Abaft: Toward the stern of a ship;
back; behind; back of; further aft than.
Aboard: On or in a ship.
Abreast: Side by side.
Accommodation Ladder: Stairs slung at
the gangway, leading down, the vessel's side to a point near the water,
for ship access from small boats.
Aft: Near the stern; toward the stern.
After Body: That portion of a ship's
body aft of the midship section.
After Frames: Frames aft of amidships,
or frames near the stern of the ship.
After Peak: The aftermost tank or
compartment forward of the stern post.
After Perpendicular: A line
perpendicular to the base line intersecting the after-edge of the stern
post at the designed water line. On submarines or ships having a similar
stern, it is a vertical line passing through the point where the
designed water line intersects the stern of the ship.
Air Port: An opening in the side or
deck house of a vessel, usually round in shape and fitted with a hinged
frame in which a thick glass is secured.
Aloft: In the upper rigging; above the
Amidships: In the vicinity of the
middle portion of a vessel as distinguished from her ends. The term is
used to convey the idea of general locality but not that of definite
Anchor: A heavy iron or steel
implement attached to a vessel by means of a rope or chain cable for
holding it at rest in the water. When an anchor is lowered to the
bottom, the drag on the cable causes one or more of the prongs, called
flukes, to sink into the ground which provides holding power.
Anchor, Bower: The large anchors
carried in the bow of a vessel. Three are usually carried, two (the main
bowers) in the hawsepipes, or on bill boards, and a third (spare) lashed
on deck or elsewhere about the vessel for use ,in the event either of
the main bowers is lost. The weight varies with the size and service of
Anchor, Kedge: A small anchor used for
warping or kedging. It is usually planted from a small boat, the vessel
being hauled up toward it. The weight varies, being usually from 900 to
Anchor, Sea: This is not a true anchor
as it does not sink to the bottom. It is a conical shaped canvas bag
required by the Bureau of Marine Inspection to be carried in each
lifeboat. When placed overboard it serves a double purpose in keeping
the boat head on into the sea and in spreading a vegetable or animal oil
from a container placed inside the bag. It is sometimes called an oil
Anchor, Stream: An anchor weighing
from about one-fourth to one-third the weight of the main bowers and
used when mooring in a narrow channel or harbor to prevent the vessel's
stern from swinging with the current or the tide.
Angle: Same as angle bar.
Angle Bar: A bar of angle-shaped
section used as a stiffener and for attachment of one plate or shape to
Angle Bulb: A structural shape having
a bulb on one flange of the, angle, used as a frame, beam, or stiffener.
Angle Collar: A collar or band made of
one or more pieces of angle bar and fitted tightly around a pipe, trunk,
frame, longitudinal, or stiffener intersecting or projecting through a
bulkhead or deck for the purposes of making a watertight or oiltight
joint. See Stapling.
Appendages: Relatively small portions
of a vessel extending beyond its main outline as shown by transverse and
water plane sections, including such items as shafting, struts, bossings,
docking and bilge keels, propellers, rudder, and any, other feature,
extraneous to the hull and generally immersed.
Area of Sections: The area of any
cross section of the immersed portion of a vessel, the cross section
being taken at right angles to the fore and aft centerline of the
Astern: Signifying position, in the
rear of or abaft the stern; as regards motion, the opposite of going
Athwart: Across, from side to side,
transverse, across the line of a vessel's course.
Athwartship: Reaching across a vessel,
from side to side.
Auxiliaries: Various winches, pumps,
motors, engines, etc., required on a ship, as distinguished from main
propulsive machinery (boilers and engines on a steam installation).
Awning: A roof like canopy of canvas
suspended above a vessel's decks, bridges, etc., for protection against
sun and weather.
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Back Stay: Stays which extend from all
mast levels, except the lower, to the ship's side at some distance abaft
the mast. They serve as additional supports to prevent the masts going
forward. And also contribute to the lateral support, thereby assisting
Balanced Rudder: A rudder with its
axis between the forward and after edge.
Ballast: Any weight carried solely for
the purpose of making the vessel more seaworthy. Ballast may be either
portable or fixed, depending upon the condition of the ship. Fixed or
permanent ballast in the form of sand, concrete, lead, scrap, or pig
iron is usually fitted to overcome an inherent defect in stability or
trim due to faulty design or changed character of service. Portable
ballast, usually in the form of water pumped into or out of the bottom,
peak, or wing ballast tanks, is utilized to overcome a temporary defect
in stability or trim due to faulty loading, damage, etc., and to
Ballast Tanks: Tanks provided in
various parts of a ship for introduction of water ballast when necessary
to add weight to produce a change in trim or in stability of the ship,
and for submerging submarines.
Ballast Water: Sea water, confined to
double bottom tanks, peak tanks, and other designated compartments, for
use in obtaining satisfactory draft, trim, or stability.
Ballasted Condition: A condition of
loading in which it becomes necessary to fill all or part of the ballast
tanks in order to secure proper immersion, stability, and steering
qualities brought about by consumption of fuel, stores, and water or
lack of part or all of the designed cargo.
Barge: A craft of full body and heavy
construction designed for the carriage of cargo but having no machinery
Batten: Long, thin, strips of wood,
steel, or plastic, usually of uniform rectangular section used in the
drafting room and mold loft to lay down the lines of a vessel, but
sometimes thinned down in the middle or at the ends to take sharp
curves. A strip of wood or steel used in securing tarpaulins in place.
To secure by means of battens, as to "batten down a hatch."
Battens, Cargo: A term applied to the
wood planks or steel shapes that are fitted to the inside of the frames
in a hold to keep the cargo away from the shell plating; the strips of
wood or steel used to prevent shifting of cargo.
Beam: The extreme width of a ship.
Also an Athwartship or longitudinal member of the ship's structure
supporting the deck.
Beam Knee: A bracket between a frame
or stiffener and the end of a beam; a beam arm.
Beam Line: A line showing the points
of intersection between the top edge of the beam and the molded frame
line, also called it molded deck line.”
Beam, Transom: A strong deck beam
situated in the after end of the vessel connected at each end to the
transom frame. The cant beams which support the deck plating in the
overhang of the stern are attached to and radiate from it.
Bearer: A term applied to foundations,
particularly those having vertical web plates as principal members. The
vertical web plates of foundations are also called bearers.
Bearing: A block on or in which a
journal rotates; a bearing block.
Bell Mouthed: A term used to signify
the open end of a pipe when it expands or spreads out with an increasing
Below: Underneath the surface of the
water. Underneath a deck or decks.
Bending Rolls: A large machine used to
give curvature to plates by passage in contact with three rolls.
Bending Slab: Heavy cast-iron blocks
with square or round holes for “dogging down” arranged to form a large
solid floor on which frames and structural members are bent and formed.
Berth: A term applied to a bed or a
place to sleep. Berths, as a rule, are, permanently built into the
structure of the staterooms or compartments. They are constructed singly
and one above the other. Also, a place for a ship.
Between Decks: The space between any
two, not necessarily adjacent decks. Frequently expressed as “'tween
Bevel: A term for a plane having any
other angle than 90 degrees to a given reference plane.
Bevel, Closed: A term applied where
one flange of a bar is bent to form an acute angle with the other
Bevel, Open: A term applied where one
flange of a bar is bent to form an obtuse angle with the other flange.
Frame bars in the bow and the stern of a vessel are given an open bevel
to permit access for riveting to shell and to keep the standing flange
parallel to the deck beams.
Bight: A loop or bend in a rope;
strictly, any part between the two ends may be termed the bight.
Bilge: The rounded portion of a
vessel's shell which connects the bottom with side. To open a vessel's
lower body to the sea.
Bilge Plates: The curved shell plates
that fit the bilge.
Bilges: The lowest portion of a ship
inside the hull, considering the inner bottom where fitted as the bottom
Bill Board: An inclined platform,
fitted at the intersection of the forward weather deck and the shell,
for stowing an anchor. It may be fitted with a tripping device for
dropping the anchor overboard. Seldom fitted since the stockless anchor
has come into general use.
Bitter End: The inboard end of a
vessel's anchor chain which is made fast in the chain locker.
Bitts: A term applied to short metal
or wood columns extending up from a base plate secured to a deck or
bulwark rail or placed on a pier and to timbers extended up through and
a short distance above a deck for the purpose of securing and belaying
ropes, hawsers, cables', etc. Also called bollards.
Bitumastic: A black tarlike'
composition largely of bitumen or asphalt and containing such other
ingredients as rosin, Portland cement, slaked lime, petroleum, etc. It
is used as a protective coating in ballast and trimming tanks, chain
lockers, shaft alleys, etc.
Bleeder: A small cock, valve, or plug
to drain off small quantities of fluids from a container or system.
Blind Pulley: A circular block of hard
wood with rounded edges perforated by several holes having grooves
running from them to one side of the block. One of these blocks is
secured to an end of a part of the standing rigging, as a shroud, and
another to the chain plate or to some part of the ship and the two are
connected to one another by a lashing passing through the holes.
Commonly called "dead eyes."
Block: The name given to a pulley or
sheave, or a system of pulleys or sheaves, mounted in a frame or shell
and used for moving objects by means of ropes run over the pulleys or
sheaves. The prefixes single, double, triple, etc., indicate the number
of pulleys or sheaves in the block. The five principal parts of a block
are (a) the shell, or outside frame, (b) the sheave, on which the rope
runs, (c) the pin, on which the sheave turns, (d) the strap, by which
the hook is held in position and which provides bearing for the pin, and
(e) the hook, which may be open, sister, or shackle and fixed or swivel.
The opening between the top of the sheave and the shell is called the
swallow, that between the bottom of the sheave and the shell is called
the breech, and, the device attached to the bottom of the block opposite
the hook for securing the standing part of the fall to the block is
called the Becket.
Block, Cheek: A half shell block with
a single sheave bolted to a mast or other object which serves as the
other half shell or cheek. Usually used in connection with halyards.
Block, Fiddle: A block having two
sheaves of different diameters, placed in the same plane one above the
Block, Snatch: A single sheave block
having one side of the frame hinged so that it can be opened to allow
the bight of a rope to be placed on the sheave; thus avoiding the
necessity of threading the end of the rope through the swallow of the
block. Usually employed as a fair lead around obstructions.
Blower: A mechanical device used to
supply air under low pressure for artificial ventilation and forced
draft, usually of the centrifugal type.
Boarding: The act of going on board a
Bobstays: The chains or ropes attached
underneath the outer end of the bowsprit and led aft to the sten to
prevent the bowsprit from jumping up. Where two are fitted they are
called the inner and the cap bobstays; when three are fitted they are
called the inner, the middle, and the cap bobstays.
Body Plan: A plan consisting of two
half transverse elevations or end views of a ship, both having a common
vertical center line, so that the right-hand side represents the ship as
seen from ahead, and the left-hand side as seen from astern. On the body
plan appear the forms of the various cross sections, the curvature of
the deck lines at the side, and the projections, as straight lines of
the water lines, the bow and buttock lines, and the diagonal lines.
Boiler: Any vessel, container, or
receptacle that is capable of generating steam by the internal or
external application of heat. The two general classes are fire tube and
Boiler Casing: Walls fanning a trunk
leading from the boiler room to the boiler hatch, which protect the
different deck spaces from the heat of the boiler room, etc.
Boiler Room: A compartment in the
hold, in the middle or after section of a vessel where the boilers are
BoIIards: See "bitts."
Bolster Plate: A piece of plate
adjoining the hawse hole, to prevent the chafing of the hawser against
the cheek of a ship's bow. A plate for support like a pillow or cushion.
Bolt: A metal rod used as a fastening.
With few exceptions, such as drift bolts, a head or shoulder is made on
one end and a screw thread to carry a nut is cut on, the other.
Bolting Up: Securing by means of bolts
and nuts parts of a structure in proper position for permanent
attachment by riveting or welding. A workman employed on this work is
called a "bolter up."
Bonjean Curves: Curves of areas of
transverse sections of a ship. The curves of the moments of these areas
above the base line are sometimes included.
Booby Hatch: An access hatch from a
weather deck protected by a hood from sea and weather. The hood is often
fitted with a sliding cover to facilitate access.
Boom: A term applied to a spar used in
handling cargo, or to which the lower edge of, a fore-and -aft sail is
Boom Table: A structure built up
around a mast from the deck to support the heel bearings of booms and to
provide proper working clearances when a number of booms are installed
on or around one mast.
Boot topping: An outside area on a
vessel's hull from bow to stern between certain waterlines to which
special air, water, and grease-resisting paint is applied; also the
paint applied to such areas.
Bosom: The inside of an angle bar.
Bosom Bar: An angle fitted inside
Bosom Plate: A plate bar or angle
fitted in the bosoms of two angle bars to connect the ends of the two
angles as if by a butt strap.
Boss: The curved, swelling portion of
the ship's underwater hull around the propeller shaft .
Boss Plate: The plate that covers the
Bottom: That portion of a vessel's
shell between the keel and the lower turn of the bilge.
Bottom, Outer: A term applied to the
bottom shell plating in a double bottom ship.
Bottom Plating: That part of the shell
plating which is below the water line. More specifically, the immersed
shell plating from bilge to bilge.
Bow: The forward end of the ship. The
sides of the vessel at and for some distance abaft the stem, designated
as the right-hand or starboard bow and the left-hand, or port-bow.
Bow Lines: Curves representing
vertical sections parallel to the central longitudinal vertical plane of
the bow end of a ship. Similar curves in the aft part of a hull are
called buttock lines. Also, a rope leading from the vessel's bow to
another vessel or to a wharf for the purpose of hauling her ahead or for
Bowsprit: A spar projecting forward
over the bow for the purpose of holding the lower ends of the head
Brace: A rope attached to the yard
arm, used to alter the position of the yard arm in a horizontal plane.
The operation is known as trimming the sail.
Bracket: A steel plate, commonly of
triangular shape with a reinforcing flange, on its free edge, used to
connect two parts such as deck beam to frame, frame to ,margin plate,
'etc.; also used to stiffen or tie beam angles to bulkheads, frames to
Breadth, Extreme: The maximum breadth
measured over plating or planking, including beading or fenders.
Breadth, Molded: The greatest breadth
of the vessel measured from heel of frame on one side to heel of frame
on other side.
Breadth, Registered: Measured at
amidships at its greatest breadth to outside of plating.
Break of Forecastle or Poop: The point
at which the partial decks known as the forecastle and poop are
Breakwater: A term applied to plates
or timbers fitted on a forward weather deck to form a V -shaped shield
against water that is shipped over the bow.
Breast Hook: A triangular-shaped plate
fitted parallel to and between decks or side stringers in the bow for
the purpose of rigidly fastening together the peak frames, stem, and
outside plating; also used, in conjunction with the above duties, to
fasten the ends of side stringers firmly together.
Bridge: A high transverse platform,
often fanning the top of a bridge house, extending from side to side of
the ship, and from which a good view of the weather deck may be had. An
enclosed space called the pilot house is erected on the bridge in which
are installed the navigating instruments, such as the compass and
binnacle, the control for the steering apparatus, and the signals to the
engine room. While the pilot house is generally extended to include a
chartroom and sometimes staterooms, a clear passageway should be left
around it. As the operation of the ship is directed from the bridge or
flying bridge above it, there should also be a clear, open passage from
one side of the vessel to the other. The term is also applied to the
narrow walkways, called connecting bridges, which connect the bridge
deck with the poop and forecastle decks. This type of bridge is usually
found on tankers and is desirable whenever bulwarks are not fitted.
Bridge House: A term applied to an
erection or superstructure fitted about amidships on the upper deck of a
Bridge, Navigating, or Flying: The
uppermost platform erected at the level of the top of the pilot house. I
t generally consists of a narrow walkway supported by stanchions,
running from one side of the ship to the other and the space over the
top of the pilot house. A duplicate set of navigating instruments and
controls for the steering gear and engine room signals are installed on
the flying bridge so that the ship may be navigated in good weather from
this platform. Awnings erected on stanchions and weather cloths fitted
to the railing give protection against sun and wind.
Broken Backed: Said of a vessel when,
owing to insufficient longitudinal strength, grounding, or other
accident, her sheer is reduced or lost, thereby producing a drooping
effect at both ends.
Brow: A gangplank usually fitted with
rollers at the end resting on the wharf to allow for the movement of the
vessel with the tide. See watershed.
Buckle: A distortion, such as a bulge;
to become distorted; to bend out of its own plane.
Buckler: Generally, but not
exclusively, applied to various devices used to prevent water from
entering hawse and chain pipes, etc.
Buckling: The departure of a plate,
shape, or stanchion from its designed plane or axis when subjected to
Building Slip: An inclined launching
berth where the ship is built.
Bulkhead: A term applied to anyone of
the partition walls which subdivide the interior of a ship into
compartments or rooms. The various types of bulkheads are distinguished
by the addition of a word or words, explaining the location, use, kind
of material or method of fabrication, such as fore peak, longitudinal,
transverse, watertight, wire mesh, etc. Bulkheads which contribute to
the strength and seaworthiness of a vessel are called strength
bulkheads, those which are essential to the watertight subdivision are
watertight or oiltight bulkheads.
Bulkhead, After Peak: A term applied
to the first transverse bulkhead forward of the stern post. This
bulkhead forms the forward boundary of the afterpeak tank and should be
Bulkhead, Collision: The foremost
transverse watertight bulkhead in a ship which extends from the bottom
of the hold to the freeboard deck. It is designed to keep water out of
the forward hold in case of collision damage. Usually, this is the fore
peak bulkhead at the after end of the fore peak tank.
Bulkhead, Joiner: Wood or light metal
bulkheads serving to bound staterooms, offices, etc., and not
contributing to the ship's strength.
Bulkhead Stiffener: Members attached
to the plating of a bulkhead for the purpose of holding it in a plane
when pressure is applied to one side. The stiffener is generally
vertical, but horizontal stiffeners are used and both are found on same
bulkheads. The most efficient stiffener is a T section; flat bars,
angles, channels, zees, H and I sections are commonly used.
Bulkhead, Swash: A strongly built,
nontight bulkhead placed in oil or water tanks to slow down the motion
of the fluid set up by the motion of the ship.
Bulkhead, Wire Mesh: A partition or
enclosure bulkhead, used largely in store rooms, shops, etc., made of
wire mesh panels.
Bulldozer - A machine, usually
hydraulic or electric, for bending bars, shapes or plates while cold.
Bulwark: A term applied to the strake
of shell plating or the side planking above a weather deck. It helps to
keep the deck dry and also serves as a guard against losing deck cargo
or men overboard. Where bulwarks are fitted, it is customary to provide
openings in them which are called freeing ports, to allow the water that
breaks over to clear itself.
Bulwark Stay: A brace extending from
the deck to a point near the top of the bulwark, to keep it rigid.
Bumped: A term applied to a plate
which has been pressed or otherwise formed to a concave or convex shape.
Used for heads of tanks, boilers, etc.
Bunk: A built-in berth or bed.
Bunker: A compartment used for the
stowage of coal or oil fuel.
Buoyancy: Ability to float; the
supporting effort exerted by a liquid (usually water) upon the surface
of body, wholly or partially immersed in it.
Buoyancy, Reserve: The floating or
buoyant power of the un submerged portion of the hull of a vessel.
Usually referred to a specific condition of loading.
Butt: That end or edge of a plate or
timber where it comes squarely against another piece; or, the joint thus
Buttock: The rounded-in overhanging
part on each side of the stern in front of the rudder, merging
underneath in the run.
Buttock Lines: The curves shown by
taking vertical longitudinal sections of the after part of a ship's hull
parallel to the ship's keel. Similar curves in forward part of hull are
Butt Strap: A term applied to a strip of plate serving as a connecting
strap between the butted ends of the plating. The strap connections at
the edges are called seam straps.
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Cabin: The interior of a deck house,
usually the space set aside for the use of officers and
Caisson: A watertight structure used
for raising sunken vessels by means of compressed air. Also the floating
gate to close the entrance to a dry dock.
Calking: The operation of jamming
material into the contact area to make a joint watertight or oiltight.
Camber, Round of Beam: The weather
decks of ships are rounded up or arched in an Athwartship direction for
the purpose of draining any water that may fall on them to the sides of
the ship where it can be led overboard through scuppers. The arching or
rounding up is called the camber or round of the beam and is expressed
in inches in connection with the greatest molded breadth of the ship in
feet, thus, "the main deck has a camber of 10 inches in 40 feet." In is
measured at the center line of the ship at the greatest molded breadth
and is the distance from the chord to the top of the arch.
Cant: A term signifying an inclination
of an object from a perpendicular; to turn anything so that it does not
stand perpendicularly or square to a given object.
Cant Frame: A frame the plane of which
is not square to the keel.
Capstan, Steam: A vertical drum or
barrel operated by a steam engine and used for handling heavy anchor
chains, heavy hawsers, etc. The engine is usually non-reversing and
transmits its power to the capstan shaft through a worm wheel. The drum
is fitted with pawls to prevent overhauling under the strain of the
hawser or chain when the power is shut off. The engine may be
disconnected and the capstan operated by hand through the medium of
Cargo: Merchandise or goods accepted
for transportation by ship.
Cargo Boom: A heavy boom used in
loading cargo. See "boom."
Cargo Hatch: A large opening in the
deck to permit loading of cargo.
Cargo Mat: A mat, usually square and
made of manila rope, used to protect the deck covering while taking
stores, etc., on board.
Cargo Net: A square net, made in
various sizes of manila rope or chain, and used in connection with the
ship's hoisting appliances to load cargo, etc., aboard the vessel.
Cargo Port: An opening, provided with
a watertight cover or door, in the side of a vessel of two or more
decks, through which cargo is received and discharged.
Carlings: Short beams forming a
portion of the framing above deck openings. Also called headers when
they support the ends of interrupted deck beams.
Casings, Engine and Boiler Rooms: The
walls or partitions forming trunks above the engine and boiler spaces,
providing air and ventilation and enclosing the uptakes. They extend
somewhat above the weather deck, or superstructure deck if fitted, and
are of sufficient size to permit installation and removal of engines and
boilers. / Doors are fitted at the several deck levels to permit access
to the gratings and ladders.
Cavil: A heavy timber fastened to the
forward or after bitts about midway between the base and top to form a
cleat. The bitt so built.
Ceiling: A term applied to the
planking with which the inside of a vessel is sheathed. Also applied to
the sheet metal or wood sheathing in quarters and storerooms.
Ceiling, Floor: Planking fitted on top
of the floors or double bottom in the cargo holds.
Ceiling, Hold: Thick strakes of
planking fastened to the inside flanges or edges of the framing in the
Centerline: The middle line of the
ship from stem to stern as shown in any waterline view.
Center of Buoyancy: The geometric
center of gravity of the immersed volume of the displacement or of the
displaced water, determined solely by the shape of the underwater body
of the ship. It is calculated for both the longitudinal location,
forward or aft of the middle perpendicular, and the vertical location
above the base line or below the designed waterline.
Center of Flotation: The geometric
center of gravity of the water plane at which the vessel floats, forward
or aft of the middle perpendicular. It is that point about which a
vessel rotates longitudinally when actuated by an external force without
change in displacement.
Center of Gravity: The point at which
the combined height of all the individual items going to make up the
total weight of the vessel may be considered as concentrated; generally
located longitudinally forward or aft of the middle perpendicular and
vertically above bottom of keel or below a stated waterline.
Center of Lateral Resistance: The
point through which a single force could act and produce an effort equal
to the lateral resistance of the vessel. It is ordinarily assumed to be
coincident with the center of gravity of the immersed central
Center of Pressure: The point in a
sail or an immersed plane surface at which the resultant of the combined
pressure forces acts.
Central Lateral Plane: The immersed
longitudinal vertical middle plane of a vessel.
Chafing Plate: A plate fitted to take
the wear due to dragging moving gear or to protect ropes from wearing
where they rub on sharp edges. Also fitted on decks under anchor chains.
Chain Locker: Compartment in forward
lower portion of ship in which anchor chain is stowed.
Chain Locker Pipe: Chain Pipe: The
iron-bound opening or section of pipe leading from the chain locker to
the deck, through which the chain cable passes.
Chain Plate: A bar or plate secured to
the shell of a vessel to which the standing rigging is attached ..
Chains: Usually refers to heavy chains
attached to the anchor. Also applied to the lower parts of standing
rigging which are attached to the chain plates.
Chain Stopper: A device used to secure
the chain cable when riding at anchor, thereby relieving the strain on
the windlass, and also for securing the anchor in the housing position
in the hawsepipe.
Chamfer: A bevel surface formed by
cutting away the angle of two intersecting faces of a piece of material.
Chart House: A small room adjacent to
the bridge for charts and navigating instruments.
Chine: The line formed by the
intersection of side and bottom in ships having straight or slightly
Chock: A term applied to oval-shaped
castings, either open or closed on top, and fitted with or without
rollers, through which hawsers and lines are passed. Also applied to
blocks of wood used as connecting or reinforcing pieces, filling pieces,
and supports for life boats. Also applied to the brackets fitted to
boiler saddles to prevent fore and aft motion and to small brackets on
the webs of frames, beams and stiffeners to prevent tipping of the
Clamp: A metal fitting used to grip
and hold wire ropes. Two or more may be used to connect two ropes in
lieu of a short splice or in turning in an eye. Also a device generally
operated by hand, for holding two or more pieces of material together,
usually called a “C“clamp.
Cleats: Pieces of wood or metal, of
various shapes according to their uses, usually having two projecting
arms or horns upon which to belay ropes. The term Cavil is sometimes
applied to a cleat of extra size and strength.
CIinometer: An instrument used for
indicating the angle of roll or pitch of a vessel.
Cup: A four- to six-inch angle bar
welded temporarily to floors, plates, webs, etc. It is used as a
hold-fast which, with the aid of a bolt, pulls objects up close in
fitting. Also, short lengths of bar, generally angle, used to attach and
connect the various members of the ship structure.
Close Butt: A riveted joint in which
the ends of the connected members are brought into metal-to-metal
contact by grinding and pulling tight by clips or other means before the
rivets are driven.
Club-Foot: A fore foot in which
displacement or volume is placed near the keel and close to the forward
perpendicular, resulting in full water lines below water and fine lines
at and near the designed waterline, the transverse sections being
bulbshaped. Also called a bulb or bulbous bow.
Coaming, Bulkhead: A term applied to
the top and bottom strakes of bulkheads, which are usually made thicker
than the remainder of the plating and which act as girder web plates in
helping to support the adjacent structure.
Coaming, Hatch: A frame bounding a
hatch for the purpose of stiffening the edges of the opening and forming
the support for the covers. In a steel ship it generally consists of a
strake of strong vertical plating completely bounding the edges of a
Cofferdams: Empty spaces separating
two or more compartments for the purpose of insulation, or to prevent
the liquid contents of one compartment from entering another in the
event of the failure of the walls of one to retain their tightness.
Collar: A piece of plate or a shape
fitted around an opening for the passage of a continuous member through
a deck, bulkhead, or other structure to secure tightness against oil,
water, air, dust, etc.
Collier: A vessel designed for the
carrying of coal, which may or may not be fitted with special appliances
for coal handling.
Companion: The cover over a
Companionway: A hatchway or opening in
a deck provided with a set of steps or ladders leading from one deck
level to another for the use of personnel.
Compartment: A subdivision of space or
room in a ship.
Composite Vessel: A vessel with a
metal frame and a wooden shell and decks.
Cordage: A comprehensive term for all
ropes of whatever size or kind on board a ship.
Counter: That part of a ship's stern
which overhangs the stern post, usually that part above the water line.
Countersink: A term applied to the
operation of cutting the sides of a drilled or punched hole into the
shape of the frustum of a cone. Also applied to the tool by which
countersinking is done.
Countersunk Hole: A hole tapered or
beveled around its edge to allow a rivet or bolt head or a rivet point
to seat flush with or below the surface of the riveted or bolted object.
Countersunk Rivet: A rivet driven
flush on one or both sides.
Coupling: A device for securing
together the adjoining ends of piping, shafting, etc., in such a manner
as will permit disassembly whenever necessary. Flanges connected by
bolts and pipe unions are probably the most common forms of couplings.
Cradle: A support of wood or metal
shaped to fit the object which is stowed upon it.
Cradle, Boat: The heavy wood or metal
supports for a ship's boat, cut to fit the shape of the hull of the boat
and usually faced with leather, In which the boat is stowed.
Cradle, Launching: The structure of
wood, or wood and steel, which is built up from the sliding ways,
closely fitting the shell plating, which supports the weight of the ship
and distributes it to the sliding ways when a ship is being launched.
The extent of the cradle and the number of sections into which it may be
divided depends on the weight and length of the ship.
Cradle, Marine Railway: The carriage
on which the ship rests when being docked on a marine rail way.
Crane: A machine used for hoisting and
moving pieces of material or portions of structures or machines that are
either too heavy to be handled by hand or cannot be handled economically
by hand. Bridge, gantry, jib, locomotive, and special purpose cranes are
used in shipyards.
Cribbing: Foundations of heavy blocks
and timbers for supporting a vessel during the period of construction.
Cross Trees: A term applied to athwart
ship pieces fitted over the trees on a mast. They serve as a foundation
for a platform at the top of a mast or as a support for outriggers.
Crown: Term sometimes used denoting
the round-up or camber of a deck. The crown of an anchor is located
where the arms join the shank.
Crow's Nest: A lookout station
attached to or near the head of a mast.
Crutch: A term applied to a support
for a boom. Also applied to the jaw of a boom or gaff.
Cutwater: The forward edge of the stem
at or near the water line is called the cutwater.
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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 term 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 amount which the
straight portion of the bottom of the floor, of the midship section
rises above the base line in the half-beam of the vessel. Usually
expressed in inches.
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.
Deadwood: The vertical surfaces at the
extreme after body of a ship.
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 beams 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 Machinery: A term applied to
capstans, windlasses, winches, and miscellaneous machinery located on
the decks of 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 calked.
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.
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 also may be used for cargo.
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 topping lift, and necessary rigging for hoisting
heavy weights, cargo, etc.
Diagonal Line: A line cutting the body
plan diagonally from the centerline, 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 weight 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
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.
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.
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.
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.
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
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
Donkey Engine: A small gas, steam, or
electric auxiliary engine set on deck and used for lifting, etc.
Door, Airtight: A door so constructed
that when dosed it will prevent the passage of air under a small
pressure. Used on air locks to boiler rooms under forced draft and in
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 dosed, 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
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.
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, 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 hollow 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 underwater portions of vessels and for docking a
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 practicality 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 I 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 dock 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 under
water 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 wildcat 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."
Dunnage: Any material, such as blocks,
boards, paper, burlap, etc., necessary for the safe stowage of stores
Dutchman: A piece of wood or steel
fitted into an opening to cover up poor joints or crevices caused by
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Edge, Sight: That edge of a strake of
plating which laps outside another strake and is, therefore,
in plain sight.
Elbow-EIl: A pipe fitting that makes
an angle between adjacent pipes, always 90 degrees unless another angle
Electrode: Either a positive or
negative pole or terminal in an electric circuit; rod used to make an
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
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,
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
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
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.
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 hawsepipes are
usually run down through the eyes of a ship.
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Fabricate: To shape, assemble, and
secure in place the component parts in order to form a complete whole.
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
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 frustum 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.
Fall: The entire length of rope used
in a tackle. 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.
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.
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
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 sail makers and riggers to
open the strands of a rope, eye, grommet, etc. A "hand fid" is rounded
at the end; 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 Dee: 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 l1letal
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 the hull, etc.
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.
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 the
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
Flat: A small partial deck, built
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
Floodable Length: The length of
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
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
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.
Fore Peak: The extreme forward end of
the vessel below decks. The forward trimming tank.
Forward: In the direction of the
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,
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,
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.
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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 the water in the tube.
Galley: The space on a vessel in
which the food is prepared and cooked.
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 GirtIine: 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.
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.
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 ships
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
Gooseneck: A swiveling fitting on the
heel or mast end of a boom for connecting the boom to the mast.
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
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 positions in the davits.
Grommet: A wreath or ring of rope.
Fiber, 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 Ledge: 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 windless. 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 a 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
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
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, 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
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
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 ships, steel hatch
covers. 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 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
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.
Also a term used to describe the advancement of a merchant seaman as in
coming up the Hawsepipe as opposed to academy training.
Hawser: A large rope or a cable used in warping, towing, and mooing.
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
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 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.
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.
Horsing: Calking planking with oakum
with a large maul or beetle and a wedge-shaped iron.
Housing: A term applied to an
enclosure 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
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Inboard: Toward the center.
Inboard Profile: A plan representing
a longitudinal section through the center of the ship, showing deck
heights, transverse bulkheads, assignment of space, machinery, etc.,
located on the center plane or between the center and the shell on the
Initial Stability: The stability of a
vessel in the upright position or at small angles of inclination. It is
measured by the metacentric height.
Inner Bottom: A term applied to the
inner skin or tank top plating. The plating over the double bottom.
Intercostal: Occurring between ribs,
frames, etc. The term is broadly applied, where two members of a ship
intersect, to the one that is cut.
Isherwood System: A system of
building ships which employs close spaced, relatively light,
longitudinal main framing supported on widespread transverse members of
comparatively great strength instead of transverse main framing.
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Jack Ladder: A ladder with wooden
steps and side ropes.
Jack rod - A term applied to a pipe or
rod to which the edges of awnings or weather cloths are secured.
Jack staff: Flagpole at the bow of a
Jacob's Ladder: A ladder having either fiber or wire rope or chain
sides with wood or metal rungs attached at regular intervals. One end is
usually fitted with sister hooks or shackles for hooking on.
Joggled: A term applied where a plate
or bar is offset in the way of a lapped joint. The object of the joggle
is to permit a close fit of the attached member without the use of
liners under alternate strakes of plating.
Joint, Butt: A term applied where a
connection between two pieces of material is made by bringing their ends
or edges together (no overlap) and by welding alone, or by welding,
riveting, or bolting each to a strip or strap that overlaps both pieces.
Joint, Lapped: A term applied where a
connection between two pieces of material is made by overlapping the end
or edge of one over the end or edge of the other and by fastening the
same by bolts, rivets, or welding.
Journal: That portion of a shaft or
other revolving member which transmits weight directly to and is in
immediate contact with the bearing in which it turns.
Jury: A term applied to temporary
structures, such as masts, rudders, etc., used in an emergency.
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center-line strength member running fore and aft along the bottom of a
ship and often referred to as the backbone. It is composed either of
long bars or timbers scarfed at their ends or by flat plates connected
together by riveting or welding.
Keel, Bilge: A fin fitted on the bottom of a ship at the turn of the
bilge to reduce rolling. It commonly consists of a plate running fore
and aft and attached to the shell plating by angle bars. It materially
helps in steadying a ship and does not add much to the resistance to
propulsion when properly located.
Blocks: Heavy timber blocks piled one above the other on which the keel
of a vessel is supported when being built, or when she is in a dry dock.
They are placed under the keel from bow to stern and a sufficient
distance apart to allow working between them.
Docking: In dry docking, the weight of a ship is usually carried almost
entirely on the keel blocks. The keel and keelson provide the means of
distributing the pressure on the center line, and docking keels composed
of doubling strips of plate or a heavier plate or built-up girders are
sometimes fitted on the bottom at a distance from the center line
corresponding to the best position for the side keel blocks. The docking
keels are fitted in the fore and aft direction, generally parallel or
nearly so to the keel.
Vertical Center: The lower centerline girder which, in conjunction with
a flat plate keel on the bottom and a rider plate on top, forms the
principal fore-and-aft strength member in the bottom of a ship. In
addition to its importance as a “backbone" or longitudinal strength
member, it serves to distribute and equalize the pressure on the
transverse frames and bottom of the ship when grounding or docking
occurs. In steel ships this keelson usually consists of a vertical plate
with two angles running along the top and two along the bottom. The
girder, however, may be made up of various combinations of plates and
shapes. This member should continue as far forward and aft as possible.
Usually called the Vertical Keel.
Post: A strong vertical post used to support a derrick boom. See Samson
block of wood having a natural angular shape or one cut to a bracket
shape and used to fasten and strengthen the corners of deck openings and
the intersections of timbers, and to connect deck beams to the frames of
wood vessels. The term is also applied to the ends of steel deck beams
that are split, having one leg turned down and a piece of plate fitted
between the split portion, thus forming a bracket or knee.
unit of speed, equaling one nautical mile (6,080.20 feet) an hour, as
when a ship goes ten nautical miles per hour, her speed is ten knots.
An abrupt change in direction of the plating, frames, keel, deck, or
other structure of a vessel.
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A framework consisting of two parallel sides connected by bars
or steps which are spaced at intervals suitable for ascending
or descending. On shipboard the term ladder is also applied to
staircases and to other contrivances used in ascending or
descending to or from a higher or lower level.
Accommodation: A staircase suspended over the side of a vessel from a
gangway to a point near the water to provide easy access to the deck
from a small boat alongside.
Companion: A staircase fitted as a means of access from a deck to the
Sea: Rungs secured to the side of a vessel to form a ladder from the
weather deck to the water.
A term applied to the insulating material that it fitted on the outside
of boilers, piping, etc.
Landing Edge: That portion of the edge or end of a plate over which
another plate laps. The covered-up edge.
The present use of this term is generally limited to a piece of rope or
line having one end free and the other attached to any object for the
purpose of either near or remote control.
term applied to the distance that one piece of material is laid over
another; the amount of overlap, as in a lapped joint.
Launching: A term applied to the operation of transferring a vessel
from the building ways into the water. End launching and side launching
methods are employed; the former method is used when the vessel is built
at an angle, usually at right angles, to the waterfront and the vessel
is launched stern first, while in side launching the vessel is built
parallel to the waterfront and launched sidewise. In preparing for an
end launching, usually groundways made of heavy timbers are laid with an
inclination of about 1/2" to 5/8" to the foot parallel to the center
line of the ship one on either side of the keel, and spaced about
one-third of the beam of the vessel apart. These groundways run the
length of the vessel and for some distance out under the water. On top
of the groundways are placed the sliding ways, also heavy timbers, and
between these two ways is placed a coating of launching grease. The
sliding ways are prevented from sliding on the greased groundways by a
trigger or similar device and dog or dagger shores. Cradles are built up
to fit the form of the vessel, and between the sliding ways and the
cradle, wedges are driven and the weight of the ship thus transferred
from the building blocks to the sliding ways. After the building blocks
and shores are removed, the trigger is released and gravity causes the
vessel to slide down the inclined ways. In Some cases hydraulic jacks
are set at the upper end of the groundways to exert pressure on the
sliding ways to assist in overcoming initial friction along the ways. A
similar procedure is followed in the case of side launchings, except
that more than two groundways are usually used, depending on the length
of the ship, and the inclination of the ways is steeper.
Off: Is a term applied to the work done by a loftsman in laying off the
ship's lines to full size in the mold loft and making templates
therefrom. Also known as laying down.
Out: Placing the necessary instructions on plates and shapes for
shearing, planing, punching, bending, flanging, beveling, rolling, etc.,
from templates made in the mold loft or taken from the ship.
Edge: That edge of a propeller blade which cuts the water when the
screw is revolving in the ahead direction. That edge of a rudder, diving
plane, or strut arm which faces toward the bow of the ship.
between Perpendiculars: The length of a ship measured from the forward
side of the stem to the aft side of the stern post at the height of the
designed water line. In naval practice, the total length on the designed
Over All: The length of a ship measured from the foremost point of the
stem to the aftermost part of the stern.
Template: To construct a template to the same size and shape as the
part of the ship involved, from either the mold loft lines or from the
ship itself, from which laying out of material for fabrication may be
Transferring marks and measurements from a drawing, model, etc., to a
plate or other object, by templates or other means.
Port: An opening in a ship's side, provided with a glazed lid or cover.
Lightening Hole: A hole cut out of any structural member, as in the
web, where very little loss of strength will occur. These holes reduce
the weight and in many cases serve as access holes. This condition is
particularly true in floor plates and longitudinals in double bottom.
A full-bodied, heavily-built craft, usually not self-propelled, used in
bringing merchandise or cargo alongside or m transferring same from a
Chains: Chains passing through the limber holes of a vessel, by which
they may be cleaned of dirt.
Hole: A hole or slot in a frame or plate for the purpose of preventing
water from collecting. Most frequently found in floor plates just above
the frames and near the center line of the ship.
general term for a rope of any size used for various purposes: small
cords such as log line, lead line, or small stuff as marlin, ratline,
piece of metal used for the purpose of filling up a space between a bar
and a plate or between two plates; filler.
The plans of a ship that show its form. From the lines drawn full size
on the mold loft floor are made templates for the various parts of the
The deviation of a vessel from the upright position, due to bilging,
shifting of cargo, or other cause.
Line: The line 18 inches long and 1 inch wide on each side of the ship
at the midship section, which indicates the maximum draft to which the
ship may be loaded.
A storage compartment on a ship.
A man who lays off the ship's lines to full size in the mold loft and
makes templates therefrom.
Longitudinals: A term applied to the fore-and-aft frames in the bottom
of a ship. These frames are usually made up from plates and shapes and
are sometimes intercoastal and sometimes continuous.
A small opening to permit the passage of air for the purpose of
ventilation, which may be partially or completely closed by the
operation of overlapping shutters.
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Magazine: Spaces or compartments devoted to the stowage of
ammunition. Often specifically applied to compartments for the
stowage of powder as a distinction from shell stowage spaces.
Body: The hull proper, without the deck houses, etc.
Deck: The principal deck of the hull, usually the highest extending
from stem to stern and providing strength to the main hull.
A term applied to the manger-like space immediately forward of the
manger plate which is fitted just abaft the hawsepipes to prevent water
entering through the pipes from running aft over the deck.
A round or oval hole cut in decks, tanks, boilers, etc., for the purpose
of providing access.
Manifold: A casting or chest containing several valves. Suction or
discharge pipes from or to the various compartments, tanks, and pumps
are led to it, making it possible for a pump to draw from or deliver to
anyone of several compartments.
Plank: A plank forming the boundary or margin of the deck planking.
Plate: The outer boundary of the inner bottom, connecting it to the
shell plating at the bilge.
Railway: See dry dock, railway.
Spike: A pointed iron or steel tool used to separate the strands in
splicing rope, and as a lever in marling or putting on seizings. The
wire rope spike has a flat, rounded end and the manila rope spike has a
A double-threaded, left-handed tarred cord, about 1/8" diameter, made of
a good grade of American hemp.
long pole of steel or wood, usually circular in section, one or more of
which are usually located, in an upright position, on the center line of
a ship. Originally intended for carrying sails, they are now used more
as supports for the rigging, cargo and boat-handling gear and wireless
Collar: A piece of wood or a steel shape formed into a ring and fitted
around the mast hole in a deck.
Hounds: The upper portion of the mast at which the outrigger or trestle
trees are fitted. Also applied to that portion at which the hound band
for attaching the shrouds is fitted on masts with out outrigger or
Partners: A term applied to wood planking or steel plating worked
around a mast hole to give side support to the mast.
Step: A term applied to the foundation art which a mast is erected.
Table: See Boom Table.
A space or compartment where members of the crew eat their meals; a
Beam: A deck beam located at the midpoint between the forward and after
perpendiculars. Also applicable to the transverse dimension of the hull
at the same point.
Frame: The frame located at the midpoint between the perpendiculars.
Section: The vertical transverse section located at the midpoint
between the forward and after perpendiculars. Usually this is the
largest section of the ship in area. Also, applied to a drawing showing
the contour of the mid ship frame upon which is depicted all the
structural members at that point with information as to their size and
Same as Amidships.
Cut to an angle of 45 degrees or two pieces joined to make a right
To build up of wood or light material to scale or full size a portion of
the ship before actual fabrication of the steel work. Used to study
arrangement, methods of fabrication, workability, etc.
pattern or template. Also a shape of metal or wood over or in which an
object may be hammered or pressed to fit.
Line: A datum line from which is determined the exact location of the
various parts of a ship. It may be horizontal and straight as the molded
base line, of curved as a molded deck line or a molded frame line. These
lines are determined in the design of a vessel and adhered to throughout
the construction. Molded lines are those laid down in the mold loft.
Edge: The edge of a ship’s frame which comes in contact with the skin,
and is represented in the drawings.
Loft: A space used for laying down the lines of a vessel to actual size
and making templates therefrom for laying out the structural work
entering into the hull.
A term applied to the operation of anchoring a vessel in a harbor,
securing her to a mooring buoy, or to a wharf or dock by means of chains
Lines: The chains or ropes used to tie up a ship.
Pipe: An opening through which mooring lines pass.
A hole cut in any material to receive the end or tenon of another piece.
A ship driven by some form of internal combustion engine. Not generally
applied to small boats driven by gasoline engines which are usually
Ventilator: A ventilator whose top is shaped like a mushroom and fitted
with baffle plates so as to permit the passage of air and prevent the
entrance of rain or spray. Located on or above a weather deck to furnish
ventilation to compartments below deck.
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Mile: See knot.
Plank: A margin plank that is notched to take the ends of regular deck
planks and insure good calking of the joint.
Niggerhead: A small auxiliary drum on a winch. See Gypsy.
Pin: A metal pin fitted in a towing post or bitt for belaying the line.
The parts of a stair tread which projects beyond the face of the riser.
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substance made from soft vegetable fiber such as hemp and jute
impregnated with pine tar. It is principally used for calking the
planking on wood decks of steel vessels and for calking all the planking
on wood ships where watertightness is desired. It is also used for
calking around pipes.
A term used by draftsmen and loftsmen for the coordinates in ship
curves. Also applied to joggles in plates and shapes of structural
Having the property of resisting the passage of oil.
A heavy bar of iron or steel bent in the form of a Z used to hold a
portable drill. One leg is bolted or clamped to the work to be drilled
and the drill head is placed under the other leg which holds down the
drill to its work.
Board: On or in a ship; aboard.
On the weather deck, in the open air.
Deck: The term formerly applied to the lowest deck in a ship; now
Outboard: Away from the center toward the outside; outside the hull.
Profile: A plan showing the Longitudinal exterior of the starboard side
of a vessel, together with all deck erections, stacks, masts, yards,
rigging, rails, etc.
Bottom: A term applied to the bottom shell plating in a double-bottom
Overboard: Outside over the side of a ship into the water.
Overhang: That portion of a vessel's bow or stern which projects beyond
a perpendicular at the waterline.
Overhaul: To repair or put in proper condition for operation; to
overtake or close up the distance between one ship and another ship
moving in the same direction.
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A general term applied to a yielding material employed to affect a tight
joint, also called gasket material.
A fitting having one or more eyes integral with a plate or base to
provide ample means of securing and to distribute the strain over a wide
area. The eyes may be either "worked" or "shackle." Also known as lug
pads, hoisting pads, etc.
A length of rope secured at the bow of a small boat for use in towing or
for making it fast. Called also a bow-fast.
The fluke, or more exactly, the flat inner surface of the fluke of an
anchor; a sailmaker's protector for the hand, used when sewing canvas; a
flat surface at the end of a strut or stanchion for attachment to
plating, beams, or other structural member.
The pulsation in and out of the bow and stern plating as the ship
alternately rises and plunges deep into the water.
Beams: The transverse beams that tie the panting frames together.
Frames: The frames in the fore peak, usually extra heavy to withstand
the panting action of the shell plating.
The Paravane is a special type of water kite which, when towed with wire
rope from a fitting on the forefoot of a vessel, operates to ride out
from the ship's side and deflect mines which are moored in the path of
the vessel, and to cut them adrift so that they will rise to the surface
where they may be seen and destroyed.
Parcelling: Narrow strips of canvas which are tarred and wound around
ropes, following the lay and overlapping in order to shed water. The
parcelling is applied after worming, preparatory to serving.
Partners: Similar pieces of steel plate, angles, or wood timbers used
to strengthen and support the mast where it passes through a deck, or
placed between deck beams under machinery bed plates for added support.
term applied to a short piece of metal so hinged as to engage in teeth
or depressions of a revolving mechanism for the purpose of preventing
recoil. Fitted to capstans, windlasses, etc. Also called Pall.
The operation of filling the seams of a wood deck, after the calking had
been inserted, with pitch, marine glue, etc. Also applied to the
operation of slackening away on a rope or chain.
fore and after: The space at the extreme bow or stern of a vessel below
Tank: Compartments at the extreme fore and aft ends of the ship for any
use either as void spaces or as trimming tanks. When used for the latter
purpose, water is introduced to change the trim of the vessel.
round off or shape an object, smoothing out burrs and rough edges.
Hook: A type of quick releasing hook used at the lower end of shrouds,
on boat grips, and in similar work where fast work may be necessary.
Roll: The time occupied in performing one double oscillation or roll of
a vessel as from port to starboard and back to port.
Periscope: An instrument used for observing objects from a point below
the object lens. It consists of a tube fitted with an object lens at the
top, an eye piece at the bottom and a pair of prisms or mirrors which
change the direction of the line of sight. Mounted in such a manner that
it may be rotated to cover all or a part of the horizon or sky and
fitted with a scale graduated to permit of taking bearings, it is used
by submarines to take observations when submerged.
A vertical member or column giving support to a deck. Also called a
House: A house designed for navigational purposes. It is usually
located forward of the midship section and so constructed as to command
an unobstructed view in all directions except directly aft along the
center line of the vessel where the smokestack usually interferes.
BeIaying: A small iron or tough wood pin, made with a head, shoulder,
and shank. It is fitted in holes in a rail and is used in belaying or
making fast the hauling parts of light running gear, signal halyards,
A term applied to the pins or bolts which hinge the rudder to the
gudgeons on the stern post.
term applied to the distance a propeller will advance during one
revolution, the distance between the centers of the teeth of a gear
wheel, the axial advance of one convolution of the thread on a screw,
the spacing of rivets, etc. Also applied to pine tar, asphalt and coal
pitch used in paying seam of a deck.
Pitching: The alternate rising and falling motion of a vessel's bow in
a nearly vertical plane as she meets the crests and troughs of the
The localized corrosion of iron and steel in spots, usually caused by
irregularities in surface finish, and resulting in small indentations or
Point: That point during the progress of a launching at which the
moment of buoyancy about the fore poppet equals the moment of the
vessel's weight. At this point the stern begins to lift and the vessel
pivots about the fore poppet. Also the point about which the ship
appears to rotate when it is making a turn.
drawing prepared for use in building a ship.
Paneling: Wood covering for decks, etc. The shell of wood boats.
Platform: A partial deck.
Shell: The plating forming the outer skin of a vessel. In addition to
constituting a watertight envelope to the hull, it contributes largely
to the strength of the vessel.
Mark: A mark painted on the sides of a vessel designating the depth to
which the vessel may, under the maritime laws, be loaded in different
bodies of water during various seasons of the year.
A scow-shaped boat used in connection with engineering and military
operations such as transporting men and equipment, bridge construction,
supports for temporary bridges, salvage work etc. Also applied to
cylindrical air and watertight tanks or floats used in salvage
Poop Deck: The structure or raised deck at the after end of a vessel.
Those pieces of timber which are fixed perpendicularly between the
ship's bottom and the bilgeways at the foremost and aftermost parts of
the ship, to support it when being launched. They are parts of the
The left-hand side of a ship when looking from aft forward. Also an
Air: See air port.
Gangway: An opening in the side plating, planking, or bulwark for the
purpose of providing access through which people may board or leave the
ship or through which cargo may be handled.
Porthole: See air port.
Strain: The test load applied to anchors, chains, or other parts,
fittings, or structure to demonstrate proper design and construction and
Strength: The proof strength of a material, part, or structure is the
strength which it has been proved by test to possess.
Propeller: A propulsive device consisting of a boss or hub carrying,
radial blades, from two to four in number. The rear or driving faces of
the blades form portions of an approximately helical surface, the axis
of which is the center line of the propeller shaft.
Aperture: The opening in the stern frame of single-screw ships for the
Arch: The arched section of the stern frame above the propeller.
Guard: A framework fitted somewhat below the deck line on narrow,
high-speed vessels with large screws, so designed as to overhang and
thus protect, the tips of the propeller blades.
Thrust: The effort delivered by a propeller in pushing a vessel ahead.
archaic term for the bow of a ship.
Pudding: Pads constructed of old rope, canvas, oakum, etc., sometimes
leather covered, in any desired shape and size and used to prevent
chafing of boats, rigging, etc., and on the stem of a boat to lessen the
force of a shock.
machine for punching holes in plates and shapes.
Prick: A small punch used to transfer the holes from the template to
the plate. Also called a "center punch."
Purchase: Any mechanical advantage which increases the power applied.
The upper part of a vessel's sides near the stern; also portions of the
vessel's sides about midway between the stern and midlength and between
midlength and the stern. The part of a yard just outside the slings.
Quarters: Living spaces for passengers or personnel. It includes
staterooms, dining salons, mess rooms, lounging places, passages
connected with the foregoing, etc.; individual stations for personnel
for fire or boat drill, etc.
artificial wall or bank, usually of stone, made toward the sea or at the
side of a harbor or river for convenience in loading and unloading
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A groove, depression, or offset in a member into which the end or edge
of another member is fitted, generally so that the two surfaces are
flush. A rabbet in the stern or keel would take the ends or edges of the
planking or shell plating.
Deformation of the section of a ship, generally applied to a transverse
section, so that one set of diagonals in the plane of action is
shortened while those at right angles thereto are lengthened.
Room: A room, usually sound-proofed, used for sending and receiving
Life: A frame work fitted with air chambers to support a number of
people in case of accidents. Carried on deck and light enough to be
handled without mechanical means.
The upper edge of the bulwarks. Also applied to the tiers of guard rods
running between the top rail and the deck where bulwarks are not fitted.
term applied to the fore and aft inclination from the vertical of a
mast, smokestack, stempost, etc.
Galley: The stove, situated in the galley, which is used to cook the
food. The heat may be generated by coal, fuel oil, or electricity.
Guard: A dished, circular piece of metal made in two parts and fitted
closely on hawsers and lines to prevent rats boarding or leaving a ship
while at a dock or wharf. The concave side is placed toward the shore to
prevent boarding and the guard is reversed to prevent rats leaving the
Ratlines: Short lengths of ratline stuff secured to the shrouds
parallel to the waterline and serving as ladder rungs for the crew to
ascend or descend.
Enlarging a hole by the means of revolving in it a cylindrical slightly
tapered tool with cutting edges running along its sides.
Gear: An arrangement of shafts and gears such that the number of
revolutions of the output shaft is less than of the input shaft -
generally used between a motor or a steam turbine shaft and the
The act of passing the end of a rope or chain through an opening, as
passing a rope through a block.
Frame: An angle bar or other shape riveted to the inner edge of a
transverse frame to reinforce it.
A fore-and-aft wooden strip or heavy batten used to support the
transverse frames temporarily after erection.
term applied to the transverse frames of a boat.
To float in a buoyant manner while being towed or lying at anchor.
Plate: A continuous flat plate attached to the top of a center line
vertical keel in a horizontal position. It’s under side is attached to
the floors, and when an inner bottom is fitted, it forms the center
A term used collectively for all the ropes and chains employed to
support the masts, yards, and booms of a vessel, and to operate the
movable parts of same.
Bottom: See deadrise.
The upright board of a stair. A pipe extending vertically and having
A metal pin used for connecting two or more pieces of material by
inserting it into holes punched or drilled in the pieces and upsetting
one or both ends. The end that bears a finished shape is called the head
and the end upon which some operation is performed after its insertion
is called the point. Small rivets are "driven cold," i.e., without
heating, and large ones are heated so that points may be formed by
Riveting: The art of fastening two pieces of material together by means
Chain: A term applied to an arrangement of the rivets in adjoining rows
where the centers of the rivets are opposite each other and on a line
perpendicular to the joint.
Staggered or Zig-Zag: A term applied to an arrangement of the rivets in
adjoining rows where the rivets in alternate rows are one-half the pitch
or spacing ahead of those in the other rows.
Line of: A term applied to a continuous line of rivets whose centers
fall on a line perpendicular to the joint.
Row of: A term applied to a continuous row of rivets whose centers fall
on a line parallel to the joint. Joints made by one row of rivets are
known as single-riveted joints; by two rows, as double-riveted joints;
by three rows, as treble-riveted joints; by four rows, as
quadruple-riveted joints; etc.
Motion of the ship from side to side, alternately raising and lowering
each side of the deck.
Chocks: Same as keel, bilge.
The product resulting from twisting a fibrous material, such as manila,
hemp, flax, cotton, coir, etc., into yarns or threads which in turn are
twisted into strands and several of these are laid up together. Fiber
rope is designated as to size by its circumference. Wire rope is made of
iron, steel, or bronze wires, with or without a fiber core or heart,
twisted like yarns to form strands which are laid up to form the rope.
Wire rope is designated as to size both by its diameter and by its
Lay: The direction in which a rope is twisted up.
Ridge: A rope running through the eyes at the heads of the awning
stanchions to which the edge of an awning is hauled out and stopped. The
term “center ridge rope” is applied to the rope supporting the center of
Worming: Filling in the contlines of a rope with marline. The marline
should run with the lay of the rope.
Strip: A plate riveted to the bottom of the keel to afford protection
in docking and grounding. A strip fastened to the face of a fender or to
the shell plating where contact is likely to occur.
A device used in steering or maneuvering a vessel. The most common type
consists of a flat slab of metal or wood, hinged at the forward end to
the stern or rudder post. When made of metal, it may be built up from
plates, shapes, and castings, with or without wood filling, or it may be
a casting. The rudder is attached to a vertical shaft called the rudder
stock, by which it is turned from side to side.
Balanced: A rudder having the leading edge of a whole or a part of its
area forward of the center line of the rudder stock thus reducing the
torque required to turn the rudder.
Bands: The bands that are placed on each side of a rudder to help brace
it and tie it into the pintles.
Chains: The chains whereby a rudder is sometimes fastened to the stern.
They are shackled to the rudder by bolts just above the water line, and
hang slack enough to permit free motion of the rudder. They are used as
a precaution against losing a rudder at sea. These chains are also
called "rudder pendants.”
Frame: A term applied to a vertical main piece and the arms that
project from it which forms the frame of the rudder. It may be a
casting, a forging, or a weldment.
PintIes: See pintles.
Post - See Stern post.
Stock: A vertical shaft having a rudder attached to its lower end and
having a yoke, quadrant or tiller fitted to its upper portion by which
it may be turned.
Stops: Fittings attached to the ship structure or to shoulders on the
rudder post to limit the swing of the rudder.
Trunk: A watertight casing fitted around a rudder stock between the
counter shell plating and a platform or deck, usually fitted with a
stuffing box at the upper end.
Underhung: A rudder that is not hinged to or stepped on the stern post
but is supported entirely by the rudder stock and the rudder stock
underwater portion of a vessel aft of the midship section or flat of the
bottom. That portion of the after hull that tapers to the stern post.
Rigging: Ropes which are hauled upon at times in order to handle and
adjust sails, yards, cargo, etc., as distinguished from standing rigging
which is fixed in place.
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The deformation or yielding caused when the middle portion of a
structure or ship settles or sinks below its designed or accustomed
position. The reverse of hogging.
Tracks: A device fitted on the after side of a mast in which slides,
secured to the forward edge of a fore-and -aft sail, travel up and down
the mast as the sail is hoisted or lowered; used in lieu of mast hoops.
Post: A strong vertical post that supports cargo booms. See king post.
Scantlings: A term applied to the dimensions of the frames, girders,
plating, etc., that enter into a ship's structure.
An end connection made between two pieces of material by tapering them
so that they will fit together in a joint of the same breadth and depth
as the pieces.
Bulkhead: A light bulkhead used as a shelter from an excess of heat,
cold, or light, or to conceal something from sight.
Board: A large board made of soft, clear, planed lumber, sometimes a
section of the mold loft floor, on which a full-sized body plan of a
ship is drawn. The lines were formerly cut in by the use of a scriving
knife, which made a small U-shaped groove to prevent them from being
obliterated. Pencil lines have taken the place of cutting to a large
extent. It is used in making templates of frames, beams, floors, etc.,
and in taking off dimensions. It is sanded smooth after it has served
Pipe: A pipe conducting the water from a deck scupper to a' position
where it is discharged overboard.
Drains from decks to carry off accumulations of rain water or sea water.
The scuppers are placed in the gutters or waterways on open decks and in
corners of enclosed decks and connect to pipes leading overboard.
A small opening, usually circular in shape and generally fitted in decks
to provide access. Often termed escape scuttles, and when fitted with
means whereby the covers can be removed quickly to permit exit are
called quick acting scuttles.
Butt: The designation for a container of the supply of drinking water
for the use of the crew.
Chest: An arrangement for supplying seawater to condensers and pumps,
and for discharging waste water from the ship to the sea. It is a cast
fitting or a built-up structure located below the waterline of the
vessel and having means for attachment of the piping. Suction sea chests
are fitted with strainers or gratings.
Sea Connection: A sea valve secured to the plating of the vessel below
the waterline for use in flooding tanks, magazines, etc., to supply
water to pumps, and for similar purposes.
term applied to an edge joint.
A term applied to a strip of plate serving as a connecting strap between
the butted edges of plating. Strap connections at the ends are called
Iron: A bar of soft iron used on the bending slab as a form to which to
bend frames into the desired shapes.
To wrap any small stuff tightly around a rope which has been previously
wormed and parcelled. Very small ropes are not wormed.
To tighten the nut on a bolt or stud; to bring the shrouds of a mast to
a uniform and proper tension by adjusting the rigging screws or the
lanyards through the dead eyes.
Bolt: A pin or bolt that passes through both eyes of a shackle and
completes the link. The bolt may be secured by a pin through each end,
or a pin through one end and through the eye, or by having one end and
one eye threaded, or one end headed and a pin through the other.
Shafting: The cylindrical forging, solid or tubular, used for
transmission of rotary motion from the source of power, the engine, to
Angle: The angle between the center line of the shaft and the center
line of the ship is the horizontal angle and the angle between the
center line of the shaft and either the base line or the designed
waterline is the vertical angle.
Alley: A watertight passage, housing the propeller shafting from the
engine room to the bulkhead at which the stern tube commences. It
provides access to the shafting and its bearings and also prevents any
damage to the same from the cargo in the spaces through which it passes.
Coupling: The means of joining together two sections of a shaft,
usually by means of bolts through flanges on the ends of the sections of
Pipe: See Stern Tube.
Strut: A term applied to a bracket supporting the outboard after end of
the propeller shaft and the propeller in twin or multiple-screwed
vessels having propeller shafts fitted off the center line. It usually
consists of a hub or boss, fitted with a bushing, to form a bearing for
the shaft, and two streamlined arms connecting it to the side of the
ship. The inboard ends of the arms are fitted with palms for attachment
to the shell or to interior framing.
bar of constant cross section such as a channel, T-bar, angle bar, etc.,
either rolled or extruded.
Cutting, bending, and fanning a structural member.
Large machines for cutting plates or shapes.
Legs: A rig for handling heavy weights, consisting of an A-frame of
timber or steel with the top overhanging the base, having the lower ends
fixed or pivoted and the top ends held either by fixed stays or by
topping lifts which permit change of slope of the legs. Tackles are
secured at the top of the frame through which the hoisting rope or cable
is run. Sometimes called sheers.
Sheathing: A term applied to the wood planking fitted over a steel
deck, to the planking fitted over the underwater portion of a steel
hull, and to the copper or alloy sheets with which the bottom of a wood
ship, or a steel ship sheathed with wood, is covered.
A wood or metal disk, having a groove around its cylindrical surface to
permit a rope or chain to run over it without slipping off and a bushing
for bearing on the pin or bolt on which it revolves.
Holes: A term applied to apertures in masts, booms, and spars in which
sheaves are installed.
The longitudinal curve of a vessel's rails, decks, etc., the usual
reference being to the ship's side; however, in the case of a deck
having a camber, its center line may also have a sheer. The amount by
which the height of the weather deck at the after or forward
perpendicular exceeds that at its lowest point.
Plan: A side elevation of the ship's form.
Strafe: The topmost continuous strake of the shell plating usually made
thicker than the side plating below it.
wood ship term applied to the fore and aft timber that is fastened to
the frames to form a support for the ends of the beams. See clamp.
Expansion: A plan showing the shapes, sizes, and weights of all plates
comprising the shell plating, and details of their connections.
Landings: Points marked on the frames to show where the edges of the
shell plates are to be located.
Deck: A term applied to a deck fitted from stem to stern on a
relatively light superstructure.
Butts: An arrangement of butts in longitudinal or transverse structural
members whereby the butts of adjacent members are located a specified
distance from one another, measured in the line of the members.
piece of wood or iron let into a slack place in a frame, plank, or plate
to fill out a fair surface or line. Also applied to thin layers of metal
or other material used to true up a bed plate or machine or inserted in
bearings to permit adjustment after wear of the bearing.
Shipshape: A nautical term used to signify that the whole vessel, or
the portion under discussion, is neat in, appearance and in good order.
Pieces of timber placed in a vertical or inclined position to support
some part of a ship, or the ship itself during construction or while in
Spur or Side: A piece of timber placed in a nearby horizontal position
with one end against the side of the ship and the other against the side
of a dry dock or dock to keep the vessel at a desired distance from the
face of the dock.
A principal member of the standing rigging, consisting of hemp or wire
ropes which extend from or near a masthead to the vessel's side, or to
the rim of a top, to afford lateral support for the mast.
Bay: A name applied to the space on board a ship where members of the
crew and passengers are given medical service and includes the
dispensary, operating room, wards, etc.
Plating: A term applied to the plating above the bilge in the main body
of a vessel. Also to the sides of deck houses, or to the vertical sides
of enclosed plated structures.
a Frame: The fore and aft dimension of a frame.
Hook: A hook made in halves and set on eyes facing each other in such a
manner that it may be made to function as a link.
The extreme after part of the keel of a vessel, the portion that
supports the rudder post and stern post.
The term usually applied to the outside planking or plating forming the
watertight envelope over the framework. It is also applied to the inner
bottom plating when it is called an inner skin.
Skylight: An erection built on a deck, having glass lights in its top
and fitted over an opening in the deck for the purpose of admitting
light and air to a compartment below.
The opposite of taut; not fully extended as applied to a rope; to "slack
away" means to payout a rope or cable by carefully releasing the tension
while still retaining control; to “slack off " means to ease up, or
lessen the degree of tautness.
Sleepers: Timbers placed upon the ground or on top of piling to support
the cribbing, keel, and bilge blocks.
A casing, usually of brass, fitted over line or other shafting for
protection against wear or corrosion, or as a bearing surface.
Ways: See launching.
length of chain or rope employed in handling weights with a crane or
davit. The rods, chains, or ropes attached near the bow and stern of a
small boat into which the davit or crane tackle is hooked. The chain or
rope supporting the yard at the masthead.
The difference between the pitch of a propeller, or the mean
circumference of a paddle wheel, and the advance of the ship through the
water corresponding to one revolution. An inclined launching berth. A
space between two piers for berthing a vessel.
The space in a shipyard where a foundation for launching ways and keel
blocks exists and which is occupied by a ship while under construction.
An opening in the lower part: of a bulkhead fitted with a sliding
watertight gate, or small door, having an operating rod extending to the
upper deck or decks. It is used to permit liquid in one compartment to
flow into the adjoining compartment.
Smokestack: A metal chimney or passage through which the smoke and
gases are led from the uptakes to the open air.
Snubbing: drawing in the waterlines and diagonals of a vessel abruptly
at their ends. The checking of a vessel's headway by means of an anchor
and a short cable. The checking of a line or cable from running out: by
taking a turn about a cleat, bitts, or similar fitting.
Patch: A temporary plate put on over a break or hole and secured with
tap bolts. It is made watertight with a gasket such as canvas saturated
in red lead.
Piece: The piece of steel or wood by which the sliding ways are bolted
to the ground ways at the upper end. See Launching.
Plate: A plate fitted to the top of a foundation to which the base of a
machine is bolted. Also a small plate fitted at the end of a stanchion.
Pipe: A vertical pipe in an oil or water tank, used to guide a sounding
device when measuring the depth of liquid in the tank. Also called a
The distance between any two similar members, as the span of the frames.
The length of a member between its supports, as the span of a girder. A
rope whose ends are both made fast some distance apart, the bight having
attached to it a topping lift, tackle, etc. A line connecting two davit
heads so that when one davit is turned the other follows.
A form of open-head wrench for use with special fittings whose character
is such as to preclude the use of the ordinary type wrench.
term applied to a pole serving as a mast, boom, gaff, yard, bowsprit,
etc. Spars are made of both steel and wood.
Frame: A single casting containing the bearings for and furnishing
support for the ends or the propeller shafts in a twin screw vessel. The
shell plating is worked outboard so as to enclose the shafts and is
attached at the after end to the spectacle frame. Used in place of shaft
stout metal pin headed on one end and pointed at the other, made of
either square or round bar, and used for securing heavy planks and
A method of uniting the ends of two ropes by first unlaying the strands,
then interweaving them so as to form a continuous rope.
Face: To finish off the surface around a bolt hole in a plane normal to
the axis of the hole to provide a neat seat for the nut or washer.
The deviation from a straight line or the amount of curvature of a sheer
line, deck line, beam camber, etc., an elastic body or device which
recovers its original shape when released after being distorted.
Squatting: The increase in draft assumed by a vessel when running over
that existing when she is at rest.
Stability: The tendency which a vessel has to return to the upright
position after the removal of an external force which inclined her away
from that position. To have stability, a vessel must be in a state of
Stability, Range of: The number of degrees through which a vessel rolls
or lists before losing stability.
floor or platform of planks supporting workmen during the construction
or the cleaning and painting of a vessel, located either inside or
outside the vessel.
Upright supports fastened together with horizontal and diagonal braces
forming supports for planks which form a working platform or stage.
To zigzag rivet holes in adjacent rows.
Stanchions: Short columns or supports for decks, hand rails, etc.
Stanchions are made of pipe, steel shapes, or rods, according to the
location and purpose they serve.
Rigging: Rigging that is permanently secured and that is not hauled
upon, as shrouds, stays, etc.
Stapling: Plates or angles fitted closely around or against continuous
members passing through a watertight or Oiltight member and calked or
welded to maintain the water or oil tightness of the structure.
Starboard: The right-hand side of the ship when looking from aft
forward. Opposite to port.
Stateroom: A private room or cabin for the accommodation of passengers
The ropes, whether hemp or wire, that support the lower masts, topmasts,
top-gallant masts, etc., in a fore and aft direction.
A strake of shell plating that does not extend completely to the bow or
Gear: A term applied to the steering wheels, leads, steering engine,
and fittings by which the rudder is turned.
The bow frame forming the apex of the intersection of the forward sides
of a ship. It is rigidly connected at its lower end to the keel.
The after end of a vessel; the farthest distant part from the bow.
Chock: A round or oval casting, or frame, inserted in the bulwark
plating at the stern of the vessel through which the mooring hawser or
warping lines are passed. Also called Stern Pipe.
Frame: A large casting or forging attached to the after end of the keel
to form the ship's stern. Includes rudder post, propeller post, and
aperture for the propeller in single-screw vessels.
Post: The main vertical post in the stern frame upon which the rudder
is hung. Also called the Rudder Post.
Tube: The bearing supporting the propeller shaft where it emerges from
the ship. It consists of a hollow cast-iron or steel cylinder fitted
with brass bushings, which in turn are lined with lignum vitae, white
metal, etc., bearing surfaces Upon which the propeller shaft, enclosed
in a sleeve, rotates.
Stiffness: The tendency of a vessel to remain in the upright position,
or a measure of the rapidity with which she returns to that position
after having been inclined from it by an external force.
Stiffener: An angle bar, T-bar, channel, etc., used to stiffen plating
of a bulkhead, etc.
A general term applied to the keel blocks, bilge blocks, and timbers
upon which a vessel is constructed.
Water: A term, applied to canvas and red lead, or other suitable
material placed between the faying surfaces of plates and shapes to stop
the passage of oil or water. Also applied to a wooden plug driven
through a scarp joint between timbers to insure water tightness.
The measure of the alteration of form which a solid body undergoes when
under the influence of a given stress.
An element of a rope, consisting, in a fiber rope, of a number of rope
yarns twisted together and, in a wire rope, of a primary assemblage of
A term applied to a continuous row of plates. The strakes of shell
plating are usually lettered, starting with A at the bottom row or
Bilge: A term applied to a strake of outside plating running in the way
of the bilge.
Bottom: Any strake of plating on the bottom, of a ship that lies
between the keel and the bilge strakes.
Member: Any plate or shape which contributes to the strength of the
vessel. Some members may be strength members when considering
longitudinal strength but not when considering transverse strength and
The intensity of the force which tends to alter the form of a solid
body; also the equal and opposite resistance offered by the body to a
change of form.
Stringer: A term applied to a fore-and-aft girder running along the
side of a ship and also to the outboard strake of plating on any deck.
The side pieces of a ladder or staircase into which the treads and
risers are fastened.
Plates: A term applied to the outboard plates on any deck, or to the
plates attached to the top flanges of a tier of beams at the side of a
heavy arm or brace.
Studding: The vertical timbers or framing of a wooden deck house,
fitted between the sill and the plate.
Box: A fitting designed to permit the free passage or revolution of a
rod or a pipe while controlling or preventing the passage by it of
water, steam, etc.
Superstructure: A structure built above the uppermost complete deck; a
pilot house, bridge, galley house, etc.
A term applied to, the oval or round opening in a chock or mooring ring.
Bulkheads: Longitudinal or transverse nontight bulkheads fitted in a
tank to decrease the swashing action of the liquid contents. Their
function is greatest when the tanks are partially filled. Without them
the unrestricted action of the liquid against the sides of the tank
would be severe. A plate serving this purpose is called a swash plate.
A special link constructed in two parts which revolve in each other,
used to prevent fouling due to turns or twists in chain, etc.
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Any combination of ropes and blocks that multiplies power. Also applied
to a single whip which does not multiply power but simply changes
Rail: The rail around the top of the bulwark or rail stanchions on the
after end of the weather deck, be it upper, main, raised, quarter, or
Shaft: The aft section of the shaft which receives the propeller.
Compartments for liquids or gases. They may be formed by the ship's
structure as double bottom tanks, peak tanks, deep tanks, etc., or may
be independent of the ship's structure and installed on special
Top: The plating laid on the bottom floors of a ship, which forms the
top side of the tank sections or double bottom; the inner bottom.
Tarpaulin: A canvas covering.
The condition of a rope, wire, or chain when under sufficient tension to
cause it to assume a straight line, or to prevent sagging to any
A rolled or extruded structural shape having a cross section shaped like
the letter T.
Telegraph: An apparatus, either electrical or mechanical, for
transmitting orders, as from a ship's bridge to the engine room,
steering gear room, or elsewhere about the ship.
A device for operating the valves of the steering engine from the pilot
house by means of either fluid pressure or electricity.
Template: A mold or pattern made to the exact size of a piece of work
that is to be laid out or formed, and on which such information as the
position of rivet holes, size of laps, etc., is indicated.
Head: The head or height of a column of water which will give a
prescribed pressure on the vertical or horizontal sides of a compartment
or tank in order to test its tightness or strength or both.
Tie-Plate: A single fore-and-aft or diagonal course of plating attached
to deck beams under a wood deck to give extra strength.
An arm attached to the rudder head for operating the rudder.
edge of a flange on a bar.
Pin: A pin having a shoulder and an eye worked on one end, called the
head, and whose other end, called the point, has its extremity hinged in
an unbalanced manner so that after being placed through a hole it forms
a T -shaped locking device to keep the pin from working out or being
withdrawn without first bringing the hinged portion into line with the
shaft of the pin.
Gross: The entire internal cubic capacity of a vessel expressed in
"tons" taken at 100 cubic feet each. The peculiarities of design and
construction of the various types of vessels and their parts necessitate
certain explanatory rulings in connection with this term.
Net: The internal cubic capacity of a vessel which remains after the
capacities of certain specified non-revenue spaces have been deducted
from the gross tonnage. Tonnage should not be confused with
Lift: A rope or chain extending from the head of a boom or gaff to a
mast, or to the vessel's structure, for the purpose of supporting the
weight of the boom or gaff and its loads, and permitting the gaff or
boom to be raised or lowered.,
That portion of the side of the hull which is above the designed
waterline. On or above the weather deck.
A seat or couch built at the side of a stateroom or cabin, having
lockers (transom lookers) or drawers underneath.
Transom Board: The board forming the stern of a square-ended row boat
or small yacht.
Frame: The last transverse Frame of a ship's structure. The cant
frames, usually normal to the round of the stern, connect to it.
Transverse: At right angles to the ship's fore-and-after center line.
Transverse Frames: Vertical athwartship members forming the ribs.
The steps or horizontal portions of a ladder or staircase upon which the
foot is placed.
Treenails: Wooden pins employed instead of nails or spikes to secure
the planking of a wooden vessel to the frames.
The difference between the drafts forward and aft. The angle of trim is
the angle between the plane of flotation and the mean water-line plane.
A vessel “trims by the head" or “trims by the stern" when the vessel
inclines forward or aft so that her plane of flotation is not coincident
with her mean water-line plane. See Drag.
Brackets: Flat bars or plates placed at various points on deck girders,
stiffeners, or beams as a reinforcement to prevent their free flanges
vertical or inclined shaft formed by bulkheads or casings, extending one
or more deck heights, around openings in the decks, through which access
can he obtained, cargo, stores, etc., handled, or ventilation provided
without disturbing or interfering with the contents or arrangements of
the adjoining spaces.
Home: The decreasing of a vessel's beam above the waterline as it
approaches the rail. Opposite of flare.
Turnbuckles: Used to pull objects together. A link into whose opposite
ends two threaded bars, one left-handed, the other right-handed are
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Umbrella: A metal shield in the form of a frustum of a cone, secured to
the outer casing of the smokestack over the air casing to keep out the
Deck: Generally applied to the uppermost continuous weather deck.
Works: Superstructures or deck erections located on or above the
weather deck. Sometimes applied to the entire structure above the
To remove anything from its accustomed or stowage place; to take apart.
A metal conduit connecting the boiler Combustion space with the base of
the smokestack. It conveys the smoke and hot gases from the boiler to
the stack and is usllal1y made with double walls, with an air space
between to prevent radiation of heat into adjacent spaces.
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Ropes secured to the outer end of a cargo boom, the lower ends being
fastened to tackles secured to the deck, used for guiding and swinging
and for holding the boom in a desired position. Also applied to ropes
secured to the after end of a gaff and led to each side of the vessel to
steady the gaff when the sail is not set.
Ventilation: The process of providing fresh air to the various spaces
and removing foul or heated air, gases, etc., from them. This may be
accomplished by natural, draft or by mechanical means.
Ventilators, Bell-Mouthed or Cowl: Terminals on open decks in the form
of a 90-degree elbow with enlarged or bell-shaped openings, so formed as
to obtain an increase of air supply when facing the wind and to increase
the velocity of air down the ventilation pipe.
small inclined awning running around the pilot house over the windows or
air ports to exclude the glare of the sun or to prevent rain or spray
from coming in the openings when the glazed frames are dropped or
opened. They may be of canvas or metal.
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light hawser or tow rope; to move a vessel by means of lines or warps
secured to some fixed object.
Plates: Plates fitted fore and aft between floors to check the rush of
bilge water from side to side when the ship is rolling.
Waterline: A term used to describe a line drawn parallel to the molded
base line and at a certain height above it, as the 10-foot waterline. It
represents a plane parallel to the surface of the water when the vessel
is floating on an even keel, i.e., without trim. In the body plan and
the sheer plan it is a straight line, but in the plan view of the lines
it shows the contour of the hull line at the given distance above the
base line. Used also to describe the line of intersection of the surface
of the water with the hull of the ship at any draft and any condition of
Watershed: A fitting on the outside of the shell of a ship over an air
port, a door, or a window to prevent water which runs down the ship's
side from entering the opening. One over an air port is also called a
Brow or Port Flange.
Watertight Compartment: A space or compartment within a ship having its
top, bottom, and sides constructed in such a manner as to prevent the
leakage of water into or from the space unless the compartment is
A narrow channel along the edge of the deck for the collection and
disposal of water occurring on the deck.
Bar: An angle or flat bar attached to a deck stringer plate fanning the
inboard boundary of a waterway and serving as an abutment for the wood
Deck: A term applied to the upper, awning, shade, or shelter deck, or
to the uppermost continuous deck, exclusive of forecastle, bridge, or
poop, that is exposed to the weather.
vertical portion of a beam; the athwartship portion of a frame; the
portion of a girder between the flanges.
Frame: A built-up frame to provide extra strength consisting of a web
plate with flanges all its edges placed several frame spaces apart, with
the smaller, regular frames in between.
Wood or metal pieces shaped in the form a sharp V, used for driving up
or for separating work. They are used in launching to raise the vessel
from the keel blocks and thus transfer the load to the cradle and the
term loosely applied to any tackle used for hoisting light weights and
serves to designate the use to which a tackle is put rather than to the
method of receiving the tackle.
A special type of drum whose faces are so fanned as to fit the links of
a chain of given size.
hoisting or pulling machine fitted with a horizontal single or double
drum. A small drum is generally fitted on one or both ends of the shaft
supporting the hoisting drum. These drums are called gypsies,
niggerheads, or winch heads. The hoisting drums either are fitted with a
friction brake or are directly keyed to the shaft. The driving power is
usually steam or electricity, but hand power is also used. A winch is
used principally for the purpose of handling, hoisting, and lowering
cargo from a dock or lighter to the hold of a ship and vice versa.
Windlass: An apparatus in which horizontal or vertical drums or gypsies
and wildcats are operated by means of a steam engine or motor for the
purpose of handling heavy anchor chains, hawsers, etc.
Scoop: A scoop-shaped fitting of sheet metal which is placed in an open
air port with the open side forward for the purpose of catching air and
forcing it into a cabin, stateroom, or compartment.
Winging: A term used to designate structural members, compartments,
sails, and objects on a ship that are located a considerable distance
off the fore-and-aft center line.
Filling the contlines of a rope with tarred small stuff preparatory to
serving, to give the rope a smoother surface and to aid in excluding
moisture from the interior of the rope.
Wrinkling: Slight corrugations or ridges and furrows in a flat plate
due to the action of compressive or shear forces.
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term applied to a spar attached at its middle portion to a mast and
running athwartship across a vessel as a support for a square sail,
signal halyards, lights; etc.
A term applied to the outer end of a yard.
frame or bar having its center portion bored and keyed or otherwise
constructed for attachment to the rudder stock. Steering leads to the
steering gear are connected to each end of the yoke for the purpose of
turning the rudder. Yoke lanyards are lines extending from the ends of
the yoke to the stern sheets of a small boat for use in steering.
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