Shipyard Terms and Definitions
Ship Terms and Definitions
Abaft —-Aft of; farther aft than.
Access Holes—- Holes cut in ship’s structure to permit entering or leaving various compartments.
Accommodation Ladder—- A portable set of steps on a ship’s side for the accommodation of people boarding from small boats or from a pier.
Aft —-Toward, at, or near stern.
After—– Nearer stern.
Aftermost—- Nearest the stern.
After Body—- Hull form aft of the midship section.
After Peak—- The compartment in the narrow part of the stern, aft of the last water-tight bulkhead.
After Peak Bulkhead —- Watertight bulkhead farthest aft.
After Perpendicular —-A vertical straight line at, or near the after edge of rudder post.
Air Hammer—- Hammer driven by compressed air for riveting, or chipping. Sometimes called an air gun or “gun.”
Air Port —-A circular opening or window through the ship’s, or deck house, for light or ventilation.
Amidships —-At or near the midship section of the ship.
Anchor —- A heavy hook-shaped device for holding a ship at rest in water. The anchor grips the ocean bottom and is fastened to the ship by a chain. There are a number of different types of anchors. Some of the different anchors are: Work boat anchors, Stockless, Hall, Mushroom, Eells, Kedge, Navy pattern, Union, and Speck.
Anchor Joining Link —-A chain member with a removeable part used to connect the anchor to the swivel on the chain assembly.
Angle Clip—- A short piece of angle bar.
Angle Collar —-A ring made of angle bar.
Anneal —-To soften metal by heating and allowing it to cool slowly.
Anode —-Zink or aluminum or some such alloy that is fixed to the hull of a vessel. They are ‘eaten’ up by electrical currents moving from the vessel to the water. The anode is sacrificed to protect the metal hull of the vessel – without the anode, the hull plating would be dissolved by electrolysis.
Aperture —-A recess in which the propeller is located.
Assemble —-To fit together small parts, in making a large section,or part .
Athwartship —-Across the ship at right angles to the centerline.
Auxiliaries —-Machinery supplementary to main propulsive units.
Awning Deck —-Shade deck above another deck.
Babbet —-A relatively soft metal alloy used for bearings.
Ballast —-Any weight or weights (usually sea water, but could be concrete, scrap steel, etc.) used to keep the ship from becoming “top heavy” or to change her trim. Some of the largest cannons in the navy were on hospital ships – they were in the bilge for ballast.
Ballast Tank —-Watertight compartment to hold ballast.
Barge —-A water tight vessel that floats in water. Cargo barges in the USA do not have propulsion. Picture of 2 loaded inland rivers tank barges, carrying liquid cargo. Some have tanks for carrying oils and chemicals, others have hoppers for dry cargoes like grain or just a flat deck for specialized cargo. In the USA oil and chemical tank barges must meet US Coast Guard rules and regulations. The plans must be approved prior to construction and all repairs must be approved by the USCG. They must be drydocked on a schedule for routine underwater inspection.
Barnacle —-Small marine growth which attaches itself to a vessel’s hull in large numbers, often greatly retarding her speed.
Battens —-Long strips of wood used in the mold loft for fairing lines; also, wooden protective strips in cargo holds; see hatch battens.
Beam —-An athwartship member supporting a portion of a deck. Also,the width of the ship.
Beam Knee —-(See Bracket)
Below —-Below a deck or decks (corresponding to “downstairs”).
Bend —To fasten; as, to bend on a rope
Bending Rolls —-Large machine used to give curvature to plates. Also see ‘press brake’.
Bending Slab—- Heavy cast iron perforated slabs arranged to form a large floor on which frames, etc., are bent.
Berth —-A place for a ship; a place to sleep; a bunk; also, a specified small section of the hull structure.
Between Decks —-The space between any two decks.
Bevel —-The angle between the flanges of a frame or other member.(When greater than a right angle, open bevel; when less, closed.) Also,to chamfer.
Bilge —-Curved section between the bottom and the side of a ship;the recess into which all water drains.
Bilge Blocks —-Supporting blocks used under bilge for support during construction or dry docking.
Bilge —-A fore and aft member fitted to the outside of the shell plating along the bilge, to prevent excessive rolling of the ship.
Bilge Pump —-Pump for removing bilge water.
Bilge Strake —-Course of plates at the bilge.
Bilge Water —-Water in ship due to leaks, sweat, etc.
Bilge Well —- A sump to which bilge water drains.
Binnacle —-A case, box, or stand containing a ship’s compass, adjusting magnets, and a lamp for use at night.
Bitt —-A vertical post used in making fast lines; a bollard.
Bitumastic —-An elastic cement used in place of paint to protect steel.
Boat Deck —-A deck on which lifeboats are kept.
Body Plan —-A drawing which shows frame lines in elevation.
Boiler —-Container in which water is heated to form steam.
Boiler Chocks —-Stay braces which prevent fore and aft movement of boilers.
Boiler Foundation —-A support for a boiler.
Bollard —-A single tie post (see bitt).
Booby Hatch —-A watertight covering over a deck opening, which is used for a stairway or ladder.
Boom —-A long, round, heavy spar, pivoted at one end, usually used for handling cargo, etc.
Boom Rest —-A support for a boom when the boom is not in use.
Boom Step —-A socket for end of boom.
Bosom Piece —-A short piece of angle riveted over a butt joint of two angles, a butt strap for angle bars; a splice piece.
Boss —-The curved swelling portion of the ship’s hull around the propeller shaft.
Boss Frame —-A hull frame which is bent for clearing propeller shaft tube boss
Boss Plate —-A shell plate covering the curved portion of hull where the propeller shaft passes outboard.
Bow —-The forward end of a vessel. (Usually the pointed end.)
Bowsprit –A spar projecting forward from the bow of a vessel used to attach sails and stays.
Bracket —-A triangular plate used to connect rigidly two or more parts, such as a deck beam to a frame, a frame to a margin plate, etc.
Braze —-To heat and join by means of hard solder (spelter). This may be brass, bronze, or other alloys.
Breakwater —-A braced guard plate which prevents solid water from sweeping the decks.
Breast Cap —-Small plate on top of bulwark, at stem of vessel to stiffen bulwark.
Breast Hook —-A triangular-shaped plate extending horizontally across the bow behind the stem, stiffening the stringers and stem.
Bridge, Navigating —-A deck from which the ship is navigated.
Bridge Deck —-A deck of the superstructure amidships.
Brow —-A watershed over an airport; a small inclined runway to allow passage of trucks over hatch coaming, or through bulkhead door, etc.; sometimes portable.
Buck frame —-In a double skin tank barge, these frames act as spacers in the void tanks. A 4’6″ wide void might have 2 vertical 8″ channel iron with 3″ x 3″ x 5/16″ angle iron between. Also called a transverse truss.
Building Slip —-A place where the ship is built; a shipway.
Bulb Angle —-An angle shape, which is reinforced at one toe.
Bulb Plate —-A narrow plate reinforced on one edge.
Bulb Tee —-A Tee bar with toe of web reinforced.
Bulkhead —-A vertical partition corresponding to the wall of a room, extending either athwartships or fore and aft. A steel partition in a ship.
Bulkhead Sluice —-A small opening in a watertight bulkhead which can be opened or closed from the deck above.
Bulwark —-The ship’s side above the weather deck.
Bull Riveting —-Driving rivets by squeezing them with a high powered air or hydraulic machine.
Bunker —-A compartment used for the stowage of coal or other fuel.
Buoyancy —-Ability to float; lifting power when immersed.
Butt —-The joint formed when two parts are placed edge to edge.
Buttock —-A distance from centerline; an intersection of moulded surface with a vertical longitudinal plane.
Butt Strap —-A small plate used to connect the two parts of a butt joint by overlapping each; a splice piece.
Butterworth (TM) Gun —-Butterworth is the name of a company that manufactures automatic tank wash machines. The machines can be hose mounted or permanent. The water flowing through the machine causes the wash nozzles to turn. Gears inside the machine make the spray pattern ecentric so all the walls and floor is washed without moving the hose. (At least all that can be sprayed from the one piont.) The cycle time is adjustable although not necessarily in the field.
Butterworth Hatch —- An opening on the deck of a vessel opened when cleaning or ventilating the tanks. May be round or square, secured by bolts or dogs.
Button —-A cast or fabricated deck item, usually round, that is used to thread cables between vessels when they are made-up.
Caboose —-A kitchen on deck.
Camber —-The athwartship rise or crown of a deck.
Cant Frame —-A frame which is not square to the keel line.
Capstan —-A revolving drum, with vertical axis, used for heaving in lines.
Cargo —-The freight carried by a ship.
Cargo Battens —-Strips of wood used to keep cargo away from the steel hull.
Cargo Boom —-A heavy boom used in handling cargo.
Cargo Hatch —-A large opening in a deck which permits the loading of cargo into holds.
Cargo Port —-An opening in a ship’s side used in loading and unloading cargo.
Casing Bulkheads —-Walls enclosing portion of vessel, as the boiler room casing. Also a covering for parts of machinery.
Cat’s paw —-A light puff of wind.
Caulk —-To make a joint watertight. The old saying ‘the devil to pay and a half bucket of pitch’ referred to a very big joint to be caulked (pay) with the pitch and there may not be enough pitch.
Caulker —-One who caulks.
Ceiling Wood —-Sheathing on the tank top, sides of ship, and bulkheads; used to protect cargo.
Center Keelson —-(See vertical keel).
Center Line —-The middle line of the ship, extending from stem to stern .
Chafing Plate —-A bent plate used in minimizing chafing of ropes,as at hatches.
Chain Locker —-A compartment in the forward portion of ship in which anchor chain is stowed.
Chain Pipe —-A pipe for passage of anchor chain from deck to chain locker.
Chain Riveting —-Two or more rows of rivets spaces so that the rivets in one row are opposite those in an adjacent row.
Chain Stopper —-A device which prevents anchor chain from running out. It is moved into position after the anchor has been dropped.
Chamfer —-To cut off the sharp edge of a 90o corner. To trim to an acute angle.
Channel Iron —-A steel shape commonly used in vessel construction.
Chart Room —-A small room adjacent to the Pilot House in which charts and navigating instruments are located.
Chock —-A heavy fitting through which ropes or hawsers may be led.A saddle or seat of wood or metal.
Chock-Boat —-A cradle or support for a lifeboat.
Chock-Roller —-A chock with a sheave to prevent chafing of ropes.
Cleat —-A fitting having two arms or horns around which ropes may be made fast. Also called a kevel. A clip on the frames of a ship used to hold cargo battens in place.
Clinching Pan —-A flat plate for clinching nails. (Used in the mold loft.)
Coaming —-The vertical boundary of a hatch or skylight.
Cofferdam —-A narrow vacant space between two bulkheads. A double watertight bulkhead.
Collar —-A flanged band or ring. A welded plate used to close a frame or beam penetration through plating.
Collision Bulkhead —-The watertight bulkhead nearest the bow of a ship; forepeak bulkhead.
Companionway —-A covered stairway leading downward from an open deck. A series of steps leading from the deck to a cabin or saloon below; also, the space occupied by these steps.
Compartment —-A subdivision of space or room in a ship.
Corrugated —-Having a series of wrinkles or grooves arranged so as to produce stiffness.
Corrugated Bulkheads —-Bulkheads with corrugated plating, eliminating the need for many welded stiffeners.
Counter —-Overhang of the stern of a ship.
Countersink —-To taper a hole for a flush rivet or bolt.
Cowl —-The hood-shaped top of a ventilator pipe.
Cradle —-A form on which bows, etc., are assembled. The support in which a ship rests during launching; a launching cradle.
Cross header —-A pipeline that crosses over a tank providing a transit for cargo without tying into the vessel.
Cyclodial propulsion system —-A system of vertical blades that have taken the place of propellers for propulsion in some applications. Made by Voith Hydro GmbH & Co.. Generically referred to as a “tractor system”.
Cutless Bearing —-A rubber bearing used to steady the propeller shaft in the water. It usually has longitudinal groves to catch water which then acts as a lubricant. The rubber is fused to a brass tube. The brass tube is pressed into a steel tube or cylinder and the steel is welded to the vessel hull. The fits and alignment have to be exact for these items.
Davit —-A crane arm used in handling small boats, lifeboats, stores, gear, etc.
Dead Eye —A flat disc (originally of wood) spliced to a shroud. Lanyards are passed through holes in the disc to connect them to the shrouds
Dead Flat —-A portion of a ship’s side or bottom where the plating has no curvature; also, the midship portion of constant cross section.(The parallel middle body.)
Dead Man —-A buried timber (etc.) that has an attached pipe or cable going to the surface for the purpose of securing a vessel at a dock or along a riverbank.
Dead Rise —-The rise or upward slant of the bottom of a ship from the keel to the bilge.
Dead weight—-The total weight of cargo, fuel, water, stores, passengers and crew, and their effects, which a ship can carry.
Deck —-A part of a ship corresponding to the floor of a building.
Deck-House —-A shelter built on deck.
Declivity —-Inclination of shipways to provide for launching.
Deep Tank —-A deep compartment usually extending from tank top to lower deck.
Derrick —-A device for hoisting heavy weights, cargo, etc.
Die —-A tool for forming a rivet head (applied to rivet dies).
Displacement —-The total weight of the ship when afloat, including everything on board, (equals weight of water displaced.) Usually expressed in long tons.
Dog —-A small bent metal fitting used in closing doors, hatch covers, manhole covers, etc.; a bent bar of round iron used in holding shapes on bending slab; any small flat lug temporarily welded to structure as backing for a wedge.
Dolly Bar —-A heavy bar to hold against a rivet, to give backing when riveting.
Double Bottom —-Compartments at bottom of ship between inner and outer bottoms, used for ballast tanks, water, fuel,oil, etc.
Doubling Plate —-A plate fitted outside or inside of another to give extra strength or stiffness.
Drag —-The amount the stern end of the keel is below the bow end when the ship is afloat, but not on an even keel.
Draft —-The vertical distance of the lowest point of the ship below the surface of the water, when afloat.
Draft marks are the painted numbers on the side of a vessel. The numerals are 6″ tall and are placed on the side shell so the bottom of the numeral is at the indicated depth. For instance, if a 1′ numeral is placed, then the bottom of the numeral is the 1′ mark and the top of the numeral is at the 1′ 6″ mark.
Drift Pin —-A small tapered tool used in aligning holes in adjacent members.
Drop Strake —-A strake discontinued near the bow or stern.
Drydock —-A watertight vessel fitted with pumps and valves usually built in a u-shape. The valves are opened, the vessel sinks, the vessel to be docked is pulled over the drydock deck, the valves are closed and the pumps are started, as the drydock becomes more buoyant, drydocking the vessel to be repaired.
Erecting —-The process of hoisting into place and bolting the various parts of a ship’s hull.
Even Keel —-A ship is said to be on an even keel when the keel is level or parallel to the surface of the water.
Expansion Trunk —-Raised portion of tank used on some oil tankers to allow for the expansion of oil when temperature changes.
Eye Bolt —-Bolt whose head is in the form of a ring or eye.
Fabricate —-To make assemblies from ‘raw’ material.
Face Plate —-A narrow stiffening plate welded alone the edge of any web frame or stiffener.
Fairing or Fairing Up —-Correcting or fairing up a ship’s lines or structural members; assembling the parts of ship so that they will be fair,that is, without kinks, bumps, or waves.
Fairlead —-A fitting through or over which a rope, line, etc., maybe led so as to change its direction without excessive friction.
Fairwater —-Plate or casting used to preserve streamline flow of water past the hull structure or propeller hub.
Fathom —-Six feet. 120 fathoms = 1 cable. 6,085 feet = 1 nautical mile
Fathometer —-A device to measure the depth of water, by timing the travel of a sound wave from the ship to the ocean bottom and return.
Faying Surface —-The contact surface between two adjoining parts.
Fender —-A portable device to protect a ship when bumping a pier;sometimes made of wood, rope, etc.; permanently installed extension which protects the hull of a ship in docking.
Fidley —-Casing top over boiler room.
Fidley Hutch —-A hatch over boiler room.
Figurehead — The bust, often of a woman, on the bow of a vessel, just under the bowsprit.
Flagstaff —-Flagpole at stern of ship; ensign staff.
Flange —-A part of a plate or shape at, or nearly at, right angles to main port; to bend over to form an angle.
Flare —-The sudden widening of the shell at top near the bow.
Flat —-A small partial deck (built level) without curvature.
Floor —-The lower portion of a transverse frame, usually a vertical plate extending from center line to bilge, and from inner to outer bottom.
Flotsam —-Floating objects or debris in the water – wreckage that floats after a vessel sinks.
Fore and Aft —-In line with the length of the ship, longitudinally.
Fore and Aft Gangway —-A walkway between deck houses at or near centerline of ship.
Forebody —-A hull form forward of the midship section.
Forecastle —-The forward upper portion of the hull, sometimes used for the crew’s quarters.
Forefoot —-The part of the keel which curves and rises to meet the Stem.
Forepeak —-The large compartment or tank, at the bow in the lower part of the ship.
Forepeak Bulkhead —-Collision bulkhead; bulkhead nearest bow.
Forging —-Steel worked to special shape by hammering while red hot.
Forward—-Near, at, or toward, the bow of the ship.
Forward Perpendicular —-A vertical line through the intersection of the stem with the load water line.
Foundations —-Supports for boilers, engines, and auxiliary machinery.
Foundations, Auxiliary —-Supports for small machinery, such as winches, condensers, heaters, etc.
Frames —-Ribs forming the skeleton of a ship.
Frames —-Continuous Frames combining side frames and floors.
Frame, Side —-Frame inside a ship, above and connecting to margin plate or floor plates.
Frame Spacing —-The fore and aft distance between adjacent frames.
Frame, Web —-A heavy side or continuous frame, made with web plate for extra stiffness.
Freeboard —-The vertical distance from the upper watertight deck to waterline, when the ship is fully loaded.
Freeboard Mark —-(See Plimsoll mark.)
Freeing Port —-Hole through bulwark which provides ready drainage of water from deck.
Funnel —-A smokestack of a vessel.
Furnace —-A heater or large forge for heating plates or shapes for bending; to bend by heating in furnace.
Gaf Spar —-The honored place on a ship flag pole for the stars and stripes. All other flags fly at a lower place.
Galley —-A cook room or kitchen.
Galley Dresser —-A cook’s work table.
Galvanizing —-Coating metal parts with zinc for protection from rust.
Gangway —-A passageway, a ladder, or other means of boarding a ship.
Garboard Strake —-The course of plates next to the keel of a ship.
Gasket —-Packing of canvas composition, or other material, used in making a joint that does not leak. Composition gaskets may have used asbestos. Since the awareness of asbestos as a health problem, asbestos is not often used. Gaskets may be rubber, composition, spiral wound with metal and composition, etc. O-rings are a type of gasket.
Girder —-Fore and aft stiffening member for deck or bottom shell.
Girth —-Any expanded length.
Grab Rods —-Bent rods welded to bulkheads or ship’s side to form a ladder.
Grating —-Light platform or walkway built up of metal bars, used for access to machinery.
Graving Dock —-A arrangement for getting vessels out of the water so that bottom work can be done. Usually a slip is dug in the shore, a vessel is floated in, a wall is placed across the open end of the slip and the water is pumped out of the ‘tank’. Often used for very heavy objects.
Grommet —-A soft ring used under a nut or bolt head to maintain water tightness.
Ground Ways —-Timbers secured to the ground, under the hull on each side of the keel, on which a ship is launched.
Gudgeons —-Bosses on stern post drilled for pins (Pintles) on which rudder swings.
Gunwale —-The junction of deck and shell at top of sheer strake. Pronounced ‘gunnel’
Gunwale Bar —-Angle iron which connects stringer plate and shell plates. (Riveted work)
Gyro-Compass —-A mechanical compass operated by means of a gyroscope. This compass indicated true north rather than magnetic north.
Gyro-Repeater —-An apparatus to show the reading of the gyro compass at a distance from the main gyroscope equipment.
Halliard —-A line for raising or lowering a sail or a flag.
Hatch —-An opening in a deck for passage of cargo, etc.
Hatch Battens —-Flat bars which are wedged against hatch coamings to secure tarpaulins.
Hatch Beam —-A portable beam used to support wooden hatch covers.
Hawse Pipe —-Casting, or castings, through deck and side of ship at bow for passage of anchor chain.
Hawser —-A large rope used in towing or mooring.
Headlog —-The bow plate on a vessel that is made of thick steel plate.
Heeling —-The inclination of a vessel to one side.
Hogging —-Straining of the ship which tends to make the bow and stern lower than the middle portion. This is the opposite of sagging.
Hog Wire —-On early vessels and river boats the problem of hogging was solved to some extent by putting a wire from the bow and stern to the top of a mast in the middle of the vessel. That caused the bow and stern to lift and helped reduce hogging.
Hold —-The inside of a hull; cargo space.
Hold Beams —-Structural members placed in a hold, similar to deck beams, but having no plating or planking on them.
Holder-On —-One who “backs up” or “holds on” the head of a rivet while the point is being “driven”, or upset.
Horn —-To line or square-up; also, part of a cleat.
Hull —-The body of a ship, including shell plating, framing, decks,bulkheads.
I-Beam —-A structural shape with cross section resembling the letter I.
Inboard —-Inside the ship; toward or nearer the center line.
Inboard Profile —-A drawing of the longitudinal section at centerline of ship.
Inert Gas —-A gas such as carbon dioxide or nitrogen that is used to make an oxygen deficient atmosphere. Inerted tanks are useful for preserving cargo integrity and reducing the explosive potential of cargo tanks.
Inerted —-Implies that a tank is filled with an inert gas.
Innage —- A measurement of liquid cargo in a tank. It is the distance from the top of the cargo to the bottom of the tank. It is the opposite of ullage.
Inner Bottom —-Plating forming the upper surface of the double bottom. Also called tank top.
Inner Shell —-A plated surface or “shell” inside the outer shell plating, used as additional protection in case of collision or other accidents.The space between the inner and outer shells is often used as a storage space for liquid ballast or cargo.
Inserted Packing Red lead —-soaked canvas strips placed between connections that cannot be caulked successfully; stop waters.
Intercostal —-Made in separate parts; between frames, beams, etc.,the opposite of continuous. (Floors are continuous; longitudinal girders are intercostal in most cargo vessels.)
Isherwood System —-A system of building ships in which the main framing is longitudinal or fore and aft, instead of transverse as in ordinary ships.
Jack Staff —-A flag staff at the bow of a ship.
Jetsam —-Items that are thrown overboard from a vessel in distress.Discarded cargo that washes ashore.
Joggle —-An abrupt bend or offset in a plate, bar, or frame to eliminate the use of liners.
Jumbo Barge —-Refers to a barge size. The original wood river barge, was finally standardized at 26′ x 110′ long. That size was determined to be too small and so a new larger size called a ‘jumbo’ was developed and it is 195′ x 35′. The jumbo is sized to fit in a lock with a tow of barges and a tow boat. Inland rivers are supposed to accommodate 12′ of water depth for navigation. The jumbo barges have sides that are about 14′ tall so they can be loaded to 12′ depth and still have some freeboard.
Keel —-The principal fore and aft member of a ship’s frame. The keel runs along the bottom, connecting the stem and stern, and to it are attached the frames of the ship.
Keel-blocks —-Heavy blocks which support the keel of the ship during construction or while on drydock.
Keel, Flat —-The bottom shell strake on centerline of ship.
Keelson, Side —-Fore and aft member placed on either side of, and similar to, the vertical keel.
Keel, Vertical —-Vertical plate used as reinforcement for keel, often called center-keelson.
Kenter Joining Shackle —-A fitting on the vessel anchor chain to connect the swivel to the chain.
Kevel —-A deck fitting used to secure a line or a cable to a vessel
King Post —-A stub mast, outboard from center line, used to carry cargo booms; king posts also serve as ventilators.
Knot —-A tie in a line (for instance a square knot). A nautical mile. (About one and one-seventh statute miles.)
Knuckle Plate —-A plate bent to form a knuckle. A knuckle is a rounded corner usually found on the bottom of a vessel. It is believed that if a vessel contacts the river bank, a vessel with rounded ‘knuckle’ plates can be dislodged easier than one that has sharp corners.
Kort Nozzles —-A steel tube that surrounds a propeller, directing the water and improving efficiency.
Ladder —-Inclined steps, used aboard ship in place of “stairs.”
Lap —-A joint in which one part overlaps the other, thus avoiding the use of a butt strap; also, the amount of overlap.
Larboard —-The original name for the left side – the port side. Too much confustion with starboard and it had to be changed.
Launching —-The operation of placing a hull in the water by allowing it to slide down on greased skids, called launching ways.
Laying Out —-Marking plates or shapes, for shearing, punching, etc.
Lazarette —-Ship’s storeroom between decks.
Left Side of A Vessel —-Today the left side is the Port side. As a memory aid, remember that port wine is red and so left is red. Starboard is green and it is the right side. But it hasn’t always been that way. Port used to be ‘larboard’. However there was too much confusion with the word starboard and it was changed to port.
Left step —- Sailors were superstitious and it was considered to be bad luck to make the first step on deck with the right foot.
Left Length Between Perpendiculars—-The length of a ship measured from the forward perpendicular to the after perpendicular.
Length Over All —-The length of a ship measured from the extreme forward end to the aftermost point of the stern.
Lift —-To make a template from measurements taken from the job.
Lightening Hole —-A hole cut in a member to reduce its weight.
Limber Hole —-A small hole cut in a plate near the bottom to permit the passage of water or cargo.
Liner —-A flat or tapered strip of steel placed under a plate or shape to bring the member in line with another which it overlaps. A filler.
Lines —-The form of a ship as represented by its moulded surface.
List —-To lean over to one side.
Load Waterline —-Line of surface of water on a ship when loaded to designed draft.
Loftsman —-A workman in the mold loft, who lays down ship lines and makes templates.
Longitudinal —-A shell, deck, or bulkhead stiffener running fore and aft.
Lug Pad —A projection on deck with hole for fastening a block flora lead.
Main Deck —-Usually the deck immediately below the shelter or weather deck.
Manhole —-A hole cut in a bulkhead, tank top, etc., to allow the passage of a man.
Margin Plate —-The outboard row of plates of the inner bottom, connecting to the shell plating to the bilge.
Marlinspike —-A pointed tapering tool which is used in separating strands of rope or cable in splicing.
Mast —-A large long spar, placed nearly vertical on the center line of a ship.
Mess Room —-A dining room for officers or crew.
Midship —-At or near the middle point of a ship’s length.
Midship Section —-A cross section through the ship, midway between the forward and after perpendiculars.
Mold Loft —-A shed or building with large, smooth floor on which the lines of a ship can be drawn to full scale.
Mooring —-Securing a ship in position by several lines or cables,so that she cannot move or swing; anchoring.
Mooring Pipe —-A casting which prevents chafing of mooring lines passing through bulwark plating.
Mould or Mold —-A light pattern of a part of a ship usually made of thin wood or paper. Also called a template.
Nautical mile —-6,085 feet (6 feet = 1 fathom) (120 fathoms = 1 cable)
Net Tonnage —-A figure obtained by making deduction from the gross tonnage for space not available for carrying cargo.
Oakum —-Untwisted fibers of old rope treated with a composition of resin and pitch, used to fill seams of wooden decks.
Offset —-To move out of line or position.
Offsets —-A table of moulded dimensions for waterlines, decks, etc.
Oil Tight —-Sealed by welding or caulking to prevent oil leakage. Steel barges are welded and tested to be air tight. Tank barges are inspected and tested to confirm that they do not leak. When oil or chemical barge hulls are repaired the USCG sends an inspector to confirm that the repair is done properly and that the welds are air tight. To prove air tight, the hull is pressurized with compressed air and a soap mixture is applied to the outside. That is called an air-test.
Old Man —-A rig for holding a drilling machine.
On Board —-On or in the ship.
On Deck —-On the upper deck; in the open air.
Outboard —-Away from the centerline, towards the side of a ship.
Overboard —-Outside; over the side of a ship, into the water.
Overhang —-That portion of the hull which is over and unsupported by the water.
Oxter Plate —-Bent shell plate which fits around upper part of stern post; also called tuck plate.
Packing —-Material which is placed between plates or shapes to make them watertight; wooden blocks and wedges which support a ship on sliding ways; spacers.
Pad Eye —-An eye located on deck which is used for fastening cables or on the hull for hanging tires or an attachment for hanging a block and fall for lifting the propeller or rudder.
Painter —-A rope used to secure a boat to anything.
Painting a vessel hull —-Vessels must be removed from the water to apply coatings. This vessel is on a drydock.The painter is using an air-less paint system. The paint is under very high pressure (1,000 lbs or more). The coating protects the steel hull from corrosion.
Palm —-Flattened top portion of rudder stock (for bolted connection). Also, a flat surface at the end of a strut or stanchion.
Panama chock —-A steel casting used for line handling – from one vessel to another vessel or to the dock. Developed for use in the Panama canal(?).
Panting —-An in-and-out movement of plating; to pulsate or throb. Panting may be caused by the lift and fall of a ship in a seaway, or by engine vibration.
Pay —-To caulk a seam. ‘the devil to pay’ refers to caulking a really deep or otherwise difficult seam.
Peak —-A narrow compartment at either end of a vessel.
Pillar —-A vertical member or column which provides support to a deck girder. (Also termed a stanchion.)
Pilot House —-An enclosed place in which the main steering wheel,controls, engine room, telegraph, etc., are located. A wheel house.
Pintle —-A pin on which a rudder hinges.
Pitch —-Spacing; as of rivets or gear teeth. Also a tar based material used to seal planks on wood vessels.
Planking —-Wood covering for decks, etc.
Plating —-The plates of a hull, a deck, a bulkhead, etc.
Plimsoll Mark —-A mark placed on the ship’s side to indicate maximum allowable draft.
Pontoon Hatch Cover —-A steel box-shaped member sometimes used in place of hatch beams to close in a cargo hatch.
Poop —-The after, upper portion of the hull, often containing the steering gear.
Poop Deck —-The first deck above the shelter deck at after end of a vessel.
Port —-A harbor; or opening in the side of a ship. The left hand side of a ship (looking toward the bow.) Originally called larboard. Associated with the red marking light. (think – port wine is red, so port side has the red light)
Porthole —-A circular opening in the ship’s side such as a window(see airport).
Press break —-A hydraulic or mechanical device for bending and shaping steel plate. In shipyards the plate is usually shaped cold. Plates bent in a press may be referred to as ‘shaped’ or ‘flanged’ plate.
Profile —-A side elevation of a ship’s form.
Propeller —-A rotating device which drives a ship through the water. Also see cycloidal propulsion system See the Propeller page for propeller information.
Propeller Post —-The forward post of stern frame, which is bored for propeller shaft.
Propeller Shaft —-Rotating bar by means of which the engine turns the propeller.
Quarters —-Living or sleeping rooms.
Rabbet —-A depression or offset designed to take some other adjoining part; as for example, the rabbet in the stem to take the shell plating.
Rail —-The upper rounded edge of the bulwarks.
Railway —-An inclined slope fitted with railroad track. A carriage is lowered down the track into the water, the vessel is floated over the carriage and both are brought up the slope until the vessel is drawn out of the water. Requires a very stout winch to pull the carriage up the slope.
Rake —-Slope aft of a mast, king post or stack.
Reaming —-Enlarging a rivet hole by means of a revolving, cylindrical, slightly tapered tool with cutting edges running along its sides.
Reeve —-To pass the end of a rope through a pulley, etc.
Reverse Frame —-An angle bar or other shape riveted to the inner edge of a transverse frame as reinforcement.
Ribband —-A fore and aft steel strip or heavy batten which is used to temporarily align the transverse frames after erection.
Rigging —-Ropes, wire ropes, lashings, masts, booms, etc.; also, the handling and placing on board the ship of heavy weights and machinery.
Rivet —-A short round metal connection used to fasten two or more members together by clinching after being heated red hot.
Rope —-A line that is attached to a bucket. Everything else on a sailing vessel is a line, not a rope. The halliard for instance is a line that raises the sail and the sheet is a line pulls in the boom.
Roll —-To impart curvature to a plate. Also, the motion of the ship from side to side, alternately raising and lowering each side of the deck.
Roller Chock —-(See Chock Roller.)
Rose Box —-A screen or strainer placed around the end of a bilge suction pipe.
Rudder —-A flat piece or structure of wood or metal attached upright to the sternpost (or in single screw-vessels,to the rudder post) of a vessel by hinges, or pintles and gudgeons, so that it can be turned, as by a tiller, causing the vessel’s head to turn in the same direction, because of the resistance offered to the water by the rudder.
Rudder Post —-After post of stern frame to which the rudder is hung. (Also called stern post.)
Rudder Stock —-The shank of a rudder which extends through shell upward to the steering engine.
Rudder Stop —-Lug to limit the swing of the rudder.
Sagging —-Straining of the ship which tends to make the middle portion lower than the bow and stern. This is the opposite of hogging.
Samson Post —-A heavy vertical post which supports cargo booms; king post.
Scantlings —-The dimensions of various shapes.
Scarf —-To thin out or taper a corner or edge of a plate or shape to make a lap. A joint in a stem, bar keel or stern frame.
Screen Bulkhead —-A bulkhead, usually placed between the engine room and boiler room, which is fire proof, dust proof, and gas tight.
Scupper —-A deck drain.
Scupper Pipe —-A pipe which drains water from scuppers throughout the side of a ship.
Scuttle —-A very small hatch; a manhole.
Sea Chest —-A compartment through which sea water is admitted or discharged.
Seam —-A riveted or welded plate edge connection. A riveted seam overlaps; welded seam may or may not overlap.
Serrated frame—-Sometimes pieces of an angle iron are cut to allow for ventilation, reduce weight or as a shortcut that saves material in the vessel construction. These cutouts may be spaced regularly – every few inches or so and the frame is called a serrated frame.
Set —-Metal mold or template for use on bending slab.
Set Iron —-A bar of soft iron used on bending slab to give shape of frames.
Shaft Alley —-A casing (large enough in which to walk), covering the propeller shaft and extending from engine room to after peak.
Shaft Tunnel —-(See Shaft Alley.)
Shape —-A bar of constant cross section, such as a channel, T-bar,angle bar, etc. Also, to impart curvature to a plate or other member.
Shear Line —-A line at which a shearing cut is to be made.
Shears —-A large machine for cutting plates and shapes.
Sheer —-Curvature of deck in a fore and aft direction as seen in profile.
Sheer Strake —-The top full course of side shell plating.
Sheet Line —-The line (not a rope) that pulls in the boom that has a sail attached. By controlling the sheet, the boom is adjusted to maximum efficiency for the conditions at hand.
Shell Expansion —-A plan showing details of all shell plating and shell longitudinals. (Longitudinals would appear only on tankers)
Shell Landings —-Points on the frames where the edges of shell plates are to be located.
Shell Plating —-The plates forming the outer skin of the hull.
Shelter Deck —-A continuous superstructure deck above the freeboard deck.
Shore —-A temporary brace or prop.
Side Thruster —-A propeller in a tube that is mounted through the hull. They are particularly handy for maneuvering by providing side thrust.
Sight Edges —-Visible edges of plating (outside shell and above decks.)
Skylight —-An opening in a deck to give air and light to the compartment below it.
Sliding Way —-That part of launching way which moves with the ship.
Slop Chute —-Chute for dumping garbage overboard.
Sounding Pipe —-Vertical pipe in oil or water tank used in measuring depth of liquid in tank.
Spar —-Long, round member such as mast or boom; part of rigging.
Stability —-The tendency of a ship to remain upright.
Staging —-Planks or scaffolding on which to stand when working on sides or under decks.
Stanchion —-A pillar or upright post.
Starboard —-The right hand side of a ship, looking forward. This is oriented with the green marking light.
Stay —-A guy line.
Stealer —-A plate extending into an adjoining strake as at the end of a drop strake.
Steering Gear —-Apparatus for controlling the rudder.
Stem —-Forging, casting, or plating forming extreme bow of ship and extending from keel to forecastle deck.
Step —-To set in place (as applied to a mast); also, a socket for the end of a must; a support for the fixed or “hinged” end of a boom.
Stern —-The after or back end of a vessel.
Stern Frame —-A large casting or forging attached to the after end of a hull to form the ship’s stern. It includes rudder post, propeller post, and aperture for the propeller.
Stern Tube —-A long bushing or bearing through the stern to support the end of a propeller shaft.
Stiffener —-An angle bar, T-bar, channel, etc., used to stiffen plating of a bulkhead or other member.
Stool —-A support for a propeller shaft bearing in the shaft alley.A foundation, etc.
Stop Water —-Canvas and red lead, or other material, fitted between two metal parts to make a watertight joint.
Stowage —-A support or fastening for any gear, as, anchor or boat stowage.
Strake —-A fore and aft course, or row, of shell or other plating
Stringer —-A fore and aft member used to give longitudinal strength. Depending on location, these are called hold stringers, bilge stringers,side stringers, etc.
Stringer Deck —-The strake of deck plating which contacts the shell.
Stringer Plate —-A deck plate at the outboard edge of deck connected to the shell of a ship with an angle or a welded joint.
Strong Back —-A supporting girder for a hatch cover; a rig used in straightening bent plates; a bar for locking cargo ports.
Strut —-A support for a propeller tail shaft (used on ships with more than one propeller).
Sump —-A depession or low place in a tank – especially a tank barge. The cargo pipeline is placed very near the bottom of the sump. The sump is placed so that liquid cargo drains into it when the vessel is discharged.
Super structure —-Deck houses, etc., which are located above shelter deck.
Swash Plate —-A baffle plate in a tank which prevents excessive surging of a liquid.
Swivel Assembly —-A intermediate ‘link’ on a anchor chain assembly that allows the chain to turn. It is connected to the anchor joining ling and the kenter.
Syncrolift (TM) —-A platform fitted with winches and anchor chain.The winches lower the platform into the water, the vessel is floated on and the platform is raised. Sometimes the vessel can be rolled to a repair station on railroad track.
Tail Shaft —-A short section of a propeller shaft extending through the stern tube and carrying the propeller.
Tank barge —-A vessel designed for carrying -usually- liquid cargo.Often has an engine and a pump to assist in transferring cargo, but does not have main propulsion equipment.
Tank Top —-The plating over the double bottom.
Tankerman —-The official USCG classification of the person that supervises the transfer of cargo between vessels or vessel and shore. There are different grades of expertise A, B, C, D and LFG – relating to the degree of hazard in relation to fire.
Tee-bar —-A structural shape with cross section resembling the letter T.
Template —-A mold or pattern. Sometimes made of plywood or paper.
Thrust Bearing —-A bearing or block to resist end thrust. A bearing on propeller line shaft which relieves the engine from the driving force of the propeller.
Thwart —-A seat in a lifeboat. Something that runs transverse.
Tiller —-An arm, attached to rudder head, which operates the rudder.
Tow Boat —-A vessel generally used on inland rivers to push barges. The tow boat pushes a tow of barges and it has a flat bow to face up to the barges.
Tow Knee —-On a tow boat (so named because they push a bunch of barges called a ‘tow’) there are almost always 2 vertical supports for the barges to rest on. These are called tow knees and they have stairs built in for the crew to get to the barges.
Tractor propulsion —-A system of vertical blades used to propel a vessel in the water. Used on some harbor tugs and ferries. Made by Volith. Sometimes called a cyclonic system in reference to the way the blades are mounted under the hull, and the way they turn.
Transom —-The main frame at the rudder stock (cant frames usually radiate from the transom frame). The very last (most aft) plate on a welded vessel.
Transverse —-Athwartships; at right angles to the keel.
Transverse Frames —-Athwartship members forming the ship’s “ribs.”Also see Buck frame.
Travelift (TM) —-A device for lifting vessels out of the water. Has rubber tires and slings. The slings are lowered in the water, the vessels floated in and lifted out of the water with cable winches. Once raised, the vessel can be moved to a station, blocked, etc. and the Travelift can return to the slip to move another vessel.
Trick —-A sailor’s duration of time in steering.
Trim —-To shift ballast; to cause a ship to change its position in the water; drag.
Trunk —-A small casing passing through a deck, such as is used for ladders or ventilation.
Tug Boat —-A relatively small vessel with a big engine used to 1/ assist ships when the ships are being docked 2/ tow barges by pulling them with a cable in the ocean. Tug boats have a pointed bow, but are not especially designed for speed. Tug boats can face up to a vessel to push it or they can pull with a cable or they can make up on a vessel on the side, referred to as being ‘on the hip’.
Tumble Home —-An inboard slant of a ship’s side above the bilge.
Ullage Hatch —- A small hinged opening on a tank for gaging or sampling cargo. The ullage is the distance from the top of this hatch to the top of the cargo. It is the ‘opposite’ of innage.
Uptake —-Connection between boilers and smokestack.
Vapor Header —-A pipeline connected to the top of a cargo tank that channels the displaced tank vapors to a shore side control system.
Vertical Keel —-A row of vertical plates extending along the center of the flat plate keel. It sometimes is called the center keelson.
Voice Tube —-A large (about 1″ to 1.5″ OD) speaking tube that goes from one operating station to another. Very effective. They would have a whistle so that – for instance- when the bridge wanted to call the engine room they would blow in the tube. The whistle would notify the personnel at the other end that they were wanted.
Void Tank —-A watertight space that does not carry ballast or cargo. For flotation.
Water Line —-Any one of certain lines of a ship parallel with (and at various heights above) the base line. In half-breadth plans the waterlines are smooth curves showing the shape of the ship; in profile plans they are projected as straight lines
Watertight —-So riveted, caulked, or welded as to prevent the passage of water.
Waterway —-A narrow passage along the edge of a deck for drainage. A gutter.
Ways —-Timbers, etc., on which a ship is built or launched. (See: Launching.)
Weather Deck —-A deck exposed to the weather.
Web —-The vertical portion of a beam, the thwartship portion of a frame, etc.
Web Frame —-A frame with a deep web.
Welding —-Fusing together two or more members with electric arc or by other means. Welding is a process that can be done with coated electrodes, called stick welding. Modern electrodes have a coating that vaporizes during the weld process. That vaporized gas drives oxygen out of the molten weld puddle allowing the metals to be joined without holes. There are other weld processes such as gas shield wire welding, etc.
Well —- A cofferdam or a sump in the double bottom.
Wheel —-Nickname for propeller; steering gear control.
Winch —-A small hoisting device; used in pulling lines or cables in handling cargo. Can be hand, air motor, electric, steam, engine, etc…powered.
Windlass —-A machine used to hoist the anchors by winding in the anchor chain.
Wind Scoop —-A device used to divert air into a compartment of a ship.
Zee-bar —-A structural shape with a cross section resembling the letter Z.