Glossary of Nautical and Shipbuilding Terms
At right angles to the keel.
A hole through casing, bulkhead, floor or deck to enable one to reach
work or gear.
Stairs slung at the gangway.
Toward the stern or rear of ship. Between the stern and the amidship
section of a vessel.
That part from midship to the stern or rear.
The hatchway nearest the stern.
A compartment just forward of the stern post. It is generally almost
entirely below the load water line.
AFTER PEAK BULKHEAD
The bulkhead at the stern next to the after peak; always watertight.
A vertical line at right angles to the base line at a point
designated by the naval architect.
A ring-shaped plate coaming surrounding the stack and fitted at the
upper deck, just below the umbrella. It protects the deck structure from
heat and helps ventilate the fire room.
An opening in the vessel's side or deck house for ventilation.
Above the deck.
In the longitudinal, or fore and aft center of a ship. Halfway
between stem and stern (front and rear).
An iron implement for holding a ship at rest in the water by means of
a fluke or hook which grips the bottom. (From the Greek word for hook.)
The point where two lines meet. Sometimes used as a shorter term for
A bar "L" shaped, or two flanges at 90 degrees.
A piece of angle iron used to fasten one part of a ship's structure
Circular angular section fastened around a column to hold the column
to the deck.
A small plate on forecastle deck to cover stem, sometimes used to
support a chock.
To collect or put into place different parts.
Across, from side to side; transverse; at right angles to the keel.
At right angles to the keel. Same as abeam.
The supports for pumps, condensers, distillers, etc.
Tanks carried in various parts of a ship for water ballast, to keep
the vessel on an even keel.
A horizontal level line at the lowest point of the mold lines and the
top of the keel plate.
A narrow strip of wood for fairing lines. Also a strip of wood to
fasten objects together.
The extreme width of a ship. Also a transverse horizontal member
supporting a deck.
A structure fitted for support of the feet of the engine columns, as
well as to provide support for crankshaft bearings. It also helps
distribute engine weight and stresses to the ship's structure. The bed
plate consists of a series of transverse girders, connecting fore and
aft members of girders.
A half hour period of a watch on board ship.
|Number of |
(am or pm)
The rounded portion of a vessel's shell that connects the bottom
with the sides.
A fin fitted on the bottom of a ship at the bilge to reduce rolling.
It commonly consists of a plate running fore and aft 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.
Any plate in a bilge strake.
Iron heads fixed on any deck, for belaying of hawsers, warps, ropes,
Originally spelled "bittacle." A bin or cupboard in which was stored a compass,
log board, a lamp at night, and other navigation gear.
Frames fitted upon deck conforming to the shape of the bottom of the
boat which is bedded in it.
BOATSWAIN or BO'SUN
The Bo'sun was the officer in charge of rigging, sails and sailing equipment.
Ships were usually commanded by boatswain in the eleventh century.
From the Saxon word "swein" meaning boy or servant.
The Bo'suns Call or Whistle was once the only method, other than
human voice, of passing orders to men on board ship. Since a shouted
order may not have been heard above the wind and seas during storms, the
instructions to hoist sails, haul or let go ropes, etc were conveyed by
different notes and pitches on the high-pithced whistle. First used on
English ships in the thirteenth century, the whistle became known as the
"Call" about 1630 when the Lord High Admiral of the Royal Navy wore a
gold whistle as a badge of rank.
A plan consisting of two half transverse elevations or enll 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, bow and buttock
lines and the diagonal lines.
A wall protecting the different deck spaces from the heat of the
That part of the ship where the boilers are placed, connected with
boiler hatch to top deck.
A piece of plate adjoining the hawse hole, to prevent the chafing of
the hawser against the cheeks of a ship's bow. A plate for support like
a pillow or cushion.
The cover of a scuttle-way or small hatchway such as that which leads
to the forecastle or fore peak.
A boom extending from the mast like a derrick arm, to handle cargo.
A saddle in which the boom is lashed down and made fast.
A platform built up of channels, plates, and angles around both masts
about on a level with the bridge. The cargo booms swivel on this table.
The inside of an angle bar.
An angle bar of sufficient length to connect the ends of two angle
bars, usually three rivet holes on each side, fitting in the bosom or
inside of the angles.
Any protuberance on parts. For example: The boss on the stern casting
is the part that the propeller shaft runs through.
A frame bent to allow room for the stern tube, or tail shafts in the
case of twin-screwships.
A curved plate covering (one on each side) the boss of a propeller
post and the curved portion of frames in way of the stern tube of a
screw steamer. This plate is of extra thickness.
That part of the shell plating which is below the water line.
An angle which surrounds a plate in a frame or a bulkhead to make
connections. A shape binding or connecting two plates.
The front or forward end of a ship.
Any of the shell plates in the bow of a ship.
A steel plate, commonly with a reinforcing flange, used to stiffen or
tie beam angles to bulkheads, frames to longitudinals, etc.
The side to side measurement of a vessel at any given place. The ends
of the cross beams are considered the outward breadth measurements.
The width of a skip, including the thickness of plates.
Measured amidships at its greatest breadth to outside of frames.
Measured amidships at its greatest breadth to outside plating.
The beam in the poop and forecastle decks, the beams nearest the
amidships from the decks.
A triangular shaped plate fitted between decks connecting panting
stringers in the bow for the purpose of rigidly fastening the stem and
A partial deck extending from side to side of a vessel amidships.
It is common in steam vessels, affording a convenient station for the
officer in command. It is also known on British ships as the hurricane
or bridge deck.
The erection or superstructure fitted about amidship on the upper
deck of a ship. The officer's quarters, staterooms and accommodations
are usually in the bridge house.
BRIDGE, LONG OR CAT WALK
On tankers, a narrow walk connecting forward deck house to after
deck house. On large passenger ships, a bridge having considerable
length fore and aft.
A small curved angle or flanged plate fitted on the outside of the
shell of a ship over an air port to prevent water running down the
ship's side from entering the open port.
BROW OR BROW PLATE
A plate forming a riser on the port and starboard and fore and aft
sides of 'tween deck hatches. It makes possible trucking cargo up on the
'tween deck hatch cover so that it can be hoisted through the shelter
deck cargo hatch.
A plate warped in or out, making it out of line; a plate thicker at
the center than at the edges.
An angle bar with its long leg terminating in a bulbed toe.
A watertight partition extending from the double bottom to the top
main deck, ao constructed that in case of accident in one compartment,
damage is confined to that compartment. A partition in a ship which
divides the interior into various compartments.
The bulkhead farthest forward, generally called the collision
A partition wall of plating running in a fore and aft direction.
A partition wall of plating running in an athwartship direction
across a portion of the whole breadth of a ship.
A term applied to the strake of shell plat ing above a weather or
shelter deck. It helps to keep the deck dry and also serves as a guard
against losing cargo or men overboard.
A boat selling supplies, provisions and articles to ships.
Derived from "boomboat" meaning boats permited to lie at booms.
A compartment in which fuel is stored.
Floating beacons which by shape and color give the mariner valuable navigational information.
The capacity for floating which a vessel possesses.
A joint made by fitting two pieces squarely together on their edges,
which is then welded or butt strapped.
The traces formed by the intersection of longitudinal vertical planes
parallel to the central longitudinal vertical plane of the ship, with
the forward and after surface of the ship's hull, these traces when
occurring in the fore body are called bow lines and when in the after
body buttock lines. However, the term buttocks is often used to denote
both bow and buttock lines.
A plate to connect two plates or bars together at the ends.
To tighten a lap or other seam with a chisel.
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. In
brief, the camber is the crown or arch of a weather deck.
A term signifying an inclination of an object from a perpendicular;
to turn anything so that it does not stand perpendicularly or square to
Any of the beams supporting the deck plating or planking in the
overhanging part of the stern of a vessel. They radiate in fan shape
from the transom beam to cant frames.
The frames (generally bulb angles) at the end of a ship which are canted;
that is, which rise obliquely from the keel.
From the Saxon titles "caput" the head or chief and "thane."
From the Latin "carga" meaning a load.
An opening in a ship's deck for the loading and discharging of any kind of cargo.
A large opening in a vessel's side through which cargo is passed on and off.
The extra case or bulkhead built around the ship's funnel, engine room or
boiler room to protect the surrounding parts from heat.
The fore and aft line at the middle of the ship.
CENTER LINE BULKHEAD
A bulkhead running from the forepeak or collision bulkhead to the
afterpeak bulkhead, except in the engine space. The neutral center of
the center line bulkhead is on the center line of the ship.
The compartment, near and below the hawse holes at the bow, for stowing the anchor chains.
A pipe of large diameter, through which the chains pass into the chain lockers.
A small line, strong enough to with stand being drawn very taut over
a surface. The line is first chalked, then drawn taut between two points
and "snapped," thus leaving an impression of the chalk on the surface to
The Gally smokestack.
From the Latin "charta", a kind of papyrus.
Used in shaping plates, etc., to make sure that the templates have not
changed in size by shrinking, expanding or warping.
Deck fittings for mooring line to pass through.
A piece of wood used to belay ropes.
Short length of bar, generally an angle, used to attach shapes to the
A frame bounding a hatch for the purpose of stiffening the edges of
the opening and forming the support for the cover. It also prevents any
water on deck from washing down to the deck below through the
Plates, heavier than bulkhead plates, at the top and bottom of deck
house, bulkheads, and division bulkheads between decks, for the purpose
of stiffening and adjusting height to suit the shape of the ship.
A void or empty space separating two or more compartments for the
purpose of insulation, or to prevent the liquid contents of one
compartment from entering another in case of a leak.
An angle ring used around a pipe or mast, or a flat plate made to fit
around a girder or beam passing through a bulkhead or deck. It serves to
make various spaces watertight, oiltight, weathertight, or dusttight.
A watertight bulkhead at the forepeak extending to main deck. This
bulkhead prevents the entire ship from being flooded in case of a
A pillar or stanchion.
A set of steps or ladder leading up to deck from below.
The overhang of the stern aft of the stern post.
A hole tapered so that a rivet, bolt, or screw head will come flush
with the surface of the material.
Frames used during construction of a ship conforming to the curvature
and shape. They are generally made of flat bars and shapes and support
the shell until the shell is tied in the bulkheads and framing.
From the Norman word "acrue" meaning to increase.
Timbers used to support bottom of ship while it is under
A structure on the mast built up of plates and angles for the purpose
of holding the shroud pads.
A platform and protective coaming setting on the crosstree on the
foremast, to accommodate the look-out aloft while the ship is at sea.
A crane that projects over the side of a ship or hatch. A set of cranes
or radial arms on the gunwale of a ship, from which are suspended the lifeboats.
The midship portion of a vessel throughout the length of which a
constant shape of cross-section is maintained.
Heavy glass in portholes; also heavy glass sometimes placed in decks.
The angle which the straight portion of the bottom floor of the
midship section makes with the base line. It is expressed by the number
of inches rise above the base line in the half-breadth of the vessel.
A reckoning kept so as to give the theoretical position of a ship without
aid of objects on land, of sights, etc. It consists of plotting on a chart the
distance believed to have been covered, and the course steered.
From deduced reckoning, abbreviated first to "ded reckoning."
A hoisting apparatus consisting of a tackle rigged at the end of a beam.
From the name of Thomas Derrick, a 17th century English hangman who
devised a spar with a topping lift and purchase instead of the old-
fashioned rope method.
A deck in a ship corresponds to the floor in a building. Decks are
named or numbered by the naval architect designing the ship and bear
these names and numbers from that time on.
A beam which supports a deck.
DECK BEAM STRINGER PLATE,
DECK STRINGER PLATE,
DECK BEAM STRINGER
A plate stringer placed on the beam ends of any deck, the stringers
take their names from the beams of the various decks on which they are
A partial deck extending from side to side of ship about amidships.
A partial deck at bow of ship, raised above weather deck.
Continuous longitudinals fastened under the deck.
A small house erected upon the deck of a ship for any purpose.
DECK-HURRICANE OR BOAT DECK
The uppermost deck; deck where boats are stowed.
The line from forward to aft where a deck touches the ship's side.
DECK-LOWER OR ORLOP DECK
The first deck above tank top.
The deck at the top of the main body frames. Above the main deck the
frames are smaller and lighter in weight.
A pillar fitted to support a deck.
A drawing showing the layout of a deck.
Plates covering deck beams and thus forming an iron steel deck.
The raised deck on the after part of a ship.
A deck above upper deck, set aside for use of first-class passengers
on passenger ships.
DECK STRINGER ANGLE BAR OR GUNWALE BAR
An angle bar used to secure stringer plate of any deck to shell
See deck beams.
Floors in the fore and aft ends of a vessel, so called on account of
their greater depth.
These usually consist of ordinary hold compartments but strengthened
to carry water ballast. They are placed at either or both ends of the
engine and boiler space. They usually run from the tank top up to or
above the lower deck.
DEEP WATER LINE
The line to which a vessel is submerged with a full cargo on board.
Measured amidships from the top of keel to the top of beam at the
Total weight of ship while afloat, including everything aboard.
The result of excessive strains that cause a plate or a form to lose
its proper shape.
Holding devices used on doors, hatch covers, air ports and other
hinged parts of a ship.
An auxiliary engine to operate the lifting apparatus on deck.
A tank whose bottom is formed by the bottom plates of a ship, used to
hold water for ballast, for the storage of oil, etc.
An extra plate of the same strength or stronger than the original
plating secured to the original plating for additional strength.
The stern and stem are marked in feet to show the draught or depth of
A small tool used to draw adjoining parts in line so that the rivet
holes will coincide.
A dock into which a vessel is floated, which when raised lifts the
boat out of the water.
Where the engines of a ship are confined, next to the boilers.
Ensign Bearer, shortened to Ensign, was the rank of a young officer
in the early French Army. Adopted by the United States Navy in 1862.
From the old Norman "enseigne" for "flag."
The process of hoisting into place and bolting up the various parts
of the ship's hull, machinery fittings, etc.
To shape, assemble, and secure in place the component parts in order
to form a complete whole. To manufacture.
FAIRING A LINE
Straightening lines supposed to be straight or smoothing out into a
smooth curve, lines supposed to be curved.
A term applied to fittings or devices used in preserving the
direction of a rope, chain or wire, so that it may be delivered fairly
or on a straight lead to the sheave or drum, etc.
A term applied to plating fitted in the shape of a frustrum of a
cone, around the ends of shaft tubes and struts to prevent an abrupt
change in the stream lines. Also found at ends of heavy steel armor.
The upper and round part of the stern. The frames or cants are
arranged like the tail of the famous breed of pigeons, fantail.
A marine unit for measuring depth. Today one fathom equals six feet.
From the Anglo-Saxon "faehom" for the act of stretching two arms wide
as a rough measurement of six feet.
A partially raised deck over the engine and boiler rooms, always around the smokestack.
Where two surfaces meet, forming a corner, any material in the corner to
partially fill it is a fillet. Usually the fillet is concave.
The turned edge of a shape or plate, which acts to resist bending strain.
The spreading out from the central vertical plans of the fore-body of
a ship with increasing rapidity as the section rises from the water line
to the rail.
A term applied to a partial deck built without any camber.
The bottom center line plate of the ship.
A plate placed vertically in the bottom of a ship on every frame and
running athwartship, from bilge to bilge.
A deck whose top side is flush.
FLUSH HEAD RIVET
A rivet, the head of which does not extend above the surface of the
plate, angle bar, etc., in which it is driven.
FORE AND AFT
In line with the ship's keel; fore and aft deck line girders.
That part from the amidships to the front of stem.
FORECASTLE or FOCSLE
Crew's quarters on the forward part of the ship generally below the
main deck on cargo ships and above the main deck in tankers.
The word forecastle or foc'sle has survived from the 12th century,
when the Norman ships had castles of wood placed fore and aft on the
decks to fight from.
Toward the stem or front. Between the stem and amidships.
The narrow extremity of a vessel's bow. Also the hold space within it.
The forward part of the bow which overhangs the keel.
A vertical line perpendicular to the base line at a point designated
by the naval architect. Usually frames start numbering from the forward
perpendicular, which is the zero frame.
FOUNDATION PLATE, SOLE PLATE
A plate to which an engine or pump, etc., is bolted. A plate forming
part of a foundation.
FRAME ANGLE BARS
The angle bars of which a frame of any kind is constructed.
The section of a frame that rises above the deck line.
Lines of a vessel as laid out on the mold loft floor, showing the
form and position of the frames.
A template for the frame of a ship.
The ribs of a ship.
A group of frames (cant frames) extending over the rudder forming the
stern of the ship; frames not at right angles to the keel.
The distance between frames.
Angles at top of floor plates; angle forming part of a frame, but in
a reversed position to the angle joining the shell plating.
Frames in the side above and connecting with the margin plates.
The distance from the water line to top of bulwark, amidships.
An opening in the bulwark or rail for discharging large quantities of
water, when thrown by the sea upon the ship's deck. Some ships have what
are called "swing gates" that allow water to drain off but which
automatically close from the pressure of sea water.
A large sheet iron tube, extending from the uptake high above the
deck, through which the smoke and gases pass.
A plate that requires heating in order to shape it as required.
Any little handy contraption such as a scraper or special sailmaker's
The kitchen of a vessel.
The process of coating one metal with another, ordinarily applied to
the coating of iron or steel with zinc. The chief purpose of galvanizing
is to prevent corrosion.
A board with cleats, forming a bridge reaching from a gangway of a
vessel to the wharf.
The opening in the bulwarks of a vessel through which persons come on
board or disembark. Also a gangplank.
The plating next to the flat keel, or what is known as strake A.
GEAR - (STEERING GEAR, RUNNING GEAR, CLEANING GEAR, ETC.)
A comprehensive term used in speaking of all the implements,
apparatus, machinery, etc., that are used in any given operation.
A metal fitting that holds a member in place, or presses two members
A heavy supporting beam.
The measurement around the body of a ship The half girth is taken
from the center line of the keel to the upper deck beam end.
A return, or 180 degree bend, having one leg shorter than the other.
An iron swivel making up the fastening between a boom and a mast. It
consists of a pin and an eyebolt, or clamp.
An open iron lattice work used for covering hatchways and for forming
a platform in engine room, stair landings, etc.
The sharp forward end of the dished keel on which the rudder is hung.
A ring of candle wicking used as a washer or gasket around bolts and
studs to make a watertight joint.
Stationary timbers, or tracks, laid on the ground or foundation
cribbing, upon which the sliding bmbers or ways (supporting a vessel to
be launched) travel.
A metallic eye cast on the stern post, on which the rudder is hung.
The line where a shelter deck stringer meets the shell. Pronounced
An angle on the deck connecting both deck and shell.
A tie plate, used for fastening posts frames, beams, etc., to other
The gutter or runway between the gunwale and gutter angle bars,
forming a channel for water to run to deck scuppers.
Wire or hemp rope or chains to support booms, masts, davits, etc.;
guys are employed in pairs. Where a span is fitted between two booms,
for example, one pair only is required for the two.
Short beams extending from a machinery or boiler casing or from the
hatch side coaming to the side of the ship.
A plan of one-half of a vessel, divided by a center line drawn
through the stem and stern posts. It shows the water, bow, and buttock
The bars by which the hatches are fastened down.
Thin strips of wood or steel fitted tight against the coamings to hold the
hatch covering or tarpaulin in place.
Covers for closing up hatchways.
HATCH STRONG BACK
A member built up of plates and angles to provide a support for the
One of the large square openings in the deck of a ship through which
freight is hoisted in or out, and access is had to the hold. There are
four pieces in the frame of a hatchway. The fore and aft pieces are
called coamings and those athwartship are called head ledges. The head
ledges rest on the beams and the carlings extending between the beams.
There may be forward, main and after hatchways, according to the size
and character of the vessel.
Vertical plates forming the border around a hatchway.
That part of a ship's bow in which are the hawse holes for the
anchor chains. From an old English name for throat.
A hole in the bow through which a cable or chain passes. It is a cast
steel tube, having rounded projecting lips both inside and out.
A cast steel pipe connected to the hawse hole running from the shell
to the deck, for chains to pass through.
HAWSE PLUG OR BLOCK
A stopper used to prevent water from entering the hawse hole in heavy
A cable used in warping and mooring.
A bar or angle under a deck the same size as deck beams. It is used
around stair openings in deck, small hatch openings, or at dead end of
The intersecting point or corner of the web and flange of a bar.
The rudder, steering wheel and tiller.
An interior part of a ship, in which the cargo is stored. The various
main compartments are distinguished as the forward, main, and after
holds, or by numbers such as 1, 2, 3, 4, etc.
A dog or brace to hold objects rigidly in place.
See Tumble Home.
Setting the frames of a vessel square to the keel after the proper
inclination to the vertical due to the declivity of the keel has been
The body of a vessel, not including its masting, rigging, etc.
Steel beams with cross section like the letter "I."
Those on board ship who from being liable to constant day watch are not subject to night watch.
From the side to the center of ship.
The top of a double bottom. Tho tank top.
INNER STRINGER BAR
Any angle bar or flat bar on the inner part of a stringer plate.
A strake the edges of which are overlapped by those of the outside strakes.
Plates which fit between floors, frames, or beams, as stiffeners.
Beams placed between deck beams, if the spacing of the latter is
Those frames in a cellular double bottom to which no floor plates are
A ladder with wooden steps and side ropes.
A rope ladder with wooden rounds.
To lap a joint by keeping one edge straight and bending the other in
order to leave both surfaces even on one side. An offset in a plate, the
depth of which is equal to the thickness of the plate forming the lap
and that is not offset.
The "backbone" of a ship. A series of connected plates running fore
and aft on the bottom of the center line of the ship.
Blocks on which the keel of a vessel rests when being built, or when
she is in dry dock.
A vertical strake of plates on the keel at the center line, running
fore and aft from stem to stern. It is sometimes called the center line
girder or center keelson.
The main pillar posts of the ship. Also called samson post. A post or
pillar forming support for a cargo boom.
An angle or channel from deck beam to shell frame taking the place of
A unit for measuring speed. To appreciate the term "knot" consider the following:
If a ship goes one nautical mile in one hour, how far does she go in a half minute?
Having found this distance (which is about eight fathoms), mark this
distance in knots on the log line for as many spaces as deemed necessary.
Now, when the log is hove, the number of knots that will pass
off the reel while the half minute sand glass is running will correspond
to the number of nautical miles the ship will go in one hour.
This why "she goes 10 knots" is right, and "she goes 10 knots an hour" is wrong.
Note: Since the nautical mile measures 6080 feet against the 5280 feet
in the land mile, there is a difference in the speed of a ship in "knots"
and the speed of an automobile in "miles per hour" (eg. 10 knots = 11.5 mph)
An abrupt change in direction of plating, frames, keel, deck, tank
top, and other structures of a vessel Most frequently used with
reference to the line at the apex of the angle dividing the upper and
lower part of the stern or counter. See knuckle line.
A line around the stern of a ship, on the cant frames, which divides
the upper and lower parts of the stern. Also an abrupt turn in any
plate, bulkhead, tank top, or deck. The line where a flanged bracket is
pressed is also called a knuckle line.
Inclined or vertical steps on board ship taking the place of
The distance from the edge of a plate or bar to the center of the
first rivet hole.
Tread on stairs enlarged to form a platform.
A joint in which one part of a plate overlaps another, thus avoiding
the use of a butt strap.
To place a vessel in the water, after completion.
Marking plates, bars or shapes for shearing, punching, bending, and
identification from a template or print.
To develop on a working surface, lines to their true dimensions.
LENGTH BETWEEN PERPENDICULARS (L.B.P.)
Measured from the forward perpendicular to the after perpendicular.
LIFT A TEMPLATE
To construct a template to the same size and shape as the part of the
ship to be duplicated.
LIFT FROM THE HULL
As a rule, templates are made for most plates and bars, but sometimes
it is necessary to "lift" by placing a frame of wood around the opening
for the missing plate, and when nailed, to transfer the holes of the
adjoining plates by pencil mark, and when a sufficient amount of landing
has been given, the plate should be the proper size.
Transferring marks, shapes, and measurements from a ship drawing, or
model, to a plate or other object, by means of templates.
A hole cut in a plate to make it lighter and yet not reduce its
strength. Sometimes large enough to be called a manhole.
LIGHT LOAD LINE
The water line when the ship rides empty.
An opening in a ship's side, provided with a glazed lid or cover for
the admission of light.
Holes in the bottoms of floors for drainage, or at the top of floors
for gas to escape.
A piece of flat steel which may or may not taper to a feather edge.
Used to fill out a lap or to form a middle layer between two objects.
Also for leveling foundations.
If one side of a vessel lies deeper in the water than the opposite
side, caused by the shifting of cargo, etc., it is said to list.
LENGTH OVER ALL (L.O.A.)
Measured from the most forward part of the fore end to the most
after part of the after end of the hull.
LOAD WATER LINE (L.W.L.)
A line painted on the side of the vessel to which the vessel sinks
when carrying its full load. The water line when a vessel is carrying
its full load.
A storage compartment in a ship.
See mold loft.
A man who lays out the ship's lines in the mold loft and makes the
molds and templates.
A bulkhead, frame, or longitudinal stiffener, running fore and aft.
LOWER DECK or ORLOP DECK
The deck next above the tank top.
MAIN BEAM - LONGITUDINAL
The two largest beams supporting a deck between which are cargo
MAIN BEAM - TRANSVERSE
Large beams at hatch ends, same size as longitudinal main beams.
The hull proper, without deck-house, etc.
MAIN BODY FRAMES - MAIN FRAMES
Frames below the main deck of a vessel.
MAIN BREADTH LINE
The greatest width of a ship. If a ship's sides tumble home, the main
breath line will be at the point where the tumble home begins.
The principal strength deck in a ship, atop the heaviest or main
MAIN DECK STRINGER INNER ANGLE BAR OR WATERWAY BAR
An angle bar forming inner side of watenvay.
MAIN DECK STRINGER OUTER ANGLE BAR OR GUNWALE BAR
An angle bar connecting main deck stringer to shell plating.
A hole in a tank, boiler or compartment on a ship, designed to allow
the passage of a man for examination, cleaning, and repairs.
A tank top plate carrying a knuckle.
A hollow steel pipe or tube made up of plates and doublers tapering
smaller at the top, placed on the center line of the ship.
A dining room on a ship.
The vertical transverse section located at the mid point between the
forward and after perpendiculars. Usually this is the largest section of
the ship in area.
The ordinary unit for measuring distance.
There are two different types of mile, the nautical and the statute.
The nautical mile is 6080.2 feet and is used by navigators to measure
distance at sea and in the air. For all practical purposes, 1 minute of
latitude equals 1 nautical mile.
The statute mile is 5280 feet and is used to measure distances on land.
1 nautical mile = 1.15 statute miles.
1 statute mile = 0.87 nautical miles.
To match angles; an angled cut made for a joint.
A pattern or template. Also a shape of metal or wood over or in which
an object may be hammered or pressed to fit.
The extreme height of a vessel amidships, from the top of the keel to
the top of the shelter deck.
A working point, used to guide the structural alignment in accordance
with the design.
The large enclosed floor where the lines of a vessel are laid out and
the molds or templates made.
Securing a vessel in position by cables or lines.
Cables or hawse lines used to tie up a ship.
A round or oval opening in the bulwark framed with a cast iron rim or
collar used for passing the mooring ropes, cables, etc., through
A short cast iron tube having a movable iron rod passing through its
center. On top of the rod is fixed a round metal cup, which may be
lifted to admit air or closed to prevent water entering tube, usually
fitted over cabins.
The 60th part of an equatorial degree, equal to about 6,080 English
feet; therefore 6 nautical miles represent 7 English miles,
One who designs ships.
The science of designing vessels.
The bridge used for taking observations, or directing the handling of
The plane which is the geometrical center of the thickness of a
A junction plate for the stem ends of port and starboard strakes
above the top of the stem casting.
A material made of tarred rope fibers, used for calking seams in a
To bend out of line sharply. The points given by the draftsman to the
loftsman for putting down lines.
Packed and calked to prevent flow or waste of oil.
On or in a ship.
The lowermost deck in a ship having four decks, or lower deck. See
Used to designate from the center to the sides of a ship.
A plan representing the longitudinal exterior of a vessel, showing a
side of the shell, all deck erections, masts, yards, rigging, rails, etc.
That portion of the shell plating of a vessel forming the bottom.
The outside plating of a vessel.
See shell plating.
OUTSIDE STRAKE, OVERLAPPING STRAKE
A strake of plating which overlaps inside strakes with its upper and
OVERHANG OR COUNTER
The amount of a ship's hull projecting above and beyond a
perpendicular from the water line at stem or stern.
OVERLAP OF PLATING
That portion of a strake of shell plating, etc., covering that of
The name of a plate that fits in the curve at the meeting of the
shell and the stern post at the counter.
The pulsation in and out of the bow and stern plating as the ship
alternately rises and plunges deep into the uater.
A horizontal stiffener with a breast hook giving added strength
A water plane with a protecting wing placed on bottom forward end of
the keel stem. An airplane shaped device swung overboard on end of a
cable off mine sweepers, to cut cables.
Tanks in the forward and after ends of a vessel. The principal use of
peak tanks is in trimming the ship. Their ballast is varied to meet
required changes in trim. Should the after hold be empty, the vessel
would ride so high that the propeller would lie half out of water and
lose much of its efficiency. Filling the after peak tank forces the
propeller deeper into the water.
Any steel bar or column, fitted vertically, to support a deck, or any
part of a ship's structure. Also called a stanchion.
A tapered metal pin which fastens the rudder to the stern post and
affords an axis of oscillation as the rudder is moved from side to side
The distance between the center of two contiguous objects, such as
teeth of a wheel, etc.; also the distance a screw propeller would
advance in one revolution, if turning in a steadfast medium.
A flat working surface for layout and assembly work.
Plates fitted diagonally.
Plating joined horizontally, forming an elevated stand or flooring.
Flat steel stock of various thicknesses.
The difference between the diameter of a shaft rod, etc., and that of
the hole in which it works.
The mark stencilled in and painted on a ship's side, designated by a
circle and horizontal lines to mark the highest permissible load water
lines under different conditions.
Welded up oblong holes in a plate that leps on another plate or
A portable tank used to give buoyancy.
The structure or raised deck at the after end.
A bulkhead placed at the fore end of a poop between the shelter deck
and the poop deck.
POOP DECK BEAMS
The beams on which a poop deck is laid.
POOP DECK WATERWAY
The space between the gunwale and the gutter angle bars on a poop.
A ladder leading from a shelter deck to a poop deck.
A rail surrounding the poop deck.
An opening in a vessel's side, in a bulwark, etc., used for various
A flange protruding above a port to keep drip from entering.
An opening in the ship's shell plating.
A shutter for closing a port hole in stormy weather.
The left-hand side of the ship looking forward, toward the bow or
Strong bulkheads placed across the hold to prevent the cargo from
shifting in vessels that are laden in bulk.
A small punch with a keen point used to transfer the holes from the
template to the plate.
The side elevation of a ship's form.
A limited test applied to anchors, chains, etc., to prove the
trustworthiness of the material from which they were manufactured.
The means by which a vessel is driven through the water.
The arched section of the hull above the propeller.
PROPELLER BLADE FLANGE
A flange on blades that are bolted to propeller boss.
The flat arms that take hold on the water as propeller turns.
The hub to which removable blades are bolted.
A propeller so called because blades are at an angle to line of axis,
similar to the thread of a screw.
PROPELLER SHAFT, TAIL SHAFT
The shaft to which the propeller is keyed or fastened.
The part of the bow extending from the load water line to the top of
PUNCHED RIVET HOLE
A rivet made by a punching machine.
A nautical instrument, on the arc of which is a finely graduated
scale showing degrees and minutes, with adjustable reflectors, etc.;
used to find the altitude of heavenly bodies, angular distances, etc.;
on a marine engine, quadrant bars are part of the reversing gear. On a
steering gear, the rudder quadrant is a section of a wheel or sheave
fastened to the rudder head.
The riveting together of parts by four rows of rivets.
An officer having charge of a subdivision of workmen in a navy yard.
An able seaman, almost exclusively employed for steering a vessel; on
large steamers four to six men so rated relieve each other every hour or
two. A petty officer in the navy.
QUARTERS (OF A SHIP)
Living space for the crew.
To shorten the radius of a curve; as, to quicken a sheer is to make
it more pronounced.
An edge having material removed to accommodate other material to be
applied on that edge.
A shelf, framework, etc., in which objects are secured to prevent
them from moving about.
A guard made of flat pieces of wood, or steel bars or rods, joined,
and connected to the upper edge of the bulwark plating, or fitted upon
the summits of stanchions surrounding an upper deck, bridge, poop, or
The iron stanchions, about three feet high, placed about the same
distance apart, fitted with several tiers of guard ropes or chains, to
enclose the sides and ends of a bridge, forecastle or poop, and
sometimes an upper deck.
RAISED QUARTER DECK
A structure interrupting the after portion of a shelter deck, raised
several feet above it, extending from side to side of a vessel.
The inclination of a vessel's mast, funnel, stem, etc., from its
upright angle with the keel. The rake may be either forward or aft. The
elevation of the out end of a bowsprit above the level of its inner end.
Using a reamer to make rivet holes fair and smooth on the inside.
A bulkhead of any recessed portion of a hold or compartment.
RECESS OF TUNNEL
The elevated and extended portion of a tunnel. At the after end such
an enlargement of tunnel is called "stuffing box recess," while at the
forward end it is known as "thrust recess."
The gears that reduce turbire speed to propeller speed. They
constitute an important part of a turbine installation and may be
located forward or aft of the turbines. The reduction is generally made
in two stages.
RESERVE BUOYANCY (OF A VESSEL)
The lifting power. It may be measured by the volume of watertight
hull above the load water line.
An angle bar with its heel against another angle to give the other
angle additional strength.
Strips of material temporarily holding parts of a ship in position.
Any frame riveted or welded on another frame for the purpose of
Plates set on top of the center keelson. The strake of plates at the
center line of each deck.
One whose occupation is to rig or unrig vessels, take up or down the
Manila and wire ropes, lashings, etc., used to support booms, masts,
spars, etc. Also, handling ana placing heavy weights and machinery.
A vertical plate between steps in a stairway.
A metal pin by which the plating and other parts of iron and steel
vessels are joined. Rivets are known by their heads, such as: Flush,
pan, snap, plug, tap, countersunk, mushroom, and swollen neck.
The punched or drilled holes in plating. frames, etc., into which the
rivets are driven for connection.
To fasten with rivets.
Chocks with a short vertical roller fixed to ease a line passing
ROW OF RIVETS
A continuous line of rivets.
A swinging vane, built up of casting and plates, hung to the stern
post of a ship, by which the ship is steered.
"L" shaped casting flanged to rudder stock forming an arm to control
A rudder placed at the bottom of the forward stem and maneuvered from
the fore peak.
The flange which ties the main part of the rudder to the rudder trunk.
A small rudder fastened to the after part of the regular rudder which
by hydraulic action pulls the main rudder to either side.
RUDDER POST OR RUDDER STOCK
That portion of the rudder casting bearing the gudgeon eyes or "hinge
ears" and rudder flange.
RUDDER TRUNK TUBE
A cylinder made up of plates which enclose the rudder trunk or stock.
The narrowing of a vessel's after bottom.
When from some cause a vessel's form is so altered that the ends of
the keel are much above the level of its midship portion, it is said to
SCARF or SCARPH
A lapped joint made by beveling off, or otherwise cutting away the
sides of two plates at the ends.
An arrangement to prevent the cold air from striking the boilers
The thicker central portion of a screw propeller, to which movable
blades are attached by studs and nuts.
A propeller having blades or paddles set at an angle and having a
pitch like a screw thread which, when driven by a shaft, forces the
vessel to move.
A large section of flooring in the mold loft on which the frame
molded lines of the ship are drawn in full size.
Pipe connected to deck scupper to allow water to run below decks, to
prevent waste water flowing down the sides of ship.
Openings in the shell plating just above deck plating to allow water
to run overboard.
A small hatch.
The line where the edges of plates meet when joining each other.
A drawing representing the internal parts of a vessel as if she had
been cut straight through, either longitudinally or athwartships.
A watertight passage, housing the propeller shafting from the engine
room to the bulkhead at which the stern tubes commence. 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.
SHAFT ALLEY TUNNEL
An enclosure of watertight construction, extending along the middle
of engine room bulkhead on tank top to the stuflfing box, at the after
end. It contains the shaft which is elevated.
An extra tail shaft. (Steamers generally carry one or more stowed in
the shaft alley.)
A term applied to a bracket supporting the after end of the propeller
shaft and the propeller in twin or multiple screwed vessels having
propeller shafts fitted off from the center line.
Cutting or trimming the edges of steel member.
The upward curvature of the lines of a vessel toward the bow and
A vertical longitudinal center line section of a vessel.
The topmost strake of shell plating extending from stem to stern.
The outside plating of a ship from stem to stern.
SHELL DOUBLING OR DOUBLER
An extra plate added to strengthen the shell.
The plating forming the outer skin of a vessel.
SHELTER DECK OR WEATHER DECK
The top deck of a vessel reaching from shell to shell.
A piece of metal or wood placed under the bedplate or base of a
machine or fitting for the purpose of truing it up.
A mechanic who makes templates, marks, assembles, and fastens in
place plates and shapes for the hull of a ship. Should be able to do any
fitting on ship.
A book with a record of every occurrence and incident concerning the
A ship builder, or one who works about a ship. Does wood carpentry on
the ship and keeps ships faired. Builds launching ways and launches
One of the many wooden props by which the ribs or frames of a vessel
are externally supported while building, or by which the vessd is held
upright on the ways.
The act of supporting anything by shoring it up.
Devices for attaching shrouds or guy cables to crosstree and bulwark.
SKELETON (OF A VESSEL)
The hull without the outside and inside plating.
The plating of a ship.
A framing of metal fitted over an opening in a deck, with window
glass inserted for the admission of light into a cabin, engine room,
A structure of heavy timbers placed between ground ways and cradle to
support the ship during launching.
An opening in the lower part of a bulkhead fitted with a sliding
watertight gate or door having an operating rod extending to the upper
deck or decks.
A plate put on over a break or hole, and secured with stud bolts. It
is made watertight with a gasket such as canvas saturated with red lead.
A pipe leading from main deck to double bottom of sufficient size to
allow a round piece of metal attached to a line to be lowered to
ascertain the amount of liquid in the double bottom.
SPACING OF RIVETS
The distance from the center of one rivet hole to the center of the
next, depending on the diameter of the rivets and the purpose for which
they are employed.
A pole used for a hoist or in scaffolding.
The curve of a plate or strake as it narrows to a point.
A flexible strip used for fairing lines.
A vertical plate on center line of nose plate above stem casting.
Indicates that an annular facing has been made about a bolt hole to
allow a nut or head to seat evenly.
The tendency in a boat to keep an upright position or to return to it
when careened over.
A platform of boards or planks, hung in ropes or otherwise supported
for a person to stand upon when leaning, scraping or painting the
outside or inside of a vessel.
To zigzag a line, or row of rivet holes, etc.
STAGGERED OR ZIGZAG RIVETING
Two rows of riveting with alternating spaces.
A pillar or iron post for supporting the decks, etc.
STAPLING COLLARS OR STAPLES
Forged angle bars fitted around continuous members passing through
bulkheads or decks, for watertightness or oiltightness.
The right-hand side, looking from aft forward
Bars used for binding or supporting or holding parts together.
STEALER OR STEALER PLATE
A plate taking two strakes used near either end of the ship.
The after part of a vessel having the poorest accommodations and
occupied by the steerage passengers, or those paying the lowest fare.
STEERING GEAR FLAT
The deck above the stern overhang, on which the rudder steering
mechanism is installed.
The bow of the ship, the part where the port and starboard meet up
The after or rear end of the vessel.
STERN CASTING OR FRAME
A heavy steel casting or forging at stern of vessel supporting the
rudder and to which the shell plate strakes are fastened.
A massive casting of special design, shaped to allow the propeller
blades to revolve. The rudder is fitted on the after post.
The bearing which supports the propeller shaft where it emerges from
the ship. A cast stee1 cylinder, fitted with brass bushings which are
lined with lignum vitae or metal bearing surfaces, upon which the propeller
shaft, enclosed in a brass sleeve, rotates.
An angle bar or stringer fastened to a surface to strengthen it and
make it rigid.
STOPWATER (In riveted ships)
A packing of felt or canvas and red lead to prevent water from
passing through metal parts where calking is impracticable.
STOPWATER (In welded ships)
A plug weld where a hole was cut through a plate at a point opposite
which a butt of plates occurs. It is used to make a tight joint.
A continuous row of plates.
A longitudinal stiffener for the side of a ship, made of angle bar,
bulb angle channel or plates, etc. Depending upon their locations,
stringers are known as bilge stringers, side stringers, hole stringers,
The outboard strake of plates next to the shell.
A channd or flanged plate used in making the sides of a set of
A bar for locking cargo port doors and watertight scuttles.
A portable beam to hold hatch covers and deck loads.
STRONG BEAM OR TROLLEY BEAM
A portable beam over engine and boiler room space in the engine and
boiler room casing carrying a travelling hoist.
Strips of flat iron used to brace one part with another.
A forecastle partly above and partly below the level of an upper
A poop set part way down into the 'tween decks. In a case of this
kind, the poop deck is but a little above the next deck forward.
Any structure built above the top full deck, such as a deck house,
Longitudinal or transverse bulkheads fitted in a tank to decrease the
swerving action of the water. 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 fitted in a tank to retard the flow or surge of liquid cargo
or ballast when the ship rolls or pitches.
Marks of identiflcation.
The aft section of the shaft which received the propellers.
Are of two kinds: Flrst, those built in permanently and part of the
ship's structure, used for the reception of water ballast, fuel, oil, or
liquid cargo; second, those constructed specially and removable if
necessary. These vary greatly in size and shape and the purpose for
The plating laid on the floors of a ship which forms the top side of
the tank sections or double bottom.
TANK VESSEL (TANKER)
A vessel specially constructed and equipped with tanks for carrying
liquids in bulk.
To cut threads inside of a hole. A tool for tapping.
TEE IRON, TEE BAR
Bar iron with cross section like the letter "T."
Patterns made in the mold loft from wood strips, cardboard, or heavy
A bulkhead fitted for temporary purposes.
Flat bar or plate brackets placed at various points on deck girders,
beams, stiffeners or longitudinals as reinforcement.
The edge of a flange on a bar.
The tongue of a stern post or propeller post is the raised middle
section which is fastened to the vertical keel. As a rule the tongue is
raised twice as high as the sides of the dished keel.
A measure of a vessel's interior volume.
The last transverse frame of a ship's structure. The cant frames,
usually normal to the round of the stern, connect with it.
The plate between the fantail and the hull.
Placed at right angles to the keel, such as a transverse frame,
transverse bulkhead, etc. See also abeam and athwart.
A bulkhead placed athwartships.
A step in a stairway.
TRIMMING TANKS, PEAK TANKS
Tanks at the extreme ends of a vessel. By filling or emptying one or
the other, a ship may be easily trimmed by the head or stern as
To fasten by three rows of rivets.
A flat plate fitted to the stern post and flanged to take strakes of
The distance the ship's side falls in towards the center line above
the load water line. (Opposite to flare.)
The elevated and extended after portion of a tunnel.
A form of engine in which all driving parts rotate. There are various
types in marine use.
Used to pull objects together. A link threaded on both ends of a
short bar, one left-handed, the other right-handed.
The top of a wheelhouse, forecastle, etc., having the form of a
The space between any decks.
A metal shield in the form of a frustrum of a cone, fitted to the
outer casing of the smokestack over the air casing to keep out the
Superstructures, or deck erections located on or above the weather
deck. Sometimes used with reference to a ship's entire above-water
The part connecting smoke box to funnel. Sometimes the term is used
to include the smokebox.
A device for furnishing fresh air to compartments below deck or
exhausting foul air.
VERTICAL CENTER KEELSON, VERTICAL KEEL
A keelson of strong vertical plates fitted at the center line upon
the keel and to which the (half) floor plates are con. nected by welding
or by vertical angle bars.
The motion of water left by a moving ship.
WALKWAY OR CAT WALK
Used on oil tankers. An elevated runway from poop to midship, and
midship to fore castle deck. It affords means of safe passage for crew
members when deck is awash in stormy weather.
Sea water used for ballast, let into the double bottom, or into a
water-ballast tank, or trimming tanks.
WATER BALLAST TANKS
Tanks in the double bottom used for ballast.
Lines drawn parallel with the surface of the water at varying heights
on a ship's outline. In the sheer plan, they are straight and
horizontal; in the halfbreadth plan they show the form of the ship at
each of the successive heights marked.
WATER LINE LIGHT
The line to which a vessel is submerged without cargo on board.
WATER LINE LOADED
The line to which a vessel is submerged with full cargo.
A bulkhead that will not let water pass from one side of it to the
A compartment having a watertight bulkhead at each end.
A gutter at the edge of a deck for draining water to scuppers.
WATERWAY BAR OR GUTTER ANGLE BAR
An angle or flat bar attached to a deck stringer plate forming the
inboard boundary of a waterway and serving as an abutment for the wood
The framework of timber, etc., on which a vessel is built, from which
she is launched into the water.
A deck exposed to the wind and sea, i.e., not fully covered by a deck
above and with side plating coming up to it.
The plate or its equivalent in a beam or girder, which connects the
upper and lower flat orates nr laterally extending members.
A frame built up transversely with a plate or plates to give greater
Tapered pieces of wood or iron, used extensively to force parts into
When water oozes through the seams of a vessel's shell, or a steam
boiler, etc., they are said to weep.
Connecting two separate pieces of steel, iron or other metal with a
gas flame or an electric arc, so that they become all one piece.
That portion of any upper deck (weather deck) -between a bridge and a
WELL DECK VESSEL
A vessel having a long poop, or raised quarter-deck, and the bridge
house combined, and a forecastle; the deepening between these structures
forming the "well."
A house over the wheel.
A machine used for loading and discharging cargo, or for hauling in
A drum (usually of small diameter and concave) on a winch. Designed
for taking and holding the turns of a rope.
A special form of winch used to hoist the anchors. It has two drums
designed to grab the links of the anchor chains and is fitted with
ratchet and braking device suitable for "paying out" chain.
Tanks formed by abell and bulkheads, not reaching to center line
Tasks performed by the volunteers on the BROWN.
Steel bars with cross section like letter "Z."