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Banner image, Nomenclature of Naval Vessels

Table of Contents
A B C D E F
G H I J K L
M N O P Q R
S T U V W X  Y  Z


--D--

DAGGER
A piece of timber that is fastened to the poppets of the bilgeway and crosses them diagonally to keep them together. Dagger applies to anything that stands in a diagonal position in a fore and aft plane.
DAGGER PLANK
One of the planks which unite the heads of the poppets or stepping-up pieces of the cradle on which the vessel rests in launching.
DAVIT
A device used to lower and raise ship's boats and sometimes for other purposes. The rotary, or most common type, consists of a vertical pillar, generally circular in section, with the upper portion bent in a fair curve and having sufficient outreach to clear the side of the ship plus a clearance. Each ship's boat has two davits, one near its bow and one near its stern; they both rotate, lifting the boat, by means of blocks and falls suspended from the overhanging end, from its stowage position on deck and swinging it clear of the ship's side. This type of davit is usually stepped in a socket attached to the side of the vessel or on the deck next below the boat deck near the side and held in place at the boat deck by a keeper or bearing.
DEAD EYE
See "Blind Pulley".
DEAD FLAT
The midship portion of a vessel throughout the length of which a constant shape of cross section is maintained.
DEADLIGHT
A applied to a port lid or cover; a metal shutter fitted to protect the glass in a fixed or port light. Often incorrectly applied to a fixed light in a deck, bulkhead or shell.
DEAD RISE
The angle which the straight portion of the bottom of the floor of the midship section makes with the base line. It is expressed by the number of inches rise above the base line in the half-beam of the vessel.
DEADWEIGHT
The difference between the light displacement and the full load displacement of a vessel; the total weight of cargo, fuel, water, stores, passengers, and crew and their effects that a ship can carry when at her maximum allowable draft.
DEADWEIGHT CARGO
The number of tons remaining after deducting from the deadweight the weight of fuel, water, stores, dunnage, and crew and their effects necessary for use on a voyage. Also called "useful" or "paying deadweight", "deadload", and "burden".
DEADWOOD
The reinforcing structure built in between the keel and keelson in the after body of a ship or back of the joint between the stem and the keel in the fore body.
DECK
A deck in a ship corresponds to a floor in a building. It is the plating, planking, or covering of any tier of beams above the inner bottom forming a floor, either in the hull or superstructure of a ship. Decks are designated by their location as upper deck, main deck, etc., and forward lower deck, after superstructure deck, etc. The after portion of a weather deck was formerly known as the quarter deck and on warships is allotted to the use of the officers.
DECK BOLT
A special type of bolt used to secure the planks of a wood deck to the frames or deck plating.
DECK, BULKHEAD
The uppermost continuous deck to which all main transverse bulkheads are carried. This deck should be watertight to prevent flooding adjacent compartments if a compartment is bilged.
DECK, FREEBOARD
The deck to which the classification societies require the vessel's freeboard to be measured. Usually the upper strength deck.
DECK HEIGHTS
The vertical distance between the molded lines of two adjacent decks.
DECK HOUSE
A term applied to a partial superstructure that does not extend from side to side of a vessel as do the bridge, poop, and forecastle.
DECK LINE
See "Beam line".
DECK MACHINERY
A term applied to capstans, windlasses, winches, and miscellaneous machinery located on the deck of a ship.
DECK PLANKS, or PLANKING
A term applied to the wood sheathing or covering on a deck. Oregon pine, yellow pine, and teak are most commonly used. The seams between the planks should be thoroughly caulked.
DECK PLATING
A term applied to the steel plating of a deck.
DECK STRINGER
The strip of deck plating that runs along the outer edge of a deck.
DECK, TURTLE
A term applied to a weather deck that is rounded over from the shell of the ship so that it has a shape similar to the back of a turtle. Used on ships of the whaleback type and on the forward weather deck of torpedo boats.
DEEP FLOORS
A term applied to the floors at the ends of a ship which are deeper than the standard depth of floor at amidships.
DEEP TANKS
Tanks extending from the bottom or inner bottom of a vessel up to or higher than the lowest deck. They are fitted with hatches so that they may be used for cargo when the vessel is loaded in lieu of the ballast water carried when the vessel is "light." They are placed at either end or both ends of the machinery space as deemed necessary.
DEEP WATERLINE
The waterline at which the vessel floats when carrying the maximum allowable load.
DEPTH MOLDED
The vertical distance from the molded base line to the top of the uppermost strength deck beam at side, measured at midlength of the vessel.
DERRICK
A device consisting of a kingpost, boom with variable topping lift, and necessary rigging for hoisting heavy weights, cargo, etc.
DESTROYER
A naval vessel of small displacement and high speed, armed with light, rapid-fire guns and deck torpedo tubes, used for convoy and scouting work and as a protection to capital ships [originally "torpedo boat destroyer"]. Larger vessels of this type are called destroyer leaders.
DIAGONAL LINE
A line cutting the body plan diagonally from the frames to the middle line in the loft lay-out and usually a mean normal to a group of frames of similar curvature, representing a plane introduced for line fairing purposes.
DISHED PLATES
Plates, generally of circular shape, which have been furnaced or pressed into a concave form.
DISPLACEMENT
The volume of fluid displaced by a freely floating and unrestrained vessel, the weight of which exactly equals the weight of the vessel and everything on board at the time the displacement is recorded. Displacement is expressed in either cubic feet or in tons of salt or fresh water.
DISPLACEMENT CURVES
Curves drawn to give the displacement of the vessel at varying drafts. Usually these curves are drawn to show the displacement in either salt or fresh water, or in both, the salt water curves being based on 35 cubic feet to a ton and fresh water curves on 36 cubic feet to a ton. Corrections are made from these basic standards for variable density of the water.
DISPLACEMENT, DESIGNED
The displacement of a vessel when floating at her designed draft.
DISPLACEMENT, FULL LOAD
The displacement of a vessel when floating at her greatest allowable draft as established by the classification societies. In warships, an arbitrary full load condition is established.
DISPLACEMENT, LIGHT
The displacement of the vessel complete with all items of outfit, equipment, and machinery on board, but excluding all cargo, fuel, water, stores, passengers, dunnage, and the crew and their effects. Naval and merchant practice differs in one particular; in the former the machinery weights are dry, while the merchant light condition includes the water and oil in the machinery with boilers at steaming level.
DOCK
A basin for the reception of vessels. Wet docks are utilized for the loading and unloading of ships. Dry docks are utilized for the construction or repair of ships.
DOCKYARD
A shipyard or plant where ships are constructed or repaired.
DOG
A short metal rod or bar fashioned to form a clamp or clip and used for holding watertight doors, manholes, or pieces of work in place.
DOG SHORES
Diagonal braces placed to prevent the sliding ways from moving when the shores and keel blocks are removed before launching. Dog shores are the last timbers to be knocked away at a launching. Also called "daggers" or "dagger shores".
DOLLY BAR
A heavy steel bar used to hold against the heads of rivets while the points are being clinched when the space is not sufficient to permit the use of a regular holding-on tool.
DOLPHIN
A term applied to several piles that are bound together, situated either at the corner of a pier or out in the stream and used for docking and warping vessels. Also applied to single piles and bollards on piers that are used in docking and warping.
DONKEY ENGINE
A small gas, steam, or electric auxiliary engine set on the deck and used for lifting, etc.
DOOR, AIRTIGHT
A door so constructed that when closed it will prevent the passage of air under a small pressure. Used on air locks to boiler rooms under forced draft and in similar locations.
DOOR FRAME
The frame surrounding a door opening on which the door seats.
DOOR, JOINER
A light door fitted to staterooms and quarters where air and watertightness is not required. Made of wood, light metal, and metal-covered wood. Metal joiner doors with pressed panels are extensively used.
DOOR, WATERTIGHT
A door so constructed that, when closed, it will prevent water under pressure from passing through. A common type consists of a steel plate, around the edges of which a frame of angle bar is fitted, having a strip of rubber attached to the reverse side of the flange that is fastened to the door plate. The strip of rubber is compressed against the toe of the flange of an angle-iron door frame by dogs or clamps.
DOOR, WEATHERTIGHT
A term applied to outside doors on the upper decks which are designed to keep out the rain and spray.
DOUBLE BOTTOM
A term applied to the space between the inner and outer skins of a vessel called respectively the "inner bottom" and "shell", usually extending from bilge to bilge and for nearly the whole length of the vessel fore and aft, and subdivided into water or oil tight compartments. In some cases, and generally in warships, the inner bottom is carried above the bilges to a deck at or near the waterline. Where more than one inner skin is fitted, as is sometimes the case, the two spaces are known as the "lower bottom tank" or "void" and the "upper bottom tank". The outer skin is known as the "shell", the skin next to it as the "lower inner bottom", and the third skin as the "upper inner bottom".
DOUBLING PLATE
An extra plate secured to the original plating for additional strength or to compensate for an opening in the structure.
DOWEL
A pin of wood or metal inserted in the edge or face of two boards or pieces to secure them together.
DRAFT, DRAUGHT
The depth of the vessel below the waterline measured vertically to the lowest part of the hull, propellers, or other reference point. When measured to the lowest projecting portion of the vessel, it is called the "draft, extreme"; when measured at the bow, it is called "draft, forward"; and when measured at the stern, the "draft, aft"; the average of the draft, forward, and the draft, aft is the "draft, mean", and the mean draft when in full load condition is the "draft load".
DRAFT MARKS
The numbers which are placed on each side of a vessel near the bow and stern, and often also amidships, to indicate the distance from the number to the bottom of the keel or a fixed reference point. These numbers are six inches high, are spaced twelve inches bottom to bottom vertically, and are located as close to the bow and stern as possible.
DRAG
The designed excess of draft, aft, over that forward, measured from the designer's waterline. The drag is constant and should not be confused with trim.
DRIFT
When erecting the structure of a ship and rivet holes in the pieces to be connected are not concentric, the distance that they are out of line is called the drift. This should be corrected by reaming the holes, but common practice, which is prohibited in naval work, is to drive tapered pins, called "drift pins", into the unfair holes to force them into line.
DRIFT PIN
A conical-shaped pin gradually tapered from a blunt point to a diameter a little larger than the rivet holes in which it is to be used. The point is inserted in rivet holes that are not fair, and the other end is hammered until the holes are forced into line.
DRY DOCK, FLOATING
A hollowing floating structure of L- or U-shaped cross section, so designed that it may be submerged to permit floating a vessel into it, and that it may then raise the vessel and itself so that the deck of the dock and consequently the bottom of the vessel is above the level of the water. The bottom of a floating dry dock consists of one or more pontoons or rectangular-shaped vessels with high wing structure erected on one or both sides according to whether the section is to be L- or U-shaped. The deck of the pontoon is fitted with stationary keel blocks and movable bilge blocks which can be pulled under a vessel from the top of the wing structure. Pumps are fitted in the wings by which the dock can be quickly submerged or raised. Floating dry docks are used for repairing and painting the under-water portions of vessels and for docking a damaged vessel.
DRY DOCK, GRAVING
A basin excavated at a waterway and connected thereto by gates or a caisson which may be opened to let a vessel in or out and then closed and the water pumped out. The dock is fitted with stationary keel blocks and movable bilge blocks, which usually are fitted on rack tracks, allowing them to be pulled under a vessel before the water is pumped out. Graving docks are common in navy yards, and although more expensive to construct than floating dry docks, they are practically permanent and supply a more rigid foundation for supporting a ship. The gate of a graving dry dock is usually a caisson which is a complete vessel in itself, having a strong rectangular-shaped keel and end posts which bear against the bottom sill and side ledges at the entrance of the dry dock. The caisson is designed so that its draft may be adjusted by water ballast until it bears against the sill and ledges and is equipped with flood valves and power pumps to make this adjustment. When a ship is to be docked, sluice valves in the caisson or in the deck structure are opened until the water in the dock reaches the same level as the water outside. The caisson is then floated to one side, allowing a vessel to enter the dock. The caisson is then floated back to close the entrance, completely separating the basin from the waterway, and after the vessel is lined up over the keel blocks the water is pumped out of the dry dock.
DRY DOCK, RAILWAY
A railway dock consists of tracks built on an incline on a strong foundation and extending from a distance in-shore sufficient to allow docking a vessel of the maximum size for which the dock is built, to a distance underwater sufficient to allow the same vessel to enter the cradle. The cradle running on the tracks may be of wood or steel fitted with keel and bilge blocks and sufficiently weighted to keep it on the track when in the water. A hoisting engine with a winding drum or wild cat is fitted at the in-shore end of the railway which operates the cradle by a cable or chain. This type of dry dock is used for docking small ships. It is commonly called a "marine railway".
DUCTILITY
That property of a material which permits its being drawn out into a thread of wire.
DUNNAGE
Any material, such as blocks, boards, paper, burlap, etc., necessary for the safe stowage of stores and cargo; also used in reference to staging, etc., used by workmen during building or repair operations.
DUPLICATING PIPE
A piece of tubing, generally brass, used with paint to transfer rivet hole layout from template to plate. The end of the pipe is dipped in paint, and while still wet is pushed through each template hole, leaving an impression on the plate. Also called a "marker".
DUTCHMAN
A piece of wood or steel fitted into an opening to cover up poor joints or crevices caused by poor workmanship.


--E--

ECCENTRIC
A form of crank in which a circular disk set eccentrically upon a shaft forms both the crank web and the crank pin and converts circular to rectilinear motion. This rectilinear travel is usually short relative to the diameter of the shaft so that an ordinary form of crank is impractical.
EDGE
An abrupt border or margin, a bounding or dividing line, the part along the boundary.
EDGE, SIGHT
That edge of a strake of plating which laps outside another strake and is, therefore, in plain sight.
ELASTIC LIMIT
The limit of stress intensity within which a material will return to its original size and shape when the load is removed and hence not take a permanent set.
ELBOW-ELL
A pipe fitting that makes an angle between adjacent pipes, always 90 degrees unless another angle is stated.
ELECTRODE
Either a positive or negative pole or terminal in an electric circuit. See "polarity".
ENGINE ROOM
Space where the main engines of a ship are located.
ENTRANCE
The forward underwater portion of a vessel at or near the bow. The angle formed between the center line of the ship and the tangent to the designed waterline is called the angle of entrance.
EQUILIBRIUM, NEUTRAL
The state of equilibrium in which a vessel inclined from its original position of rest by an external force tends to maintain the inclined position assumed after that force has ceased to act.
EQUILIBRIUM, STABLE
The state of equilibrium in which a vessel inclined from its original position of rest by an external force tends to return to its original position after that force has ceased to act.
EQUILIBRIUM, UNSTABLE
The state of equilibrium in which a vessel inclined from its original position of rest by an external force tends to depart farther from the inclined position assumed after that force has ceased to act.
ERECTION
The process of hoisting into place and joining the various parts of a ship's hull, machinery, etc.
EVAPORATOR
An auxiliary for supplying fresh water, consisting of a salt water chamber heated by coils or nests of tubing through which live steam is circulated, converting the water into steam which is passed to a condenser or distiller to make up loss of boiler feed water or for other purposes requiring fresh water.
EVEN KEEL
When a boat rides on an even keel, its plane of flotation is either coincident with or parallel to the designed waterline.
EXPANSION JOINT
A term applied to a joint which permits linear movement to take up the expansion and contraction due to changing temperature or ship movement.
EXPANSION TANKS
Overflow tanks used to provide for expansion, overflow, and replenishment of oil in stowage or cargo tanks.
EXPANSION TRUNK
A trunk extending above a hold which is intended for stowage of liquid cargo. The surface of the cargo liquid is kept sufficiently high in the trunk to permit of expansion of the liquid without danger of excessive strain on the hull or of overflowing, and of contraction of the liquid without increase of the free surface and its accompanying effect upon the stability of the vessel.
EXTRA STRONG
The correct term or name applied to a certain class of pipe which is heavier than standard pipe and not as heavy as double extra strong pipe. Often, but less correctly, called extra heavy pipe.
EYE
A hole through the head of a needle, pin, bolt, etc. or a loop forming a hole or opening through which something is intended to pass, such as a hook, pin, shaft, or rope. A "worked eye" is one having its edges rounded off like a ring, while a "shackle eye" is drilled straight through, permitting an inserted bolt or pin to bear along its entire length.
EYE BOLT
A bolt having either a head looped to form a worked eye or a solid head with a hole drilled through it forming a shackle eye.
EYES
The forward end of the space below the upper deck of a ship which lies next abaft the stem where the sides of the ship approach very near to each other. The hawse pipes are usually run down through the eyes of a ship.


--F--

FABRICATE
To shape, assemble, and secure in place the component parts in order to form a complete whole. To manufacture.
FACE PLATE
A flat plate fitted perpendicular to the web and welded to the web plate, or welded or riveted to the flange or flanges of a frame, beam stiffener, or girder to balance the continuous plating attached to the opposite flange of the member.
FACTOR OF SAFETY
The ratio between either the ultimate strength of the elastic limit of the material and the allowed working stress. The former is usually referred to as the "nominal factor of safety" and the latter as the "real factor of safety". Elastic materials may have both nominal and real factors of safety, while for those materials having approximately the same values for ultimate strength and elastic limit, the distinction between real and nominal factors of safety is nonexistent.
FAIR CURVES
Curves which do not in any portions of their entire lengths show such changes of direction as to mark those portions as out of harmony in any respect with the curves as a whole or with the other portions of the curves.
FAIR or FAIR UP
To so draw the lines of a vessel that the defined surfaces will show no irregularities throughout their entire extent. To line up the frames of a vessel under construction to their proper position. Rivet holes are said to be fair when corresponding holes in the members joined are concentric.
FAIRLEADER
A fitting or device used to preserve or to change the direction of a rope, chain, or wire so that it will be delivered fairly or on a straight lead to a sheave or drum without the introduction of extensive friction. Fairleaders, or fairleads, are fixtures as distinguished from temporary block rigs.
FAIRWATER
A term applied to plating fitted to form a shape similar to a frustrum of a cone around the ends of shaft tubes and strut barrels to prevent an abrupt change in the streamlines. Also applied to any casting or plating fitted to the hull of a vessel for the purpose of preserving a smooth flow of water.
FAKE
To lay a rope or chain down in long bights side by side or in coils in regular order so that it will run out clear or can be easily and rapidly paid out. Also one complete circle of a coil of rope.
FALL
By common usage, the entire length of rope used in a tackle, although a strict adherence to the term would limit its application to that end to which the power is applied. The end secured to the block is called the standing part, the opposite end, the hauling part.
FANTAIL
The overhanging stern section of vessels which have round or elliptical after endings to uppermost decks and which extend well abaft the after perpendicular.
FASCIA
A strip of wood used on covering openings in joiner work.
FAST
A rope or chain used to moor a vessel to a wharf, designated in accordance with the end of the boat with which it is used as bow-fast or stern-fast. See "Painter".
FATHOM
A nautical unit of length used in measuring cordage, chains, depths, etc. The length varies in different countries, being six feet in the United States and in Great Britain.
FELLOES
Pieces of wood which form the rim of a wheel.
FENDER
The term applied to various devices fastened to or hung over the sides of a vessel to prevent rubbing or chafing against other vessels or piers. On small craft, as tug boats, fenders of timber faced with hardwood or flat steel plate, or of steel structure run fore and aft on the outside of the vessel above the waterline and are firmly secured to the hull. Wood spars, bundles of rope, woven cane, or rope-covered cork are hung over the sides by lines when permanent fenders are not fitted.
FID
A wood or metal bar used to support the weight of a topmast or a top-gallant mast when in position, being passed through a hole or mortise at its heel and resting on the trestle trees or other support. Also a hardwood tapering pin or tool, used by sailmakers and riggers to open the strands of a rope, eye, grommet, etc., A "hand fid" is rounded at the ends, a "standing or cringle fid" is larger than a hand fid and has a flat base.
FIDLEY
Framework built around a weather-deck hatch through which the smoke pipe passes.
FIDLEY DECK
A partially raised deck over the engine and boiler rooms, usually around the smokestack.
FIDLEY HATCH
Hatch around smokestack and uptake.
FIFE RAIL; PIN RAIL
A term applied to a rail worked around a mast and fitted with holes to take belaying pins for securing the running gears.
FILLET
A term applied to the metal filling in the bosom or concave corners where abrupt changes in direction occur in the surface of a casting, forging, or weldment.
FIN
A projecting keel. A thin plane of metal projecting from hull, etc.
FIRE CONTROL
Pertaining to the direction, the control, and the firing of the vessel's batteries.
FITTINGS, PIPE
A term applied to the connections and outlets, with the exception of valves and couplings, that are attached to pipes.
FIXED LIGHT
A thick glass, usually circular in shape, fitted in a frame fixed in an opening in a ship's side, deck house, or bulkhead to provide access for light. The fixed light is not hinged. Often incorrectly called a dead light.
FLAGSTAFF
Flag pole, usually at the stern of a ship; carries the ensign.
FLAM
A term used to express the same meaning as flare, but more properly used to denote the maximum curl or roll given to the flare at the upper part, just below the weather deck.
FLANGE
The turned edge of a plate or girder which acts to resist bending. The turned edge of a plate or shape for tying in intersecting structural members. A casting or forging attached to or worked integral with a pipe to form a disk, normal to the axis of an exterior to the pipe, for connecting lengths of pipe,
FLARE
The spreading out from a central vertical plane of the body of a ship with increasing rapidity as the section rises from the water line to the rail. Also a night distress signal.
FLAT
A small partial deck, built without camber.
FLOATING POWER
The sum of the utilized and the reserve buoyancy of a vessel, or the displacement of the completely watertight portion of the vessel when fully submerged. The utilized buoyancy is that buoyancy required to support the weight of the vessel.
FLOODABLE LENGTH
The length of a vessel which may be flooded without sinking her below her safety or margin line. The value of the floodable length of a given vessel varies from point to point throughout her length due to change in form. Similarly at a given point it varies from time to time, depending upon the condition of loading and the permeability of the cargo.
FLOOR
A plate used vertically in the bottom of a ship running athwartship from bilge to bilge usually on every frame to deepen it. In wood ships, the lowest frame timber or the one crossing the keel is called the floor.
FLUKES
The palms or broad holding portions at the arm extremities of an anchor, which penetrate the ground.
FLUX
A fusable material or gas used to dissolve or prevent the formation of oxides, nitrides, or other undesirable inclusions formed in welding and brazing.
FOOTINGS
Bottom boards of walking flats attached to the inside of the frames of small boats where deep floors are not fitted.
FORE
A term used in indicating portions or that part of a ship at or adjacent to the bow. Also applied to that portion and parts of the ship lying between the midship section and stem; as, fore body, fore hold, and foremast.
FORE AND AFT
Lengthwise of a ship.
FORECASTLE
A short structure at the forward end of a vessel formed by carrying up the ship's shell plating a deck height above the level of her uppermost complete deck and fitting a deck over the length of this structure. The name applied to the crew's quarters on a merchant ship when they are in the fore part of the vessel.
FOREFOOT
The lower end of a vessel's stem which is stepped on the keel. That point in the forward end of the keel about which the boat pivots in an endwise launching.
FOREHOOK
See "breast hook".
FORE PEAK
The extreme forward end of the vessel below decks. The forward trimming tank.
FORGING
A mass of metal worked to a special shape by hammering, bending, or pressing while hot.
FORK BEAM
A half beam to support a deck here hatchways occur.
FORWARD
In the direction of the stem.
FORWARD PERPENDICULAR
A line perpendicular to the base line and intersecting the forward side of the stem at the designed waterline.
FOUL
A term applied to the underwater portion of the outside of a vessel's shell when it is more or less covered with sea growth or foreign matter. It has been found that even an oily film over the vessel's bottom will retard the speed, while sea growth will reduce a vessel's propulsive efficiency to a large extent. Also, obstructed or impeded by an interference, etc.
FOUND
To fit and bed firmly. Also, equipped.
FOUNDER
To sink as the result of entrance of water.
FRAME
A term generally used to designate one of the transverse ribs that make up the skeleton of a ship. The frames act as stiffeners, holding the outside plating in shape and maintaining the transverse form of the ship.
FRAME, BOSS
A frame that is bent to fit around the boss in the way of a stern tube or shaft.
FRAME LINES
Molded lines of a vessel as laid out on the mold loft floor for each frame, showing the form and position of the frames.
FRAME SPACING
The fore-and-aft distances between frames, heel to heel.
FREEBOARD
The vertical distance from the waterline to the top of the weather deck at side.
FREEING PORTS
Holes in the lower portion of a bulwark, which allow deck wash to drain off into the sea. Some freeing ports have swinging gates which allow water to drain off but which are automatically closed by sea-water pressure.
FURNACED PLATE
A plate that requires heating in order to shape it as required.
FURRINGS
Strips of timber, metal, or boards fastened to frames, joists, etc., in order to bring their faces to the required shape or level, for attachment of sheathing, ceiling, floor, etc.
FUTTOCKS
The pieces of timber of which a frame in a wood ship is composed. Starting at the keel they are called the first futtock, second futtock, third futtock, and so on.


--G--

GAFF
A spar to which the top of a fore-and-aft sail is attached. It is usually fitted with a jaw at the mast end to clasp the mast.
GAGE, DRAFT
An installation comprising a graduated glass tube, connected at the bottom end with the sea and with the top end open to the air, on which the draft of the vessel is shown by the level of water in the tube.
GALLEY
The space on a vessel in which the food is prepared and cooked.
GALVANIZING
The process of coating one metal with another, ordinarily applied to the coating of iron or steel with zinc. The chief purpose of galvanizing is to prevent corrosion.
GANGBOARD, GANGPLANK
A term applied to boards or a movable platform used in transferring passengers or cargo from a vessel to or from a dock.
GANGWAY
The term applied to a place of exit from a vessel. Gangways are fitted in the sides of a vessel in the shape of ports requiring means of closure or may be movable portions of bulwarks or railing on the weather decks.
GANTLINE or GIRTLINE
A rope reeving through a single block aloft and used for hoisting or lowering rigging, drying clothing and hammocks, etc.
GARBOARD
The strakes of outside plating next to the keel. These strakes act in conjunction with the keel and are usually thicker than the other bottom strakes.
GASKETS
Packing materials, by which air, water, oil, or steam tightness is secured in such places as on doors, hatches, steam cylinders, manhole covers, or in valves, between the flanges of pipes, etc. Such materials as rubber, canvas, asbestos, paper, sheet lead and copper, soft iron, and commercial products are extensively used.
GEAR
A comprehensive term in general use on shipboard signifying the total of all implements, apparatus, mechanism, machinery, etc., appertaining to and employed in the performance of any given operation, as "cleaning gear," "steering gear," "anchor gear," etc.
GEARING
A term applied to wheels provided with teeth that mesh, engage, or gear with similar teeth on other wheels in such manner that motion given one wheel will be imparted to the other.
GIB
A metal fitting to hold a member in place or press two members together, to afford a wearing or bearing surface, or to provide a means of taking up wear.
GIMBALS
A device by which a ship's compass, chronometer, etc., is suspended so as to remain in a constant horizontal position irrespective of the rolling or pitching of the vessel. It consists of two concentric brass hoops or rings whose diameters are pivoted at right angles to each other on knife-edge bearings.
GIRDERS
On ships this term is used to define a structural member which provides support for more closely spaced members, such as beams, frames, stiffeners, etc., which are at right angles to it and which either rest upon it or are attached to its web. It may be longitudinal or transverse, continuous or intercoastal, and is usually supported by bulkheads and stanchions. The term is also used to designate the longitudinal members in the double bottom.
GIRTH
The distance measured on any frame line, from the intersection of the upper deck with the side, around the body of the vessel to the corresponding point on the opposite side.
GOOSENECK
A swivelling fitting on the keel or mast end of a boom for connecting the boom to the mast. Also called a Pacific iron.
GRAB, HAND
A metal bar fastened to a bulkhead, house side, or elsewhere, to provide means of steadying a person when the ship rolls or pitches.
GRAPNEL
An implement having from four to six hooks or prongs, usually four, arranged in a circular manner around one end of a shank having a ring at its other end. Used as an anchor for small boats, for recovering small articles dropped overboard, to hook on to lines, and for similar purposes. Also known as a Grappling Hook.
GRATINGS
A structure of wood or metal bars so arranged as to give a support or footing over an opening, while still providing spaces between the members for the passage of light and the circulation of air.
GRIPE
The sharp forward end of the dished keel on which the stem is fixed. A curved piece of timber joining the forward end of the keel and the lower end of the cutwater. A lashing, chain, or the like, used to secure small boats in the chocks and in sea position in the davits.
GROMMET
A wreath or ring of rope. Fibre, usually soaked in red lead or some such substance, and used under the heads and nuts of bolts to secure tightness. A worked eye in canvas.
GROUND TACKLE
A general term for all anchors, cables, ropes, etc., used in the operation of mooring and unmooring a ship.
GROUNDWAYS
Timbers fixed to the ground and extending fore and aft under the hull on each side of the keel, to form a broad surface track on which the ship is end-launched. "Groundways" for a side launching embody similar basic features.
GUDGEONS
Lugs cast or forged on the stern post for the purpose of hanging and hinging the rudder. Each is bored to form a bearing for a rudder pintle and is usually bushed with lignum vitae or white bearing metal.
GUNWALE
A term applied to the line where a weather deck stringer intersects the shell. The upper edge of the side of an open boat.
GUNWALE BAR
A term applied to the bar connecting a stringer plate on a weather deck to the sheer strake.
GUSSET PLATE
A bracket plate lying in a horizontal, or nearly horizontal, plane. The term is often applied to bracket plates.
GUTTER EDGE
A bar laid across a hatchway to support the hatch cover.
GUYS
Wire or hemp ropes or chains to support booms, davits, etc., laterally, employed in pairs. Guys to booms that carry sails are also known as backropes.
GYPSY
A small auxiliary drum usually fitted on one or both ends of a winch or windlass. The usual method of hauling in or slacking off on ropes with the aid of a gypsy is to take one or more turns with the bight of the rope around the drum and to take in or pay out the slack of the free end.


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HALF-BREADTH PLAN
A plan or top view of one-half of a ship divided by the middle vertical plane. It shows the waterlines, cross section lines, bow and buttock lines, and diagonal lines of the ship's form projected on the horizontal base plane of the ship.
HALF MODEL
A model of one-half of a ship divided along the middle vertical plane.
HALYARDS
Light lines used in hoisting signals, flags, etc. Also applied to the ropes used in hoisting gaffs, sails, or yards.
HAMPER, TOP HAMPER
Articles of outfit, especially spars, rigging, etc., above the deck, which, while ordinarily indispensable, may become in certain emergencies both a source of danger and an inconvenience.
HARD PATCH
A plate riveted over another plate to cover a hole or break.
HARPINGS; HARPINS
The fore parts of the wales of a vessel which encompass her bows and are fastened to the stem, thickened to withstand plunging. The ribbands bent around a vessel under construction to which the cant frames are temporarily secured to hold them in their proper position.
HATCH, HATCHWAY
An opening in a deck through which cargo may be handled, machinery or boilers installed or removed, and access obtained to the decks and holds below. Hatch is properly a cover to a hatchway but is often used as a synonym for hatchway.
HATCH BAR
A term applied to flat bars used for securing and locking hatch covers. A bar over the hatch for rigging a tackle.
HATCH BATTENS
A term applied to flat bars used to fasten and make tight the edges of the tarpaulins that are placed over hatches. The batten and the edge of the tarpaulin are wedged tightly in closely-spaced cleats.
HATCH BEAMS
A term applied to the portable beams fitted to the coamings for the purpose of supporting the hatch covers.
HATCH, BOOBY
An access hatchway leading from the weather deck to the quarters. A small companion which is readily removable in one piece. A wooden, hoodlike covering for a hatchway, fitted with a sliding top.
HATCH CARRIER
The supports which are attached to the inside of the coaming to take the ends of the hatch beams.
HATCH CLEATS
A term applied to the clips attached to the outside of the hatch coaming for the purpose of holding the hatch battens and wedges which fasten the edges of the tarpaulin covers.
HATCH COVERS or HATCHES
Covers for closing the hatchway, in cargo ships usually made of wood planks in sections that can be handled by the crew. In naval ship, steel hatch covers are used. The wood cover is made tight against rain and the sea by stretching one or more tarpaulins over them, secured at the edges by the hatch battens.
HATCH RESTS
A term applied to the shelf fitted inside and just below the top of the coaming for the purpose of supporting the hatch covers.
HATCHWAY TRUNK
A term applied to the space between a lower deck hatchway and the hatchway or hatchways immediately above it when enclosed by a casing. A trunk may be either watertight or nonwatertight.
HAWSE
The hawse hole; also the part of a ship's bow in which the hawse holes for the anchor chains are located.
HAWSE BAG
A conical-shaped canvas bag, stuffed with sawdust, oakum, or similar material, and fitted with a lanyard at apex and base, used for closing the hawse pipes around the chain to prevent shipping water through the pipes; also called a "jackass", "hawse plug", or "hawse block".
HAWSE BOLSTER
A timber or metal bossing at the ends of a hawse pipe to ease the cable over the edges and to take the wear.
HAWSE HOLE
A hole in the bow through which a cable or chain passes.
HAWSE PIPES
Tubes leading the anchor chain from the deck on which the windlass is located down and forward through the vessel's bow plating.
HAWSER
A large rope or a cable used in warping, towing, and mooring.
HEAD LEDGE
A term applied to the forward or after end coaming of a hatch, more frequently used in connection with wood coamings.
HEAD OF A SHIP
The fore end of a ship which was formerly fitted up for the accommodation of the crew. A term applied to a toilet on board of a ship. A ship is trimmed by the head when drawing more water forward and less aft than contemplated in her design.
HEEL
The convex intersecting point or corner of the web and flange of a bar. The inclination of a ship to one side, caused by wind or wave action or by shifting weights on board.
HEEL PIECE, HEEL BAR
A bar that serves as a connecting piece between two bars which butt end-to-end. The flange of the heel bar is reversed from those of the bars it connects.
HELM
The term applied to the tiller, wheel, or steering gear, and also the rudder.
HOG
A scrub broom for scraping a ship's bottom under water.
HOG FRAME
A fore-and-aft frame, forming a truss for the main frames of a vessel to prevent bending.
HOGGING
A term applied to the distortion of a vessel's hull when her ends drop below their normal position relative to her midship portion.
HOG SHEER
The sheer curve of the deck on a vessel, constructed so that the middle is higher than the ends.
HOIST
To raise or elevate by manpower or by the employment of mechanical appliances; any device employed for lifting weights.
HOLD
The space or compartment between the lowermost deck and the bottom of the ship, or top of the inner bottom if one is fitted. The space below decks allotted for the stowage of cargo.
HOLD BEAMS
Beams in a hold similar to deck beams but having no decking or planking on them.
HOME
Close up; snugly in place; as, to drive home a bolt.
HOOD
A shelter over a companionway, scuttle, etc. It is generally built of canvas spread over an iron frame. It may also be constructed of light metal plating.
HOODS
A term applied to those plates placed at the extreme forward or after ends of a ship.
HOODING END
The endmost plate of a complete strake. The hooding-ends fit into the stem or stern post.
HORNING
Setting the frames of a vessel square to the keel after the proper inclination to the vertical due to the declivity of the keel has been given.
HORSE TIMBER
The after longitudinal strength member (often called counter timber) fastening the shaft log or keel and the transom knee together. A small boat term.
HORSING
(In naval architecture). Calking planking with oakum with a large maul or beetle and wedge-shaped iron.
HOUSING
A term applied to an inclosure partially or wholly worked around fittings or equipment. That portion of the mast below the surface of the weather deck. Applied to topmasts, that portion overlapping the mast below.
HULL
The framework of a vessel, together with all decks, deck houses, and the inside and outside plating or planking, but exclusive of masts, yards, rigging, and all outfit or equipment.

25 August 2003