Ship terms and definations


Access Opening An opening provided to a compartment, which enables access to the compartment and is also used for shifting of equipment into the compartment.      
Accommodation All living spaces for the crew.
Accommodation deck A deck used primarily for the accommodation of the crew
Accommodation Ladder A type of a ladder which is suspended on ships side and is used to embark and disembark personnel from ship to a smaller boat.
Aft Portion of the ship between amidships and stern of ship. 
Aft End             Portion of the ship at or near stern of ship. 
After            Portion of the ship nearer the stern. 
After Peak            It's the Aftermost tank or compartment which can be used for the trimming of the ship.
After Perpendicular            An imaginary vertical perpendicular line drawn with the axis of the Rudder stock. It is used for measuring ships dimension of the length between perpendiculars. It is abbreviated as APP or AP.
American Bureau of Shipping            An American classification society, abbreviated as ABS.
Amidship            Section of ship, which is halfway between bow and stern of ship.
Anchor             A heavy device made of steel which is connected to the end of a anchor chain which is dropped into the sea bed when ship is not alongside a dock. It holds the ship in position during anchorage.
Angle of Rudder             Angle made by the Rudder with the fore and aft center line of the ship.
Anti-Fouling Paint coating           A special paint coating applied to the underwater portions of the ships hull to prevent marine growth.
Assemble            To fit together two or more parts, which would form a section of a larger part. 
Athwart ship          Across the ship, perpendicular to the fore and aft centerline.
Auxiliaries            Equipment other than main engines required by a ship such as winches, pumps, motors, generators, etc
Back gouging            Forming of a bevel or groove on the back of a partially welded joint to obtain a good penetration upon subsequent welding from that side.
Ballast Substance carried by a ship to provide stability of ship. 
Ballast Tank  Water-tight compartment to used to hold ballast. 
Baseline            An imaginary horizontal line, drawn through the molded hull of the vessel often the keel, which maybe used as datum for measuring the vertical distances of ships Hull.
Bay The area between adjacent transverse frames or transverse bulkheads
Beam, Molded           Maximum breadth of the ship's hull measured between the inside surfaces of side shell plate.
Beam,deck            An athwartship Structural member supporting a portion of a deck. 
Beam Bending Machine            A type of bending machine used for straightening or curving deck beams. 
Beam, Knee            A bracket between a deck beam and frame
Beam, Molded            The maximum breadth of the ship's hull measured between the inside surfaces of side shell plate.
Beam, transom            The aftermost transverse side frame, to which are connected cant beams.
Berth            1The place where a ship can be docked; 
           2A bunk or bed used on ships.

1The angle between the different flanges of a frame or other member; 

2 an angle made to the edge of a structural member to facilitate welding. 

Bevel Board  A board used for marking off with num-bers to give the bevel from one frame to another. 
Bilge            The section between the bottom and the side of the hull of the vessel
Bilge Keel             A fore-and-aft vane type plate fitted to the outside of ships hull at the turn of the bilge perpendicular to the hull to prevent excessive rolling of the ship. 
Bilge blocks            Wooden or concrete blocks set under the bilge for supporting the ships hull during construction or dry-docking.
Bilge bracket           A vertical transverse plate welded to the tank top or margin plate and to the frame in way of the bilge area.
Bilge and ballast system            The system used in ships to clear off the water accumulated within the bilges by throwing overboard and is also used to pump water into the ballast tanks. It comprises of equipments such as pumps, educators and pipeline systems.
Bilge Pump            Pump used for pumping out waste water from bilges of ship. 
Bilge plates            The ships shell plates, which form part of the bilge.
Bilge Strake             The hull plates forming the curved section that make the transition from bottom shell to side shell.
Bilge Stringer  A stringer positioned inside and near the bilge of the ship. 
Bilge Water             Water which gets accumulated into the bilges of a ship. 
Bollard             Heavy steel castings fitted to the weather deck of ship for  securing mooring lines or hawsers. 
Bitumastic            Elastic bituminous cement covering usually provided in compartments, decks, etc which is used in place of paint to protect steel from corrosion and increasing its service life.
Block            It's a three dimensional section of the ships Hull being assembled out of many sub parts which would later be fitted to the other blocks of ships Hull in the erection Bay. 
Boat Chock             A wooden or metal piece cut to the shape suitable to fit the under portion of a life boat while resting it on the deck of a vessel. 
Body Plan             A drawing which shows the view of the curves of the frame lines at various sections of the ship. Frames forward of amidships are placed on the right of the center line and aft of amidships on the left of center line. 
Boiler Saddles            Supports for boilers (foundations). 
Bollard, Ventilating            A bollard or bitt having hollow center which is used for passage of air to compartments below. 
Booby Hatch            An access hatch fitted onto the weather deck, which is protected from seawater and weather by a hood. It is also known as companionway.
Boom            A round spar hinged at one end to mast or crane and supported by a wire rope or tackle from aloft to the upper end of the boom. It is generally used for lifting Cargo, stores, etc. by the tackle leading from the upper end of the boom.
Boom Crutch  Support for stowing booms when they are not in use. 
Boot-topping           A band of colour separate from the one used for the bottom and that used for the top sides (above waterline). The line of this paint is only for a short distance above the water and it is designed to improve the appearance of the ship. Sometimes this is formed by carrying up above the water line, the same colour paint as used in the bottom plating.   
Bosom Piece  A short angle used for connecting the ends of two angles. 
Boss           The curved portion of the ship's hull near the stern post that surrounds and supports the propeller shaft. It is also called propeller boss.
Bossing Plate            Steel plate covering the bulged portion of the ship's hull where the propeller shaft passes outboard.
Bottom            Portion of the hull below the bilge of ship. 
Bow           Forward end of a ship. 
Bower Anchor An anchor carried at the bow of the ship
Bracket            A small plate type structural member used to connect two or more structural parts, such as deck beam to frame, or bulkhead stiffener to the deck or tank top.
Bracket toe The narrow end of a tapered bracket
Breakwater            A small plate type of structure built on the forward end of the weather deck of ship to protect the crew from waves which might wash over the bow. 
Breast Hook            A triangular plate bracket forming part of the hull structure, fitted inside the hull near the bow to give local strength to the shell plating. 
Bridge            The conning station or command post of a ship from which the ship is steered, navigated, etc. 
Buckled Plate            A plate which is bent out of its shape. 
Building Slip           Place where the ship is constructed, before launching. 
Bulbous bow            A bow with a round bulging shape at the forward bottom portion of a ship to improve flow and resistance characteristics.
Bulb profile A stiffener utilising an increase in steel mass on the outer end of the web instead of a separate flange
Bulk carrier            Ships, which are designed to carry bulk cargo such as coal, ore, grain, etc.
Bulkhead            A vertical partition corresponding to the wall of a building. It extends either athwartships or fore-and-aft. It sub divides the interior of a ship into compartments or rooms. Bulkheads, which contribute to the strength of a vessel, are called strength bulkheads. Those, which contribute for watertight subdivision, are called watertight bulkheads. Gastight bulkheads serve to prevent the passage of gas or fumes.
Bulkhead, Collision            The foremost bulkhead, which would serve as the front of the ship if the bow was destroyed by collision. 
Bulkhead, Corrugated            A system of using corrugated metal for light partition bulkheads and avoiding use of the stiffener angles for the Bulkhead. 
Bulkhead deck The uppermost continuous deck to which transverse watertight bulkheads and shell are carried
Bulkhead stool The lower or upper base of a corrugated bulkhead
Bulkhead Stiffeners             Angle or channel bars fitted onto the plates of a bulkhead to stiffen it. 
Bulkhead structure The transverse or longitudinal bulkhead plating with stiffeners and girders
Bulkhead, Wash            A partial bulkhead in an oil or water tank to prevent the splashing of the oil or water when the tank is not full. (Same as Swash Plate.) 
Bulwark            Shell plating extending above the top deck of a ship. 
Bulwark Stays             An inclined brace from deck to inboard side of the bulwark plating to adequately stiffen the bulwarks. 
Bunker A compartment for the storage of fuel oil used by the ship's machinery
Buoyancy             Ability to float, or the difference between the weight of the ship and the upward force of the water that it may displace. 
Bushing            A metal or lignum vitae collar used around a revolving shaft to take up the wear. 
Butterfly Nut            A nut having two large "wings" which facilitates tightening the nut by hand. 
Buttock             The convexity of a ships aft, under the stern. 
Cable-Chain            Chain used for attaching the anchor. 
Cable Stopper(or Chain Stopper)            A device used to hold the anchor chain when anchor is in use. 
Camber  The athwartship curvature of a deck.  
Cant Frame A frame not square to the keel line (small frame supporting overhang of stern). 
Capstan  A device, with vertical axis, used for heaving in lines. 
Cargo  The freight being carried by a ship. 
Cargo area The part of the ship that contains cargo tanks and cargo/slop tanks and adjacent areas including ballast tanks, fuel tanks, cofferdams, void spaces and also including deck areas throughout the entire length and breadth of the part of the ship over the mentioned spaces. It includes the collision bulkhead and the transverse bulkhead at the aft end of the cargo block.
Cargo Hatch An opening provided in a deck to permit the loading and unloading of cargo in the cargo hold. 
Cargo tank bulkhead A boundary bulkhead separating cargo tanks
Carlings A stiffening member used to supplement the regular stiffening arrangement,
Center Line  The imaginary center line passing between fore and aft sides dividing the ship into two symmetrical halves. 
Centreline girder A longitudinal member located on the centreline of the ship
Center Punch  A small hand tool, used to mark the center of a hole. 
Chain Locker  A Compartment provided in the forward lower portion of the ship in which anchor chain is stowed. 
Chain Pipe Pipe provided for passage of anchor chain from ships deck to the chain locker. 
Chain stopper A device for securing the chain cable when riding at anchor as well as securing the anchor in the housed position in the hawse pipe, thereby relieving the strain on the windlass
Chock             An opening provided on the ship through which ropes or hawsers may be led .
Chock, boat            A cradle or support usually of wood, provided for stowing lifeboat/workboat onboard.
Cleat            A deck fitting fitted onto the deck, having two fore- and-aft arms or projections around which a rope or line may be secured. 
Clip             A short length of angle used to align structural sections. 
Coaming             A vertical plate extending above the deck and fitted around an opening and is used to stiffen the edges of the opening. It also prevents entry of water.
Cofferdam             A narrow void space between two bulkheads or floors to isolate the two compartments.
Collar plate A patch used to, partly or completely, close a hole cut for a longitudinal stiffener passing through a transverse web
Collision Bulkhead            First water-tight bulkhead from bow of ship. 
Companionway A weathertight entrance leading from a ship's deck to spaces below
Compartment            A subdivision of space or room in a ship. 
Compensation            The fitment of doubler plates around hatches, etc., to improve the local strength around the opening. 
Confined space A space identified by one of the following characteristics: limited openings for entry and exit, unfavourable natural ventilation or not designed for continuous worker occupancy
Corrugated bulkhead A bulkhead comprised of plating arranged in a corrugated fashion
Cowl  Hood-shaped top of a ventilator pipe. 
Cradle            A form of support on which the ships is rested during launching.
Crow's Nest  A platform provided at the mast head for lookout or signal man. 
Cross ties Large transverse structural members joining longitudinal bulkheads and used to support them against hydrostatic and hydrodynamic loads
Cruiser Stem A rounded, canoe shaped counter of the ship. 
Cut Water  Portion of stem at water line. 
Davit             A device used to handle lifeboats, anchors, stores, etc.
Davit, Anchor             A davit used for "catting" the anchor. 
Dead Rise             The rise of the bottom of a ship from the keel to the bilge. 
Deadweight            The total weight of cargo, fuel, water, stores, passengers and crew, and their effects, that a ship can carry. 
Deck            The portion of a ship which is similar to the floors in a building. 
Deck (Boat)           The deck that is used to stow the life boats on the ship.
Deck (Bridge)            Portion of the deck extending from side to side of the ship, about amidships. 
Deck (Forecastle)            Portion of the deck at bow of ship, raised above upper deck. 
Deck (Girder)            Strength member extending either fore- and-aft or athwartships which provides the adequate support to the deck. 
Deck (Lower or first)           First full deck above tank top or bottom. 
Deck (Main or second)             Second full deck above tank top or bottom. Principal deck of the main part of the hull. 
Deck (Poop)            Portion of deck at stern of ship, raised above upper deck. 
Deck (Promenade)            A deck set aside which is exclusively for the use of first- class passengers on passenger ships. 
Deck (Upper or third)            Third full deck above tank top or bottom. 
Deck (Orlop)            Partial or balcony deck between tank top and lower deck. 
Deck Height           The vertical height from the top of a deck to the top of the next deck above. 
Deck Load             Cargo stowed on weather deck. 
Deck Light             A small thick glass in a frame which is fitted on weather decks to let light pass into compartments below.
Deck Plan             A drawing showing the layout of a deck, 'either for plating or arrangement. 
Deck Stringer             Strake of plating that runs along the outer edge of a deck. 
Decking             Wood, or any other material used to cover a deck. 
Depth              The distance between the top of the Upper Deck beam, at the side, to the base, line of the vessel, measured half way between the ship's forward and after perpendiculars.
Derrick            A device used for hoisting heavy weights, cargo, etc. 
Diamond Plates             Diamond-shaped plates used to connect the web frames to the side stringers and act as brackets thus stiffening the framework. 
Displacement              See Tonnage.
Docking brackets            Short transverse flanged plates in the inner bottom structure that run from the central vertical keel to the first longitudinals on both sides of the keel. They usually alternate with the floors.
Dog            A small metal device used for securing doors, hatch covers, manholes, etc., in a closed position.
Double bottom            Compartment at the bottom of a ship between inner bottom and the shell plating, mostly used for ballast water, fresh water or fuel oil. 
Doubling plate            A plate fitted outside or inside of another to give extra strength or stiffness.
Draft  The vertical distance of the lowest part of the ship below the surface of the water when a vessel is afloat. 
Draft marks            The numbers painted on each side of the ship located at bow and stern and sometimes amidships. It indicates the distance from the lower edge of the number to bottom of the keel or other fixed reference point. The numbers are 6 inches high and spaced six inches apart. Draft marks may also be provided in meters.
Draft, Mean             An average of the draft at the bow and stern. 
Dry Dock             A floating (or stationary) box-shaped structure into which vessels may be towed and the water pumped out from around the vessel for purposes of underwater surveys or carrying out repairs of the ship. 
Eductor room            A pump room to transfer liquid cargo
Engine room            The place on board a ship, where main propulsion and auxiliary machinery of a ship are located.
Ensign staff            A flagstaff at the stern.
Erection            The connection of all the subassemblies, blocks and outfit units of a ship, either on slip ways or any other building position.
Escape trunk            A vertical trunk equipped with a ladder to permit personnel to escape when trapped. It is usually located in the aft end of a vessel between the shaft tunnel and upper decks.
Eye Bolt  A bolt formed with an eye or ring at one end. 
Fabricate            To process materials in the shops, to create parts needed for both hull and outfit assemblies. Fabrication usually consists of punching, cutting, shearing, shaping, drilling, countersinking, beveling and welding.
Fair            The process of smoothening the abruptness or unevenness from parts of assemblies.
Fairlead             A small deck fitting through which a rope, or chain can be led so as to change its direction without excessive friction. 
Fairwater            The term used for the plating fitted around the ends of shaft tubes and strut barrels, and shaped to streamline the parts, thus eliminating abrupt changes in the water flow.
Fantail            The overhanging stern section, which extends well after the after perpendicular and may also be called counter stern.
Fashion plate            A bulwark after the bow and above the forecastle deck.
Fender             A device made of wood or rubber fitted or hung over around the ships side to prevent the shell plating from rubbing or chafing around other ships or piers.
Fidley            the top of the engine and boiler room; Casings on the weather deck; a partially raised deck over the engine and boiler casings, usually around the smokestack.
Fire Main             The pipe used only to supply water to the fire hydrants located at various locations from the fire pump. 
Fine Lines  When ship is sharp pointed at the ends. 
Flange            The part of a plate or shape bent at right angles to the main part; to bend over to form an angle.
Flare  Curvature of the forward frames outward. 
Flat            A small partial deck or machinery level, usually built flat.
Floor            The lower portion of a transverse frame, usually a vertical plate extending from center line to bilge, and from inner to outer bottom. 
Fore-and-aft             Along the length of the ship. 
Forecastle            The forward, upper portion of the hull.
Fore Peak             A compartment or tank at the extreme forward end of the ship, used for trimming of ship. 
Forefoot            Lower end of a ship's stem, which curves to meet the keel.
Forward             Near or toward the bow. 
Foundation            A structural support for equipment and machinery in a ship. The structural support for the boilers, main engines or turbines, and reduction gears are called the main foundations. 
Frame            The term used for the transverse members, the rib like part of the skeleton of a ship. The frames act as stiffeners holding the outside plating in shape and maintaining the transverse form of the ship.
Frame Spacing            The fore-and-aft distance between adjacent frames. 
Framing             The support and stiffening of the shell plating, deck plating. Usually it consists of ordinary transverse frames (or '' ribs ") beams, floors, and the longitudinal framing, as keel, keelsons, longitudinal and stringers. 
Freeboard             The vertical distance from the upper watertight deck or top of bulwarks to waterline, when ship is fully loaded. 
Freeing Port             Holes through lower portion of bulwarks of ship used to drain water overboard. 
Full Lines             When ship is blunt pointed at the ends. 
Funnel            A chimney through which combustion products are lead from propulsion and auxiliary machinery to the weather.
Galley             Cook room or kitchen of a ship. 
Galley Dresser             A cook's work table. 
Galvanizing             Coating metal parts with zinc to protect from corrosion.
Gangway            A passageway, a ladder or other means used to board a ship. 
Garboard Strake             The strake of bottom shell plating adjacent to the keel plate.
Girder            Strengthening member to support horizontal or vertical loads. It is larger than a longitudinal or stiffener.
Girth            Any expanded length, such as the length of a frame from gunwale to gunwale.
Grommet            A soft ring under the nut or bolt to maintain watertightness.
Gross Tonnage            See Tonnage. 
Gudgeons             Bosses on stern post drilled for pins, on which the rudder can swing. 
Gunwale  The side of a ship above the weather decks. 
Gunwale bar           The angle connecting the deck plating to the shell plating or to the inside of the frame. The stringer bar on the strength deck is usually called gunwale bar.
Gusset plate            A bracket plate lying in the horizontal or nearly horizontal plane
Hatch            Opening in deck, for passage of people or cargo. 
Halyard            Light lines used in raising signals, flags, etc.
Hatch Beam             A portable beam across the hatch to support hatch covers.
Hatch, Cargo            Large openings in a deck to permit loading of cargo. 
Hatch Coamings            The vertical plates around the edge of a hatch-way. 
Hatch, Fidley            Hatch over Boiler Room. 
Hatchway            The vertical opening under a hatch. 
Hawse Pipe            Casting that extends through deck and the side of ship for passage of anchor chain. 
Hawser            A large rope. 
Hawser Hole            Hole through bulwark for passage of a rope. 
Heeling            The degree of inclination of the ship from the perpendicular. 
Hogging            Straining of the ship that tends to make the bow and stern lower than the middle portion. 
Hold            That portion of a vessel used for stowage of cargo. 
Holding-down Bolts  The bolts which hold any machine to its seating. 
Horning            A method of checking the accuracy of a layout of a square or rectangular plate by matching diagonal measurements.
Hull            The body of a ship, including shell plating and frames. 
I-Beam            structural shapes with a cross section resembling letter I.
Ice-strengthening            Special strengthening for ships operating in ice as specified by a classification society
Inner bottom            The plating forming the top of the double bottom (tank top).
Intercostal           Made of separate parts running between floors, frames or beams; the opposite of continuous.
In Way of             A nautical term meaning "near-by" or ''parallel to".
Inboard            Inside the ship, toward the center line. 
Insulation            Material used to prevent heat transfer at various locations. 
Jackstaff             Flagstaff at the bow of the ship. 
Jig            A device used to hold a piece of work.
Joinery            Work, which involves lightweight materials (metallic and non-metallic), such as bulkheads and ceilings in accommodation spaces.
Keel              The fore-and-aft member of the hull structure, usually in the form of horizontal flat plates end to end, located at the center line from stem to stern along the bottom of a ship. 
Keel Blocks             Heavy blocks made of wood or concrete, on which ship rests during construction. 
Keelson, Side             Fore-and-aft member located on each side of center keelson. 
Knee  A bracket connecting a beam to the frame. 
King Post            A vertical post used to support cargo booms. 
Knuckle             A sharp bend in a plate or bar. 
Landing Boards   Boards on deck beside hatches, for landing cargo when loading.
Landing Edge The edge of a plate which is nearest the landing. 
Lap or Landing A joint, in which one part of a plate overlaps another.
Launching.  The operation of placing the hull in the water by having it slide down the launching ways. 
Launching Grease  Melted Russian tallow of the best quality smeared over with soft soap and train oil to increase lubrication is one of the many combinations on the market. 
Laying off   Marking plates, shapes, etc., for shearing and punching from template.
Lay Up To strike the plate near a rivet hole after the hot rivet has been insert


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