers are examples.
The inclination of a ship to one side; also heel.
An onboard computer that calculates the drafts, trim, and bending moment on the hull for any condition of loading cargo, stores, and ballast.
The terminus of the pipe or cargo manifold on a vessel to which a hose assembly is connected to the shoreside facility for loading and discharge of cargo.
A shipboard document that defines acceptable ways of loading cargo, stores, and ballast considering drafts, trim, and bending moment.
The deepest draft to which a vessel is allowed to load.
The branch of stability having to do with the tendency of a vessel to trim.
Planktonic organisms that spend only part of their life cycles in the plankton.
The intersection of a vertical line through the center of buoyancy (center of underwater volume) of a heeled vessel with the centerline of the vessel.
Metacentric height, transverse.
The distance from the center of gravity of the vessel to its transverse metacenter (GMt). If this distance is positive at zero heel the vessel is initially stable.
Living in inshore or coastal waters, as opposed to the open ocean.
Not native to an area.
Abbreviation for a vessel designed to move flexibly between the carriage of oil, bulk cargoes, and ore.
Waters with a salinity of 0.5 to 5.0 parts per thousand.
The largest size vessel of a particular type that can transit the Panama Canal.
Living in the water column (contrasted with benthic).
Period of roll, rolling period.
The time it takes a vessel to make a complete roll, that is, from port to starboard and back to port again.
A fore and aft vertical plane rotation motion of a vessel about a transverse axis.
Those organisms free-floating or drifting in water whose movements are determined primarily by water motion.
Fine mesh conical nets dragged in the water to collect plankton.
The plasma is a mass of extremely hot ionized gas formed by passing argon, or some other suitable gas, through a constricted electric arc.
Common marine segmented worms that comprise a large proportion of benthic communities on soft bottoms.
Referring to the left side of the vessel looking forward.
A nation in whose port a vessel enters, as contrasted to a flag state, which is the nation in which the vessel is registered. The port state has the right under international law to enforce a convention (such as MARPOL) to which it adheres on any ship entering its ports and to initiate proceedings in the event of a violation.
Fit for drinking.
Revolving screw-like device used for propelling ships through water or aircraft through air.
Eukaryotic organisms comprised of a single cell.
Range of stability.
The angle of static heel a vessel may undergo without capsizing.
To load water ballast back on a vessel after deballasting.
The name given to massive blooms of dinoflagellates in which the concentration of the organisms is such that the water becomes discolored and toxins are often released in sufficient quantities to affect other marine organisms.
Legally prescribed measure of a vessel's internal volume; originally in units of 100 ft3 (see tonnage, gross and tonnage, net).
Ribonucleic acid, an essential component of genetic function in all organisms.
A transverse vertical plane rotation motion of a vessel about a fore and aft axis.
RO-RO (foll on, roll off).
Abbreviation for a vessel designed to carry vehicles, so arranged that the vehicles can be loaded and unloaded by being driven or rolled on and off on their own or auxiliary wheels, via ramps.
Small planktonic or benthic organisms with anterior cilia on a disk.
The amount of dissolved salts in seawater.
An enclosure, attached to the inside of the shell plating and open to the sea, providing the connection of a piping system to overboard.
A legal term implying that a vessel is capable of safe passage at sea.
Ballast tanks that are used exclusively for carriage of ballast; a vessel designed to carry ballast in segregated tanks.
Parallel forces acting in opposite directions. Also the vertical plane curve of a deck.
Heavy impact resulting from a vessel's bottom near the bow making sudden contact with the sea surface after having risen above the surface due
to relative motion. Similar action can occur due to the rapid immersion of the bow on vessels with large flare.
The condition in which a body will move back to a condition of equilibrium when given a small initial movement away from this condition.
Referring to the right side of the vessel looking forward.
The tendency for a body to remain upright when floating in calm water with no external disturbances.
The bow frame forming the forward most part of the ship.
The after end of the ship.
Storm ballast tank.
A compartment, usually a cargo hold, used only occasionally when a vessel needs to achieve a deep ballast condition for safety in heavy weather.
Deformation resulting from stress on a body.
Force per unit section area producing deformation in a body.
the operation of removing the final portion from a tank not removed by the primary discharge system.
An organism living in symbiosis.
Associated with humans.
A cargo vessel designed to carry liquid cargo in bulk.
Twenty-foot equivalent unit, used to describe the standard unit of containerization.
A unit of weight; a long (gross) ton equals 2,240 lbs; a short (net) ton equals 2,000 lbs; a metric ton (or tonne) equals 2,204.6 lbs.
An approximate measure of a vessel's total volume. A function of the hull volume; originally in units of 100 ft3.
An approximate measure of a vessel's money-earning volume. The gross tonnage with the deduction of the machinery spaces and certain other volumes. Originally in units of 100ft3.
A metric unit of weight equal to 1,000 kgs force or 2,204.6 lbs.
Tonnes per hour.
The branch of stability having to do with the tendency of a vessel to resist heeling and capsizing.
The difference between the drafts; the after draft minus the forward draft. Trim by the stern is positive; trim by the head or the bow is negative.
A tank near the end of the ship carrying fuel or water and used to control the trim of the vessel.
Amount of light-reflecting material in suspension in water.
Turn of the bilge.
A rolled plate section that transitions the flat bottom of a ship to the side. Usually a quadrant of a circle that forms the outer boundaries of the double bottom tank.
An ultra-large crude oil carrier; over about 300,000 DWT (deadweight tonnes).
The condition in which a body will move further away from a condition of equilibrium when given a small initial movement away from this condition.
Diurnal vertical movement of pelagic organisms in the water column toward the surface at night and down to greater depth during the day.
A very large crude oil carrier of between about 150,000 and 300,000 DWT (deadweight tonnes).
A horizontal line on the vessel's side when afloat. Any intersection of a horizontal plane and the molded form of the hull.
The condition in which the vessel is operating with cargo and some ballast.