General Terms and Definitions for Ships




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.


Toward, at, or near stern.


 Nearer stern.


 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 watertight 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 deckhouse, for light or ventilation.


At or near the midship section of the ship.


 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.

Angle Clip

 A short piece of angle bar.

Angle Collar

A ring made of angle bar.


To soften metal by heating and allowing it to cool slowly.


Zink or aluminium 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.


A recess in which the propeller is located.


To fit together small parts, in making a large section, or part.


Across the ship at right angles to the centreline.


Machinery supplementary to main propulsive units.

Awning Deck

Shade deck above another deck.


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.


A water tight vessel that floats in water. Barges also come in open and closed hopper styles, and with flat decks.


Small marine growth which attaches itself to a vessel’s hull in large numbers, often greatly retarding her speed.



Long strips of wood used in the mould loft for fairing lines; also, wooden protective strips in cargo holds; see hatch battens.


An athwartship member supporting a portion of a deck. Also, the width of the ship.

Beam Knee

(See Bracket)


Below a deck or decks (corresponding to ‘downstairs’).


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.


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.


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.


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.


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.


A case, box, or stand containing a ship’s compass, adjusting magnets, and a lamp for use at night.


A vertical post used in making fastlines; a bollard.


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.


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.


A single tie post (see bitt).

Booby Hatch

A watertight covering over a deck opening, which is used for a stairway or ladder.


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.


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.


The forward end of a vessel. (Usually the pointed end.)


A spar projecting forward from the bow of a vessel used to attach sails and stays.


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.


To heat and join by means of hard solder (spelter). This may be brass, bronze, or other alloys.


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.


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.


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.


The ship’s side above the weather deck.

Bull Riveting

Driving rivets by squeezing them with a high powered air or hydraulic machine.


A compartment used for the stowage of coal or other fuel.


Ability to float; lifting power when immersed.


The joint formed when two parts are placed edge to edge.


A distance from centreline; 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..

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.


A cast or fabricated deck item, usually round, that is used to thread cables between vessels when they are made-up.


A kitchen on deck.


The athwartship rise or crown of a deck.

Cant Frame

A frame which is not square to the keel line.


A revolving drum, with vertical axis, used for heaving in lines.


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.


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.


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.


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.


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.


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 mould loft.)


The vertical boundary of a hatch or skylight.


A narrow vacant space between two bulkheads. A double watertight bulkhead.


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.




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.


A subdivision of space or room in a ship.


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.


Overhang of the stern of a ship.


To taper a hole for a flush rivet or bolt.


The hood shaped top of a ventilator pipe.


A form on which bows, etc., are assembled. The support in which a ship rests during launching; a launching cradle.


A pipeline that crosses over a tank providing a transit for cargo without tying into the vessel.

Cycloidal 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’.


A crane arm used in handling small boats, lifeboats, stores, gear, etc.

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.


The total weight of cargo, fuel, water, stores, passengers and crew, and their effects, which a ship can carry.


A part of a ship corresponding to the floor of a building.


A shelter built on deck.


Inclination of shipways to provide for launching.

Deep Tank

A deep compartment usually extending from tank top to lower deck.


A device for hoisting heavy weights, cargo, etc.


A tool for forming a rivet head (applied to rivet dies).


The total weight of the ship when afloat, including everything on board, (equals weight of water displaced.) Usually expressed in long tons.


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.


The amount the stern end of the keel is below the bow end when the ship is afloat, but not on an even keel.



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.

Drift Pin

A small tapered tool used in aligning holes in adjacent members.

Drop Strake

A strake discontinued near the bow or stern.


A watertight vessel fitted with pumps and valves usually built in u-shaped. The valves are opened, the vessel sinks, the vessel to be docked is pulled over the dry-dock deck, the valves are closed and the pumps are started, as the dry-dock becomes more buoyant, dry-docking the vessel to be repaired.


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


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.


A fitting through or over which a rope, line, etc., maybe led so as to change its direction without excessive friction.


Plate or casting used to preserve streamline flow past hull structure or propeller hub.


Six feet.


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.


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.


Casing top over boiler room.

Fidley Hatch

A hatch over boiler room.


The bust, often of a woman, on the bow of a vessel, just under the bowsprit.


Flagpole at stern of ship; ensign staff.


A part of a plate or shape at, or nearly at, right angles to main port; to bend over to form an angle.


The sudden widening of the shell at top near the bow.


A small partial deck (built level) without curvature.


The lower portion of a transverse frame, usually a vertical plate extending from center line to bilge, and from inner to outer bottom.


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 deckhouses at or near centreline of ship.


A hull form forward of the midship section.


The forward upper portion of the hull, sometimes used for the crew’s quarters.


The part of the keel which curves and rises to meet the Stem.


The large compartment or tank, at the bow in the lower part of the ship.

Forepeak Bulkhead

Collision bulkhead; bulkhead nearest bow.


Steel worked to special shape by hammering while red hot.


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.


Supports for boilers, engines, and auxiliary machinery.

Foundations, Auxiliary

Supports for small machinery, such as winches, condensers, heaters, etc.


Ribs forming the skeleton of a ship.


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.


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.


A smokestack of a vessel.


A heater or large forge for heating plates or shapes for bending; to bend by heating in furnace.


A cook room or kitchen.

Galley Dresser

A cook’s work table.


Coating metal parts with zinc for protection from rust.


A passageway, a ladder, or other means of boarding a ship.

Garboard Strake

The course of plates next to the keel of a ship.


Packing of canvas composition, or other material, used in making a tight joint.


Fore and aft stiffening member for deck or bottom shell.


Any expanded length.

Grab Rods

Bent rods welded to bulkheads or ship’s side to form a ladder.


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.


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.


Bosses on stern post drilled for pins (Pintles) on which rudder swings.


The junction of deck and shell at top of sheer strake.

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 indicates 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.


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.


A large rope used in towing or mooring.


The bow plate on a vessel that is made of thick steel plate.


The inclination of a vessel to one side.


Straining of the ship which tends to make the bow and stern lower than the middle portion.


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.


One who ‘backs up’ or ‘holds on’ the head of a rivet while the point is being ‘driven’, or upset.


To line or square-up; also, part of a cleat.


The body of a ship, including shell plating, framing, decks, bulkheads.


A structural shape with cross section resembling the letter I.


Inside the ship; toward or nearer the centre line.

Inboard Profile

A drawing of the longitudinal section at centreline 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.


Implies that a tank is filled with an inert gas.


 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 storages pace for liquid ballast or cargo.

Inserted Packing Red lead

soaked canvas strips placed between connections that cannot be caulked successfully; stop waters.


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.


Items that are thrown overboard from a vessel in distress. Discarded cargo that washes ashore.


An abrupt bend or offset in a plate, bar, or frame to eliminate the use of liners.


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.

Keel, Flat

The bottom shell strake on centreline 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 centerkeelson.


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; kingposts also serve as ventilators.


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.


Inclined steps, used aboard ship in place of ‘stairs.’


A joint in which one part overlaps the other, thus avoiding the use of a butt strap; also, the amount of overlap.


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.


Ship’s storeroom between decks.

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.


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.


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.


The form of a ship as represented by its moulded surface.


To lean over to one side.

Load Waterline

Line of surface of water on a ship when loaded to designed draft.


A workman in the mold loft, who lays down ship lines and makes templates.


A shell, deck, or bulkhead stiffener running fore and aft.

Lug Pad

A projection on deck with hole for fastening a block fora lead.

Main Deck

Usually the deck immediately below the shelter or weather deck.


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.


A pointed tapering tool which is used in separating strands of rope or cable in splicing.


A large long spar, placed nearly vertical on the center line of a ship.

Mess Room

A dining room for officers or crew.


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.


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.

Net Tonnage

A figure obtained by making deduction from the gross tonnage for space not available for carrying cargo.


Untwisted fibres of old rope treated with a composition of resin and pitch, used to fill seams of wooden decks.


To move out of line or position.


A table of moulded dimensions for waterlines, decks, etc.

Oil Tight

Sealed by welding or caulking to prevent oil leakage.

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.


Away from the centreline, towards the side of a ship.


Outside; over the side of a ship, into the water.


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.


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.


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 airless paint system. The paint is under very high pressure (1,000 lbs or more). The coating protects the steel hull from corrosion.


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.


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.


A narrow compartment at either end of a vessel.


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.


A pin on which a rudder hinges.


Spacing; as of rivets or gear teeth.


Wood covering for decks, etc.


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.


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.


A harbour; or opening in the side of a ship. The left hand side of a ship (looking toward the bow.) Originally called larboard.


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.


A side elevation of a ship’s form.


A rotating device which drives a ship through the water. Also see cycloidal propulsion system

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.


Living or sleeping rooms.


A depression or offset designed to take some other adjoining part; as for example, the rabbet in the stem to take the shell plating.


The upper rounded edge of the bulwarks.


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.


Slope aft of a mast, kingpost or stack.


Enlarging a rivet hole by means of a revolving, cylindrical, slightly tapered tool with cutting edges running along its sides.


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.


A fore and aft steel strip or heavy batten which is used to temporarily align the transverse frames after erection.


Ropes, wire ropes, lashings, masts, booms, etc.; also, the handling and placing on board the ship of heavy weights and machinery.


A short round metal connection used to fasten two or more members together by clinching after being heated red hot.


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.


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.


Straining of the ship which tends to make the middle portion lower than the bow and stern.

Samson Post

A heavy vertical post which supports cargo booms; kingpost.


The dimensions of various shapes.


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.


A deck drain.

Scupper Pipe

A pipe which drains water from scuppers throughout the side of a ship.


A very small hatch; a manhole.

Sea Chest

A compartment through which sea water is admitted or discharged.


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.


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.)


A bar of constant cross section, such as a channel, Tbar, 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.


A large machine for cutting plates and shapes.


Curvature of deck in a fore and aft direction as seen in profile.

Sheer Strake

The top full course of side shell plating.

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.


A temporary brace or prop.

Side Thruster

A propeller in a tube that is mounted through the hull. They are particularly handy for manoeuvring by providing side thrust.

Sight Edges

Visible edges of plating (outside shell and above decks.)


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.


Long, round member such as mast or boom; part of rigging.


The tendency of a ship to remain upright.


Planks or scaffolding on which to stand when working onsides or under decks.


A pillar or upright post.


The right hand side of a ship, looking forward.


A guy line.


A plate extending into an adjoining strake as at the end of a drop strake.

Steering Gear

Apparatus for controlling the rudder.


Forging, casting, or plating forming extreme bow of ship and extending from keel to forecastle deck.


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.


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.


An angle bar, Tbar, channel, etc., used to stiffen plating of a bulkhead or other member.


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.


A support or fastening for any gear, as, anchor or boat stowage.


A fore and aft course, or row, of shell or other plating


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.


A support for a propeller tail shaft (used on ships with more than one propeller).

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.


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.


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.


A structural shape with cross section resembling the letter T.


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.


A seat in a lifeboat. Something that runs transverse.


An arm, attached to rudder head, which operates the rudder.

Tow Boat

A vessel generally used on inland rivers to push 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 Voith. Sometimes called a cyclonic system in reference to the way the blades are mounted under the hull, and the way they turn.


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.


Athwartships; at right angles to the keel.

Transverse Frames

Athwartship members forming the ship’s ‘ribs. ‘Also see Buck frame.


A device for lifting vessels out of the water. Has rubber tires and slings. The slings are lowered in the water, the vessel is 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.


A sailor’s duration of time in steering.           


To shift ballast; to cause a ship to change its position in the water; drag.


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  3/

Tumble Home

An inboard slant of a ship’s side above the bilge.

Ullage Hatch

 A small hinged opening on a tank for gauging 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.


Connection between boilers and smokestack.

Vapour Header

A pipeline connected to the top of a cargo tank that channels the displaced tank vapours 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 speaking tube that goes from one operating station to another. Very effective.

Void Tank

A watertight space that does not carry ballast or cargo. For floatation.

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


So riveted, caulked, or welded as to prevent the passage of water.


A narrow passage along the edge of a deck for drainage. A gutter.


Timbers, etc., on which a ship is built or launched. (See Launching.)

Weather Deck

A deck exposed to the weather.


The vertical portion of a beam, the athwartship portion of a frame, etc.

Web Frame

A frame with a deep web.


Fusing together two or more members with electric arc or by other means.


 A cofferdam or a sump in the double bottom.


Nickname for propeller; steering gear control.


A small hoisting device; used in pulling lines or cables in handling cargo. Can be hand, air motor, electric, steam, engine, etc. powered.


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.


Disclaimer: Author unknown

Ash Breeze - oar power

Baboon watch - The person standing watch while the rest of the crew is on leave, usually the apprentice.

Beating the booby - swimming the arms in cold water to increase circulation

Bird's nest - tangled rope

Black gang - engine room crew

Blood money - payment to an agent for the recruitment of a seaman

Bluenose - Novascotiaman

Brass hat - naval officer with rank of commander or above

Bricklayer's clerk - a sailor who acts like he above it all

Cape Horn fever - the feigned illness of a malingerer

Catch a crab - an oar caught aback when rowing

Clearing for Guam - getting under way to nowhere

Deadeye watch - 4 am to 8 am watch

Dead horse - sailor's debt for advance wages

Dock walloper - a person who walks around the dock "checking things out"

Dogs running before their master - the heavy swell in advance of the hurricane

Dutch courage - fearlessness brought on by strong drink

Dying man's dinner - food quickly prepare during an emergency

Fourth class liberty - watching the shore when confined to the ship

Fuel fever - fuel oil in short supply

Galley news - gossip and rumor

Gongoozler - a person who stands around the waterfront with his hand in his pockets, watching other people do things

Graveyard watch - 12 - 4 am

Granny knot - failed, unseamanlike attemp at a square knot

Half seas over - just short of being drunk

High pressure hat - an officer's cap

Homeward bound stitches - excessively long sewing stitches, taken in a hurry

Hot bunk - a bunk used successively by more than one sailor

Irish hurricane - a flat calm

Irish pennant - loose irregular end

Jackass brig - a variation of the brigatine rig

Jimmy the one - first lieutenant or executive officer

Limer juicer (also Limey) - British vessel or sailor

Metal or Iron, Mike - mechanical self steering

Nantucket sleigh ride - a whaleboat towed out of control by a harpooned whale

North River Jibe - uncontrolled standing jibe

Blowing up and down - a dead calm

Paper jack - a licensed captain seen to be incompetent

Pig boat - a submarine

Rocks and Shoals - the portion of naval regulations concerning punishment for crimes

Rope -Yarn Sunday - an afternoon off devoted to washing and sewing clothes

Sailor's blessing - a curse

Seaman's digrace - a fouled anchor

Soldier - a sailor who dodges work

Soldier's breeze - a fair, light wind

Tom Cox's traverse - dodging work by making frequent trip to the scuttlebutt "searching" for the proper tool, etc.


Abaft: On the after side of. Further towards the stern.

Aboard: On board. In, into or inside a vessel. Close alongside.

Abyss: That volume of ocean lying below 300 fathoms from surface.

Accommodation Unit/Floatel - normally a semisubmersible or jackup (See Jackup), equipped with cabins, catering facilities and office space for up to 800 persons. The installation is normally used for the accommodation and catering for personell constructing or operating a fixed production platform. An accommodation unit may also be equipped with workshops and/or storage facilities.

Adrift: Unattached to the shore or ground and at the mercy of wind and tide. Colloquially used to mean missing from its place; absent from place of duty; broken away from fastening.

Aframax: An oil tanker of 75,000-115,000dwt. Certain external statistical compilations define an "Aframax Tanker" slightly differently, some going as high as 125,00 dwt and others as low as 70,000 dwt. External data used in this prospectus has been adjusted so that the definition of "Aframax Tanker" is consistent throughout.

Against the Sun: Anti-clockwise circular motion. Left-handed ropes are coiled down in this way.

Alongside: Close beside a ship, wharf or jetty.

Altar: Step in a dry dock, on which lower ends of shores rest.

Amok: Homicidal frenzy that sometimes affects Malayans and other eastern peoples.

Anchorhandling Tug - AHT - ship carrying out tasks such as the placing or moving of anchors, as well as towing drilling installations and barges etc. May double as a supply vessel and is in such cases termed Anchorhandling Tug/Supply (AHTS).

Anchor Ice: Ice, of any form, that is aground in the sea.

ANNUAL SURVEY: An annual inspection of a vessel by a classification society surveyor to ensure that the vessel meets the standards of that society.

Apeak: Said of anchor when cable is taut and vertical.

A-stay: Said of anchor cable when its line of lead approximates a continuation of line of fore stay.

Athwart: Across. Transversely.

A-trip: Said of anchor immediately it is broken out of the ground.

Avast: Order to stop, or desist from, an action.

Awash: Water washing over.

ABS - American Bureau of Shipping - American classification society.

ACOT - Advisory Committee on Offshore Technology

ACP - Area Contingency Plan

ADB - African/Asian Development Bank

AFRA - Average Freight Rate Assessment - average costs for the freight of oil with tankships. Calculated by the Worldscale Association in London. based on an ongoing registration of all freightrates at particular points in time.

AHT - Anchorhandling Tug - vessel employed in the offshore field moving anchors and performing towing operations.

AHTS - AHT which is also a combined supplyvessel.

AID - Agency for International Development - US organization for civilian aid programmes.

AIMS - American Institute of Merchant Shipping - the American shipowners' association for the major part of the privately owned tonnage.

ALAMAP - Associac¢n Latinamericano de Armadores - Latin-American Shipowners' Association (established in March 1963).

ALU-TUCP - Philippine Seafarers' Union, member of TUCP (Trade Union Council of the Philippines).

AMOSUP - Associated Marine Officers' and Seamen's Union of the Philippines - Filipino union for officers and crew.

AMVER - Automatic Mutual-Assistance Vessel Rescue System - American warning system for international shipping.

ASEAN - Association of South East Asian Nations - Indonesia, Malaysia, the Philippines, Singapore.

ASF - Asian Shipowners' Forum - shipowners' association for East Asia and Oceania.

ASO - Arbeidsgiverforeningen for Skip og Offshorefartoyer - The Employers' Organization for Ships and Offshore Installations (Oslo).

AWES - Association of Western European Shipbuilders

Ballast: A vessel is in ballast when it is steaming without cargo, and is instead loaded down with sea water for stability. Given that oil production is concentrated in certain parts of the world, a vessel will generally spend a significant amount of time "ballasting" as it returns from discharge port to load port.

Bareboat Charter: The leasing of an empty ship for a specified period of time for a specific fee in this arrangement, the ship owner virtually relinquishes all rights and responsibilities in respect of the vessel and the charterer becomes the de facto ("disponent") owner for this period. The charterer is generally responsible for all operating expenses including crewing and insurance.

Barque: Sailing vessel with three or more masts: fore and aft rigged on aftermast, square rigged on all others.

Barquentine: Sailing vessel with three or more masts. Square rigged on foremast, fore and aft rigged on all others.

Barratry: Any wrongful act knowingly done by the master or crew of a vessel to the detriment of the owner of either ship or cargo; and which was done without knowledge or consent of owner or owners.

Bar Taut: Said of a rope when it is under such tension that it is practically rigid.

Beams Ends: Vessel said to be "on her beam ends" when she is lying over so much that her deck beams are nearly vertical.

Bear Off: To thrust away; to hold off. Order given to bowman of boat when he is required to push boat's head away from jetty, gangway or other fixture at which boat is alongside. Order given, also, when it is required to thrust away, or hold off, an approaching object.

Before the Mast: Said of a man who goes to sea as a rating, and lives forward. Forward of a mast.

Belay: To make fast a rope by turning up with it around a cleat, belaying pin, bollard, etc. Often used by seamen in the sense of arresting, stopping or canceling; e.g. "Belay the last order'.

Bergy Bits: Pieces of ice, about the size of a small house, that have broken off a glacier, or from hummocky ice.

Berth: Place in which a vessel is moored or secured. Space around a vessel at anchor, and in which she will swing. An allotted accommodation in a ship. Employment aboard a ship. To berth a vessel is to place he in a desired or required position.

Beset: Said of a vessel when she is entirely surrounded by ice.

Bleed the Monkey: Surreptitiously to remove spirit from a keg or cask by making a small hole and sucking through a straw.

Boat: Small craft not normally suitable for sea passages but useful in sheltered waters and for short passages.

Bone: Foam at stem of a vessel underway. When this is unusually noticeable she is said to "have a bone in her teeth".

Booby Hatch: Sliding cover that has to be pushed away to allow passage to or from a store room, cabin of small craft, or crew's quarters.

Bound: Proceeding in a specified direction, or to a specified place.

Bouse: To heave, or haul, downwards on a rope. Originally, and strictly, heave meant an upward pull, haul meant a horizontal pull, bouse meant a downward pull: but these distinctions have not survived.

Bowse: To pull downward on a rope or fall.

Brash: Ice broken into pieces, about 6 ft. in diameter and projecting very little above sea level.

Breach: Said of waves that break over a vessel.

Breast: Mooring line leading approximately perpendicular to ship's fore and aft line.

Breast Rope: Mooring rope, leading from bow or quarter, at about right angles to ship's fore and aft line.

Brig: Vessel with two masts and square rigged on both of them.

Brigantine: Originally, a ship of brigands, or pirates. Up to end of 19th century was a two-masted vessel square rigged on fore-mast and main topmast, but with fore and aft mainsail. Latterly, a two-masted vessel with foremast square rigged, and mainmast fore and aft rigged.

Brow: Substantial gangway used to connect ship with shore when in a dock or alongside a wharf.

Bucko: A bullying and tyrannical officer.

Bulkhead: Transverse, or fore and aft, vertical partition in a vessel to divide interior into compartments. Not necessarily water-tight. Increases rigidity of structure, localizes effects of fire and, when watertight, localizes inflow of water.

Bulk Carrier: A ship with single deck designed to carry homogenous loose cargo

Bulk-oil carrier - multipurpose vessel built to carry cargoes of coal as well as oil. Most bulk-oil carriers are reinforced to carry ores and are called OBO-ship (ore/bulk/oil).

Bunker: Fuel oil used to operate a vessel’s engines and generators.

Buoyage: The act of placing buoys. 2. Establishment of buoys and buoyage systems. Applied collectively to buoys placed or established.

Burgoo: Seaman's name for oatmeal porridge. First mentioned in Edward Coxere's Adventures by Sea" (1656)

By the Board: Overboard and by the ship's side.

BEI - Banque Europeenne d'Investissement - The European Investment Bank.

BFI - Baltic Freight Index - an index for bulk freight rates.

BIAC - Business and Industry Advisory Committee - OECD's advisory committee. Opposite to TUAC.

BICC - Bureau International des Chambres de Commerce - International information bureau for Chambers of Commerce.

BIFA - British International Freight Association

BIFFEX - Baltic International Freight Futures Exchange (London) - an exchange for the buying and selling of futures, based on the BFI.

BIMCO - The Baltic and International Maritime Council (Copenhagen)

BIS - Bank for International Settlements (Basel)